BARRELS

XXXIII

Wednesday, October 21

Thursday, October 22

Friday, October 23

, 2020

Table of Contents

BARRELS XXXIII – 2020

Contents…………………………………………………………………………1

A Special Thanks……………………………………………………………….2

Barrels Program, Overview………..…………………………………………..3

Barrels Program/Invited Speakers & Platform Talks………………………..8

Poster Session Schedule………………………………………………………22

Poster Abstracts…………………………………….…………………………..23

Participant List…………………………………………………………………..32

A SPECIAL THANK YOU to:

The Organizing Committee:

Solange Brown, MD, Ph.D., Johns Hopkins University

Joshua C. Brumberg, Ph.D., The Graduate Center and Queens College, CUNY

Randy Bruno, Ph.D., Columbia University

Mitra Hartmann, Ph.D., Northwestern University

S. Andrew Hires, Ph.D., University of Southern California

David Kleinfeld, Ph.D., University of California, San Diego

Dan O’Connor, Ph.D., Johns Hopkins University

Robert Sachdev, Ph.D., Humboldt University, Germany

Gordon Shepherd, MD, Ph.D., Northwestern University

Jochen Staiger, M.D., Georg-August-Universirtaet

Conference Support Assistance:

Drew Baughman

Esther Greeman

Gordon Petty

WELCOME TO Barrels XXXIII – 2020!

BARRELS XXXIII Program

October 21

- October 23

2020

The 33

Annual Barrels Society Meeting

Wednesday, October 21 (All times EDT)

11:30 – 12:00 Check-in (Please login closer to 11:30 as you must be admitted to the meeting)

12:00 – 12:10 Welcome: Randy Bruno

Zuckerman Institute, Columbia University

12:10 – 1:00 Keynote 1: Silvia Arber, Introduced by Daniel Huber

FMI and University of Basel

Disentangling brainstem motor circuits

1:00 – 1:20 Coffee Break (randomized break-out rooms)

Session 1: Mouse forelimb as a model system

1:20 – 1:30 Moderator introduction: Gordon Shepherd

Northwestern University

1:30 – 2:00 Daniel Huber

University of Geneva

Do mice ‘hear’ with their limbs?

2:00 – 2:30 Alice Mosberger

Zuckerman Institute, Columbia University

Discovery and refinement of forelimb actions in mice

2:30 – 3:00 Abigail Person

University of Colorado

Beyond learning: the cerebellum and predictive control

3:00 – 3:20 Discussion

3:20 – 3:40 Coffee Break (randomized break-out rooms)

Short Platform Talks 1 (10 min including questions)

Moderated by Mitra Hartmann, Northwestern University

3:40 – 3:50 Nicholas E. Bush

Seattle Children's Research Institute

Continuous, multidimensional coding of 3D complex tactile stimuli by

primary sensory neurons of the vibrissal system

3:50 – 4:00 Krithiga Aruljothi

UC Riverside

Functional Localization of an Attenuating Filter within Cortex for a Selective

Detection Task in Mice

4:00 – 4:10 Christian Waiblinger

Georgia Institute of Technology

The comeback of S1 – A journey from sensory representation to behavioral

flexibility

Moderated by Christopher Moore, Brown University

4:10 – 4:20 Yaroslav Sych

Brain Research Institute, University of Zurich

Mesoscale brain dynamics reorganizes and stabilizes during learning

4:20 – 4:30 Valerie Ego-Stengel

NeuroPSI, CNRS

Cortical closed-loop brain-machine interface requires biomimetic sensory

feedback

4:30 – 4:40 Scott Pluta

Purdue University

Sensorimotor integration in the superior colliculus during whisker-guided

orienting behavior

4:40 – 6:00 Virtual Poster Session

Thursday, October 22 (All times EDT)

11:30 – 12:00 Check-in (Please login closer to 11:30 as you must be admitted to the meeting)

Session 2: Active sensation

12:00 – 12:10 Moderator introduction: Solange Brown

Johns Hopkins University

12:10 – 12:40 David Kleinfeld

University of California, San Diego

The coordinates of active vibrissa touch and their representation in L4 of vS1

cortex

12:40 – 1:10 Soohyun Lee

National Institute of Mental Health

Brain-wide neural networks of movement-encoding neurons in the primary

somatosensory cortex

1:10 – 1:40 Daniel O’Connor

Johns Hopkins University

Active tongue sensing

1:40 – 2:10 Carl Petersen

EPFL, Switzerland

Cholinergic modulation of wS1 during whisking

2:10 – 2:30 Discussion

2:30 – 2:50 Coffee Break (randomized break-out rooms)

Short Platform Talks 2 (10 min including questions)

Moderated by Joshua Brumberg (CUNY)

2:50 – 3:00 Jung M Park

Zuckerman Institute, Columbia University

Deep and superficial layers of the primary somatosensory cortex are

indispensable for whisker-based texture discrimination in mice

3:00 – 3:10 Lara Rogerson-Wood

The University of Sydney

Enhanced targeted microglial-mediated-phagocytosis underlies environmental

enrichments capacity to facilitate the corrective remodeling of a murine

subcortical axonal-guidance defect

3:10 – 3:20 Ben Efron

Weizmann Institute of Science

Auditory response to sounds originating from whisking against objects

Moderated by Cornelius Schwarz (Univ Tuebingen)

3:20 – 3:30 Silvana Valtcheva

New York University School of Medicine

Hypothalamic oxytocin neurons respond to infant vocalizations via

noncanonical auditory pathway

3:30 – 3:40 Tamura Keita

Brain Mind Institute, EPFL

Cortical signal flow during sensorimotor transformation in a whisker

detection and delayed lick task

3:40 – 3:50 Ewoud Schmidt

Zuckerman Institute, Columbia University

A human-specific modifier of cortical circuit connectivity and function improves

sensory discrimination in mice

Moderated by Garrett Stanley (Georgia Tech)

3:50 – 4:00 Yasir Gallero-Salas

Brain Research Institute, University of Zurich

Sensory and behavioral components of neocortical signal flow in tactile

and auditory discrimination tasks with short-term memory

4:00 – 4:10 Cameron Condylis

Boston University

Multiplexed functional and transcriptional readout of mouse primary

somatosensory cortex during behavior

4:10 – 4:20 Christian L. Ebbesen

New York University

Automatic tracking of mouse social posture dynamics by 3D videography, deep

learning and GPU-accelerated robust optimization

4:20 – 4:30 Jim McBurney-Lin

University of California, Riverside

Bidirectional pharmacological perturbations of the noradrenergic system

differentially affect tactile detection

4:30 – 6:00 Virtual Poster Session

Friday, October 23 (All times EDT)

11:30 – 12:00 Check-in (Please login closer to 11:30 as you must be admitted to the meeting

12:00 – 12:50 Keynote 2: Nadine Gogolla, Introduced by Robert Sachdev

Max Planck Institute, Martinsried

Facial expressions and their neuronal correlates in mice

12:50 – 1:00 Coffee Break (randomized break-out rooms)

Session 3: Reorganization of neuronal representations

1:00 – 1:10 Moderator introduction: Dan Feldman

University of California, Berkeley

1:10 – 1:40 Andrew Hires

University of Southern California

Behavioral and neuronal bases of tactile shape discrimination learning in

head-fixed mice

1:40 – 2:10 Simon Peron

New York University

Barrel cortex dynamics during optical microstimulation task training

2:10 – 2:40 Carsen Stringer

Janelia Research Campus

A neural atlas of multi-dimensional behavioral representations

2:40 – 3:00 Discussion

3:00 – 3:20 Coffee Break

Short Platform Talks 3 (10 min including questions)

Moderated by Robert Sachdev (Humboldt University)

3:20 – 3:30 Nathaniel C. Wright

Georgia Institute of Technology

Rapid sensory adaptation in the mouse thalamocortical circuit during

wakefulness, and the relative contribution of thalamic state

3:30 – 3:40 Jan Jabłonka

University of Warsaw

Interhemispheric interactions participate in the cortical plasticity

3:40 – 3:50 Marcel Oberlaender

Max Planck Society

Thalamus gates top-down modulation of cortical output

Moderated by Kate Hong (Carnegie Mellon University)

3:50 – 4:00 Mikkel Vestergaard

Max-Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC)

The cellular coding of temperature in the mammalian cortex

4:00 – 4:10 Alan Urban

Neuro-Electronics Research Flanders

A platform for brain-wide functional ultrasound imaging and analysis of

circuit dynamics in behaving

4:10 – 4:20 Yuri Vlasov

University of Illinois at Urbana-Champaign

High-frequency whisker vibrations above 1KHz - are they relevant to perception?

4:20 – 4:30 Wrap-up discussion & Poll

4:30 – 6:00 Virtual Poster Session

ADJOURN

BARRELS XXXIII Program

October 21

- October 23

2020

The 33

Annual Barrels Society Meeting

Wednesday, October 21 (All times EDT)

11:30 – 12:00 Check-in (Please login closer to 11:30 as you must be admitted to the meeting)

12:00 – 12:10 Welcome: Randy Bruno

Zuckerman Institute, Columbia University

12:10 – 1:00 Keynote 1: Silvia Arber, Introduced by Daniel Huber

FMI and University of Basel

Disentangling brainstem motor circuits

1:00 – 1:20 Coffee Break (randomized break-out rooms)

Session 1: Mouse forelimb as a model system

1:20 – 1:30 Moderator introduction: Gordon Shepherd

Northwestern University

1:30 – 2:00 Daniel Huber

University of Geneva

Do mice ‘hear’ with their limbs?

I will present our most recent studies suggesting that pallesthesia (the sense of vibrations) and hearing have

much more in common than previously thought. Our data shows that substrate vibrations are not perceived

simply as frequencies, but also as "pitch", similar to hearing. More importantly, we were able to reveal the

common computational principle of how physical stimulus attributes influence the perception of vibro-tactile

pitch: Using matched psychophysical experiments in mice and humans forelimbs we demonstrate that pitch

perception is shifted with increases in amplitude toward the frequency of highest vibrotactile sensitivity in both

species. Vernon Mountcastle's V-shaped somatosensory sensitivity curves are thus put into a very new

perspective.

2:00 – 2:30 Alice Mosberger

Zuckerman Institute, Columbia University

Discovery and refinement of forelimb actions in mice

Many actions are learned from reinforcement by assigning credit to successful movements. For

complex, continuous movements, this process allows the gradual refinement of an action into a

skill. The neural mechanism of such refinement is only poorly understood as it has not been

studied in an animal model that allows functional circuit dissection.

Classical rodent studies on reinforcement have used discrete action choice tasks that

measure changes in the rate of the correct action, but cannot resolve changes in the shape of the

movement itself – a hallmark of refinement.

To overcome this, I have developed a novel task, in which head-fixed mice move a low-friction

planar joystick. Here mice generate complex trajectories with their forelimb while searching for a

hidden reinforced target location. Using pure outcome reinforcement, mice learn to efficiently

move the joystick into different targets by refining trajectory shape.

Using this task, I am dissecting the neural mechanism of refinement through reinforcement.

Classically, learning from reinforcement is thought to be implemented in the corticostriatal

circuitry. Sensorimotor cortex is proposed to convey a motor command to striatum, that is

assigned with credit by dopamine-dependent plasticity. But projections from cortex to striatum are

heterogeneous, spanning multiple cortical areas and distinct cell types (pyramidal tract (PT) and

intratelencephalic (IT) neurons). It is currently unknown which of these are reinforced to allow

refinement of the shape of a continuous action.

I have anatomically characterized this forelimb corticostriatal network in the mouse and am

currently decoding the cortical motor commands that are sent to striatum during continuous

forelimb movements using my joystick task. Together with optogenetic probing of the necessity

of the corticostriatal motor command for action refinement, these experiments bring us closer to

understanding the mechanisms and circuitry for reinforcement learning.

2:30 – 3:00 Abigail Person

University of Colorado

Beyond learning: the cerebellum and predictive control

The cerebellum is well appreciated to impart speed, smoothness, and precision to skilled movements such as

reaching. How these functions are executed by the final output stage of the cerebellum, the cerebellar nuclei,

remains unknown. In this talk, I will discuss our data identifying a causal relationship between cerebellar output

and mouse reach kinematics and show how that relationship is leveraged endogenously to enhance reach

precision. I will discuss how our results provide a framework for understanding the physiology and

pathophysiology of the intermediate cerebellum during precise skilled movements.

3:00 – 3:20 Discussion

3:20 – 3:40 Coffee Break (randomized break-out rooms)

Short Platform Talks 1 (10 min including questions)

Moderated by Mitra Hartmann, Northwestern University

3:40 – 3:50 Nicholas E. Bush, Mitra J.Z. Hartmann, Sara A. Solla

Seattle Children's Research Institute, Northwestern University

Continuous, multidimensional coding of 3D complex tactile stimuli by

primary sensory neurons of the vibrissal system

In the rodent vibrissal system, responses of primary sensory neurons in the trigeminal ganglion (Vg) have long

been thought to segregate into functional classes. However, this view is based on studies that have used only

2D analyses and restricted stimulus sets. Here we begin to reveal the full representational capabilities of Vg

neurons by recording their responses to complex 3D stimulation while quantifying the complete 3D whisker

shape and mechanics. Results show that individual Vg neurons simultaneously represent multiple mechanical

features of the stimulus, do not preferentially encode principal components of the stimuli, and represent

continuous and tiled variations of all available mechanical information. These results directly contrast with

proposed codes in which subpopulations of Vg neurons encode select stimulus features. Instead, individual Vg

neurons likely encode large regions of the complex sensory space. This proposed tiled and multidimensional

representation at the Vg directly constrains the computations performed by more central neurons of the

vibrissotrigeminal pathway. Funding: R01-NS093585 to M.J.Z.H. and S.A.S., F31-NS092335 to N.E.B.

3:50 – 4:00 Krithiga Aruljothi, Krista Marrero, Zhaoran Zhang, Behzad Zareian, Edward Zagha

UC Riverside

Functional Localization of an Attenuating Filter within Cortex for a Selective

Detection Task in Mice

An essential feature of goal-directed behavior is the ability to selectively respond to the diverse stimuli in one's

environment. However, the neural mechanisms that enable us to respond to target stimuli while ignoring

distractor stimuli are poorly understood. To study this sensory selection process, we trained male and female

mice in a selective detection task in which mice learn to respond to rapid stimuli in the target whisker field and

ignore identical stimuli in the opposite, distractor whisker field. In expert mice, we used widefield Ca2+ imaging

to analyze target-related and distractor-related neural responses throughout dorsal cortex. For target stimuli,

we observed strong signal activation in primary somatosensory cortex (S1) and frontal cortices, including both

the whisker region of primary motor cortex (wMC) and anterior lateral motor cortex (ALM). For distractor

stimuli, we observed strong signal activation in S1, with minimal propagation to frontal cortex. Our data support

only modest subcortical filtering, with robust, step-like attenuation in distractor processing between mono-

synaptically coupled regions of S1 and wMC. This study establishes a highly robust model system for studying

the neural mechanisms of sensory selection and places important constraints on its implementation. Funding:

Whitehall Foundation (Research 18 Grant 2017-05-71 to E.Z.) and the National Institutes of Health

(R01NS107599 to E.Z.)

4:00 – 4:10 Christian Waiblinger, Michael F Bolus, Peter Y Borden, Garrett B Stanley.

Georgia Institute of Technology, Emory University

The comeback of S1 – A journey from sensory representation to behavioral

flexibility

Behavioral flexibility is crucial for survival in a constantly changing environment. What are the neuronal

processes that recalibrate perception and transform a stimulus into an action? The mouse model has

become indispensable for answering this question, yet it is still unclear whether components associated with

learning and behavior emerge in the early sensory system or elsewhere. Here, we investigate perceptual

changes in the S1 of the mouse during learning and behavioral adaptation. We performed chronic wide-field

imaging with a genetically encoded voltage indicator (GEVI) in mice undergoing a sequence of

psychophysical tests including a learning phase and a detection task for controlled whisker deflections with

changing sensory contingencies. Our results reveal that S1 correlates with behavioral changes in a way that

is experience dependent. During learning, S1 sensitivity is mostly stimulus driven and resistant to changes in

performance, reflective of a relatively static sensory representation of whisker inputs. However, once an

animal reaches expert level and is challenged with a change in stimulus statistics, S1 activity exhibits clear

changes in the representation of the same vibrissa input in different contexts. The change is more

pronounced at a later training stage with more experience. This suggests that the role of S1 in detection

behavior is dynamic and dependent upon the nature of the task and its context. Funding: NIH R01NS085447,

R01NS104928, U01NS094302

Moderated by Christopher Moore, Brown University

4:10 – 4:20 Yaroslav Sych, Aleksejs Fomins, Leonardo Novelli, and Fritjof Helmchen*

Brain Research Institute, Neuroscience Center, University of Zurich.

Mesoscale brain dynamics reorganizes and stabilizes during learning

Adaptive behavior is coordinated by neuronal networks that are distributed across multiple brain regions.

How cross-regional interactions reorganize during learning remains elusive. We applied multi-fiber

photometry to chronically record simultaneous activity of 12-48 mouse brain regions while mice learned a

tactile discrimination task. We found that with learning most regions shifted their peak activity from reward-

related action to the reward-predicting stimulus. We corroborated this finding by functional connectivity

estimation using transfer entropy, which revealed growth and stabilization of mesoscale networks

encompassing basal ganglia, thalamus, cortex, and hippocampus, especially during stimulus presentation.

The internal globus pallidus, ventromedial thalamus, and several regions in frontal cortex emerged as hub

regions. Our results highlight the cooperative action of distributed brain regions to establish goal-oriented

mesoscale network dynamics during learning.

4:20 – 4:30 Aamir Abbasi, Luc Estebanez, Dorian Goueytes, Henri Lassagne, Daniel E. Shulz,

Valerie Ego-Stengel

NeuroPSI, CNRS and University Paris-Saclay, France

Cortical closed-loop brain-machine interface requires biomimetic sensory

feedback

New and improved neuroprosthetics offer great hope for motor-impaired human patients to regain autonomy.

One obstacle facing current technologies is that fine motor control requires near-instantaneous somatosensory

feedback. The way forward is to artificially recreate the rich, distributed feedback generated by natural

movements. Here, we hypothesize that incoming sensory feedback needs to follow biomimetic rules in order to

be efficiently integrated by motor circuits. We have developed a rodent closed-loop brain-machine interface

where head-fixed mice were trained to control a virtual cursor by modulating the activity of motor cortex

neurons. Artificial feedback consisting of precise optogenetic stimulation patterns in the primary

somatosensory cortex coupled to the motor cortical activity was provided online to the animal. We found that

learning occurred only when the feedback had a topographically biomimetic structure. Shuffling the

spatiotemporal organization of the feedback prevented learning the task. These results suggest that the

patterns of inputs that are structured by the body map present in the primary somatosensory cortex of all

mammals are essential for sensorimotor processing and constitute a backbone that needs to be considered

when optimizing artificial sensory feedback for fine neuroprosthetic control. Funded by FRM (Equipe FRM

DEQ20170336761), CNRS (80|Prime), ANR Neurowhisk, Lidex NeuroSaclay, Idex Brainscopes and iCODE,

and FRC (AAP 2018).

4:30 – 4:40 Scott Pluta

Purdue University

Sensorimotor integration in the superior colliculus during whisker-guided

orienting behavior

Spatial attention involves the parallel integration of multiple, disparately organized neural circuits. These

disparate circuits ultimately converge onto the midbrain superior colliculus (SC), where individual neurons

encode the location of stimuli, sustain working memory and initiate overt movements. However, the role of the

SC in active, somatosensory-guided movements is largely unknown. Since mice do not track objects by

moving their eyes, somatosensory-guided whisker movements provide a unique opportunity for greatly

advancing our mechanistic understanding of overt spatial attention. To probe this topic, we recorded spiking

from the SC while mice used their whiskers to explore the surface of a dynamically moving object. Mice

dynamically optimized their whisking set-point and amplitude to track object movement. Many neurons in the

SC responded to surface movement with an increase in spiking, while others decreased their activity, in a

location-dependent manner. Overall, we observed a clear preference for a particular trajectory of surface

movement. Trajectory tuning was consistent with neuron-specific preferences for whisker curvature and phase

during touch. Spiking in a subset of neurons located in the deepest, motor layer of the SC predicted whisk

amplitude. Overall, these data help establish the rodent whisker system as a valuable model for dissecting the

neural circuits underlying overt spatial attention.

4:40 – 6:00 Virtual Poster Session

Thursday, October 22 (All times EDT)

11:30 – 12:00 Check-in (Please login closer to 11:30 as you must be admitted to the meeting)

Session 2: Active sensation

12:00 – 12:10 Moderator introduction: Solange Brown

Johns Hopkins University

12:10 – 12:40 David Kleinfeld

University of California, San Diego

The coordinates of active vibrissa touch and their representation in L4 of vS1

cortex

I will present preliminary behavioral data showing that the angle of vibrissa contact with an object, known to be

proportional to contact force, is also proportional to phase in the whisk cycle. This proportionality among three

quantities resolves many of the discrepancies reported across different laboratories for the decoding of active

touch by the vibrissae. I will further present preliminary data from glutamate imaging studies showing that

individual thalamocortical boutons, known to form an ordered arranged for each vibrissa within L4, represent

touch by phase in the whisk cycle. Similar results are seen in preliminary data from voltage imaging of L4

excitatory cells. We suggest that the phase preference of L4 neurons can function as a labeled line to identify

contact angle; the role of L4 cells in directing read-out and feedback control is under investigation. Work by Rui

Liu in collaboration with Amalia Callado Perez, Martin Deschênes, and Pantong Yao. Supported by NINDS

grants NS097265 and NS107466.

12:40 – 1:10 Soohyun Lee

National Institute of Mental Health

Brain-wide neural networks of movement-encoding neurons in the primary

somatosensory cortex

Principal neurons in the primary sensory cortices exhibit heterogeneous patterns of activity, not only in

response to sensory stimuli but also, during spontaneous movements. Yet, how these heterogeneous,

behavioral state-dependent patterns of activity arise is largely unknown. Longitudinal two-photon calcium

imaging uncovered a remarkably stable correlation between the activity of principal neurons in layers II/III of

primary somatosensory cortex and spontaneous movements. This population activity could reliably predict

spontaneous movements, but with a subset of neurons accounting for most of the prediction accuracy. The

activity of movement-encoding neurons cannot be explained by sensory feedback, as paralysis of the

contralateral whisker pad did not disrupt correlation with ipsilateral whisker movements and locomotion. During

pharmacological blockade of neuromodulators, the activity levels were altered, but the correlation of neuronal

activity with spontaneous movements was largely maintained. By contrast, glutamatergic transmission blockers

nearly abolished this correlation. Single cell-initiated monosynaptic retrograde tracing and whole-brain

presynaptic network analysis revealed that movement-encoding neurons receive characteristic subcortical

inputs. Our study provides a connectivity rule that supports the representation of spontaneous movements in

the primary somatosensory cortex. Funding: NIH Intramural Research Program.

1:10 – 1:40 Daniel O’Connor

Johns Hopkins University

Active tongue sensing

The brain generates complex sequences of movements that can be flexibly reconfigured in real-time based on

sensory feedback, but how this occurs is not fully understood. We developed a novel ‘sequence licking’ task in

which mice directed their tongue to a target that moved through a series of locations. Mice could rapidly

reconfigure the sequence online based on tactile feedback. Closed-loop optogenetics and electrophysiology

revealed that tongue/jaw regions of somatosensory (S1TJ) and motor (M1TJ) cortex encoded and controlled

tongue kinematics at the level of individual licks. Tongue premotor (anterolateral motor, ALM) cortex encoded

intended tongue angle in a smooth manner that spanned individual licks and even whole sequences, and

progress toward the reward that marked successful sequence execution. ALM activity regulated sequence

initiation, but multiple cortical areas collectively controlled termination of licking. Our results define a functional

cortical network for hierarchical control of sensory- and reward-guided orofacial sequence generation.

1:40 – 2:10 Carl Petersen

EPFL, Switzerland

Cholinergic modulation of wS1 during whisking

Rodents actively acquire tactile information about object location, shape and texture by moving their mystacial

whiskers back and forth to scan their immediate facial environment. There are obvious differences in neuronal

activity comparing periods of active whisker sensing (whisking) and periods of quiet wakefulness (when the

whiskers are not moving). Previous work reported that increased thalamic (Poulet et al., 2012) and cholinergic

(Eggermann et al., 2015) input to wS1 might be key drivers of the changes in cortical state induced by whisking

(Crochet & Petersen, 2006; Poulet & Petersen, 2008). In this talk, I will focus on the impact of acetylcholine

released during whisking upon distinct cell-types in layer 2/3 of mouse barrel cortex. We made two-photon

targeted whole-cell membrane potential recordings from excitatory neurons and various types of genetically-

defined subtypes of GABAergic neurons. We found that VIP neurons (but not 5HT3AR-non-VIP neurons, PV

neurons, SST neurons or excitatory neurons) received a prominent nicotinic excitation during active whisking

and in response to whisker deflection. VIP neurons are typically considered to play a disinhibitory role in

cortical function through their inhibition of SST and PV neurons. To test this hypothesis, we carried out

pharmacological and optogenetic manipulations revealing likely important contributions of cholinergic-driven

VIP-mediated disinhibition to whisker sensory processing. Increased acetylcholine concentrations during active

sensorimotor processing may help integration of top-down and motor-related signals in wS1, as well as

promoting synaptic plasticity, for example enhancing fire-together-wire-together synaptic plasticity between

neurons in interacting cortical regions during goal-directed sensorimotor learning.

2:10 – 2:30 Discussion

2:30 – 2:50 Coffee Break (randomized break-out rooms)

Short Platform Talks 2 (10 min including questions)

Moderated by Joshua Brumberg (CUNY)

2:50 – 3:00 Jung M Park, Y. Kate Hong*, Chris C, Rodgers*, Jacob B. Dahan, Ewoud RE Schimdt,

Randy Bruno

Zuckerman Institute, Columbia University. *Contributed equally as co-second authors

Deep and superficial layers of the primary somatosensory cortex are

indispensable for whisker-based texture discrimination in mice

The neocortex, comprised of multiple distinct layers, processes sensory input from the periphery, makes

decisions, and executes actions. Despite extensive investigation of cortical anatomy and physiology, the

contributions of different cortical layers to sensory guided behaviors remain unknown. Here, we developed a

two-alternative forced choice (2AFC) paradigm in which head-fixed mice use a single whisker to either

discriminate textures of parametrically varied roughness or detect the same textured surfaces. Lesioning the

barrel cortex revealed that 2AFC texture discrimination, but not detection, was cortex-dependent. Paralyzing

the whisker pad had little effect on performance, demonstrating that passive can rival active perception and

cortical dependence is not movement-related. Transgenic Cre lines were used to target inhibitory opsins to

excitatory cortical neurons of specific layers for selective perturbations. Both deep and superficial layers were

indispensable for texture discrimination. We conclude that even basic cortical computations require

coordinated transformation of sensory information across layers. Funding was provided by NIH R01 NS094659

(RMB); NSF GRFP and T32NS064928 (JMP); NIH F32 NS084768 and T32 MH015174 (YKH); and NIH F32

NS096819, Kavli Institute Postdoctoral Fellowship, and Brain & Behavior Research Foundation Young

Investigator Award (CCR).

3:00 – 3:10 Lara Rogerson-Wood, Atomu Sawatari, Catherine A. Leamey

The University of Sydney

Enhanced targeted microglial-mediated-phagocytosis underlies environmental

enrichments capacity to facilitate the corrective remodeling of a murine

subcortical axonal-guidance defect

Our lab has shown murine environmental enrichment (EE) from birth partially corrects a subcortical miswiring

caused by removal of an axonal-guidance cue (Ten-m3) with, an associated rescue of visually mediated

behavior. This effect appeared mediated by ectopic projection removal after target (rostral dLGN) innervation.

Further, comparison of effect magnitude at 6 weeks-postnatal (wp) with 3.5 wp indicated this mechanism was

active at 3.5 wp, although the cellular mechanisms were unclear. We hypothesized that microglia – an

immune cell with key roles in structural plasticity – mediated this through targeted phagocytosis of ectopic

projections. Observation of microglia was undertaken at 3.5 wp in the rostral dLGN of standard-housed Ten-

m3 knock-out mice (SH-KOs; n=5) and those enriched from birth (EE-KOs; n=5). Microglia localized around

the characterized site of projection removal displayed a distinct-phenotype in EE-KOs; Quantitative

comparison with SH-KOs revealed these microglia had an enhanced phagocytic-like profile – increased

density (p=.038) and CD68 expression (p=.011) and, a more ameboid morphology (p=.009) – and, elevated

levels of phagocytosis - increased density (p=.001) and proportion (p=.003) of projection-containing microglia

and, an increased phagocytosed volume per microglial volume (p=0.016). These results support a model

whereby EE elicits the corrective re-modelling of this subcortical miswiring through enhancing targeted

microglial phagocytosis.

3:10 – 3:20 Ben Efron, Yonatan Katz and IIan Lampl

Weizmann Institute of Science

Auditory response to sounds originating from whisking against objects

Integration of information from different sensory modalities is essential for faithful representation of the world.

We studied the implications of active whisking sensation in the auditory system of mice and showed that it can

sense sounds resulting from whiskers touching an object, thus the vibrissa system can be used as an audio-

tactile system. We hypothesized that when mice whisk against objects they produce-audible noise. To test this,

we recorded sounds produced when whiskers actively contact objects. We found that when mice whisk against

certain objects, whisking-contact events produce audible broadband sounds. We then asked if these whisking-

touch induced sounds could elicit response in the auditory system. Towards this goal, we recorded activity in

the primary auditory cortex and in the inferior colliculus. To determine that any response is purely auditory we

severed the infra orbital nerve which conveys information from the whiskers to the CNS. Despite the loss of

tactile sensation, we found cells that responded precisely to whisking-touch events. We also muted the noise

produced from an object and presented the mouse with both the muted and unmuted objects. Although tactilely

identical, contacts made with the unmuted objects elicited a much stronger neuronal response in auditory

neurons. These novel findings are potentially relevant to the ethology of rodents that actively explore their

environment by whisking and for understanding of multi-modal integration.

Moderated by Cornelius Schwarz (Univ Tuebingen)

3:20 – 3:30 Silvana Valtcheva, Habon Issa and Robert C. Froemke

Skirball Institute, New York University School of Medicine

Hypothalamic oxytocin neurons respond to infant vocalizations via

noncanonical auditory pathway

Babies are “sensory traps” for mothers which are highly sensitive to infant needs. We recently showed that

core aspect of maternal behavior, pup retrieval in response to infant vocalizations, is shaped by the interplay

between innate preferences and active learning of auditory cues from pups, facilitated by the neurohormone

oxytocin (OT) (Schiavo, Valtcheva et al., Nature, accepted). Release of OT from hypothalamus might help

the recognition of pup calls but it is unclear how auditory infant stimuli are integrated in OT neurons. Here we

performed in vivo patch-clamp from optically-identified OT neurons in awake maternal mice. OT neurons, but

not other hypothalamic cells, increased their firing rate after pup calls. Using anatomical tracing and slice

physiology, we identified the brain areas (including posterior intralaminar thalamus) relaying acoustic

information to OT neurons. In hypothalamic slices, we mimicked high-frequency thalamic discharge, via

optogenetic stimulation, which led to long-term depression of synaptic inhibition and decreased inhibition to

excitation ratio in OT neurons. Increased firing of OT neurons after pup calls in vivo is likely mediated by

disinhibition. When thalamic projections to hypothalamus were inhibited, maternal mice exhibited longer

latencies to retrieve pups, suggesting that the thalamus-hypothalamus noncanonical auditory pathway may

be a specific circuit for disinhibiting OT neurons, gating OT release, and speeding up maternal behavior.

3:30 – 3:40 Tamura Keita, Esmaeili Vahid, Crochet Sylvain, Petersen Carl.

Brain Mind Institute, Ecole Polytechnique Federale de Lausanne (EPFL)

Cortical signal flow during sensorimotor transformation in a whisker

detection and delayed lick task

We use sensory cues to make appropriate behavior, but the circuit mechanisms converting a sensory input to

a motor output remain to be elucidated. Here, we performed wide-field Ca2+ imaging in mice performing a

task where mice detected a brief whisker deflection, and reported it by licking a spout after a 1-s delay period

that ended with an auditory stimulus. We trained transgenic mice expressing RCaMP in cortical pyramidal

neurons, and longitudinally observed their activity across learning. In correct hit trials, the whisker cue evoked

activation in whisker S1 cortex within 30 ms, followed by whisker S2 within 40 ms, whisker M1/M2, parietal

and retrosplenial cortices within 60 ms, with several areas showing enhancement in expert compared to

novice mice. In striking contrast, S1 and M1 cortices for tongue/jaw (tjS1/M1) in experts sharply decreased

the activity within 80 ms, which might reflect suppression of premature licks. Along the delay period,

sustained activity became prominent in M2 cortices for whisker as well as tongue/jaw in experts. After

auditory-evoked response in A1 cortex, tjS1/M1 developed a prominent activity reflecting the licking. These

results suggest that whisker sensory information was initially rapidly distributed across cortex and then

converged on the M2 cortices for preparing a motor command. Combining optogenetic manipulations

together with wide-field imaging will further reveal how cortico-cortical connections change to produce a

specific behavior.

3:40 – 3:50 Ewoud Schmidt, Hanzhi Teresa Zhao, Jung Park, Jacob Dahan, Chris Rodgers,

Elizabeth Hillman, Randy Bruno, Franck Polleux

Zuckerman Institute, Kavli Institute for Brain Science, Columbia University

A human-specific modifier of cortical circuit connectivity and function improves

sensory discrimination in mice

Human cortical pyramidal neurons (PNs) are characterized by increased synaptic density and prolonged

synaptic maturation. These features are thought to be critical for human cognition by increasing neuronal

connectivity, including increased feedforward and feedback connectivity. However, we lack insight into how this

connectivity emerged and how it contributes to human cognition. We identified a human gene, SRGAP2C, that

in mouse cortical PNs induces traits in synaptic development similar to those found in humans. Using a novel

implementation of monosynaptic tracing to map inputs from the whole brain onto layer 2/3 PNs in the barrel

cortex, we discovered that SRGAP2C selectively increases cortical feedforward and feedback connectivity. In

vivo 2-photon Ca2+ imaging in the barrel cortex revealed that SRGAP2C improves sensory coding of layer 2/3

PNs by increasing stimulus response probability, while reducing overall spontaneous activity. We examined

whether these structural and functional connectivity changes affect behavior by using a novel two-alternative

forced choice texture discrimination task. We tested the ability of humanized SRGAP2C mice to discriminate

between two different rough textures using their whiskers and found that SRGAP2C mice display an increased

ability to learn this cortex-dependent task. We propose that the emergence of SRGAP2C critically changed

cortical circuit connectivity and function, and provided a key evolutionary step towards improved cognition.

Moderated by Garrett Stanley (Georgia Tech)

3:50 – 4:00 Yasir Gallero-Salas, Shuting Han, Yaroslav Sych, Fabian F. Voigt, Balazs Laurenczy,

Ariel Gilad*, Fritjof Helmchen*

Brain Research Institute, University of Zurich, Neuroscience Center Zurich, Hebrew

University Medical School. *Co-senior authorship

Sensory and behavioral components of neocortical signal flow in tactile

and auditory discrimination tasks with short-term memory

In neocortex, each sensory modality engages distinct primary and secondary areas that route information

further to association areas. Where signal flow may converge for maintaining information in short-term memory

and how behavior may influence signal routing remain open questions. Using wide-field calcium imaging, we

compared cortex-wide neuronal activity in layer 2/3 for mice trained in auditory and whisker-based tactile

discrimination tasks with delayed response. In both tasks, mice were either active or passive during stimulus

presentation, engaging in body movements or sitting quietly. Irrespective of behavioral strategy, auditory and

tactile stimulation activated spatially segregated subdivisions of posterior parietal cortex (areas A and RL,

respectively) necessary for task completion and representing stimulus-related information. In the subsequent

delay period, in contrast, behavioral strategy rather than sensory modality determined where short-term

memory was located: frontomedially in active trials and posterolaterally in passive trials. Our results suggest

behavior-dependent routing of sensory-driven cortical information flow from modality-specific PPC subdivisions

to higher association areas.

4:00 – 4:10 Cameron Condylis, Abed Ghanbari, Karina Bistrong, Zizhen Yao, Thuc Nghi Nguyen,

Hongkui Zeng, Bosiljka Tasic, Jerry L. Chen

Boston University, Allen Institute for Brain Science

Multiplexed functional and transcriptional readout of mouse primary

somatosensory cortex during behavior

Information processing in the neocortex is carried out by neuronal circuits composed of different cell types.

Recent census of the neocortex using single cell transcriptomic profiling has uncovered more than 100 putative

cell types which subdivide major classes of excitatory and inhibitory neurons into distinct subclasses. The

extent to which this molecular classification predicts distinct functional roles during behavior is unclear. Here,

we combined population recordings using two-photon calcium imaging with spatial transcriptomics using

multiplexed fluorescent in situ hybridization to achieve dense functional and molecular readout of cortical

circuits during behavior. We characterized task-related responses across major transcriptomic neuronal

subclasses and types in layer 2/3 of primary somatosensory cortex as mice performed a tactile working

memory task. Distinct task responses were observed in novel excitatory cell types and inhibitory subclasses.

Simultaneous recordings across the population reveal functional connectivity motifs between specific

subclasses and types that either vary or persist across different task-defined networks. Our results reveal that

as neurons are segregated into increasingly discrete molecular types, their task-related properties continue to

differentiate. This broadens our understanding of how neocortical neurons are defined by their transcriptomic

profile, are composed into circuits, and participate in computations during behavior.

4:10 – 4:20 Christian L. Ebbesen, Robert Froemke

New York University

Automatic tracking of mouse social posture dynamics by 3D videography, deep

learning and GPU-accelerated robust optimization

Social interactions powerfully impact both the brain and the body, but high-resolution descriptions of these

important physical interactions are lacking. Currently, most studies of social behavior rely on labor-intensive

methods such as manual annotation of individual video frames. These methods are susceptible to

experimenter bias and have limited throughput. To understand the neural circuits underlying social behavior,

scalable and objective tracking methods are needed. We present a hardware/software system that combines

3D videography, deep learning, physical modeling and GPU-accelerated robust optimization. Our system is

capable of fully automatic multi-animal tracking during naturalistic social interactions and allows for

simultaneous electro-physiological recordings. We capture the posture dynamics of multiple unmarked mice

with high spatial (∼2 mm) and temporal precision (60 frames/s). This method is based on inexpensive

consumer cameras and is implemented in python, making our method cheap and straightforward to adopt and

customize for studies of neurobiology and animal behavior. FUNDING: This work was supported by The Novo

Nordisk Foundation (C.L.E.), the BRAIN Initiative (NS107616 to R.C.F.) and a Howard Hughes Medical

Institute Faculty Scholarship (R.C.F.).

4:20 – 4:30 Jim McBurney-Lin, Yina Sun, Lucas S. Tortorelli, Quynh Anh Nguyen, Sachiko Haga-

Yamanaka, Hongdian Yan

University of California, Riverside

Bidirectional pharmacological perturbations of the noradrenergic system

differentially affect tactile detection

The brain neuromodulatory systems heavily influence behavioral and cognitive processes. Previous work has

shown that norepinephrine (NE), a classic neuromodulator mainly derived from the locus coeruleus (LC),

enhances neuronal responses to sensory stimuli. However, the role of the LC-NE system in modulating

perceptual task performance is not well understood. In addition, systemic perturbation of NE signaling has

often been proposed to specifically target the LC in functional studies, yet the assumption that localized

(specific) and systemic (nonspecific) perturbations of LC-NE have the same behavioral impact remains largely

untested. In this study, we trained mice to perform a head-fixed, quantitative tactile detection task, and

administered an α2 adrenergic receptor agonist or antagonist to pharmacologically down- or up-regulate LC-

NE activity, respectively. We addressed the outstanding question of how bidirectional perturbations of LC-NE

activity affect tactile detection, and tested whether localized and systemic drug treatments exert the same

behavioral effects. This work was supported by UCR startup, UC Regents’ Faculty Fellowship, Klingenstein-

Simons Fellowship Awards in Neuroscience, and National Institute of Neurological Disorders and Stroke

1R01NS107355 and 1R01NS112200.

4:30 – 6:00 Virtual Poster Session

Friday, October 23 (All times EDT)

11:30 – 12:00 Check-in (Please login closer to 11:30 as you must be admitted to the meeting

12:00 – 12:50 Keynote 2: Nadine Gogolla, Introduced by Robert Sachdev

Max Planck Institute, Martinsried

Facial expressions and their neuronal correlates in mice

Unravelling the neuronal underpinnings of sensory perception, valence attribution and emotion state requires

sensitive readouts of subjective experiences. In my talk, I will present recent evidence from my lab showing

that mice exhibit a diverse repertoire of stereotyped and highly experience-specific facial expressions. Using

machine-learning algorithms, we were able to describe mouse facial expressions objectively and quantitatively

at millisecond time scales. We were thus able to decode intensity, value and persistence of the subjective

experience in individual mice and classify facial expressions into emotion-like categories, which share

fundamental properties of basic emotions in humans. Combining facial expression analysis with two-photon

calcium imaging, we identified single neurons whose activity closely correlated with specific facial expressions

in the insular cortex, a brain region implicated in subjective affective experiences in humans.

12:50 – 1:00 Coffee Break (randomized break-out rooms)

Session 3: Reorganization of neuronal representations

1:00 – 1:10 Moderator introduction: Dan Feldman

University of California, Berkeley

1:10 – 1:40 Andrew Hires

University of Southern California

Behavioral and neuronal bases of tactile shape discrimination learning in

head-fixed mice

Neural representations of the external world are built from patterns of sensory input. In the cortex, these

representations can be surprisingly dynamic, shifting over time and across learning. We investigated this

reorganization using volumetric two-photon imaging of primary somatosensory cortex in mice learning to

discriminate simple shapes with their whiskers. I will present how the representations of shape are distributed

across cortical layers, how they are assembled from sensory input features, and how training increases the

importance of task-relevant sensory features, specifically enhancing discrimination of trained examples. These

results suggest mechanisms by which cortical reorganization allows flexible improvement in task performance

while maintaining perceptual stability.

1:40 – 2:10 Simon Peron

New York University

Barrel cortex dynamics during optical microstimulation task training

During the lifetime of an animal, sensory cortex often experiences repeated presentation of a novel input

pattern. Theoretical studies of cortical plasticity have predicted that repeated presentation of novel input

should drive a range of changes in primary sensory cortex, but plasticity at other processing stages

complicates interpretation of existing experimental data. Here, we use direct optogenetic stimulation of layer

(L) 2/3 pyramidal neurons in primary vibrissal somatosensory cortex (vS1) of mice as they learn to report

whether the number of light pulses is below or above a threshold. Consequently, vS1 L2/3 experiences a

consistent, novel neural activity pattern that the animal must attend to. We use two-photon imaging in

transgenic mice expressing GCaMP6s to track vS1 neural dynamics as mice learn this task. We find that the

directly driven population sparsens rapidly over the course of learning. At the same time, we find a small

subset of neurons whose activity increases over the first few days and remains stable throughout the

remainder of training. This is consistent with theoretical models of repeated cortical stimulation showing

increased feedback inhibition for highly responsive neurons, combined with tuning-specific increases in

recurrent excitation.

2:10 – 2:40 Carsen Stringer

Janelia Research Campus

A neural atlas of multi-dimensional behavioral representations

Neuronal populations in sensory cortex produce variable responses to sensory stimuli and exhibit intricate

spontaneous activity even without external sensory input. Recording more than 10,000 neurons in mouse

visual cortex, we observed that spontaneous activity reliably encoded a high-dimensional latent state, which

was partially related to the mouse’s ongoing behavior and was represented not just in visual cortex but also

across the forebrain. Sensory inputs did not interrupt this ongoing signal but added onto it a representation of

external stimuli in orthogonal dimensions. Thus, visual cortical population activity, despite its apparently noisy

structure, reliably encodes an orthogonal fusion of sensory and multidimensional behavioral information. It is

unknown whether different mice represent this behavioral information in their brains in similar ways. Therefore,

we are characterizing the similarity of neural-behavioral representations across mice by mapping mouse

behavioral movements into a common coordinate framework.

2:40 – 3:00 Discussion

3:00 – 3:20 Coffee Break

Short Platform Talks 3 (10 min including questions)

Moderated by Robert Sachdev (Humboldt University)

3:20 – 3:30 Nathaniel C. Wright, Peter Y. Borden, Yi Juin Liew, Michael F. Bolus, William A. Stoy,

Craig R. Forest, Garrett B. Stanley

Georgia Institute of Technology, Emory University

Rapid sensory adaptation in the mouse thalamocortical circuit during

wakefulness, and the relative contribution of thalamic state

Rapid sensory adaptation is ubiquitous across sensory systems, but the mechanistic basis is poorly

understood. A wide range of (primarily in vitro and anesthetized) studies have uncovered rapid adaptation

effects in the thalamocortical circuit, which may underlie adaptive changes in perception. Yet it is unclear

whether the circuit can be appreciably adapted during wakefulness, when baseline firing rates are higher, or

what role various candidate mechanisms play. To address these unknowns, we recorded spiking activity in

VPm and S1 of the awake mouse, and quantified responses to punctate whisker deflections delivered either

in isolation or embedded in adapting sensory white noise. We found that cortical sensory responses were

indeed adapted by sensory white noise; putative excitatory firing was profoundly adapted, and inhibitory firing

only modestly adapted. Further optogenetic manipulation experiments and network modeling suggest this

largely reflects adaptive changes in thalamic “state” (rate, tonic/burst firing, and synchrony) and robust

feedforward inhibition, with little contribution from synaptic depression. Taken together, these results suggest

that ethologically-relevant changes in thalamic state during normal behavior have major impacts for cortical

sensory representations and perception. Funding: NIH BRAIN NINDS-R01NS104928 (Stanley), NIMH-

U01MH106027 (Stanley, Forest), NIH NINDS F31NS098691 (Borden), NIH R01EY023173 (Forest), NSF

GRF (Stoy)

3:30 – 3:40 Jan Jabłonka, Marcin Kaźmierczak, Maria Sadowska, Władysław Średniawa,

Paulina Urban

University of Warsaw

Interhemispheric interactions participate in the cortical plasticity

The two hemispheres of the brain are commonly treated as independent structures when peripheral or even

cortical manipulations are applied to one of them. We present results suggesting that cortical, experience-

dependent plasticity (ExDP) is not a unilateral, independent process but rather a combination of a variety of

interactions between the two hemispheres. We mapped metabolic brain activity with 2-[14C] deoxyglucose

(2DG) following ExDP induction by unilateral, partial whiskers deprivation, which resulted in the band of cortical

representation widening by ~45%. Here we show that the width of 2DG visualised representation is much

smaller (~20%) when unilateral stimulation of the spared whiskers is applied than following bilateral

stimulation. The Kernel Electrical Source Imaging (kCSD) was performed for current flow reconstruction from

electrocorticograms (ECoGs) registered across the rows of whiskers representations. The width of sinks and

sources were measured. Both the metabolic and kCSD visualisation of the cortical activity mappings confirm

the inconsistent response to the uni- vs bilateral stimulation in deprived animals. The results suggested that

ExDP that leads to cortical maps rearrangement depends on the contralateral hemisphere as well. The

response observed in 2DG brain mapping in deprived animals after canonically performed, synchronous

bilateral whiskers stimulation is therefore composed of at least two separately activated plasticity mechanisms.

3:40 – 3:50 Jason M. Guest, Arco Bast, Marcel Oberlaender

Max Planck Society, Research Center caesar

Thalamus gates top-down modulation of cortical output

How can pyramidal tract neurons integrate sensory information from thalamocortical and intracortical

populations with contextual information from top-down corticocortical pathways? Based on recently reported

and ongoing work in my lab, I will we show how input from primary thalamus enables pyramidal tract neurons

to integrate the current state of their respective local and long-range input populations with stimulus

information. Sensory-evoked thalamocortical gating of cortical output may thereby provide subcortical circuits

with an integrated efference copy that reflects sensory input and context. Funding was provided from the

Center of Advanced European Studies and Research, the European Research Council (grant agreement

633428), the German Federal Ministry of Education and Research (grants BMBF/FKZ 01GQ1002 and

01IS18052), and the Deutsche Forschungsgemeinschaft (SFB 1089 and SPP 2041).

Moderated by Kate Hong (Carnegie Mellon University)

3:50 – 4:00 Mikkel Vestergaard*, M. Carta*, J.F.A. Poulet. *Co-first author

Max-Delbrück Center (MDC), Charité-Universitätsmedizin Berlin, Interdisciplinary

Institute for Neuroscience, University of Bordeaux, CNRS

The cellular coding of temperature in the mammalian cortex

Thermosensation is a key sense required for object identification during haptic exploration, accurate

monitoring of environmental temperature and the perception of pain. The neural encoding of temperature has

been addressed in the sensory periphery, but, unlike almost all other sensory modalities, a central cortical

area for temperature processing has not been identified. It has been suggested that insular cortex and

primary somatosensory cortex (S1) play a role, however, using calcium imaging in awake mice, we show that

S1 only responds to skin cooling but not warming. In contrast, a posterior region of insular cortex (pIC)

contains a somatotopic representation of warm and cool with heterogeneously arranged, thermally-tuned

cells with distinct coding properties. Furthermore, reversible optogenetic manipulations show strong impact of

pIC on thermal perception. Together, this work locates a thermal cortex and identifies fundamental encoding

schemes of temperature in central circuits. This work was supported by the European Research Council

(ERC-2015-CoG-682422, J.F.A.P.), the European Union (3x3Dimaging 323945, J.F.A.P.), the Deutsche

Forschungsgemeinschaft (DFG, FOR 2143, J.F.A.P., SFB 1315, J.F.A.P.), the Helmholtz Society (J.F.A.P.),

the Centre National de la Recherche Scientifique (CNRS) (M.C.) and the Independent Research Fund

Denmark (M.V.).

4:00 – 4:10 Clément Brunner*, Micheline Grillet*, Arnau Sans-Dublanc, Karl Farrow, Théo

Lambert, Emilie Macé, Gabriel Montaldo & Alan Urban. *Authors contributed

equally.

Neuro-Electronics Research Flanders, VIB, Imec, KU Leuven, Max Planck Institute of

Neurobiology

A platform for brain-wide functional ultrasound imaging and analysis of

circuit dynamics in behaving mice

Imaging of large-scale circuit dynamics is crucial to gain a better understanding of brain function, but most

techniques have a limited depth of field. Here we describe vfUSI, a platform for brain-wide volumetric

functional ultrasound imaging of hemodynamic activity in awake head-fixed mice. We combined high-

frequency 1024-channel 2D-array transducer with advanced multiplexing and high-performance computing

for real-time 3D Power Doppler imaging at high spatiotemporal resolution (220x280x175-µm3 voxel size, up

to 6 Hz). In addition, we developed a standardized software pipeline for registration and segmentation based

on the Allen Mouse Common Coordinate Framework, allowing for temporal analysis in 268 individual brain

regions. We demonstrate the high sensitivity of vfUSI in multiple experimental situations where stimulus-

evoked activity can be recorded using a minimal number of trials. We also mapped neural circuits in vivo

across the whole brain during optogenetic activation of specific cell-types. Moreover, we revealed the

sequential activation of sensory-motor regions during a grasping water droplet task. vfUSI will become a key

neuroimaging technology because it combines ease of use, reliability, and affordability. Funding This work

was supported by grants from the Leducq Foundation (15CVD02), from FWO (MEDI-RESCU2-AKUL/17/049,

G091719N, and 1197818N), from VIB TechWatch (fUSI-MICE) and from internal NERF TechDev fund (3D-

fUSI project).

4:10 – 4:20 Yu Ding and Yuri Vlasov

University of Illinois at Urbana-Champaign

High-frequency whisker vibrations above 1KHz - are they relevant to perception?

We performed a systematic study of high -frequency vibrations of rodents whiskers using acoustical methods.

We identified a regular series of higher order modes (up to 30) spanning frequencies up to 10KHz. While

interaction of a whisker with a pole excites mostly lower-order modes (80% of total energy), interaction with a

textured surface redistributes over 60% of these vibrational energy to modes higher than 1KHz. Moreover,

these higher order modes exhibit up to 15X smaller damping ratio and are propagating 4X faster, that makes

them the fastest and the most powerful messengers of shock-wave events during whisker scan over textured

surfaces. Based on these observations we propose a hypothesis of mechanical transduction that can explain

observation of ultrafast microseconds-scale jitter in response of primary afferents to fast whisker stimulations.

4:20 – 4:30 Wrap-up discussion & Poll

4:30 – 6:00 Virtual Poster Session

ADJOURN

Presenter Title Present W Present T Present F Email

Ehud Ahissar What happens when you free the head X X ehud.ahissar@weizmann.ac.il

Alicia Barrientos Examining the relationship between microglia and the perineuronal net during a critical period of somatosensory cortex development X X abarrientos@gradcenter.cuny.edu

Sam Benezra Associative learning enhances sensory representations of layer 5 apical dendrites in primary somatosensory cortex X X sb4096@columbia.edu

Flore Boscher Cortical states during whisking in awake and sleeping mice X X flore.marie.boscher@gmail.com

Thomas Burnett A Barrel-less Somatosensory Cortex: Ferret S1 X X tburnet7@jhmi.edu

Giuseppe Cataldo Functionality of Patterning: Electrophysiological Analysis of the Principle Sensory Nucleus in Prrxl1 Knockout and Barrelless Mice X X mariolz@yahoo.com

Trishala Chari A novel behavioral assay to investigate social touch deficits in mouse models of autism X X tchari2018@g.ucla.edu

Suma Chinta Sensorimotor integration in the superior colliculus during whisker-guided orienting behavior X X chintas@purdue.edu

Yu Ding High-frequency whisker vibrations above 1KHz - are they relevant to perception? X X yud2@illinois.edu

Grzegorz Dobrzański Layer IV (L4) somatostatin interneurons and functional plasticity of the barrel cortex. X X g.dobrzanski@nencki.edu.pl

Arash Fassihi Direct modulation of the perceived duration through optogenetic manipulation of somatosensory cortex X X arfassihi@gmail.com

Ana Inacio Brain-wide neural networks of movement-encoding neurons in the primary somatosensory cortex X X ana.inacio@nih.gov

Daniel Kato Effects of Learning and Experience on Multisensory Integration in Mouse Primary Somatosensory Cortex X X dk2643@columbia.edu

Yonatan Katz Cross-whisker adaptation of neurons in layer 2/3 of the rat barrel cortex X X yon.katz@gmail.com

Jinho Kim Behavioral and neural bases of tactile shape discrimination learning in head-fixed mice X X jinho@usc.edu

Sarah Lutchman Alterations in the Perineuronal Nets, Microglial Cells, and Novel Object Discrimination in Prenatally Restricted Mice X X sarah.lutchman16@qmail.cuny.edu

Eduard Maier An isomorphic three-dimensional cortical model of the pig rostrum X X eduard.maier@bccn-berlin.de

Phillip Maire Automatic whisker contact classification using a convolutional neural network X X maire@usc.edu

Krista Marrero Effects of Prestimulus Activity on Performance of a Selective Detection Task X X kmarr006@ucr.edu

Katherine Matho Genetic dissection of glutamatergic neuron subpopulations and developmental trajectories in the cerebral cortex X X Kmatho@cshl.edu

Hisham Mohammed A Modified Behavioral Test of Forelimb Dexterity in Mice X X Hisham.sys@gmail.com

Aurelie Pala Integration of bilateral tactile signals in somatosensory cortices of the awake mouse X X aurelie.pala@gmail.com

William Olson Jaw movement-modulated activity of sensory neurons in the mesencephlic trigeminal nucleus during a directional licking task X X wolson6@johnshopkins.edu

Hyein Park Cortical circuits unifying bilateral space X X park1223@purdue.edu

Georgia Pierce Not-so-sensory activity in the posterior medial nucleus of the thalamus X X gmp2139@columbia.edu

Rikki Rabinovich Learning-related changes in activity of superficial layer cells in barrel cortex X X rjr2153@columbia.edu

Deepa Ramamurthy Recent trial history cues attentional selection of whisker stimuli in mice X X dlramamurthy@berkeley.edu

Cindy Ritter An isomorphic three-dimensional cortical model of the pig rostrum X X cindy.ritter@bccn-berlin.de

Chris Rodgers Behavioral strategies and neural representations for shape discrimination X X ccr2137@columbia.edu

Isis Wyche Whisker inertia contributes to self-motion encoding in the mouse whisker system X X iwyche1@jhmi.edu

Poster Session Schedule

BARRELS XXXIII POSTER ABSTRACTS

Ehud Ahissar, Tess Oram, Alon Tenzer, Inbar Saraf-Sinik, Ofer Yizhar

Weizmann Institute of Science

Awakening the POm: What happens when you free the head

Headfixed rats and mice are dramatically restrained in their behavior. Previous studies showed that the paralemniscal

nucleus of the thalamus, the POm, is relatively quiet in this condition. We show that when the mouse is free to move POm

gets back to life, exhibiting robust coding of both whisker and head motion. Optogenetic stimulations further suggest that

both the POm and VPM take active part in the motor-sensory-motor loop controlling head motion.

Alicia C. Barrientos (1), Sara Mroziuk (2), Arya Lahijani (2) and Joshua C. Brumberg,(1,2,3)

[1] The Graduate Center, CUNY – Behavioral and Cognitive Neuroscience PhD program; [2] Queens College, CUNY –

Dept. of Psychology; [3] Queens College, CUNY – Dept. of Biology

Examining the relationship between microglia and the perineuronal net during a critical period of somatosensory

cortex development

Sensory deprivation (SD) during the critical period of development results in behavioral and cognitive abnormalities in

mammals. Previous studies from the laboratory demonstrated that SD via whisker trimming leads to activation of microglia

(MG) in the primary somatosensory cortex (S1) and a reduction of perineuronal nets (PNNs). The current study utilizes

SD in conjunction with pharmacological manipulations to activate or inhibit MG throughout a developmental critical period

within S1. Mice were injected with either saline (control), minocycline (MG inhibitor) or lipopolysaccharide (inflammatory

agent) until post-natal day 30 while another cohort additionally underwent SD. We hypothesized that SD and LPS will

activate MG, which in turn will impact PNN density and integrity. Preliminary data shows that SD impacts MG across all

injection treatments, while also resulting in qualitative changes to the PNN. This study is among the first to show

correlative evidence that MG may be shaping the PNN. Funding: This work is supported by NIH grant NIGMS

1SC3GM122657

Sam Benezra, Elizabeth Hillman, Randy Bruno

Zuckerman Institute, Columbia University

Associative learning enhances sensory representations of layer 5 apical dendrites in primary somatosensory

cortex

Cortical layer 1, comprised mainly of apical tuft dendrites of pyramidal neurons, may be a key site of associative learning.

We investigated the effects of associative learning on dendritic activity in layer 1 of primary somatosensory cortex by

devising a simplified awake head-fixed mouse conditioning paradigm. Air puffs directed at the whiskers are aimed in either

of two directions: rostrocaudal (backward) or ventrodorsal (upward). One of the directions is paired with a water reward

and thus corresponds to a conditioned stimulus (CS+). No reward is given during puffing of the whiskers in the other

direction (CS-). Using both two-photon microscopy and a new high-speed volumetric imaging method called SCAPE, we

longitudinally tracked calcium activity in apical dendrites as mice learned to associate the CS+ with reward. We found that

in naïve animals, apical responses are largely unselective for conditioned stimuli, but become highly selective for either

the CS+ or CS- as behavioral performance improves. This enhanced sensory representation persists even after rewards

are removed on the last session. Our results demonstrate that classical conditioning has a long lasting effect on the

recruitment of apical dendrites by behaviorally relevant stimuli, and provide an avenue for further investigation of cellular

and circuit mechanisms underlying plasticity induced by perceptual experience and reinforcement.

Flore Boscher and Nadia Urbain

Centre de Recherche en Neurosciences de Lyon, INSERM U1028 – CNRS UMR5292, UCB-Lyon1 University

Cortical states during whisking in awake and sleeping mice

A striking feature of the EEG observed during rapid eye movements sleep (REM) is its close resemblance to the EEG

patterns observed during the fundamentally different cognitive state of wakefulness. Investigating how sensory inputs are

processed at the cortical level throughout the sleep-wake cycle is a crucial step towards a better understanding of the

function of sleep. Therefore, we developed a technical approach to perform local field potential recordings in the mouse

primary somatosensory cortex (S1-LFP) combined with the monitoring of the EEG and the electromyogram and video-

tracking of whisker movements. Active cortical states were characterized by small-amplitude fast LFP and EEG

fluctuations, with or without whisking, while quiet wakefulness was characterized by significant larger-amplitude

fluctuations in the 1-6 Hz frequency range. Similarly, we observed that the 1-6 Hz spectral power of S1-LFP recorded in

REM was significantly higher during periods between whisking bouts (REM-Quiet) than during whisking (REM-Whisking).

At the EEG level, we did not observe such a change in low frequency spectral power across REM episodes, but a shift to

higher frequencies in the EEG Theta band in REM-Whisking compared with REM-Quiet, suggesting that cortical state

BARRELS XXXIII POSTER ABSTRACTS

changes during REM-Whisking is not restricted to S1 cortex, but might involve other brain areas. ANR Grant 17-CE16-

0024. French Ministry fellowship.

Thomas Burnett, Kristina Nielsen, Daniel O'Connor

Johns Hopkins University School of Medicine

A Barrel-less Somatosensory Cortex: Ferret S1

Mammals’ vibrissae hold great importance in navigation and object exploration, but of the thousands of mammal species,

relatively few possess a barrel cortex. How then may whisker tactile inputs be represented? We explore this question in

the non-whisking ferret, Mustela putorius furo, an established neurodevelopmental and sensory model. Through

electrophysiology and histology, we show ferrets definitively lack a barrel cortex, but possess an expanded whisker

representation. Whiskers are somatotopically represented, with a reversal akin to other carnivores. Interestingly, we find

neurons responsive to single whisker and multi-whisker deflections, a potential means of motion integration similar to

barrel cortex. We also present preliminary data suggesting a behavioral deficit from the removal of whiskers. We hope

these findings may provide a new avenue to exploring whisker-mediated behavior and active sensation.

Trishala Chari 1,3; Zoë Dobler 1,3; Carlos Portera-Cailliau 1,2

[1] Dept. of Neurology; [2] Dept. of Neurobiology; [3] Neuroscience Interdepartmental Program David Geffen School of

Medicine UCLA

A novel behavioral assay to investigate social touch deficits in mouse models of autism

We are investigating whether social avoidance in individuals with autism is due to hypersensitivity to social touch using

the genetic Fmr1-/- model of Fragile X Syndrome and the maternal immune activation (MIA) autism model. We designed a

novel assay to investigate the behavioral responses to social touch in mice. A test mouse, head-fixed but free to run on an

air-suspended polystyrene ball, is allowed to voluntarily (whisker-whisker) or forcibly (snout-snout) interact with a stranger

mouse that is head-fixed on a moving platform. We recorded high-speed videos to analyze mouse behavior and pupil size

using MATLAB and DeepLabCut. Repeated bouts of voluntary interactions led to pupil constriction in healthy controls but

not in Fmr1-/- or MIA mice, suggesting persistent hyperarousal. In contrast, all groups showed similar degrees of pupil

constriction to bouts of forced contact. Autism model mice displayed prominent avoidance behaviors, spending more time

running away from the stranger mouse during forced and voluntary interactions compared to healthy controls.

Interestingly, we observed sex differences, with Fmr1-/- and MIA females displaying greater avoidance than males. Both

voluntary and forced touch interactions resulted in facial features representing an aversive emotional state, particularly in

Fmr1-/- mice. This novel assay is a promising tool for investigating social touch deficits in autism mouse models. Funding:

R01 HD054453 (NICHD), R01 NS117597 (NINDS).

Suma Chinta and Scott Pluta

Purdue University, Department of Biology

Sensorimotor integration in the superior colliculus during whisker-guided orienting behavior

Spatial attention involves the parallel integration of multiple, disparately organized neural circuits. These disparate circuits

ultimately converge onto the midbrain superior colliculus (SC), where individual neurons encode the location of stimuli,

sustain working memory and initiate overt movements. However, the role of the SC in active, somatosensory-guided

movements is largely unknown. Since mice do not track objects by moving their eyes, somatosensory-guided whisker

movements provide a unique opportunity for greatly advancing our mechanistic understanding of overt spatial attention.

To probe this topic, we recorded spiking from the SC while mice used their whiskers to explore the surface of a

dynamically moving object. Mice dynamically optimized their whisking set-point and amplitude to track object movement.

Many neurons in the SC responded to surface movement with an increase in spiking, while others decreased their activity,

in a location-specific manner. Overall, we observed a clear preference for a particular trajectory of surface movement.

Trajectory tuning was consistent with neuron-specific preferences for whisker curvature and phase during touch. Spiking

in a subset of neurons located in the deepest, motor layer of the SC predicted whisk amplitude. Overall, these data help

establish the rodent whisker system as a valuable model for dissecting the neural circuits underlying overt spatial

attention.

Dobrzanski G, Lukomska A, Zakrzewska R, Kanigowski D, Kossut M

Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland

Layer IV (L4) somatostatin interneurons and functional plasticity of the barrel cortex.

Enlargement of functional representation of whiskers can be induced in two experimental models: sensory deprivation

sparing selected whiskers and fear learning where stimulation of selected whiskers is the conditioned stimulus. The plastic

BARRELS XXXIII POSTER ABSTRACTS

change of cortical representation of cognate whiskers is detected with [14C]-2-deoxyglucose (2DG) autoradiography

mainly in barrel cortex L4. Such plasticity was linked to the action of somatostatin interneurons (SOM-INs). We examined

how formation of the plastic change is affected by modulation of L4 SOM-INs activity. Using cell-specific transduction and

layer-targeted injections we introduced DREADDs to SOM-INs with cell bodies localized mainly in L4 and modulated their

activity in both experimental models. After procedure completion, selected whiskers were stimulated and 2DG mapping

was performed. L4 SOM-INs inhibition during learning, selectively in representation of the conditioned row of whiskers

prevents plasticity formation. SOM-INs blockade in deprived barrels (but not in spared one) adjacent to the spared one,

decreases sensory deprivation-induced plasticity of spared whisker representation. L4 SOM-INs may monitor and adjust

thalamic inputs-dependent neuronal activity in L4. Under important environmental circumstances may support conveying

information about salient stimuli or brain states across the cortical column, contributing to plasticity formation. Funding:

Polish National Science Centre Grant to GD (2017/27/N/NZ4/02639)

Arash Fassihi (2), Sebastian Reinartz (1), Alessandro Toso (1), Francesca Pulecchi (1) , Mathew E. Diamond (1)

[1] International School for Advanced Studies, Trieste, Italy; [2] Department of Physics, Section of Neurobiology,

University of California, San Diego

Direct modulation of the perceived duration through optogenetic manipulation of somatosensory cortex

In humans and rats, when subjects judged the duration of a vibration applied to the fingertip (human) or whiskers (rat),

increasing stimulus amplitude led to increased perceived duration. Symmetrically, increasing vibration duration led to

increasing perceived intensity. We hypothesized that this mechanism is the leaky integration of sensory input. We first

asked whether the amplitude-dependent bias in the perceived duration can be replicated by integrating the vibrissal

somatosensory cortex (vS1) activity. We recorded vibration-evoked neuronal activity from the vS1 of awake, behaving

rats. We then inserted the spiking activity as the sensory input into the leaky integrator model and could generate

neurometric functions that replicated rats' actual psychophysical functions. Second, we confirmed by targeted optogenetic

manipulation that the amplitude-dependent bias is originated within vS1. Finally, we show that animals' choice bias could

be predicted by leaky integration of the optogenetic modulation activity in vS1.

Ana R Inacio (1), Francisco Pereira (2), Charles R Gerfen (3), and Soohyun Lee (1)

[1] Unit on Functional Neural Circuits, [2] Machine Learning Team, [3] Section on Neuroanatomy, National Institute of

Mental Health, National Institutes of Health

Brain-wide neural networks of movement-encoding neurons in the primary somatosensory cortex

Principal neurons in the primary sensory cortices exhibit heterogeneous patterns of activity, not only in response to

sensory stimuli but also, during spontaneous movements. Yet, how these heterogeneous, behavioral state-dependent

patterns of activity arise is largely unknown. Longitudinal two-photon calcium imaging uncovered a remarkably stable

correlation between the activity of principal neurons in layers II/III of primary somatosensory cortex and spontaneous

movements. This population activity could reliably predict spontaneous movements, but with a subset of neurons

accounting for most of the prediction accuracy. The activity of movement-encoding neurons cannot be explained by

sensory feedback, as paralysis of the contralateral whisker pad did not disrupt correlation with ipsilateral whisker

movements and locomotion. During pharmacological blockade of neuromodulators, the activity levels were altered, but the

correlation of neuronal activity with spontaneous movements was largely maintained. By contrast, glutamatergic

transmission blockers nearly abolished this correlation. Single cell-initiated monosynaptic retrograde tracing and whole-

brain presynaptic network analysis revealed that movement-encoding neurons receive characteristic subcortical inputs.

Our study provides a connectivity rule that supports the representation of spontaneous movements in the primary

somatosensory cortex. Funding: NIH Intramural Research Program.

Daniel D. Kato, Randy M. Bruno

Zuckerman Institute, Columbia University

Effects of Learning and Experience on Multisensory Integration in Mouse Primary Somatosensory Cortex

Primary sensory cortical areas have historically been considered uni-sensory, but an emerging body of evidence suggests

that multi-sensory integration (MSI) occurs even in these early stages of cortical information processing. However, the

effect of learning and experience on these early cortical multi-sensory responses remains unclear. To address this

question, we used in vivo 2-photon imaging to measure the activity of layer 2/3 barrel field neurons over the course of

several days during which a tactile stimulus was paired with a specific auditory stimulus, both in a passive and a rewarded

context. We found that a subset of S1 cells nonlinearly integrated auditory and tactile information in an auditory stimulus-

specific manner even in naïve mice, suggesting a role in representing specific conjunctions of sensory features. Pairing a

tactile and an auditory stimulus in a passive setting did not lead to higher trial-averaged responses to the either auditory

stimulus alone or to the conjunctive auditory-tactile stimulus. Performing the same experiment in a rewarded setting led to

BARRELS XXXIII POSTER ABSTRACTS

a non-selective increase in responses to all stimuli. We are currently investigating whether experience causes S1

responses to different auditory-tactile stimulus conjunctions to overlap more (pattern completion) or less (pattern

separation).

Yonatan Katz and Ilan Lampl

Weizmann Institute of Science, Israel

Cross-whisker adaptation of neurons in layer 2/3 of the rat barrel cortex

Neurons in the barrel cortex respond preferentially to stimulation of one principal whisker and weakly to several adjacent

whiskers. Such integration exists already in layer 4, the pivotal recipient layer of thalamic inputs. Previous studies show

that cortical neurons gradually adapt to repeated whisker stimulations and that layer 4 neurons exhibit whisker specific

adaptation, showing no apparent interactions with other whiskers. The aim of this intracellular study was to determine

whether layer 2 /3 cortical cells exhibit whisker specific adaptation. Towards this aim we compared the synaptic response

of neurons to repetitive stimulation of either one of two responsive whiskers or when stimulation of the two whiskers was

interleaved. We found that in most layer 2/3 cells adaptation is whisker specific. These findings indicate that despite the

multi-whisker receptive fields in the cortex, the adaptation process for each whisker is independent of other whiskers,

perhaps allowing high responsiveness in complex environments.

Jinho Kim, Andrew Erskine, Jonathan A. Cheung, Samuel Andrew Hires

Department of Biological Sciences, Section of Neurobiology, University of Southern California

Behavioral and neural bases of tactile shape discrimination learning in head-fixed mice

Tactile three-dimensional shape recognition requires perception of object surface angles. We investigated how object

surface angles are represented in the brain, how this representation is constructed from sensory inputs, and it reorganizes

across learning. Head-fixed mice learned to discriminate object angles by active exploration with one whisker. Calcium

imaging of excitatory neurons in layers 2-4 of barrel cortex revealed maps of object-angle tuning before and after learning.

Three-dimensional whisker tracking demonstrated that the sensory input components that best discriminate angle (vertical

bending and slide distance) also have the greatest influence on object-angle tuning. Despite high turnover in active

ensemble membership across learning, both the population distribution of object-angle tuning preferences and individual

preferences remained stable. Motor strategy and sensory inputs were not changed across learning, but population

response from touch-response neurons better discriminated object angle after learning. These results show how

discrimination training enhances stimulus selectivity in primary somatosensory cortex while maintaining perceptual

stability.

Sarah Lutchman, Kathleen Berta, Joshua C. Brumberg

Queens College, CUNY

Alterations in the Perineuronal Nets, Microglial Cells, and Novel Object Discrimination in Prenatally Restricted

Mice

Inadequate food consumption during pregnancy can negatively impact fetal brain development, which is mediated in part

by perineuronal nets and microglial cells. Perineuronal nets are a neuronal specific form of the extracellular matrix which

envelop the cell bodies and proximal processes of predominantly GABAergic interneurons. As specialized macrophages,

microglia clear dead neurons and other cellular debris to maintain CNS health. To study how low food consumption

impacts offspring, adult female CD-1 mice were placed on a calorically restricted diet before and during pregnancy. Pups

produced from this group were compared to pups born from ad libitum-fed mothers. Perineuronal nets and microglia in

pups were visualized using histochemistry to better understand how maternal caloric restriction impacts offspring brain

development. A novel object paradigm was also conducted in which mice were allowed to explore two objects of the same

texture. Mice that were calorically restricted in utero had significantly fewer perineuronal nets compared to non-restricted

mice. There was also a sex difference with female offspring being more affected by maternal caloric restriction than male

offspring. The microglia of prenatally restricted mice were more ramified compared to non-restricted mice. Prenatally

restricted pups also spent less time engaging with the novel object in the behavioral paradigm compared to the control

pups. Funding: NIGMS SC3GM122657

Phillip Maire, Jonathan Cheung, Jonathan Sy, Samuel Andrew Hires

University of Southern California

Automatic whisker contact classification using a convolutional neural network

Many labs use tasks that involve whisker active touch against thin movable poles to study diverse questions of sensory

and motor coding. Since neurons operate at temporal resolutions of milliseconds, determining precise whisker contact

BARRELS XXXIII POSTER ABSTRACTS

periods is essential. Yet, accurately classifying the precise moment of touch is time-consuming and labor intensive.

Current classification techniques rely on semi-automated curation, infrared beam crossings, or hard coded distance to

object thresholds. All involve substantial tradeoffs in analysis time or accuracy. We propose the use of convolutional

neural networks to fully automate the identification of whisker-object touch periods. We leveraged TensorFlow and the

MobileNetV2 pre-trained base model with added Pooling and Dense layers to make fast, accurate, and automated

classification of single-whisker touch events from 1000fps video. We used a manually curated set of 92,000 touch and

near-touch (< 2mm distance to pole) frames to train our model in ~7 minutes on Google Colab GPUs. Our initial model

achieves classification AUC levels of >0.98 for these challenging frames. We plan to implement data augmentation

approaches to further increase the classification accuracy. We have also created an intuitive pipeline for data-loading,

image curation and output of class prediction probabilities with the goal of making automated whisker-touch classification

easily accessible to all labs working in this experimental paradigm. NINDS grant R01NS102808

Krista Marrero (1), Krithiga Aruljothi (2), Chengchun Gao (3), Edward Zagha (1,2)

[1] Dept of Neuroscience; [2] Dept of Psychology; [3] Dept of Bioengineering; University of California, Riverside

Effects of Prestimulus Activity on Performance of a Selective Detection Task

In the field of sensory detection, most studies focus on sensorimotor processing after a stimulus arrives (post-stimulus).

However, the prestimulus neural activity can also alter stimulus encoding and behavioral outcomes. We wondered what

aspects of prestimulus activity could impact task performance. We trained mice in a selective whisker detection task, in

which they learned to respond to target stimuli in one whisker field and ignore distractor stimuli in the contralateral whisker

field. During expert task performance, we used widefield Ca

imaging to assess prestimulus and post-stimulus neural

activity broadly across frontal and parietal cortices. We find that, indeed, prestimulus activity strongly predicts trial

outcome, with lower activity preceding response trials (hits and false alarms). Interestingly, the activity predictive of trial

outcome does not localize to whisker regions but globally distributes throughout dorsal neocortex. Using principal

component analysis, we then demonstrate that response trials are associated with a distinct and less variable prestimulus

neural state. We interpret these findings as supporting an optimal prestimulus neural state for task performance that

presents globally, affects response to both target and distractor stimuli, and corresponds with a behavioral state. Our

findings emphasize the influence of prestimulus activity on trial outcome and the relationships between global neural

dynamics and behavioral state.

Katherine S. Matho (1), Dhananjay Huilgol (1), William Galbavy (1,4), Gukhan Kim (1), Miao He (1α), Xu An (1), Jiangteng

Lu (1b), Priscilla Wu (1), Daniela J. Di Bella (2), Ashwin S. Shetty (2), Ramesh Palaniswamy (1), Joshua Hatfield (1),

Ricardo Raudales (1,4), Arun Narasimhan (1), Eric Gamache (1), Jesse Levine (1,5), Jason Tucciarone (1,5c), Partha

Mitra (1), Pavel Osten (1), Paola Arlotta (2,3), Z. Josh Huang (1)

[1] Cold Spring Harbor Laboratory, Cold Spring Harbor; [2] Dept. of Stem Cell and Regenerative Biology, Harvard

University; [3] Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard University; [4] Program in

Neuroscience, Stony Brook University; [5] Program in Neuroscience and Medical Scientist Training Program, Stony Brook

University; [1α]-Fudan University; [1b] Shanghai Jiaotong University Medical School; [c] Dept. of Psychiatry, Stanford

University School of Medicine

Genetic dissection of glutamatergic neuron subpopulations and developmental trajectories in the cerebral cortex

Diverse types of glutamatergic pyramidal neurons (PyNs) mediate the myriad processing streams and output channels of

the cerebral cortex, yet all derive from neural progenitors of the embryonic dorsal telencephalon. Here, we establish

genetic strategies and tools for dissecting and fate mapping PyN subpopulations based on their developmental and

molecular programs. We leverage key transcription factors and effector genes to systematically target the temporal

patterning programs in progenitors and differentiation programs in postmitotic neurons. We generated over a dozen of

temporally inducible mouse Cre and Flp knock-in driver lines to enable combinatorial targeting of major progenitor types

and projection classes. Intersectional converter lines confer viral access to specific subsets defined by developmental

origin, marker expression, anatomical location and projection targets. These strategies establish an experimental

framework for multi-modal characterization of PyN subpopulations and tracking their developmental trajectories toward

elucidating the organization and assembly of cortical processing networks and output channels. This work was supported

in part by the NIH grants 5R01MH101268-05 and 5U19MH114821-03 to Z.J.H. and P.A., 1S10OD021759-01 to Z.J.H.,

the CSHL Robertson Neuroscience Fund to Z.J.H. P.O. is supported by NIH U01 MH114824-01.

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Hisham Mohammed, Yue Li, Paola Di Grazia, Sydney Agger, Amanda Bernstein, Rachel Garn and Edmund Hollis

Circuit Repair Laboratory, Burke Neurological Institute, Weill Cornell Medicine

A Modified Behavioral Test of Forelimb Dexterity in Mice

Hand and arm manual dexterity is a hallmark of humans and non-human primates. While rodents are less dexterous than

primates, they provide powerful models for testing neural circuit function in behavioral output, including dexterous

behaviors. In rodents, dexterous forelimb behavior is commonly tested on the single pellet reach task. The single pellet

reach task has been used extensively to study both motor learning as well as recovery from injury; however, mice exhibit

high variability in task acquisition in comparison to rats and a significant percentage fail to improve with training. We

created a recessed version requiring greater dexterity. This modification increased task difficulty as well as the proportion

of mice whose performance increased over time. Furthermore, inactivation of the motor cortex showed a greater effect on

the recessed version of the task. The kinematic analysis revealed differences in the reaching and grasping components of

skilled reach upon transient cortical inhibition. In summary, the recessed single pellet reach provides a robust assessment

of forelimb dexterity in mice and a tool for studying skilled motor acquisition and execution. (Burke Foundation and NIH

Common Fund DP2 NS106663 to EH. HM and YL received post-doctoral fellowships from NYS DoH SCIRB).

William Olson, Duo Xu, Varun Chokshi, Daniel O’Connor

Department of Neuroscience, Johns Hopkins University

Jaw movement-modulated activity of sensory neurons in the mesencephlic trigeminal nucleus during a

directional licking task

While the activity of muscle spindle (MS) sensory afferents is known to be modulated by position and movement of the

body, the movement coding of these neurons remains poorly defined in the context of voluntary behavior. Here, we

record from MS afferents innervating the jaw musculature (located in the mesencephalic trigeminal nucleus, MEV) of

mice performing a directional licking task. In this task, head fixed mice are trained to lick a moving ‘port’ through an arc

of seven locations surrounding the mouse’s face to receive a water reward. Advancement of the port is contingent on

each lick, so that movement through the sequence is driven by the mouse. This task elicits jaw trajectories along three

anatomical axes (dorsoventral, mediolateral, anterior-posterior) that we can track in high speed video recordings of the

face. Further, we can isolate single MS afferents from MEV extracellular tetrode recordings while simultaneously

recording masseter muscle activity via implanted EMG electrodes. Relation of neural activity to jaw kinematics reveals a

rich diversity of single-unit movement coding properties that we can leverage to better define the information provided by

these afferents during coordinated orofacial behaviors. Supported by NIH grants F32MH120873, R01NS089652, and

R01NS104834

Hyein Park, Darren Chu, Hayagreeve Keri, and Scott Pluta

Department of Biological Sciences, Purdue University

Cortical circuits unifying bilateral space

To form a unified percept of the environment, animals must share sensory information between their cerebral

hemispheres. This process of bilateral integration is essential for guiding many natural behaviors, such as handling

objects, localizing sound, and orienting gaze. Similarly, mice maneuver between obstacles, hunt insects, and navigate

through complex burrows in the dark, requiring them to compare the somatotopic relationship between objects on both

sides of their face. How do bilateral somatotopic maps share information between the hemispheres to guide these

complex, goal-directed behaviors? To answer this question, we developed a whisker-guided bilateral discrimination task

(go/no-go). To solve the task, mice must form a bilateral percept that encodes the somatotopic relationship between

objects on each side of their face. To understand the neural mechanisms underlying the formation of this bilateral

percept, we are combining our novel bilateral discrimination behavior with large-scale bilateral electrophysiology, high-

speed kinematic tracking of whisker movement, and optogenetic silencing of interhemispheric neurons.

A. Pala, M. E. McDonnell, B. Chen, G.B. Stanley

Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University

Integration of bilateral tactile signals in somatosensory cortices of the awake mouse

Tactile signals from the left and right sides of the body must be integrated to form a unified representation of the world.

While stimulation of one body side mainly elicits neuronal activity in the opposite hemisphere, ipsilateral activity has also

been observed in primary (S1) and secondary (S2) somatosensory cortices. Whether and how individual neurons of S1

and S2 integrate ipsilateral and contralateral signals is still unclear, and whether body movements modulate signal

integration is unknown. Here, using laminar silicon probes we measured the spiking activity of regular-spiking (RS, n=782)

and fast-spiking (FS, n=195) neurons in whisker S1 and S2 in response to unilateral and bilateral single-whisker stimuli in

awake head-fixed mice. As expected, unilateral whisker stimuli elicited strong contralateral responses in S1 and S2. In

BARRELS XXXIII POSTER ABSTRACTS

contrast, we observed a suppression of the firing rate of ipsilateral RS (but not FS) neurons in both S1 and S2. When

ipsilateral and contralateral stimuli occurred simultaneously, S1 and S2 RS responses, especially in layers 4 and 5a, were

smaller than responses to contralateral stimuli alone, even during whisking. Our findings suggest that the reduction of

response amplitude during bilateral stimulation may be a principle of interhemispheric signal integration common to S1

and S2 with potential relevance for bilateral tactile stimulus encoding and perception. NIH R01NS104928, R21NS112783,

Swiss NSF postdoc fellowship to AP.

Georgia M. Pierce (1), Gabriella M. Sahyoun (2), Randy M. Bruno (1)

[1] Zuckerman Institute, Columbia University, [2] Dept of Neuroscience and Behavior, Barnard College

Not-so-sensory activity in the posterior medial nucleus of the thalamus

Each primary sensory cortex gets input from corresponding primary and secondary thalamic nuclei. While primary

thalamic nuclei are characterized by their sensory responses, the degree to which secondary thalamus encodes sensory

and non-sensory signals is unknown. In the whisker system, the primary nucleus is the ventral posterior nucleus (VPM)

and the secondary nucleus is the posterior medial nucleus (POm). While VPM sends precise whisker touch signals to

cortex, POm responses are not well understood. Unlike VPM, POm is interconnected with many cortical areas, including

motor cortex and multisensory areas. POm, as a recipient of both bottom-up whisker signals and top-down cortical

signals, might integrate touch with non-somatosensory signals such as cross-modal sensory cues, reward, or

movement. We assessed POm’s response to touch with multi-whisker stimuli; to cross-modal signals with auditory cues;

to reward with water; and to movement by measuring whisking and licking. We recorded responses in a large number of

neurons with two-photon microscopy through gradient index lenses in awake mice. Self-generated movements

modulated a large number of POm neurons. Despite using touch stimuli expected to drive a somatosensory area, fewer

POm neurons were modulated by touch. Rewards and auditory cues were not reliable modulators. Our results suggest

that POm is driven by self-movement or the internal state signals that accompany it, such as arousal. NIH/NINDS R01

NS069679,F31 NS098670

Rikki Rabinovich, Daniel Kato, Randy Bruno

Zuckerman Institute, Columbia University

Learning-related changes in activity of superficial layer cells in barrel cortex

While primary sensory cortex is clearly involved in sensation, its precise role in behavior and sensory processing

remains somewhat elusive. For instance, cells in superficial cortical layers exhibit sparse activity, even in the presence

of strong sensory stimuli. Here, we investigated the possibility that behavioral learning alters activity patterns in

superficial layers. We used 2-photon calcium imaging to monitor neuronal activity as mice learned and performed a

Pavlovian whisker-based object detection task. Early in training, cells were on average relatively inactive, but as mice

began to learn the task, the cells began to respond more strongly to the stimulus. Cells exhibited categories of activity:

while some cells were unresponsive, some responded early in the trial upon stimulus arrival; others responded when the

stimulus was removed; still others responded late in the trial after reward presentation. As animals became proficient at

the task, many cells switched from a state of general inactivity to showing a strong response to the stimulus. These

findings imply that the response of superficial primary cortical cells to a stimulus is modulated by “higher-order” factors,

such as the relevance or value of the stimulus, or the behavioral state (attentive, motivated, etc) of the animal. Funding:

NIH/NINDS R01 NS069679; NSF GRFP

Deepa L. Ramamurthy, UC Berkeley; Daniel E. Feldman

UC Berkeley

Recent trial history cues attentional selection of whisker stimuli in miceRecent trial history cues attentional

selection of whisker stimuli in mice

The ability to selectively direct attention to behaviorally relevant stimuli is critical for animals in complex environments. To

examine effects of stimulus statistics and performance history on sensory processing, we trained head-fixed mice to

perform a Go/NoGo whisker detection task. Mice had 9 whiskers inserted in a piezo array and were required to lick in

response to random single whisker deflections and suppress licks in the absence of stimuli. Hits were rewarded, while

false alarms were neither rewarded nor punished. On trials immediately preceded by a single hit, mice performed

relatively less well compared to trials not preceded by a hit, primarily due to an increase in false alarms following reward

delivery. However, on trials preceded by 2-4 consecutive hits, whisker detection sensitivity (d’) was significantly enhanced

despite the elevated false alarm rate, due to an increase in hit rate with the number of previous successful detections.

Moreover, consecutive hits on repetitions of the same whisker stimulus resulted in an even larger improvement in d’,

relative to randomly interleaved stimuli. Thus, mice used recent trial history to modulate sensory processing to specific

whisker stimuli on a rapid timescale, consistent with attentional selection. In future experiments, we will investigate the

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role of cortical interneuron circuits in gating enhanced sensory detection during attentional selection in mice. Funding: NIH

1 F32 NS114327-01 (DLR), NIH R37NS092367 (DEF)

Cindy Ritter (1)*, Eduard Maier (1)*, Undine Schneeweiß (1), Tanja Wölk (1), Jean Simonnet (1), Safaa Malkawi (1) and

Michael Brecht (1,2)

[1] Bernstein Center for Computational Neuroscience Berlin, Humboldt-Universität zu Berlin, Bernstein Center for

Computational Neuroscience Berlin, Humboldt-Universität zu Berlin, [2] NeuroCure Cluster of Excellence, Humboldt-

Universität zu Berlin

An isomorphic three-dimensional cortical model of the pig rostrum

Physiological studies identified a somatosensory cortical gyrus represention of the pig snout. Here we describe the

anatomy of this gyrus and its extraordinary correspondence to the pig’s rostrum. Pigs engage their rostrum in skillful

rooting behavior. The nostrils have a rectangular medial wall and a funnel-like lateral opening, the nasal channels are

obliquely oriented and run from lateral (surface) to medial (inside the animal). The pig’s cortical rostrum gyrus mimics

these rostrum features in great detail. Aspecialized very thick layer 4 wraps around the dorsal surface of the gyrus. The

putative representation of majorskin folds coincides with blood sinus and folds of the rostrum gyrus. The putative nostril

representation is a deep sulcus with an oblique orientation running from (in terms of the periphery) lateral to medial. Much

like rodent nostril cortex layer 4 is very thin in the pig nostril representation. The side of the nostril sulcus representing the

medial wall of the nostril is rectangular, whereas the side of the nostril sulcus representing the lateral wall has a funnel-like

appearance. Flat maps of the rostrum gyrus reveal a very large surface area (277mm2). We suggest this representation

of afferent information in a large precise three-dimensional rostrum model mediates isomorphic cortical computation.

Chris C Rodgers, Ramon Nogueira, B Christina Pil, Esther A Greeman, Stefano Fusi, Randy M Bruno

Zuckerman Institute, Columbia University

Behavioral strategies and neural representations for shape discrimination

Humans and other animals can identify objects by active touch, requiring the coordination of exploratory motion and tactile

sensation. Both the motor strategies and neural representations employed could depend on the subject’s goals. We

developed a shape discrimination task that challenged head-fixed mice to discriminate concave from convex shapes.

Behavioral decoding revealed that mice did this by comparing contacts across whiskers. In contrast, mice performing a

shape detection task simply summed up contacts over whiskers. We recorded populations of neurons in the barrel cortex,

which processes whisker input, to identify how it encoded the corresponding sensorimotor variables. Neurons across the

cortical layers encoded touch, whisker motion, and task-related signals. Sensory representations were task-specific:

during shape discrimination, neurons responded most robustly to behaviorally relevant whiskers, overriding somatotopy.

Thus, sensory cortex can be dramatically reconfigured for the task at hand. Support was provided by NINDS/NIH

(R01NS094659, R01NS069679, F32NS096819, and U01NS099726); NeuroNex (DBI-1707398); Northrop Grumman; the

Gatsby Charitable Foundation (GAT3419); a Grossman-Kavli Scholar Award (to RB); a Kavli Institute for Brain Science

postdoctoral fellowship (to CR); and a Brain & Behavior Research Foundation Young Investigator Award (to CR).

Clément Brunner*, Micheline Grillet*, Arnau Sans-Dublanc, Karl Farrow, Théo Lambert, Emilie Macé, Gabriel Montaldo

& Alan Urban. *Authors contributed equally.

Neuro-Electronics Research Flanders, VIB, Imec, KU Leuven, Max Planck Institute of Neurobiology

A platform for brain-wide functional ultrasound imaging and analysis of circuit dynamics in behaving mice

Imaging of large-scale circuit dynamics is crucial to gain a better understanding of brain function, but most techniques

have a limited depth of field. Here we describe vfUSI, a platform for brain-wide volumetric functional ultrasound imaging

of hemodynamic activity in awake head-fixed mice. We combined high-frequency 1024-channel 2D-array transducer

with advanced multiplexing and high-performance computing for real-time 3D Power Doppler imaging at high

spatiotemporal resolution (220x280x175-µm3 voxel size, up to 6 Hz). In addition, we developed a standardized software

pipeline for registration and segmentation based on the Allen Mouse Common Coordinate Framework, allowing for

temporal analysis in 268 individual brain regions. We demonstrate the high sensitivity of vfUSI in multiple experimental

situations where stimulus-evoked activity can be recorded using a minimal number of trials. We also mapped neural

circuits in vivo across the whole brain during optogenetic activation of specific cell-types. Moreover, we revealed the

sequential activation of sensory-motor regions during a grasping water droplet task. vfUSI will become a key

neuroimaging technology because it combines ease of use, reliability, and affordability. Funding This work was

supported by grants from the Leducq Foundation (15CVD02), from FWO (MEDI-RESCU2-AKUL/17/049, G091719N,

and 1197818N), from VIB TechWatch (fUSI-MICE) and from internal NERF TechDev fund (3D-fUSI project).

BARRELS XXXIII POSTER ABSTRACTS

Yu Ding and Yuri Vlasov

University of Illinois at Urbana-Champaign

High-frequency whisker vibrations above 1KHz - are they relevant to perception?

We performed a systematic study of high -frequency vibrations of rodents whiskers using acoustical methods. We

identified a regular series of higher order modes ( up to 30) spanning frequencies up to 10KHz. While interaction of a

whisker with a pole excites mostly lower-order modes (80% of total energy), interaction with a textured surface

redistributes over 60% of these vibrational energy to modes higher than 1KHz. Moreover, these higher order modes

exhibit up to 15X smaller damping ratio and are propagating 4X faster, that makes them the fastest and the most powerful

messengers of shock-wave events during whisker scan over textured surfaces. Based on these observations we propose

a hypothesis of mechanical transduction that can explain observation of ultrafast microseconds-scale jitter in response of

primary afferents to fast whisker stimulations.

Isis Wyche (1), Kyle S. Severson (2), Daniel H. O'Connor (1)

[1] Department of Neuroscience, Johns Hopkins University School of Medicine; [2] Department of Neurobiology, Duke

University School of Medicine

Whisker inertia contributes to self-motion encoding in the mouse whisker system

A recent hypothesis on self-motion encoding in the mouse whisker somatosensory system, which lacks classical

proprioceptors, proposes that self-motion parameters of the whisk cycle are encoded on the basis of the whisker’s

bending and the contraction of the whisking muscles. To test the contribution of whisker bending to the encoding of

whisker self-motion in the absence of touch, we varied the inertia of the whiskers of actively whisking mice through

weighting and cutting, while recording the responses of multiple single units in the trigeminal ganglion and the primary and

secondary vibrissal somatosensory cortical areas. We quantified the mutual information between single unit spiking and

parameters of self-motion. An observed increase in the encoded whisker self-motion information in the weighted condition

and decrease in the cut condition – in units responsive to changes in whisker inertia – supports the hypothesis that

whisker bending contributes to the encoding of whisker self-motion.

Participants – BARRELS XXXIII 2020

Agmon, Ariel

Ahissar, Ehud

Ahrens, Allison

Aksham, Amit

Aman, Joseph

An, Christopher

An, Xu

Arber, Silvia

Armstrong, Alex

Aruljothi, Krithiga

Azevedo, Anthony

Baker, Jacob

Banerjee, Abhishek

Barrientos, Alicia C.

Bast, Arco

Bech Vilaseca, Pol

Benezra, Sam

Bernal-Garcia, Sergio

Berta, Kathleen

Bitzidou, Malamati

Bohannon, Briana

Bokiniec, Phill

Boscher, Flore

Bourdieu, Laurent

Bright, Simon

Brown, Solange

Brumberg, Joshua

Bruno, Randy

Burnett, Thomas

Bush, Nicholas

Butyrkin, Vladimir

Callado Perez, Amalia

Carta, Mario

Cataldo, Giuseppe

Chadderton, Paul

Chang, Yi-Ting

Chari, Trishala

Chen, Jerry

Chinta, Suma

Chirich, Lara

Chokshi, Varun

Chu, Yun Wen

Clough, Mitchell

Cohen, B Isaac

Concha, Miguel

Condylis, Cameron

Creson, Cris

Crochet, Sylvain

Cruikshank, Scott

Dagher, Sarah

Dasgupta, Rajan

Dave, Sonya

de Kock, Christiaan

de Laittre, Elizabeth

DeLaTorre, Nancy

Deschênes, Martin

Ding, Yu

Dobler, Zoe

Dobrzański, Grzegorz

Dolensek, Nejc

Dominiak, Sina

Dong, Mingyuan

Ebbesen, Christian

Efron, Ben

Ego-Stengel, Valerie

El-Boustani, Sami

Erskine, Andrew

Erzurumlu, Reha

Esmaeili, Vahid

Evans, Mathew

Fassihi, Arash

Fekir, Sinda

Feldman, Dan

Ferezou, Isabelle

Fidelin, Kevin

Forrest, Hamish

Foustoukos, Georgios

Franchini, Daniela

Fruengel, Rieke

Gabriella, Ivett

Galbavy, William

Gallero-Salas, Yasir

Gantar, Luka

Gaspar, Patricia

George, Benjamin

Ghanbari, Abed

Gogolla, Nadine

Goins, Jessica

Golomb, David

Goz, Roman

Grillet, Micheline

Groh, Alexander

Gupta, Kalpana

Guyoton, Maëlle

Habjan, Caroline

Hakim, Richard

Harano, Nina

Hartmann, Mitra

Helmchen, Fritjof

Hickmott, Peter

Hoffmann, Adrian

Hong, Kate

Hooks, Bryan

Hostetler, Rachel

House, Garrett

Hu, Kun

Huang, Jun

Huang, Z. Josh

Hubatz, Sophie

Huber, Daniel

Inacio, Ana

Ishiyama, Shimpei

Issa, Habon

Jablonk, Jan

Jaeger, Dieter

Jeong, Daeun

Jeong, Yeongseok

Jin, Miaomiao

Johnson, Kenji

Jost-Mousseau, Timothé

Kahl, Taylor

Kanodia, Harsh

Kato, Daniel

Katz, Yonatan

Kawatani, Masahiro

Keller, Asaf

Keri, Hayagreev

Khan, Vardah

Kil, Dries

Kim, Ethan

Kim, Jinho

Kim, Su-Jeong

Kim, Taehyeon

King, Samson

Kleczka, Kevin

Klein, Alexandra

Kleinfeld, David

Kourdougli, Nazim

Kozlova, Elena

Krishnan, Keerthi

Kublik, Ewa

Kwon, Samuel

Lam, Angelina

Lambot, Laurie

Lammers, Alex

Lampl, Ilan

Lau, Billy

Layo, Dana

Ledderose, Julia

Lee, Christian

Lee, David

Lee, Kuo-Sheng

Lee, Soohyun

Lee, Suhjin

Lees, Robert

Leger, Jean-Francois

Lemercier, Clement

Lenschow, Constanze

Levy, Manuel

Li, Chen

Li, Shun

Li, Wanru

Liew, Michael

Liew, Yi Juin

Liu, Rui

Participants – BARRELS XXXIII 2020

Loeb, Gerald

Loidolt, Matthias

London, Tanisha

Long, Michael

Lu, Ju

Lukasiewicz, Kacper

Luna, Glenys

Lustig, Brian

Lutchman, Sarah

Maciel, Marta

Maharjan, Aman

Maier, Eduard

Maire, Phillip

Manjrekar, Nikita

Maravall, Miguel

Margolis, David

Maristany, Eduardo

Marreo, Krista

Masood, Anas

Matho, Katie

Matteucci, Giulio

Mease, Rebecca

Meeuwissen, Anouk

Megemont, Marine

Mercer Lindsay, Nicole

Meyer, Elisabeth

Michaelson, Sheldon

Mo, Christina

Moberg, Sara

Mohammed, Hisham

Moore, Christopher

Morabito, Annunziato

Morandell, Karin

More, Alexander

Moreno-Lopez, Yunuen

Morishita, Hirofumi

Mosberger, Alice

Moss, Morgane

Motaharinia, Mohammad

Munoz, William

Nambiar, Jithin

Naskar, Shovan

O'Connor, Daniel

Oberlaender, Marcel

Olson, William

Oran, Yael

Oryshchuk, Anastasiia

Packer, Adam

Pala, Aurélie

Palacios, Ensor

Palmer, Lucy

Panzeri, Matteo

Park, Hyein

Park, Jung

Petty, Gordon

Peuvrier, Mathias

Pierce, Georgia

Pluta, Scott

Preuss, Felix

Prevosto, Vincent

Prsa, Mario

Qi, Guanxiao

Rabinovich, Rikki

Rachel, Jenifer

Ramamurthy, Deepa

Reeson, Patrick

Reinartz, Sebastian

Rhoades, Jeff

Rinkus, Gerard

Ritter, Cindy

Rodgers, Chris

Rodriguez, Lucia

Rogerson-Wood, Lara

Roy Chowdhury, Ritu

Ruckstuhl, Maxwell

Ruiz, Rebekah

Rumbaugh, Gavin

Sachdev, Robert

Saha, Tanmayika

Sahyoun, Gabriella

Sathyamurthy, Anupama

Sayed, Eden

Schlauri, Nadia

Schmidt, Ewoud

Schwarz, Cornelius

Sehara, Keisuke

Severson, Kyle

Shepherd, Gordon

Shin, Hyeyoung

Shyong, Jennifer

Silva Prieto, May Li

Silva Tortorelli, Lucas

Song, Kun

Sourmpis, Christos

Spiegel, Alina

Sridharan, Madhav

Staiger, Jochen

Sumser, Anton

Susi, Scott

Sych, Yaroslav

Taha, Ahmad

Takatoh, Jun

Takeoka, Aya

Tamura, Keita

Teska, Aleksandra

Tomaio, Jacquelyn

Tunckol, Elcin

Uddin, Israt

Urbain, Nadia

Urban, Alan

Vaissiere, Thomas

Vajtay, Thomas

Valtcheva, Silvana

Vandemark, Kaeli

Vargova, Greta

Vercelli, Alessandro

Vestergaard, Mikkel

Vieites Prado, Alba

Vlasov, Yurii

Waiblinger, Christian

Wang, Fan

Wang, Han Chin

Wang, Yunmiao

Watson, Brendon

Wei, Alan

Whitmire, Clarissa

Wright, Nathaniel

Wyche, Isis

Xiao, Shulan

Xu, Duo

Xu, Jiaying

Yamashita, Takayuki

Yamawaki, Naoki

Yang, Hongdian

Yanik, Mehmet

Yanqi, Liu

Yao, Pantong

Ye, Xin

Yeh, ShuHao

Yonk, Alex

Yu, Yan

Zagha, Edward

Zareian, Behzad

Zeiger, William

Zhang, Chuanqiang

Zhang, Linghua

Zhang, Zhaoran

Zhao, Wen-Jie

Zhao, Zhilei

Zou, Jing

Zuo, Yi