The Many Layers of Touch

Speaker: Randy Bruno

Abstract:

Perception, decision making, and movement are enhanced by cortical circuitry, which has a stereotyped architecture repeated across the entire surface of the brain. We have previously shown that ascending signals from thalamus are duplicated in the superficial and deep cortical layers, allowing the two sets of layers to function independently despite their dense interconnections. In this talk, I will discuss our investigations of how the different cortical layers contribute to behavior. I will show how modern optogenetic and traditional lesion manipulations can lead to opposing conclusions about the necessity of a brain structure, layer, or cell type to a behavior. We have found that subcortical systems suffice for several tasks widely used to study rodent cortex. Using novel cortex-dependent tasks, we have observed that deep cortical layers supply the critical output for behavioral performance and superficial cortical layers may alter deep layer function by task context. Encoder models reveal that neurons recorded in primary somatosensory cortex have mixed selectivity for sensory, motor, choice, and reward signals. Task context can reweight this mixture so dramatically that even somatotopic organization disappears. Learning-induced changes to apical tuft dendrites in layer 1 may be a substrate by which top-down context reconfigures sensory cortex on a task-by-task basis.

About the speaker:

Randy Bruno is an Associate Professor of Neuroscience at Columbia University and a principal investigator at the Zuckerman Mind Brain Behavior Institute. He is also a member of the Kavli Institute for Brain Science. Professor Bruno earned his PhD in Neurobiology with Daniel J. Simons at the University of Pittsburgh School of Medicine and performed postdoctoral research with Bert Sakmann at the Max Planck Institute for Medical Research in Heidelberg. The main goal of his research program is to understand how the architecture of local circuitry in the cerebral cortex contributes to perception, learning, and decision making. His work has earned several honors, including the Society for Neuroscience’s Young Investigator Award. His lab is presently focused on the computational and behavioral roles of cortical layers and thalamic nuclei in sensory-guided behaviors.

Time and place:

May 26, 2021, 4:00 p.m. CEST

The talk will be held online to a restricted audience of registered attendees only.

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