Randy Bruno: The many layers of tactile perception

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.

Duration of the talk:

Approx. 50 minutes, then general and specialized discussion.

The talk will be held online via Zoom

Meeting ID and password will be sent with e-mail invitation. You can also send an e-mail to katja.kukatz@bcf.uni-freiburg.de for meeting ID and password.

More about the speaker and his research

Neurobiology and Behavior

Host

Johann Bollmann