Tim Buschmann: Mechanisms Controlling Cortex-Wide Neural Dynamics

Princeton Neuroscience Institute

Cognition arises from the dynamic interaction between brain regions. As neural activity flows from one region to the next, it carries and transforms the information necessary for behavior. In this talk, I will present recent work from my lab aimed at quantifying and understanding cortex-wide dynamics in mice. Combining cortex-wide calcium imaging and multi-region electrophysiology, we tracked the evolution of neural activity across cortical (and sub-cortical) regions while mice engaged in spontaneous behaviors. Cortex-wide neural activity was surprisingly low-dimensional – it could be decomposed into a set of ~15 ‘motifs’. Each motif captured a unique spatio-temporal pattern of neural activity that spanned the entire cortex and lasted for ~1 second. The same motifs were observed across individuals and in different behavioral contexts. However, the rate at which each motif was expressed differed between individuals and contexts, and was highly correlated with changes in behavior. Finally, leveraging our simultaneous electrophysiological recordings, we investigated how the activity of a population of neurons within a brain region was related to mesoscale changes in the flow of neural activity between regions. This revealed different dimensions of neural activity within each region was functionally coupled with a network of other regions. Aligning neural activity to these dimensions determined how that activity propagated to other regions. Altogether, our results suggest a geometrical model of cognitive control, that relies on the dynamic alignment of neural activity to determine what and how neural representations flow through the brain.

 

Guests are welcome!

 

Organized by

Klaus Obermayer / Margret Franke