Christian Hansel: Instructive cerebellar signals guide neocortical plasticity

University of Chicago

The classic example of supervised learning in the brain occurs at the parallel fiber (PF) to Purkinje cell synapse in the cerebellum, where plasticity depends on co-activity of the climbing fiber (CF) input. According to the Marr-Albus-Ito theory of cerebellar function, this CF input provides an instructive signal for cerebellar learning.
In my laboratory at the University of Chicago, we have studied CF signaling and its role in cerebellar (PF) plasticity for many years. Recently, however, we have asked a new question: does CF activity also provide an instructive signal outside the cerebellum? The answer to this question is yes, and I would like to present data from two-photon recordings of GCaMP6f encoded calcium signals in the mouse primary somatosensory cortex (S1), combined with optogenetic CF activation in the cerebellum, to make that argument. I will demonstrate that whisker activation triggers receptive field plasticity in the S1 barrel cortex, and that this form of experience-dependent plasticity is prevented by CF co-activation. (Unpublished data.)
In addition, I will present (extended) findings from a recent publication from our lab (Busch and Hansel, Science 381, 2023) that show that human Purkinje cells differ in morphology quite substantially from their murine counterparts, with consequences for CF signaling. I will also share unpublished stainings of macaque Purkinje cells (and other species) to demonstrate evolutionary aspects of interest.

 

Guests are welcome!

 

Organized by

Michael Brecht / Margret Franke