The Center for Neural Circuit Mapping will host guest speaker Dr. Mark Wagner, Stadtman Investigator at NIH/NINDS.

Cerebellar computations across motor and cognitive behaviors

The cerebellum contains most of the brain’s neurons and interconnects with the entire neocortex, forming a basic neuroanatomical motif. With evolution, the cerebellum expanded by orders of magnitude but mainly by replicating the same crystalline microcircuit. In humans, movement, learning, attention, working memory, and language all engage cerebellar networks. Is there a single “cerebellar computation” useful for all behaviors, or do new dynamics emerge from higher brain function? We aim to understand the basic computations implemented in cerebellar circuits, their broad utility across the neocortex, and how they flexibly contribute to many disparate behaviors. Via recordings from cerebellar granule cells in animals executing rewarded actions, we showed that numerous granule cells anticipated reward delivery (Wagner et al Nature 2017). By developing simultaneous neocortex-cerebellum imaging, we found that characteristically neocortical neural activity develops in tandem with similar cerebellar activity patterns during skill learning (Wagner et al Cell 2019). We also broadened understanding of cerebellar climbing fibers, demonstrating that they can become increasingly synchronized during skilled actions as animals gain expertise (Wagner et al Cell 2021). Recently, via simultaneous imaging of cerebellar granule cells and climbing fibers, we found that seconds-long granule cell neural ramps enable the cerebellum to learn to track elapsed time until an expected rewarding outcome (Garcia-Garcia et al Neuron 2024). We are working to determine how: neocortical information is transformed into the cerebellum; cerebellar computation generalizes across behavioral contexts and reward modalities; and the cerebellum routes its output across many downstream circuits throughout the brain