PURKINJE CELL ACTIVITY CHANGES IN CEREBELLAR SUBREGIONS DURING FEAR CONDITIONING

The cerebellum has classically been known in its role in motor learning and coordination. However, recently the cerebellum has also been recognized in playing a key role in emotional regulation, specifically in modulating fear behavior. The collective activity of Purkinje cells (PCs) across cerebellar regions during fear learning remains unexplored. To address this gap, we implemented the targeted recombination in active populations (TRAP) system to investigate intracerebellar PC activity during cue dependent fear conditioning in mice. Our results indicate that PC activity was reduced in areas previously suggested to play a role in controlling aversive emotions, which included cerebellar subregions of Crus I, Crus II and lobule VI. Moreover, these reductions were more pronounced in the left cerebellar hemisphere. Increased PC activity was observed in the lobule VIII subareas of the right cerebellar hemisphere. Additional PC activity changes related to motor function were also observed from the subregions of the paraflocculus and the copula pyramidis. Our findings not only highlight the importance of the cerebellum and its subregions in the context of fear learning but also sheds light on the potential lateralization of fear emotions in the cerebellum.