CEREBELLAR CONTRIBUTION TO DECISION MAKING: UNRAVELLING THE CEREBELLO-ORBITOFRONTAL CORTEX PATHWAY

Decision-making is a high-order cognitive function essential for adaptive behavior, and its impairment is a hallmark of psychiatric disorders such as depression, schizophrenia, and autism. These deficits often appear as impulsivity, poor judgment, and maladaptive choices, leading to negative clinical outcomes. While the orbitofrontal cortex (OFC) is a central hub for integrating sensory and emotional information to guide advantageous decisions, evidence shows that the cerebellum, traditionally linked to motor control, also contributes to cognition. Studies in humans and rodents reveal that specific cerebellar regions form di-synaptic pathways with prefrontal areas via thalamic relays, notably the mediodorsal (MD) and ventromedial (VM) nuclei. Cerebellar dysfunction can induce cognitive and affective disturbances, including impulsivity, similar to OFC impairments, highlighting the importance of cerebello–prefrontal interactions in decision-making. This project tests the hypothesis that the cerebellum modulates decision-making through projections to the OFC. Using rats, we combine viral circuit tracing, electrophysiology, and optogenetics to (1) map cerebello–OFC pathways, (2) evaluate circuit inhibition effects during impulsive choice and action tasks, and (3) characterize neural dynamics linking the fastigial nucleus (FN) and OFC during behavior. Preliminary tracing confirms a FN→MD→OFC disynaptic pathway, and early electrophysiological recordings show coordinated FN–OFC activity during open-field exploration. Ongoing work will assess how these structures interact during delay-discounting and Go/No-Go tasks, and how cerebellar output causally influences OFC activity and decision-making. Overall, these findings aim to clarify the role of cerebello–OFC circuits in adaptive behavior and their contribution to the cognitive processes underlying decision-making.