Cerebellum-Midbrain Reward Circuitry in Humans: an in vivo dissection with implications for socio-affective functioning

Poster Session B - Sunday, April 14, 2024, 8:00 – 10:00 am EDT, Sheraton Hall ABC

Linda Hoffman¹ (tuf72977@temple.edu), Julia Foley¹, Josiah Leong², Holly Sullivan-Toole¹, Blake Elliott¹, Ingrid Olson¹; ¹Temple University, ²University of Arkansas

Emerging research in non-human animals implicates cerebellar projections to the ventral tegmental area (VTA) in social and reward driven behaviors, but the circuits have not been characterized in humans. In this study, we mapped the cerebello-VTA structural connectivity in humans. We visualized and measured the structural connections by performing probabilistic tractography on diffusion weighted imaging data from the Human Connectome Project (HCP). We uncovered the topographical organization of the connections by separately tracking from parcels of cerebellar lobule VI, crus I/II, vermis, paravermis, and cerebrocerebellum. The results revealed that afferents from the cerebellum to the VTA predominantly originate in medial aspects of the right cerebellum and terminate mostly in ipsilateral VTA. The paravermis of Crus I, traveling through the interposed nucleus, sent the most connections to the VTA compared to the other lobules. Next, we examined the role in these tracts in social and affective functions by taking the tracts with the highest density, computing microstructure, and correlating with measures of affect, social functioning, and personality traits. We identified robust associations across multiple socio-affective domains. Taken together, we produced detailed maps of cerebello-VTA structural connectivity for the first time in humans and showed that this network plays a key role in driving socio-affective dysregulation in a normative sample.

Topic Area: EMOTION & SOCIAL: Other