Beyond Motor Control: Diffusion MRI Reveals Associations between the Cerebello-VTA Pathway and Socio-affective Behaviors in Humans

The cerebellum, a structure best known for its role in motor control, sends extensive projections throughout the cerebral cortex and subcortex. At the gross anatomical level, the cerebellum can be divided into the anterior, posterior, and flocculonodular lobes, which are separated by fissures. It can also be subdivided medial-laterally into distinct zones based on afferent and efferent patterns: the vermis (spinocerebellum) and the paravermis (intermediate zone) receive direct inputs from the spinal cord and are responsible for movement error correction; the lateral hemispheres (cerebrocerebellum) receive extensive projections throughout the cerebral cortex and facilitate motor movement planning with the motor cortex; and the flocculonodular lobe (vestibulocerebellum) receives afferents from the vestibular system and is responsible for eye movement and equilibrium (De Benedictis et al., 2022). At the cellular level, the cerebellum can be divided into the superficial gray matter and deep white matter, which surrounds the deep cerebellar nuclei (DCN): the dentate, interposed, and fastigial nuclei. These nuclei are central points for efferent fibers to converge before exiting the cerebellum via the cerebellar peduncles. Finally, the gray matter of the cerebellar cortex is divided into an outermost molecular layer, a middle Purkinje layer, and an innermost granular layer, and it can be further subdivided into parasagittal stripes based on whether or not the Purkinje cells express the glycolytic enzyme zebrin (De Benedictis et al., 2022; Fig. 1). Figure 1. Cerebellar anatomy illustrated in folded and unfolded space. Left panel, Folded cerebellar anatomy based on the open-source cerebellum atlas (Diedrichsen et al., 2009, distributed under a Creative Common license CC BY-ND). Right panel, Schematic of the cerebellum in unfolded space. Red dotted lines demarcate sagittal segments used as seeding regions in Hoffman et al. (2024) for probabilistic tractography, focusing on Lobule VI, Crus I, and Crus II of the posterior cerebellum. … Correspondence should be addressed to Violet Liu at mliu2025{at}meds.uwo.ca.