Abstract
Cerebellar outputs take almost exclusively polysynaptic routes to reach the rest of the brain, impeding conventional tracing efforts. Here we quantify pathways between cerebellar cortex and contralateral thalamic and corticostriatal structures using an anterograde (H129) transsynaptic tracer herpes simplex virus type 1, a retrograde (Bartha) tracer pseudorabies virus, and a whole-brain pipeline for neuron-level analysis using light-sheet microscopy. In ascending pathways, sensorimotor regions contained the most labeled neurons, but higher densities were found in associative areas, including orbital, anterior cingulate, prelimbic, and infralimbic cortex. Ascending paths passed through most thalamic nuclei, especially ventral posteromedial and lateral posterior (sensorimotor), mediodorsal (associative), and reticular (modulatory) nuclei. Retrograde tracing revealed that the majority of descending paths originate from somatomotor cortex. Patterns of ascending influence correlated with anatomical pathway strengths, as measured by brainwide mapping of c-Fos responses to optogenetic inhibition of Purkinje cells. Our results reveal parallel functional networks linking cerebellum to forebrain and suggest that cerebellum is capable of using sensory-motor information to guide both movement and nonmotor functions.
Competing Interest Statement
The authors have declared no competing interest.
Footnotes
Manuscript text revised after reviews; Figures 3-8 updated; Supplementary figures added