Cognitive and social capacities require postnatal experience, yet the pathways by which experience guides development are unknown. In the paper published recently in eLife, Aleksandra Badura and colleagues show that the normal development of motor and nonmotor capacities requires cerebellar activity.
Using chemogenetic perturbation of molecular layer interneurons to attenuate cerebellar output in mice, the authors found that activity of posterior regions in juvenile life modulates adult expression of eyeblink conditioning (paravermal lobule VI, crus I), reversal learning (lobule VI), persistive behavior and novelty-seeking (lobule VII), and social preference (crus I/II). Perturbation in adult life altered only a subset of phenotypes. Both adult and juvenile disruption left gait metrics largely unaffected. Contributions to phenotypes increased with the amount of lobule inactivated. Furthermore an anterograde transsynaptic tracer showed that posterior cerebellum made strong connections with prelimbic, orbitofrontal, and anterior cingulate cortex.
These findings provide anatomical substrates for the clinical observation that cerebellar injury increases the risk of autism.