The deep cerebellar nuclei to striatum disynaptic connection contributes to skilled forelimb movement.

Cerebellar-thalamo-striatal synaptic communication has been implicated in a wide range of behaviors, including goal-directed actions, and is altered in cerebellar dystonia. However, its detailed connectivity through the thalamus and its contribution to the execution of forelimb movements is unclear. Here, we use trans-synaptic and retrograde tracing, ex vivo slice recordings, and optogenetic inhibitions during the execution of unidirectional or sequential joystick displacements to demonstrate that the deep cerebellar nuclei (DCN) influence the dorsal striatum with a very high probability.

Optogenetic inhibition of indirect pathway neurons in the dorsomedial striatum reduces excessive grooming in Sapap3-knockout mice.

Excessive grooming of Sapap3-KO mice has been used as a model of obsessive-compulsive disorder (OCD). Previous studies suggest that dysregulation of cortico-striatal circuits is critically important in the generation of compulsive behaviors, and it has been proposed that the alteration in the activity patterns of striatal circuitry underlies the excessive grooming observed in Sapap3-KO mice. To test this hypothesis, we used in-vivo calcium imaging of individual cells to record striatal activity in these animals and optogenetic inhibition to manipulate this activity.

Perturbations in the Activity of Cholinergic Interneurons in the Dorsomedial Striatum Impairs the Update of Actions to an Instrumental Contingency Change.

The striatal cholinergic system is key in detecting changes in instrumental contingencies. While recent evidence supports this vision, cell type-specific online control on the activity of the cholinergic striatal neurons is necessary to empirically test it. In this study, we performed optogenetic manipulations of the activity of striatal cholinergic interneurons (CINs) to evaluate their contribution to the updating of a previously learned instrumental contingency.