Striatal parvalbumin interneurons, not cholinergic interneurons, are activated in a mouse model of cerebellar dystonia.

Dystonia is supposed to arise from abnormalities in the motor loop of the basal ganglia; however, there is an ongoing debate regarding cerebellar involvement. We adopted the established cerebellar dystonia mice model by injecting ouabain to examine the contribution of the cerebellum. Initially, we examined whether the entopeduncular nucleus (EPN), substantia nigra pars reticulata (SNr), globus pallidus externus (GPe), and striatal neurons were activated in the model. Next, we examined whether dopamine D1 receptor agonists (D1 agonist) and dopamine D2 receptor antagonists (D2 antagonist) or selective ablation of striatal parvalbumin (PV) interneurons could modulate their involuntary movements. The cerebellar dystonia mice had a higher number of c-fos-positive cells in the EPN, SNr, and GPe, as well as a higher positive ratio of c-fos in striatal PV interneurons than the control mice. Furthermore, systemic administration of combined D1 agonist and D2 antagonist and selective ablation of striatal PV interneurons relieved their involuntary movements. Abnormalities in the motor loop of the basal ganglia could be crucially involved in cerebellar dystonia, and modulating PV interneurons might provide a novel treatment strategy.