Dystonia or Dyskinesia Induced by Optogenetic Stimulation of Parafascicular Nucleus of Rat
Dyskinesia is a neurological disorder characterized by involuntary movement of the body due to the abnormal function of the basal ganglia, and the basal ganglia circuit is the target of treatment of this disease. The parafascicular nucleus (PF) plays pivotal roles in controlling of the basal ganglia, but it is not well known how PF affects the development of dyskinesia. Animal models of dyskinesia currently available have not linked to clinical study of treatment of dyskinesia. The reason of this discordance is absence of proper animal model suitable for integrative aspect of dyskinesia. This study was designed to develop an animal model of dyskinesia that is reversibly controllable by stimulating the PF using optogenetics. Fourteen animals were underwent stereotactic operation injecting a virus vector “AAV2−hSyn−ChR2−mCherry” to the lateral one third of the PF. Baseline and post-stimulation behavior test was done. As results, dyskinesias were found in 7 animals. Dyskinesia scores were significant increased after light stimulation compared to baseline. In rats with dyskinesia, it was confirmed that the mCherry was expressed in the PF, while the rats without dyskinesia did not present mCherry. In conclusion, it was found that dyskinesia could be reversibly induced when the PF was stimulated using an optogenetic method.