Topography of dyskinesias and torticollis evoked by inhibition of substantia nigra pars reticulata

摘要: GABAergic neurons of the substantia nigra pars reticulata (SNpr) and globus pallidus interna (GPi) constitute output pathways basal ganglia. In monkeys, choreiform limb dyskinesias have been described after inhibition GPi, but not SNpr. Given anatomical functional similarities between these structures, we hypothesized that could be evoked by an appropriate region within The GABAA receptor agonist, muscimol, was infused into various sites SNpr adjacent STN freely moving macaques. effect antagonist, bicuculline (BIC), also examined. Muscimol (MUS) in following: (1) contralateral arm and/or leg from central lateral sites; (2) contralaterally directed torticollis posterior (3) contraversive quadrupedal rotation anterior sites. MUS infusions SN compacta or were without effect, ruling out a contribution drug spread to structures. BIC induced ipsiversive postures dyskinesia torticollis, whereas STN, it ballistic movements. This is first report highly site-specific obtained restricted distinct responsible for inducing torticollis. These results suggest overactivity different outputs mediates abnormalities are symptoms dystonia, Huntington's disease, iatrogenic dyskinesias, suggesting conditions may result, part, loss function efferent projections. © 2012 Movement Disorder Society