[Myoclonic hyperkinesis induced by repeated administration of picrotoxin into rat neostriatum].

The effects of three-week daily intrastriatal 45 mcg GABA, 5 and 15 mcg picrotoxin and 5 bicuculline microinjections in rats were investigated. The inhibition of avoidance conditioning in shuttle box was registered in first days of GABA microinjection; stereotyped behaviour and paradoxal freezing in further GABA effects were developed. After the short orofacial dyskinesia as the acute picrotoxin effects, the choreo-myoclonic limb jerks, with the distinct generalization stage were observed. Picrotoxin dose increasing in toxic convulsive status results. No any dystonia, but strong avoidance conditioning inhibition in all three weeks of bicuculline treatment were observed only. The novel functional and controlled model of choreo-myoclonic hyperkinesis is proposed. The role of the striatal GABA system in human neuro-motor dyskinesias were discussed.