[The effect of the activation and blockade of the neostriatal dopaminergic system on the hyperkinesis evoked in rats by the intrastriatal administration of picrotoxin].

The effects of three-week daily intrastriatal 5 micrograms picrotoxine microinjections (m.i.) and influences of preceding similar haloperidol, metoclopramide (5 micrograms) or amphetamine (15 micrograms) m.i. in rats were investigated. The oro-facial dyskinesia and intensive choreo-myoclonic limb jerks (with the distinct generalization) after the picrotoxine m.i. were prevented by metoclopramide and party inhibited by haloperidol intrastriatal m.i. No hyperkinetic stimulant effects of amphetamine were registered, on the contrary--some inhibiting effect of its m.i. 20-24 hours before picrotoxin were observed. The role of the striatal GABA and dopamine systems in neuromotor dyskinesias and their functional relationship are discussed.