Rotational behavior induced in rats by intranigral application of GABA-related drugs and GABA antagonists

GABA and GABA-related drugs such as muscimol, gamma-hydroxybutyric acid and baclofen injected unilaterally into the substantia nigra of rats elicited contraversive turning. Unilateral injections of picrotoxin and bicuculline produced either ipsi- or contraversive turning depending on the volume of vehicle. I.p. applied haloperidol did not abolish the muscimol-induced turning. This and the direction of rotational behavior suggests that the turning behavior elicited by GABA-related drugs is not mediated by the nigrostriatal dopaminergic tract.