Dopaminergic effects of phencyclidine in rats with nigrostriatal lesions.

Phencyclidine produces a dose-dependent ipsilateral rotation in rats with unilateral substantia nigra lesions. This ipsilateral turning is decreased 41% by pretreatment with AMPT and 81% by prior administration of haloperidol. Ipsilateral turning elicited by phencyclidine can also be altered by treatment with cholinergic agents. These findings suggest that phencyclidine may be acting by increasing the availability of dopamine on the intact side of a unilaterally-lesioned substantia nigra rat and that the response can be modulated by alterations in the cholinergic system.