Effects of Dopaminergic Stimulating Agents, Caffeine and Antipsychotic Drugs on Rotational Behaviour in Mice with Unilateral Striatal 6-Hydroxydopamine Lesions

Abstract

An improved technique of destroying dopaminergic nerve terminals following microinjection of 6-hydroxydopamine into the unilateral striatum of mice is described. Apomorphine hydrochloride 1.25 mg/kg produced intense rotation contralateral to the side of the lesion 10-20 days after 6-hydroxydopamine treatment. In these mice, L-dopa 20 and 40 mg/kg alone elicited marked contralateral rotation. Ergometrine maleate 10 and 20 mg/kg produced contralateral rotation which lasted over 2 h. Methamphetamine hydrochloride 2.5 and 5 mg/kg elicited long-lasting rotation ipsilateral to the side of the lesion. Rotation induced by apomorphine and methamphetamine was inhibited by the pretreatment with antipsychotic drugs (haloperidol, pimozide, chlorpromazine and sulpiride). Caffeine (25 and 50 mg/kg) produced long-lasting contralateral rotation, which was suppressed by pretreatment with pimozide. The rotational behavior of mice examined in the present study may be useful in the evaluation of dopaminergic stimulating activity of drugs.