Effect of methamphetamine on rotational behavior induced by anodal polarization of the substantia nigra in rats.

The effect of methamphetamine (MAMP) on rotational behaviour was studied in rats after unilateral application of an anodal direct current (3 microA, 30 min) to the substantia nigra pars compacta (SNC). The current application induced a transient increase of contralateral rotation which declined within 30 min. An intraperitoneal injection of MAMP enhanced the effects of the direct current for more than 60 min. The results suggest that anodal direct currents induce activation of nigrostriatal dopaminergic system leading to increases in rotational behavior.