The effect of amantadine on motor activity and catalepsy in rats

The effect of amantadine on motor activity was investigated in rats. The compound was used at doses which antagonized the catalepsy induced by spiroperidol, triperidol, chlorpromazine and reserpine. These doses moderately stimulated motor activity in normal rats; their activity was effectively antagonized by spiroperidol, chlorpromazine, phenoxybenzamine but only slightly, if at all, by -methyltyrosine, dimethyldithiocarbamate and reserpine. The behavioral effects of amantadine in normal and reserpinized rats were potentiated by l-DOPA, nialamide, desipramine and, in particular, by cocaine. The cocaine-induced potentiation of the amantadine effect was prevented by spiroperidol. -Methyltyrosine did not influence the antagonism of amantadine towards spiroperidol-induced catalepsy. Noradrenaline and dopamine levels in the whole brain and dopamine levels in the corpus striatum were unaltered by amantadine. The main mechanism of action of amantadine appears to be the activation of central dopamine receptors.