Effects of chronic lithium treatment on brain monoamine metabolism and amphetamine-induced locomotor stimulation in rats.

The aim of the present study was to investigate how chronic lithium treatment affects brain monoamine metabolism and amphetamine-induced locomotor stimulation in rats. Chronic lithium treatment was found to increase the synthesis of brain 5-hydroxytryptamine, an effect which may be mediated via increased brain levels of tryptophan. The synthesis and release of dopamine were, on the other hand, found to be decreased. Finally, chronic lithium treatment was found to suppress amphetamine-induced locomotor stimulation, probably due to counteraction by lithium on amphetamine-induced release of catecholamines.