Role of the dopaminergic system in the cataleptogenic action of bulbocapnine.

Time courses of the behavioural and biochemical effects of a cataleptogenic dose (50 mg kg-1 i.p.) of bulbocapnine have been studied in the rat. Catalepsy ensues immediately after administration of the drug and lasts 1 h. Concomitant with the onset of catalepsy there is a rise in HVA and DOPAC concentrations in whole and discrete parts of the brain (striatum, limbic system). Dopamine content does not change in whole brain but it decreases in the striatum and increases in the cortex and hippocampus. No significant effects on NA, 5-HT and 5 HIAA concentrations were observed.