The effect of amphetamine and L-dopa on tetrabenazine-induced suppression of intracranial self-stimulation in the rat.
The administration of d-amphetamine sulphate resulted in a restoration of intracranial self-stimulation (ICSS) suppressed by tetrabenazine (TBZ). A dose-dependent increase in the rate of ICSS was seen after L-dopa in animals pretreated with TBZ. d-Amhetamine is believed to act by facilitating the nerve-impulse induced release of central catecholamines (CA) whereas the blockage of the granular uptake-storage mechanism by TBZ will prevent the storage of CA formed from the administrated L-dopa and thereby interfere with their release by nerve-impulses. Thus, in the latter case, an activation of central CA receptors in all probability will be due to a dose-dependent diffusion of CA from nerve terminals. It is suggested that the failure to completely antagonize the TBZ-induced suppression of behaviour by L-dopa is due to the fact that a direct activation, independent of the nerve-impulse flow, of central CA receptors easily results in an overstimulation and a reduced specificity in behaviour.
D000661:Amphetamine / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D003864:Depression, Chemical; D004305:Dose-Response Relationship, Drug; D006801:Humans; D007274:Injections, Intraperitoneal; D007980:Levodopa / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D051381:Rats; D012653:Self Stimulation / Q000187:drug effects*; D013747:Tetrabenazine / Q000494:pharmacology*
D007980:Levodopa; D000661:Amphetamine; D013747:Tetrabenazine