Effects on hypothalamic self-stimulation of drugs influencing dopaminergic neurotransmission injected into nucleus accumbens and corpus striatum of rats.
The role of the nucleus accumbens septi (ACB) and corpus striatum (CPU) in self-stimulation were investigated by injecting directly or indirectly acting stimulant drugs or a dopamine-(DA)-receptor blocking agent into each site bilaterally. d-Amphetamine (68 nmol) facilitated hypothalamic self-stimulation when injected into either side. Apomorphine (40 nmol) depressed or facilitated responding, the direction and magnitude of this effect being contingent (C = 0.52) on the effect of systemic injection (0.3 mg/kg.i.p.), and correlated with the difference between the effects of d- and l-amphetamine (0.5 mg/kg i.p.) but not with injection site. Haloperidol (6.6 nmol) in either site depressed self-stimulation. Tyramine (730 nmol), an agent believed to cause noncontingent displacement of transmitter from catecholamine terminals, depressed self-stimulation when injection into CPU, but facilitated it when injected into ACB. The site-specific effects found with tyramine but not with apomorphine may have been due to release by tyramine of transmitters other than DA.
D000661:Amphetamine / Q000494:pharmacology; D000818:Animals; D001058:Apomorphine / Q000494:pharmacology; D003342:Corpus Striatum; D003913:Dextroamphetamine / Q000494:pharmacology; D004298:Dopamine / Q000502:physiology*; D006220:Haloperidol / Q000494:pharmacology; D007031:Hypothalamus / Q000502:physiology*; D007267:Injections; D008297:Male; D009714:Nucleus Accumbens; D051381:Rats; D012653:Self Stimulation / Q000187:drug effects*; D009435:Synaptic Transmission / Q000187:drug effects*; D014439:Tyramine / Q000494:pharmacology
D000661:Amphetamine; D006220:Haloperidol; D001058:Apomorphine; D003913:Dextroamphetamine; D004298:Dopamine; D014439:Tyramine