Self-stimulation and local injections of 6-hydroxydopamine into the rat brain: enhanced behavioral depressive effects of alpha-methylparatyrosine.
The effects of intracerebral injections of 6-OHDA on self-stimulation were examined. Small amounts of 6-OHDA were injected either in the area ventralis tegmenti (AVT) or laterally in the pedonculus cerebellaris superior (PCS), then all rats were implanted in the AVT. In spite of marked depletion of brain catecholamines, self-stimulation learning was not altered by PCS 6-OHDA injections, whereas, AVT 6-OHDA injections produced a small perturbance. The administration of low doses of AMPT which had no observable effect in control rats, produced a severe depression of self-stimulation rates in 6-OHDA pretreated rats. The depressive effect of AMPT is always more important in rats injected with 6-OHDA in the AVT than those injected at the level of PCS. The respective role of noradrenergic and dopaminergic neurons in AVT self-stimulation are discussed.
D000818:Animals; D001921:Brain / Q000187:drug effects / Q000502:physiology; D004597:Electroshock; D006892:Hydroxydopamines / Q000494:pharmacology*; D007267:Injections; D007858:Learning / Q000187:drug effects*; D008297:Male; D008781:Methyltyrosines / Q000494:pharmacology*; D009928:Organ Specificity; D051381:Rats; D012653:Self Stimulation; D013997:Time Factors
D006892:Hydroxydopamines; D008781:Methyltyrosines