Oxytocin affects utilization of noradrenaline in distinct limbic-forebrain regions of the rat brain

Abstract

Summary-The effects of oxytocin, administered intracerebroventricularly in doses of 1, 10, 100 and IOOOpmol, were studied on the disappearance of catecholamines induced by a-methyl-p-tyrosine in microdissected nuclei of the rat brain. Oxytocin dose-dependently decreased the utilization of noradrenaline in the lateral and medial septal nuclei and anterior hypothalamic area, whereas an enhanced utilization was observed in the nucleus supraopticus. Tendency towards a change in utilization of noradrenaline was found in the dorsal septal nucleus and the lateral amygdala. Utilization of dopamine was not significantly affected in any of the nuclei of the brain studied. Tendency towards a decrease in utilization of dopamine was observed in the nucleus caudatus, globus pallidus and medial septal nucleus. It thus appears that oxytocin elicited changes in only a restricted number of brain nuclei. Interestingly, these nuclei contain cell bodies (nucleus supraopticus) and terminals (other nuclei) of the oxytocin system in the brain. Though the effects of oxytocin were not as widespread as those previously seen after administration of vasopressin, it is worthy of note that, in general, the effects of oxytocin were opposite to those seen after vasopressin. The opposite effecs of vasopressin and oxytocin on catecholamine metabolism could be related to the opposite effects of the two peptides on behaviour, neuroendocrine and autonomic regulation.

Vasopressin (DDAVP) Therapy in Chronic Schizophrenia: Effects on Negative Symptoms and Memory

“…In experimental animals, a stimulatory effect of vaso pressin on the DA system in specific brain areas has been reported [Van Heuven-Nolsen et al, 1984], In our pa tients, we observed, if anything, a trend toward a de crease of plasma HVA levels. This recalls the results of Pickaret al [1984,1985,1986], who found that in their schizophrenics there was a significant correlation be tween decrease of HVA and improvement of positive negative symptomatology after neuroleptic therapy.…”