Vasopressin modulates the activity of catecholamine containing neurons in specific brain regions.

Following the i.c.v. administration of antivasopressin serum the alpha-MPT-induced disappearance of noradrenaline was decreased in the dorsal septal nucleus, parafascicular nucleus and the rostral part of the nucleus tractus solitarii, whereas that of dopamine was lowered in the caudate nucleus and in the A2 region of the medulla oblongata. In general the effects are opposite to those previously found following the i.c.v. administration of vasopressin. The results support the hypothesis that vasopressin modulates catecholamine neurotransmission in specific brain regions of the rat.