title: Effect of pinealectomy and melatonin on vasopressin-potentiated passive avoidance in rats.
abstract: The pineal indoleamine, melatonin, and the hypothalamic neuropeptide, vasopressin, facilitate passive avoidance behaviour in rats. The similarity of the effects suggest that interaction might occur between the two substances. Therefore, the effect of intraperitoneally applied vasopressin and/or melatonin on one-trial learning passive avoidance behaviour was studied in pinealectomized rats. Intraperitoneal treatment with 500 ng vasopressin 1 hr before the retention test increased passive avoidance latency of sham-operated rats. In pinealectomized rats, an identical amount of vasopressin was ineffective. In sham-operated rats, melatonin blocked the effect of vasopressin. It is concluded that vasopressin needs a regulated pineal function for developing effects in passive avoidance behaviour.
authors.affiliation: Department of Pathophysiology, Medical University of Lodz, Poland.
authors.forename: M
authors.initials: M
authors.lastname: Juszczak
authors.forename: J
authors.initials: J
authors.lastname: Drobnik
authors.forename: J W
authors.initials: JW
authors.lastname: Guzek
authors.forename: H
authors.initials: H
authors.lastname: Schwarzberg
mesh_terms: D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects* / Q000502:physiology; D008297:Male; D008550:Melatonin / Q000494:pharmacology*; D010870:Pineal Gland / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D014667:Vasopressins / Q000494:pharmacology*
chemical_list: D014667:Vasopressins; D008550:Melatonin