Modulation of memory retrieval by pre-testing vasopressin: involvement of a central cholinergic nicotinic mechanism.
Lysine vasopressin (LVP, 0.003-1.0 mcg/kg, s.c.) and the central acting nicotinic cholinergic agonist nicotine (N, 1.0-30.0 mcg/kg, s.c.) enhanced, whereas the vasopressin receptor antagonist 1-beta-mercapto-beta, beta-cyclopentamethylenepropionic acid-2-(O-methyl)tyrosine, arginine vasopressin (AAVP, 0.01-0.3 mcg/kg, s.c.) impaired retention test performance on a one-trial step-through inhibitory avoidance task when injected into male Swiss mice 20 min before the retention test. Tests were done 48 h following training. In all cases, the effects on retention test performance were dose-dependent. Neither LVP, N nor AAVP when given prior to testing modified latencies to step-through of mice that had not received a footshock during training. These findings suggest that LVP, N and AAVP influence memory retrieval processes. The effect of LVP on memory retrieval was antagonized by the simultaneous administration of AAVP (0.01 mcg/kg, s.c.) or mecamilamine (5 mg/kg, s.c.), but not by hexamethonium (5 mg/kg, s.c.), atropine (0.5 mg/kg, s.c.) or methylatropine (0.5 mg/kq, s.c.). On the contrary, the effect of N was only prevented by mecamilamine (5 mg/kg, s.c.). These results suggest a modulatory role of vasopressin on the activity of central cholinergic nicotinic mechanisms which are critical for memory retrieval.
Faiman
C P
CP
Dept. of Pharmacology, Faculty of Pharmacy and Biochemistry, University of Buenos Aires, Argentina.
de Erausquin
G A
GA
Baratti
C M
CM
D000818:Animals; D001127:Arginine Vasopressin / Q000031:analogs & derivatives / Q000494:pharmacology; D001362:Avoidance Learning / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004597:Electroshock; D005731:Ganglionic Stimulants / Q000494:pharmacology*; D008236:Lypressin / Q000494:pharmacology; D008297:Male; D008568:Memory / Q000187:drug effects*; D051379:Mice; D009538:Nicotine / Q000494:pharmacology; D010275:Parasympathetic Nervous System / Q000502:physiology*; D010276:Parasympatholytics / Q000494:pharmacology; D017483:Receptors, Vasopressin / Q000187:drug effects; D014667:Vasopressins / Q000037:antagonists & inhibitors / Q000494:pharmacology*
D005731:Ganglionic Stimulants; D010276:Parasympatholytics; D017483:Receptors, Vasopressin; D014667:Vasopressins; D001127:Arginine Vasopressin; D008236:Lypressin; D009538:Nicotine; C025043:vasopressin, 1-(1-mercaptocyclohexaneacetic acid)-2-(O- methyl-L-tyrosine)-8-L-arginine-