Learning and memory in agmatine-treated rats

• Published in: Pharmacology, biochemistry and behavior Vol. 72; no. 3; pp. 551 - 557
• Main Authors: McKay, B.E, Lado, W.E, Martin, L.J, Galic, M.A, Fournier, N.M
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01-06-2002; Elsevier Science
• Subjects: Agmatine; Agmatine - pharmacology; Aminoacid receptors (glycine, glutamate, gaba); Animals; Avoidance Learning - drug effects; Avoidance Learning - physiology; Biological and medical sciences; Cell receptors; Cell structures and functions; Conditioned taste aversion; Contextual fear; Discrete fear; Dose-Response Relationship, Drug; Fear - drug effects; Fear - physiology; Female; Fundamental and applied biological sciences. Psychology; Learning - drug effects; Learning - physiology; Learning. Memory; Male; Maze Learning - drug effects; Maze Learning - physiology; Memory - drug effects; Memory - physiology; Miscellaneous; Molecular and cellular biology; N-Methylaspartate - antagonists & inhibitors; Place learning; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Rat; Rats; Rats, Wistar; Taste - drug effects; Taste - physiology; Conditioned taste aversion; Discrete fear; Rat; Place learning; Agmatine; Contextual fear; Memory disorder; Intraperitoneal administration; Cognitive disorder; Metabolite; Toxicity; Memory; Instrumental conditioning; Endogenous substance; Cognition; Glutamate receptor; Learning; Acquisition process; Arginine; Learning disability; Central nervous system disease; Antagonist; Glutamatergic transmission; Conditioned aversion; NMDA receptor
• ISSN: 0091-3057; 1873-5177
• DOI: 10.1016/S0091-3057(02)00724-4

Agmatine, a noncompetitive
N-methyl-
d-aspartate (NMDA) antagonist, was examined for its role in water maze place learning, contextual and auditory-cued (discrete) fear learning and conditioned taste aversion learning, when administered systemically. Male Wistar rats were given saline or 1, 5, 10 or 50 mg/kg agmatine ip 20 min prior to or 30 min following daily training sessions in a hidden-platform (place learning) water maze task. Agmatine did not affect latencies to find the hidden platform or preference for the training quadrant during probe trials. When administered 20 min prior to contextual or auditory-cued fear-conditioning sessions, these doses of agmatine evoked a linear dose-dependent impairment in the magnitude of learned fear to the contextual stimuli when assessed during extinction trials 24 h later, but had no effect on the magnitude of learned fear to the auditory stimulus. Inferences of baseline motor activity and ability to respond to the presentation of footshock stimuli were not affected by the treatment. Injections of 50 mg/kg agmatine concurrently with a malaise-evoking agent following presentations to a novel sucrose solution abolished learned taste aversions; this agent did not evoke conditioned taste aversions alone. These studies indicate that systemically administered agmatine selectively impairs behavioral inferences of specific types of learning and memory.