Melanin-concentrating hormone, hippocampal nitric oxide levels and memory retention

• Published in: Peptides (New York, N.Y. : 1980) Vol. 23; no. 12; pp. 2213 - 2221
• Main Authors: Varas, Mariana, Pérez, Mariela, Monzón, Marı́a Elena, de Barioglio, Susana Rubiales
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.12.2002
• Subjects: Animals; Behavior; Behavior, Animal - physiology; cGMP; Cyclic GMP - metabolism; Electrophysiology; Hippocampus; Hippocampus - metabolism; Hypothalamic Hormones - metabolism; Male; MCH; Melanins - metabolism; Memory - physiology; Nitric oxide; Nitric Oxide - metabolism; Nitric Oxide Synthase - antagonists & inhibitors; Pituitary Hormones - metabolism; Rats; Rats, Wistar; Synaptic transmission; cGMP; MCH; Behavior; Synaptic transmission; Nitric oxide; Hippocampus
• ISSN: 0196-9781; 1873-5169
• DOI: 10.1016/S0196-9781(02)00252-8

The present study attempts to determine, if the effect of melanin-concentrating hormone (MCH) upon memory retention is correlated with changes in nitric oxide synthase (NOS) activity and tissue levels of nitric oxide (NO) and cGMP. We used a behavioral experiment using a step-down inhibitory avoidance test, the biochemical determinations of NO and cGMP, and electrophysiological model. Results of behavioral studies (step-down test) showed that MCH administration reverts the amnesic effects induced by N G-nitro- l-arginine ( l-NOArg). Moreover, electrophysiological studies demonstrated that l-NOArg did not block the potentiation induced by the peptide. Hippocampal NO and cGMP levels increased after MCH injection.