The NMDA receptor antagonist MK-801 produces ethanol-like discrimination in the rat

• Published in: Alcohol (Fayetteville, N.Y.) Vol. 10; no. 3; p. 197
• Main Authors: Schechter, M D, Meehan, S M, Gordon, T L, McBurney, D M
• Format: Journal Article
• Language: English
• Published: United States 01-05-1993
• Subjects: Animals; Discrimination Learning - drug effects; Dizocilpine Maleate - pharmacology; Ethanol - pharmacology; Rats; Receptors, N-Methyl-D-Aspartate - physiology
• ISSN: 0741-8329
• DOI: 10.1016/0741-8329(93)90035-M

Two groups of rats, one derived from N/Nih stock and the second from the (putatively) serotonin-compromised Fawn-Hooded line, were trained to discriminate ethanol from its vehicle in a drug discrimination paradigm. Once each of the two groups attained discrimination criterion, dose-response relationships with lower doses of ethanol indicated that the Fawn-Hooded rats were less sensitive (ED50 value = 579.5 mg/kg) than the N/Nih rats (ED50 = 371.4 mg/kg). Testing of various doses of the NMDA (N-methyl-D-aspartate) receptor antagonist MK-801 produced complete generalization in each group of animals, with a similar difference in ED50 values between N/Nih and Fawn-Hooded lines. These results extend previous ethanol-to-MK-801 generalization reported in pigeon, and are discussed in light of a possible NMDA-mediated contribution to the ethanol-induced discriminative stimulus cues.