Ethanol inhibition of NMDA mediated depolarizations is increased in the presence of Mg2+.

Published

Journal Article

The inhibitory potency of ethanol upon excitatory amino acid induced depolarizations of rat hippocampal CA1 pyramidal cells was assessed in the presence and absence of magnesium (Mg2+) using the grease-gap technique. Ethanol shifted the N-methyl-D-aspartate (NMDA) dose-response curves to the right in a non-parallel manner. In the presence of Mg2+, ethanol appeared to be a more effective NMDA antagonist (IC50 47 mM) than in the absence of Mg2+ (IC50 107 mM). The IC50 for ethanol upon non-NMDA mediated CA1 pyramidal cell depolarizations was in excess of 170 mM. These results strongly suggest a preferential inhibitory action of ethanol against NMDA, rather than non-NMDA, mediated responses. Experiments in which ethanol and Mg2+ were covaried indicated that these substances act by two distinct mechanisms to antagonize the action of NMDA. These effects of ethanol, at concentrations which elicit intoxication (less than 50 mM) but not anesthesia, suggest that the NMDA receptor complex may play an important role in the acute effects of ethanol.

Full Text

Duke Authors

Cited Authors

  • Martin, D; Morrisett, RA; Bian, XP; Wilson, WA; Swartzwelder, HS

Published Date

  • April 19, 1991

Published In

Volume / Issue

  • 546 / 2

Start / End Page

  • 227 - 234

PubMed ID

  • 2070260

Pubmed Central ID

  • 2070260

International Standard Serial Number (ISSN)

  • 0006-8993

Digital Object Identifier (DOI)

  • 10.1016/0006-8993(91)91486-k

Language

  • eng

Conference Location

  • Netherlands