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Title: Ethanol (EtOH) inhibition of NMDA-activated ion current is not voltage-dependent and EtOH does not interact with other binding sites on the NMDA receptor/ionophore complex

Conference · · FASEB Journal (Federation of American Societies for Experimental Biology); (United States)
OSTI ID:6058497
; ;  [1]
  1. National Inst. of Alcohol Abuse and Alcoholism, Rockville, MD (United States)

Recent studies indicate that intoxicating concentrations of EtOH inhibit neuronal responses to activation of NMDA-type glutamate receptors. The authors have observed that the potency of different alcohols for inhibiting NMDA-activated ion current in hippocampal neurons increases as a function of increasing hydrophobicity, suggesting that EtOH acts at a hydrophobic site. To further characterize the mechanisms of this effect, the authors examined the voltage-dependence of the EtOH inhibition of NMDA-activated ion current as well as potential interactions of EtOH with other effectors of the NMDA receptor/ionophore complex. The amount of inhibition of peak NMDA-activated current by 50 mM EtOH did not differ over a range of membrane potentials from {minus}60 to +60 mV, and EtOH did not alter the reversal potential of NMDA-activated current. The percent inhibition observed in the presence of 10-100 mM EtOH did not differ with NMDA concentrations from 10-100 {mu}M. The percent inhibition by 50 mM EtOH (30-48%) did not differ in the absence or presence of the channel blockers Mg{sup 2+} (50-500 {mu}M), Zn{sup 2+} (5 and 20 {mu}M) or ketamine (2 and 10 {mu}M), or with increasing concentrations of the NMDA receptor cofactor glycine (0.01-1 {mu}M). These data indicate that: (i) EtOH does not change the ion selectivity of the ionophore, and (ii) EtOH does not appear to interact with previously described binding sites on the NMDA receptor/ionophore complex.

OSTI ID:
6058497
Report Number(s):
CONF-9104107-; CODEN: FAJOE
Journal Information:
FASEB Journal (Federation of American Societies for Experimental Biology); (United States), Vol. 4:3; Conference: 75. annual meeting of the Federation of American Societies for Experimental Biology (FASEB), Atlanta, GA (United States), 21-25 Apr 1991; ISSN 0892-6638
Country of Publication:
United States
Language:
English