Ethanol potentiates and blocks NMDA‐activated single‐channel currents in rat hippocampal pyramidal cells

FEBS Letters

Lima-Landman, Maria Teresa R.¹  Albuquerque, Edson X.¹ 

[1] Department of Pharmacology and Experimental Therapeutics, University of Maryland, School of Medicine, Baltimore, MD 21201, USA

关键词: Methyl-D-aspartate;    N-;    Single-channel current;    Ethanol effect;    (Hippocampus);    FDUR;    fluoro-2′-deoxyuridine;    NMDA;    N-methyl-D-aspartate;    p open;    probability of opening;   

DOI  :  10.1016/0014-5793(89)81241-4

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Single-channel currents activated by N-methyl-D-aspartate (NMDA) were characterized using the outside-out patch clamp technique in cultured hippocampal cells from the rat. Several conductance states were observed, and the main one of 47 pS was further analysed for channel lifetime and frequency. Open times decreased with hyperpolarization of the membrane. In view of recent evidence linking NMDA receptors to central nervous system processes such as learning and memory and ethanol (EtOH) tolerance, the effects of EtOH (0.01–1%, v/v, or ⋍ 1.74–174 mM) were studied in this preparation. Two effects of EtOH could be discerned: (i) at low concentrations (1.74–8.65 mM) an increase in the probability of opening (p _open) of the NMDA-activated channel currents, without change in the mean channel open time, and (ii) at higher concentrations (86.5–174 mM) a decrease in p _open with a concomitant decrease in the mean open time. It is suggested that EtOH, even at rather low concentrations, may affect important brain functions.

【 授权许可】

Unknown