ETHANOL SENSITIVITY AND SUBUNIT COMPOSITION OF NMDA RECEPTORS IN CULTURED STRIATAL NEURONS

Assessment of ethanol (EtOH) sensitivity was combined with analysis of N-methyl-D-aspartate (NMDA) NR1-NR2 subunit composition in primary cu ltured striatal neurons. Subunit composition was determined by western blot analysis; assessment of ifenprodil and spermine sensitivity duri ng whole-cell patch-clamp recordings. From 3-21 days in culture, NR2B was the only NR2 subunit detected using NR2 subunit specific antibodie s; NMDA-induced currents were strongly inhibited by the NR2B-selective antagonist ifenprodil. Two populations of neurons were identified at arl ages in culture: those in which NMDA-induced current was or was no t potentiated by 100 mu M spermine. This suggested that the striatal n eurons expressed functional NMDARs which lacked or contained the NR1 N -terminal cassette. The EtOH sensitivity did not differ between these two populations of neurons nor did it change with age in culture at al l concentrations of EtOH studied. Human embryonic kidney (HEK) 293 cel ls containing NR1-1a or NR1-1b with either the NR2A or NR2B subunits d id not differ in their EtOH sensitivity. Thus, it would appear that th e presence or absence of the N-terminal cassette does not affect the E tOH sensitivity of recombinant NMDARs and native NMDARs expressed in c ultured striatal neurons. (C) 1998 Elsevier Science Ltd. All rights re served.