No abstract

No abstract

No abstract

No abstract

We have previously reported that a 30 s ethanol (10 and 100 mM) pre-exposure significantly enhanced EtOH inhibition of N-methyl-d-aspartate-induced peak currents (INMDA) in primary cultured cerebellar granule cells (CGC)s. The purpose of this study was to determine if intracellular factors play a role in ethanol pre-exposure-enhanced inhibition of INMDA and if so, to identify the intracellular target(s) mediating this effect. Ethanol pre-exposure-enhanced inhibition was reduced when ethanol was present intracellularly prior to the initiation of the pretreatment protocol. Similar to results acquired with the whole-cell configuration, ethanol pre-exposure-enhanced inhibition of INMDA was also observed in the perforated patch (PP)-clamp mode. Collectively, these results suggest an intracellular target not easily dialyzed from the cell. That perturbation of the actin cytoskeleton was responsible for the ethanol pre-exposure-enhanced inhibition of INMDA was supported by the observation that the intracellular presence of the actin stabilizer phalloidin prevented ethanol pre-exposure-enhanced inhibition. Similar to the effects of ethanol, the depolymerizing agent latrunculin A inhibited INMDA after a 30 s pretreatment exposure with full recovery of receptor function after washout of the drug. Furthermore, latrunculin A occluded the enhanced inhibition of INMDA by ethanol pre-exposure for both 10 and 100 mM ethanol. The microtubule depolymerizing agent taxol had no affect on ethanol pretreatment-enhanced inhibition of INMDA. Confocal microscopy with phalloidin-FITC indicated that F-actin filaments in neurites were depolymerized after a 30 s treatment of either latrunculin A or 100 mM ethanol. Our observations indicate that ethanol inhibition of NMDAR function may involve perturbation of the actin cytoskeleton.