PMC

Changes in mIPSC τ_d during acute application of 50 mM ethanol are shown for age-matched control neurons (gray bars) and for hippocampal neurons cultured in the presence of 50 mM ethanol for 1 or 5 days (open bars). Acute application of ethanol increased mIPSC τ_d in control neurons 15-16 days in vitro but not in older control neurons or ethanol treated neurons. † p < 0.05 by paired t-test comparing acute ethanol exposure to pre-drug baseline.

Representative tracings of voltage-clamp recordings from cultured cortical neurons under baseline conditions and during acute exposure to 20 μM flurazepam (A) or 50 mM ethanol (B) in the extracellular solution. A and B are shown at the same scale. Scale bars: x = 1s, y = 10 pA. Mean changes in mIPSC amplitude (C), rise time (D), decay time constant (E), and interevent interval (F) during exposure to 20 μM flurazepam (black bars) or 50 mM ethanol (gray bars) relative to the no-drug baseline. † p < 0.05 by paired t-test. Scaled and averaged mIPSCs under baseline conditions and during exposure to flurazepam (G) or ethanol (H).

Beginning at 14 or 15 days in vitro, hippocampal neurons were cultured in the absence (gray bars) or presence (open bars) of 50 mM ethanol in the tissue culture medium. Average mIPSC amplitude (A), rise time (B), decay time constant (C), and interevent interval (D) are shown for age-matched controls and neurons treated with ethanol for 1 to 5 days. Ethanol treatment did not alter mIPSC amplitude, kinetics, or frequency.

Representative tracings of voltage-clamp recordings from cultured hippocampal neurons aged 15-16 days in vitro under baseline conditions and during acute exposure to 20 μM flurazepam (A) or 50 mM ethanol (B) in the extracellular solution. A and B are shown at the same scale. Scale bars: x = 1s, y = 10 pA. Mean changes in average mIPSC amplitude (C), rise time (D), decay time constant (E), and interevent interval (F) during exposure to 20 μM flurazepam (black bars) or 50 mM ethanol (gray bars) relative to the no-drug baseline are shown. † p < 0.05, †† p < 0.01 by paired t-test. Scaled and averaged mIPSCs under baseline conditions and during exposure to flurazepam (G) or ethanol (H).

Both cortical (A) and hippocampal neurons (B) were cultured in the absence (gray bars) or presence (open bars) of 50 mM ethanol in the tissue culture medium. The increase in mIPSC τ_d during acute application of 20 μM flurazepam in the external solution is shown. (A) Cultured cortical cells 19-20 days in vitro were less sensitive to flurazepam than control neurons 15-16 days in vitro. Chronic ethanol exposure did not alter mIPSC sensitivity to flurazepam at either timepoint. p < 0.05 ANOVA. * p < 0.05 compared to control 15-16 DIV by Holm-Sidak post-hoc test, † p < 0.05 compared to pre-drug baseline by paired t-test. (B) In cultured hippocampal neurons, flurazepam significantly increased mIPSC τ_d in control cells 15-16 and 19-20 days in vitro. Ethanol treatment for 1 or 5 days did not alter mIPSC flurazepam sensitivity. † p < 0.05, †† p < 0.01 compared to pre-drug baseline by paired t-test.

Cultured neurons aged 14 days in vitro were exposed to 50 mM ethanol in the tissue culture medium for 1 to 7 days. A. Averaged mIPSCs for a control neuron and a neuron exposed to 50 mM ethanol for 24 hours. B. Percent change in average mIPSC decay time constant calculated relative to age and culture matched controls for neurons exposed to 50 mM ethanol for 1,2, or 3 days. †† p < 0.005 compared to controls by paired t-test. C. Absolute values for mIPSC decay time constants in ethanol treated neurons and controls. One day of ethanol treatment decreased mIPSC τ_d from 32.7±1.7 ms in control cells to 26.2±1.0 ms in ethanol treated cells. † p < 0.05 by Holm-Sidak posthoc test.