Similar to previous reports (Traub et al., 2004), kainate (200 nM) induced persistent γ oscillations in the CA3 area of rat hippocampal brain slices. The γ oscillation normally took 50–120 min to reach a steady state and was then stable for hours. When the steady state was reached, a baseline measure of γ power and peak frequency was taken as the average of 5 min before various concentrations of ethanol (5–100 mM) were added to the ACSF. At 5 mM ethanol had no effect on γ oscillations (106.3 ± 7.0% of base line γ power, P > 0.05, n = 12). Ethanol caused a small increase in γ power at 10 mM (117.4 ± 6.2% of baseline, P < 0.05, n = 11), but reduced γ power at concentrations ≥25 mM (Figures 1A–C) in a dose-dependent manner (Figure 1D). Upon washout of ethanol, γ power recovered partially or fully (Figure 1C). On average, ethanol suppressed γ power by 19.4 ± 5.3% (P < 0.05, n = 8) at 25 mM, by 32.6 ± 4.6% (P < 0.01, n = 8)
