Our study shows that ethanol (10 mM) increased γ power without affecting the peak frequency, suggesting that at a low concentration, ethanol may increase network activity. Because IPSCs are crucial for γ oscillations (Cunningham et al., 2003), the enhancement of γ oscillations at low ethanol concentrations can be ascribed to increased phasic IPSC amplitudes (Wan et al., 1996). This is somewhat similar to a recent report that showed ethanol (15 mM) increased peak γ amplitude in human primary visual and motor cortex (Campbell et al., 2014). However, such an increase in γ power is limited in amplitude and is only observed in a narrow range of ethanol concentrations in this study.
