The main goal of the present study was to investigate the effects of ethanol on phase locking of EROs in order to give further insight into the actions of ethanol on the brain. Although a number of studies have presented data suggesting that phase locking of EROs is correlated with various cognitive functions, few studies have accomplished psychopharmacological studies using this methodology. In the present study phase locking to the rare (target) tone in the delta, theta, alpha, beta and gamma frequencies, within and between brain sites, was found at one hour following ethanol was significantly reduced as compared to placebo administration in both rats and humans. Two other studies have reported changes in brain synchrony following pharmacological challenge. In one study, administration of cholinergic antagonists was found to reduce interregional phase synchronization in humans (Wink et al., 2006). In another study, muscarinic blockade was shown to reduce the interaction between theta phase and gamma amplitude in the mouse (Hentschke et al., 2007). The results of these studies have been interpreted as indicating that phase synchronization may play a causal
