The overall goal of this research program is to utilize electrophysiological measures, specifically waking EEG, event-related potentials (ERPs), and measures of the sleep EEG to explore the neural substrates which underlie alcohol’s abuse liability. Our studies, as well as others, suggest in human subjects that specific ERP and sleep/waking EEG measures may be particularly valuable in: 1) characterizing risk for the future development of alcoholism 2) exploring individual differences in acute response to ethanol and 3) quantifying the effects of chronic ethanol exposure/relapse to drinking. The newly proposed studies will use electrophysiological measures to further explore the functional activity of specific brain sites identified in previous studies, a neural circuit that includes frontal cortex, the extended amygdala and the hypothalamus, with ethanol self-administration. Neuropharmacological studies will be aimed at further understanding neuropeptide modulation of alcohol consumption as well as the effects of ethanol exposure on electrophysiological measures of sleep and behavior. The overall goals of the current research program will be accomplished through the following specific aims: AIM 1: To continue to develop clinically relevant electrophysiological and behavioral measures in rodents which are informative assays of brain differences between rodent lines that differ in ethanol preference. AIM 2: To investigate functional brain electrophysiology in discrete cortical and subcortical areas during ethanol self-administration with a focus on determining specific peptidergic influences on alcohol consumption patterns. AIM 3: To determine the consequences of chronic ethanol exposure on electrophysiology in rodents with a specific focus on neurophysiological changes during sleep and their relation to relapse. The use of these electrophysiological measures, combined with neurochemical findings will provide data necessary to directly link these peptidergic systems to alcohol preference and long term neuroadaption to alcohol.