It is now apparent that acute and chronic ethanol exposure alters synaptic function and neuronal connectivity in a variety of brain regions, affecting multiple brain circuits. It does so by affecting both excitatory and inhibitory neurotransmission as well as altering the release of neuromodulators such as dopamine, opioids and likely also acetylcholine. It is reasonable to speculate that each of these direct and indirect actions of ethanol on the different brain circuits contributes to specific aspects of intoxication, ethanol seeking and drinking, and alcohol use disorders. In order to parse out their contributions, detailed knowledge of the specific cognitive and behavioral functions subserved by each of these brain circuits is needed. While significant progress has been made in this regard over the past decades, more work is needed for addressing the specific role of neuronal circuits and pathways, rather than nuclei as a whole. Moving forward, it is also crucial to improve our understanding of how the different circuits interact with each other to produce more complex behaviors such as the constellation of behavioral changes that follow ethanol use and abuse.
