The role of the lateral habenula circuitries in alcohol use disorders

The aversive consequences of withdrawal from chronic alcohol abuse are risk factors for relapse drinking and alcoholism, but the underlying neuronal mechanisms are not well-understood. Accumulating evidence suggests that the lateral habenula (LHb), an epithalamic structure that connects the forebrain with the midbrain may play a crucial role. This chapter centers on the recent evidence about the effects of alcohol on the activity and synaptic transmissions of the LHb. Multidisciplinary work in rodents collectively suggests that acute and repeated alcohol exposure increases the strength of excitatory synapses and excitability of LHb neurons, which is concomitant with the affective psychiatric behaviors occurring during alcohol withdrawal. We also review evidence about the amelioration of relapse drinking and psychiatric disorders in withdrawal animals through LHb inhibition. These findings highlight a critical role for the LHb and its circuits in alcohol use disorder and related psychiatric ailments.