Reciprocal midbrain-extended amygdala circuit activity in preclinical models of alcohol use and misuse

• Published in: Neuropharmacology Vol. 202; p. 108856
• Main Authors: Avegno, Elizabeth M., Gilpin, Nicholas W.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01-01-2022
• Subjects: Adaptation, Psychological - physiology; Addiction; Alcohol; Alcohol Drinking - psychology; Alcoholism - etiology; Alcoholism - physiopathology; Alcoholism - psychology; Amygdala - physiology; Animals; Bed nucleus of stria terminalis; Central amygdala; Extended amygdala; Humans; Mesencephalon - physiology; Motivation; Neural Pathways - physiology; Nucleus accumbens; Reinforcement, Psychology; Ventral tegmental area; Ventral Tegmental Area - physiology; Nucleus accumbens; Central amygdala; Addiction; Bed nucleus of stria terminalis; Alcohol; Ventral tegmental area; Extended amygdala
• ISSN: 0028-3908; 1873-7064
• DOI: 10.1016/j.neuropharm.2021.108856

Alcohol dependence is characterized by a shift in motivation to consume alcohol from positive reinforcement (i.e., increased likelihood of future alcohol drinking based on its rewarding effects) to negative reinforcement (i.e., increased likelihood of future alcohol drinking based on alcohol-induced reductions in negative affective symptoms, including but not limited to those experienced during alcohol withdrawal). The neural adaptations that occur during this transition are not entirely understood. Mesolimbic reinforcement circuitry (i.e., ventral tegmental area [VTA] neurons) is activated during early stages of alcohol use, and may be involved in the recruitment of brain stress circuitry (i.e., extended amygdala) during the transition to alcohol dependence, after chronic periods of high-dose alcohol exposure. Here, we review the literature regarding the role of canonical brain reinforcement (VTA) and brain stress (extended amygdala) systems, and the connections between them, in acute, sub-chronic, and chronic alcohol response. Particular emphasis is placed on preclinical models of alcohol use.
This article is part of the special Issue on ‘Neurocircuitry Modulating Drug and Alcohol Abuse'.
∙We review the role of canonical midbrain reinforcement (VTA) and brain stress (extended amygdala) systems in commonly measured outcomes in preclinical alcohol use disorder (AUD) models∙We summarize what is and is not known about reciprocal circuits between midbrain and extended amygdala brain areas, broken down by cell type and sub-region∙We summarize what is and is not known about the effects of acute, sub-chronic, and chronic alcohol exposure on VTA-extended amygdala circuits and the role of those circuits in alcohol-related behaviors