Recruitment of medial prefrontal cortex neurons during alcohol withdrawal predicts cognitive impairment and excessive alcohol drinking

Abstract

Chronic intermittent access to alcohol leads to the escalation of alcohol intake, similar to binge drinking in humans. Converging lines of evidence suggest that impairment of medial prefrontal cortex (mPFC) cognitive function and overactivation of the central nucleus of the amygdala (CeA) are key factors that lead to excessive drinking in dependence. However, the role of the mPFC and CeA in the escalation of alcohol intake in rats with a history of binge drinking without dependence is currently unknown. To address this issue, we examined FBJ murine osteosarcoma viral oncogene homolog (Fos) expression in the mPFC, CeA, hippocampus, and nucleus accumbens and evaluated working memory and anxiety-like behavior in rats given continuous (24 h/d for 7 d/wk) or intermittent (3 d/wk) access to alcohol (20% vol/vol) using a two-bottle choice paradigm. The results showed that abstinence from alcohol in rats with a history of escalation of alcohol intake specifically recruited GABA and corticotropin-releasing factor (CRF) neurons in the mPFC and produced working memory impairments associated with excessive alcohol drinking during acute (24-72 h) but not protracted (16 -68 d) abstinence. Moreover, abstinence from alcohol was associated with a functional disconnection of the mPFC and CeA but not mPFC and nucleus accumbens. These results show that recruitment of a subset of GABA and CRF neurons in the mPFC during withdrawal and disconnection of the PFC-CeA pathway may be critical for impaired executive control over motivated behavior, suggesting that dysregulation of mPFC interneurons may be an early index of neuroadaptation in alcohol dependence.A lcoholism is a chronic relapsing disorder associated with compulsive drinking, loss of control over intake, and emergence of a negative emotional state during abstinence from the drug (1). Although no known animal model of addiction fully emulates the condition in humans, some models are better suited for the investigation of specific elements of the addiction process in a clinically relevant manner. Recently, an animal model of alcohol binge drinking with good face and predictive validity for what may be considered a transition to alcoholism has been reintroduced (2, 3). Rats given extended (24 h/d) and intermittent (every other day) choice access to ethanol escalate their intake of alcohol over the course of 2-4 wk in a binge-like pattern (2-6), and alcohol drinking using this paradigm was reduced by two drugs approved by the US Food and Drug Administration for the treatment of alcoholism (i.e., naltrexone and acamprosate) (2). Moreover, escalation of alcohol drinking using this model is associated with decreased dopamine levels in the nucleus accumbens after 24 h of abstinence (7), decreased endocannabinoid signaling in the dorsolateral striatum (8), and activation of FBJ murine osteosarcoma viral oncogene homolog B (ΔFosB) in the nucleus accumbens core, dorsolateral striatum, and orbitofrontal cortex.Converging lines of evidence from human and animal studies suggest that impairm...

Subgroup-dependent effects of voluntary alcohol intake on behavioral profiles in outbred Wistar rats

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Animal models of post-traumatic stress disorder and recent neurobiological insights

“…These data support the further use and development of noradrenergic agents for the treatment of PTSD, and are in strong accordance with the demonstrated efficacy of prazosin in both preclinical models (Olson et al , 2011) and PTSD patient populations (Raskind et al , 2003) (Krystal and Neumeister, 2009). Finally, excessive alcohol exposure and dependence itself may contribute to dysregulated signaling in the PFC (George et al , 2012; Kim et al , 2014), leading to the development or exacerbation of PTSD-associated symptoms in rodents (Holmes et al , 2012), consistent with the human literature (Tipps et al , 2014; Perrin et al , 2014). …”

Alcohol, stress hormones, and the prefrontal cortex: A proposed pathway to the dark side of addiction

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