Environmental enrichment may protect against neural and behavioural damage caused by withdrawal from chronic alcohol intake

Abstract

Exposure to stress and prolonged exposure to alcohol leads to neuronal damages in several brain regions, being the medial prefrontal cortex (mPFC) one of the most affected. These changes presumably reduce the ability of the organism to cope with these stimuli and may underlie a series of maladaptive behaviours among which include drug addiction and withdrawal. Drug-addicted individuals show a pattern of behavior similar to patients with lesions of the mPFC. This impairment in the decision-making could be one of the mechanisms responsible for the transition from the casual to compulsive drug use. The environmental enrichment (EE) has a protective effect on the neural and cognitive impairments induced by psychoactive drugs, including ethyl alcohol. The present study aims to determine the influence of withdrawal from intermittent long-term alcohol exposure on alcohol preference, emotional reactivity and neural aspects of early isolated or grouped reared rats kept under standard or complex environments and the influence of social isolation on these measures, as well. Our results point out new insights on this matter showing that the EE can attenuate the adverse effects of withdrawal and social isolation on rat’s behavior. This effect is probably due to its protective action on the mPFC integrity, including the cingulate area 1 (Cg1), and the prelimbic (PrL) and infralimbic cortex (IL), what could account for the absence of changes in the emotional reactivity in EE alcohol withdrawal rats. We argue that morphological changes at these cortical levels can afford the emotional, cognitive and behavioural dysregulations verified following withdrawal from chronic alcohol intake.