Changes in the structural morphology and integrity of the PFC have also been observed that may underlie the cognitive deficits associated with chronic alcohol exposure. Alcohol-dependent subjects show reduced gray matter in the dorsolateral PFC (Jernigan et al., 1991). Chronic alcohol use is associated with reduced white matter volume throughout the cortex (de la Monte, 1988). Frontal lobes seem to be especially susceptible to volume loss following long-term chronic alcohol exposure (Pfefferbaum et al., 1997). Reductions in levels of N-acetylaspartate, an abundant CNS metabolite, have also been observed in prefrontal white matter of detoxified alcoholic subjects (Schweinsburg et al., 2001), perhaps indicating an atrophy of white matter during withdrawal. Additionally, the integrity of white matter in the right orbitofrontal cortex is significantly impaired in chronic alcoholics (Pfefferbaum and Sullivan, 2005; Harris et al., 2008). A study using stereology to monitor cell number demonstrated no significant cell loss through the neocortex, even though overall cortical volume was decreased, suggesting atrophy or dendritic retraction rather than frank cell death (Jensen and Pakkenberg, 1993). Significant reduction of soma size in frontal cingulate cortex
