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 of alcoholics, without a significant change in cell number, has also been observed (Kril et al., 1989). Changes in glial cell count following chronic ethanol exposure have also been reported and indicate decreases in both density and size of glia in dorsolateral PFC (Miguel-Hidalgo et al., 2002) and orbitofrontal cortex (Miguel-Hidalgo et al., 2006). Whether the loss of volume in PFC in alcohol-dependent subjects is reversible is still undetermined. In one study, subjects who were abstinent for 6–9 months after entering a rehab program showed decreased ventricle size, but there was no increase in frontal lobe volume when compared to their entry into the rehab program (Wobrock et al., 2009).
