MTOR and Brain atrophy: The investigations clearly delineated the effects of early and short-term versus long-term chronic effects of heavy alcohol exposure in that the early period in which brain atrophy and white matter myelin loss were minimal was associated with activation of oligodendrocyte and insulin/IGF/Akt-mTOR pathways, whereas the chronic phase, coinciding with brain atrophy and white matter degeneration, was marked by impaired signaling through mTOR.