THE NEUROBIOLOGY OF ALCOHOLISM - RESULTS OF NEUROPATHOLOGICAL AND NEUROIMAGING STUDIES

The authors deal with the heuristic value of the ''neurobiological model of alcohol dependence''. It allows the study of the influence of a defined noxe on different brain structures. Additionally, it enables the quantification of regeneration and restitution processes in abstinence. Because of this, the alcoholism model goes beyond dementia, the model which has dominated brain research so far. Neuropathological studies in humans and animals found a reduction in the volume of white matter and a partial degeneration, or even loss of specific neurons. According to animal data, this could to a certain extent be genetically determined. Alcohol exerts a distinct influence on different neurotransmitter systems. This research will deepen our understanding of the neurotoxic and psychotropic properties of alcohol, and of the development of dependence. Little is known about the role of astrocytes in the reaction of the brain to alcohol. Here again, the neurobiological model of alcohol dependence could be of value in learning more about their interactions with neurons. Using Magnetic Resonance Imaging and CAT-scans, the decrease in volume of white and grey matter was demonstrated in vivo. The degree and the time course of brain damage seems to be influenced less by drinking history than by age and gender. There is evidence that female alcoholics develop brain damage more readily than men. When abstinent, an increase in the volume of white and grey matter can be observed. This is not due to the rehydration of brain tissue alone. Future research will need to deal with the question of whether the central nervous system is capable of partial regeneration. For the study of neuroplasticity, the neurobiological model of alcohol dependence seems to be particularly well suited.