Abuse of alcohol is associated with a high incidence of accidents and violence. The occurrence of injuries to the head and brain including penetrating wounds, lacerations and contusions is well documented. Key responses of the central nervous system to trauma encompass reactive differentiation and proliferation of astrocytes; these reactions are mediated by tissue-derived factors. The overall objective of the proposed work is to identify the extent to which ethanol exposure alters the participation of astrocytes in the process of healing and repair of cerebral tissue. Under the present proposal, several studies will be initiated: 1) to characterize the influence of ethanol administration on the reactive changes in cerebral tissue following a standardized needle penetration injury, and 2) to investigate the mechanisms of interaction between ethanol and injury-induced tissue mitogens. A comprehensive morphologic characterization of ethanol-related effects is planned to assess changes in vascular and glial tissue components in the vicinity of the traumatized tissue after a ten day reparative period. Standard light microscopy, immunocytochemistry and electron microscopy are to be used to provide benchmark information required for interpretation of concurrent tissue culture studies. Extracts of traumatized cerebral tissue contain a potent mitogen which has been suggested to stimulate the proliferation of astrocytes subsequent to tissue injury. Extensive use of astrocytic cultures is planned to address two issues: 1) does systemic ethanol-treatment alter the elaboration of injury-induced mitogen, 2) does acute or chronic exposure of astrocytes to ethanol in culture alter the responses of these cells to mitogens. Tissue-extracts from ethanol treated and control animals are to be compared for mitogenic activity in astrocytic cultures characterized by the presence of polygonal cells and glial fibrillary of acidic protein immunoreactivity. Flow cytometry will be used to study the interaction of ethanol-exposure and tissue mitogens. Additionally, the effects of direct exposure of astrocytes to ethanol at two dose levels will be evaluated following acute (24 hr) and chronic (60 days) treatment. The cultures are to be evaluated for glial fibrillary acidic protein immunoreactivity, ultrastructural, and neurotrophic properties. The responses of these cells to injury-induced mitogen and myelin basic protein are to be examined with flow cytometry.
