Effects of six weeks of chronic ethanol administration on the behavioral outcome of rats after lateral fluid percussion brain injury

This study examined the effects of 6 weeks of chronic ethanol administratio n on the behavioral outcome in rats after lateral fluid percussion (FP) bra in injury. Rats were given either an ethanol liquid diet (ethanol diet-grou ps) or a pair-fed isocaloric sucrose control diet (control diet groups) for 6 weeks. After 6 weeks, the ethanol diet was discontinued for the ethanol diet rats and they were then given the control sucrose diet for 2 days. Dur ing those 2 days, the rats were trained to perform a beam-walking task and subjected fro either lateral FP brain injury of low to moderate severity (1 .8 atm) or to sham operation. In both the control diet and the ethanol diet groups, lateral FP brain injury caused beam-walking impairment on days 1 a nd 2 and spatial learning disability on days 7 and 8 after brain injury. Th ere were no significant differences in beam-walking performance and spatial learning disability between brain injured animals from the control and eth anol diet groups. However, a trend towards greater behavioral deficits was observed in brain injured animals in the ethanol diet group. Histologic ana lysis of both diet groups after behavioral assessment revealed comparable i psilateral cortical damage and observable CA(3) neuronal loss in the ipsila teral hippocampus. These results only suggest that chronic ethanol administ ration, longer than six weeks of administration, may worsen behavioral outc ome following lateral FP brain injury. For more significant behavioral and/ or morphological change to occur, we would suggest that the duration of chr onic ethanol administration must be increased.