ABSTRACT
Objective To investigate the effects of chronic ethanol exposure and withdrawal on the expression of actin-binding protein cofilin,p-cofilin and cyclin-dependent kinase-5 (cdk5) in the nucleus accumbens and striatum in rat brain.Methods Twenty-four male SD rats were randomly divided into one control group and three experimental groups.In the experimental groups,ethanol was administered in drinking water at the concentration of 6％ (V/V) for two months.Rats in control group drank normal drinking water.After two months ethanol was removed and ethanol withdrawal syndromes were evaluated.Rats were sacrificed on withdrawal 0 h,withdrawal 6 h and withdrawal 2 d.The expression levels of cofilin,p-cofilin(ser3)and cdk5 in the rat brain were measured by immunohistochemistry methods.Results Withdrawal syndrome scores of ethanol fed rats were obviously higher than those of control rats after ethanol was removed,the highest score occurred at 6 h after ethanol withdrawal.In the nucleus accumbens area of rat brain,the levels of cofilin on withdrawal 0 h significantly decreased compared with control group ((0.31±0.05),(0.39± 0.05),P＜ 0.05).The levels of cdk5 on withdrawal 0 h and withdrawal 6 h significantly increased compared with control group((0.36±0.07),(0.34±0.07),(0.25±0.05),P＜0.05).In the striatum of rat brain,the levels of cofilin on withdrawal 0 h significantly decreased compared with control group ((0.26±0.04),(0.34±0.05),P＜0.05).The levels of p-cofilin on withdrawal 6 h significantly increased compared with control group((0.43±0.06),(0.30±0.06),P＜0.01).The levels of cdk5 on withdrawal 0 h significantly increased compared with control group((0.35±0.06),(0.26±0.05),P＜0.05),and the levels of cofilin on withdrawal 6 h significantly decreased compared with control group((0.37±0.06),(0.26±0.05),P＜0.01).Conclusion Chronic ethanol exposure can induce the development of ethanol dependence,and it accompanies with changes in the expression of actin-binding protein and cdk5 in the brain of rats.