Effects of chronic ethanol administration on expression of BDNF and trkB mRNAs in rat hippocampus after experimental brain injury

Previous evidence indicates that both chronic alcohol treatment and traumat ic brain injury modulate expression of certain neurotrophins and neurotroph in receptors in cortical tissue. However, the combined effects of chronic a lcohol and brain trauma on expression of neurotrophins and their receptors have not been investigated. In the present study, we examined the effects o f 6 weeks of chronic ethanol administration on lateral fluid percussion (FP ) brain injury-induced alterations in expression of mRNAs for the neurotrop hin brain-derived neurotrophic factor (BDNF) and its high affinity receptor , trkB, in rat hippocampus. In both the control- (pair-fed isocaloric sucro se) diet and the chronic ethanol-diet groups, unilateral FP brain injury in duced a bilateral increase in levels of both BDNF and trkB mRNAs in the den tate gyrus granule cell layer, and of BDNF mRNA in hippocampal region CA3. However, no significant differences in expression were found between the co ntrol-diet and ethanol-diet groups, in either the sham-injured or FP-injure d animals. These findings suggest that 6 weeks of chronic ethanol administr ation does not alter the plasticity of hippocampal BDNF/trkB expression in response to experimental brain injury. (C) 2000 Elsevier Science B.V. All r ights reserved.