Correlation between hippocampal BDNF mRNA expression and memory performance in senescent rats

Brain-derived neurotrophic factor (BDNF) has been suggested to be involved in memory processes. In the present study, the association between memory i mpairment at senescence and BDNF expression in the hippocampus was studied in 30-32-month-old Brown Norway rats, which had been maternally deprived ea rly in life. These animals display a bimodal distribution in their spatial learning ability: rats are either non-impaired or impaired. BDNF mRNA expre ssion in the hippocampus was compared between non-impaired and impaired rat s. We measured BDNF mRNA expression in the hippocampus 3 h after training i n the Morris water maze ('post-training') and at I month after training ('b asal'). Non-impaired performers displayed a higher post-training BDNF mRNA level in the CAI region than impaired rats. In addition, only in the non-im paired performers post-training BDNF mRNA levels in CAI and dentate gyrus w ere increased as compared to basal levels. Thus, we have demonstrated that in senescent rats, hippocampal BDNF expression in response to water maze tr aining is associated with memory performance. (C) 2001 Elsevier Science BY All rights reserved.