Physical activity increases mRNA for brain-derived neurotrophic factor and nerve growth factor in rat brain

Brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) support the viability and function of many types of neurons, and are likely mediators of activity-dependent changes in the CNS. We examined BDNF and NGF mRNA levels in several brain areas of adult male rats following 0, 2, 4, or 7 nights with ad libitum access to running wheels. BDNF mRNA was significantly increased in several brain areas, most notably in the hippocampus and caudal13 of cerebral cortex following 2, 4, and 7 nights with exercise. Significant elevations in BDNF mRNA were localized in Ammon's horn areas 1 (CAI) and 4 (CA4) of the hippocampus, and layers II–III of the caudal neocortex and retrosplenial cortex. NGF mRNA was also significantly elevated in the hippocampus and caudal13 of the cortex, affecting primarily the dentate gyrus granular layer (DG) and CA4 of the hippocampus and layers II–III in caudal neocortex.