title: The exercise-induced expression of BDNF within the hippocampus varies across life-span.
abstract: Voluntary exercise increases hippocampal brain-derived neurotrophic factor (BDNF) expression in young animals. In this investigation we examined the induction of BDNF protein in the hippocampus of young (2 months), late middle-aged (15 months) and old (24 months) animals over 4 weeks of exercise. Average running distances decreased with age, with the old animals also maintaining a constant level of activity over time, whereas the other groups tended to increase their average running distance. All animals demonstrated a biphasic profile of BDNF protein induction, with a significant (P<0.05) increase after 1 week of exercise followed by a decrease to near sedentary levels at 2 weeks. After this, BDNF protein levels increased significantly (P<0.05), as compared to baseline, primarily only in the young animals. In whole hippocampal homogenates, only particular BDNF mRNA exons were significantly (P<0.05) changed as a result of exercise, with the largest induction occurring in young animals. BDNF protein induction may, therefore, not be directly correlated with significant mRNA changes. Exercise may represent a therapeutic tool for disorders which involve a decrease in BDNF.
authors.affiliation: Institute for Brain Aging and Dementia, University of California, 1125 Gillespie N.R.F, Irvine, CA 92697-4540, USA. padlard@uci.edu
authors.forename: Paul A
authors.initials: PA
authors.lastname: Adlard
authors.forename: Victoria M
authors.initials: VM
authors.lastname: Perreau
authors.forename: Carl W
authors.initials: CW
authors.lastname: Cotman
mesh_terms: D000367:Age Factors; D000375:Aging / Q000502:physiology*; D000818:Animals; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005091:Exons; D005786:Gene Expression Regulation / Q000502:physiology*; D006624:Hippocampus / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D010805:Physical Conditioning, Animal / Q000502:physiology*; D012333:RNA, Messenger / Q000096:biosynthesis; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D013997:Time Factors
chemical_list: D019208:Brain-Derived Neurotrophic Factor; D012333:RNA, Messenger