The exercise-induced expression of BDNF within the hippocampus varies across life-span

Neurobiol Aging. 2005 Apr;26(4):511-20. doi: 10.1016/j.neurobiolaging.2004.05.006.


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.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Age Factors
  • Aging / physiology*
  • Animals
  • Brain-Derived Neurotrophic Factor / genetics
  • Brain-Derived Neurotrophic Factor / metabolism*
  • Enzyme-Linked Immunosorbent Assay / methods
  • Exons
  • Gene Expression Regulation / physiology*
  • Hippocampus / metabolism*
  • Mice
  • Mice, Inbred C57BL
  • Physical Conditioning, Animal / physiology*
  • RNA, Messenger / biosynthesis
  • Reverse Transcriptase Polymerase Chain Reaction / methods
  • Time Factors


  • Brain-Derived Neurotrophic Factor
  • RNA, Messenger