Physical exercise induces structural alterations in the hippocampal astrocytes: exploring the role of BDNF-TrkB signaling

  • Atoossa Fahimi
  • Mehmet Akif Baktir
  • Sarah Moghadam
  • Fatemeh S. Mojabi
  • Krithika Sumanth
  • M. Windy McNerney
  • Ravikumar Ponnusamy
  • Ahmad Salehi
Original Article

DOI: 10.1007/s00429-016-1308-8

Cite this article as:
Fahimi, A., Baktir, M.A., Moghadam, S. et al. Brain Struct Funct (2016). doi:10.1007/s00429-016-1308-8

Abstract

While it has been known that physical activity can improve cognitive function and protect against neurodegeneration, the underlying mechanisms for these protective effects are yet to be fully elucidated. There is a large body of evidence indicating that physical exercise improves neurogenesis and maintenance of neurons. Yet, its possible effects on glial cells remain poorly understood. Here, we tested whether physical exercise in mice alters the expression of trophic factor-related genes and the status of astrocytes in the dentate gyrus of the hippocampus. In addition to a significant increase in Bdnf mRNA and protein levels, we found that 4 weeks of treadmill and running wheel exercise in mice, led to (1) a significant increase in synaptic load in the dentate gyrus, (2) alterations in astrocytic morphology, and (3) orientation of astrocytic projections towards dentate granule cells. Importantly, these changes were possibly linked to increased TrkB receptor levels in astrocytes. Our study suggests that astrocytes actively respond and could indeed mediate the positive effects of physical exercise on the central nervous system and potentially counter degenerative processes during aging and neurodegenerative disorders.

Keywords

Physical activityHippocampusDentate gyrusBdnfGFAPAstrocytes

Supplementary material

429_2016_1308_MOESM1_ESM.eps (1.6 mb)
Fig. S1A-B a) Schematic representation of the treadmill used in this study. The device had six separate lanes separated by opaque walls for simultaneous physical exercise with minimal stress. b) The timeline of physical exercise in this experiment: following a week of habituation, each exercise mouse received 5 days of treadmill exercise (5 days per week for 4 weeks). TM = treadmill, RW = Running wheel. Treadmill exercise was consisted of two 20-minute running time followed by a 10-minute rest on the belts (EPS 1627 kb)
429_2016_1308_MOESM2_ESM.docx (118 kb)
Supplementary material 2 (Table S1) (DOCX 118 kb)

Copyright information

© Springer-Verlag Berlin Heidelberg (outside the USA) 2016

Authors and Affiliations

  1. 1.VA Palo Alto Health Care SystemPalo AltoUSA
  2. 2.Department of Psychiatry and Behavioral SciencesStanford University School of MedicinePalo AltoUSA