Physical exercise induces structural alterations in the hippocampal astrocytes: exploring the role of BDNF-TrkB signaling.
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.
VA Palo Alto Health Care System, 3801 Miranda Ave, Palo Alto, CA, 94304, USA.|Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Palo Alto, CA, 94304, USA.
Atoossa
A
Fahimi
VA Palo Alto Health Care System, 3801 Miranda Ave, Palo Alto, CA, 94304, USA.
Mehmet Akif
MA
Baktir
VA Palo Alto Health Care System, 3801 Miranda Ave, Palo Alto, CA, 94304, USA.
Sarah
S
Moghadam
VA Palo Alto Health Care System, 3801 Miranda Ave, Palo Alto, CA, 94304, USA.|Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Palo Alto, CA, 94304, USA.
Fatemeh S
FS
Mojabi
VA Palo Alto Health Care System, 3801 Miranda Ave, Palo Alto, CA, 94304, USA.
Krithika
K
Sumanth
VA Palo Alto Health Care System, 3801 Miranda Ave, Palo Alto, CA, 94304, USA.|Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Palo Alto, CA, 94304, USA.
M Windy
MW
McNerney
VA Palo Alto Health Care System, 3801 Miranda Ave, Palo Alto, CA, 94304, USA.
Ravikumar
R
Ponnusamy
VA Palo Alto Health Care System, 3801 Miranda Ave, Palo Alto, CA, 94304, USA. asalehi@stanford.edu.|Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Palo Alto, CA, 94304, USA. asalehi@stanford.edu.
Ahmad
http://orcid.org/0000-0001-8257-3280
A
Salehi
D000818:Animals; D001253:Astrocytes / Q000166:cytology* / Q000378:metabolism*; D019208:Brain-Derived Neurotrophic Factor / Q000378:metabolism*; D006624:Hippocampus / Q000166:cytology* / Q000378:metabolism*; D008297:Male; D008810:Mice, Inbred C57BL; D009043:Motor Activity; D009473:Neuronal Plasticity; D020813:Receptor, trkB / Q000378:metabolism*
D019208:Brain-Derived Neurotrophic Factor; D020813:Receptor, trkB
Astrocytes; Bdnf; Dentate gyrus; GFAP; Hippocampus; Physical activity