Diffusion tensor-MRI detects exercise-induced neuroplasticity in the hippocampal microstructure in mice

Mohammad R Islam; Renhao Luo; Sophia Valaris; Erin B Haley; Hajime Takase; Yinching Iris Chen; Bradford C Dickerson; Karin Schon; Ken Arai; Christopher T Nguyen; Christiane D Wrann

doi:10.3233/BPL-190090

Diffusion tensor-MRI detects exercise-induced neuroplasticity in the hippocampal microstructure in mice

Brain Plast. 2020 Oct 1;5(2):147-159. doi: 10.3233/BPL-190090.

Authors

Mohammad R Islam¹, Renhao Luo¹, Sophia Valaris¹, Erin B Haley¹, Hajime Takase², Yinching Iris Chen³, Bradford C Dickerson^{3

4}, Karin Schon⁵, Ken Arai², Christopher T Nguyen^{1

3}, Christiane D Wrann^{1

6

7}

Affiliations

¹ Cardiovascular Research Center, Massachusetts General Hospital Research Institute and Harvard Medical School, Boston, MA, USA.
² Neuroprotection Research Laboratory, Departments of Radiology and Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA.
³ Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA.
⁴ Department of Neurology, Massachusetts General Hospital, Boston, MA, USA.
⁵ Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, MA, USA.
⁶ Harvard Stem Cell Institute, Harvard University, Cambridge, MA, USA.
⁷ Henry and Allison McCance Center for Brain Health, Massachusetts General Hospital, Boston, MA, USA.

Abstract

Background: Despite considerable research on exercise-induced neuroplasticity in the brain, a major ongoing challenge in translating findings from animal studies to humans is that clinical and preclinical settings employ very different techniques.

Objective: Here we aim to bridge this divide by using diffusion tensor imaging MRI (DTI), an advanced imaging technique commonly applied in human studies, in a longitudinal exercise study with mice.

Methods: Wild-type mice were exercised using voluntary free-wheel running, and MRI scans were at baseline and after four weeks and nine weeks of running.

Results: Both hippocampal volume and fractional anisotropy, a surrogate for microstructural directionality, significantly increased with exercise. In addition, exercise levels correlated with effect size. Histological analysis showed more PDGFRα+ oligodendrocyte precursor cells in the corpus callosum of running mice.

Conclusions: These results provide compelling in vivo support for the concept that similar adaptive changes occur in the brains of mice and humans in response to exercise.

Keywords: DTI; MRI; exercise; hippocampus; neuroplasticity.

Grants and funding

R01 HL151704/HL/NHLBI NIH HHS/United States