title: Impact of a single bout of aerobic exercise on regional brain perfusion and activation responses in healthy young adults.
abstract: OBJECTIVE
  Despite the generally accepted view that aerobic exercise can have positive effects on brain health, few studies have measured brain responses to exercise over a short time span. The purpose of this study was to examine the impact within one hour of a single bout of exercise on brain perfusion and neuronal activation.
  
  
  METHODS
  Healthy adults (n = 16; age range: 20-35 yrs) were scanned using Magnetic Resonance Imaging (MRI) before and after 20 minutes of exercise at 70% of their age-predicted maximal heart rate. Pseudo-continuous arterial spin labeling (pcASL) was used to measure absolute cerebral blood flow (CBF) prior to exercise (pre) and at 10 min (post-10) and 40 min (post-40) post-exercise. Blood oxygenation level dependent (BOLD) functional MRI (fMRI) was performed pre and post-exercise to characterize activation differences related to a go/no-go reaction time task.
  
  
  RESULTS
  Compared to pre-exercise levels, grey matter CBF was 11% (±9%) lower at post-10 (P<0.0004) and not different at post-40 (P = 0.12), while global WM CBF was increased at both time points post-exercise (P<0.0006). Regionally, the hippocampus and insula showed a decrease in perfusion in ROI-analysis at post-10 (P<0.005, FDR corrected), whereas voxel-wise analysis identified elevated perfusion in the left medial postcentral gyrus at post-40 compared to pre (pcorrected = 0.05). BOLD activations were consistent between sessions, however, the left parietal operculum showed reduced BOLD activation after exercise.
  
  
  CONCLUSIONS
  This study provides preliminary evidence of regionalized brain effects associated with a single bout of aerobic exercise. The observed acute cerebrovascular responses may provide some insight into the brain's ability to change in relation to chronic interventions.
authors.affiliation: Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada ; Canadian Partnership for Stroke Recovery, Sunnybrook Research Institute, Toronto, Ontario, Canada.
authors.forename: Bradley J
authors.initials: BJ
authors.lastname: MacIntosh
authors.affiliation: Canadian Partnership for Stroke Recovery, Sunnybrook Research Institute, Toronto, Ontario, Canada.
authors.forename: David E
authors.initials: DE
authors.lastname: Crane
authors.affiliation: Toronto Rehabilitation Institute, University of Toronto, Toronto, Ontario, Canada ; Graduate Department of Rehabilitation Science, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Michael D
authors.initials: MD
authors.lastname: Sage
authors.affiliation: Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada ; Canadian Partnership for Stroke Recovery, Sunnybrook Research Institute, Toronto, Ontario, Canada.
authors.forename: A Saeed
authors.initials: AS
authors.lastname: Rajab
authors.affiliation: Department of Radiology, Vanderbilt University, Nashville, Tennessee, United States of America.
authors.forename: Manus J
authors.initials: MJ
authors.lastname: Donahue
authors.affiliation: Canadian Partnership for Stroke Recovery, Sunnybrook Research Institute, Toronto, Ontario, Canada ; Toronto Rehabilitation Institute, University of Toronto, Toronto, Ontario, Canada ; Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada.
authors.forename: William E
authors.initials: WE
authors.lastname: McIlroy
authors.affiliation: Canadian Partnership for Stroke Recovery, Sunnybrook Research Institute, Toronto, Ontario, Canada ; Toronto Rehabilitation Institute, University of Toronto, Toronto, Ontario, Canada ; Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada.
authors.forename: Laura E
authors.initials: LE
authors.lastname: Middleton
mesh_terms: D000328:Adult; D001783:Blood Flow Velocity; D001931:Brain Mapping; D002560:Cerebrovascular Circulation / Q000502:physiology*; D018891:Dentate Gyrus / Q000098:blood supply / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D010100:Oxygen / Q000502:physiology*; D010296:Parietal Lobe / Q000098:blood supply / Q000502:physiology*; D011930:Reaction Time; D013113:Spin Labels
chemical_list: D013113:Spin Labels; D010100:Oxygen