Evidence of functional hyperemia in the rat hippocampus during mild treadmill running.
Exercise appears to improve hippocampal plasticity and cognitive function, leading us to postulate that exercise may activate hippocampal neurons, which in turn increase hippocampal cerebral blood flow (Hip-CBF). Recent studies using laser-Doppler flowmetry (LDF) have shown that Hip-CBF increases with behavior and locomotion, but it has not been examined whether these changes are due to neuronal activation. We aimed to examine whether functional hyperemia, an increase in cerebral blood flow in response to neuronal activation, can occur in the exercising rat hippocampus. We applied a treadmill running model of rats and LDF combined with microdialysis. Prolonged mild treadmill running (10 m/min) resulted in an increase in Hip-CBF of 26+/-9% versus basal level. When tetrodotoxin was infused via microdialysis into the loci where Hip-CBF was monitored, the increased Hip-CBF with running was completely suppressed. These results provide evidence that functional hyperemia occurs in the rat hippocampus during mild treadmill running and suggest that our running animal model may be useful for examining the underlying mechanisms of exercise-induced hippocampal functional hyperemia.
Nishijima
Takeshi
T
Laboratory of Exercise Biochemistry, University of Tsukuba Graduate School of Comprehensive Human Sciences, Tsukuba 305-8574, Ibaraki, Japan.
Soya
Hideaki
H
D000818:Animals; D002560:Cerebrovascular Circulation / Q000187:drug effects / Q000502:physiology; D006624:Hippocampus / Q000098:blood supply*; D006940:Hyperemia / Q000209:etiology*; D007276:Injections, Intraventricular; D017078:Laser-Doppler Flowmetry; D008297:Male; D017551:Microdialysis; D010805:Physical Conditioning, Animal / Q000502:physiology*; D011042:Poisons / Q000008:administration & dosage; D051381:Rats; D017208:Rats, Wistar; D013779:Tetrodotoxin / Q000008:administration & dosage
D011042:Poisons; D013779:Tetrodotoxin