Hemodynamic changes during neural deactivation in awake mice: a measurement by laser-Doppler flowmetry in crossed cerebellar diaschisis.
Crossed cerebellar diaschisis (CCD) caused by contralateral supratentorial lesions can be considered a condition of neural deactivation, and hemodynamic changes in CCD were investigated with positron emission tomography (PET) in humans. In the present study, to investigate the effects of neural deactivation on hemodynamics, we developed a new mouse model of CCD, which was caused by middle cerebral artery occlusion (MCAO), and measured changes in cerebellar blood flow (CbBF), red blood cell (RBC) velocity and concentration due to CCD using laser-Doppler flowmetry (LDF) in awake mice. The ratio of the CCD side to the unaffected side in the cerebellum for CbBF 1 day after MCAO was decreased by -18% compared to baseline (before CCD). The ratio of the CCD side to the unaffected side for RBC concentration 1 day after MCAO was decreased by -23% compared to baseline. However, no significant changes in the ratio of the CCD side to the unaffected side were observed for RBC velocity. The present results indicate that the reduction of CbBF induced by neural deactivation was mainly caused by the decrease in RBC concentration. In contrast, our previous study showed that RBC velocity had a dominant role in the increase in cerebral blood flow (CBF) induced by neural activation. If RBC concentration can be considered an indicator of cerebral blood volume (CBV), hemodynamic changes due to neural activation and deactivation measured by LDF in mice might be in good agreement with human PET studies.
Department of Biophysics Program, Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan.
Hiroyuki
H
Takuwa
Yosuke
Y
Tajima
Daisuke
D
Kokuryo
Tetsuya
T
Matsuura
Hiroshi
H
Kawaguchi
Kazuto
K
Masamoto
Junko
J
Taniguchi
Yoko
Y
Ikoma
Chie
C
Seki
Ichio
I
Aoki
Yutaka
Y
Tomita
Norihiro
N
Suzuki
Iwao
I
Kanno
Hiroshi
H
Ito
D000818:Animals; D001783:Blood Flow Velocity / Q000187:drug effects; D002531:Cerebellum / Q000098:blood supply* / Q000473:pathology; D002544:Cerebral Infarction / Q000503:physiopathology; D002560:Cerebrovascular Circulation / Q000502:physiology*; D006439:Hemodynamics / Q000502:physiology*; D017078:Laser-Doppler Flowmetry / Q000379:methods; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D049268:Positron-Emission Tomography / Q000379:methods; D014055:Tomography, Emission-Computed / Q000379:methods; D014851:Wakefulness
Awake animal; Cerebellar blood flow; Crossed cerebellar diaschisis; Neuronal deactivation; Red blood cell concentration; Red blood cell velocity