title: Diffuse optical monitoring of repeated cerebral ischemia in mice.
abstract: Occlusions of bilateral common carotid arteries (bi-CCA) in mice are popular models for the investigation of transient forebrain ischemia. Currently available technologies for assessing cerebral blood flow (CBF) and oxygenation in ischemic mice have limitations. This study tests a novel near-infrared diffuse correlation spectroscopy (DCS) flow-oximeter for monitoring both CBF and cerebral oxygenation in mice undergoing repeated transient forebrain ischemia. Concurrent flow measurements in a mouse brain were first conducted for validation purposes; DCS measurement was found highly correlated with laser Doppler measurement (R2 = 0.94) and less susceptible to motion artifacts. With unique designs in experimental protocols and fiber-optic probes, we have demonstrated high sensitivities of DCS flow-oximeter in detecting the regional heterogeneity of CBF responses in different hemispheres and global changes of both CBF and cerebral oxygenation across two hemispheres in mice undergoing repeated 2-minute bi-CCA occlusions over 5 days. More than 75% CBF reductions were found during bi-CCA occlusions in mice, which may be considered as a threshold to determine a successful bi-CCA occlusion. With the progress of repeated 2-minute bi-CCA occlusions over days, a longitudinal decline in the magnitudes of CBF reduction was observed, indicating the brain adaptation to cerebral ischemia through the repeated preconditioning.
authors: Center for Biomedical Engineering, University of Kentucky, Lexington, Kentucky 40506, USA.
authors: Yu
authors: Y
authors: Shang
authors: Lei
authors: L
authors: Chen
authors: Michal
authors: M
authors: Toborek
authors: Guoqiang
authors: G
authors: Yu
mesh_terms: D000818:Animals; D001709:Biotechnology / Q000379:methods; D002545:Brain Ischemia / Q000473:pathology*; D004867:Equipment Design; D008027:Light; D008297:Male; D008422:Materials Testing; D051379:Mice; D008810:Mice, Inbred C57BL; D055095:Optics and Photonics / Q000379:methods*; D010092:Oximetry / Q000379:methods; D013053:Spectrophotometry / Q000379:methods; D013997:Time Factors