title: Functional laser speckle imaging of cerebral blood flow under hypothermia.
abstract: Hypothermia can unintentionally occur in daily life, e.g., in cardiovascular surgery or applied as therapeutics in the neurosciences critical care unit. So far, the temperature-induced spatiotemporal responses of the neural function have not been fully understood. In this study, we investigated the functional change in cerebral blood flow (CBF), accompanied with neuronal activation, by laser speckle imaging (LSI) during hypothermia. Laser speckle images from Sprague-Dawley rats (n = 8, male) were acquired under normothermia (37°C) and moderate hypothermia (32°C). For each animal, 10 trials of electrical hindpaw stimulation were delivered under both temperatures. Using registered laser speckle contrast analysis and temporal clustering analysis (TCA), we found a delayed response peak and a prolonged response window under hypothermia. Hypothermia also decreased the activation area and the amplitude of the peak CBF. The combination of LSI and TCA is a high-resolution functional imaging method to investigate the spatiotemporal neurovascular coupling in both normal and pathological brain functions.
authors: Shanghai Jiao Tong University, School of Biomedical Engineering, Shanghai 200240, China.
authors: Minheng
authors: M
authors: Li
authors: Peng
authors: P
authors: Miao
authors: Yisheng
authors: Y
authors: Zhu
authors: Shanbao
authors: S
authors: Tong
mesh_terms: D000818:Animals; D001831:Body Temperature / Q000502:physiology; D001921:Brain / Q000098:blood supply*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D016000:Cluster Analysis; D003952:Diagnostic Imaging / Q000379:methods*; D018056:Hemorheology / Q000502:physiology; D006614:Hindlimb; D007036:Hypothermia, Induced; D007834:Lasers; D016014:Linear Models; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley