Repetitive Cerebral Blood Flow Measurements Using Laser Speckle Imaging in a Transient Cerebral Ischemic Mouse Model

Abstract

Using laser speckle imaging (LSI), which can visualize quadratic distribution of blood flow, we measured blood flow changes in transient cerebral ischemic mice, and compared these results with data obtained using laser Doppler flowmetry (LDF). In addition, we examined the relationship between ischemic damage and blood flow change. ICR mice (n = 22) were subjected to transient middle cerebral artery occlusion using a 6-0 monofilament under general anesthesia. LSI was performed before ­ischemia, during ischemia, and 30 min, 3 h, 24 h, 7 days, and 28 days after ischemia. LDF was monitored continuously from pre-ischemia to 10 min after ischemia commenced. The level of cerebral blood flow (CBF) measured by LSI was less than that using LDF. LSI was able to measure CBF quantitatively and repeatedly. Blood flow ­measurements using LSI revealed that recovery of cerebral cortical blood flow after ischemia in mice without cortical infarction was earlier than that seen in mice with cortical infarction. This study indicates that LSI is a ­useful technique for analyzing the relationship between ­tissue damage and cerebral blood flow change following cerebral ischemia.