采用线栓法制备大鼠大脑中动脉栓塞(middle cerebral artery occlusion,MCAO)模型,在额叶皮层用KCl诱导产生皮层扩散性抑制(cortical spreadingdepression,CSD).MCA04 h后,利用550 nm内源信号光学成像(optical intrinsic signalimaging,OISI)监测局灶性脑缺血后大鼠顶-枕叶皮层内源光信号变化.成像1 h内观测到一系列诱导CSD波(14±3次),CSD波局限于顶-枕叶皮层中央区域扩展,以光强的显著下降为特征;而旁侧区域光强无明显改变,不具备CSD波特征,表明CSD波未传播到该区域.随后TIC染色证明上述旁侧区域已经梗死.实验表明:MCAO后4h,皮层区域旁侧部分会梗死;CSD波的0IS变化可用来区分缺血梗死区和外周供血较为完整区域(未梗死区).

Focal cerebral ischemia in rats was induced by middle cerebral artery occlusion(MCAO)with monofilament, and cortical spreading depression (CSD) was elicited by applying KCl to frontal cortex 4 h after MCAO. The optical intrinsic signal imaging (OISI) at 550 nm was applied to examine the change of optical intrinsic signals in parietal-occipital cortex after focal cerebral ischemia. A series of induced CSD waves were observed for 1 h during imaging (14±3 times). The CSD waves were restricted in the medial parietal-occipital cortex, and were characterized with the obvious decrease of OIS. However, the OIS in lateral area did not change and had no SD properties. It showed the CSD waves didn't spread to lateral area. By TTC staining, such area was proved the infract focus. The results suggested lateral area would be the infract focus 4 h after MCAO and the change of OIS of CSD waves can be used to confirm the infarcted area and the surrounding intact cortex (uninfarct area).