光学成像观测大鼠局灶性脑缺血的动态过程

Dynamic Evolution of Focal Cerebral Ischemia in Rats Observed by Optical Imaging

采用550nm内源信号光学成像(opticalintrinsicsignalimaging,OISI)监测左侧大脑中动脉栓塞(middlecerebralarteryocclusion,MCAO)局灶性脑缺血大鼠顶叶皮层.MCAO后4h内,观测到一系列自发扩散性抑制(spreadingdepression,SD)波(10.3±4.6)次.前2h内的SD波通常会侵袭整个左侧顶叶皮层,但光信号有明显的区域差异.后2h内的SD波局限于顶叶皮层中央区域,且传播面积逐次减少;旁侧区域光强基线逐步升高,4h时,反射光强升高(8.4±1.2)%.随后TTC染色证明上述旁侧区域已经梗死.实验表明光学成像为确定缺血半暗带并监测其动态发展提供了一种有效方法.

The optical intrinsic signal imaging （OISI） at 550nm was applied to examine the parietal cortex of focal cerebral ischemia rats with the left middle cerebral artery occlusion （MCAO）. A series of spontaneous spreading depression （SD） waves （10.3±4.6 times） were observed during the next 4 h after MCAO. In the earlier 2 h, the SD waves usually spread across the whole left parietal cortex, however, the optical signals showed significant regional differences. During the later 2 h, the waves were restricted in the medial parietal cortex, and the propagated area decreased reversely with the increasing times of SD waves. The baseline intensity in the lateral area increased steadily, up to （8.4±1.2） % at the end of 4 h. By TTC staining, the lateral area proved to infract focus. The results suggested that the optical imaging supplied an effective method to identify the ischemic penumbra and monitor its dynamic evolution.