Developing the therapeutic methods for mitochondrial function, which may related to the neuronal recovery in penumbral region

为了阐明半暗区反复去极化的传播，我们观察了局灶性缺血大鼠皮质NADH的荧光。缺血是通过收紧左中央动脉结扎，并用连接微机械臂的80 μm不锈钢钩将血管提升到皮质表面以上1mm处，从而阻塞中央动脉。在左侧顶骨-颞骨上做了一个大颅窗，观察几乎整个左侧皮质半球。用366nm紫外灯照射皮质表面，用带460nm带通滤光片的CCD相机每17秒拍摄一张NADH荧光图像。在3小时的缺血期间，在45只动物中观察到220次周期性去极化，其高信号强度波起源于缺血核心的边缘，并沿着缺血核心的圆形边缘移动。反复去极化分为两种类型：“扩散型”（86%），即反复去极化向外扩散，不增加缺血核的面积；“扩张型”（14%），即反复去极化与缺血核合并，增加缺血核的面积。组织学检查显示，半暗区发生神经元损伤，可见“铺展型”复发性去极化，缺血核心发生梗死，可见“扩张型”复发性去极化。

To elucidate the propagation of recurrent depolarization in the penumbra, the fluorescence of cortical NADH was observed in rats that had been subjected to focal ischemia. Ischemia was initiated by tightening the left CCA ligature and occluding the MCA by lifting the vessel 1 mm above the cortical surface with an 80-μm stainless-steel hook attached to a micromanipulator. A large cranial window was made on the left parietal-temporal bone to observe almost the entire left cortical hemisphere. The cortical surface was illuminated using a UV lamp (366nm), and images of NADH fluorescence were taken every 17 seconds using a CCD camera with a 460nm bandpass filter. During a three-hour period of ischemia, 220 recurrent depolarizations were observed in 45 animals as waves of high signal intensity that originated at the edge of the ischemic core and moved along the round margin of the ischemic core. Recurrent depolarizations were classified into two types : "spread-out type (86%)" in which recurrent depolarization spread out and did not increase the area of the ischemic core, and "expansion type (14%)" in which recurrent depolarization merged with the ischemic core and increased the area of the ischemic core. Histological examination revealed that neuronal injury occurred in the penumbral region, in which "spread-out type" of recurrent depolarization was observed, and that infarction occurred in the ischemic core, in which "expansion type" of recurrent depolarization was observed.