Bayerl Simon H, Nieminen-Kelhä Melina, Broggini Thomas, Vajkoczy Peter, Prinz Vincent
Department of Neurosurgery and Center for Stroke-research Berlin (CSB), Charité-Universitätsmedizin.
Department of Physics, University of California San Diego.
J Vis Exp. 2016 Dec 29(118):54701. doi: 10.3791/54701.
Focal cerebral ischemia (i.e., ischemic stroke) may cause major brain injury, leading to a severe loss of neuronal function and consequently to a host of motor and cognitive disabilities. Its high prevalence poses a serious health burden, as stroke is among the principal causes of long-term disability and death worldwide. Recovery of neuronal function is, in most cases, only partial. So far, treatment options are very limited, in particular due to the narrow time window for thrombolysis. Determining methods to accelerate recovery from stroke remains a prime medical goal; however, this has been hampered by insufficient mechanistic insights into the recovery process. Experimental stroke researchers frequently employ rodent models of focal cerebral ischemia. Beyond the acute phase, stroke research is increasingly focused on the sub-acute and chronic phase following cerebral ischemia. Most stroke researchers apply permanent or transient occlusion of the MCA in mice or rats. In patients, occlusions of the MCA are among the most frequent causes of ischemic stroke. Besides proximal occlusion of the MCA using the filament model, surgical occlusion of the distal MCA is probably the most frequently used model in experimental stroke research. Occlusion of a distal (to the branching of the lenticulo-striate arteries) MCA branch typically spares the striatum and primarily affects the neocortex. Vessel occlusion can be permanent or transient. High reproducibility of lesion volume and very low mortality rates with respect to the long-term outcome are the main advantages of this model. Here, we demonstrate how to perform a chronic cranial window (CW) preparation lateral to the sagittal sinus, and afterwards how to surgically induce a distal stroke underneath the window using a craniotomy approach. This approach can be applied for sequential imaging of acute and chronic changes following ischemia via epi-illuminating, confocal laser scanning, and two-photon intravital microscopy.
局灶性脑缺血（即缺血性中风）可能导致严重的脑损伤，导致神经元功能严重丧失，进而引发一系列运动和认知障碍。其高发病率构成了严重的健康负担，因为中风是全球长期残疾和死亡的主要原因之一。在大多数情况下，神经元功能的恢复只是部分性的。到目前为止，治疗选择非常有限，特别是由于溶栓的时间窗很窄。确定加速中风恢复的方法仍然是首要的医学目标；然而，这一目标因对恢复过程的机制认识不足而受到阻碍。实验性中风研究人员经常使用局灶性脑缺血的啮齿动物模型。除急性期外，中风研究越来越关注脑缺血后的亚急性期和慢性期。大多数中风研究人员在小鼠或大鼠中应用大脑中动脉（MCA）的永久性或短暂性闭塞。在患者中，MCA闭塞是缺血性中风最常见的原因之一。除了使用线栓模型进行MCA近端闭塞外，远端MCA的手术闭塞可能是实验性中风研究中最常用的模型。闭塞远端（至豆纹动脉分支处）的MCA分支通常可使纹状体幸免，主要影响新皮质。血管闭塞可以是永久性的或短暂性的。该模型的主要优点是病变体积的高重复性和相对于长期结果的极低死亡率。在这里，我们展示了如何在矢状窦外侧进行慢性颅骨开窗（CW）制备，然后如何使用开颅手术方法在窗口下方手术诱导远端中风。这种方法可用于通过落射照明、共聚焦激光扫描和双光子活体显微镜对缺血后急性和慢性变化进行连续成像。
