Xavier Anna L R, Hauglund Natalie Linea, von Holstein-Rathlou Stephanie, Li Qianliang, Sanggaard Simon, Lou Nanhong, Lundgaard Iben, Nedergaard Maiken
Center for Translational Neuromedicine, Division of Glial Therapeutics, University of Copenhagen;
Center for Translational Neuromedicine, Division of Glial Therapeutics, University of Copenhagen.
J Vis Exp. 2018 May 23(135):57378. doi: 10.3791/57378.
Cisterna magna cannulation (CMc) is a straightforward procedure that enables direct access to the cerebrospinal fluid (CSF) without operative damage to the skull or the brain parenchyma. In anesthetized rodents, the exposure of the dura mater by blunt dissection of the neck muscles allows the insertion of a cannula into the cisterna magna (CM). The cannula, composed either by a fine beveled needle or borosilicate capillary, is attached via a polyethylene (PE) tube to a syringe. Using a syringe pump, molecules can then be injected at controlled rates directly into the CM, which is continuous with the subarachnoid space. From the subarachnoid space, we can trace CSF fluxes by convective flow into the perivascular space around penetrating arterioles, where solute exchange with the interstitial fluid (ISF) occurs. CMc can be performed for acute injections immediately following the surgery, or for chronic implantation, with later injection in anesthetized or awake, freely moving rodents. Quantitation of tracer distribution in the brain parenchyma can be performed by epifluorescence, 2-photon microscopy, and magnetic resonance imaging (MRI), depending on the physico-chemical properties of the injected molecules. Thus, CMc in conjunction with various imaging techniques offers a powerful tool for assessment of the glymphatic system and CSF dynamics and function. Furthermore, CMc can be utilized as a conduit for fast, brain-wide delivery of signaling molecules and metabolic substrates that could not otherwise cross the blood brain barrier (BBB).
枕大池置管（CMc）是一种简单的操作，可直接获取脑脊液（CSF），而不会对颅骨或脑实质造成手术损伤。在麻醉的啮齿动物中，通过钝性分离颈部肌肉暴露硬脑膜，可将套管插入枕大池（CM）。该套管由细斜面针或硼硅酸盐毛细管组成，通过聚乙烯（PE）管连接到注射器。然后使用注射泵，可将分子以可控速率直接注入与蛛网膜下腔相通的枕大池。从蛛网膜下腔，我们可以通过对流追踪脑脊液流入穿透性小动脉周围的血管周围间隙，溶质在该间隙与细胞间液（ISF）进行交换。CMc可在手术后立即进行急性注射，也可用于慢性植入，随后在麻醉或清醒、自由活动的啮齿动物中进行注射。根据注射分子的物理化学性质，可通过落射荧光、双光子显微镜和磁共振成像（MRI）对脑实质中的示踪剂分布进行定量。因此，CMc结合各种成像技术为评估类淋巴系统以及脑脊液动力学和功能提供了强大的工具。此外，CMc可用作快速、全脑递送信号分子和代谢底物的通道，否则这些分子无法穿过血脑屏障（BBB）。
