Department of Biomedical Engineering and Physics, Amsterdam University Medical Center, Amsterdam, The Netherlands.
Amsterdam Neuroscience Research Institute, Amsterdam, Netherlands.
Sci Rep. 2024 Jul 26;14(1):17655. doi: 10.1038/s41598-024-67885-y.
The perivascular space (PVS) surrounds cerebral blood vessels and plays an important role in clearing waste products from the brain. Their anatomy and function have been described for arteries, but PVS around veins remain poorly characterized. Using in vivo 2-photon imaging in mice, we determined the size of the PVS around arteries and veins, and their connection with the subarachnoid space. After infusion of 70 kD FITC-dextran into the cerebrospinal fluid via the cisterna magna, labeled PVS were evident around arteries, but veins showed less frequent labeling of the PVS. The size of the PVS correlated with blood vessel size for both pial arteries and veins, but not for penetrating vessels. The PVS around pial arteries and veins was separated from the subarachnoid space by a thin meningeal layer, which did not form a barrier for the tracer. In vivo, FITC-dextran signal was observed adjacent to the vessel wall, but minimally within the wall itself. Post-mortem, there was a significant shift in the tracer's location within the arterial wall, extending into the smooth muscle layer. Taken together, these findings suggest that the PVS around veins has a limited role in the exchange of solutes between CSF and brain parenchyma.
血管周围间隙（PVS）环绕脑内血管，在清除大脑内废物方面发挥着重要作用。目前已经对 PVS 围绕动脉的解剖结构和功能进行了描述，但对 PVS 围绕静脉的结构和功能仍知之甚少。本研究采用活体双光子成像技术在小鼠中进行研究，确定了 PVS 围绕动脉和静脉的大小，以及 PVS 与蛛网膜下腔之间的联系。通过枕大池向脑脊液中输注 70 kD FITC-葡聚糖后，发现 PVS 在动脉周围有明显标记，但 PVS 在静脉周围的标记则不常见。PVS 的大小与小动脉和小静脉的血管大小相关，但与穿透性血管无关。小动脉和小静脉周围的 PVS 与蛛网膜下腔之间被一层薄脑膜隔开，该脑膜层不会成为示踪剂的屏障。活体观察到 FITC-葡聚糖信号位于血管壁附近，但在血管壁本身内则很少见。死后，示踪剂在动脉壁内的位置有明显的转移，延伸至平滑肌层。综上，这些发现表明 PVS 围绕静脉在 CSF 和脑实质之间溶质交换中的作用有限。
