The barrier between the blood and the ventricular cerebrospinal fluid (CSF) is located at the choroid plexuses. At the interface between two circulating fluids, these richly vascularized veil-like structures display a peculiar morphology explained by their developmental origin, and fulfill several functions essential for CNS homeostasis. They form a neuroprotective barrier preventing the accumulation of noxious compounds into the CSF and brain, and secrete CSF, which participates in the maintenance of a stable CNS internal environment. The CSF circulation plays an important role in volume transmission within the developing and adult brain, and CSF compartments are key to the immune surveillance of the CNS. In these contexts, the choroid plexuses are an important source of biologically active molecules involved in brain development, stem cell proliferation and differentiation, and brain repair. By sensing both physiological changes in brain homeostasis and peripheral or central insults such as inflammation, they also act as sentinels for the CNS. Finally, their role in the control of immune cell traffic between the blood and the CSF confers on the choroid plexuses a function in neuroimmune regulation and implicates them in neuroinflammation. The choroid plexuses, therefore, deserve more attention while investigating the pathophysiology of CNS diseases and related comorbidities.

血液和脑室脑脊液（CSF）之间的屏障位于脉络丛。在两种循环液之间的界面处，这些血管丰富的面纱状结构显示出一种特殊的形态，这些形态可以通过它们的发育起源加以解释，并履行中枢神经系统稳态所必需的几种功能。它们形成神经保护屏障，阻止有害化合物积聚到脑脊液和大脑中，并分泌脑脊液，从而参与维持稳定的中枢神经系统内部环境。CSF循环在发育中的大脑和成人大脑中的体积传递中起着重要作用，而CSF隔室是中枢神经系统免疫监视的关键。在这些情况下，脉络膜丛是参与大脑发育的生物活性分子的重要来源，干细胞的增殖和分化，以及脑修复。通过感知大脑动态平衡和周围或中枢性损伤（例如炎症）的生理变化，它们还充当中枢神经系统的前哨。最后，它们在控制血液和CSF之间的免疫细胞运输中的作用赋予脉络丛神经调节神经免疫功能，并牵涉到神经炎症。因此，在研究中枢神经系统疾病和相关合并症的病理生理学时，脉络丛必须引起更多关注。它们在控制血液和CSF之间的免疫细胞运输中的作用赋予脉络丛神经调节神经免疫功能，并牵涉到神经发炎。因此，在研究中枢神经系统疾病和相关合并症的病理生理学时，脉络丛必须引起更多关注。它们在控制血液和CSF之间的免疫细胞运输中的作用赋予脉络丛神经调节神经免疫功能，并牵涉到神经发炎。因此，在研究中枢神经系统疾病和相关合并症的病理生理学时，脉络丛必须引起更多关注。