ABSTRACT
The blood-brain barrier consists of two distinct structures. The first one is the endothelium of the meningeal capillaries, characterised by tight junctions between the endothelial cells. The relative lack of pinocytosis vesicles reflects the low transcytosis activity of these cells. The second structure is the choroid plexus that produce the cerebrospinal fluid (CSF) and are located in the ventricles. They are made of epithelial cells with tight junctions that lie on the basal membrane and are associated with a fenestrated endothelium [1,2].
