Fig. 1.

Schematic drawing showing some features of the perivascular astrocytic end feet, which form ‘rosette’-like structures on the brain capillary surface. This arrangement would be expected to be optimal for two-way induction and communication between the astrocytes and endothelium, while not forming a physical barrier, so preserving free diffusion between the endothelium and the brain parenchyma. Based on Kacem et al. (1998).