The blood-brain barrier is located at the brain capillary endothelial cell level, whereas the blood-cerebrospinal
fluid barrier is located at the choroid plexus epithelial cell level. These two cellular interfaces impede the entry of numerous compounds in brain including drugs,. They also regulate immune
cell infiltration into the brain. Nowadays, researches are conducted to better understand the cell and molecular mechanisms which regulate the permeability of these barriers.
Mouse brain capillaryunder confocal microscopy
Endothelial cells / Astrocyte endfeet
Picture given by Gilles Bonvento, UNRS UPR 646, Faculté de Médecine Lariboisière St Louis, Paris