The Blood-CSF Barrier in Culture: Development of a Primary Culture and Transepithelial Transport Model from Choroidal Epithelial Cells

The chemical stability of the central nervous system (CNS) is safeguarded by two major barrier systems that separate the systemic circulation from the cerebral compartment. Within the cerebral compartment, the interstitial fluid (ISF) flows between neurons and the cerebrospinal fluid (CSF) circulates among major brain structures and ventricles. The direct continuity of ISF and CSF allows for the free exchange of substances within the extracellular space of the cerebral compartment. Thus, the barrier that separates the systemic compartment from ISF is defined as the blood-brain barrier, while the one that discontinues the circulation between systemic and CSF compartments is named the blood-CSF barrier. The choroid plexus, located within brain ventricles, is the tissue where the blood-CSF barrier is formed (1 ).