Transport across the choroid plexus epithelium.
The choroid plexus epithelium is a secretory epithelium par excellence. However, this is perhaps not the most prominent reason for the massive interest in this modest-sized tissue residing inside the brain ventricles. Most likely, the dominant reason for extensive studies of the choroid plexus is the identification of this epithelium as the source of the majority of intraventricular cerebrospinal fluid. This finding has direct relevance for studies of diseases and conditions with deranged central fluid volume or ionic balance. While the concept is supported by the vast majority of the literature, the implication of the choroid plexus in secretion of the cerebrospinal fluid was recently challenged once again. Three newer and promising areas of current choroid plexus-related investigations are as follows:1) the choroid plexus epithelium as the source of mediators necessary for central nervous system development,2) the choroid plexus as a route for microorganisms and immune cells into the central nervous system, and3) the choroid plexus as a potential route for drug delivery into the central nervous system, bypassing the blood-brain barrier. Thus, the purpose of this review is to highlight current active areas of research in the choroid plexus physiology and a few matters of continuous controversy.
Department of Biomedicine, Health, Aarhus University, Aarhus, Denmark; and jp@biomed.au.dk.
Jeppe
http://orcid.org/0000-0001-6109-247X
J
Praetorius
Department of Biomedicine, Health, Aarhus University, Aarhus, Denmark; and.|Department of Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
Helle Hasager
HH
Damkier
D000818:Animals; D001692:Biological Transport; D001812:Blood-Brain Barrier; D002555:Cerebrospinal Fluid / Q000502:physiology*; D002831:Choroid Plexus / Q000502:physiology* / Q000648:ultrastructure; D004848:Epithelium / Q000502:physiology*; D015870:Gene Expression; D006801:Humans; D006863:Hydrogen-Ion Concentration; D018799:Intercellular Adhesion Molecule-1 / Q000134:cerebrospinal fluid / Q000235:genetics; D007473:Ion Channels / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D049990:Membrane Transport Modulators / Q000494:pharmacology; D015398:Signal Transduction / Q000502:physiology*; D019010:Vascular Cell Adhesion Molecule-1 / Q000134:cerebrospinal fluid / Q000235:genetics
C573420:ICAM1 protein, human; D007473:Ion Channels; D049990:Membrane Transport Modulators; D019010:Vascular Cell Adhesion Molecule-1; D018799:Intercellular Adhesion Molecule-1
barrier function; cerebrospinal fluid; choroid plexus; fluid secretion; vectorial transport