Blood- and Cerebrospinal Fluid-Dominated Compartments of the Rat Brain
Structural integrity and proper function of the brain depend on the special environment of cerebrospinal fluid (CSF). It is partly produced by the choroid plexus, partly an ultrafiltrate resulting from transport processes across brain capillary endothelia and a product of brain metabolism. Like a mosaic, the CSF compartment is composed of innumerable microcompartments (Chesler 1990), structurally supported by glial processes. The special milieu of the brain is secured by the blood—brain barrier (BBB) and the blood—CSF barriers at the border of the neurohemal regions of circumventricular organs (CVOs). Devoid of a BBB, they are dominated by a hemal environment. Being early derivatives of the brain vesicle, all CVOs are located in the embryonic midsagittal plane. This origin from structures of the midsagittal plane within a bilaterally symmetric general morphologic pattern of the brain is reflected by the persistent thin ventricular wall in areas occupied by CVOs. These areas are only secondarily augmented by ingrowing, newly developing commissures. Due to this particular structure of the ventricular wall all CVOs and their neurohemal regions are interposed between inner (ventricular) and outer (leptomeningeal) CSF compartments (see Leonhardt 1980).
KeywordsGlial Fibrillary Acidic Protein Perivascular Space Area Postrema Pineal Organ Circumventricular Organ
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- Didier M, Harandi M, Aguera M, Bancel B, Tardy M, Fages C, Calas A, Stagaard M, Møllgård K, Belin MF (1986) Differential immunocytochemical staining for glia fibrillary acidic (GFA) protein, S-100 protein and glutamine synthetase in the rat subcommissural organ, nonspecialized ventricular ependyma and adjacent neuropil. Cell Tissue Res 245: 343–351PubMedCrossRefGoogle Scholar
- Krisch B, Leonhardt H (1989) Relations between leptomeningeal compartments and the neurohemal regions of cireumventricular organs. Biomedical Res 10 (3): 155–168Google Scholar
- Rodríguez EM, Oksche A, Rodríguez S, Hein S, Peruzzo B, Schoebitz K, Herrera H (1986) The subcommissural organ–Reissner’s fiber unit. In: Gross PM (ed) Circumventricular organs and body fluids, vol II. CRC Press, Boca Raton, pp 3–42Google Scholar