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Junctions in the meninges and marginal glia
Author(s) -
Nabeshima Sachio,
Reese T. S.,
Landis Dennis M. D.,
Brightman M. W.
Publication year - 1975
Publication title -
journal of comparative neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.855
H-Index - 209
eISSN - 1096-9861
pISSN - 0021-9967
DOI - 10.1002/cne.901640202
Subject(s) - meninges , tight junction , subarachnoid space , gap junction , cerebrospinal fluid , anatomy , intramembranous ossification , pia mater , biology , septate junctions , blood–brain barrier , perivascular space , dura mater , cell junction , pathology , neuroscience , central nervous system , microbiology and biotechnology , intracellular , medicine , cell , genetics
Abstract The meninges of various mammals were prepared for examination with the electronmicroscope by thin sectioning or freeze‐fracturing. Particular attention was given to the distribution of tight junctions in order to determine the basis for the meningeal barrier between the blood circulating in dural vessels and the cerebrospinal fluid in the subarachnoid space. While some dural blood vessels are fenestrated, those in the subarachnoid space are not and their component endothelial cells are joined by an extensive system of tight junctions. An extensive and continuous system of tight junctions was also found in a layer of specialized cells at the border of the arachnoid with the dura. This arachnoid barrier layer is apparently the only basis of the meningeal barrier because often cellular layers in the dura and arachnoid lack tight junctions although they are linked by gap junctions and desmosomes. In particular, tight junctions are lacking at the border of the “subdural space” which is actually a fascial plane within the dura. Tight junctions are also lacking between astrocytes at the surface of the brain but these cells are linked by gap junctions and a new type of intercellular junction. The distribution of these junctions, as well as assemblies of intramembranous particles at the astrocytic border, raises the question whether this layer might have a role in the exchange of certain substances between the brain and cerebrospinal fluid.