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Scanning electron microscopy of the subarachnoid space in the dog. III. Cranial levels
Author(s) -
Allen Delmas J.,
Low Frank N.
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.901610404
Subject(s) - subarachnoid space , scanning electron microscope , transmission electron microscopy , electron microscope , morphology (biology) , anatomy , extracellular , pathology , materials science , microscopy , perivascular space , biology , nanotechnology , medicine , optics , composite material , physics , cerebrospinal fluid , microbiology and biotechnology , genetics
Young dogs were anesthetized by intrathoracic injection of sodium pentobarbital and perfused with buffered aldehydes. Lining tissue samples from the cranial subarachnoid space were prepared for scanning electron microscopy (SEM) by postfixing in buffered OsO 4 . Samples were then dehydrated, dried in a Critical Point Drying System, and coated with carbon and palladiumgold. Specimens were viewed in a Cambridge S4 scanning electron microscope. After thorough scanning, selected samples were routinely prepared for transmission electron microscopy (TEM) and viewed in a Philips EM‐200 transmission electron microscope. This study depicts the surface morphology of the meningeal linings of the cranial subarachnoid space. The cranial pia mater possesses natural gaps or fenestrations between cells. SEM reveals a more complex morphology of arachnoid trabeculae than previously interpreted from light and transmission electron microscopy. Many free cells are observed on the meningeal linings of the subarachnoid space. The present study establishes that these free cells are macrophages by means of definitive TEM correlates. Microvillous‐like processes extending between macrophages and the pial surface are present. The frequency and the nature of these thin processes suggest the possibility of a plasmalemmamediated system of communication.