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Effects of age on the glial cells in the rhesus monkey optic nerve
Author(s) -
Sandell Julie H.,
Peters Alan
Publication year - 2002
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.10162
Subject(s) - optic nerve , biology , myelin , neuroglia , optic tract , microglia , anatomy , population , pathology , white matter , electron microscope , nerve fiber , neuroscience , central nervous system , medicine , magnetic resonance imaging , immunology , physics , environmental health , optics , inflammation , radiology
The optic nerve is a circumscribed white matter tract consisting of myelinated nerve fibers and neuroglial cells. Previous work has shown that during normal aging in the rhesus monkey, many optic nerves lose some of their nerve fibers, and in all old optic nerves there are both myelin abnormalities and degenerating nerve fibers. The present study assesses how the neuroglial cell population of the optic nerve is affected by age. To address this question, optic nerves from young (4–10 years) and old (27–33 years) rhesus monkeys were examined by using both light and electron microscopy. It was found that with age the astrocytes, oligodendrocytes, and microglia all develop characteristic cytoplasmic inclusions. The astrocytes hypertrophy and fill space vacated by degenerated nerve fibers, and they often develop abundant glial filaments in their processes. Oligodendrocytes and microglial cells both become more numerous with age, and microglial cells often become engorged with phagocytosed debris. Some of the debris can be recognized as degenerating myelin, and in general, the greater the loss of nerve fibers, the more active the microglial cells become. J. Comp. Neurol. 445:13–28, 2002. © 2002 Wiley‐Liss, Inc.