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Postnatal changes in the number of astrocytes, oligodendrocytes, and microglia in the visual cortex (area 17) of the macaque monkey: A stereological analysis in normal and monocularly deprived animals
Author(s) -
O'Kusky John,
Colonnier Marc
Publication year - 1982
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.902100309
Subject(s) - stereology , macaque , biology , microglia , cortex (anatomy) , visual cortex , anatomy , neuroscience , cerebral cortex , endocrinology , inflammation , immunology
The numerical densities (N v ) of astrocytes, oligodendrocytes, and microglia were measured in indvidual laminae of the striate cortex of macaque monkeys ranging in age from newborn to adult. Using measurements of cortical thickness and surface area, the total number of cells in the striate cortex of one hemisphere was derived for each glial cell type. Normal monkeys were compared at 3 months and 6 months of age to animals reared from birth with a monocular eyelid suture. No significant differences were observed between normal and monocularly deprived monkeys. The combined data from these groups, however, demonstrated several significant developmental changes. The N v of astrocytes decreased from birth to 6 months of age and susequently increased in the adult. The greatest changes were seen in the more superficial laminae. These changes, however, were only a response to a substantial overshoot in cortical volume at six months: the total number of astrocytes in the striate cortex did not change. There was a tenfold increase in both the N v and the total number of oligodendrocytes from birth to maturity with a corresponding increase in the density of myelinated axons. The greatest changes were observed in the deeper laminae. The total number of microglia remained relatively constant from birth to 6 months of age. There was a 55% reduction in the number of microglia in the adult, although statistical analysis indicated that this decrease was only of borderline significance. The possible relationships between these postnatal changes in glial cell numbers and the development of neuronal connectivity are discussed.