Immunoreactivity for intracellular androgen receptors in identified subpopulations of neurons, astrocytes and oligodendrocytes in primate prefrontal cortex.

Sex differences in and hormone malleability of a variety of cognitive and mnemonic functions suggest that the association cortices in human and nonhuman primates are targets of gonadal hormone stimulation. One mechanism involved in this stimulation may be genomic actions mediated by intracellular androgen receptors. To identify potential cellular targets of this influence, single- and double-labeling immunohistochemical methods were used to precisely localize androgen receptor proteins in the prefrontal association cortex of adult rhesus monkeys. In both the dorsolateral and orbitofrontal regions, receptor antibodies labeled substantial populations of small intensely immunoreactive nuclei, as well as much larger and less strongly immunoreactive nuclei in all major cellular layers and/or in underlying white matter. Double-labeling studies revealed that large and small immunolabeled nuclei were further distinguished by colocalization with different classes of cell-specific markers. Whereas the large, pale receptor-immunoreactive nuclei colocalized with immunomarkers for neurons, the small, strongly immunoreactive nuclei colocalized exclusively with glial markers. Among androgen receptor-immunoreactive glia, a majority were immunoreactive for astrocyte markers, with smaller numbers of nuclei colocalized with oligodendrocyte markers; immunolabels for microglia failed to colocalize with androgen receptor immunoreactivity. This discovery of an unexpectedly large population of androgen receptor bearing glia suggests that direct functional interactions between endocrine signaling pathways and glial cells such as those coming into view in studies in subcortical and allocortical structures may also take place in the cerebral cortex and contribute to gonadal hormone stimulation of cortical processing of cognitive information. Copyright 1999 John Wiley & Sons, Inc.