In:
Endocrinology, The Endocrine Society, Vol. 149, No. 7 ( 2008-07-01), p. 3306-3312
Abstract:
Immunocytochemical studies have shown that nuclear and extranuclear estrogen receptors (ERs) are present in several extrahypothalamic brain regions. The goal of this study was to determine the subcellular location of functional ERs, particularly extranuclear ERs, by demonstrating 125I-estradiol binding in the rat forebrain and medullary sections prepared for light and electron microscopic autoradiography. Some sections were immunocytochemically labeled with the catecholamine-synthesizing enzyme, tyrosine hydroxylase (TH), prior to the autoradiographic procedure. By light microscopy, dense accumulations of silver grains denoting 125I-estradiol binding were observed over cells in the ventromedial and arcuate hypothalamic nuclei, amygdala, and nucleus of the solitary tract. In sections labeled for TH, large accumulations of silver grains were admixed with TH-labeled processes in the medial nucleus of the amygdala and over TH-labeled perikarya in the medial and commissural nucleus of the solitary tract. Electron microscopic analyses were focused on the rostral ventrolateral medulla and the hippocampal CA1 region, two regions previously shown to have extranuclear ERs. In the rostral ventrolateral medulla, silver grains indicative of 125I-estradiol binding were found within a few large terminals, affiliated with mitochondria. In the hippocampus, autoradiographic silver grains denoting 125I-estradiol binding were associated with mitochondria in dendritic shafts or were near synaptic specializations on dendritic spines. These patterns of silver grain labeling were not seen in sections from rats that received 125I-estradiol combined with cold estradiol. The association of 125I-estradiol binding with pre- and postsynaptic profiles supports a functional role for nonnuclear ERs in brain.
Type of Medium:
Online Resource
ISSN:
0013-7227
,
1945-7170
DOI:
10.1210/en.2008-0307
Language:
English
Publisher:
The Endocrine Society
Publication Date:
2008
detail.hit.zdb_id:
2011695-0
