Neuroscience 2005 Abstract
| Presentation Number: | 403.12 |
|---|---|
| Abstract Title: | Subcellular localization of progestin receptors in the rat hippocampus. |
| Authors: |
Waters, E. M.*1
; Herrick, S. P.1,2
; McEwen, B. S.1
; Milner, T. A.2
1Lab. Neuroendocrinol., Rockefeller Univ, New York, NY 2NY, 1230 York Ave, 10021, |
| Primary Theme and Topics |
Homeostatic and Neuroendocrine Systems - Neuroendocrine -- Steroids and plasticity |
| Secondary Theme and Topics | Homeostatic and Neuroendocrine Systems<br />- Neuroendocrine<br />-- Development |
| Session: |
403. Steroids and Plasticity I Poster |
| Presentation Time: | Monday, November 14, 2005 11:00 AM-12:00 PM |
| Location: | Washington Convention Center - Hall A-C, Board # AA20 |
| Keywords: | PLASTICITY, STEROID, PYRAMIDAL, DENDRITE |
In the hippocampus of female rats, steroid dependent changes in structure and function occur across the estrous cycle. Dendritic spine density is upregulated by estrogen and downregulated by progesterone. Progesterone that follows estrogen exposure rapidly decreases spine density in the CA1 region of the hippocampus and this action is blocked by the progestin receptor (PR) antagonist, RU486 (Woolley and McEwen, JCN 336: 293 – 306, 1993). Our previous studies have located immunoreactivity (-ir) for the alpha and the beta forms of the estrogen receptor in dendritic spines (Milner et al. JCN 429: 355 – 371, 2001; Milner et al., SFN, 2004). This study sought to describe the cellular and subcellular localization of PRs in the hippocampus. Coronal hippocampal sections from both proestrus and ovariectomized estrogen-replaced rats were immunolabeled with antibodies to PR and examined by light and electron microscopy. By light microscopy, PR-ir was undetectable in the hippocampal formation although PR-ir was present in nuclei within the hypothalamus and amygdala. Ultrastructural analysis of the CA1 region revealed PR-ir at several extranuclear sites. PR-ir was present in dendritic spines, many arising from pyramidal cell dendrites, and was closely associated with the postsynaptic density. PR-ir was found in axons and axon terminals that contained small synaptic vesicles. Terminals and en passant axonal boutons with PR-ir formed synapses with dendritic spines. PR-ir also was found in glia, many resembling astrocytes and some forming presumed gap junctions with other astrocytic profiles. The lack of nuclear PR-ir suggests that progesterone uses an exclusively non-genomic signaling mechanism in the hippocampus and could directly affect dendritic spine morphology and synaptic plasticity.
Supported by DA08259, NS07080
Sample Citation:
[Authors]. [Abstract Title]. Program No. XXX.XX. 2005 Neuroscience Meeting Planner. Washington, DC: Society for Neuroscience, 2005. Online.
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