QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

HOME  |   SEARCH  |   ARCHIVE  |   SUBSCRIBE  |   CONTACT  |   HELP

This Article Full Text Full Text (PDF) Submit an eLetter Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via ISI Web of Science (47) Citing Articles via Google Scholar Google Scholar Articles by Calizo, L. H. Articles by Flanagan-Cato, L. M. Search for Related Content PubMed PubMed Citation Articles by Calizo, L. H. Articles by Flanagan-Cato, L. M.

 Previous Article  |  Next Article 

The Journal of Neuroscience, February 15, 2000, 20(4):1589-1596

Estrogen Selectively Regulates Spine Density within the Dendritic Arbor of Rat Ventromedial Hypothalamic Neurons

Lyngine H. Calizo¹ and Loretta M. Flanagan-Cato²

¹ Institute of Neurological Sciences and ² Department of Psychology, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6074

Estrogen acts in the hypothalamic ventromedial nucleus (VMH) to promote female sexual behavior. One potential mechanism through which estrogen may facilitate this behavior is by reconfiguring synaptic connections within the VMH. Estrogen treatment increases the number of synapses and dendritic spines in the VMH, but how this remodeling occurs within the context of the local, behaviorally relevant microcircuitry is unknown. The goal of this study was to localize estrogen-induced changes in spine density within the VMH and relate these to dendritic morphology and the presence of nuclear estrogen receptor. The hypothalami from ovariectomized rats, treated with either vehicle or estradiol, were lightly fixed, and VMH neurons were iontophoretically filled with Lucifer yellow. Confocal microscopy was used to examine neuronal morphology. Estrogen treatment increased dendritic spine density by 48% in the ventrolateral VMH but had no effect on spine density in the dorsal VMH. The primary dendrites of VMH neurons were differentially affected by estrogen. Estrogen treatment increased spine density twofold on the short primary dendrites but did not affect spine density on long primary dendrites. Immunocytochemical staining showed that none of the filled neurons expressed estrogen receptor-. Thus, although the effect of estrogen on spine density is localized to a VMH subdivision where estrogen receptor is expressed, estrogen treatment induces spines on neurons that lack estrogen receptor. Taken together, our results suggest that the effect of estrogen on ventrolateral VMH spines is selective within the dendritic arbor of a neuron and may be mediated by an indirect, possibly transynaptic, mechanism.

Key words: dendritic spines; estrogen; female sexual behavior; lordosis; Lucifer yellow cell filling; VMH

---

Copyright © 2000 Society for Neuroscience  0270-6474/00/2041589-08$05.00/0

Home  |   Search  |   Archive  |   Subscribe  |   Contact  |   Help