| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Submitted on June 8, 2004
Accepted on October 5, 2004
AND 17
ISOMERS OF ESTRADIOL BOTH INDUCE RAPID SPINE SYNAPSE FORMATION IN THE CA1 HIPPOCAMPAL SUBFIELD OF OVARIECTOMIZED FEMALE RATS
Center for Neural Recovery and Rehabilitation Research, Helen Hayes Hospital, West Haverstraw, New York; Departments of Obstetrics, Gynecology and Reproductive Sciences and Neurobiology , Yale University School of Medicine, New Haven, CT; Department of Psychology, Hunter College of CUNY, New York; and Laboratory of Molecular Neurobiology , Biological Research Center, Hungarian Academy of Sciences, Szeged, Hungary
* To whom correspondence should be addressed. E-mail: macluskyn{at}helenhayeshosp.org.
Previous studies have demonstrated that estradiol-17
and estradiol-17
both induce short-latency effects on spatial memory in rats, estradiol-17 being at least as potent as its 17 isomer. To determine whether the mechanisms underlying these behavioral responses might include effects on hippocampal synaptic plasticity, CA1 pyramidal spine synapse density (PSSD) was measured in ovariectomized rats within the first few hours after sc estrogen injection. PSSD increased markedly (by 24%), 4.5 h after the administration of 45 µg/kg estradiol-17. The PSSD response was significantly greater (44% above control), 30 min after estradiol-17 injection; and was markedly dose-dependent: a 3-fold lower estradiol-17 dose (15 µg/kg) did not significantly affect CA1 PSSD, at either 30 min or 4.5 h. Estradiol-17 was a more potent inducer of PSSD than estradiol-17. Dose-response analysis determined an ED50 for the effect of estradiol-17 on PSSD of 8.92 ± 1.99 µg/kg, with a maximal response at 15 µg/kg. These results demonstrate that high doses of estradiol induce rapid changes in CA1 PSSD. CA1 spine synapse formation appears to be more sensitive to estradiol-17 than to estradiol-17, paralleling previous data on the effects of these two steroids on spatial memory. Rapid remodeling of hippocampal synaptic connections may thus contribute to the enhancement of spatial mnemonic processing observed within the first few hours after estrogen treatment. The potency of estradiol-17 suggests that hormone replacement therapy (HRT) using this steroid might be useful clinically, in ameliorating the impact of low endogenous estrogen production on the development and progression of neurodegenerative disorders involving the hippocampus.
This article has been cited by other articles:
 |
|
 |
|
  E. Csakvari, A. Kurunczi, Z. Hoyk, A. Gyenes, F. Naftolin, and A. Parducz Estradiol-Induced Synaptic Remodeling of Tyrosine Hydroxylase Immunopositive Neurons in the Rat Arcuate Nucleus Endocrinology, August 1, 2008; 149(8): 4137 - 4141. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. Leranth, K. Szigeti-Buck, N. J. MacLusky, and T. Hajszan Bisphenol A Prevents the Synaptogenic Response to Testosterone in the Brain of Adult Male Rats Endocrinology, March 1, 2008; 149(3): 988 - 994. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. M. McCARTHY Estradiol and the Developing Brain Physiol Rev, January 1, 2008; 88(1): 91 - 134. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H. Ish, T. Tsurugizawa, M. Ogiue-Ikeda, M. Asashima, H. Mukai, G. Murakami, Y. Hojo, T. Kimoto, and S. Kawato Local Production of Sex Hormones and Their Modulation of Hippocampal Synaptic Plasticity Neuroscientist, August 1, 2007; 13(4): 323 - 334. [Abstract] [PDF]
|
|
|
|
 |
|
 R. Paulmurugan and S. S. Gambhir An intramolecular folding sensor for imaging estrogen receptor-ligand interactions PNAS, October 24, 2006; 103(43): 15883 - 15888. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
V. L. Adams, R. L. Goodman, A. K. Salm, L. M. Coolen, F. J. Karsch, and M. N. Lehman Morphological Plasticity in the Neural Circuitry Responsible for Seasonal Breeding in the Ewe Endocrinology, October 1, 2006; 147(10): 4843 - 4851. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. J. MacLusky, T. Hajszan, J. A. Johansen, C. L. Jordan, and C. Leranth Androgen Effects on Hippocampal CA1 Spine Synapse Numbers Are Retained in Tfm Male Rats with Defective Androgen Receptors Endocrinology, May 1, 2006; 147(5): 2392 - 2398. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. Hajszan and N. J. MacLusky Neurologic links between epilepsy and depression in women: Is hippocampal neuroplasticity the key? Neurology, March 28, 2006; 66(66_suppl_3): S13 - S22. [Abstract] [Full Text]
|
|
|
|
 |
|
 C. C. Smith and L. L. McMahon Estrogen-Induced Increase in the Magnitude of Long-Term Potentiation Occurs Only When the Ratio of NMDA Transmission to AMPA Transmission Is Increased J. Neurosci., August 24, 2005; 25(34): 7780 - 7791. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| Endocrinology | Endocrine Reviews | J. Clin. End. & Metab. |
| Molecular Endocrinology | Recent Prog. Horm. Res. | All Endocrine Journals |
