Document Detail


Estrogen facilitates induction of long term potentiation in the hippocampus of awake rats.
MedLine Citation:
PMID:  9459564     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
In order to test the hypothesis that circulating levels of estrogen modulate synaptic plasticity in the hippocampus, we have studied the induction of long term potentiation (LTP) in awake rats. Ovariectomized animals, chronically implanted with a recording electrode in the cell body layer of CA1 and a stimulating electrode in stratum radiatum, were used to record evoked field potentials (population spike (PS) and summed EPSP) daily for at least 4 days before injection of sesame oil or 100 microg of estradiol benzoate per kg b.w. (E2). Basal levels of response to single square pulses (0.01 ms pulse width) delivered at 0.05 Hz through the stimulating electrode were recorded daily for 2 days after injection. To induce LTP a high-frequency 'theta pattern' stimulation was administered. Basal recordings at low-frequency stimulation did not change after injection. After high-frequency stimulation all (7/7) E2 injected animals showed LTP whereas only 1/6 oil injected controls did so; the mean increase in amplitude of the PS and slope of the EPSP after high-frequency stimulation were significantly greater in E2 treated rats. Input/output curves did not change significantly after E2 administration. These results show that at low-frequency stimulation, transynaptic responses of pyramidal neurones in CA1 are not affected by changes in levels of circulating estrogen, while synaptic plasticity -- which is at the basis of proposed hebbian associative memory -- is facilitated by estrogen treatment.
Authors:
D A Córdoba Montoya; H F Carrer
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Brain research     Volume:  778     ISSN:  0006-8993     ISO Abbreviation:  Brain Res.     Publication Date:  1997 Dec 
Date Detail:
Created Date:  1998-03-03     Completed Date:  1998-03-03     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0045503     Medline TA:  Brain Res     Country:  NETHERLANDS    
Other Details:
Languages:  eng     Pagination:  430-8     Citation Subset:  IM    
Affiliation:
Instituto de Investigación Médica Mercedes y Martín Ferreyra, Córdoba, Argentina.
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MeSH Terms
Descriptor/Qualifier:
Animals
Consciousness
Estradiol / pharmacology*
Excitatory Postsynaptic Potentials / physiology
Female
Hippocampus / drug effects,  physiology*
Long-Term Potentiation / drug effects*
Memory / drug effects
Neuronal Plasticity / drug effects
Ovariectomy
Rats
Rats, Wistar
Chemical
Reg. No./Substance:
50-28-2/Estradiol

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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