Toxicology Research Today is a free monthly online journal that collates and summarizes the latest research about Toxicology, including details on forensic toxicology, carcinogenicity, assays. | ||||||||
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Acute Effects of Estrogen on Neuronal Physiology.Woolley CS Department of Neurobiology and Physiology, Northwestern University, Evanston, IL 60208 cwoolley@northwestern.edu. It has been known for more than 30 years that estrogen can alter the intrinsic and synaptic physiology of neurons within minutes. The physiological significance of these acute effects has been unclear, however, because some effects require higher concentrations of estrogen than are detected in plasma, and because estrogen secreted by the ovary rises and falls over a time course of days, not minutes. These concerns may be answered by new research demonstrating that estrogen is produced at high levels within the brain itself, and that production of estrogen in the brain may be regulated by neuronal activity. Additionally, recent studies indicate that classical estrogen receptor proteins are found not only in the nucleus where they regulate gene expression but also at extranuclear sites, including at synapses. These findings, together with evidence for new types of extranuclear estrogen receptors, suggest that estrogen might act directly at synapses to activate second messenger signaling, thereby rapidly altering neuronal excitability, synaptic transmission, and/or synaptic plasticity. Expected online publication date for the Annual Review of Pharmacology and Toxicology Volume 47 is January 6, 2007. Please see http://www.annualreviews.org/catalog/pub_dates.asp for revised estimates. Published 21 August 2006 in Annu Rev Pharmacol Toxicol.
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