The dual action of estrogen hypothesis

Abstract

Estradiol can act in the brain in a relatively fast manner (i.e. seconds to minutes) usually through signaling initiated at the cell membrane. Brain-derived estradiol has thus been considered as another type of neurotransmitter. Recent work found that behaviors indicative of male sexual motivation are activated by estrogenic metabolites of testosterone (T) in a fast manner while sexual performance (copulatory behavior per se) is regulated by brain estradiol in a slower manner via nuclear-initiated actions. This functional division between these two types of action appears to generalize to other behavioral systems regulated by estradiol. We propose the Dual Action Hypothesis of Estrogen Action to explain this functional distinction between these two different modes of action.

Non-ovarian aromatization is required to activate female sexual motivation in testosterone-treated ovariectomized quail

“…Interestingly, changes in AA and/or estradiol concentrations have been identified in different brain regions of males a few minutes after stress (Dickens et al, 2011; Dickens et al, 2014), aggressive interactions (Charlier et al, 2011) or hearing song (Remage-Healey et al, 2008). Together these results strongly suggest that central aromatization of testosterone controls both the motivational and performance aspects of male sexual behavior and that these controls operate in different time-scales, short- and long-term (Cornil et al, 2015). Aromatase is thus a key-enzyme in the short- and long-term control of different behaviors, at least in males.…”

Medial Preoptic Regulation of the Ventral Tegmental Area Related to the Control of Sociosexual Behaviors

“…Based on additional, more refined experiments, Everitt (1990) argued that mechanisms controlling sexual arousal and copulatory behavior were separate, with mPOA regulating the consummatory sexual behaviors whereas the ventral striatal system would regulate sexual motivation. However, since then, there has been accumulating evidence indicating that POM also plays a role in appetitive sexual behavior in male quail (Balthazart et al, 1998; Tlemçani et al, 2000; Taziaux et al, 2006; Iyilikci et al, 2014; Cornil et al, 2015). For example, in vivo microdialysis in the mPOA demonstrated an increase in extracellular dopamine (DA) activity during precopulatory exposure to female conspecifics in male quail (Kleitz-Nelson et al, 2010) and rats (Hull et al, 1995).…”

Sex Hormones and Alzheimer’s Disease

“…This neuroestrogen plays major roles in sexual differentiation of brain in both male and female. Four natural types of estrogens exist: estrone (E1; a weak estrogen and the main postmenopausal type), estradiol (E2; the most potent endogenous estrogen and the main type during the reproductive age), estriol (E3; very weak estrogen and hardly detected in non-pregnant females) and estetrol (E4; secreted only during pregnancy) [41].…”