Feminine Sexual Behavior from Neuroendocrine and Molecular Neurobiological Perspectives

Effects of gonadal steroids and of estrogen receptor agonists on the expression of estrogen receptor alpha in the medial preoptic nucleus of female rats

“…However, along the estrous cycle, the estradiol surge is followed, a few hours later, by a P surge at proestrus (Butcher et al, 1974;Smith et al, 1975). Therefore, the decrease in the total number of ERa-ir neurons that occurs at proestrus might also be a consequence of high P levels, because one of the actions of P in the preoptic area and hypothalamus, which abundantly express P receptors (Shughrue et al, 1997a;Quadros and Wagner, 2008), is to decrease estradiol binding (Brown and MacLusky, 1994;Blaustein and Mani, 2007). As in the hypothalamus, pituitary and uterus, in the preoptic area there are low concentrations of PRs in the absence of estradiol (MacLusky and McEwen, 1978).…”

“…The reason for this different sensitivity to P is not clear, although speculatively it might arise from differences in the expression of P receptors. In fact, there is evidence that P reduces the ability of cells to respond to estrogens (Brown and MacLusky, 1994;Blaustein and Mani, 2007) and, when compared to the BNST, the medial preoptic area contains significantly higher concentrations of both un-induced and estrogeninducible P receptors (Parsons et al, 1982;Brown et al, 1990).…”

“…In the MPN, ERa and ERb, although more densely concentrated in the medial division (Yuri and Kawata, 1991;Shughrue et al, 1997b;Madeira et al, 2000), are expressed along its rostrocaudal extension. There is ample evidence from the literature that ERa is essential for the modulation of the physiological mechanisms that mediate the proceptive and receptive components of female sexual behavior (for a review see Blaustein and Mani, 2007;Blaustein, 2009). It has also been demonstrated that, in the preoptic area in general and in the MPN in particular, ERa mRNA and protein levels vary across the estrous cycle, being highest at metestrus and lowest at proestrus (Shughrue et al, 1992;Zhou et al, 1995).…”

Progestin Receptor Subtypes in the Brain: The Known and the Unknown

“…As in other reproductive tissues, P modulates cellular functions in the central nervous system to coordinate physiology and reproductive functions in various species (12)(13)(14). Accumulating evidence over the past few years suggests that in addition to reproduction, P affects a wide repertoire of biological functions including aggression, maternal behavior, learning and memory, mood, and sexual differentiation (15)(16)(17)(18)(19)(20)(21)(22)(23).…”

“…Although the mechanisms of P action in these biological processes are currently being investigated, a wide body of literature exists on the molecular basis of P action in reproductive behavior in female rodents. This behavior, regulated by the sequential release of estradiol (E 2 ) and P, has remained one of the best-studied models for investigations into the P action in the brain.Although diverse cellular mechanisms have been ascribed to the P action in the brain, the primary mechanism involves its interaction with E 2 -induced, intracellular PRs that function as transcriptional factors, regulating the expression of genes and genomic neural networks to initiate and/or sustain physiological response (12)(13)(14). Spatial, temporal, and functional correlations of neural PRs established using progestin binding, autoradiography, immunohistochemistry, and in situ hybridization techniques (12, 13) identified the…”