Female sexual behaviors in rodents (lordosis and appetitive or "proceptive" behaviors) are induced through a genomic mechanism by the sequential actions of estradiol (E2) and progesterone (P), or E2 and testosterone (T) at their respective receptors. However, non-steroidal agents, such as gonadotropin-releasing hormone (GnRH), Prostaglandin E2 (PGE2), noradrenaline, dopamine, oxytocin, α-melanocyte stimulating hormone, nitric oxide, leptin, apelin, and others, facilitate different aspects of female sexual behavior through their cellular and intracellular effects at the membrane and genomic levels in ovariectomized rats primed with E2. These neurotransmitters often act as intermediaries of E2 and P (or T). The classical model of steroid hormone action through intracellular receptor binding has been complemented by an alternative scenario wherein the steroid functions as a transcription factor after binding the receptor protein to DNA. Another possible mechanism occurs through the activation of second messenger systems (cyclic AMP, cyclic GMP, calcium), which subsequently initiate phosphorylation events via diverse kinase systems (protein kinases A, G, or C). These kinases target the progesterone receptor (PR) or associated effector proteins that connect the PR to the trans-activation machinery. This may also happen to the androgen receptor (AR). In addition, other cellular mechanisms could be involved since the chemical structure of these non-steroidal agents causes a change in their lipophobicity that prevents them from penetrating the cell and exerting direct transcriptional effects; however, they can exert effects on different components of the cell membrane activating a cross-talk between the cell membrane and the regulation of the transcriptional mechanisms.

Center for Sexual Health and Intervention Czech National Institute of Mental Health Klecany 25067 Czech Republic; Department of Psychology and Life Sciences Faculty of Humanities Charles University Prague 18200 Czech Republic

Centro de Investigación de Investigación en Reproducción Animal Universidad Autónoma de Tlaxcala CINVESTAV Tlaxcala México

Centro de Investigación de Investigación en Reproducción Animal Universidad Autónoma de Tlaxcala CINVESTAV Tlaxcala México; Licenciatura en Ingeniería Agronómica y Zootecnia Complejo Regional Centro Benemérita Universidad Autónoma de Puebla Puebla México

Centro Tlaxcala de Biología de la Conducta Universidad Autónoma de Tlaxcala Tlaxcala México

Facultad de Ciencias para el Desarrollo Humano Universidad Autónoma de Tlaxcal México

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