Cellular and molecular mechanisms of action of ovarian steroid hormones II: Regulation of sexual behavior in female rodents.

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).

Cellular and molecular mechanisms of action of ovarian steroid hormones. I: Regulation of central nervous system function.

The conventional way steroid hormones work through receptors inside cells is widely acknowledged. There are unanswered questions about what happens to the hormone in the end and why there isn't always a strong connection between how much tissue takes up and its biological effects through receptor binding. Steroid hormones can also have non-traditional effects that happen quickly but don't involve entering the cell.

Disruptions in reproductive health, sex hormonal profiles, and hypothalamic hormone receptors content in females of the C58/J mouse model of autism.

Autism Spectrum Disorder (ASD) is characterized by differences in social communication and interaction, as well as areas of focused interests and/or repetitive behaviors. Recent studies have highlighted a higher prevalence of endocrine and reproductive disturbances among females on the autism spectrum, hinting at potential disruptions within the hypothalamus-pituitary-ovary (HPO) axis. This research aims to explore the reproductive health disparities in ASD using an animal model of autism, the C58/J inbred mouse strain, with a focus on reproductive performance and hormonal profiles compared to the C57BL/6J control strain.

Participation of kisspeptin, progesterone, and GnRH receptors on lordosis behavior induced by kisspeptin.

The neuropeptide kisspeptin (Kiss) is crucial in regulating the hypothalamic-pituitary-gonadal axis. It is produced by two main groups of neurons in the hypothalamus: the rostral periventricular region around the third ventricle and the arcuate nucleus. Kiss is the peptide product of the KiSS-1 gene and serves as the endogenous agonist for the GPR54 receptor.

Chronic MK-801 administration provokes persistent deficits in social memory in the prairie vole (Microtus ochrogaster): A potential animal model for social deficits of schizophrenia.

The prairie vole (Microtus ochrogaster) is a rodent species that has been used extensively to study biological aspects of human social bonding. Nevertheless, this species has not been studied in the context of modeling social deficits characteristic of schizophrenia. Building on studies in rodents that show that sub-chronic administration of an NMDA receptor antagonist induces persistent behavioral and neurological characteristics of schizophrenia, we administered MK-801 (0.

Influence of environmental enrichment on sexual behavior and the process of learning and memory in a rat model of autism with valproic acid.

Autism spectrum disorder (ASD) is a psychiatric disorder with severe behavioral consequences and no specific therapy. Its etiology is multifactorial, as it is caused by a complex interaction of genetic and environmental factors. In rats, prenatal exposure to the antiepileptic drug valproic acid (VPA) has been associated with an increased risk of autistic-like behaviors in offspring, including social behavior deficits, increased repetitive behaviors, and cognitive impairments.

Participation of the nitric oxide pathway in lordosis induced by apelin-13 in female rats.

The present study investigated the participation of the nitric oxide pathway in facilitating lordosis behavior induced by intrahypothalamic administration of apelin-13 in ovariectomized rats primed with estradiol benzoate (EB). The experiments involved the administration of a nitric oxide synthase inhibitor (L-NAME) or a nitric oxide-dependent, soluble guanylyl cyclase inhibitor (ODQ), and an inhibitor of protein kinase G (KT5823) to the ventromedial hypothalamus (VMH) of EB-primed rats 30 min before infusion of apelin-13 (0.75 μg/μl).

Estradiol and progesterone-induced lordosis behavior is modulated by both the Kisspeptin receptor and melanin-concentrating hormone in estradiol benzoate-primed rats.

Intracerebroventricular (ICV) administration of estradiol benzoate (EB) and progesterone (P) induces intense lordosis behavior in ovariectomized rats primed peripherally with EB. The present study tested the hypothesis that the Kisspeptin (Kiss) and melanin-concentrating hormone (MCH) pathways regulate female sexual behavior induced by these steroid hormones. In Experiment 1, we tested the relevance of the Kiss pathway by ICV infusion of its inhibitor, kiss-234, before administration of EB or P in estrogen-primed rats.

Apelin-13 facilitates lordosis behavior following infusions to the ventromedial hypothalamus or preoptic area in ovariectomized, estrogen-primed rats.

In normal hormonal conditions, increased neuronal activity in the ventromedial hypothalamus (VMH) induces lordosis whereas activation of the preoptic area (POA) exerts an opposite effect. In the present work, we explored the effect of bilateral infusion of different doses of the apelin-13 (0.37, 0.

Mating-induced analgesia is dependent of copulatory male pattern in high- and low- yawning male rats.

Mating behavior in rodents can modulate pain sensations in both sexes. In males, the execution of mounts, intromissions, and ejaculations induced a progressive increase in their vocalization thresholds induced by tail shocks and other types of noxious stimuli. We selectively inbred two sublines from Sprague-Dawley (SD) rats that differed in their spontaneous yawning frequency.

Oxytocin induces lordosis behavior in female rats through the prostaglandin E2/GnRH signaling system.

Intracerebroventricular (icv) administration of oxytocin (OT) induces robust lordosis behavior (lordosis quotient and lordosis intensity) in estrogen-primed rats. The present study explored the hypothesis that the OT-Prostaglandin E2-GnRH pathway (a pathway produced in astrocytes) is involved in the facilitation of lordosis behavior by icv infusion of OT (2 μg). In Experiment 1, we tested the involvement of the OT receptor (OTR) by infusion of the OTR antagonist, atosiban (ATO).

Behavioral consequences of postnatal undernutrition and enriched environment during later life.

In rat models, large litter groups during suckling are used in the study of undernutrition. Large litter sizes are known to promote alterations in memory processes and anxiety-like behavior. Nevertheless, the effect of large litter size on sexual behavior and the reproductive system is still unknown.

Tibolone induces lordosis behavior, but not concurrent or sequential inhibition, in Sprague Dawley rats.

Activation of progesterone receptor (PR) facilitates lordosis 40 hr after estradiol treatment, but induces concurrent inhibition (CI) when given with estradiol, or sequential inhibition (SI) when given subsequent to the faciliatory time interval. Tibolone (TBL) is a broad spectrum gonadal steroid agonist that facilitates lordosis when given after estradiol and in place of progesterone (P). The present experiment examined whether it can also induce CI or SI of lordosis behavior in rats as a means of determining its dominant receptor mechanism of action.

Threshold for copulation-induced analgesia varies according to the ejaculatory endophenotypes in rats.

Analgesia may be modulated by multiple internal and external factors. In prior studies, copulatory-induced analgesia was demonstrated using the vocalization threshold to tail shock (VTTS) in male and female rats. Three ejaculatory endophenotypes have been characterized in male Wistar rats based upon their ejaculation latency (EL).

Increasing the antinociceptive effect of ingested glycinamide in female rats by increasing its palatability.

Background: These studies were undertaken to investigate whether the ingestion of glycinamide, a precursor of glycine, made more palatable by mixing with a chocolate suspension, improves antinociception in rats.

Methods: Two nociception threshold models were employed: the tail-flick latency and vocalization to tail shock, in restricted and freely-moving rats. Glycinamide in a highly palatable commercial chocolate aqueous suspension was provided for ad-lib ingestion after 24 hours of water deprivation.

Tibolone facilitates lordosis behavior through estrogen, progestin, and GnRH-1 receptors in estrogen-primed rats.

A dose-response study was made of the broad-spectrum gonadal steroid agonist tibolone (TBL) on lordosis behavior in estradiol benzoate (EB: 5 µg) primed rats. Doses of TBL (0, 1, 4, and 16 μg) were infused to the right lateral ventricle 2 h before testing. The highest dose increased lordosis quotients significantly at 240 min and 360 min following infusion.

Protein kinase inhibitors infused intraventricularly or into the ventromedial hypothalamus block short latency facilitation of lordosis by oestradiol.

An injection of unesterified oestradiol (E ) facilitates receptive behaviour in E benzoate (EB)-primed, ovariectomised female rats when it is administered i.c.v.

Chronic sleep loss disrupts blood-testis and blood-epididymis barriers, and reduces male fertility.

Sleep loss increases blood-brain barrier permeability. As the blood-brain barrier and the blood-tissue barriers in the reproductive tract (blood-testis and blood-epididymis barriers) share common characteristics, we hypothesized that sleep restriction may also modify their barrier function. Previous reports showed that sleep loss decreased sperm viability and progressive fast mobility, which may be a consequence of altered blood-testis and blood-epididymis barrier.

LPA receptor activation induces PKCα nuclear translocation in glioblastoma cells.

Lysophosphatidic acid (LPA) is a ubiquitous lysophospholipid that induces a wide range of cellular processes such as wound healing, differentiation, proliferation, migration, and survival. LPA signaling is increased in a number of cancers. In Glioblastoma (GBM), the most aggressive brain tumor, autotaxin the enzyme that produces LPA and its receptor LPA are overexpressed.

Copulation-induced antinociception in female rats is blocked by atosiban, an oxytocin receptor antagonist.

Aims: We hypothesized that copulation-induced temporary anti-nociception in female rats is mediated by the activation of central and/or peripheral oxytocin receptors. To test this hypothesis, we assessed the effects of intraperitoneal (ip), intrathecal (it), and intra-cerebroventricular (icv) administration of an oxytocin receptor antagonist (atosiban), on copulation-induced temporary anti-nociception in estrous rats.

Main Methods: The treatment groups were ovariectomized rats pre-treated subcutaneously (sc) with 10 μg of estradiol benzoate (EB) followed 24 h later by an sc injection of 5 μg EB, and 4 h later, by an sc injection of 2 mg progesterone (P4).

Sex hormone levels and expression of their receptors in lactating and lactating pregnant rats.

Parturient rats show a postpartum estrus, a period of sexual receptivity that occurs from 6 to 15 h after the birth of a litter, which allows the mother to gestate a second litter while simultaneously nursing the first one (lactating and pregnant). The present study investigated hormone levels and the expression pattern of estrogen receptor α, and β, progesterone receptor isoforms and SRC1 in the hypothalamus and the preoptic area of lactating as well as in lactating-pregnant rats. In the latter, estradiol levels were 3-fold higher than those observed in lactating rats on day 14, meanwhile progesterone levels did not change in any condition.

Participation of progesterone receptors in facilitation and sequential inhibition of lordosis response induced by ring A-reduced progesterone metabolites in female mice.

Sexual receptivity in female rodents induced by the sequential injection of estrogen and progesterone is followed by a period in which females do not respond behaviorally to a second administration of progesterone (P); this is known as sequential inhibition. It has been proposed that the induction of sequential inhibition by progesterone in rats depends on down regulation of the progesterone receptor (PR) in brain areas involved in the expression of female sexual receptivity. P is rapidly metabolized to a variety of 5α- or 5β-ring A-reduced progestins (RPrg).

Estrogen receptor α and β are involved in the activation of lordosis behavior in estradiol-primed rats.

The present study was designed to assess the participation of estrogen receptors alpha (ERα) and beta (ERβ) in the short-term facilitation of lordosis behavior in ovariectomized (ovx), estradiol (E) primed rats. In experiment 1, dose response curves for PPT and DPN (ERα and ERβ agonists, respectively) facilitation of lordosis behavior (lordosis quotient and lordosis score) were established by infusing these agonists into the right lateral ventricle (icv) in female rats injected 40h previously with 5μg of E benzoate. PPT doses of 0.

The importance of the chemical structure of pregnanes in the concurrent inhibition of estrous behavior in the female rat.

An investigation of aspects ranging from behavior to molecular electronic structure and physicochemical properties was performed to explore the role of 5α-pregnanedione (5α-DHP), 5β-pregnanedione (5β-DHP) and their precursor progesterone (P) on the concurrent inhibition of the sexual lordosis response in female rats. The concurrent inhibition of lordosis behavior occurs when ovariectomized rodents are primed simultaneously with estradiol (E2) and P. Thus, a second administration of P 40h later fails to induce the expected sexual response that takes place when E2 and P are administered sequentially 40h apart.