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Relationship between Sexual Satiety and Brain Androgen Receptors
Abstract and Figures
Recently we showed that 24 h after copulation to satiety, there is a reduction in androgen receptor density (ARd) in the medial preoptic area (MPOA) and in the ventromedial hypothalamic nucleus (VMH), but not in the bed nucleus of the stria terminalis (BST). The present study was designed to analyze whether the ARd changes in these and other brain areas, such as the medial amygdala (MeA) and lateral septum, ventral part (LSV), were associated with changes in sexual behavior following sexual satiety. Males rats were sacrificed 48 h, 72 h or 7 days after sexual satiety (4 h ad libitum copulation) to determine ARd by immunocytochemistry; additionally, testosterone serum levels were measured in independent groups sacrificed at the same intervals. In another experiment, males were tested for recovery of sexual behavior 48 h, 72 h or 7 days after sexual satiety. The results showed that 48 h after sexual satiety 30% of the males displayed a single ejaculation and the remaining 70% showed a complete inhibition of sexual behavior. This reduction in sexual behavior was accompanied by an ARd decrease exclusively in the MPOA-medial part (MPOM). Seventy-two hours after sexual satiety there was a recovery of sexual activity accompanied by an increase in ARd to control levels in the MPOM and an overexpression of ARd in the LSV, BST, VMH and MeA. Serum testosterone levels were unmodified during the post-satiety period. The results are discussed on the basis of the similarities and discrepancies between ARd in specific brain areas and male sexual behavior.
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... ng/ml), 72 h (3.80±0.86 ng/ml) y siete días post-saciedad sexual (2.28±0.37 ng/ml) (Romano et al., 2006). ...
... Se mencionó previamente que después de la saciedad sexual, la testosterona sérica no se modifica (Romano et al., 2006), por lo que surge la duda de qué ocurre con la morfofisiología del epidídimo después de la saciedad sexual. ...
Morfologia del epididimo en condiciones de saciedad sexual
... 86 Moreover, it was observed that a reduction in sexual behavior during the refractory period was linked to a decrease in the level of androgen receptor (AR) in the MPOA, which was subsequently restored upon recovery of sexual activity. 87 In addition, reinstatement of serum testosterone in aging males led to an increase in AR levels in the MPOA. 88 In turn, AR levels were also suppressed in the MPOA of mothers. ...
The medial preoptic area (MPOA) has long been implicated in maternal and male sexual behavior. Modern neuroscience methods have begun to reveal the cellular networks responsible, while also implicating the MPOA in other social behaviors, affiliative social touch, and aggression. The social interactions rely on input from conspecifics whose most important modalities in rodents are olfaction and somatosensation. These inputs bypass the cerebral cortex to reach the MPOA to influence the social function. Hormonal inputs also directly act on MPOA neurons. In turn, the MPOA controls social responses via various projections for reward and motor output. The MPOA thus emerges as one of the major brain centers for instinctive social behavior. While key elements of MPOA circuits have been identified, a synthesis of these new data is now provided for further studies to reveal the mechanisms by which the area controls social interactions.
... Additional evidence of sexual alliesthesia comes from the response to pleasurable taste stimuli of female rats that changed cyclically with their hormonal status [50,51]. ...
troduction
Abstract
The current dictionary definition for alliesthesia is the hedonic modification of a sensation. The stimuli used to establish this initial definition was skin temperature and sweet tastes. However, accrued experimental evidence shows that changes in hedonicity place also in sensations, and then in other cognitive processes, mental experiences, and in all decision making. These accumulated data render obsolete the previous definition. We propose the following new one: Alliesthesia refers to a modified outcome of the hedonic dimension of any mental process, from sensation to mental performance, and decision making leading to physiological comfort and happiness. Positive alliesthesia is the rise in pleasure or joy or a decrease in displeasure or pain, while negative alliesthesia is the opposite.
... In male rats, sexual exhaustion is reached after several hours of repeated mating with the same female [3,4,10,55]. Depending on the particular study that is considered, investigators concluded that males had reached satiety when they displayed an absence of sexual activity for a period comprised between 30-90 min [4,6,7]. ...
... In male rats, sexual exhaustion is reached after several hours of repeated mating with the same female [3,4,10,55]. Depending on the particular study that is considered, investigators concluded that males had reached satiety when they displayed an absence of sexual activity for a period comprised between 30-90 min [4,6,7]. ...
This study was designed to determine whether changes in sexual motivation acutely regulate brain estrogen synthesis by aromatase. Five experiments (Exp.1–5) were first conducted to determine the effect of recent mating and of the presentation of a new female (Coolidge effect) on sexual motivation. Exp.1–2 showed that 10 min or overnight access to copulation decreases measures of male sexual motivation when male subjects were visually exposed to the female they had copulated with and this effect is not counteracted by the view of a new female. Exp.3 showed that sexual motivation is revived by the view of a new female in previously unmated males only allowed to see another female for 10 min. After mating for 10 min (Exp.4) or overnight (Exp.5) with a female, males showed a decrease in copulatory behavior that was not reversed by access to a new female. Exp.6 and 7 confirmed that overnight copulation (Exp.6) and view of a novel female (Exp.7) respectively decreases and increases sexual behavior and motivation. Yet, these manipulations did not affect brain aromatase activity except in the tuberal hypothalamus. Together these data confirm that copulation or prolonged view of a female decrease sexual motivation but a reactivation of sexual motivation by a new female can only be obtained if males had only seen another female but not copulated with her, which is different in some degree from the Coolidge effect described in rodents. Moreover changes in brain aromatase do not simply reflect changes in motivation and more complex mechanisms must be considered.
... Consistent with this role of estrogens, aromatase knockout mice also showed increased latencies to mount, intromit or ejaculate, and showed no partner preference at all (Bakker et al., 2002). By contrast, androgen receptor activation is much more strongly implicated in ejaculation and satiety (Romano-Torres et al., 2007;Yeh et al., 2009), and erection is also more dependent on circulating androgens than estradiol (Hull and Dominguez, 2007). ...
Testosterone is the main circulating steroid hormone in males, and acts to facilitate sexual behavior via both reduction to dihydrotestosterone (DHT) and aromatization to estradiol. The mPOA is a key site involved in mediating actions of androgens and estrogens in the control of masculine sexual behavior, but the respective roles of these hormones is not fully understood. As males age they show impairments in sexual function, and a decreased facilitation of behavior by steroid hormones compared to younger animals. We hypothesized that an anatomical substrate for these behavioral changes is a decline in expression and/or activation of hormone receptor-sensitive cells in the mPOA. We tested this by quantifying and comparing numbers of AR- and ERα-containing cells, and Fos as a marker of activated neurons, in the mPOA of mature (4-5months) and aged (12-13months) male rats, assessed one hour after copulation to one ejaculation. Numbers of AR- and ERα cells did not change with age or after sex, but the percentage of AR- and ERα-cells that co-expressed Fos were significantly up-regulated by sex, independent of age. Age effects were found for the percentage of Fos cells that co-expressed ERα (up-regulated in the central mPOA) and the percentage of Fos cells co-expressing AR in the posterior mPOA. Interestingly, serum estradiol concentrations positively correlated with intromission latency in aged but not mature animals. These data show that the aging male brain continues to have high expression and activation of both AR and ERα in the mPOA with copulation, raises the possibility that differences in relationships between hormones, behavior, and neural activation may underlie some age-related impairments.
Această carte despre dependența sexuală corespunde în primul rând unei nevoi sociale urgente. Efectele negative ale ignoranței comportamentului sexual, lipsa educației sexuale din școli, nevoia de cunoaștere și, în funcție de caz, de psihoterapie sunt doar câteva aspecte asupra cărora autorul își propune să atragă atenția în special adolescenților, tinerilor, părinților care își iubesc copiii și doresc să îi înțeleagă. Definirea adicției sexuale ca o tulburare, înțelegerea acestui fenomen bazat pe literatura de specialitate, precum și modul în care aceasta se poate transforma dintr-un obiect al demersului științific în obiect al psihoterapiei sunt câteva din obiectivele atinse pe tot parcursul acestei lucrări.
Cuprins: Sexualitatea umană: Repere istorice; Hormonii sexuali și comportamentul sexual; Sistemul nervos și comportamentul sexual; Răspunsul sexual. Adicția umană versus dependența de sex: Definiția conceptului de dependență; Aspecte clinice și diagnostic; Elemente ale istoricului familial; Elemente distinctive ale dependenței de sex; Criterii pentru dependența de substanță; Substratul neurobiologic al dependenței; Rolul prolactinei în sațietatea sexuală; Adicția sexuală și ADHD; Definiția compulsivității. Relația dintre dependență și compulsivitate; Diverse aspecte ale adicției sexuale; Dependența de pornografie. Intervenții terapeutice: Terapia de grup ; Terapia de cuplu/familie; Terapia farmacologică. România, încă rușinea Europei. Ce riscuri implică lipsa educației sexuale în școli: Prostituție, sarcini nedorite la adolescente, agresiuni sexuale, violuri; Cum recunoaștem un pedofil? Soluțiile? Ce pot face părinții? Reacția comunității; Eficiența instituțiilor; Introducerea educației sexuale obligatorii în școli; Tratamentul pedofililor; Iubire pasională și dorință sexuală.
Lucrarea semnalează nevoia imediată de cercetare psiho-sociologică pe eşantion naţional în dome-niul sexualităţii, cercetări necesare corpului profesional şi în vederea consilierii, cu temei în cercetare, a factori-lor de decizie social-politică, tema tocmai fiind în dez-batere largă, pornind de la iniţiative legislative. Adicţia sexuală este un obiect încă deliberat în mediul asociaţiilor profesionale, unele care definesc con-duitele profesionale. Este de luat în considerare faptul că în România am avut-şi continuăm să avem-, difi-cultăţi în abordarea publică, extraprofesională, a proble-mei sexualităţii umane. Dominant este modelul eticist, concomitent existând o reală liberalizare a comporta-mentului sexual, dar fără a exista ghidajul adecvat care să permită comprehensiunea realităţii şi importanţa bunei integrări a sexualităţii în persoană, în fiecare etapă a constituirii sale, şi în buna structurare a interpersonali-tăţii şi raporturilor sociale, în acord cu modelul social în edificare, situaţie care comportă risc personal şi social. Comunităţile profesionale au nevoie de o mai atentă aplecare asupra problematicii, în acord cu progresul şti-inţific în discipline de vârf-cum este psihoneurofizio-logia-, asupra cărora autorul insistă. Autorul face parte din generaţia tânără de psihologi-cu formaţie de specialitate în ţară şi în străinătate, în mod special în spaţiul anglo-saxon-, spaţiu care exce-lează în cercetările ample din teren, începând din seco-lul XX şi până în prezent. Cartea constituie un plus de deschidere a domeniului şi are valoare de informare exactă asupra problemei adicţiei sexuale, utilă specialiş-tilor în demersul de psihodiagnoză diferenţială şi terapie.
The research group Morphophysiology and Biochemistry of Spermatozoa at
the Autonomous Metropolitan University (Iztapalapa Unit, UAM-I) as well
as the members of the Animal Reproduction Research Laboratory (LIRA) at
the Autonomous University of Oaxaca Benito Juárez began the Statewide
Reproduction Seminars in 2010, aiming to open a space in which the students
from both groups could show their research advances and providing a forum of
critic thought that allowed them to express freely, so as to raise questions from
the most basic level and gain firm knowledge from there on. This forum has grown
year after year, adding workshops that allow the students to standardize the
techniques they use in the lab, and to make their first incursions as handlers. The
workshops have tackled a wide range of practical field subjects, from artificial
insemination and the transfer of embryos in sheep and goats, to the evaluation
and freezing of semen at the lab.
The seminars have also involved the participation of members from the
research group Ecophysiology of Vertebrate Reproduction and the academic body
of Fertilization of Mammals, both from UAM-I, of Dr. Ávalos from the Autonomous
Metropolitan University (Xochimilco Unit), and of Dr. Arturo Gómez, from the
Autonomous University of the State of Mexico; and in 2017, the signing of an
agreement of academic collaboration between the research group Biotechnology
Applied to the Veterinary (UABJO), the Laboratory of Morphophysiology and
Biochemistry of the Spermatozoon (UAM-I), the Consortium of Spermatozoon
Physiology of the Biotechnology Institute (UNAM), the Biology Laboratory of the
Reproduction of the Faculty of Biological Sciences at the Autonomous University
of Puebla, and the Biology of Animal Reproduction Postgraduate Institute at the
UAM-I.
For most people, the spermatozoon is just “the other cell participating
in reproduction”; for us it’s a unique cell, with fascinating characteristics that
captures our attention and keeps us eternally amazed. So, we hope this book will
allow the reader to consider some of the contributions made on this subject from
Mexico, aiming to further what we know about this cell.
Presents the work of some groups in Mexico, which will be dedicated to the study of sperm.
The Coolidge effect is the renewal of sexual behavior after the presentation of a novel sexual partner and possibly occurs as the result of habituation and dishabituation processes. This re-motivation to copulate is well studied in males and is commonly related to sexual satiety, which involves several neurobiological changes in steroid receptors and their mRNA expression in the CNS. On the other hand, there are few reports studying sexual novelty in females and have been limited to behavioral aspects. Here we report that the levels of rat proceptive behavior, a sign of sexual motivation, declines after 4 h of continuous mating, particularly in females that were unable to regulate the time of mating. Such reduction was not accompanied by changes in lordosis, suggesting that they were not due to the vanishing of the endocrine optimal milieu necessary for the expression of both components of sexual behavior in the female rat. These and previous data support important differences between sexual behavior in both sexes that would result in natural divergences in the Coolidge effect expression. We here also review some reports in humans showing peculiarities between the pattern of habituation and dishabituation in women and men. This is a growing research field that needs emphasis in female's subjects.
The androgen receptor (AR) is generally considered an autoregulated protein. However, studies in brain have produced mixed results regarding sex differences, which should be present given the higher endogenous levels of androgens in males, and the effects of gonadectomy, which presumably should lead to a loss of AR. Resolving these issues is a necessary step in developing a model of AR regulation in the central nervous system and, more broadly, in determining how regulation of this receptor may mediate neural target tissue responsiveness to androgen. To further investigate these issues, the distribution, density, and regulation of neural AR were compared among male and female mice that were intact, gonadectomized, or gonadectomized and given testosterone propionate (TP) through immunocytochemical and Western blot analyses. Four brain areas that have been linked to the regulation of male-typical behavior were evaluated: bed nucleus of the stria terminalis, posterior aspect, medial preoptic area, and dorsal and ventral aspects of the lateral septum. In the immunocytochemical study, integrated particle density, which reflects the average intensity of AR staining, was assessed among the six groups 24 h after surgery using PG-21, a peptide-based AR antiserum. Major findings included regional differences in the intensity of immunostaining; a robust sexual dimorphism in each region, with males exhibiting more intense staining than females; a loss of AR in both sexes after gonadectomy, with more dramatic changes evident in males; and significant up-regulation of AR in response to TP that was equivalent in both sexes. The Western blot analyses of AR in limbic system extracts prepared from the six groups showed a pattern of differences that mirrored the immunocytochemical results, indicating that PG-21 recognized both liganded and unliganded AR. In addition, a dose-response study, in which gonadectomized males and females were administered from 25-1000 microg TP, demonstrated a significant linear trend in up-regulation of AR in both males and females, with no sexual dimorphism in the response to hormone treatment. These results demonstrate that the regulation of AR in both male and female neural tissue is comparable and that the critical determinant of AR expression is the presence or absence of androgen.
Twelve male rats were left with receptive females and allowed to copulate and ejaculate until they reached a criterion of “sexual exhaustion” They were then retested after 1, 3, 6 and 15 days of sexual inactivity. Following these observations males were tested once each day or once every other day and allowed to achieve a single ejaculation.
In the course of a period of unlimited access to the receptive female males usually need approximately 10 intromissions to produce the initial ejaculation, but successive ejaculations are produced by fewer and fewer intromissions. The time to recover from the effects of an ejaculation increases progressively as exhaustion is approached.
Very few animals copulate when tested 24 hours after sexual exhaustion. Considerably more recovery is evident in tests conducted after a 3-day rest, but it is not complete and rats are not capable of achieving as many ejaculations as they tend to achieve after longer periods of inactivity. As measured by ejaculation-frequency, the curve of sexual recovery is negatively accelerated and probably reaches asymptote after 7 to 10 days of rest.
Various other measures in addition to ejaculation-frequency support this conclusion. Males allowed to ejaculate once each day or every other day are somewhat less responsive than fully rested animals, but do not show any progressive loss in sexual excitability or capacity.
A working hypothesis is proposed to explain most of the findings. It postulates the existence of an Arousal Mechanism which is distinct from a Copulatory Mechanism. The ways in which these hypothetical mechanisms are affected by sexual performance and sexual rest arc discussed.
The present study reports for the first time the distribution of androgen receptor immunoreactivity (AR-ir) in the human hypothalamus of ten human subjects (five men and five women) ranging in age between 20 years and 39 years using the antibody PG21. Prolonged postmortem delay (72:00 hours) or fixation time (100 days) did not influence the AR-ir. In men, intense nuclear AR-ir was found in neurons of the horizontal limb of the diagonal band of Broca, in neurons of the lateromamillary nucleus (LMN), and in the medial mamillary nucleus (MMN). An intermediate nuclear staining was found in the diagonal band of Broca, sexually dimorphic nucleus of the preoptic area, paraventricular nucleus, suprachiasmatic nucleus, ventromedial nucleus, and infundibular nucleus, whereas weaker labeling was found in the bed nucleus of the stria terminalis, medial preoptic area, dorsal and ventral zones of the periventricular nucleus, supraoptic nucleus, and nucleus basalis of Meynert. In most brain areas, women revealed less staining than men. In the LMN and the MMN, a strong sex difference was found. Cytoplasmic labeling was observed in neurons of both sexes, although women showed a higher variability in the intensity of such staining. However, no sex differences in AR-ir were observed in the bed nucleus of the stria terminalis, the nucleus basalis of Meynert, or the islands of Calleja. Species differences and similarities of the AR-ir distribution are discussed. The present results suggest the participation of androgens in the regulation of various hypothalamic processes that are sexually dimorphic. J. Comp. Neurol. 425:422–435, 2000. © 2000 Wiley-Liss, Inc.
In the adult male rat, androgen and estrogen synergize in the regulation of male reproductive behaviors. To explore some of the molecular mechanisms underlying this synergism we examined the distribution and hormonal regulation of androgen receptor (AR) and estrogen receptor (ER) mRNAs in the medial preoptic area (MPOA) and bed nucleus of the stria terminalis (BST) of the adult male rat. Using in situ hybridization, AR and ER mRNAs were found to be distributed in overlapping but unique patterns. The highest density of AR mRNA was found in the central part of the medial preoptic n. and the principal n. of the BST. Gonadectomy (GDX) of adult male rats caused an increase in hybridization density in both brain areas after 4 days followed by a decrease after 2 months. In contrast, ER mRNA was increased following GDX and remained high regardless of length of time. Treatment of adult GDX'd males with dihydrotestosterone (DHT) reversed the effects of GDX on AR mRNA at both the short and long-term castrate but had no effect on ER mRNA in both the MPOA and BST. Estrogen treatment increased AR mRNA in the long-term castrate only and decreased ER mRNA in both long- and short-term castrates. Immunocytochemical detection of AR revealed a similar distribution to AR mRNA; however, AR immunoreactivity was reduced in the MPOA and BST after both short- and long-term GDX. In vitro [3H]DHT binding in cytosols of the preoptic area showed appreciable binding but there was no effect of length of time following GDX. These data show that the pattern of regulation of AR mRNA is unique to this receptor type and does not follow the pattern of regulation of the ER mRNA. Furthermore, although the distribution of AR mRNA and AR protein coincide within the MPOA, changes in mRNA levels as a result of castration of hormone treatment do not result in corresponding changes in binding. This mismatch between mRNA and binding suggests a complex regulation of AR beyond simply changes in transcription.
This study was conducted to determine whether there is a increase in responsiveness to the activating effects of testosterone on male reproductive behavior during puberty in male golden hamsters and whether responsiveness to behavioral actions of testosterone is correlated with the ability of testosterone to upregulate brain androgen receptor immunoreactivity (AR-ir). Sexually naive male hamsters were castrated at 21 or 42 days of age and implanted subcutaneously with a pellet containing 0, 2.5, or 5 mg of testosterone. One week later, males were given a 10-min mating test with a receptive female. Animals were euthanized 1 hr after the behavioral test, and blood samples and brains were collected. Plasma testosterone levels were equivalent in prepubertal and adult males that had been administered the same dose of testosterone. However, adult males exhibited more mounts, intromissions, and ejaculations than prepubertal males, demonstrating that postpubertal males are more responsive than prepubertal males to the effects of testosterone on sexual behavior. In both age groups, testosterone increased the number of AR-ir cells per unit area in several brain regions involved in male sexual behavior, including the medial preoptic nucleus (MPN), medial amygdala, posteromedial bed nucleus of the stria terminalis, and magnocellular preoptic nucleus (MPNmag). Surprisingly, testosterone increased AR-ir in the latter three regions to a greater extent in prepubertal males than in adults. Thus, prepubertal males are more responsive to the effects of testosterone on AR-ir in these regions. In a separate experiment, a pubertal increase in the number of AR-ir cells per unit area was found in both the MPN and MPNmag of intact male hamsters. These results indicate that a testosterone-dependent increase in brain AR during puberty may be necessary, but is not sufficient, to induce an increase in behavioral responsiveness to testosterone.
Two studies were designed to document neuronal colocalization of androgen receptor immunoreactivity and mating-induced Fos immunoreactivity (AR-ir, Fos-ir) in brain of male rats and to examine the extent to which limbic and midbrain neurons that project to the preoptic area are androgen sensitive and activated by mating. Brains from male rats, killed 1 h after ejaculating with receptive females, were examined for Fos-ir and AR-ir and compared with those from control rats not given access to females. PG21 anti-AR and anti-c-fos primary antibodies were visualized by fluorescence microscopy using cyanine-conjugated and fluorescein-conjugated secondary antibodies. In mated males (Expt. 1), Fos-ir and AR-ir were colocalized in neurons of the medial preoptic nucleus (MPN), the dorsal medial amygdala (dMEA), the central tegmental field (CTF), the bed nucleus of the stria terminalis, the anterior hypothalamus, the lateral hypothalamus, and the ventral premamillary nucleus. In Expt. 2, male rats received a unilateral injection of the retrograde tracer FluoroGold (FG) in the preoptic area and four days later were killed after ejaculating with receptive females. Brains were subsequently examined for FG transport, Fos-ir and AR-ir. Fluorogold-containing neurons were present in dMEA and CTF as well as in other hypothalamic and limbic regions known to project to the MPN. In dMEA and CTF, nuclear colocalization of AR-ir and mating-induced Fos-ir was present in a proportion of FG-containing neurons. Sexually relevant information may be carried through the brain by an interconnected network of hormone-sensitive neurons.