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Norbert Sachser - One of the best experts on this subject based on the ideXlab platform.
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effects of sex and time of day on metabolism and excretion of corticosterone in urine and feces of mice
General and Comparative Endocrinology, 2003Co-Authors: Chadi Touma, Norbert Sachser, Erich Mostl, Rupert PalmeAbstract:Non-invasive techniques to monitor stress hormones in small animals like mice offer several advantages and are highly demanded in laboratory as well as in field research. Since knowledge about the species-specific metabolism and excretion of glucocorticoids is essential to develop such a technique, we conducted radiometabolism studies in mice (Mus musculus f. domesticus, strain C57BL/6J). Each mouse was injected intraperitoneally with 740 kBq of 3H-labelled corticosterone and all voided urine and fecal samples were collected for five days. In a first experiment 16 animals (eight of each sex) received the injection at 9 a.m., while eight mice (four of each sex) were injected at 9 p.m. in a second experiment. In both experiments radioactive metabolites were recovered predominantly in the feces, although males excreted significantly higher proportions via the feces (about 73%) than females (about 53%). Peak radioactivity in the urine was detected within about 2h after injection, while in the feces peak concentrations were observed later (depending on the time of injection: about 10h postinjection in experiment 1 and about 4h postinjection in experiment 2, thus proving an effect of the time of day). The number and relative abundance of fecal [3H]corticosterone metabolites was determined by high performance liquid chromatography (HPLC). The HPLC separations revealed that corticosterone was extensively metabolized mainly to more polar substances. Regarding the types of metabolites formed, significant differences were found between males and females, but not between the experiments. Additionally, the immunoreactivity of these metabolites was assessed by screening the HPLC fractions with four enzyme immunoassays (EIA). However, only a newly established EIA for 5alpha-pregnane-3beta,11beta,21-triol-20-one (measuring corticosterone metabolites with a 5alpha-3beta,11beta-diol structure) detected several peaks of radioactive metabolites with high intensity in both sexes, while the other EIAs showed only minor immunoreactivity. Thus, our study for the first time provides substantial information about metabolism and excretion of corticosterone in urine and feces of mice and is the first demonstrating a significant impact of the animals' sex and the time of day. Based on these data it should be possible to monitor adrenocortical activity non-invasively in this species by measuring fecal corticosterone metabolites with the newly developed EIA. Since mice are extensively used in research world-wide, this could open new perspectives in various fields from ecology to Behavioral Endocrinology.
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the Behavioral Endocrinology of domestication a comparison between the domestic guinea pig cavia apereaf porcellus and its wild ancestor the cavy cavia aperea
Hormones and Behavior, 1999Co-Authors: Christine Kunzl, Norbert SachserAbstract:Abstract In this study spontaneous behavior and endocrine parameters were compared between the domestic guinea pig ( Cavia aperea f. porcellus ) and its wild ancestor, the cavy ( Cavia aperea ), to elucidate the process of domestication in this species. In 120 h of observation time the behavior of five groups of wild and seven groups of domestic guinea pigs, each consisting of one adult male and two adult females, was analyzed quantitatively. To assess the activities of the pituitary–adrenocortical (PAC), the pituitary–gonadal (PG), and the sympathetic–adrenomedullary (SAM) systems, serum cortisol, testosterone, epinephrine, and norepinephrine concentrations, as well as adrenal tyrosine hydroxylase activities, were determined in males of both forms. The following significant differences between wild cavies and domestic guinea pigs were found: the domesticated animals displayed less aggressive but more sociopositive and more male courtship behavior than their wild ancestors. In addition, they were distinctly less attentive to their physical environment than the wild cavies. The basal activity of the SAM system, as well as the reactivity of the SAM and the PAC systems, was distinctly reduced in the domesticated animals. In contrast, the basal activity of the PAC system did not differ between both forms. The activity of the PG system was significantly higher in males of the domestic guinea pig than in male wild cavies. Thus, in guinea pigs the process of domestication has led to typical Behavioral traits—reduced aggressiveness, increased social tolerance—which have also been found in comparisons between wild and domestic forms of other species. The decreased reactivity of the organism's stress axes can be regarded as a physiological mechanism which helps domesticated animals to adjust to man-made housing conditions.
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the Behavioral Endocrinology of domestication a comparison between the domestic guinea pig cavia aperea f porcellus and its wild ancestor the cavy cavia aperea
Hormones and Behavior, 1999Co-Authors: Christine Kunzl, Norbert SachserAbstract:In this study spontaneous behavior and endocrine parameters were compared between the domestic guinea pig (Cavia aperea f. porcellus) and its wild ancestor, the cavy (Cavia aperea), to elucidate the process of domestication in this species. In 120 h of observation time the behavior of five groups of wild and seven groups of domestic guinea pigs, each consisting of one adult male and two adult females, was analyzed quantitatively. To assess the activities of the pituitary-adrenocortical (PAC), the pituitary-gonadal (PG), and the sympathetic-adrenomedullary (SAM) systems, serum cortisol, testosterone, epinephrine, and norepinephrine concentrations, as well as adrenal tyrosine hydroxylase activities, were determined in males of both forms. The following significant differences between wild cavies and domestic guinea pigs were found: the domesticated animals displayed less aggressive but more sociopositive and more male courtship behavior than their wild ancestors. In addition, they were distinctly less attentive to their physical environment than the wild cavies. The basal activity of the SAM system, as well as the reactivity of the SAM and the PAC systems, was distinctly reduced in the domesticated animals. In contrast, the basal activity of the PAC system did not differ between both forms. The activity of the PG system was significantly higher in males of the domestic guinea pig than in male wild cavies. Thus, in guinea pigs the process of domestication has led to typical Behavioral traits-reduced aggressiveness, increased social tolerance-which have also been found in comparisons between wild and domestic forms of other species. The decreased reactivity of the organism's stress axes can be regarded as a physiological mechanism which helps domesticated animals to adjust to man-made housing conditions.
Steven J. Stanton - One of the best experts on this subject based on the ideXlab platform.
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The role of testosterone and estrogen in consumer behavior and social & economic decision making: A review
Hormones and behavior, 2016Co-Authors: Steven J. StantonAbstract:A contribution to a special issue on Hormones and Human Competition.This manuscript reviews the current literature on the actions of the steroid hormones testosterone and estradiol in shaping humans' behavior within two applied contexts, specifically consumer behavior and decision making (both social and economic). The theoretical argument put forth is that steroids shape these everyday behaviors and choices in service to being more competitive in achieving long-term goals related to resource acquisition, mating success, and social dominance. In addition, a discussion of the increased research focus on the role of steroids in other applied business domains will highlight the relevant applications of basic science discoveries in Behavioral Endocrinology.
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Seasonal variation of salivary testosterone in men, normally cycling women, and women using hormonal contraceptives.
Physiology & behavior, 2011Co-Authors: Steven J. Stanton, O'dhaniel A. Mullette-gillman, Scott A. HuettelAbstract:Humans' endogenous testosterone concentrations vary over a number of temporal scales, with little known about variation longer than monthly cycles. Past studies of seasonal or circannual variation have principally used male participants and have produced inconsistent results. Thus, little is known about how testosterone concentrations fluctuate throughout the year, whether such variation differs between men and women, and whether there are influences of hormonal contraceptive use. The present study collected saliva samples from a large sample (N=718) of men and women, each collected at one time point within a relatively uniform distribution over a full calendar year. Both men and normally-cycling women displayed seasonal variation in salivary testosterone concentrations, such that testosterone concentrations are maximal in the fall and minimal in the summer. Notably, normally-cycling women had testosterone concentrations that were over 100% greater at their maximum in fall compared to their minimum in summer. Women using hormonal contraceptives not only had consistently lower endogenous testosterone concentrations, but also showed a flatter seasonal testosterone profile. The implications for studies of psychology and human Behavioral Endocrinology are discussed.
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The essential implications of gender in human Behavioral Endocrinology studies.
Frontiers in behavioral neuroscience, 2011Co-Authors: Steven J. StantonAbstract:Carney et al. (2010) recently published a study in which they examined the effect of assuming “high- and low-power” body postures on changes in testosterone levels in men and women. To do so, they randomly assigned participants to two groups (high-power and low-power), and then placed them in two successive 1-min poses appropriate for their group. They reported that “high-power” poses produced testosterone increases in participants and “low-power” poses produced testosterone decrements, while collapsing over gender in their analyses. This study tested an important hypothesis regarding the effects of dominance posturing on endocrine changes that may be critical precursors to dominance competition, in which dominance posturing could lead to pre-competition changes in testosterone that influence the impending dominance competition (Mazur, 1985; Salvador et al., 2003; Gleason et al., 2009; Edwards and Kurlander, 2010). While Carney et al. (2010) asked an important research question, there are a number of methodological and analytical factors regarding gender and testosterone that must be considered in greater detail before their data can be fully understood and used to motivate future research.
Christine Kunzl - One of the best experts on this subject based on the ideXlab platform.
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the Behavioral Endocrinology of domestication a comparison between the domestic guinea pig cavia apereaf porcellus and its wild ancestor the cavy cavia aperea
Hormones and Behavior, 1999Co-Authors: Christine Kunzl, Norbert SachserAbstract:Abstract In this study spontaneous behavior and endocrine parameters were compared between the domestic guinea pig ( Cavia aperea f. porcellus ) and its wild ancestor, the cavy ( Cavia aperea ), to elucidate the process of domestication in this species. In 120 h of observation time the behavior of five groups of wild and seven groups of domestic guinea pigs, each consisting of one adult male and two adult females, was analyzed quantitatively. To assess the activities of the pituitary–adrenocortical (PAC), the pituitary–gonadal (PG), and the sympathetic–adrenomedullary (SAM) systems, serum cortisol, testosterone, epinephrine, and norepinephrine concentrations, as well as adrenal tyrosine hydroxylase activities, were determined in males of both forms. The following significant differences between wild cavies and domestic guinea pigs were found: the domesticated animals displayed less aggressive but more sociopositive and more male courtship behavior than their wild ancestors. In addition, they were distinctly less attentive to their physical environment than the wild cavies. The basal activity of the SAM system, as well as the reactivity of the SAM and the PAC systems, was distinctly reduced in the domesticated animals. In contrast, the basal activity of the PAC system did not differ between both forms. The activity of the PG system was significantly higher in males of the domestic guinea pig than in male wild cavies. Thus, in guinea pigs the process of domestication has led to typical Behavioral traits—reduced aggressiveness, increased social tolerance—which have also been found in comparisons between wild and domestic forms of other species. The decreased reactivity of the organism's stress axes can be regarded as a physiological mechanism which helps domesticated animals to adjust to man-made housing conditions.
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the Behavioral Endocrinology of domestication a comparison between the domestic guinea pig cavia aperea f porcellus and its wild ancestor the cavy cavia aperea
Hormones and Behavior, 1999Co-Authors: Christine Kunzl, Norbert SachserAbstract:In this study spontaneous behavior and endocrine parameters were compared between the domestic guinea pig (Cavia aperea f. porcellus) and its wild ancestor, the cavy (Cavia aperea), to elucidate the process of domestication in this species. In 120 h of observation time the behavior of five groups of wild and seven groups of domestic guinea pigs, each consisting of one adult male and two adult females, was analyzed quantitatively. To assess the activities of the pituitary-adrenocortical (PAC), the pituitary-gonadal (PG), and the sympathetic-adrenomedullary (SAM) systems, serum cortisol, testosterone, epinephrine, and norepinephrine concentrations, as well as adrenal tyrosine hydroxylase activities, were determined in males of both forms. The following significant differences between wild cavies and domestic guinea pigs were found: the domesticated animals displayed less aggressive but more sociopositive and more male courtship behavior than their wild ancestors. In addition, they were distinctly less attentive to their physical environment than the wild cavies. The basal activity of the SAM system, as well as the reactivity of the SAM and the PAC systems, was distinctly reduced in the domesticated animals. In contrast, the basal activity of the PAC system did not differ between both forms. The activity of the PG system was significantly higher in males of the domestic guinea pig than in male wild cavies. Thus, in guinea pigs the process of domestication has led to typical Behavioral traits-reduced aggressiveness, increased social tolerance-which have also been found in comparisons between wild and domestic forms of other species. The decreased reactivity of the organism's stress axes can be regarded as a physiological mechanism which helps domesticated animals to adjust to man-made housing conditions.
Patricia L. Whitten - One of the best experts on this subject based on the ideXlab platform.
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RESEARCH ARTICLE Dominance Rank and Fecal Testosterone Levels in Adult Male Chimpanzees (Pan troglodytes schweinfurthii )a t Ngogo, Kibale National Park, Uganda
2004Co-Authors: Michael P. Muehlenbein, David P. Watts, Patricia L. WhittenAbstract:n In an attempt to describe hormone-behavior interactions in a sample of wild male chimpanzees, we quantified testosterone in 67 fecal samples obtained from 22 adult male chimpanzees at Ngogo, Kibale National Park, Uganda. A mixed-model methodology that controlled for age-class identified a significant positive association between testosterone levels and dominance rank. The results are consistent with those reported from a separate, smaller chimpanzee community in the same population in a study that analyzed testosterone levels in urine (Muller & Wrangham, 2004). As in that earlier study, our results held during a period of social stability, which is not consistent with predictions of the ''challenge hypothesis.'' We concur with Muller and Wrangham (2004) that the challenge hypothesis requires modification to explain the chimpanzee data, because fission-fusion sociality in chimpanzees makes challenges unpredictable. We also discuss the utility of fecal samples and a mixed- model statistical method for Behavioral Endocrinology studies. Am. J. Primatol. 64:71-82, 2004. r 2004 Wiley-Liss, Inc.
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Dominance rank and fecal testosterone levels in adult male chimpanzees (Pan troglodytes schweinfurthii) at Ngogo, Kibale National Park, Uganda.
American journal of primatology, 2004Co-Authors: Michael P. Muehlenbein, David P. Watts, Patricia L. WhittenAbstract:In an attempt to describe hormone–behavior interactions in a sample of wild male chimpanzees, we quantified testosterone in 67 fecal samples obtained from 22 adult male chimpanzees at Ngogo, Kibale National Park, Uganda. A mixed-model methodology that controlled for age-class identified a significant positive association between testosterone levels and dominance rank. The results are consistent with those reported from a separate, smaller chimpanzee community in the same population in a study that analyzed testosterone levels in urine [Muller & Wrangham, 2004]. As in that earlier study, our results held during a period of social stability, which is not consistent with predictions of the “challenge hypothesis.” We concur with Muller and Wrangham [2004] that the challenge hypothesis requires modification to explain the chimpanzee data, because fission-fusion sociality in chimpanzees makes challenges unpredictable. We also discuss the utility of fecal samples and a mixed-model statistical method for Behavioral Endocrinology studies. Am. J. Primatol. 64:71–82, 2004. © 2004 Wiley-Liss, Inc.
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The Interaction of Hormones with Ecological Factors in Male Budongo Forest Chimpanzees
Developments in Primatology: Progress and Prospects, 1Co-Authors: Sally B. Seraphin, Patricia L. Whitten, Vernon ReynoldsAbstract:Behavioral endocrine studies have increasingly become a powerful tool for elucidating the ways in which specific hormones influence the expression of certain types of behavior. For instance, recent decades of research have implicated androgens in aggression, glucocorticoids in social dominance, gonadal steroids in courtship, and neuropeptides in social affiliation. However, no investigation of the Behavioral Endocrinology of wild animals is adequate without consideration of nonsocial and physiological-ecological, or ecophysiological, factors that may shape hormone secretions. While Behavioral endocrine studies typically focus on the interaction between hormones and an organism's social environment and
Susana Q. Lima - One of the best experts on this subject based on the ideXlab platform.
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No evidence for prolactin's involvement in the post-ejaculatory refractory period.
Communications biology, 2021Co-Authors: Susana Valente, Tiago Marques, Susana Q. LimaAbstract:In many species, ejaculation is followed by a state of decreased sexual activity, the post-ejaculatory refractory period. Several lines of evidence have suggested prolactin, a pituitary hormone released around the time of ejaculation in humans and other animals, to be a decisive player in the establishment of the refractory period. However, data supporting this hypothesis is controversial. We took advantage of two different strains of house mouse, a wild derived and a classical laboratory strain that differ substantially in their sexual performance, to investigate prolactin's involvement in sexual activity and the refractory period. First, we show that there is prolactin release during sexual behavior in male mice. Second, using a pharmacological approach, we show that acute manipulations of prolactin levels, either mimicking the natural release during sexual behavior or inhibiting its occurrence, do not affect sexual activity or shorten the refractory period, respectively. Therefore, we show compelling evidence refuting the idea that prolactin released during copulation is involved in the establishment of the refractory period, a long-standing hypothesis in the field of Behavioral Endocrinology.
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No evidence for prolactin's involvement in the post-ejaculatory refractory period
2020Co-Authors: Susana Valente, Tiago Marques, Susana Q. LimaAbstract:In many species, ejaculation is followed by a state of decreased sexual motivation, the post-ejaculatory refractory period. Several lines of evidence have suggested prolactin, a pituitary hormone released around the time of ejaculation in humans and other animals, to be a decisive player in the establishment of the refractory period. However, data supporting this hypothesis is controversial. We took advantage of two different strains of house mouse, a wild derived and a classical laboratory strain, that differ substantially in their sexual behavior, to investigate prolactin9s involvement in sexual motivation and the refractory period. First, we show that there is prolactin release during sexual behavior in male mice. Second, using a pharmacological approach, we show that acute manipulations of prolactin levels, either mimicking the natural release during sexual behavior or inhibiting its occurrence, do not affect sexual motivation or shorten the refractory period, respectively. Therefore, we show compelling evidence refuting the idea that prolactin released during copulation is involved in the establishment of the refractory period, a long-standing hypothesis in the field of Behavioral Endocrinology.