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Morozova MV, Boldyreva LV, Borisova MA, Kozhevnikova EN. Investigating social communication in mice: A two-intruders test approach. J Neurosci Res 2024; 102:e25365. [PMID: 39031484 DOI: 10.1002/jnr.25365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 06/04/2024] [Accepted: 06/16/2024] [Indexed: 07/22/2024]
Abstract
Understanding the complex dynamics of social communication behaviors, such as exploration, communication, courtship, mating, and aggression in animal models, is crucial to reveal key neural and hormonal mechanisms underlying these behaviors. The two-intruders test is designed to investigate residents' behavior toward both male and female intruders within the home cage of the test male. During this test imitating natural conditions, several aspects of social interaction were investigated: Exploration, courtship, mating, and aggressive behavior. As mating and aggression involve overlapping neural circuits, the behavioral setup testing both behaviors is best at reflecting their competitive nature. Our findings demonstrate that resident male mice exhibit strong preference to communicate with a female intruder, which correlates with baseline testosterone levels of test males. Relevant female preference in the two-intruders test was also found in BALB/c males. Behavioral breakdown revealed the anogenital sniffing as a key behavioral feature that discriminates resident male behavior toward intruders of different sex. Furthermore, resident male interaction with female intruder was accompanied by neuronal activation in the ventromedial hypothalamus. We demonstrate that odor recognition underlies preference toward females in male residents, as experimental anosmia reduced communication with a female intruder. We conclude the two-intruders test setup to be a useful tool to study the neurological basis of social communication in animal models, which provides detailed analysis of various aspects of the laboratory animals' social behavior in the most natural conditions.
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Affiliation(s)
- Maryana V Morozova
- Scientific-Research Institute of Neurosciences and Medicine, Novosibirsk, Russia
| | - Lidiya V Boldyreva
- Scientific-Research Institute of Neurosciences and Medicine, Novosibirsk, Russia
| | - Maria A Borisova
- The Federal Research Center Institute of Cytology and Genetics of the Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
| | - Elena N Kozhevnikova
- Scientific-Research Institute of Neurosciences and Medicine, Novosibirsk, Russia
- Novosibirsk State Agrarian University, Novosibirsk, Russia
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2
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Hernández A, Hoffman K, Reyes R, Fernández-Guasti A. Multiparity favors same-sex partner preference in male rats. Behav Brain Res 2024; 461:114842. [PMID: 38160811 DOI: 10.1016/j.bbr.2023.114842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 12/27/2023] [Accepted: 12/28/2023] [Indexed: 01/03/2024]
Abstract
Same-sex partner preference is present in many mammals, including rodents. Several possible causal factors have been proposed for the establishment of this preference. The Fraternal Birth Order effect refers to the observation that older brothers increase the probability of homosexuality in men, but no experiment has analyzed this possibility. In this study, partner preference (tested in a three compartments box) and female and male sexual behavior (studied in a cylindrical arena) were evaluated in young male rats (3 months) born to multiparous mothers that had 4-6 previous gestations and around 12 months of age. Control groups were young male rats born to primiparous young (4 months) or aged (12 months) mothers. In the partner preference test, the males born to multiparous dams spent less time interacting with the receptive female and more time interacting with the sexually active male, and a 39% exhibited same-sex partner preference. This high percentage seems related to multiparity of their mothers and not to maternal age, because the males born to primiparous aged females (12 months) showed a similar low proportion of same-sex partner preference than the males born to young (4 months) primiparous females (4%). In the sexual behavior tests, no male born of a multiparous dam and with same-sex preference ejaculated and 54% displayed proceptivity and lordosis. Present results suggest that the fraternal birth order effect may occur also in rats.
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Affiliation(s)
- Alejandra Hernández
- Departamento de Farmacobiología, Centro de Investigación y de Estudios Avanzados del IPN, Unidad Coapa, CDMX, Mexico
| | - Kurt Hoffman
- Centro de Investigación en Reproducción Animal, Cinvestav-UAT, Tlaxcala, Mexico
| | - Rebeca Reyes
- Departamento de Farmacobiología, Centro de Investigación y de Estudios Avanzados del IPN, Unidad Coapa, CDMX, Mexico
| | - Alonso Fernández-Guasti
- Departamento de Farmacobiología, Centro de Investigación y de Estudios Avanzados del IPN, Unidad Coapa, CDMX, Mexico.
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3
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Raymond M, Crochet PA. Carving Non-Proximal Explanations for Same-Sex Sexual Orientation. ARCHIVES OF SEXUAL BEHAVIOR 2023; 52:3007-3012. [PMID: 36469147 DOI: 10.1007/s10508-022-02497-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 11/19/2022] [Accepted: 11/21/2022] [Indexed: 06/17/2023]
Affiliation(s)
- Michel Raymond
- CNRS, EPHE, IRD, Institut des Sciences de l'Evolution, Univ Montpellier, Place E. Bataillon, 34095, Montpellier Cedex 05, France.
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4
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Phillips-Farfán BV, Quintanar BG, Reyes R, Fernández-Guasti A. Distribution of estrogen receptors alpha and beta in the brain of male rats with same-sex preference. Physiol Behav 2023; 268:114237. [PMID: 37192686 DOI: 10.1016/j.physbeh.2023.114237] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 04/24/2023] [Accepted: 05/12/2023] [Indexed: 05/18/2023]
Abstract
Two distinct estrogen receptors (ERs) exist, ERα and ERβ. Both receptors participate in the sexual differentiation of the rat brain and likely participate in the regulation of adult sexual orientation (i.e. partner preference). This last idea was investigated herein by examining males treated with the aromatase inhibitor, letrozole, administered prenatally (0.56 μg/kg G10-22). This treatment usually provokes same-sex preference in 1-2 males per litter. Vehicle-treated males (with female preference) and females in spontaneous proestrus (with male preference) were included as controls. ERα and ERβ expression was analyzed by immunohistochemistry in brain areas known to control masculine sexual behavior and partner preference, like the medial preoptic area (MPOA), bed nucleus of the stria terminalis (BNST), medial amygdala (MeA) and ventromedial hypothalamic nucleus (VMH), as well as other brain regions suspected to participate in these processes. In addition, serum levels of estradiol were determined in all male groups. Letrozole-treated male rats that preferred sexually experienced males (LPM) showed over-expressed ERα in the hippocampal cornu Ammonis (CA 1, 3, 4) and dentate gyrus. The LPM group showed up-regulated ERβ expression in the CA2 and reticular thalamic nucleus. The levels of estradiol did not differ between the groups. The higher expression of ERs in these males was different than their expression in females, with male sex-preference. This suggests that males with same-sex preference showed a unique brain, this sui generis steroid receptor expression probably participates in the biological underpinnings of sexual preference.
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Affiliation(s)
| | | | - Rebeca Reyes
- Departament of Pharmacobiology, Cinvestav, Unidad Coapa
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5
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Pazhoohi F, Garza R, Kingstone A. Lordosis Posture (Arching the Back) Indicates Sexual Receptivity in Women. ADAPTIVE HUMAN BEHAVIOR AND PHYSIOLOGY 2023. [DOI: 10.1007/s40750-023-00212-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/14/2023]
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6
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Tasos E. To What Extent are Prenatal Androgens Involved in the Development of Male Homosexuality in Humans? JOURNAL OF HOMOSEXUALITY 2022; 69:1928-1963. [PMID: 34080960 DOI: 10.1080/00918369.2021.1933792] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Endocrine variations, including possibly reduced exposure to androgens, may contribute to the development of male homosexuality, with animal models demonstrating same-sex mate preference with altered exposure during prenatal or early postnatal development. As similar studies in humans are impossible, indirect physical and cognitive measures of androgen exposure are used. Some studies suggest that physical measures affected by prenatal androgens, including the index-to-ring finger ratio, growth indices, and facial structure, are more "feminine" in gay men. Gay men also exhibit significant childhood gender non-conformity and a "feminized" anatomical and functional brain pattern in sexual arousal, as well as domains such as language, visuospatial skills and hemispheric relationships. However, many of these results are equivocal and may be confounded by other factors. Research has also been hampered by inconsistencies in the reporting of sexual orientation and the potentially unrepresentative populations of gay men studied, while additional complexities pertaining to gender conformity and sexual role may also influence results.
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Affiliation(s)
- Emmanouil Tasos
- School of Clinical Medicine, University of Cambridge, Cambridge, UK
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He F, Yan B, Tian Z, Wang B, Cheng X, Wang Z, Yu B. Clomiphene citrate treatment during perinatal development alters adult partner preference, mating behaviour and androgen receptor and vasopressin in the male mandarin vole Microtus mandarinus. Eur J Neurosci 2022; 56:4766-4787. [PMID: 35993282 DOI: 10.1111/ejn.15793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 07/27/2022] [Accepted: 08/03/2022] [Indexed: 11/29/2022]
Abstract
During development, many aspects of behaviour, including partner preferences and sexual behaviour, are "organized" by neural aromatization of androgen and oestrogen. This study aimed to analyse these processes in the mandarin vole (Microtus mandarinus); this is a novel mammalian model exhibiting strong monogamous pair bonds. Male pups were treated daily with a sesame oil only (MC) or the oestrogen receptor blocker-clomiphene citrate sesame oil mixture (MT) from prenatal day 14 to postnatal day 10. Female pups were treated daily with sesame oil only (FC). Partner preferences, sexual behaviour, and the expression of androgen receptor (AR) and arginine vasopressin (AVP) were examined when animals were 3 months old. The MT and FC groups exhibited male-directed partner preferences and feminized behaviour. AR-immunoreactive neurons (AR-IRs) in the medial preoptic area (mPOA), bed nucleus of stria terminalis (BNST), and medial amygdaloid nucleus (MeA) were reduced in MT males compared to MC males, and there was no significant difference in the number of AR-IRs between MT males and FC females. AVP-immunoreactive neurons (AVP-IRs) in the paraventricular nucleus (PVN) and supraoptic nucleus (SON) were reduced in MT males compared to MC males, and there were no significant differences in the number of AVP-IRs between MT males and FC females. The results indicate a significant role of hormone signalling in the development of male mate preference in the novel monogamous mammal model.
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Affiliation(s)
- Fengqin He
- College of Biology and Environmental Sciences, Xi'an University, Xi'an Key Laboratory of Natural Product Development and Anticancer Innovative Drug Research in Qinling, Xi'an, Shaanxi, China
| | - Bingjie Yan
- College of Biology and Environmental Sciences, Xi'an University, Xi'an Key Laboratory of Natural Product Development and Anticancer Innovative Drug Research in Qinling, Xi'an, Shaanxi, China
| | - Zhen Tian
- College of Biology and Environmental Sciences, Xi'an University, Xi'an Key Laboratory of Natural Product Development and Anticancer Innovative Drug Research in Qinling, Xi'an, Shaanxi, China
| | - Bo Wang
- College of Biology and Environmental Sciences, Xi'an University, Xi'an Key Laboratory of Natural Product Development and Anticancer Innovative Drug Research in Qinling, Xi'an, Shaanxi, China
| | - Xiaoxia Cheng
- College of Biology and Environmental Sciences, Xi'an University, Xi'an Key Laboratory of Natural Product Development and Anticancer Innovative Drug Research in Qinling, Xi'an, Shaanxi, China
| | - Zijian Wang
- College of Biology and Environmental Sciences, Xi'an University, Xi'an Key Laboratory of Natural Product Development and Anticancer Innovative Drug Research in Qinling, Xi'an, Shaanxi, China
| | - Bing Yu
- College of Biology and Environmental Sciences, Xi'an University, Xi'an Key Laboratory of Natural Product Development and Anticancer Innovative Drug Research in Qinling, Xi'an, Shaanxi, China
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Abstract
Previous research has shown that women may use self-enhancement strategies to compete with one other. Lumbar curvature in women is considered to enhance a woman′s attractiveness, potentially due to its role in bipedal fetal load and sexual receptiveness. The current study investigated the role of lumbar curvature on women’s perceptions of sexual receptiveness as well as its role in women’s intrasexual competitiveness. Study 1 (N = 138) tested and confirmed that women’s intrasexual competition influences their perception of sexual receptivity of women as a function of lordosis posture depicted in a standing posture. Study 2 (N = 69) replicated these results and extended them to other postures, namely, the quadruped and supine positions. Study 3 (N = 106), using a two-alternative forced-choice task, revealed that other women perceive relatively larger arched-back postures as more threatening to their relationship and frequently as being more attractive. Collectively, this work suggests that women consider a lordotic posture in other women as a signal of sexual receptivity and perceive it as a threat to their relationship. This research provides robust support for the sexually receptivity hypothesis of lumbar curvature, questioning the alternative morphological vertebral wedging hypothesis.
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Li H, Fernández-Guasti A, Xu Y, Swaab D. Retracted: Sexual orientation, neuropsychiatric disorders and the neurotransmitters involved. Neurosci Biobehav Rev 2021; 131:479-488. [PMID: 34597715 DOI: 10.1016/j.neubiorev.2021.09.048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 08/17/2021] [Accepted: 09/26/2021] [Indexed: 11/26/2022]
Abstract
This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor in Chief of Neuroscience and Biobehavioral Reviews after concerns were raised with respect to the phrasing of comparisons drawn between humans and animal models. These comparisons were deemed unsupportable, and thus in the best interests of publication standards the Editor has concluded it is necessary to retract the paper. The authors disagree with the reason for the retraction.
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Affiliation(s)
- Haimei Li
- Department of Psychiatry, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310003, PR China; Department of Neuropsychiatric Disorders, Netherlands Institute for Neuroscience, Amsterdam, 1105 BA, the Netherlands
| | | | - Yi Xu
- Department of Psychiatry, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310003, PR China; The Key Laboratory of Mental Disorder Management in Zhejiang Province, Hangzhou, 310003, PR China; Zhejiang Engineering Center for Mathematical Mental Health, Hangzhou, 310003, PR China; Brain Research Institute of Zhejiang University, Hangzhou, 31003, PR China.
| | - Dick Swaab
- Department of Neuropsychiatric Disorders, Netherlands Institute for Neuroscience, Amsterdam, 1105 BA, the Netherlands.
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10
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Ulker N, Yardimci A, Coban E, Ozcan M, Canpolat S. Chronic irisin exposure decreases sexual incentive motivation in female rats. Physiol Behav 2021; 232:113341. [PMID: 33508315 DOI: 10.1016/j.physbeh.2021.113341] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 01/20/2021] [Accepted: 01/25/2021] [Indexed: 11/20/2022]
Abstract
Irisin is a novel myokine/adipokine that is released into the circulation in response to types of exercise and increases energy expenditure. Disorders in the endocrine system related to reproduction, which occur due to the chronic or excessive exercise, cause a decrease in women's sexual desire. However, the role of irisin hormone on sexual desire in women has not been elucidated. We hypothesized that chronic irisin exposure would decrease sexual incentive motivation for male partners by affecting the endocrine system in female rats. We tested this by quantifying and comparing of both sexual incentive motivation and active investigation for sexual partner, and also changes in the serum hormone levels in chronically irisin-treated female rats. As a result, chronic irisin exposure decreased the time spent near the male rat, male preference ratio, and male investigation preference ratio. Furthermore, serum testosterone and progesterone levels significantly decreased and estradiol levels increased while kisspeptin-1 levels were not changed by chronic irisin exposure in female rats. These data indicate that chronic irisin exposure may cause low sexual incentive motivation for opposite-sex partners in female rats via changes in reproductive hormones. The results suggest that irisin hormone may play a role in decreased sexual desire due to long-term exercise in women.
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Affiliation(s)
- Nazife Ulker
- Department of Physiology, Faculty of Medicine, Firat University, Elazig, Turkey.
| | - Ahmet Yardimci
- Department of Physiology, Faculty of Medicine, Firat University, Elazig, Turkey
| | - Eda Coban
- Department of Physiology, Faculty of Medicine, Firat University, Elazig, Turkey
| | - Mete Ozcan
- Department of Biophysics, Faculty of Medicine, Firat University, Elazig, Turkey
| | - Sinan Canpolat
- Department of Physiology, Faculty of Medicine, Firat University, Elazig, Turkey
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11
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Oginni OA, Jern P, Rijsdijk FV. Mental Health Disparities Mediating Increased Risky Sexual Behavior in Sexual Minorities: A Twin Approach. ARCHIVES OF SEXUAL BEHAVIOR 2020; 49:2497-2510. [PMID: 32307644 PMCID: PMC7497451 DOI: 10.1007/s10508-020-01696-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 03/26/2020] [Accepted: 03/28/2020] [Indexed: 05/25/2023]
Abstract
Increased risky sexual behavior in sexual minorities relative to heterosexual individuals may be partly explained by mental health disparities, and both factors may be further jointly influenced by common genetic and environmental factors. However, these relationships have not been previously investigated. The objectives of the present study were to investigate mental health disparities as a mediator of the relationship between sexual orientation and risky sexual behavior, controlling for genetic and environmental effects in this relationship and testing for sex differences. Participants included 5814 twins from a Finnish twin cohort. Specified latent factors included sexual orientation, mental health indicators, and risky sexual behavior. Twin models were fitted to the factor structure of the data whereby a Cholesky decomposition on the factors was compared to a mediation submodel using OpenMx. Sex differences were tested in the final model. Phenotypically, mental health disparities partially mediated the relationship between sexual orientation and increased risky sexual behavior, with comparable effects in males and females. However, while this indirect route from sexual orientation to risky sexual behavior mainly contained transmitted genetic effects in males, there was a significant proportion of transmitted shared environmental effects in females. This is the first study to demonstrate that the mediation relationships between sexual orientation, mental health disparities, and risky sexual behavior are not confounded by genetic and environmental factors. The significant sex differences need to be recognized in future research and intervention design to improve sexual health in sexual minorities.
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Affiliation(s)
- Olakunle Ayokunmi Oginni
- The Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London, Denmark Hill, London, SE5 8AF, UK.
| | - Patrick Jern
- Department of Psychology, Åbo Akademi University, Åbo, Finland
| | - Frühling Vesta Rijsdijk
- The Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London, Denmark Hill, London, SE5 8AF, UK
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12
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Hernández A, Olvera-Hernández S, Fernández-Guasti A. Lack of interaction between prenatal stress and prenatal letrozole to induce same-sex preference in male rats. Physiol Behav 2020; 224:113042. [PMID: 32619527 DOI: 10.1016/j.physbeh.2020.113042] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 06/12/2020] [Accepted: 06/28/2020] [Indexed: 12/29/2022]
Abstract
Same-sex partner preference between males has been observed in all species in which this behavior has been studied. Disruption of brain estradiol synthesis during development has been proposed as one of the biological causes underlying this behavior in some mammals. In support of this possibility, perinatal administration of aromatase inhibitors (such as letrozole) to male rat pups, induces around half of them to have same-sex preference and female sexual behavior in adulthood. Another putative factor that modifies sex preference is prenatal stress. Several stress protocols, applied to the pregnant dam, cause some of the adult male progeny to have an increased male preference, a decreased preference for the female, and lordosis behavior. Interestingly, these effects of stress might be mediated by its inhibitory action on brain aromatase. The aim of the present study was to analyze a possible interaction between these two factors in male rats. Pregnant dams were exposed to one of the four treatments across gestation days 10-22 (G10-G22): 1) vehicle-treated non-stressed controls; 2) letrozole (0.56 µg/kg); 3) 30 min immobilization stress); 4) both letrozole and stress combined. The male offspring were tested in adulthood for partner preference in a three-chambered arena, where we also recorded the masculine and feminine sexual behaviors. One week later males were tested for masculine and feminine sexual behavior in cylindrical arenas where they interacted for 30 min with a receptive female and thereafter with a sexually active male for another 30 min. Letrozole, stress and their combination resulted in same-sex preference in 40, 31 and 50% of males, respectively, compared to 5% in the control group. In the sexual behavior tests, prenatal stress reduced the percentage of males displaying intromissions and ejaculation (impaired masculinization), while letrozole mainly increased lordosis (impaired defeminization). The males prenatally submitted to stress and treated with letrozole presented these behavioral features but did not differ from both treatments given independently. The results indicate that the changes induced by stress or the aromatase inhibition produced by letrozole only accounts for a shift in partner preference in around half of the males and that there was no interaction between these two factors.
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Affiliation(s)
- Alejandra Hernández
- Pharmacobiology Department. Center of Research and Advanced Studies of IPN (CINVESTAV), México
| | - Sandra Olvera-Hernández
- Medical and Psychology School, Autonomous University of Baja California, Tijuana, B.C., México
| | - Alonso Fernández-Guasti
- Pharmacobiology Department. Center of Research and Advanced Studies of IPN (CINVESTAV), México..
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13
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Roselli CE. Programmed for Preference: The Biology of Same-Sex Attraction in Rams. Neurosci Biobehav Rev 2020; 114:12-15. [PMID: 32311371 DOI: 10.1016/j.neubiorev.2020.03.032] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 03/30/2020] [Accepted: 03/31/2020] [Indexed: 01/09/2023]
Abstract
The sheep is a valuable model to test whether hormone mechanisms that sexually differentiate the brain underlie the expression of sexual partner preferences because as many as 8% of rams prefer same-sex partners. This review presents an overview and update of the experimental evidence that supports this hypothesis. New evidence is presented that demonstrates a critical role for kisspeptin-GnRH signaling for regulating stable fetal testosterone levels necessary for masculinization of brain and behavior. Although these studies provide substantial support for the idea that prenatal hormones program sexual preferences, further experimentation is needed to establish causality.
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Affiliation(s)
- Charles E Roselli
- Department of Chemical Physiology & Biochemistry, Oregon Health & Science University, Portland, OR, 97239-3098, USA.
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14
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Daae E, Feragen KB, Waehre A, Nermoen I, Falhammar H. Sexual Orientation in Individuals With Congenital Adrenal Hyperplasia: A Systematic Review. Front Behav Neurosci 2020; 14:38. [PMID: 32231525 PMCID: PMC7082355 DOI: 10.3389/fnbeh.2020.00038] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Accepted: 02/21/2020] [Indexed: 12/12/2022] Open
Abstract
Congenital adrenal hyperplasia (CAH) is a genetic condition of the steroidogenic enzymes in the adrenal cortex normally leading to variable degrees of cortisol and aldosterone deficiency as well as androgen excess. Exposure to androgens prenatally might lead to ambiguous genitalia. The fetal brain develops in traditional male direction through a direct action of androgens on the developing nerve cells, or in the traditional female direction in the absence of androgens. This may indicate that sexual development, including sexual orientation, are programmed into our brain structures prenatally. The objective of this study was to perform a systematic review of the literature, investigating sexual orientation in individuals with CAH. The study also aimed at identifying which measures are used to define sexual orientation across studies. The review is based on articles identified through a comprehensive search of the OVIDMedline, PsycINFO, CINAHL, and Web of Science databases published up to May 2019. All peer-reviewed articles investigating sexual orientation in people with CAH were included. Quantitative, qualitative, and mixed methods were considered, as well as self-, parent-, and third-party reports, and no age or language restrictions were enforced on publications. The present review included 30 studies investigating sexual orientation in patients with CAH assigned female at birth (46, XX) (n = 927) or assigned male at birth (46, XY and 46, XX) (n = 274). Results indicate that assigned females at birth (46, XX) with CAH had a greater likelihood to not have an exclusively heterosexual orientation than females from the general population, whereas no assigned males at birth (46, XY or 46, XX) with CAH identified themselves as non-heterosexual. There was a wide diversity in measures used and a preference for unvalidated and self-constructed interviews. Hence, the results need to be interpreted with caution. Methodological weaknesses might have led to non-heterosexual orientation being overestimated or underestimated. The methodological challenges identified by this review should be further investigated in future studies.
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Affiliation(s)
| | | | | | - Ingrid Nermoen
- Oslo University, Oslo, Norway
- Akershus University Hospital, Lillestrøm, Norway
| | - Henrik Falhammar
- Karolinska Institute, Karolinska University Hospital, Stockholm, Sweden
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15
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Bogaert AF, Skorska MN. A short review of biological research on the development of sexual orientation. Horm Behav 2020; 119:104659. [PMID: 31911036 DOI: 10.1016/j.yhbeh.2019.104659] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2019] [Revised: 12/16/2019] [Accepted: 12/17/2019] [Indexed: 11/15/2022]
Abstract
We review research supporting biological mechanisms in the development of sexual orientation. This research includes studies on neural correlates, prenatal hormones and related physical/behavioral correlates, genetics, and the fraternal birth order effect (FBOE). These studies, taken together, have provided substantial support for biological influences underlying the development of sexual orientation, but questions remain unanswered, including how biological mechanisms may differ in contributing to men's and women's sexual orientation development.
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Affiliation(s)
- Anthony F Bogaert
- Department of Health Sciences, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, ON L2S 3A1, Canada; Department of Psychology, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, ON L2S 3A1, Canada.
| | - Malvina N Skorska
- Department of Psychology, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, ON L2S 3A1, Canada; Department of Psychology, University of Toronto Mississauga, 3359 Mississauga Road North, Mississauga, ON L5L 1C6, Canada.
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16
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Adkins-Regan E. Sexual and pairing partner preference in birds and other animals. Horm Behav 2020; 118:104646. [PMID: 31778718 DOI: 10.1016/j.yhbeh.2019.104646] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Accepted: 11/14/2019] [Indexed: 10/25/2022]
Abstract
Research on hormonal involvement in animals' preferences for mating or pairing with same- or other-sex partners has been among the topics featured in Hormones and Behavior over the years. In several species of non-pair-forming mammals, there is good evidence that the early sex steroid environment has an organizational effect on later sexual partner preference. Research with zebra finches, a pair-forming species, shows a likely early estrogenic organizational hormone effect on pairing partner preference, an effect that can also interact with the early social environment to determine adult pairing preference. Experiments with two amphibian and fish species suggest that activational hormone effects (effects of the hormone milieu in adulthood) may regulate sexual partner preference. As a complement to the research on hormonal involvement, a growing body of theoretical and empirical research addresses the possible adaptive functions of the same-sex sexual and pairing behavior observed in many wild animals. Such advances have important implications for conceptualizing neuroendocrine mechanisms of partner preferences.
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Affiliation(s)
- Elizabeth Adkins-Regan
- Department of Psychology and Department of Neurobiology and Behavior, Cornell University, Ithaca, NY 14853, USA.
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Wang Y, Wu H, Sun ZS. The biological basis of sexual orientation: How hormonal, genetic, and environmental factors influence to whom we are sexually attracted. Front Neuroendocrinol 2019; 55:100798. [PMID: 31593707 DOI: 10.1016/j.yfrne.2019.100798] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 09/29/2019] [Accepted: 10/03/2019] [Indexed: 12/11/2022]
Abstract
Humans develop relatively stable attractions to sexual partners during maturation and present a spectrum of sexual orientation from homosexuality to heterosexuality encompassing varying degrees of bisexuality, with some individuals also displaying asexuality. Sexual orientation represents a basic life phenomenon for humans. However, the molecular mechanisms underlying these diverse traits of sexual orientation remain highly controversial. In this review, we systematically discuss recent advancements in sexual orientation research, including those related to measurements and associated brain regions. Current findings regarding sexual orientation modulation by hormonal, genetic, maternal immune system, and environmental factors are summarized in both human and model systems. We also emphasize that future studies should recognize the differences between males and females and pay more attention to minor traits and the epigenetic regulation of sexual orientation. A comprehensive view of sexual orientation may promote our understanding of the biological basis of sex, and that of human reproduction, and evolution.
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Affiliation(s)
- Yan Wang
- Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing 100101, China
| | - Haoda Wu
- Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing 100101, China; Sino-Danish College, University of the Chinese Academy of Sciences, Beijing 100190, China
| | - Zhong Sheng Sun
- Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing 100101, China; Sino-Danish College, University of the Chinese Academy of Sciences, Beijing 100190, China; Institute of Genomic Medicine, Wenzhou Medical University, Wenzhou 325000, China.
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Gore AC, Krishnan K, Reilly MP. Endocrine-disrupting chemicals: Effects on neuroendocrine systems and the neurobiology of social behavior. Horm Behav 2019; 111:7-22. [PMID: 30476496 PMCID: PMC6527472 DOI: 10.1016/j.yhbeh.2018.11.006] [Citation(s) in RCA: 79] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 10/25/2018] [Accepted: 11/14/2018] [Indexed: 02/06/2023]
Abstract
A contribution to SBN/ICN special issue. Endocrine-disrupting chemicals (EDCs) are pervasive in the environment. They are found in plastics and plasticizers (bisphenol A (BPA) and phthalates), in industrial chemicals such as polychlorinated biphenyls (PCBs), and include some pesticides and fungicides such as vinclozolin. These chemicals act on hormone receptors and their downstream signaling pathways, and can interfere with hormone synthesis, metabolism, and actions. Because the developing brain is particularly sensitive to endogenous hormones, disruptions by EDCs can change neural circuits that form during periods of brain organization. Here, we review the evidence that EDCs affect developing hypothalamic neuroendocrine systems, and change behavioral outcomes in juvenile, adolescent, and adult life in exposed individuals, and even in their descendants. Our focus is on social, communicative and sociosexual behaviors, as how an individual behaves with a same- or opposite-sex conspecific determines that individual's ability to exist in a community, be selected as a mate, and reproduce successfully.
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Affiliation(s)
- Andrea C Gore
- Division of Pharmacology and Toxicology, The University of Texas at Austin, Austin, TX 78712, USA; Department of Psychology, The University of Texas at Austin, Austin, TX 78712, USA.
| | - Krittika Krishnan
- Department of Psychology, The University of Texas at Austin, Austin, TX 78712, USA
| | - Michael P Reilly
- Division of Pharmacology and Toxicology, The University of Texas at Austin, Austin, TX 78712, USA
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Olvera-Hernández S, Hernández A, Reyes R, Fernández-Guasti A. Establishment of partner preference in male rats: Effect of prenatal letrozole and sexual experience. Horm Behav 2019; 109:56-63. [PMID: 30769015 DOI: 10.1016/j.yhbeh.2019.02.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Revised: 02/05/2019] [Accepted: 02/10/2019] [Indexed: 01/07/2023]
Abstract
Repeated testing for masculine sexual behavior influences female sex preference in males. Males perinatally treated with aromatase inhibitors show male preference, but also copulate with the receptive female. Such copulation modifies sex preference most likely because of its rewarding properties. In this study, we intended to equal the incentive value of both stimuli -in the sex preference test- by using receptive females with vaginal occlusion. Vehicle and letrozole-treated (0.56 μg/kg, gestation days 10-21) males were repeatedly tested for sex preference at 40, 55, 70, 85 and 100 days of age. These ages were selected because males of 40 days are unable to copulate, while by 100 days of age almost all males show the complete repertoire of masculine sexual behavior. At 40 days of age, males of all groups fail to show sex preference and none of them was able to copulate. In controls of 100 days of age all males showed female-sex preference and all intromitted the female. A large proportion (44%) of vehicle-treated males that could not copulate the female showed male preference. Twenty to 30% of the prenatally letrozole treated males also had same-sex preference even if they could copulate; and most of them (67%) had a male preference when copulation was precluded. These data support the idea that copulation is crucial for developing a female preference in control animals. The results suggest that brain changes produced by estrogens along early development and stimuli coming from the partner are essential for shaping sex preference.
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Affiliation(s)
- Sandra Olvera-Hernández
- Departamento de Farmacobiología, Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional, México
| | - Alejandra Hernández
- Departamento de Farmacobiología, Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional, México
| | - Rebeca Reyes
- Departamento de Farmacobiología, Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional, México
| | - Alonso Fernández-Guasti
- Departamento de Farmacobiología, Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional, México.
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Hiyama G, Mizushima S, Matsuzaki M, Tobari Y, Choi JH, Ono T, Tsudzuki M, Makino S, Tamiya G, Tsukahara N, Sugita S, Sasanami T. Female Japanese quail visually differentiate testosterone-dependent male attractiveness for mating preferences. Sci Rep 2018; 8:10012. [PMID: 29968815 PMCID: PMC6030125 DOI: 10.1038/s41598-018-28368-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Accepted: 06/21/2018] [Indexed: 12/27/2022] Open
Abstract
Biased mating due to female preferences towards certain traits in males is a major mechanism driving sexual selection, and may constitute an important evolutionary force in organisms with sexual reproduction. In birds, although the role of male ornamentation, plumage coloration, genetic dissimilarity, and body size have on mate selection by females have been examined extensively, few studies have clarified exactly how these characteristics affect female mate preferences. Here, we show that testosterone (T)-dependent male attractiveness enhances female preference for males of a polygamous species, the Japanese quail. A significant positive correlation between female mating preference and circulating T in the male was observed. The cheek feathers of attractive males contained higher levels of melanin and were more brightly colored. The ability of females to distinguish attractive males from other males was negated when the light source was covered with a sharp cut filter (cutoff; < 640 nm). When females were maintained under short-day conditions, the expression of retinal red-sensitive opsin decreased dramatically and they became insensitive to male attractiveness. Our results showed that female preference in quail is strongly stimulated by male feather coloration in a T-dependent manner and that female birds develop a keen sense for this coloration due to upregulation of retinal red-sensitive opsin under breeding conditions.
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Affiliation(s)
- Gen Hiyama
- Department of Applied Biological Chemistry, Faculty of Agriculture, Shizuoka University, 836 Ohya, Shizuoka, Shizuoka, 422-8529, Japan
- Medical-Industrial Translational Research Center, Fukushima Medical University, 1 Hikarigaoka, Fukushima, 960-8031, Japan
| | - Shusei Mizushima
- Department of Biological Sciences, Faculty of Science, Hokkaido University, Kita 10 Nishi 8, Kita-ku, Sapporo, Hokkaido, 060-0810, Japan
| | - Mei Matsuzaki
- Department of Applied Biological Chemistry, Faculty of Agriculture, Shizuoka University, 836 Ohya, Shizuoka, Shizuoka, 422-8529, Japan
| | - Yasuko Tobari
- Laboratory of Animal Genetics and Breeding, School of Veterinary Medicine, Azabu University, Fuchinobe 1-17-71, Sagamihara, 252-5201, Japan
| | - Jae-Hoon Choi
- Department of Applied Biological Chemistry, Faculty of Agriculture, Shizuoka University, 836 Ohya, Shizuoka, Shizuoka, 422-8529, Japan
| | - Takashi Ono
- Laboratory of Animal Breeding and Genetics, Graduate School of Biosphere Science, Hiroshima University, Higashi-Hiroshima, 739-8528, Japan
| | - Masaoki Tsudzuki
- Laboratory of Animal Breeding and Genetics, Graduate School of Biosphere Science, Hiroshima University, Higashi-Hiroshima, 739-8528, Japan
| | - Satoshi Makino
- Tohoku Medical Megabank Organization, Tohoku University, 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8575, Japan
| | - Gen Tamiya
- Tohoku Medical Megabank Organization, Tohoku University, 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8575, Japan
- RIKEN Center for Advanced Intelligence Project, 1-4-1 Nihonbashi, Chuo-ku, Tokyo, 103-0027, Japan
| | - Naoki Tsukahara
- CrowLab Inc., Utsunomiya-ventures #3, Tochigi Prefecture Industrial Center, 3-1-4, Chuo, Utsunomiya-shi, Tochigi, 320-0806, Japan
| | - Shoei Sugita
- Faculty of Agriculture, Utsunomiya University, Utsunomiya, Tochigi, 321-8505, Japan
| | - Tomohiro Sasanami
- Department of Applied Biological Chemistry, Faculty of Agriculture, Shizuoka University, 836 Ohya, Shizuoka, Shizuoka, 422-8529, Japan.
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21
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Roselli CE. Neurobiology of gender identity and sexual orientation. J Neuroendocrinol 2018; 30:e12562. [PMID: 29211317 PMCID: PMC6677266 DOI: 10.1111/jne.12562] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 11/03/2017] [Accepted: 11/28/2017] [Indexed: 12/15/2022]
Abstract
Sexual identity and sexual orientation are independent components of a person's sexual identity. These dimensions are most often in harmony with each other and with an individual's genital sex, although not always. The present review discusses the relationship of sexual identity and sexual orientation to prenatal factors that act to shape the development of the brain and the expression of sexual behaviours in animals and humans. One major influence discussed relates to organisational effects that the early hormone environment exerts on both gender identity and sexual orientation. Evidence that gender identity and sexual orientation are masculinised by prenatal exposure to testosterone and feminised in it absence is drawn from basic research in animals, correlations of biometric indices of androgen exposure and studies of clinical conditions associated with disorders in sexual development. There are, however, important exceptions to this theory that have yet to be resolved. Family and twin studies indicate that genes play a role, although no specific candidate genes have been identified. Evidence that relates to the number of older brothers implicates maternal immune responses as a contributing factor for male sexual orientation. It remains speculative how these influences might relate to each other and interact with postnatal socialisation. Nonetheless, despite the many challenges to research in this area, existing empirical evidence makes it clear that there is a significant biological contribution to the development of an individual's sexual identity and sexual orientation.
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Affiliation(s)
- C E Roselli
- Department of Physiology & Pharmacology, Oregon Health & Science University, Portland, OR, USA
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22
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Reilly MP, Weeks CD, Crews D, Gore AC. Application of a novel social choice paradigm to assess effects of prenatal endocrine-disrupting chemical exposure in rats (Rattus norvegicus). ACTA ACUST UNITED AC 2018; 132:253-267. [PMID: 29683687 DOI: 10.1037/com0000103] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Endocrine-disrupting chemical (EDC) exposures during critical periods of gestation cause long-lasting behavioral effects, presumably by disturbing hormonal organization of the brain. Among such EDCs are polychlorinated biphenyls (PCBs), a class of industrial chemicals. PCB exposure in utero leads to alterations in mating behaviors and other sexually dimorphic social interactions in rats. Many of the previous studies on social behavior gave the experimental animal a single or binary choice. This study applied a more complex behavioral apparatus, an X-shaped Plexiglas apparatus (FourPlex), that enabled an experimental animal exposed to PCBs or a vehicle to distinguish and choose among 4 stimulus animals of the same or opposite sex, and of different hormonal status. We found that rats were able to differentiate among the stimuli in the FourPlex and showed the expected preference for an opposite sex, hormone-treated rat, particularly for behaviors conducted in proximity. Prenatal treatment caused subtle shifts in behavior toward stimulus rats in the FourPlex; more robust effects were seen for the sexual dimorphisms in behavior. Importantly, the results differ from our previous results of a simple binary choice model, showing that how an animal behaves in a more complex social paradigm does not predict the outcome in a simple choice model, and vice versa. (PsycINFO Database Record
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Affiliation(s)
- Michael P Reilly
- Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin
| | - Connor D Weeks
- College of Natural Sciences, The University of Texas at Austin
| | - David Crews
- Section of Integrative Biology, The University of Texas at Austin
| | - Andrea C Gore
- Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin
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Adekunbi DA, Li XF, Lass G, Shetty K, Adegoke OA, Yeo SH, Colledge WH, Lightman SL, O'Byrne KT. Kisspeptin neurones in the posterodorsal medial amygdala modulate sexual partner preference and anxiety in male mice. J Neuroendocrinol 2018; 30:e12572. [PMID: 29356147 PMCID: PMC5873280 DOI: 10.1111/jne.12572] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Revised: 01/05/2018] [Accepted: 01/16/2018] [Indexed: 01/27/2023]
Abstract
The posterodorsal medial amygdala (MePD) is a neural site in the limbic brain involved in regulating emotional and sexual behaviours. There is, however, limited information available on the specific neuronal cell type in the MePD functionally mediating these behaviours in rodents. The recent discovery of a significant kisspeptin neurone population in the MePD has raised interest in the possible role of kisspeptin and its cognate receptor in sexual behaviour. The present study therefore tested the hypothesis that the MePD kisspeptin neurone population is involved in regulating attraction towards opposite sex conspecifics, sexual behaviour, social interaction and the anxiety response by selectively stimulating these neurones using the novel pharmacosynthetic DREADDs (designer receptors exclusively activated by designer drugs) technique. Adult male Kiss-Cre mice received bilateral stereotaxic injections of a stimulatory DREADD viral construct (AAV-hSyn-DIO-hM3 D(Gq)-mCherry) targeted to the MePD, with subsequent activation by i.p. injection of clozapine-N-oxide (CNO). Socio-sexual behaviours were assessed in a counter-balanced fashion after i.p. injection of either saline or CNO (5 mg kg-1 ). Selective activation of MePD kisspeptin neurones by CNO significantly increased the time spent by male mice in investigating an oestrous female, as well as the duration of social interaction. Additionally, after CNO injection, the mice appeared less anxious, as indicated by a longer exploratory time in the open arms of the elevated plus maze. However, levels of copulatory behaviour were comparable between CNO and saline-treated controls. These data indicate that DREADD-induced activation of MePD kisspeptin neurones enhances both sexual partner preference in males and social interaction and also decreases anxiety, suggesting a key role played by MePD kisspeptin in sexual motivation and social behaviour.
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Affiliation(s)
- D. A. Adekunbi
- Division of Women's HealthFaculty of Life Sciences and MedicineKing's College LondonLondonUK
- Department of PhysiologyCollege of MedicineUniversity of LagosLagosNigeria
| | - X. F. Li
- Division of Women's HealthFaculty of Life Sciences and MedicineKing's College LondonLondonUK
| | - G. Lass
- Division of Women's HealthFaculty of Life Sciences and MedicineKing's College LondonLondonUK
| | - K. Shetty
- Division of Women's HealthFaculty of Life Sciences and MedicineKing's College LondonLondonUK
| | - O. A. Adegoke
- Department of PhysiologyCollege of MedicineUniversity of LagosLagosNigeria
| | - S. H. Yeo
- Reproductive Physiology GroupDepartment of Physiology, Development and NeuroscienceUniversity of CambridgeCambridgeUK
| | - W. H. Colledge
- Reproductive Physiology GroupDepartment of Physiology, Development and NeuroscienceUniversity of CambridgeCambridgeUK
| | - S. L. Lightman
- Henry Wellcome Laboratory for Integrative Neuroscience and EndocrinologyUniversity of BristolBristolUK
| | - K. T. O'Byrne
- Division of Women's HealthFaculty of Life Sciences and MedicineKing's College LondonLondonUK
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Pazhoohi F, Doyle JF, Macedo AF, Arantes J. Arching the Back (Lumbar Curvature) as a Female Sexual Proceptivity Signal: an Eye-Tracking Study. EVOLUTIONARY PSYCHOLOGICAL SCIENCE 2017. [DOI: 10.1007/s40806-017-0123-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Baum MJ, Bakker J. Reconsidering Prenatal Hormonal Influences on Human Sexual Orientation: Lessons from Animal Research. ARCHIVES OF SEXUAL BEHAVIOR 2017; 46:1601-1605. [PMID: 28474307 DOI: 10.1007/s10508-017-0994-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 04/22/2017] [Indexed: 06/07/2023]
Affiliation(s)
- Michael J Baum
- Department of Biology, Boston University, Boston, MA, 02215, USA.
| | - Julie Bakker
- GIGA Neurosciences, University of Liege, 4000, Liege, Belgium
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Burmeister SS, Rodriguez Moncalvo VG, Pfennig KS. Monoaminergic integration of diet and social signals in the brains of juvenile spadefoot toads. ACTA ACUST UNITED AC 2017; 220:3135-3141. [PMID: 28659306 DOI: 10.1242/jeb.159954] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2017] [Accepted: 06/21/2017] [Indexed: 01/19/2023]
Abstract
Social behavior often includes the production of species-specific signals (e.g. mating calls or visual displays) that evoke context-dependent behavioral responses from conspecifics. Monoamines are important neuromodulators that have been implicated in context-dependent social behavior, yet we know little about the development of monoaminergic systems and whether they mediate the effects of early life experiences on adult behavior. We examined the effects of diet and social signals on monoamines early in development in the plains spadefoot toad (Spea bombifrons), a species in which diet affects the developmental emergence of species recognition and body condition affects the expression of adult mating preferences. To do so, we manipulated the diet of juveniles for 6 weeks following metamorphosis and collected their brains 40 min following the presentation of either a conspecific or a heterospecific call. We measured levels of monoamines and their metabolites using high pressure liquid chromatography from tissue punches of the auditory midbrain (i.e. torus semicircularis), hypothalamus and preoptic area. We found that call type affected dopamine and noradrenaline signaling in the auditory midbrain and that diet affected dopamine and serotonin in the hypothalamus. In the preoptic area, we detected an interaction between diet and call type, indicating that diet modulates how the preoptic area integrates social information. Our results suggest that the responsiveness of monoamine systems varies across the brain and highlight preoptic dopamine and noradrenaline as candidates for mediating effects of early diet experience on later expression of social preferences.
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Affiliation(s)
- Sabrina S Burmeister
- Department of Biology, University of North Carolina, Chapel Hill, NC 27599, USA .,Curriculum in Neurobiology, University of North Carolina, Chapel Hill, NC 27599, USA
| | | | - Karin S Pfennig
- Department of Biology, University of North Carolina, Chapel Hill, NC 27599, USA
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Csaba G. The Present and Future of Human Sexuality: Impact of Faulty Perinatal Hormonal Imprinting. Sex Med Rev 2017; 5:163-169. [DOI: 10.1016/j.sxmr.2016.10.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Revised: 10/24/2016] [Accepted: 10/25/2016] [Indexed: 01/04/2023]
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Prenatal administration of letrozole reduces SDN and SCN volume and cell number independent of partner preference in the male rat. Physiol Behav 2017; 171:61-68. [PMID: 28057567 DOI: 10.1016/j.physbeh.2017.01.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 12/30/2016] [Accepted: 01/01/2017] [Indexed: 12/17/2022]
Abstract
During development, the exposure to testosterone, and its conversion to estradiol by an enzyme complex termed aromatase, appears to be essential in adult male rats for the expression of typical male sexual behavior and female-sex preference. Some hypothalamic areas are the supposed neural bases of sexual preference/orientation; for example, male-oriented rams have a reduced volume of the sexually dimorphic nucleus (oSDN), while in homosexual men this nucleus does not differ from that of heterosexual men. In contrast, homosexual men showed a larger number of vasopressinergic cells in the suprachiasmatic nucleus (SCN). Interestingly, male rats perinatally treated with an aromatase inhibitor, 1,4,6-androstatriene-3,17-dione (ATD), also showed bisexual preference and an increased number of vasopressinergic neurons in the SCN. However, this steroidal aromatase inhibitor has affinity for all three steroid receptors. Recently, we reported that the prenatal administration of the selective aromatase inhibitor, letrozole, produced a subpopulation of males with same-sex preference. The aim of this study was to compare the volume and number of cells of the SDN and SCN (the latter nucleus was immunohistochemically stained for vasopressin) between males treated with letrozole with same-sex preference, males treated with letrozole with female preference and control males with female preference. Results showed that all males prenatally treated with letrozole have a reduced volume and estimated cell number in the SDN and SCN, independent of their partner preference. These results indicate that the changes in these brain areas are not related to sexual preference, but rather to the effects of letrozole. The divergent results may be explained by species differences as well as by the critical windows during which the aromatase inhibitor was administered.
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30
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Mate-choice copying, social information processing, and the roles of oxytocin. Neurosci Biobehav Rev 2016; 72:232-242. [PMID: 27923732 DOI: 10.1016/j.neubiorev.2016.12.003] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Revised: 11/23/2016] [Accepted: 12/01/2016] [Indexed: 01/07/2023]
Abstract
Social and sexual behaviors, including that of mate choice, are dependent on social information. Mate choice can be modified by prior and ongoing social factors and experience. The mate choice decisions of one individual can be influenced by either the actual or potential mate choice of another female or male. Such non-independent mate choice, where individuals gain social information and socially learn about and recognizes potential mates by observing the choices of another female or male, has been termed "mate-choice copying". Here we first briefly review how, why, and under what circumstances individuals engage in mate-choice copying. Secondly, we review the neurobiological mechanisms underlying mate-choice copying. In particular, we consider the roles of the nonapeptide, oxytocin, in the processing of social information and the expression of mate-choice copying.
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Effects of neonatal treatment with two phytoestrogens on male rat sexual behavior and partner preference. Behav Pharmacol 2016; 27:570-8. [PMID: 27482864 DOI: 10.1097/fbp.0000000000000249] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The aim of this work was to compare the effect of neonatal treatment with the phytoestrogens coumestrol (COU) and genistein (GEN), administered in equimolecular doses, on the sexual behavior and partner preference of male rats. Four groups of male rats were injected daily from day 1 to 5 with 150 µg of GEN, an equivalent amount of COU, 1 µg of β-estradiol 3-benzoato (EB), or olive oil (VEH) (control). A fifth group remained intact. In the GEN group, intromission and ejaculation latencies decreased, whereas ejaculatory frequency increased. Contrasting results were observed in COU males. EB males could not ejaculate and their mount and intromission latencies increased significantly. To determine sexual-partner preferences, a multiple partner preference arena was used and two types of tests were performed, the first one without allowing contact test (CT) with the stimulus animals, followed by a CT. COU and GEN groups did not show preference for any stimulus animal, whereas the EB males preferred the expert male. When CT with the stimulus animals was allowed, GEN-males preferred the receptive female, unlike the COU and EB groups. It is concluded that neonatal treatment with COU and GEN induced opposite effects, the effects of COU being more estrogenic.
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Roselli CE, Meaker M, Stormshak F, Estill CT. Effects of Long-Term Flutamide Treatment During Development on Sexual Behaviour and Hormone Responsiveness in Rams. J Neuroendocrinol 2016; 28:10.1111/jne.12389. [PMID: 27005749 PMCID: PMC4882258 DOI: 10.1111/jne.12389] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Revised: 03/14/2016] [Accepted: 03/19/2016] [Indexed: 01/06/2023]
Abstract
Testosterone exposure during midgestation differentiates neural circuits controlling sex-specific behaviours and patterns of gonadotrophin secretion in male sheep. Testosterone acts through androgen receptors (AR) and/or after aromatisation to oestradiol and binding to oestrogen receptors. The present study assessed the role of AR activation in male sexual differentiation. We compared rams that were exposed to the AR antagonist flutamide (Flu) throughout the critical period (i.e. days 30-90 of gestation) to control rams and ewes that received no prenatal treatments. The external genitalia of all Flu rams were phenotypically female. Testes were positioned s.c. in the inguinal region of the abdomen, exhibited seasonally impaired androgen secretion and were azospermic. Flu rams displayed male-typical precopulatory and mounting behaviours but could not intromit or ejaculate because they lacked a penis. Flu rams exhibited greater mounting behaviour than control rams and, similar to controls, showed sexual partner preferences for oestrous ewes. Neither control, nor Flu rams responded to oestradiol treatments with displays of female-typical receptive behaviour or LH surge responses, whereas all control ewes responded as expected. The ovine sexually dimorphic nucleus in Flu rams was intermediate in volume between control rams and ewes and significantly different from both. These results indicate that prenatal anti-androgen exposure is not able to block male sexual differentiation in sheep and suggest that compensatory mechanisms intervene to maintain sufficient androgen stimulation during development.
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Affiliation(s)
- Charles E. Roselli
- Department of Physiology and Pharmacology, Oregon Health and Science University, Portland, OR 97239-3098
| | - Mary Meaker
- Department of Animal and Rangeland Sciences, Oregon State University, Corvallis, OR 97331-4501
| | - Fred Stormshak
- Department of Animal and Rangeland Sciences, Oregon State University, Corvallis, OR 97331-4501
| | - Charles T. Estill
- Department of Animal and Rangeland Sciences, Oregon State University, Corvallis, OR 97331-4501
- College of Veterinary Medicine, Oregon State University, Corvallis, OR 97331-4501
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Diamond LM, Rosky CJ. Scrutinizing Immutability: Research on Sexual Orientation and U.S. Legal Advocacy for Sexual Minorities. JOURNAL OF SEX RESEARCH 2016; 53:363-91. [PMID: 26986464 DOI: 10.1080/00224499.2016.1139665] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
We review scientific research and legal authorities to argue that the immutability of sexual orientation should no longer be invoked as a foundation for the rights of individuals with same-sex attractions and relationships (i.e., sexual minorities). On the basis of scientific research as well as U.S. legal rulings regarding lesbian, gay, and bisexual (LGB) rights, we make three claims: First, arguments based on the immutability of sexual orientation are unscientific, given what we now know from longitudinal, population-based studies of naturally occurring changes in the same-sex attractions of some individuals over time. Second, arguments based on the immutability of sexual orientation are unnecessary, in light of U.S. legal decisions in which courts have used grounds other than immutability to protect the rights of sexual minorities. Third, arguments about the immutability of sexual orientation are unjust, because they imply that same-sex attractions are inferior to other-sex attractions, and because they privilege sexual minorities who experience their sexuality as fixed over those who experience their sexuality as fluid. We conclude that the legal rights of individuals with same-sex attractions and relationships should not be framed as if they depend on a certain pattern of scientific findings regarding sexual orientation.
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Bailey JM, Vasey PL, Diamond LM, Breedlove SM, Vilain E, Epprecht M. Sexual Orientation, Controversy, and Science. Psychol Sci Public Interest 2016; 17:45-101. [DOI: 10.1177/1529100616637616] [Citation(s) in RCA: 316] [Impact Index Per Article: 39.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Summary Ongoing political controversies around the world exemplify a long-standing and widespread preoccupation with the acceptability of homosexuality. Nonheterosexual people have seen dramatic surges both in their rights and in positive public opinion in many Western countries. In contrast, in much of Africa, the Middle East, the Caribbean, Oceania, and parts of Asia, homosexual behavior remains illegal and severely punishable, with some countries retaining the death penalty for it. Political controversies about sexual orientation have often overlapped with scientific controversies. That is, participants on both sides of the sociopolitical debates have tended to believe that scientific findings—and scientific truths—about sexual orientation matter a great deal in making political decisions. The most contentious scientific issues have concerned the causes of sexual orientation—that is, why are some people heterosexual, others bisexual, and others homosexual? The actual relevance of these issues to social, political, and ethical decisions is often poorly justified, however.
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Affiliation(s)
| | | | | | | | - Eric Vilain
- Department of Human Genetics, University of California, Los Angeles
- Department of Pediatrics, University of California, Los Angeles
- Department of Urology, University of California, Los Angeles
- Joint International Unit on Epigenetics, Data, and Politics, Centre National de la Recherche Scientifique, Paris, France
| | - Marc Epprecht
- Department of History, Queen’s University
- Department of Global Development Studies, Queen’s University
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Bell MR, Thompson LM, Rodriguez K, Gore AC. Two-hit exposure to polychlorinated biphenyls at gestational and juvenile life stages: 1. Sexually dimorphic effects on social and anxiety-like behaviors. Horm Behav 2016; 78:168-77. [PMID: 26592453 PMCID: PMC4718783 DOI: 10.1016/j.yhbeh.2015.11.007] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Revised: 11/09/2015] [Accepted: 11/20/2015] [Indexed: 11/17/2022]
Abstract
Endocrine disrupting chemicals (EDCs) are widespread environmental contaminants that affect many neuroendocrine functions. The brain is particularly vulnerable to EDCs during critical periods of gestational development when gonadal hormones exert organizational effects on sexually dimorphic behaviors later in life. Peripubertal development is also a time of continued neural sensitivity to organizing effects of hormones, yet little is known about EDC actions at these times. We sought to determine effects of prenatal or juvenile exposures to a class of EDCs, polychlorinated biphenyls (PCBs) at human-relevant dosages on development, physiology, and social and anxiety-related behaviors later in life, and the consequences of a second juvenile "hit" following prenatal treatment. We exposed male and female Sprague-Dawley rats to PCBs (Aroclor 1221, 1mg/kg/day, ip injection) and/or vehicle during prenatal development (embryonic days 16, 18, 20), juvenile development (postnatal days 24, 26, 28), or both. These exposures had differential effects on behaviors in sex and age-dependent ways; while prenatal exposure had more effects than juvenile, juvenile exposure often modified or unmasked the effects of the first hit. Additionally, females exhibited altered social and anxiety behavior in adolescence, while males displayed small but significant changes in sociosexual preferences in adulthood. Thus, the brain continues to be sensitive to organizing effects of EDCs through juvenile development. As humans are exposed to EDCs throughout multiple periods in their life, these findings have implications for our understanding of EDC effects on physiology and behavior.
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Affiliation(s)
- Margaret R Bell
- Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, Austin, TX 78712, USA
| | - Lindsay M Thompson
- Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, Austin, TX 78712, USA
| | - Karla Rodriguez
- Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, Austin, TX 78712, USA; Franklin College, Franklin, IN 46131, USA
| | - Andrea C Gore
- Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, Austin, TX 78712, USA; Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX 78712, USA; Institute for Neuroscience, The University of Texas at Austin, Austin, TX 78712, USA.
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Bell MR, Hart BG, Gore AC. Two-hit exposure to polychlorinated biphenyls at gestational and juvenile life stages: 2. Sex-specific neuromolecular effects in the brain. Mol Cell Endocrinol 2016; 420:125-37. [PMID: 26620572 PMCID: PMC4703537 DOI: 10.1016/j.mce.2015.11.024] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Revised: 11/20/2015] [Accepted: 11/21/2015] [Indexed: 10/22/2022]
Abstract
Exposures to polychlorinated biphenyls (PCBs) during early development have long-lasting, sexually dimorphic consequences on adult brain and behavior. However, few studies have investigated their effects during juvenile development, a time when increases in pubertal hormones influence brain maturation. Here, male and female Sprague Dawley rats were exposed to PCBs (Aroclor 1221, 1 mg/kg/day) or vehicle prenatally, during juvenile development, or both, and their effects on serum hormone concentrations, gene expression, and DNA methylation were assessed in adulthood. Gene expression in male but not female brains was affected by 2-hits of PCBs, a result that paralleled behavioral effects of PCBs. Furthermore, the second hit often changed the effects of a first hit in complex ways. Thus, PCB exposures during critical fetal and juvenile developmental periods result in unique neuromolecular phenotypes, with males most vulnerable to the treatments.
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Affiliation(s)
- Margaret R Bell
- Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, Austin, TX 78712, USA
| | - Bethany G Hart
- Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, Austin, TX 78712, USA
| | - Andrea C Gore
- Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, Austin, TX 78712, USA; Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX 78712, USA; Institute for Neuroscience, The University of Texas at Austin, Austin, TX 78712, USA.
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Derouiche L, Keller M, Martini M, Duittoz AH, Pillon D. Developmental Exposure to Ethinylestradiol Affects Reproductive Physiology, the GnRH Neuroendocrine Network and Behaviors in Female Mouse. Front Neurosci 2015; 9:463. [PMID: 26696819 PMCID: PMC4673314 DOI: 10.3389/fnins.2015.00463] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 11/23/2015] [Indexed: 01/10/2023] Open
Abstract
During development, environmental estrogens are able to induce an estrogen mimetic action that may interfere with endocrine and neuroendocrine systems. The present study investigated the effects on the reproductive function in female mice following developmental exposure to pharmaceutical ethinylestradiol (EE2), the most widespread and potent synthetic steroid present in aquatic environments. EE2 was administrated in drinking water at environmentally relevant (ENVIR) or pharmacological (PHARMACO) doses [0.1 and 1 μg/kg (body weight)/day respectively], from embryonic day 10 until postnatal day 40. Our results show that both groups of EE2-exposed females had advanced vaginal opening and shorter estrus cycles, but a normal fertility rate compared to CONTROL females. The hypothalamic population of GnRH neurons was affected by EE2 exposure with a significant increase in the number of perikarya in the preoptic area of the PHARMACO group and a modification in their distribution in the ENVIR group, both associated with a marked decrease in GnRH fibers immunoreactivity in the median eminence. In EE2-exposed females, behavioral tests highlighted a disturbed maternal behavior, a higher lordosis response, a lack of discrimination between gonad-intact and castrated males in sexually experienced females, and an increased anxiety-related behavior. Altogether, these results put emphasis on the high sensitivity of sexually dimorphic behaviors and neuroendocrine circuits to disruptive effects of EDCs.
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Affiliation(s)
- Lyes Derouiche
- PRC, UMR 7247 INRA/CNRS/Université François-Rabelais de Tours/IFCE Nouzilly, France
| | - Matthieu Keller
- PRC, UMR 7247 INRA/CNRS/Université François-Rabelais de Tours/IFCE Nouzilly, France
| | - Mariangela Martini
- PRC, UMR 7247 INRA/CNRS/Université François-Rabelais de Tours/IFCE Nouzilly, France
| | - Anne H Duittoz
- PRC, UMR 7247 INRA/CNRS/Université François-Rabelais de Tours/IFCE Nouzilly, France
| | - Delphine Pillon
- PRC, UMR 7247 INRA/CNRS/Université François-Rabelais de Tours/IFCE Nouzilly, France
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Shi Q, Ishii H, Tanaka K, Sugahara Y, Takanishi A, Okabayashi S, Huang Q, Fukuda T. Behavior modulation of rats to a robotic rat in multi-rat interaction. BIOINSPIRATION & BIOMIMETICS 2015; 10:056011. [PMID: 26414400 DOI: 10.1088/1748-3190/10/5/056011] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
In this paper, we study the behavioral response of rats to a robotic rat during multi-rat interaction. Experiments are conducted in an open-field where a robotic rat called WR-5 is put together with three laboratory rats. WR-5 is following one rat (target), while avoiding the other two rats (outside observers) during interaction. The behavioral characteristics of each target rat is evaluated by scoring its locomotor activity and frequencies of performing rearing, body grooming and mounting actions. Additionally, the frequency of being mounted by other rats is also measured. Experimental results show that the target becomes more active after interaction. The rat species, with more active behavioral characteristics, is more susceptible to being adjusted by the robot. The increased time spent by the outside observers in the vicinity of the robot indicates that a biomimetic robot has the promise for modulating rat behavior even without direct interaction. Thus, this study provide a novel approach to shaping the sociality of animals living in groups.
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Affiliation(s)
- Qing Shi
- Intelligent Robotics Institute, School of Mechatronical Engineering, Beijing Institute of Technology, Beijing, 100081, People's Republic of China. Centre for Advanced Biomedical Sciences, TWInS, Waseda University, Tokyo,162-8480, Japan
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Prenatal letrozole produces a subpopulation of male rats with same-sex preference and arousal as well as female sexual behavior. Physiol Behav 2015; 139:403-11. [DOI: 10.1016/j.physbeh.2014.11.060] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Revised: 11/18/2014] [Accepted: 11/19/2014] [Indexed: 01/28/2023]
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40
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Shi Q, Ishii H, Kinoshita S, Takanishi A, Okabayashi S, Iida N, Kimura H, Shibata S. Modulation of rat behaviour by using a rat-like robot. BIOINSPIRATION & BIOMIMETICS 2013; 8:046002. [PMID: 24091776 DOI: 10.1088/1748-3182/8/4/046002] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
In this paper, we study the response of a rat to a rat-like robot capable of generating different types of behaviour (stressful, friendly, neutral). Experiments are conducted in an open-field where a rat-like robot called WR-4 is put together with live rats. The activity level of each rat subject is evaluated by scoring its locomotor activity and frequencies of performing rearing (rising up on its hind limbs) and body grooming (body cuddling and head curling) actions, whereas the degree of preference of that is indicated by the robot-rat distance and the frequency of contacting WR-4. The moving speed and behaviour of WR-4 are controlled in real-time based on the feedback from rat motion. The activity level and degree of preference of rats for each experimental condition are analysed and compared to understand the influence of robot behaviour. The results of this study show that the activity level and degree of preference of the rat decrease when exposed to a stressful robot, and increase when the robot exhibit friendly behaviour, suggesting that a rat-like robot can modulate rat behaviour in a controllable, predictable way.
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Affiliation(s)
- Qing Shi
- Intelligent Robotics Institute, School of Mechatronical Engineering, Beijing Institute of Technology, Beijing 100081, People's Republic of China. Waseda University, TWIns, 2-2, Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan
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41
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Variation in female mate choice and mating success is affected by sex ratio experienced during early life. Anim Behav 2013. [DOI: 10.1016/j.anbehav.2013.05.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Portillo W, Antonio-Cabrera E, Camacho FJ, Díaz NF, Paredes RG. Behavioral characterization of non-copulating male mice. Horm Behav 2013; 64:70-80. [PMID: 23673371 DOI: 10.1016/j.yhbeh.2013.05.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Revised: 04/30/2013] [Accepted: 05/02/2013] [Indexed: 11/26/2022]
Abstract
Non-copulating (NC) males are those animals that do not mate in spite of repeated testing with sexually receptive females. They have been observed in several species including rats and mice. The present experiment was designed to perform a detailed behavioral characterization of NC male mice. Thus, we evaluated their sexual incentive motivation for a sexually receptive female or a sexually active male, olfactory preference for volatile and non-volatile odors from females or males, and olfactory discrimination between female and male volatile odors and food related odors (milk versus vinegar). We compared the activity of the accessory olfactory system (AOS) in copulating (C) and NC males in response to estrous bedding using the induction of Fos-immunoreactivity (Fos-IR) as a measure of neuronal activation. We also determined if estradiol or dopamine treatment could induce sexual behavior in NC males. Finally, we compared the testis weight and the number of penile spines in C, NC, and gonadectomized males. In the sexual incentive motivation test C males spend significantly more time in the female incentive zone than in the male incentive zone. On the other hand, NC males spend the same amount of time in both incentive zones. In tests of olfactory preference, NC males spent less time investigating estrous odors than C males. As well, NC males discriminate urine from conspecifics but they spend less time smelling these odors than C males. In addition, no increase in Fos expression is observed in NC males when they are exposed to odors from estrous females. Our data also suggest that the deficits observed in NC males are not due to lower circulating levels of gonadal hormones, because estradiol supplementation does not induce sexual behavior in these animals, and their testis weight and the number of penile spines are normal. The results suggest that NC males are not sexually motivated by the receptive females and their odors.
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Affiliation(s)
- W Portillo
- Instituto de Neurobiología Universidad Nacional Autónoma de México, México.
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43
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Tomaszycki ML, Dzubur E. 17β-Hydroxysteroid dehydrogenase type IV, a Z-linked gene, is higher in females than in males in visual and auditory regions of developing zebra finches. Brain Res 2013; 1520:95-106. [PMID: 23692956 DOI: 10.1016/j.brainres.2013.05.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2012] [Revised: 05/08/2013] [Accepted: 05/10/2013] [Indexed: 11/16/2022]
Abstract
One of the most important decisions in a monogamous animal's life is the choice of a partner (partner preference), but the process by which this occurs remains poorly understood. The present study tests the hypothesis that hormones and genes play a role in sexual differentiation of partner preferences, as in the song system. We focused on a Z-linked gene, 17β-hydroxysteroid dehydrogenase type IV (HSD17B4), coding for a steroidogenic enzyme that converts estradiol (E2) into an inactive metabolite. HSD17B4 mRNA is expressed more in the song regions of males compared to females throughout development, suggesting that regulation of E2 is important for male-typical song development. Here, we focused on four regions associated with sexual partner preferences. Females had significantly higher levels of HSD17B4 mRNA in auditory (caudomedial nidopallium) and visual (hyperpallium apicale) regions than did males at day 25. HSD17B4 was expressed in the hippocampus and caudolateral nidopallium, but there were no sex differences. In a second experiment, animals of both sexes were treated with E2 and HSD17B4 and androgen receptor (AR) mRNA were measured, since masculinization of the song system is, in part, accomplished by AR. AR was low across the four regions and was not sexually differentiated. E2 treatments increased HSD17B4 mRNA in the auditory region of males, which is contrary to findings in the song system. Our research suggests that different behaviors may be guided by the same genes and hormones, but that the exact nature of the gene-hormone relationships may differ according to brain region and behavior.
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Choleris E, Clipperton-Allen AE, Phan A, Valsecchi P, Kavaliers M. Estrogenic involvement in social learning, social recognition and pathogen avoidance. Front Neuroendocrinol 2012; 33:140-59. [PMID: 22369749 DOI: 10.1016/j.yfrne.2012.02.001] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2011] [Revised: 02/13/2012] [Accepted: 02/14/2012] [Indexed: 12/25/2022]
Abstract
Sociality comes with specific cognitive skills that allow the proper processing of information about others (social recognition), as well as of information originating from others (social learning). Because sociality and social interactions can also facilitate the spread of infection among individuals the ability to recognize and avoid pathogen threat is also essential. We review here various studies primarily from the rodent literature supporting estrogenic involvement in the regulation of social recognition, social learning (socially acquired food preferences and mate choice copying) and the recognition and avoidance of infected and potentially infected individuals. We consider both genomic and rapid estrogenic effects involving estrogen receptors α and β, and G-protein coupled estrogen receptor 1, along with their interactions with neuropeptide systems in the processing of social stimuli and the regulation and expression of these various socially relevant behaviors.
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Affiliation(s)
- Elena Choleris
- Department of Psychology, University of Guelph, Guelph, Ontario, Canada N1G 2W1.
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Flinn MV, Ponzi D, Muehlenbein MP. Hormonal Mechanisms for Regulation of Aggression in Human Coalitions. HUMAN NATURE-AN INTERDISCIPLINARY BIOSOCIAL PERSPECTIVE 2012; 23:68-88. [DOI: 10.1007/s12110-012-9135-y] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Dela Cruz C, Pereira OCM. Prenatal testosterone supplementation alters puberty onset, aggressive behavior, and partner preference in adult male rats. J Physiol Sci 2012; 62:123-31. [PMID: 22234789 PMCID: PMC10718014 DOI: 10.1007/s12576-011-0190-7] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2011] [Accepted: 12/19/2011] [Indexed: 10/14/2022]
Abstract
The objective of this study was to investigate whether prenatal exposure to testosterone (T) could change the body weight (BW), anogenital distance (AGD), anogenital distance index (AGDI), puberty onset, social behavior, fertility, sexual behavior, sexual preference, and T level of male rats in adulthood. To test this hypothesis, pregnant rats received either 1 mg/animal of T propionate diluted in 0.1 ml peanut oil or 0.1 ml peanut oil, as control, on the 17th, 18th and 19th gestational days. No alterations in BW, AGD, AGDI, fertility, and sexual behavior were observed (p > 0.05). Delayed onset of puberty (p < 0.0001), increased aggressive behavior (p > 0.05), altered pattern of sexual preference (p < 0.05), and reduced T plasma level (p < 0.05) were observed for adult male rats exposed prenatally to T. In conclusion, the results showed that prenatal exposure to T was able to alter important aspects of sexual and social behavior although these animals were efficient at producing descendants. In this sense more studies should be carried to evaluated the real impact of this hormonal alteration on critical period of sexual differentiation on humans, because pregnant women exposed to hyperandrogenemia and then potentially exposing their unborn children to elevated androgen levels in the uterus can undergo alteration of normal levels of T during the sexual differentiation period, and, as a consequence, affect the reproductive and behavior patterns of their children in adulthood.
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Affiliation(s)
- Cynthia Dela Cruz
- Department of Physiology and Biophysics, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
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Jefferson WN, Patisaul HB, Williams CJ. Reproductive consequences of developmental phytoestrogen exposure. Reproduction 2012; 143:247-60. [PMID: 22223686 PMCID: PMC3443604 DOI: 10.1530/rep-11-0369] [Citation(s) in RCA: 127] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Phytoestrogens, estrogenic compounds derived from plants, are ubiquitous in human and animal diets. These chemicals are generally much less potent than estradiol but act via similar mechanisms. The most common source of phytoestrogen exposure to humans is soybean-derived foods that are rich in the isoflavones genistein and daidzein. These isoflavones are also found at relatively high levels in soy-based infant formulas. Phytoestrogens have been promoted as healthy alternatives to synthetic estrogens and are found in many dietary supplements. The aim of this review is to examine the evidence that phytoestrogen exposure, particularly in the developmentally sensitive periods of life, has consequences for future reproductive health.
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Affiliation(s)
- Wendy N. Jefferson
- Reproductive Medicine Group, Laboratory of Reproductive and Developmental Toxicology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Heather B. Patisaul
- Department of Biology, North Carolina State University, Raleigh NC 27695, USA
| | - Carmen J. Williams
- Reproductive Medicine Group, Laboratory of Reproductive and Developmental Toxicology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
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Ganter GK, Desilets JB, Davis-Knowlton JA, Panaitiu AE, Sweezy M, Sungail J, Tan LCH, Adams AM, Fisher EA, O'Brien JRM, Kincaid KM, Heinrich R. Drosophila female precopulatory behavior is modulated by ecdysteroids. JOURNAL OF INSECT PHYSIOLOGY 2012; 58:413-419. [PMID: 22265929 PMCID: PMC3294023 DOI: 10.1016/j.jinsphys.2012.01.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2011] [Revised: 01/05/2012] [Accepted: 01/09/2012] [Indexed: 05/31/2023]
Abstract
The effect of ecdysteroid signaling on Drosophila female precopulatory behavior was investigated using two types of mutants with either globally reduced ecdysteroid availability or reduced expression of ecdysone receptors in fruitless neurons, known to control sexual behavior. While being courted by males, mutant females performed significantly less full ovipositor extrusion behavior to reject male copulation attempts. Ecdysteroid depleted females (ecdysoneless(1)) performed male-like courtship behaviors, including unilateral wing extension and song production with patterns very similar to male courtship song. These results support the hypothesis that ecdysteroids modulate female sexual behavior, perhaps acting as a regulator of sexual motivation, and as a component affecting the performance of sex specific behavior patterns.
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Affiliation(s)
- G K Ganter
- Department of Biology, College of Arts and Sciences, University of New England, Biddeford, ME 04005, USA.
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Borja F, Fabre-Nys C. Brain structures involved in the sexual behaviour of Ile de France rams with different sexual preferences and levels of sexual activity. Behav Brain Res 2011; 226:411-9. [PMID: 21985862 DOI: 10.1016/j.bbr.2011.09.037] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2011] [Revised: 09/22/2011] [Accepted: 09/26/2011] [Indexed: 02/04/2023]
Abstract
Using Fos, as a marker, we analysed the brain structures of rams, with different libidos or sexual preferences that had been activated by contact with males or females. Ile de France rams aged from 1.5 to 7 years were used. Fos immunoreactivity (Fos IR) was analysed in rams with high (HL) or low libido (LL) after 90 min of direct contact with females (HL DirF n=7 or LL DirF n=7) or in rams of high libido having indirect contact through a fence, with females (HL IndF n=6) or males (HL IndM n=5) and finally, in males who preferred other males as partners by indirect contact through a fence with males (MO IndM n=4). Direct or indirect contact with a preferred sexual partner (LL DirF, HL Dir F, HL IndF, MO IndM) induced the appearance of Fos-IR cells in several diencephalic and cortical structures. Conversely, indirect contact with males did not induce Fos-IR in males interested in females (HL IndM). In the medial preoptic area (MPOA), the paraventricular nucleus and the medial bed nucleus of the stria terminalis the cell density of Fos IR cells was higher in HL Dir F than in LL DirF suggesting involvement in sexual motivation whereas only the MPOA seemed involved the consummatory component of sexual behaviour (Fos IR density HL DirF>HL IndF). The enthorinal cortex was the only structure specifically activated by males attracted to other males (Fos IR density MO IndM>HL IndM) whereas Fos IR density did not differ between the HL IndF and HL IndM groups.
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Affiliation(s)
- Fernando Borja
- UMR 6175 INRA Physiologie de la Reproduction et des Comportements, CNRS, Université de Tours, Institut du cheval et de l'équitation, 37380 Nouzilly, France
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Abstract
Many people believe that sexual orientation (homosexuality vs. heterosexuality) is determined by education and social constraints. There are, however, a large number of studies indicating that prenatal factors have an important influence on this critical feature of human sexuality. Sexual orientation is a sexually differentiated trait (over 90% of men are attracted to women and vice versa). In animals and men, many sexually differentiated characteristics are organized during early life by sex steroids, and one can wonder whether the same mechanism also affects human sexual orientation. Two types of evidence support this notion. First, multiple sexually differentiated behavioral, physiological, or even morphological traits are significantly different in homosexual and heterosexual populations. Because some of these traits are known to be organized by prenatal steroids, including testosterone, these differences suggest that homosexual subjects were, on average, exposed to atypical endocrine conditions during development. Second, clinical conditions associated with significant endocrine changes during embryonic life often result in an increased incidence of homosexuality. It seems therefore that the prenatal endocrine environment has a significant influence on human sexual orientation but a large fraction of the variance in this behavioral characteristic remains unexplained to date. Genetic differences affecting behavior either in a direct manner or by changing embryonic hormone secretion or action may also be involved. How these biological prenatal factors interact with postnatal social factors to determine life-long sexual orientation remains to be determined.
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Affiliation(s)
- Jacques Balthazart
- University of Liège, Groupe Interdisciplinaire de Génoprotéomique Appliquée Neurosciences, Research Group in Behavioral Neuroendocrinology, 1 Avenue de l'Hôpital (B36), B-4000 Liège, Belgium.
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