1
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Vujovic S. Transsexualism and hormones. Gynecol Endocrinol 2022; 38:355-356. [PMID: 35506459 DOI: 10.1080/09513590.2022.2067846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Affiliation(s)
- Svetlana Vujovic
- Faculty of Medicine, National Center for Infertility and Endocrinology of Gender, Clinic Of Endocrinology, Diabetes and Diseases of Metabolism, University Clinical Center, University of Belgrade, Belgrade, Serbia
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2
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Skorska MN, Coome LA, Peragine DE, Aitken M, VanderLaan DP. An anthropometric study of sexual orientation and gender identity in Thailand. Sci Rep 2021; 11:18432. [PMID: 34531440 PMCID: PMC8445993 DOI: 10.1038/s41598-021-97845-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 08/31/2021] [Indexed: 11/23/2022] Open
Abstract
The biodevelopment of psychological sex differentiation is putatively reflected in several anthropometrics. We examined eight anthropometrics in 1404 Thai participants varying in sex, sexual orientation, and gender identity/expression: heterosexual men and women, gay men, lesbian women, bisexual women, sao praphet song (transgender birth-assigned males), toms (transgender birth-assigned females), and dees (birth-assigned females attracted to toms). Exploratory factor analyses indicated the biomarkers should be analyzed independently. Using regressions, in birth-assigned males, less male-typical second-to-fourth digit ratios in the left hand were associated with sexual orientation towards men regardless of gender identity/expression, whereas shorter height and long-bone growth in the arms and legs were more evident among sao praphet song-who are both sexually oriented towards men and markedly feminine. In birth-assigned females, there were no clear sexual orientation effects, but there were possible gender-related effects. Groups of individuals who tend to be more masculine (i.e., toms, lesbians) showed more male-typical patterns on weight and leg length than some groups of individuals who tend to be less masculine (i.e., heterosexual women, dees). Thus, it appears the various anthropometrics inform separate biodevelopmental processes that differentially relate to sexual orientation and gender identity/expression depending on the measure in question as well as birth-assigned sex.
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Affiliation(s)
- Malvina N Skorska
- Child & Youth Psychiatry, Centre for Addiction and Mental Health, Toronto, ON, M6J 1H4, Canada
| | - Lindsay A Coome
- Department of Psychology, University of Toronto Mississauga, 3359 Mississauga Rd. N., Mississauga, ON, L5L 1C6, Canada
| | - Diana E Peragine
- Department of Psychology, University of Toronto Mississauga, 3359 Mississauga Rd. N., Mississauga, ON, L5L 1C6, Canada
| | - Madison Aitken
- Department of Psychiatry, University of Toronto, Toronto, ON, M5T 1R8, Canada
| | - Doug P VanderLaan
- Child & Youth Psychiatry, Centre for Addiction and Mental Health, Toronto, ON, M6J 1H4, Canada.
- Department of Psychology, University of Toronto Mississauga, 3359 Mississauga Rd. N., Mississauga, ON, L5L 1C6, Canada.
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3
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Baldinger-Melich P, Urquijo Castro MF, Seiger R, Ruef A, Dwyer DB, Kranz GS, Klöbl M, Kambeitz J, Kaufmann U, Windischberger C, Kasper S, Falkai P, Lanzenberger R, Koutsouleris N. Sex Matters: A Multivariate Pattern Analysis of Sex- and Gender-Related Neuroanatomical Differences in Cis- and Transgender Individuals Using Structural Magnetic Resonance Imaging. Cereb Cortex 2021; 30:1345-1356. [PMID: 31368487 PMCID: PMC7132951 DOI: 10.1093/cercor/bhz170] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 06/28/2019] [Accepted: 06/28/2019] [Indexed: 12/22/2022] Open
Abstract
Univariate analyses of structural neuroimaging data have produced heterogeneous results regarding anatomical sex- and gender-related differences. The current study aimed at delineating and cross-validating brain volumetric surrogates of sex and gender by comparing the structural magnetic resonance imaging data of cis- and transgender subjects using multivariate pattern analysis. Gray matter (GM) tissue maps of 29 transgender men, 23 transgender women, 35 cisgender women, and 34 cisgender men were created using voxel-based morphometry and analyzed using support vector classification. Generalizability of the models was estimated using repeated nested cross-validation. For external validation, significant models were applied to hormone-treated transgender subjects (n = 32) and individuals diagnosed with depression (n = 27). Sex was identified with a balanced accuracy (BAC) of 82.6% (false discovery rate [pFDR] < 0.001) in cisgender, but only with 67.5% (pFDR = 0.04) in transgender participants indicating differences in the neuroanatomical patterns associated with sex in transgender despite the major effect of sex on GM volume irrespective of the self-identification as a woman or man. Gender identity and gender incongruence could not be reliably identified (all pFDR > 0.05). The neuroanatomical signature of sex in cisgender did not interact with depressive features (BAC = 74.7%) but was affected by hormone therapy when applied in transgender women (P < 0.001).
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Affiliation(s)
- Pia Baldinger-Melich
- Department of Psychiatry and Psychotherapy, Clinical Division of General Psychiatry, Medical University of Vienna, Vienna, Austria.,Neuroimaging Labs (NIL) PET, MRI, EEG, TMS and Chemical Lab, Department of Psychiatry and Psychotherapy, Clinical Division of General Psychiatry, Medical University of Vienna, Vienna, Austria
| | - Maria F Urquijo Castro
- Department of Psychiatry and Psychotherapy, Ludwig-Maximilians-University, Munich, Bavaria, Germany.,Section for Neurodiagnostic Applications, Department of Psychiatry and Psychotherapy, Ludwig-Maximilians-University, Munich, Bavaria, Germany
| | - René Seiger
- Department of Psychiatry and Psychotherapy, Clinical Division of General Psychiatry, Medical University of Vienna, Vienna, Austria.,Neuroimaging Labs (NIL) PET, MRI, EEG, TMS and Chemical Lab, Department of Psychiatry and Psychotherapy, Clinical Division of General Psychiatry, Medical University of Vienna, Vienna, Austria
| | - Anne Ruef
- Department of Psychiatry and Psychotherapy, Ludwig-Maximilians-University, Munich, Bavaria, Germany.,Section for Neurodiagnostic Applications, Department of Psychiatry and Psychotherapy, Ludwig-Maximilians-University, Munich, Bavaria, Germany
| | - Dominic B Dwyer
- Department of Psychiatry and Psychotherapy, Ludwig-Maximilians-University, Munich, Bavaria, Germany.,Section for Neurodiagnostic Applications, Department of Psychiatry and Psychotherapy, Ludwig-Maximilians-University, Munich, Bavaria, Germany
| | - Georg S Kranz
- Department of Psychiatry and Psychotherapy, Clinical Division of General Psychiatry, Medical University of Vienna, Vienna, Austria.,Neuroimaging Labs (NIL) PET, MRI, EEG, TMS and Chemical Lab, Department of Psychiatry and Psychotherapy, Clinical Division of General Psychiatry, Medical University of Vienna, Vienna, Austria.,Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong
| | - Manfred Klöbl
- Department of Psychiatry and Psychotherapy, Clinical Division of General Psychiatry, Medical University of Vienna, Vienna, Austria
| | - Joseph Kambeitz
- Department of Psychiatry and Psychotherapy, Ludwig-Maximilians-University, Munich, Bavaria, Germany.,Section for Neurodiagnostic Applications, Department of Psychiatry and Psychotherapy, Ludwig-Maximilians-University, Munich, Bavaria, Germany
| | - Ulrike Kaufmann
- Department of Obstetrics and Gynecology, Medical University of Vienna, Vienna, Austria
| | - Christian Windischberger
- MR Centre of Excellence, Centre for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Siegfried Kasper
- Department of Psychiatry and Psychotherapy, Clinical Division of General Psychiatry, Medical University of Vienna, Vienna, Austria
| | - Peter Falkai
- Department of Psychiatry and Psychotherapy, Ludwig-Maximilians-University, Munich, Bavaria, Germany
| | - Rupert Lanzenberger
- Department of Psychiatry and Psychotherapy, Clinical Division of General Psychiatry, Medical University of Vienna, Vienna, Austria.,Neuroimaging Labs (NIL) PET, MRI, EEG, TMS and Chemical Lab, Department of Psychiatry and Psychotherapy, Clinical Division of General Psychiatry, Medical University of Vienna, Vienna, Austria
| | - Nikolaos Koutsouleris
- Department of Psychiatry and Psychotherapy, Ludwig-Maximilians-University, Munich, Bavaria, Germany.,Section for Neurodiagnostic Applications, Department of Psychiatry and Psychotherapy, Ludwig-Maximilians-University, Munich, Bavaria, Germany
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4
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Swaab DF, Wolff SEC, Bao AM. Sexual differentiation of the human hypothalamus: Relationship to gender identity and sexual orientation. HANDBOOK OF CLINICAL NEUROLOGY 2021; 181:427-443. [PMID: 34238476 DOI: 10.1016/b978-0-12-820683-6.00031-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Gender identity (an individual's perception of being male or female) and sexual orientation (heterosexuality, homosexuality, or bisexuality) are programmed into our brain during early development. During the intrauterine period in the second half of pregnancy, a testosterone surge masculinizes the fetal male brain. If such a testosterone surge does not occur, this will result in a feminine brain. As sexual differentiation of the brain takes place at a much later stage in development than sexual differentiation of the genitals, these two processes can be influenced independently of each other and can result in gender dysphoria. Nature produces a great variability for all aspects of sexual differentiation of the brain. Mechanisms involved in sexual differentiation of the brain include hormones, genetics, epigenetics, endocrine disruptors, immune response, and self-organization. Furthermore, structural and functional differences in the hypothalamus relating to gender dysphoria and sexual orientation are described in this review. All the genetic, postmortem, and in vivo scanning observations support the neurobiological theory about the origin of gender dysphoria, i.e., it is the sizes of brain structures, the neuron numbers, the molecular composition, functions, and connectivity of brain structures that determine our gender identity or sexual orientation. There is no evidence that one's postnatal social environment plays a crucial role in the development of gender identity or sexual orientation.
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Affiliation(s)
- Dick F Swaab
- Department Neuropsychiatric Disorders, Netherlands Institute for Neuroscience, An Institute of the Royal Netherlands Academy of Arts and Sciences, Amsterdam, The Netherlands
| | - Samantha E C Wolff
- Department Neuropsychiatric Disorders, Netherlands Institute for Neuroscience, An Institute of the Royal Netherlands Academy of Arts and Sciences, Amsterdam, The Netherlands
| | - Ai-Min Bao
- Department of Neurobiology and Department of Neurology of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China; NHC and CAMS Key Laboratory of Medical Neurobiology, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, China.
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5
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Balthazart J. Sexual partner preference in animals and humans. Neurosci Biobehav Rev 2020; 115:34-47. [PMID: 32450091 PMCID: PMC7484171 DOI: 10.1016/j.neubiorev.2020.03.024] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Revised: 03/11/2020] [Accepted: 03/24/2020] [Indexed: 12/25/2022]
Abstract
Sex differences in brain and behavior of animals including humans result from an interaction between biological and environmental influences. This is also true for the differences between men and women concerning sexual orientation. Sexual differentiation is mediated by three groups of biological mechanisms: early actions of sex steroids, more direct actions of sex-specific genes not mediated by gonadal sex steroids and epigenetic mechanisms. Differential interactions with parents and conspecifics have additionally long-term influences on behavior. This presentation reviews available evidence indicating that these different mechanisms play a significant role in the control of sexual partner preference in animals and humans, in other words the homosexual versus heterosexual orientation. Clinical and epidemiological studies of phenotypically selected populations indicate that early actions of hormones and genetic factors clearly contribute to the determination of sexual orientation. The maternal embryonic environment also modifies the incidence of male homosexuality via immunological mechanisms. The relative contribution of each of these mechanisms remains however to be determined.
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6
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Sigurdardottir HL, Lanzenberger R, Kranz GS. Genetics of sex differences in neuroanatomy and function. HANDBOOK OF CLINICAL NEUROLOGY 2020; 175:179-193. [PMID: 33008524 DOI: 10.1016/b978-0-444-64123-6.00013-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/25/2023]
Abstract
Sex differences are observed at many distinct biologic levels, such as in the anatomy and functioning of the brain, behavior, and susceptibility to neuropsychiatric disorders. Previously, these differences were believed to entirely result from the secretion of gonadal hormones; however, recent research has demonstrated that differences are also the consequence of direct or nonhormonal effects of genes located on the sex chromosomes. This chapter reviews the four core genotype model that separates the effects of hormones and sex chromosomes and highlights a few genes that are believed to be partly responsible for sex dimorphism of the brain, in particular, the Sry gene. Genetics of the brain's neurochemistry is discussed and the susceptibility to certain neurologic and psychiatric disorders is reviewed. Lastly, we discuss the sex-specific genetic contribution in disorders of sexual development. The precise molecular mechanisms underlying these differences are currently not entirely known. An increased knowledge and understanding of the role of candidate genes will undeniably be of great aid in elucidating the molecular basis of sex-biased disorders and potentially allow for more sex-specific therapies.
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Affiliation(s)
- Helen L Sigurdardottir
- Department of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria.
| | - Rupert Lanzenberger
- Department of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria
| | - Georg S Kranz
- Department of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria; Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hong Kong, People's Republic of China; The State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong, People's Republic of China
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7
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Rezzani R, Franco C, Rodella LF. Sex differences of brain and their implications for personalized therapy. Pharmacol Res 2019; 141:429-442. [PMID: 30659897 DOI: 10.1016/j.phrs.2019.01.030] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 01/14/2019] [Accepted: 01/15/2019] [Indexed: 01/06/2023]
Abstract
Nowadays, it is known that the sex differences regard many organs, e.g., liver, vessels, pancreas, lungs, bronchi and also the brain. Sex differences are not just a matter of ethical and moral principles, as they are central to explain many still unknown diseases and their understanding is a prerequisite to develop an effective therapy for each individual. This review reports on those sex differences that are not only macroscopic and morphological, but also involve molecular and functional dimorphism in the brain. It will recapitulate the main structural differences between male and female brain including the neurotransmission systems; in particular, the main objective is to identify a correlation, already known or to be investigated in the future, between the differences that characterize male and female brains from a morphological and biochemical point of view and neurological syndromes. This correlation could provide a starting point for future scientific research aimed to investigate and define a personalized therapy.
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Affiliation(s)
- Rita Rezzani
- Anatomy and Physiopathology Division, Department of Clinical and Experimental Sciences, University of Brescia, Viale Europa 11, 25123 Brescia, Italy; Interdipartimental University Center of Research "Adaption and Regeneration of Tissues and Organs-(ARTO)", University of Brescia, 25123 Brescia, Italy.
| | - Caterina Franco
- Anatomy and Physiopathology Division, Department of Clinical and Experimental Sciences, University of Brescia, Viale Europa 11, 25123 Brescia, Italy
| | - Luigi F Rodella
- Anatomy and Physiopathology Division, Department of Clinical and Experimental Sciences, University of Brescia, Viale Europa 11, 25123 Brescia, Italy; Interdipartimental University Center of Research "Adaption and Regeneration of Tissues and Organs-(ARTO)", University of Brescia, 25123 Brescia, Italy
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8
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O'Hanlan KA, Gordon JC, Sullivan MW. Biological origins of sexual orientation and gender identity: Impact on health. Gynecol Oncol 2018; 149:33-42. [PMID: 29605047 DOI: 10.1016/j.ygyno.2017.11.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 10/30/2017] [Accepted: 11/07/2017] [Indexed: 01/19/2023]
Abstract
Gynecologic Oncologists are sometimes consulted to care for patients who present with diverse gender identities or sexual orientations. Clinicians can create more helpful relationships with their patients if they understand the etiologies of these diverse expressions of sexual humanity. Multidisciplinary evidence reveals that a sexually dimorphic spectrum of somatic and neurologic anatomy, traits and abilities, including sexual orientation and gender identity, are conferred together during the first half of pregnancy due to genetics, epigenetics and the diversity of timing and function of sex chromosomes, sex-determining protein secretion, gonadal hormone secretion, receptor levels, adrenal function, maternally ingested dietary hormones, fetal health, and many other factors. Multiple layers of evidence confirm that sexual orientation and gender identity are as biological, innate and immutable as the other traits conferred during that critical time in gestation. Negative social responses to diverse orientations or gender identities have caused marginalization of these individuals with resultant alienation from medical care, reduced self-care and reduced access to medical care. The increased risks for many diseases, including gynecologic cancers are reviewed. Gynecologic Oncologists can potentially create more effective healthcare relationships with their patients if they have this information.
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Affiliation(s)
- Katherine A O'Hanlan
- Laparoscopic Institute for Gynecology and Oncology (LIGO), 4370 Alpine Rd. Suite 104, Portola Valley, CA 94028, United States.
| | - Jennifer C Gordon
- University of Tennessee Health Sciences Center, Memphis, TN, United States.
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9
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Balthazart J, Court L. Human Sexual Orientation: The Importance of Evidentiary Convergence. ARCHIVES OF SEXUAL BEHAVIOR 2017; 46:1595-1600. [PMID: 28500563 PMCID: PMC5532062 DOI: 10.1007/s10508-017-0997-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 05/02/2017] [Indexed: 05/26/2023]
Affiliation(s)
- Jacques Balthazart
- GIGA Neurosciences, University of Liège, 15 Avenue Hippocrate, 4000, Liège, Belgium.
| | - Lucas Court
- GIGA Neurosciences, University of Liège, 15 Avenue Hippocrate, 4000, Liège, Belgium
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10
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Balthazart J. Sex differences in partner preferences in humans and animals. Philos Trans R Soc Lond B Biol Sci 2016; 371:20150118. [PMID: 26833838 PMCID: PMC4785903 DOI: 10.1098/rstb.2015.0118] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/04/2015] [Indexed: 11/12/2022] Open
Abstract
A large number of morphological, physiological and behavioural traits are differentially expressed by males and females in all vertebrates including humans. These sex differences, sometimes, reflect the different hormonal environment of the adults, but they often remain present after subjects of both sexes are placed in the same endocrine conditions following gonadectomy associated or not with hormonal replacement therapy. They are then the result of combined influences of organizational actions of sex steroids acting early during development, or genetic differences between the sexes, or epigenetic mechanisms differentially affecting males and females. Sexual partner preference is a sexually differentiated behavioural trait that is clearly controlled in animals by the same type of mechanisms. This is also probably true in humans, even if critical experiments that would be needed to obtain scientific proof of this assertion are often impossible for pragmatic or ethical reasons. Clinical, epidemiological and correlative studies provide, however, converging evidence strongly suggesting, if not demonstrating, that endocrine, genetic and epigenetic mechanisms acting during the pre- or perinatal life control human sexual orientation, i.e. homosexuality versus heterosexuality. Whether they interact with postnatal psychosexual influences remains, however, unclear at present.
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Affiliation(s)
- Jacques Balthazart
- GIGA Neurosciences, University of Liège, 15 avenue Hippocrate, 4000 Liège, Belgium
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11
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Abstract
Gender dysphoria (GD), a term that denotes persistent discomfort with one's biologic sex or assigned gender, replaced the diagnosis of gender identity disorder in the Diagnostic and Statistical Manual of Mental Disorders in 2013. Subtypes of GD in adults, defined by sexual orientation and age of onset, have been described; these display different developmental trajectories and prognoses. Prevalence studies conclude that fewer than 1 in 10,000 adult natal males and 1 in 30,000 adult natal females experience GD, but such estimates vary widely. GD in adults is associated with an elevated prevalence of comorbid psychopathology, especially mood disorders, anxiety disorders, and suicidality. Causal mechanisms in GD are incompletely understood, but genetic, neurodevelopmental, and psychosocial factors probably all contribute. Treatment of GD in adults, although largely standardized, is likely to evolve in response to the increasing diversity of persons seeking treatment, demands for greater client autonomy, and improved understanding of the benefits and limitations of current treatment modalities.
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Affiliation(s)
- Kenneth J Zucker
- Gender Identity Clinic, Child, Youth, and Family Services, Centre for Addiction and Mental Health and Department of Psychiatry, University of Toronto, Toronto, Ontario M5T 1R8, Canada;
| | - Anne A Lawrence
- Department of Psychology, University of Lethbridge, Lethbridge, Alberta T1K 3M4, Canada
| | - Baudewijntje P C Kreukels
- Department of Medical Psychology, VU University Medical Center and EMGO Institute for Health and Care Research, Amsterdam 1081 HV, The Netherlands
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12
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de Sousa MBC, Galvão ACDM, Sales CJR, de Castro DC, Galvão-Coelho NL. Endocrine and Cognitive Adaptations to Cope with Stress in Immature Common Marmosets (Callithrix jacchus): Sex and Age Matter. Front Psychiatry 2015; 6:160. [PMID: 26648876 PMCID: PMC4663272 DOI: 10.3389/fpsyt.2015.00160] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Accepted: 10/26/2015] [Indexed: 11/20/2022] Open
Abstract
Phenotypic sex differences in primates are associated with body differentiation during the early stages of life, expressed in both physiological and behavioral features. Hormones seem to play a pivotal role in creating a range of responses to meet environmental and social demands, resulting in better reactions to cope with challenges to survival and reproduction. Steroid hormones actively participate in neuroplasticity and steroids from both gonads and neurons seem to be involved in behavioral modulation in primates. Indirect evidence suggests the participation of sexual steroids in dimorphism of the stress response in common marmosets. This species is an important experimental model in psychiatry, and we found a dual profile for cortisol in the transition from juvenile to subadult, with females showing higher levels. Immature males and females at 6 and 9 months of age moved alone from the family group to a new cage, over a 21-day period, expressed distinct patterns of cortisol variation with respect to range and duration of response. Additional evidence showed that at 12 months of age, males and females buffered the hypothalamic-pituitary-adrenal axis during chronic stress. Moreover, chronic stressed juvenile marmoset males showed better cognitive performance in working memory tests and motivation when compared to those submitted to short-term stress living in family groups. Thus, as cortisol profile seems to be sexually dimorphic before adulthood, age and sex are critical variables to consider in approaches that require immature marmosets in their experimental protocols. Moreover, available cognitive tests should be scrutinized to allow better investigation of cognitive traits in this species.
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13
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Fernández R, Esteva I, Gómez‐Gil E, Rumbo T, Almaraz MC, Roda E, Haro‐Mora J, Guillamón A, Pásaro E. The (CA)n Polymorphism of ERβ Gene is Associated with FtM Transsexualism. J Sex Med 2014; 11:720-8. [DOI: 10.1111/jsm.12398] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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14
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Neuroethology of male courtship in Drosophila: from the gene to behavior. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2014; 200:251-64. [PMID: 24567257 DOI: 10.1007/s00359-014-0891-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Revised: 08/29/2013] [Accepted: 02/11/2014] [Indexed: 01/01/2023]
Abstract
Neurogenetic analyses in the fruit fly Drosophila melanogaster revealed that gendered behaviors, including courtship, are underpinned by sexually dimorphic neural circuitries, whose development is directed in a sex-specific manner by transcription factor genes, fruitless (fru) and doublesex (dsx), two core members composing the sex-determination cascade. Via chromatin modification the Fru proteins translated specifically in the male nervous system lead the fru-expressing neurons to take on the male fate, as manifested by their male-specific survival or male-specific neurite formations. One such male-specific neuron group, P1, was shown to be activated when the male taps the female abdomen. Moreover, when artificially activated, P1 neurons are sufficient to induce the entire repertoire of the male courtship ritual. These studies provide a conceptual framework for understanding how the genetic code for innate behavior can be embodied in the neuronal substrate.
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Nováková L, Varella Valentová J, Havlíček J. Olfactory performance is predicted by individual sex-atypicality, but not sexual orientation. PLoS One 2013; 8:e80234. [PMID: 24244657 PMCID: PMC3820642 DOI: 10.1371/journal.pone.0080234] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Accepted: 10/01/2013] [Indexed: 11/19/2022] Open
Abstract
Many previous studies have reported robust sex differences in olfactory perception. However, both men and women can be expected to vary in the degree to which they exhibit olfactory performance considered typical of their own or the opposite sex. Sex-atypicality is often described in terms of childhood gender nonconformity, which, however, is not a perfect correlate of non-heterosexual orientation. Here we explored intrasexual variability in psychophysical olfactory performance in a sample of 156 individuals (83 non-heterosexual) and found the lowest odor identification scores in heterosexual men. However, when childhood gender nonconformity was entered in the model along with sexual orientation, better odor identification scores were exhibited by gender-nonconforming men, and greater olfactory sensitivity by gender-conforming women, irrespective of their sexual orientation. Thus, sex-atypicality, but not sexual orientation predicts olfactory performance, and we propose that this might not be limited to olfaction, but represent a more general phenomenon.
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Affiliation(s)
- Lenka Nováková
- Department of Anthropology, Faculty of Humanities, Charles University, Prague, Czech Republic, United States of America
- * E-mail:
| | - Jaroslava Varella Valentová
- Centre for Theoretical Study, Charles University and the Academy of Sciences of the CzechRepublic, Prague, Czech Republic, United States of America
| | - Jan Havlíček
- Department of Zoology, Faculty of Science, Charles University, Prague, Czech Republic, United States of America
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16
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High prevalence of brain pathology in violent prisoners: a qualitative CT and MRI scan study. Eur Arch Psychiatry Clin Neurosci 2013; 263:607-16. [PMID: 23568089 DOI: 10.1007/s00406-013-0403-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Accepted: 03/18/2013] [Indexed: 10/27/2022]
Abstract
The aim of this study was to determine the frequency and extent of brain anomalies in a large sample of incarcerated violent offenders not previously considered neuropsychiatrically ill, in comparison with non-violent offenders and non-offending controls. MRI and CT brain scans from 287 male prison inmates (162 violent and 125 non-violent) not diagnosed as mentally ill before that were obtained due to headache, vertigo or psychological complaints during imprisonment were assessed and compared to 52 non-criminal controls. Brain scans were rated qualitatively with respect to evidence of structural brain damage. Each case received a semiquantitative rating of "normal" (=0), "questionably abnormal" (=1) or "definitely abnormal" (=2) for the lateral ventricles, frontal/parietal cortex and medial temporal structures bilaterally as well as third ventricle. Overall, offenders displayed a significantly higher rate of morphological abnormality, with the violent offenders scoring significantly higher than non-violent offenders and controls. This difference was statistically detectable for frontal/parietal cortex, medial temporal structures, third ventricle and the left but not the right lateral ventricle. The remarkable prevalence of brain pathology in convicted violent prisoners detectable by neuroradiological routine assessment not only highlights the importance of frontal and temporal structures in the control of social, and specifically of violent behaviour, but also raises questions on the legal culpability of violent offenders with brain abnormalities. The high proportion of undetected presence of structural brain damage emphasizes the need that in violent criminals, the comprehensive routine neuropsychiatric assessment usually performed in routine forensic psychiatric expertises should be complemented with brain imaging.
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Groh D, Seeman P, Jilek M, Popelář J, Kabelka Z, Syka J. Hearing function in heterozygous carriers of a pathogenic GJB2 gene mutation. Physiol Res 2013; 62:323-30. [PMID: 23489192 DOI: 10.33549/physiolres.932475] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The most frequent hereditary hearing loss is caused by mutations in the GJB2 gene coding for the gap junction beta 2 protein Connexin 26 (Cx26). In contrast to many studies performed in patients with bi-allelic mutations, audiometric studies on heterozygotes are sparse and often contradictory. To evaluate hearing function in heterozygous carriers of the GJB2 c.35delG mutation, audiometry over the extended frequency range and the recording of otoacoustic emissions (OAEs), i.e., transient-evoked OAEs (TEOAEs) and distortion product OAEs (DPOAEs), were performed in a group of parents and grandparents of deaf children homozygous for the GJB2 c.35delG mutation. The comparison of audiograms between control and heterozygous subjects was enabled using audiogram normalization for age and sex. Hearing loss, estimated with this procedure, was found to be significantly larger in GJB2 c.35delG heterozygous females in comparison with controls for the frequencies of 8-16 kHz; the deterioration of hearing in heterozygous men in comparison with controls was not statistically significant. A comparison of TEOAE responses and DPOAE levels between GJB2 c.35delG heterozygotes and controls did not reveal any significant differences. The results prove the importance of using audiometry over the extended frequency range and audiogram normalization for age and sex to detect minor hearing impairments, even in a relatively small group of subjects of different ages.
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Affiliation(s)
- D Groh
- Department of ENT, Charles University in Prague, Second Faculty of Medicine, Prague, Czech Republic.
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Zhang X, Sui Z. Deciphering the selective androgen receptor modulators paradigm. Expert Opin Drug Discov 2012; 8:191-218. [DOI: 10.1517/17460441.2013.741582] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Affiliation(s)
- Xuqing Zhang
- Janssen Research and Development, LLC, Welsh and McKean Roads, PO Box 776, Spring House, PA 19477, USA
| | - Zhihua Sui
- Janssen Research and Development, LLC, Welsh and McKean Roads, PO Box 776, Spring House, PA 19477, USA
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Lei X, Chen C, He Q, Chen C, Moyzis RK, Xue G, Chen X, Cao Z, Li J, Li H, Zhu B, Chun Hsu AS, Li S, Li J, Dong Q. Sex determines which section of the SLC6A4 gene is linked to obsessive-compulsive symptoms in normal Chinese college students. J Psychiatr Res 2012; 46:1153-60. [PMID: 22727904 DOI: 10.1016/j.jpsychires.2012.05.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2012] [Revised: 04/17/2012] [Accepted: 05/03/2012] [Indexed: 12/16/2022]
Abstract
Previous case-control and family-based association studies have implicated the SLC6A4 gene in obsessive-compulsive disorder (OCD). Little research, however, has examined this gene's role in obsessive-compulsive symptoms (OCS) in community samples. The present study genotyped seven tag SNPs and two common functional tandem repeat polymorphisms (5-HTTLPR and STin2), which together cover the whole SLC6A4 gene, and investigated their associations with OCS in normal Chinese college students (N = 572). The results revealed a significant gender main effect and gender-specific genetic effects of the SLC6A4 gene on OCS. Males scored significantly higher on total OCS and its three dimensions than did females (ps < .01). The 5-HTTLPR in the promoter region showed a female-specific genetic effect, with the l/l and l/s genotypes linked to higher OCS scores than the s/s genotype (ps < .05). In contrast, a conserved haplotype polymorphism (rs1042173| rs4325622| rs3794808| rs140701| rs4583306| rs2020942) covering from intron 3 to the 3' UTR of the SLC6A4 gene showed male-specific genetic effects, with the CGAAGG/CGAAGG genotype associated with lower OCS scores than the other genotypes (ps < .05). These effects remained significant after controlling for OCS-related factors including participants' depressive and anxiety symptoms as well as stressful life events, and correction for multiple tests. These results are discussed in terms of their implications for our understanding of the sex-specific role of the different sections of the SLC6A4 gene in OCD.
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Affiliation(s)
- Xuemei Lei
- State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing 100875, China.
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Guías de práctica clínica para la valoración y tratamiento de la transexualidad. Grupo de Identidad y Diferenciación Sexual de la SEEN (GIDSEEN)*(anexo 1). ACTA ACUST UNITED AC 2012; 59:367-82. [DOI: 10.1016/j.endonu.2012.02.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2012] [Revised: 02/02/2012] [Accepted: 02/06/2012] [Indexed: 11/18/2022]
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Abstract
The fruitless (fru) gene in Drosophila plays a pivotal role in the formation of neural circuits underlying gender-specific behaviors. Specific labeling of fru expressing neurons has revealed a core circuit responsible for male courtship behavior.Females with a small number of masculinized neuronal clusters in their brain can initiate male-type courtship behavior. By examining the correlations between the masculinized neurons and behavioral gender type, a male-specific neuronal cluster,named P1, which coexpresses fru and double sex, was identified as a putative trigger center for male-type courtship behavior. P1 neurons extend dendrite to the lateral horn,where multimodal sensory inputs converge. Molecular studies suggest that fru determines the level of masculinization of neurons by orchestrating the transcription of a set of downstream genes, which remain to be identified.
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Affiliation(s)
- Daisuke Yamamoto
- Division of Neurogenetics, Tohoku University Graduate School of Life Sciences,Sendai, Japan.
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Vigil P, Orellana RF, Cortés ME, Molina CT, Switzer BE, Klaus H. Endocrine modulation of the adolescent brain: a review. J Pediatr Adolesc Gynecol 2011; 24:330-7. [PMID: 21514192 DOI: 10.1016/j.jpag.2011.01.061] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2010] [Accepted: 01/28/2011] [Indexed: 12/31/2022]
Abstract
Neurophysiological and behavioral development is particularly complex in adolescence. Youngsters experience strong emotions and impulsivity, reduced self-control, and preference for actions which offer immediate rewards, among other behavioral patterns. Given the growing interest in endocrine effects on adolescent central nervous system development and their implications on later stages of life, this article reviews the effects of gonadal steroid hormones on the adolescent brain. These effects are classified as organizational, the capacity of steroids to determine nervous system structure during development, and activational, the ability of steroids to modify nervous activity to promote certain behaviors. During transition from puberty to adolescence, steroid hormones trigger various organizational phenomena related to structural brain circuit remodelling, determining adult behavioral response to steroids or sensory stimuli. These changes account for most male-female sexual dimorphism. In this stage sex steroids are involved in the main functional mechanisms responsible for organizational changes, namely myelination, neural pruning, apoptosis, and dendritic spine remodelling, activated only during embryonic development and during the transition from puberty to adolescence. This stage becomes a critical organizational window when the appropriately and timely exerted functions of steroid hormones and their interaction with some neurotransmitters on adolescent brain development are fundamental. Thus, understanding the phenomena linking steroid hormones and adolescent brain organization is crucial in the study of teenage behavior and in later assessment and treatment of anxiety, mood disorders, and depression. Adolescent behavior clearly evidences a stage of brain development influenced for the most part by steroid hormones.
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Affiliation(s)
- Pilar Vigil
- Unidad de Reproducción y Desarrollo, Departamento de Fisiología, Facultad de Ciencias Biológicas, Santiago, Pontificia Universidad Católica de Chile, Chile.
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Siehr MS, Koo PK, Sherlekar AL, Bian X, Bunkers MR, Miller RM, Portman DS, Lints R. Multiple doublesex-related genes specify critical cell fates in a C. elegans male neural circuit. PLoS One 2011; 6:e26811. [PMID: 22069471 PMCID: PMC3206049 DOI: 10.1371/journal.pone.0026811] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2011] [Accepted: 10/04/2011] [Indexed: 11/18/2022] Open
Abstract
Background In most animal species, males and females exhibit differences in behavior and morphology that relate to their respective roles in reproduction. DM (Doublesex/MAB-3) domain transcription factors are phylogenetically conserved regulators of sexual development. They are thought to establish sexual traits by sex-specifically modifying the activity of general developmental programs. However, there are few examples where the details of these interactions are known, particularly in the nervous system. Methodology/Principal Findings In this study, we show that two C. elegans DM domain genes, dmd-3 and mab-23, regulate sensory and muscle cell development in a male neural circuit required for mating. Using genetic approaches, we show that in the circuit sensory neurons, dmd-3 and mab-23 establish the correct pattern of dopaminergic (DA) and cholinergic (ACh) fate. We find that the ETS-domain transcription factor gene ast-1, a non-sex-specific, phylogenetically conserved activator of dopamine biosynthesis gene transcription, is broadly expressed in the circuit sensory neuron population. However, dmd-3 and mab-23 repress its activity in most cells, promoting ACh fate instead. A subset of neurons, preferentially exposed to a TGF-beta ligand, escape this repression because signal transduction pathway activity in these cells blocks dmd-3/mab-23 function, allowing DA fate to be established. Through optogenetic and pharmacological approaches, we show that the sensory and muscle cell characteristics controlled by dmd-3 and mab-23 are crucial for circuit function. Conclusions/Significance In the C. elegans male, DM domain genes dmd-3 and mab-23 regulate expression of cell sub-type characteristics that are critical for mating success. In particular, these factors limit the number of DA neurons in the male nervous system by sex-specifically regulating a phylogenetically conserved dopamine biosynthesis gene transcription factor. Homologous interactions between vertebrate counterparts could regulate sex differences in neuron sub-type populations in the brain.
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Affiliation(s)
- Meagan S. Siehr
- Department of Biology, Texas A & M University, College Station, Texas, United States of America
| | - Pamela K. Koo
- Department of Biology, Texas A & M University, College Station, Texas, United States of America
| | - Amrita L. Sherlekar
- Department of Biology, Texas A & M University, College Station, Texas, United States of America
| | - Xuelin Bian
- Department of Biology, Texas A & M University, College Station, Texas, United States of America
| | - Meredith R. Bunkers
- Department of Biology, Texas A & M University, College Station, Texas, United States of America
| | - Renee M. Miller
- Department of Biomedical Genetics, Center for Neural Development and Disease, University of Rochester, Rochester, New York, United States of America
| | - Douglas S. Portman
- Department of Biomedical Genetics, Center for Neural Development and Disease, University of Rochester, Rochester, New York, United States of America
| | - Robyn Lints
- Department of Biology, Texas A & M University, College Station, Texas, United States of America
- * E-mail:
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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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Brabant G, Cain J, Jackson A, Kreitschmann-Andermahr I. Visualizing hormone actions in the brain. Trends Endocrinol Metab 2011; 22:153-63. [PMID: 21497512 DOI: 10.1016/j.tem.2011.01.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2010] [Revised: 01/19/2011] [Accepted: 01/20/2011] [Indexed: 01/01/2023]
Abstract
Profound and multifaceted effects of hormones on the development, maturation and function of the CNS are well documented. Recent developments in magnetic resonance imagining (MRI) and positron emission tomography (PET) permit detailed in vivo studies of cerebral structure and function in humans. Techniques to measure subtle differences in cerebral structure, regional brain activation, changes in blood flow and other physiological biomarkers allow us to translate experimental evidence of hormone effects obtained from animal models to humans. Here we review the imaging techniques available to support studies of hormone effects on the CNS, emphasizing the recent developments of MRI. In summarizing the major current studies we discuss the potential of these techniques for an emerging new field in endocrinology.
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Affiliation(s)
- Georg Brabant
- Department of Endocrinology, The Christie, Manchester Academic Health Science Centre, Wilmslow Road, Manchester M20 4BX, UK.
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27
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Bao AM, Swaab DF. Sexual differentiation of the human brain: relation to gender identity, sexual orientation and neuropsychiatric disorders. Front Neuroendocrinol 2011; 32:214-26. [PMID: 21334362 DOI: 10.1016/j.yfrne.2011.02.007] [Citation(s) in RCA: 204] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2010] [Revised: 02/04/2011] [Accepted: 02/14/2011] [Indexed: 11/28/2022]
Abstract
During the intrauterine period a testosterone surge masculinizes the fetal brain, whereas the absence of such a surge results in a feminine brain. As sexual differentiation of the brain takes place at a much later stage in development than sexual differentiation of the genitals, these two processes can be influenced independently of each other. Sex differences in cognition, gender identity (an individual's perception of their own sexual identity), sexual orientation (heterosexuality, homosexuality or bisexuality), and the risks of developing neuropsychiatric disorders are programmed into our brain during early development. There is no evidence that one's postnatal social environment plays a crucial role in gender identity or sexual orientation. We discuss the relationships between structural and functional sex differences of various brain areas and the way they change along with any changes in the supply of sex hormones on the one hand and sex differences in behavior in health and disease on the other.
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Affiliation(s)
- Ai-Min Bao
- Department of Neurobiology, Key Laboratory of Medical Neurobiology of Ministry of Health of China, Zhejiang Province Key Laboratory of Neurobiology, Zhejiang University School of Medicine, Hangzhou, China.
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28
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Bao AM, Swaab DF. Sex differences in the brain, behavior, and neuropsychiatric disorders. Neuroscientist 2011; 16:550-65. [PMID: 20889965 DOI: 10.1177/1073858410377005] [Citation(s) in RCA: 138] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Sex differences in the brain are reflected in behavior and in the risk for neuropsychiatric disorders. The fetal brain develops in the male direction due to a direct effect of testosterone on the developing neurons, or in the female direction due to the absence of such a testosterone surge. Because sexual differentiation of the genitals takes place earlier in intrauterine life than sexual differentiation of the brain, these two processes can be influenced independently of each other. Gender identity (the conviction of belonging to the male or female gender), sexual orientation (heterosexuality, homosexuality, or bisexuality), pedophilia, sex differences in cognition, and the risks for neuropsychiatric disorders are programmed into our brains during early development. There is no proof that postnatal social environment has any crucial effect on gender identity or sexual orientation. Structural and functional sex differences in brain areas, together with changes in sex hormone levels and their receptors in development and adulthood, are closely related to sex differences in behavior and neuropsychiatric disorders. Knowing that such a relationship exists may help bring about sex-specific therapeutic strategies.
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Affiliation(s)
- Ai-Min Bao
- Department of Neurobiology, Institute of Neuroscience, Zhejiang University School of Medicine, Hangzhou, China.
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29
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Tsukamura H, Homma T, Tomikawa J, Uenoyama Y, Maeda KI. Sexual differentiation of kisspeptin neurons responsible for sex difference in gonadotropin release in rats. Ann N Y Acad Sci 2010; 1200:95-103. [DOI: 10.1111/j.1749-6632.2010.05645.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Gillies GE, McArthur S. Estrogen actions in the brain and the basis for differential action in men and women: a case for sex-specific medicines. Pharmacol Rev 2010; 62:155-98. [PMID: 20392807 PMCID: PMC2879914 DOI: 10.1124/pr.109.002071] [Citation(s) in RCA: 472] [Impact Index Per Article: 33.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The classic view of estrogen actions in the brain was confined to regulation of ovulation and reproductive behavior in the female of all mammalian species studied, including humans. Burgeoning evidence now documents profound effects of estrogens on learning, memory, and mood as well as neurodevelopmental and neurodegenerative processes. Most data derive from studies in females, but there is mounting recognition that estrogens play important roles in the male brain, where they can be generated from circulating testosterone by local aromatase enzymes or synthesized de novo by neurons and glia. Estrogen-based therapy therefore holds considerable promise for brain disorders that affect both men and women. However, as investigations are beginning to consider the role of estrogens in the male brain more carefully, it emerges that they have different, even opposite, effects as well as similar effects in male and female brains. This review focuses on these differences, including sex dimorphisms in the ability of estradiol to influence synaptic plasticity, neurotransmission, neurodegeneration, and cognition, which, we argue, are due in a large part to sex differences in the organization of the underlying circuitry. There are notable sex differences in the incidence and manifestations of virtually all central nervous system disorders, including neurodegenerative disease (Parkinson's and Alzheimer's), drug abuse, anxiety, and depression. Understanding the cellular and molecular basis of sex differences in brain physiology and responses to estrogen and estrogen mimics is, therefore, vitally important for understanding the nature and origins of sex-specific pathological conditions and for designing novel hormone-based therapeutic agents that will have optimal effectiveness in men or women.
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Affiliation(s)
- Glenda E Gillies
- Centre for Neuroscience, Department of Medicine, Hammersmith Hospital, Imperial College Faculty of Medicine, DuCane Road, London W12ONN, UK.
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Savic I, Garcia-Falgueras A, Swaab DF. Sexual differentiation of the human brain in relation to gender identity and sexual orientation. PROGRESS IN BRAIN RESEARCH 2010; 186:41-62. [DOI: 10.1016/b978-0-444-53630-3.00004-x] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Hembree WC, Cohen-Kettenis P, Delemarre-van de Waal HA, Gooren LJ, Meyer WJ, Spack NP, Tangpricha V, Montori VM. Endocrine treatment of transsexual persons: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab 2009; 94:3132-54. [PMID: 19509099 DOI: 10.1210/jc.2009-0345] [Citation(s) in RCA: 610] [Impact Index Per Article: 40.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVE The aim was to formulate practice guidelines for endocrine treatment of transsexual persons. EVIDENCE This evidence-based guideline was developed using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) system to describe the strength of recommendations and the quality of evidence, which was low or very low. CONSENSUS PROCESS Committees and members of The Endocrine Society, European Society of Endocrinology, European Society for Paediatric Endocrinology, Lawson Wilkins Pediatric Endocrine Society, and World Professional Association for Transgender Health commented on preliminary drafts of these guidelines. CONCLUSIONS Transsexual persons seeking to develop the physical characteristics of the desired gender require a safe, effective hormone regimen that will 1) suppress endogenous hormone secretion determined by the person's genetic/biologic sex and 2) maintain sex hormone levels within the normal range for the person's desired gender. A mental health professional (MHP) must recommend endocrine treatment and participate in ongoing care throughout the endocrine transition and decision for surgical sex reassignment. The endocrinologist must confirm the diagnostic criteria the MHP used to make these recommendations. Because a diagnosis of transsexualism in a prepubertal child cannot be made with certainty, we do not recommend endocrine treatment of prepubertal children. We recommend treating transsexual adolescents (Tanner stage 2) by suppressing puberty with GnRH analogues until age 16 years old, after which cross-sex hormones may be given. We suggest suppressing endogenous sex hormones, maintaining physiologic levels of gender-appropriate sex hormones and monitoring for known risks in adult transsexual persons.
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Affiliation(s)
- Wylie C Hembree
- The Endocrine Society, 8401 Connecticut Avenue, Suite 900, Chevy Chase, Maryland, USA
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The effect of increased serotonergic neurotransmission on aggression: a critical meta-analytical review of preclinical studies. Psychopharmacology (Berl) 2009; 205:349-68. [PMID: 19404614 DOI: 10.1007/s00213-009-1543-2] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2008] [Accepted: 04/08/2009] [Indexed: 12/28/2022]
Abstract
RATIONALE The role of serotonin (5-HT) on aggression has been extensively studied; nonetheless, the role of this neurotransmitter in aggression is still inconclusive. OBJECTIVES The current meta-analytical review investigated the role of increased 5-HT neurotransmission in aggression. METHODS Preclinical studies using serotonin reuptake inhibitors, 5-hydroxytryptophan, L-tryptophan, or serotonin (5-HT) to increase 5-HT levels were included in this meta-analysis. An overall effect of serotonin on aggression was calculated, and the role of several moderator variables was analyzed. RESULTS A total of 218 effect sizes revealed that increased 5-HT had an overall significant inhibitory effect on aggression (r = 0.3). The results showed that increased 5-HT had the strongest inhibitory effect on aggression when (1) a specific strain or species (e.g., Long Evans) was used; (2) aggression was offensive or predatory and/or induced by administration of 5,7-dihydroxytryptamine or p-chlorophenylalanine; (3) zimelidine, sertraline, L-tryptophan, citalopram, or 5-HT were used to increase 5-HT; (4) treatment was acute; (5) long chronic treatment durations were used; and (6) time between last injection and behavior testing was within 8 h before or after peak plasma concentration of drug. In contrast, the results revealed that increased-5-HT-facilitated aggression could be predicted when (1) Wistar rats, (2) social isolation or stress to induce aggression, and/or (3) animals treated for less than 3 weeks were used. CONCLUSIONS Although 5-HT has an overall inhibitory effect on aggression, the animal's genetic background, drug, treatment time, aggression inducing paradigm, and aggression type are critical variables that influence and modify this effect.
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da Silva Lara LA, Useche B, Rosa E Silva JC, Ferriani RA, Reis RM, de Sá MFS, de Carvalho BR, Carvalho MACR, de Sá Rosa E Silva ACJ. Sexuality during the climacteric period. Maturitas 2009; 62:127-33. [PMID: 19186014 DOI: 10.1016/j.maturitas.2008.12.014] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2008] [Revised: 12/19/2008] [Accepted: 12/21/2008] [Indexed: 11/26/2022]
Abstract
BACKGROUND Cultural, social, physiological and psychological factors may alter the course of sexual function in climacteric women. OBJECTIVE The objective of the present literature review is to survey the prevalence of sexual dysfunctions in the climacteric and to establish the association between the organic and psychic changes that occur during this phase and sexual dysfunction. We also discuss potential treatments. METHODS We evaluated the data available in PubMed (1982-2008). For each original article, two reviewers analyzed the data independently and considered a study to be of high quality if it had all three of the following characteristics: prospective design, valid data and adequate sample size. Both reviewers extracted data from each of the 99 studies selected: 34 cross-sectional studies, 25 cohort studies, 9 trials, 31 reviews related to sexuality in pre- and post-menopausal women. RESULTS Sexual dysfunction among climacteric women is widespread and is associated with bio-psychosocial factors. However, there is not enough evidence to correlate sexual dysfunction with a decrease in estrogen levels and biological aging. A strong association exists between climacteric genital symptoms and coital pain. There is, however, sufficient evidence demonstrating the benefits of local estrogen therapy for patients with genital symptoms. CONCLUSION A significant decline in sexual function occurs in climacteric women, although it is still unclear whether this is associated with the known decrease in estrogen levels or with aging, or both. Relational factors may interfere with sexual function during this phase. The climacteric genital symptoms improve with estrogen replacement therapy, and positively influence sexual function. Further studies are needed to establish the actual impact of the decrease in estrogen levels and of aging on the sex life of climacteric women.
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Affiliation(s)
- Lucia Alves da Silva Lara
- Department of Gynecology and Obstetrics, Faculdade de Medicina de Ribeirão Preto, São Paulo University, Brazil-University Hospital, 14049-900 Ribeirão Preto, SP, Brazil.
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Willott JF. Effects of sex, gonadal hormones, and augmented acoustic environments on sensorineural hearing loss and the central auditory system: insights from research on C57BL/6J mice. Hear Res 2008; 252:89-99. [PMID: 19114100 DOI: 10.1016/j.heares.2008.12.002] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2008] [Revised: 11/24/2008] [Accepted: 12/01/2008] [Indexed: 11/26/2022]
Abstract
Mice of the C57BL/6J (B6) inbred strain exhibit genetic progressive sensorineural hearing loss and have been widely used as a model of adult-onset hearing loss and presbycusis. Males and females exhibit similar degrees of hearing loss until about 3 months of age, after which, the loss accelerates in females. This paper reviews research on how the B6 auditory system is affected by sex, gonadectomy (i.e., a reduction of gonadal hormone levels), and nightly exposure to moderately intense augmented acoustic environments (AAEs) - a low-frequency noise band (LAAE) or high-frequency band (HAAE). Several findings indicate a negative effect of ovarian hormones on the female B6 auditory system. Whereas the sex difference in high-frequency hearing loss was not significantly affected by gondadectomies, the female disadvantage in ABR thresholds at lower frequencies was erased by ovariectomy. Moreover, exposure to the LAAE or HAAE caused losses of hair cells that were more severe in intact females than in ovariectomized females or in males. Finally, intact females had more severe loss of neurons in the low-frequency region of the anterior ventral cochlear nucleus (AVCN) than other groups. In contrast, the presence of androgens had beneficial effects. Loss of hair cells and AVCN neurons after AAE exposure were more severe in orchidectomized males than in intact males. Ideas, hypotheses, and potential mechanisms concerning the findings are discussed.
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Affiliation(s)
- James F Willott
- Department of Psychology, University of South Florida, 4202 E. Fowler Ave., PCD4118G, Tampa, FL 33620, USA; The Jackson Laboratory, Bar Harbor, ME 04609, USA.
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Narayanan R, Mohler ML, Bohl CE, Miller DD, Dalton JT. Selective androgen receptor modulators in preclinical and clinical development. NUCLEAR RECEPTOR SIGNALING 2008; 6:e010. [PMID: 19079612 PMCID: PMC2602589 DOI: 10.1621/nrs.06010] [Citation(s) in RCA: 121] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/28/2008] [Accepted: 11/12/2008] [Indexed: 01/09/2023]
Abstract
Androgen receptor (AR) plays a critical role in the function of several organs including primary and accessory sexual organs, skeletal muscle, and bone, making it a desirable therapeutic target. Selective androgen receptor modulators (SARMs) bind to the AR and demonstrate osteo- and myo-anabolic activity; however, unlike testosterone and other anabolic steroids, these nonsteroidal agents produce less of a growth effect on prostate and other secondary sexual organs. SARMs provide therapeutic opportunities in a variety of diseases, including muscle wasting associated with burns, cancer, or end-stage renal disease, osteoporosis, frailty, and hypogonadism. This review summarizes the current standing of research and development of SARMs, crystallography of AR with SARMs, plausible mechanisms for their action and the potential therapeutic indications for this emerging class of drugs.
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Affiliation(s)
- Ramesh Narayanan
- Preclinical Research and Development, GTx, Inc., Memphis, Tennessee, USA
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Abstract
INTRODUCTION Homosexuality is a topic that needs to be integrated into the knowledge base of the practitioner of sexual medicine. AIM To present to the reader a summary of the current literature on homosexuality and sexual orientation and address specifically issues that pertain to the relationship sexual orientation and sexual medicine practice. MAIN OUTCOME MEASURES The information is presented in a continued medical education format, with a series of evaluation questions at the end of the activity. Methods. A review of the literature is presented and organized according to the authors' judgment of the value of the information as to provide the reader with an inclusive panorama of the issues covered. RESULTS Current concepts, debates, and need for further research are presented. CONCLUSIONS The professional of sexual medicine needs to be aware of the various topics reviewed in this article as his or her involvement in the area of sexuality can create the expectation on the part of the patients of knowingness of all aspects of human sexuality. Sexual orientation is a complex area but considerable understanding has fortunately been achieved in many issues in reference to homosexuality and heterosexuality.
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Kimura KI, Hachiya T, Koganezawa M, Tazawa T, Yamamoto D. Fruitless and doublesex coordinate to generate male-specific neurons that can initiate courtship. Neuron 2008; 59:759-69. [PMID: 18786359 DOI: 10.1016/j.neuron.2008.06.007] [Citation(s) in RCA: 228] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2007] [Revised: 05/29/2008] [Accepted: 06/02/2008] [Indexed: 11/29/2022]
Abstract
Biologists postulate that sexual dimorphism in the brain underlies gender differences in behavior, yet direct evidence for this has been sparse. We identified a male-specific, fruitless (fru)/doublesex (dsx)-coexpressing neuronal cluster, P1, in Drosophila. The artificial induction of a P1 clone in females effectively provokes male-typical behavior in such females even when the other parts of the brain are not masculinized. P1, located in the dorsal posterior brain near the mushroom body, is composed of 20 interneurons, each of which has a primary transversal neurite with extensive ramifications in the bilateral protocerebrum. P1 is fated to die in females through the action of a feminizing protein, DsxF. A masculinizing protein Fru is required in the male brain for correct positioning of the terminals of P1 neurites. Thus, the coordinated actions of two sex determination genes, dsx and fru, confer the unique ability to initiate male-typical sexual behavior on P1 neurons.
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Affiliation(s)
- Ken-Ichi Kimura
- Laboratory of Biology, Iwamizawa Campus, Hokkaido University of Education, Iwamizawa 068-8642, Japan.
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Abstract
Certain cognitive functions differ in men and women, although the anatomical and functional substrates underlying these differences remain unknown. Because neocortical activity is directly related with higher brain function, numerous studies have focused on the cerebral cortex when searching for possible structural correlates of cognitive gender differences. However, there are no studies on possible gender differences at the synaptic level. In the present work we have used stereological and correlative light and electron microscopy to show that men have a significantly higher synaptic density than women in all cortical layers of the temporal neocortex. These differences may represent a microanatomical substrate contributing to the functional gender differences in brain activity.
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