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Munley KM, Wade KL, Pradhan DS. Uncovering the seasonal brain: Liquid chromatography-tandem mass spectrometry (LC-MS/MS) as a biochemical approach for studying seasonal social behaviors. Horm Behav 2022; 142:105161. [PMID: 35339904 DOI: 10.1016/j.yhbeh.2022.105161] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 03/12/2022] [Accepted: 03/14/2022] [Indexed: 11/17/2022]
Abstract
Many animals show pronounced changes in physiology and behavior across the annual cycle, and these adaptations enable individuals to prioritize investing in the neuroendocrine mechanisms underlying reproduction and/or survival based on the time of year. While prior research has offered valuable insight into how seasonal variation in neuroendocrine processes regulates social behavior, the majority of these studies have investigated how a single hormone influences a single behavioral phenotype. Given that hormones are synthesized and metabolized via complex biochemical pathways and often act in concert to control social behavior, these approaches provide a limited view of how hormones regulate seasonal changes in behavior. In this review, we discuss how seasonal influences on hormones, the brain, and social behavior can be studied using liquid chromatography-tandem mass spectrometry (LC-MS/MS), an analytical chemistry technique that enables researchers to simultaneously quantify the concentrations of multiple hormones and the activities of their synthetic enzymes. First, we examine studies that have investigated seasonal plasticity in brain-behavior interactions, specifically by focusing on how two groups of hormones, sex steroids and nonapeptides, regulate sexual and aggressive behavior. Then, we explain the operations of LC-MS/MS, highlight studies that have used LC-MS/MS to study the neuroendocrine mechanisms underlying social behavior, both within and outside of a seasonal context, and discuss potential applications for LC-MS/MS in the field of behavioral neuroendocrinology. We propose that this cutting-edge technology will provide a more comprehensive understanding of how the multitude of hormones that comprise complex neuroendocrine networks affect seasonal variation in the brain and behavior.
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Affiliation(s)
- Kathleen M Munley
- Department of Biology and Center for the Integrative Study of Animal Behavior, Indiana University, Bloomington, IN 47405, USA.
| | - Kristina L Wade
- Department of Biological Sciences, Idaho State University, Pocatello, ID 83209, USA
| | - Devaleena S Pradhan
- Department of Biological Sciences, Idaho State University, Pocatello, ID 83209, USA
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2
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Brann DW, Lu Y, Wang J, Zhang Q, Thakkar R, Sareddy GR, Pratap UP, Tekmal RR, Vadlamudi RK. Brain-derived estrogen and neural function. Neurosci Biobehav Rev 2021; 132:793-817. [PMID: 34823913 PMCID: PMC8816863 DOI: 10.1016/j.neubiorev.2021.11.014] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 10/26/2021] [Accepted: 11/12/2021] [Indexed: 01/02/2023]
Abstract
Although classically known as an endocrine signal produced by the ovary, 17β-estradiol (E2) is also a neurosteroid produced in neurons and astrocytes in the brain of many different species. In this review, we provide a comprehensive overview of the localization, regulation, sex differences, and physiological/pathological roles of brain-derived E2 (BDE2). Much of what we know regarding the functional roles of BDE2 has come from studies using specific inhibitors of the E2 synthesis enzyme, aromatase, as well as the recent development of conditional forebrain neuron-specific and astrocyte-specific aromatase knockout mouse models. The evidence from these studies support a critical role for neuron-derived E2 (NDE2) in the regulation of synaptic plasticity, memory, socio-sexual behavior, sexual differentiation, reproduction, injury-induced reactive gliosis, and neuroprotection. Furthermore, we review evidence that astrocyte-derived E2 (ADE2) is induced following brain injury/ischemia, and plays a key role in reactive gliosis, neuroprotection, and cognitive preservation. Finally, we conclude by discussing the key controversies and challenges in this area, as well as potential future directions for the field.
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Affiliation(s)
- Darrell W Brann
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Augusta, GA, 30912, USA.
| | - Yujiao Lu
- Department of Neurosurgery, Medical College of Georgia, Augusta University, Augusta, GA, 30912, USA
| | - Jing Wang
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Augusta, GA, 30912, USA
| | - Quanguang Zhang
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Augusta, GA, 30912, USA
| | - Roshni Thakkar
- Department of Neurology, Miller School of Medicine, University of Miami, Miami, FL, 33136, USA
| | - Gangadhara R Sareddy
- Department of Obstetrics and Gynecology, University of Texas Health, San Antoio TX, 78229, USA
| | - Uday P Pratap
- Department of Obstetrics and Gynecology, University of Texas Health, San Antoio TX, 78229, USA
| | - Rajeshwar R Tekmal
- Department of Obstetrics and Gynecology, University of Texas Health, San Antoio TX, 78229, USA
| | - Ratna K Vadlamudi
- Department of Obstetrics and Gynecology, University of Texas Health, San Antoio TX, 78229, USA; Audie L. Murphy Division, South Texas Veterans Health Care System, San Antonio, TX, 78229, USA.
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3
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Loveland JL, Giraldo-Deck LM, Lank DB, Goymann W, Gahr M, Küpper C. Functional differences in the hypothalamic-pituitary-gonadal axis are associated with alternative reproductive tactics based on an inversion polymorphism. Horm Behav 2021; 127:104877. [PMID: 33186586 DOI: 10.1016/j.yhbeh.2020.104877] [Citation(s) in RCA: 6] [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: 07/20/2020] [Revised: 10/12/2020] [Accepted: 10/13/2020] [Indexed: 01/01/2023]
Abstract
The evolution of social behavior depends on genetic changes, yet, how genomic variation manifests itself in behavioral diversity is still largely unresolved. Chromosomal inversions can play a pivotal role in producing distinct behavioral phenotypes, in particular, when inversion genes are functionally associated with hormone synthesis and signaling. Male ruffs exhibit alternative reproductive tactics (ARTs) with an autosomal inversion determining two alternative morphs with clear behavioral and hormonal differences from the ancestral morph. We investigated hormonal and transcriptomic differences in the pituitary and gonads. Using a GnRH challenge, we found that the ability to synthesize testosterone in inversion carriers is severely constrained, whereas the synthesis of androstenedione, a testosterone precursor, is not. Inversion morphs were able to produce a transient increase in androstenedione following the GnRH injection, supporting the view that pituitary sensitivity to GnRH is comparable to that of the ancestral morph. We then performed gene expression analyses in a second set of untreated birds and found no evidence of alterations to pituitary sensitivity, gonadotropin production or gonad sensitivity to luteinizing hormone or follicle-stimulating hormone across morphs. Inversion morphs also showed reduced progesterone receptor expression in the pituitary. Strikingly, in the gonads, inversion morphs over-expressed STAR, a gene that is located outside of the inversion and responsible for providing the cholesterol substrate required for the synthesis of sex hormones. In conclusion, our results suggest that the gonads determine morph-specific differences in hormonal regulation.
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MESH Headings
- Androstenedione/metabolism
- Animals
- Charadriiformes/genetics
- Charadriiformes/physiology
- Follicle Stimulating Hormone, beta Subunit/genetics
- Follicle Stimulating Hormone, beta Subunit/metabolism
- Gene Expression/drug effects
- Gonadal Steroid Hormones/biosynthesis
- Gonadotropin-Releasing Hormone/pharmacology
- Gonads/drug effects
- Gonads/metabolism
- Gonads/physiology
- Hypothalamo-Hypophyseal System/drug effects
- Hypothalamo-Hypophyseal System/metabolism
- Hypothalamo-Hypophyseal System/physiology
- Male
- Pituitary Gland/drug effects
- Pituitary Gland/metabolism
- Polymorphism, Genetic
- Receptors, FSH/genetics
- Receptors, FSH/metabolism
- Receptors, LH/genetics
- Receptors, LH/metabolism
- Receptors, LHRH/genetics
- Receptors, LHRH/metabolism
- Reproduction/drug effects
- Reproduction/genetics
- Sequence Inversion
- Sexual Behavior, Animal/drug effects
- Sexual Behavior, Animal/physiology
- Signal Transduction/drug effects
- Signal Transduction/genetics
- Testosterone/metabolism
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Affiliation(s)
- J L Loveland
- Behavioural Genetics and Evolutionary Ecology Research Group, Max Planck Institute for Ornithology, Seewiesen, Germany.
| | - L M Giraldo-Deck
- Behavioural Genetics and Evolutionary Ecology Research Group, Max Planck Institute for Ornithology, Seewiesen, Germany
| | - D B Lank
- Department of Biological Sciences, Simon Fraser University, Burnaby, Canada
| | - W Goymann
- Department of Behavioural Neurobiology, Max Planck Institute for Ornithology, Seewiesen, Germany
| | - M Gahr
- Department of Behavioural Neurobiology, Max Planck Institute for Ornithology, Seewiesen, Germany
| | - C Küpper
- Behavioural Genetics and Evolutionary Ecology Research Group, Max Planck Institute for Ornithology, Seewiesen, Germany
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4
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Simkins JW, Joseph AE, Bonier F, Benowitz-Fredericks ZM. Prenatal aromatase inhibition alters postnatal immunity in domestic chickens (Gallus gallus). Gen Comp Endocrinol 2020; 294:113497. [PMID: 32360542 DOI: 10.1016/j.ygcen.2020.113497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Revised: 04/19/2020] [Accepted: 04/27/2020] [Indexed: 10/24/2022]
Abstract
In birds, exposure to exogenous testosterone during embryonic development can suppress measures of immune function; however, it is unclear whether these effects are due to direct or indirect action via aromatization. Estradiol (E2) is synthesized from testosterone by the enzyme aromatase, and this conversion is a necessary step in many signaling pathways that are ostensibly testosterone-dependent. Many lines of evidence in mammals indicate that E2 can affect immune function. We tested the hypothesis that some of the immunomodulatory effects observed in response to in ovo testosterone exposure in birds are mediated by conversion to E2 by aromatase, by using fadrozole to inhibit aromatization of endogenous testosterone during a crucial period of embryonic immune system development in domestic chickens (Gallus gallus). We then measured total IgY antibody count, response to PHA challenge, mass of thymus and bursa of Fabricius, and plasma testosterone post-hatch on days 3 and 18. Because testosterone has a reputation for immunosuppression, we predicted that if modulation of an immune measure by testosterone is dependent on aromatization, then inhibition of estrogen production by fadrozole treatment would lead to elevated measures of that parameter. Conversely, if testosterone inhibits an immune measure directly, then fadrozole treatment would likely not alter that parameter. Fadrozole treatment reduced circulating E2 in female embryos, but had no effect on males or on testosterone in either sex. Fadrozole-treated chicks had decreased day 3 plasma IgY antibody titers and a strong trend towards increased day 18 thymic mass. Furthermore, fadrozole treatment generated a positive relationship between testosterone and thymic mass in males, and tended to increase day 18 IgY levels for a given bursal mass in females. There was no effect on PHA response, bursal mass, or plasma testosterone at either age post-hatch. The alteration of several indicators of immune function in fadrozole-treated chicks implicates aromatization as a relevant pathway through which developmental exposure to testosterone can affect immunity in birds.
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Affiliation(s)
- J W Simkins
- Bucknell University, Department of Biology, 1 Dent Drive, Lewisburg, PA, USA.
| | - A E Joseph
- Bucknell University, Department of Biology, 1 Dent Drive, Lewisburg, PA, USA.
| | - F Bonier
- Queen's University, Department of Biology, 116 Barrie Street, Kingston, ON K7L 3N6, Canada.
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5
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Krohmer RW. Courtship in the male red‐sided garter snake is dependent on neural aromatase activity during winter dormancy. JOURNAL OF EXPERIMENTAL ZOOLOGY PART 2020; 333:275-283. [DOI: 10.1002/jez.2345] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 01/02/2020] [Accepted: 01/03/2020] [Indexed: 12/22/2022]
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Balthazart J. New concepts in the study of the sexual differentiation and activation of reproductive behavior, a personal view. Front Neuroendocrinol 2019; 55:100785. [PMID: 31430485 PMCID: PMC6858558 DOI: 10.1016/j.yfrne.2019.100785] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2019] [Revised: 08/13/2019] [Accepted: 08/16/2019] [Indexed: 01/09/2023]
Abstract
Since the beginning of this century, research methods in neuroendocrinology enjoyed extensive refinements and innovation. These advances allowed collection of huge amounts of new data and the development of new ideas but have not led to this point, with a few exceptions, to the development of new conceptual advances. Conceptual advances that took place largely resulted from the ingenious insights of several investigators. I summarize here some of these new ideas as they relate to the sexual differentiation and activation by sex steroids of reproductive behaviors and I discuss how our research contributed to the general picture. This selective review clearly demonstrates the importance of conceptual changes that have taken place in this field since beginning of the 21st century. The recent technological advances suggest that our understanding of hormones, brain and behavior relationships will continue to improve in a very fundamental manner over the coming years.
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Rosenfeld CS. Effects of Phytoestrogens on the Developing Brain, Gut Microbiota, and Risk for Neurobehavioral Disorders. Front Nutr 2019; 6:142. [PMID: 31555657 PMCID: PMC6727358 DOI: 10.3389/fnut.2019.00142] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2019] [Accepted: 08/14/2019] [Indexed: 01/11/2023] Open
Abstract
Many pregnant and nursing women consume high amounts of soy and other plant products that contain phytoestrogens, such as genistein (GEN) and daidzein. Infants may also be provided soy based formulas. With their ability to bind and activate estrogen receptors (ESR) in the brain, such compounds can disrupt normal brain programming and lead to later neurobehavioral disruptions. However, other studies suggest that maternal consumption of soy and soy based formulas containing such phytoestrogens might lead to beneficial behavioral effects. Select gut microbes might also convert daidzein and to a lesser extent genistein to even more potent forms, e.g., equol derivatives. Thus, infant exposure to phytoestrogens may result in contrasting effects dependent upon the gut flora. It is also becoming apparent that consumption or exposure to these xenoestrogens may lead to gut dysbiosis. Phytoestrogen-induced changes in gut bacteria might in turn affect the brain through various mechanisms. This review will consider the evidence to date in rodent and other animal models and human epidemiological data as to whether developmental exposure to phytoestrogens, in particular genistein and daidzein, adversely or beneficially impact offspring neurobehavioral programming. Consideration will be given to potential mechanisms by which such compounds might affect neurobehavioral responses. A better understanding of effects perinatal exposure to phytoestrogen can exert on brain programming will permit pregnant women and those seeking to become pregnant to make better-educated choices. If phytoestrogen-induced gut dysbiosis contributes to neurobehavioral disruptions, remediation strategies may be designed to prevent such gut microbiota alterations and thereby improve neurobehavioral outcomes.
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Affiliation(s)
- Cheryl S. Rosenfeld
- Bond Life Sciences Center, University of Missouri, Columbia, MO, United States
- MU Informatics Institute, University of Missouri, Columbia, MO, United States
- Thompson Center for Autism and Neurobehavioral Disorders, University of Missouri, Columbia, MO, United States
- Biomedical Sciences, University of Missouri, Columbia, MO, United States
- Genetics Area Program, University of Missouri, Columbia, MO, United States
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8
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Riters LV, Kelm-Nelson CA, Spool JA. Why Do Birds Flock? A Role for Opioids in the Reinforcement of Gregarious Social Interactions. Front Physiol 2019; 10:421. [PMID: 31031641 PMCID: PMC6473117 DOI: 10.3389/fphys.2019.00421] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Accepted: 03/27/2019] [Indexed: 12/16/2022] Open
Abstract
The formation of social groups provides safety and opportunities for individuals to develop and practice important social skills. However, joining a social group does not result in any form of obvious, immediate reinforcement (e.g., it does not result in immediate copulation or a food reward), and individuals often remain in social groups despite agonistic responses from conspecifics. Much is known about neural and endocrine mechanisms underlying the motivation to perform mate- or offspring-directed behaviors. In contrast, relatively little is known about mechanisms underlying affiliative behaviors outside of these primary reproductive contexts. Studies on flocking behavior in songbirds are beginning to fill this knowledge gap. Here we review behavioral evidence that supports the hypothesis that non-sexual affiliative, flocking behaviors are both (1) rewarded by positive social interactions with conspecifics, and (2) reinforced because affiliative contact reduces a negative affective state caused by social isolation. We provide evidence from studies in European starlings, Sturnus vulgaris, that mu opioid receptors in the medial preoptic nucleus (mPOA) play a central role in both reward and the reduction of a negative affective state induced by social interactions in flocks, and discuss potential roles for nonapeptide/opioid interactions and steroid hormones. Finally, we develop the case that non-sexual affiliative social behaviors may be modified by two complementary output pathways from mPOA, with a projection from mPOA to the periaqueductal gray integrating information during social interactions that reduces negative affect and a projection from mPOA to the ventral tegmental area integrating information leading to social approach and reward.
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Affiliation(s)
- Lauren V. Riters
- Department of Integrative Biology, University of Wisconsin–Madison, Madison, WI, United States
| | - Cynthia A. Kelm-Nelson
- Division of Otolaryngology-Head & Neck Surgery, Department of Surgery, University of Wisconsin–Madison, Madison, WI, United States
| | - Jeremy A. Spool
- Department of Psychological and Brain Sciences, University of Massachusetts Amherst, Amherst, MA, United States
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9
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Liere P, Cornil CA, de Bournonville MP, Pianos A, Keller M, Schumacher M, Balthazart J. Steroid profiles in quail brain and serum: Sex and regional differences and effects of castration with steroid replacement. J Neuroendocrinol 2019; 31:e12681. [PMID: 30585662 PMCID: PMC6412023 DOI: 10.1111/jne.12681] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 12/21/2018] [Accepted: 12/21/2018] [Indexed: 02/02/2023]
Abstract
Both systemic and local production contribute to the concentration of steroids measured in the brain. This idea was originally based on rodent studies and was later extended to other species, including humans and birds. In quail, a widely used model in behavioural neuroendocrinology, it was demonstrated that all enzymes needed to produce sex steroids from cholesterol are expressed and active in the brain, although the actual concentrations of steroids produced were never investigated. We carried out a steroid profiling in multiple brain regions and serum of sexually mature male and female quail by gas chromatography coupled with mass spectrometry. The concentrations of some steroids (eg, corticosterone, progesterone and testosterone) were in equilibrium between the brain and periphery, whereas other steroids (eg, pregnenolone (PREG), 5α/β-dihydroprogesterone and oestrogens) were more concentrated in the brain. In the brain regions investigated, PREG sulphate, progesterone and oestrogen concentrations were higher in the hypothalamus-preoptic area. Progesterone and its metabolites were more concentrated in the female than the male brain, whereas testosterone, its metabolites and dehydroepiandrosterone were more concentrated in males, suggesting that sex steroids present in quail brain mainly depend on their specific steroidogenic pathways in the ovaries and testes. However, the results of castration experiments suggested that sex steroids could also be produced in the brain independently of the peripheral source. Treatment with testosterone or oestradiol restored the concentrations of most androgens or oestrogens, respectively, although penetration of oestradiol in the brain appeared to be more limited. These studies illustrate the complex interaction between local brain synthesis and the supply from the periphery for the steroids present in the brain that are either directly active or represent the substrate of centrally located enzymes.
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Affiliation(s)
- Philippe Liere
- U1195 INSERM, University Paris Sud and University Paris Saclay, 80 rue du Général Leclerc, 94276 Le Kremlin-Bicêtre Cédex, France
| | - Charlotte A. Cornil
- University of Liège, GIGA Neurosciences, 1 Avenue de l’Hôpital (Bat. B36), 4000 Liège, Belgium
| | | | - Antoine Pianos
- U1195 INSERM, University Paris Sud and University Paris Saclay, 80 rue du Général Leclerc, 94276 Le Kremlin-Bicêtre Cédex, France
| | - Matthieu Keller
- Laboratoire de Physiologie de la Reproduction et des Comportements, UMR 7247 INRA/CNRS/Université de Tours, Nouzilly, France
| | - Michael Schumacher
- U1195 INSERM, University Paris Sud and University Paris Saclay, 80 rue du Général Leclerc, 94276 Le Kremlin-Bicêtre Cédex, France
| | - Jacques Balthazart
- University of Liège, GIGA Neurosciences, 1 Avenue de l’Hôpital (Bat. B36), 4000 Liège, Belgium
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10
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de Bournonville MP, Vandries LM, Ball GF, Balthazart J, Cornil CA. Site-specific effects of aromatase inhibition on the activation of male sexual behavior in male Japanese quail (Coturnix japonica). Horm Behav 2019; 108:42-49. [PMID: 30605622 PMCID: PMC6377315 DOI: 10.1016/j.yhbeh.2018.12.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Revised: 12/21/2018] [Accepted: 12/30/2018] [Indexed: 12/14/2022]
Abstract
Aromatization within the medial preoptic nucleus (POM) is essential for the expression of male copulatory behavior in Japanese quail. However, several nuclei within the social behavior network (SBN) also express aromatase. Whether aromatase in these loci participates in the behavioral activation is not known. Castrated male Japanese quail were implanted with 2 subcutaneous Silastic capsules filled with crystalline testosterone and with bilateral stereotaxic implants filled with the aromatase inhibitor Vorozole targeting the POM, the bed nucleus of the stria terminalis (BST) or the ventromedial nucleus of the hypothalamus (VMN). Control animals were implanted with testosterone and empty bilateral stereotaxic implants. Starting 2 days after the surgery, subjects were tested for the expression of consummatory sexual behavior (CSB) every other day for a total of 10 tests. They were also tested once for appetitive sexual behavior (ASB) as measured by the rhythmic cloacal sphincter movements displayed in response to the visual presentation of a female. CSB was drastically reduced when the Vorozole implants were localized in the POM, but not in the BST nor in the VMN. Birds with implants in the BST took longer to show CSB in the first 6 tests than controls, suggesting a role of the BST in the acquisition of the full copulatory ability. ASB was not significantly affected by aromatase blockade in any region. These data confirm the key role played by the POM in the control of male sexual behavior and suggest a minor role for aromatization in the BST or VMN.
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Affiliation(s)
| | | | - Gregory F Ball
- Department of Psychology, University of Maryland, College Park, MD, United States of America
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11
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Sexual dimorphism in brain transcriptomes of Amami spiny rats (Tokudaia osimensis): a rodent species where males lack the Y chromosome. BMC Genomics 2019; 20:87. [PMID: 30683046 PMCID: PMC6347839 DOI: 10.1186/s12864-019-5426-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Accepted: 01/02/2019] [Indexed: 02/06/2023] Open
Abstract
Background Brain sexual differentiation is sculpted by precise coordination of steroid hormones during development. Programming of several brain regions in males depends upon aromatase conversion of testosterone to estrogen. However, it is not clear the direct contribution that Y chromosome associated genes, especially sex-determining region Y (Sry), might exert on brain sexual differentiation in therian mammals. Two species of spiny rats: Amami spiny rat (Tokudaia osimensis) and Tokunoshima spiny rat (T. tokunoshimensis) lack a Y chromosome/Sry, and these individuals possess an XO chromosome system in both sexes. Both Tokudaia species are highly endangered. To assess the neural transcriptome profile in male and female Amami spiny rats, RNA was isolated from brain samples of adult male and female spiny rats that had died accidentally and used for RNAseq analyses. Results RNAseq analyses confirmed that several genes and individual transcripts were differentially expressed between males and females. In males, seminal vesicle secretory protein 5 (Svs5) and cytochrome P450 1B1 (Cyp1b1) genes were significantly elevated compared to females, whereas serine (or cysteine) peptidase inhibitor, clade A, member 3 N (Serpina3n) was upregulated in females. Many individual transcripts elevated in males included those encoding for zinc finger proteins, e.g. zinc finger protein X-linked (Zfx). Conclusions This method successfully identified several genes and transcripts that showed expression differences in the brain of adult male and female Amami spiny rat. The functional significance of these findings, especially differential expression of transcripts encoding zinc finger proteins, in this unusual rodent species remains to be determined. Electronic supplementary material The online version of this article (10.1186/s12864-019-5426-6) contains supplementary material, which is available to authorized users.
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Cornil CA, Ball GF, Balthazart J. Differential control of appetitive and consummatory sexual behavior by neuroestrogens in male quail. Horm Behav 2018; 104:15-31. [PMID: 29452074 PMCID: PMC6103895 DOI: 10.1016/j.yhbeh.2018.02.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 02/05/2018] [Accepted: 02/09/2018] [Indexed: 11/17/2022]
Abstract
Contribution to Special Issue on Fast effects of steroids. Estrogens exert pleiotropic effects on multiple physiological and behavioral traits including sexual behavior. These effects are classically mediated via binding to nuclear receptors and subsequent regulation of target gene transcription. Estrogens also affect neuronal activity and cell-signaling pathways via faster, membrane-initiated events. Although the distinction between appetitive and consummatory aspects of sexual behavior has been criticized, this distinction remains valuable in that it facilitates the causal analysis of certain behavioral systems. Effects of neuroestrogens produced by neuronal aromatization of testosterone on copulatory performance (consummatory aspect) and on sexual motivation (appetitive aspect) are described in male quail. The central administration of estradiol rapidly increases expression of sexual motivation, as assessed by two measures of sexual motivation produced in response to the visual presentation of a female but not sexual performance in male Japanese quail. This effect is mimicked by membrane-impermeable analogs of estradiol, indicating that it is initiated at the cell membrane. Conversely, blocking the action of estrogens or their synthesis by a single intracerebroventricular injection of estrogen receptor antagonists or aromatase inhibitors, respectively, decreases sexual motivation within minutes without affecting performance. The same steroid has thus evolved complementary mechanisms to regulate different behavioral components (motivation vs. performance) in distinct temporal domains (long- vs. short-term) so that diverse reproductive activities can be properly coordinated. Changes in preoptic aromatase activity and estradiol as well as glutamate concentrations are observed during or immediately after copulation. The interaction between these neuroendocrine/neurochemical changes and their functional significance is discussed.
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Affiliation(s)
| | - Gregory F Ball
- Department of Psychology, University of Maryland, College Park, MD 20742, United States
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Diotel N, Charlier TD, Lefebvre d'Hellencourt C, Couret D, Trudeau VL, Nicolau JC, Meilhac O, Kah O, Pellegrini E. Steroid Transport, Local Synthesis, and Signaling within the Brain: Roles in Neurogenesis, Neuroprotection, and Sexual Behaviors. Front Neurosci 2018; 12:84. [PMID: 29515356 PMCID: PMC5826223 DOI: 10.3389/fnins.2018.00084] [Citation(s) in RCA: 96] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 02/02/2018] [Indexed: 01/18/2023] Open
Abstract
Sex steroid hormones are synthesized from cholesterol and exert pleiotropic effects notably in the central nervous system. Pioneering studies from Baulieu and colleagues have suggested that steroids are also locally-synthesized in the brain. Such steroids, called neurosteroids, can rapidly modulate neuronal excitability and functions, brain plasticity, and behavior. Accumulating data obtained on a wide variety of species demonstrate that neurosteroidogenesis is an evolutionary conserved feature across fish, birds, and mammals. In this review, we will first document neurosteroidogenesis and steroid signaling for estrogens, progestagens, and androgens in the brain of teleost fish, birds, and mammals. We will next consider the effects of sex steroids in homeostatic and regenerative neurogenesis, in neuroprotection, and in sexual behaviors. In a last part, we will discuss the transport of steroids and lipoproteins from the periphery within the brain (and vice-versa) and document their effects on the blood-brain barrier (BBB) permeability and on neuroprotection. We will emphasize the potential interaction between lipoproteins and sex steroids, addressing the beneficial effects of steroids and lipoproteins, particularly HDL-cholesterol, against the breakdown of the BBB reported to occur during brain ischemic stroke. We will consequently highlight the potential anti-inflammatory, anti-oxidant, and neuroprotective properties of sex steroid and lipoproteins, these latest improving cholesterol and steroid ester transport within the brain after insults.
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Affiliation(s)
- Nicolas Diotel
- Université de La Réunion, Institut National de la Santé et de la Recherche Médicale, UMR 1188, Diabète athérothrombose Thérapies Réunion Océan Indien, Saint-Denis de La Réunion, France
| | - Thierry D. Charlier
- Univ Rennes, Inserm, EHESP, Irset (Institut de recherche en santé, environnement et travail) - UMR_S 1085, Rennes, France
| | - Christian Lefebvre d'Hellencourt
- Université de La Réunion, Institut National de la Santé et de la Recherche Médicale, UMR 1188, Diabète athérothrombose Thérapies Réunion Océan Indien, Saint-Denis de La Réunion, France
| | - David Couret
- Université de La Réunion, Institut National de la Santé et de la Recherche Médicale, UMR 1188, Diabète athérothrombose Thérapies Réunion Océan Indien, Saint-Denis de La Réunion, France
- CHU de La Réunion, Saint-Denis, France
| | | | - Joel C. Nicolau
- Univ Rennes, Inserm, EHESP, Irset (Institut de recherche en santé, environnement et travail) - UMR_S 1085, Rennes, France
| | - Olivier Meilhac
- Université de La Réunion, Institut National de la Santé et de la Recherche Médicale, UMR 1188, Diabète athérothrombose Thérapies Réunion Océan Indien, Saint-Denis de La Réunion, France
- CHU de La Réunion, Saint-Denis, France
| | - Olivier Kah
- Univ Rennes, Inserm, EHESP, Irset (Institut de recherche en santé, environnement et travail) - UMR_S 1085, Rennes, France
| | - Elisabeth Pellegrini
- Univ Rennes, Inserm, EHESP, Irset (Institut de recherche en santé, environnement et travail) - UMR_S 1085, Rennes, France
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Rosenfeld CS, Shay DA, Vieira-Potter VJ. Cognitive Effects of Aromatase and Possible Role in Memory Disorders. Front Endocrinol (Lausanne) 2018; 9:610. [PMID: 30386297 PMCID: PMC6199361 DOI: 10.3389/fendo.2018.00610] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 09/26/2018] [Indexed: 12/14/2022] Open
Abstract
Diverse cognitive functions in many vertebrate species are influenced by local conversion of androgens to 17β-estradiol (E2) by aromatase. This enzyme is highly expressed in various brain regions across species, with some inter-species variation in terms of regional brain expression. Since women with breast cancer and men and women with other disorders are often treated with aromatase inhibitors (AI), these populations might be especially vulnerable to cognitive deficits due to low neuroE2 synthesis, i.e., synthesis of E2 directly within the brain. Animal models have been useful in deciphering aromatase effects on cognitive functions. Consequences of AI administration at various life cycle stages have been assessed on auditory, song processing, and spatial memory in birds and various aspects of cognition in rodent models. Additionally, cognitive deficits have been described in aromatase knockout (ArKO) mice that systemically lack this gene throughout their lifespan. This review will consider evidence to date that AI treatment in male and female rodent models, birds, and humans results in cognitive impairments. How brain aromatase regulates cognitive function throughout the lifespan, and gaps in current knowledge will be considered, along with future directions to better define how aromatase might guide learning and memory from early development through the geriatric period. Better understanding the importance of E2 synthesis on neurobehavioral responses at various ages will likely aid in the discovery of therapeutic strategies to prevent potential cognitive deficits, including Alzheimer's Disease, in individuals treated with AI or those possessing CYP19 gene polymorphisms, as well as cognitive effects of normal aging that may be related to changes in brain aromatase activity.
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Affiliation(s)
- Cheryl S. Rosenfeld
- Bond Life Sciences Center, University of Missouri, Columbia, MO, United States
- Thompson Center for Autism and Neurobehavioral Disorders, University of Missouri, Columbia, MO, United States
- Biomedical Sciences, University of Missouri, Columbia, MO, United States
- *Correspondence: Cheryl S. Rosenfeld
| | - Dusti A. Shay
- Nutrition and Exercise Physiology, University of Missouri, Columbia, MO, United States
| | - Victoria J. Vieira-Potter
- Nutrition and Exercise Physiology, University of Missouri, Columbia, MO, United States
- Victoria J. Vieira-Potter
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15
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Rosenfeld CS. Brain Sexual Differentiation and Requirement of SRY: Why or Why Not? Front Neurosci 2017; 11:632. [PMID: 29200993 PMCID: PMC5696354 DOI: 10.3389/fnins.2017.00632] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Accepted: 10/30/2017] [Indexed: 12/22/2022] Open
Abstract
Brain sexual differentiation is orchestrated by precise coordination of sex steroid hormones. In some species, programming of select male brain regions is dependent upon aromatization of testosterone to estrogen. In mammals, these hormones surge during the organizational and activational periods that occur during perinatal development and adulthood, respectively. In various fish and reptiles, incubation temperature during a critical embryonic period results in male or female sexual differentiation, but this can be overridden in males by early exposure to estrogenic chemicals. Testes development in mammals requires a Y chromosome and testis determining gene SRY (in humans)/Sry (all other therian mammals), although there are notable exceptions. Two species of spiny rats: Amami spiny rat (Tokudaia osimensis) and Tokunoshima spiny rat (Tokudaia tokunoshimensis) and two species of mole voles (Ellobius lutescens and Ellobius tancrei), lack a Y chromosome/Sry and possess an XO chromosome system in both sexes. Such rodent species, prototherians (monotremes, who also lack Sry), and fish and reptile species that demonstrate temperature sex determination (TSD) seemingly call into question the requirement of Sry for brain sexual differentiation. This review will consider brain regions expressing SRY/Sry in humans and rodents, respectively, and potential roles of SRY/Sry in the brain will be discussed. The evidence from various taxa disputing the requirement of Sry for brain sexual differentiation in mammals (therians and prototherians) and certain fish and reptilian species will be examined. A comparative approach to address this question may elucidate other genes, pathways, and epigenetic modifications stimulating brain sexual differentiation in vertebrate species, including humans.
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Affiliation(s)
- Cheryl S Rosenfeld
- Bond Life Sciences Center, University of Missouri, Columbia, MO, United States.,Biomedical Sciences, University of Missouri, Columbia, MO, United States.,Thompson Center for Autism and Neurobehavioral Disorders, University of Missouri, Columbia, MO, United States.,Genetics Area Program, University of Missouri, Columbia, MO, United States
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16
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Balthazart J. Steroid metabolism in the brain: From bird watching to molecular biology, a personal journey. Horm Behav 2017; 93:137-150. [PMID: 28576650 PMCID: PMC5544559 DOI: 10.1016/j.yhbeh.2017.05.017] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Revised: 05/15/2017] [Accepted: 05/28/2017] [Indexed: 11/19/2022]
Abstract
Since Arnold Adolph Berthold established in 1849 the critical role of the testes in the activation of male sexual behavior, intensive research has identified many sophisticated neurochemical and molecular mechanisms mediating this action. Studies in Japanese quail demonstrated the critical role of testosterone action and of testosterone aromatization in the sexually dimorphic medial preoptic nucleus in the activation of male copulatory behavior. The development of an immunohistochemical visualization of brain aromatase in quail then allowed further refinement in the localization of the sites of neuroestrogens production. Testosterone aromatization is required for the activation of both appetitive and consummatory aspects of male sexual behavior. Brain aromatase activity is modulated by steroid-induced changes in the transcription of the corresponding gene but also more rapidly by phosphorylation processes. Sexual interactions with a female also rapidly regulate brain aromatase activity in an anatomically specific manner presumably via the release and action of endogenous glutamate. These rapid changes in estrogen production modulate sexual behavior and in particular its motivational component with latencies ranging between 15 and 30min. Brain estrogens seem to act in a manner akin to a neurotransmitter or at least a neuromodulator. More recently, assays of brain estradiol concentrations in micropunched samples or in dialysis samples obtained from behaviorally active males suggested that aromatase activity measured ex vivo might not be an accurate proxy to the rapid changes in local neuroestrogens production and concentrations. Studies of brain testosterone metabolism are thus not over and will keep scientists busy for a little longer. Elsevier SBN Keynote Address, Montreal.
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Affiliation(s)
- Jacques Balthazart
- GIGA Neurosciences, University of Liege, 15 Avenue Hippocrate, B-4000 Liège, Belgium.
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17
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Di Giorgio E, Loveland JL, Mayer U, Rosa-Salva O, Versace E, Vallortigara G. Filial responses as predisposed and learned preferences: Early attachment in chicks and babies. Behav Brain Res 2017; 325:90-104. [DOI: 10.1016/j.bbr.2016.09.018] [Citation(s) in RCA: 85] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 09/06/2016] [Accepted: 09/08/2016] [Indexed: 12/25/2022]
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18
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Hormonal Responses to a Potential Mate in Male Birds. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 1001:137-149. [DOI: 10.1007/978-981-10-3975-1_9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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19
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Rosenfeld CS, Denslow ND, Orlando EF, Gutierrez-Villagomez JM, Trudeau VL. Neuroendocrine disruption of organizational and activational hormone programming in poikilothermic vertebrates. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART B, CRITICAL REVIEWS 2017; 20:276-304. [PMID: 28895797 PMCID: PMC6174081 DOI: 10.1080/10937404.2017.1370083] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
In vertebrates, sexual differentiation of the reproductive system and brain is tightly orchestrated by organizational and activational effects of endogenous hormones. In mammals and birds, the organizational period is typified by a surge of sex hormones during differentiation of specific neural circuits; whereas activational effects are dependent upon later increases in these same hormones at sexual maturation. Depending on the reproductive organ or brain region, initial programming events may be modulated by androgens or require conversion of androgens to estrogens. The prevailing notion based upon findings in mammalian models is that male brain is sculpted to undergo masculinization and defeminization. In absence of these responses, the female brain develops. While timing of organizational and activational events vary across taxa, there are shared features. Further, exposure of different animal models to environmental chemicals such as xenoestrogens such as bisphenol A-BPA and ethinylestradiol-EE2, gestagens, and thyroid hormone disruptors, broadly classified as neuroendocrine disrupting chemicals (NED), during these critical periods may result in similar alterations in brain structure, function, and consequently, behaviors. Organizational effects of neuroendocrine systems in mammals and birds appear to be permanent, whereas teleost fish neuroendocrine systems exhibit plasticity. While there are fewer NED studies in amphibians and reptiles, data suggest that NED disrupt normal organizational-activational effects of endogenous hormones, although it remains to be determined if these disturbances are reversible. The aim of this review is to examine how various environmental chemicals may interrupt normal organizational and activational events in poikilothermic vertebrates. By altering such processes, these chemicals may affect reproductive health of an animal and result in compromised populations and ecosystem-level effects.
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Affiliation(s)
- Cheryl S. Rosenfeld
- Department of Biomedical Sciences, University of Missouri, Columbia, MO, USA
- Thompson Center for Autism and Neurobehavioral Disorders, Columbia, MO, USA
- Bond Life Sciences Center, University of Missouri, Columbia, MO, USA
| | - Nancy D. Denslow
- Department of Physiological Sciences, University of Florida, Gainesville, FL, USA
- Center for Environmental and Human Toxicology, University of Florida, Gainesville, FL, USA
| | - Edward F. Orlando
- Department of Animal and Avian Sciences, University of Maryland, College Park, MD, USA
| | | | - Vance L. Trudeau
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
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20
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First exposure to an alive conspecific activates septal and amygdaloid nuclei in visually-naïve domestic chicks (Gallus gallus). Behav Brain Res 2017; 317:71-81. [DOI: 10.1016/j.bbr.2016.09.031] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2016] [Revised: 09/05/2016] [Accepted: 09/11/2016] [Indexed: 12/29/2022]
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Abstract
Complex vocal signals, such as birdsong, contain acoustic elements that differ in both order and duration. These elements may convey socially relevant meaning, both independently and through their interactions, yet statistical methods that combine order and duration data to extract meaning have not, to our knowledge, been fully developed. Here we design novel semi-Markov methods, Bayesian estimation and classification trees to extract order and duration information from behavioural sequences and apply these methods to songs produced by male European starlings, Sturnus vulgaris, in two social contexts in which the function of song differs: a spring (breeding) and autumn (nonbreeding) context. Additionally, previous data indicate that damage to the medial preoptic nucleus (POM), a brain area known to regulate male sexually motivated behaviour, affects structural aspects of starling song such that males in a sexually relevant context (i.e. spring) sing shorter songs than appropriate for this context. We further test the utility of our statistical approach by comparing attributes of song structure in POM-lesioned males to song produced by control spring and autumn males. Spring and autumn songs were statistically separable based on the duration and order of phrase types. Males produced more structurally complex aspects of song in spring than in autumn. Spring song was also longer and more stereotyped than autumn song, both attributes used by females to select mates. Songs produced by POM-lesioned males in some cases fell between measures of spring and autumn songs but differed most from songs produced by autumn males. Overall, these statistical methods can effectively extract biologically meaningful information contained in many behavioural sequences given sufficient sample sizes and replication numbers.
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Affiliation(s)
- Sarah J. Alger
- Department of Biology, University of Wisconsin-Stevens Point, WI, U.S.A., Department of Zoology, University of Wisconsin-Madison, WI, U.S.A., Department of Statistics, University of Wisconsin-Madison, WI, U.S.A
| | - Bret R. Larget
- Department of Statistics, University of Wisconsin-Madison, WI, U.S.A., Department of Botany, University of Wisconsin-Madison, WI, U.S.A
| | - Lauren V. Riters
- Department of Zoology, University of Wisconsin-Madison, WI, U.S.A., Correspondence: L. V. Riters, Department of Zoology, 428 Birge Hall, 430 Lincoln Drive, University of Wisconsin-Madison, Madison, WI 53706, U.S.A. (L. V. Riters)
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22
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Abstract
Complex vocal signals, such as birdsong, contain acoustic elements that differ in both order and duration. These elements may convey socially relevant meaning, both independently and through their interactions, yet statistical methods that combine order and duration data to extract meaning have not, to our knowledge, been fully developed. Here we design novel semi-Markov methods, Bayesian estimation and classification trees to extract order and duration information from behavioural sequences and apply these methods to songs produced by male European starlings, Sturnus vulgaris, in two social contexts in which the function of song differs: a spring (breeding) and autumn (nonbreeding) context. Additionally, previous data indicate that damage to the medial preoptic nucleus (POM), a brain area known to regulate male sexually motivated behaviour, affects structural aspects of starling song such that males in a sexually relevant context (i.e. spring) sing shorter songs than appropriate for this context. We further test the utility of our statistical approach by comparing attributes of song structure in POM-lesioned males to song produced by control spring and autumn males. Spring and autumn songs were statistically separable based on the duration and order of phrase types. Males produced more structurally complex aspects of song in spring than in autumn. Spring song was also longer and more stereotyped than autumn song, both attributes used by females to select mates. Songs produced by POM-lesioned males in some cases fell between measures of spring and autumn songs but differed most from songs produced by autumn males. Overall, these statistical methods can effectively extract biologically meaningful information contained in many behavioural sequences given sufficient sample sizes and replication numbers.
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23
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Cordes MA, Stevenson SA, Driessen TM, Eisinger BE, Riters LV. Sexually-motivated song is predicted by androgen-and opioid-related gene expression in the medial preoptic nucleus of male European starlings (Sturnus vulgaris). Behav Brain Res 2015; 278:12-20. [PMID: 25264575 PMCID: PMC4559756 DOI: 10.1016/j.bbr.2014.09.029] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Revised: 09/08/2014] [Accepted: 09/15/2014] [Indexed: 12/15/2022]
Abstract
Across vertebrates, communication conveys information about an individual's motivational state, yet little is known about the neuroendocrine regulation of motivational aspects of communication. For seasonally breeding songbirds, increases in testosterone in spring stimulate high rates of sexually-motivated courtship song, though not all birds sing at high rates. It is generally assumed that testosterone or its metabolites act within the medial preoptic nucleus (POM) to stimulate the motivation to sing. In addition to androgen receptors (ARs) and testosterone, opioid neuropeptides in the POM influence sexually-motivated song production, and it has been proposed that testosterone may in part regulate song by modifying opioid systems. To gain insight into a possible role for androgen-opioid interactions in the regulation of communication we examined associations between sexually-motivated song and relative expression of ARs, mu opioid receptors (muORs), and preproenkephalin (PENK) in the POM (and other regions) of male European starlings using qPCR. Both AR and PENK expression in POM correlated positively with singing behavior, whereas muOR in POM correlated negatively with song. Furthermore, the ratio of PENK/muOR expression correlated negatively with AR expression in POM. Finally, in the ventral tegmental area (VTA), PENK expression correlated negatively with singing behavior. Results support the hypothesis that ARs may alter opioid gene expression in POM to fine-tune singing to reflect a male's motivational state. Data also suggest that bidirectional relationships may exist between opioids and ARs in POM and song, and additionally support a role for opioids in the VTA, independent of AR activity in this region.
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Affiliation(s)
- M A Cordes
- University of Wisconsin, Madison Department of Zoology, 430 Lincoln Ave., Madison, WI, USA.
| | - S A Stevenson
- University of Wisconsin, Madison Department of Zoology, 430 Lincoln Ave., Madison, WI, USA
| | - T M Driessen
- University of Wisconsin, Madison Department of Zoology, 430 Lincoln Ave., Madison, WI, USA; Washington State University, Integrated Physiology and Neuroscience Department, 1815 Ferdinand's Lane, Pullman, WA, USA
| | - B E Eisinger
- University of Wisconsin, Madison Department of Zoology, 430 Lincoln Ave., Madison, WI, USA; University of Wisconsin-Madison School of Medicine and Public Health, Waisman Center and Department of Neuroscience, 1500 Highland Ave., Madison, WI 53705, USA
| | - L V Riters
- University of Wisconsin, Madison Department of Zoology, 430 Lincoln Ave., Madison, WI, USA
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24
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Environmental Health Factors and Sexually Dimorphic Differences in Behavioral Disruptions. Curr Environ Health Rep 2014; 1:287-301. [PMID: 25705580 DOI: 10.1007/s40572-014-0027-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Mounting evidence suggests that environmental factors-in particular, those that we are exposed to during perinatal life-can dramatically shape the organism's risk for later diseases, including neurobehavioral disorders. However, depending on the environmental insult, one sex may demonstrate greater vulnerability than the other sex. Herein, we focus on two well-defined extrinsic environmental factors that lead to sexually dimorphic behavioral differences in animal models and linkage in human epidemiological studies. These include maternal or psychosocial stress (such as social stress) and exposure to endocrine-disrupting compounds (such as one of the most prevalent, bisphenol A [BPA]). In general, the evidence suggests that early environmental exposures, such as BPA and stress, lead to more pronounced behavioral deficits in males than in females, whereas female neurobehavioral patterns are more vulnerable to later in life stress. These findings highlight the importance of considering sex differences and developmental timing when examining the effects of environmental factors on later neurobehavioral outcomes.
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25
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Cordes MA, Stevenson SA, Riters LV. Status-appropriate singing behavior, testosterone and androgen receptor immunolabeling in male European starlings (Sturnus vulgaris). Horm Behav 2014; 65:329-39. [PMID: 24594286 PMCID: PMC4010097 DOI: 10.1016/j.yhbeh.2014.02.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Revised: 02/22/2014] [Accepted: 02/24/2014] [Indexed: 12/27/2022]
Abstract
Vocalizations convey information about an individual's motivational, internal, and social status. As circumstances change, individuals respond by adjusting vocal behavior accordingly. In European starlings, a male that acquires a nest site socially dominates other males and dramatically increases courtship song. Although circulating testosterone is associated with social status and vocal production it is possible that steroid receptors fine-tune status-appropriate changes in behavior. Here we explored a possible role for androgen receptors. Male starlings that acquired nest sites produced high rates of courtship song. For a subset of males this occurred even in the absence of elevated circulating testosterone. Immunolabeling for androgen receptors (ARir) was highest in the medial preoptic nucleus (POM) in males with both a nest site and elevated testosterone. For HVC, ARir was higher in dominant males with high testosterone (males that sang longer songs) than dominant males with low testosterone (males that sang shorter songs). ARir in the dorsal medial portion of the nucleus intercollicularis (DM) was elevated in males with high testosterone irrespective of dominance status. Song bout length related positively to ARir in POM, HVC and DM, and testosterone concentrations related positively to ARir in POM and DM. Results suggest that the role of testosterone in vocal behavior differs across brain regions and support the hypothesis that testosterone in POM underlies motivation, testosterone in HVC relates to song quality, and testosterone in DM stimulates vocalizations. Our data also suggest that singing may influence AR independent of testosterone and that alternative androgen-independent pathways regulate status-appropriate singing behavior.
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Affiliation(s)
- M A Cordes
- Department of Zoology, University of Wisconsin, Madison 53706, USA.
| | - S A Stevenson
- Department of Zoology, University of Wisconsin, Madison 53706, USA
| | - L V Riters
- Department of Zoology, University of Wisconsin, Madison 53706, USA
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26
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Jašarević E, Geary DC, Rosenfeld CS. Sexually selected traits: a fundamental framework for studies on behavioral epigenetics. ILAR J 2014; 53:253-69. [PMID: 23744965 DOI: 10.1093/ilar.53.3-4.253] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Emerging evidence suggests that epigenetic-based mechanisms contribute to various aspects of sex differences in brain and behavior. The major obstacle in establishing and fully understanding this linkage is identifying the traits that are most susceptible to epigenetic modification. We have proposed that sexual selection provides a conceptual framework for identifying such traits. These are traits involved in intrasexual competition for mates and intersexual choice of mating partners and generally entail a combination of male-male competition and female choice. These behaviors are programmed during early embryonic and postnatal development, particularly during the transition from the juvenile to adult periods, by exposure of the brain to steroid hormones, including estradiol and testosterone. We evaluate the evidence that endocrine-disrupting compounds, including bisphenol A, can interfere with the vital epigenetic and gene expression pathways and with the elaboration of sexually selected traits with epigenetic mechanisms presumably governing the expression of these traits. Finally, we review the evidence to suggest that these steroid hormones can induce a variety of epigenetic changes in the brain, including the extent of DNA methylation, histone protein alterations, and even alterations of noncoding RNA, and that many of the changes differ between males and females. Although much previous attention has focused on primary sex differences in reproductive behaviors, such as male mounting and female lordosis, we outline why secondary sex differences related to competition and mate choice might also trace their origins back to steroid-induced epigenetic programming in disparate regions of the brain.
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Affiliation(s)
- Eldin Jašarević
- Department of Psychological Sciences, the Interdisciplinary Neuroscience Program, and the Bond Life Sciences Center, University of Missouri, Columbia 65211, USA
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27
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Differential effects of global versus local testosterone on singing behavior and its underlying neural substrate. Proc Natl Acad Sci U S A 2013; 110:19573-8. [PMID: 24218603 DOI: 10.1073/pnas.1311371110] [Citation(s) in RCA: 95] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Steroid hormones regulate multiple but distinct aspects of social behaviors. Testosterone (T) has multiple effects on learned courtship song in that it regulates both the motivation to sing in a particular social context as well as the quality of song produced. The neural substrate(s) where T acts to regulate the motivation to sing as opposed to other aspects of song has not been definitively characterized. We show here that T implants in the medial preoptic nucleus (POM) of castrated male canaries (Serinus canaria) increase song rate but do not enhance acoustic features such as song stereotypy compared with birds receiving peripheral T that can act globally throughout the brain. Strikingly, T action in the POM increased song control nuclei volume, consistent with the hypothesis that singing activity induces neuroplasticity in the song control system independent of T acting in these nuclei. When presented with a female canary, POM-T birds copulated at a rate comparable to birds receiving systemic T but produced fewer calls and songs in her presence. Thus, POM is a key site where T acts to activate copulation and increase song rate, an appetitive sexual behavior in songbirds, but T action in other areas of the brain or periphery (e.g., HVC, dopaminergic cell groups, or the syrinx) is required to enhance the quality of song (i.e., stereotypy) as well as regulate context-specific vocalizations. These results have broad implications for research concerning how steroids act at multiple brain loci to regulate distinct sociosexual behaviors and the associated neuroplasticity.
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Charlier TD, Seredynski AL, Niessen NA, Balthazart J. Modulation of testosterone-dependent male sexual behavior and the associated neuroplasticity. Gen Comp Endocrinol 2013; 190:24-33. [PMID: 23523709 PMCID: PMC4761263 DOI: 10.1016/j.ygcen.2013.03.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Revised: 02/26/2013] [Accepted: 03/01/2013] [Indexed: 11/19/2022]
Abstract
Steroids modulate the transcription of a multitude of genes and ultimately influence numerous aspects of reproductive behaviors. Our research investigates how one single steroid, testosterone, is able to trigger this vast number of physiological and behavioral responses. Testosterone potency can be changed locally via aromatization into 17β-estradiol which then activates estrogen receptors of the alpha and beta sub-types. We demonstrated that the independent activation of either receptor activates different aspects of male sexual behavior in Japanese quail. In addition, several studies suggest that the specificity of testosterone action on target genes transcription is related to the recruitment of specific steroid receptor coactivators. We demonstrated that the specific down-regulation of the coactivators SRC-1 or SRC-2 in the medial preoptic nucleus by antisense techniques significantly inhibits steroid-dependent male-typical copulatory behavior and the underlying neuroplasticity. In conclusion, our results demonstrate that the interaction between several steroid metabolizing enzymes, steroid receptors and their coactivators plays a key role in the control of steroid-dependent male sexual behavior and the associated neuroplasticity in quail.
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Affiliation(s)
- Thierry D Charlier
- Research Group in Behavioral Neuroendocrinology, GIGA-Neurosciences, University of Liège, Belgium.
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Monti DM, Raia P, Vroonen J, Maselli V, Van Damme R, Fulgione D. Physiological change in an insular lizard population confirms the reversed island syndrome. Biol J Linn Soc Lond 2012. [DOI: 10.1111/j.1095-8312.2012.02019.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Daria Maria Monti
- Department of Structural and Functional Biology; University of Naples Federico II; 80126; Naples; Italy
| | - Pasquale Raia
- Department of Earth Science; University of Naples Federico II; L.go San Marcellino 10; 80138; Naples; Italy
| | - Jessica Vroonen
- Functional Morphology, Department of Biology; University of Antwerp; Universiteitsplein 1; BE-2610; Wilrijk; Belgium
| | - Valeria Maselli
- Department of Environmental Science; University of Naples 2 SUN; Via Vivaldi; 81100; Caserta; Italy
| | - Raoul Van Damme
- Functional Morphology, Department of Biology; University of Antwerp; Universiteitsplein 1; BE-2610; Wilrijk; Belgium
| | - Domenico Fulgione
- Department of Structural and Functional Biology; University of Naples Federico II; 80126; Naples; Italy
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Dickens MJ, Balthazart J, Cornil CA. Brain aromatase and circulating corticosterone are rapidly regulated by combined acute stress and sexual interaction in a sex-specific manner. J Neuroendocrinol 2012; 24:1322-34. [PMID: 22612582 PMCID: PMC3510384 DOI: 10.1111/j.1365-2826.2012.02340.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Neural production of 17β-oestradiol via aromatisation of testosterone may play a critical role in rapid, nongenomic regulation of physiological and behavioural processes. In brain nuclei implicated in the control of sexual behaviour, sexual or stressfull stimuli induce, respectively, a rapid inhibition or increase in preoptic aromatase activity (AA). In the present study, we tested quail that were either nonstressed or acutely stressed (15 min of restraint) immediately before sexual interaction (5 min) with stressed or nonstressed partners. We measured nuclei-specific AA changes, corresponding behavioural output, fertilisation rates and corticosterone (CORT) concentrations. In males, sexual interaction rapidly reversed stress-induced increases of AA in the medial preoptic nucleus (POM). This time scale (< 5 min) highlights the dynamic potential of the aromatase system to integrate input from stimuli that drive AA in opposing directions. Moreover, acute stress had minimal effects on male behaviour, suggesting that the input from the sexual stimuli on POM AA may actively preserve sexual behaviour despite stress exposure. We also found distinct sex differences in contextual physiological responses: males did not show any effect of partner status, whereas females responded to both their stress exposure and the male partner's stress exposure at the level of circulating CORT and AA. In addition, fertilisation rates and female CORT correlated with the male partner's exhibition of sexually aggressive behaviour, suggesting that female perception of the male can affect their physiology as much as direct stress. Overall, male reproduction appears relatively simple: sexual stimuli, irrespective of stress, drives major neural changes including rapid reversal of stress-induced changes of AA. By contrast, female reproduction appears more nuanced and context specific, with subjects responding physiologically and behaviourally to stress, the male partner's stress exposure, and female-directed male behaviour.
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Affiliation(s)
- M J Dickens
- GIGA Neurosciences, University of Liege, 1 Avenue de l'Hôpital, Liège, Belgium.
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Rosenfeld CS. Effects of Maternal Diet and Exposure to Bisphenol A on Sexually Dimorphic Responses in Conceptuses and Offspring. Reprod Domest Anim 2012; 47 Suppl 4:23-30. [DOI: 10.1111/j.1439-0531.2012.02051.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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O'Connell LA, Hofmann HA. The vertebrate mesolimbic reward system and social behavior network: a comparative synthesis. J Comp Neurol 2012; 519:3599-639. [PMID: 21800319 DOI: 10.1002/cne.22735] [Citation(s) in RCA: 682] [Impact Index Per Article: 56.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
All animals evaluate the salience of external stimuli and integrate them with internal physiological information into adaptive behavior. Natural and sexual selection impinge on these processes, yet our understanding of behavioral decision-making mechanisms and their evolution is still very limited. Insights from mammals indicate that two neural circuits are of crucial importance in this context: the social behavior network and the mesolimbic reward system. Here we review evidence from neurochemical, tract-tracing, developmental, and functional lesion/stimulation studies that delineates homology relationships for most of the nodes of these two circuits across the five major vertebrate lineages: mammals, birds, reptiles, amphibians, and teleost fish. We provide for the first time a comprehensive comparative analysis of the two neural circuits and conclude that they were already present in early vertebrates. We also propose that these circuits form a larger social decision-making (SDM) network that regulates adaptive behavior. Our synthesis thus provides an important foundation for understanding the evolution of the neural mechanisms underlying reward processing and behavioral regulation.
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Affiliation(s)
- Lauren A O'Connell
- Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, Texas 78712, USA
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Balthazart J, Taziaux M, Holloway K, Ball GF, Cornil CA. Behavioral effects of brain-derived estrogens in birds. Ann N Y Acad Sci 2009; 1163:31-48. [PMID: 19456326 DOI: 10.1111/j.1749-6632.2008.03637.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
In birds as in other vertebrates, estrogens produced in the brain by aromatization of testosterone have widespread effects on behavior. Research conducted with male Japanese quail demonstrates that effects of brain estrogens on all aspects of sexual behavior, including appetitive and consummatory components as well as learned aspects, can be divided into two main classes based on their time course. First, estrogens via binding to estrogen receptors regulate the transcription of a variety of genes involved primarily in neurotransmission. These neurochemical effects ultimately result in the activation of male copulatory behavior after a latency of a few days. Correlatively, testosterone and its aromatized metabolites increase the transcription of the aromatase mRNA, resulting in an increased concentration and activity of the enzyme that actually precedes behavioral activation. Second, recent studies with quail demonstrate that brain aromatase activity can also be modulated within minutes by phosphorylation processes regulated by changes in intracellular calcium concentration, such as those associated with glutamatergic neurotransmission. The rapid upregulations or downregulations of brain estrogen concentration (presumably resulting from these changes in aromatase activity) affect, by nongenomic mechanisms with relatively short latencies (frequency increases or decreases respectively within 10-15 min), the expression of male sexual behavior in quail and also in rodents. Brain estrogens thus affect behavior on different time scales by genomic and nongenomic mechanisms similar to those of a hormone or a neurotransmitter.
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Affiliation(s)
- Jacques Balthazart
- Center for Cellular and Molecular Neurobiology, University of Liège, Liège, Belgium.
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Balthazart J, Cornil CA, Charlier TD, Taziaux M, Ball GF. Estradiol, a key endocrine signal in the sexual differentiation and activation of reproductive behavior in quail. ACTA ACUST UNITED AC 2009; 311:323-45. [DOI: 10.1002/jez.464] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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Hosokawa N, Chiba A. Embryonic and posthatching treatments with sex steroids demasculinize the motivational aspects of crowing behavior in male Japanese quail. Horm Behav 2009; 55:139-48. [PMID: 18848946 DOI: 10.1016/j.yhbeh.2008.09.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2008] [Revised: 09/03/2008] [Accepted: 09/12/2008] [Indexed: 11/25/2022]
Abstract
Demasculinizing action of embryonic estrogen on crowing behavior in male Japanese quails was examined. Eggs were treated with either 20 microg of estradiol benzoate (EB) or vehicle on the 10th day of incubation. Chicks hatched from both groups of eggs were injected daily with either testosterone propionate (TP; 10 microg/g b.w.), 5alpha-dihydrotestosterone (DHT, a non-aromatizable androgen; 10 microg/g b.w.), or vehicle from 11 to 50 days after hatching, and during this period their calling behaviors were observed. Irrespective of embryonic treatments, all birds received posthatching treatment with either TP or DHT, but not with vehicle, emitted crows in place of distress calls in a stress (non-sexual) context of being isolated in a recording chamber. The posthatching TP, but not posthatching DHT, induced crowing in a sexual context (crowing in their home-cages) from much earlier age than posthatching vehicle in the birds received control embryonic treatment with vehicle. The same TP treatment, however, completely eliminated the crowing in a sexual context in the birds received EB during their embryonic life. In the birds treated with either posthatching DHT or posthatching vehicle, the crowing in a sexual context was only slightly decreased by embryonic EB treatment. These data suggest that posthatching estrogen, derived from testosterone aromatization, enhances the demasculinizing action of embryonic estrogen, and thus strongly reduces the sexual motivation for crowing behavior. This demasculinizing action, however, would not influence vocal control system which generates acoustic pattern of crowing in the presence of androgens allowing the birds to crow in a non-sexual context.
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Affiliation(s)
- Nami Hosokawa
- Department of Materials and Life Sciences, Sophia University, Tokyo, Japan
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Quinn MJ, Summitt CL, Ottinger MA. Consequences of in ovo exposure to p,p'-DDE on reproductive development and function in Japanese quail. Horm Behav 2008; 53:249-53. [PMID: 18021774 DOI: 10.1016/j.yhbeh.2007.10.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2007] [Revised: 10/02/2007] [Accepted: 10/03/2007] [Indexed: 11/29/2022]
Abstract
This study was conduced to assess the effects of a one time embryonic exposure to p,p'-DDE (dichlorodiphenyldichloroethylene; DDE) on the reproductive development and function in Japanese quail (Coturnix japonica). Embryos were exposed at day one of incubation to either 20 or 40 microg DDE or a sesame oil vehicle control (injection volume=20 microl). Onset of puberty, gonadal histopathology, sperm motility, cloacal gland size, and male copulatory behavior were assessed in adults. DDE accelerated onset of puberty in females and reduced male reproductive behaviors. Gonadal morphology and sperm motility appeared to be unaffected. Results from this study provide evidence that the neuroendocrine system may be more sensitive and less resilient to embryonic exposure to contaminants than traditional measures of reproductive success following contaminant exposure in adults. This study further supports the inclusion of behavioral assessments in toxicity tests.
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Affiliation(s)
- Michael J Quinn
- U.S. Army Center for Health Promotion and Preventive Medicine, Directorate of Toxicology, Health Effects Research Program, Edgewood Area, Bldg. E-2100, Aberdeen Proving Ground, MD 21010, USA.
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Balthazart J, Ball GF. Topography in the preoptic region: differential regulation of appetitive and consummatory male sexual behaviors. Front Neuroendocrinol 2007; 28:161-78. [PMID: 17624413 PMCID: PMC2100381 DOI: 10.1016/j.yfrne.2007.05.003] [Citation(s) in RCA: 167] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2007] [Revised: 05/29/2007] [Accepted: 05/29/2007] [Indexed: 11/29/2022]
Abstract
Several studies have suggested dissociations between neural circuits underlying the expression of appetitive (e.g., courtship behavior) and consummatory components (i.e., copulatory behavior) of vertebrate male sexual behavior. The medial preoptic area (mPOA) clearly controls the expression of male copulation but, according to a number of experiments, is not necessarily implicated in the expression of appetitive sexual behavior. In rats for example, lesions to the mPOA eliminate male-typical copulatory behavior but have more subtle or no obvious effects on measures of sexual motivation. Rats with such lesions still pursue and attempt to mount females. They also acquire and perform learned instrumental responses to gain access to females. However, recent lesions studies and measures of the expression of the immediate early gene c-fos demonstrate that, in quail, sub-regions of the mPOA, in particular of its sexually dimorphic component the medial preoptic nucleus, can be specifically linked with either the expression of appetitive or consummatory sexual behavior. In particular more rostral regions can be linked to appetitive components while more caudal regions are involved in consummatory behavior. This functional sub-region variation is associated with neurochemical and hodological specializations (i.e., differences in chemical phenotype of the cells or in their connectivity), especially those related to the actions of androgens in relation to the activation of male sexual behavior, that are also present in rodents and other species. It could thus reflect general principles about POA organization and function in the vertebrate brain.
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Affiliation(s)
- Jacques Balthazart
- Center for Cellular and Molecular Neurobiology, Research Group in Behavioral Neuroendocrinology, University of Liège, 1 Avenue de 1'Hôpital (Bat. B36), B-4000 Liège 1, Belgium.
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Cornil CA, Ball GF, Balthazart J. Functional significance of the rapid regulation of brain estrogen action: where do the estrogens come from? Brain Res 2006; 1126:2-26. [PMID: 16978590 PMCID: PMC3523229 DOI: 10.1016/j.brainres.2006.07.098] [Citation(s) in RCA: 182] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2006] [Revised: 07/26/2006] [Accepted: 07/27/2006] [Indexed: 12/20/2022]
Abstract
Estrogens exert a wide variety of actions on reproductive and non-reproductive functions. These effects are mediated by slow and long lasting genomic as well as rapid and transient non-genomic mechanisms. Besides the host of studies demonstrating the role of genomic actions at the physiological and behavioral level, mounting evidence highlights the functional significance of non-genomic effects. However, the source of the rapid changes in estrogen availability that are necessary to sustain their fast actions is rarely questioned. For example, the rise of plasma estrogens at pro-estrus that represents one of the fastest documented changes in plasma estrogen concentration appears too slow to explain these actions. Alternatively, estrogen can be synthesized in the brain by the enzyme aromatase providing a source of locally high concentrations of the steroid. Furthermore, recent studies demonstrate that brain aromatase can be rapidly modulated by afferent inputs, including glutamatergic afferents. A role for rapid changes in estrogen production in the central nervous system is supported by experiments showing that acute aromatase inhibition affects nociception as well as male sexual behavior and that preoptic aromatase activity is rapidly (within min) modulated following mating. Such mechanisms thus fulfill the gap existing between the fast actions of estrogen and their mode of production and open new avenues for the understanding of estrogenic effects on the brain.
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Affiliation(s)
- Charlotte A Cornil
- Department of Psychological and Brain Sciences, Johns Hopkins University, 108 Ames Hall, 3400 North Charles Street, Baltimore, MD 21218-2686, USA.
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Ottinger MA, Corbitt C, Hoffman R, Thompson N, Russek-Cohen E, Deviche P. Reproductive aging in Japanese quail, Coturnix japonica is associated with changes in central opioid receptors. Brain Res 2006; 1126:167-75. [PMID: 17045975 DOI: 10.1016/j.brainres.2006.08.110] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2006] [Revised: 08/28/2006] [Accepted: 08/29/2006] [Indexed: 11/28/2022]
Abstract
Quantitative in vitro autoradiography was used to measure specific mu and delta opioid receptor densities in regions of the Japanese quail, Coturnix japonica, brain that regulates reproductive endocrine and behavioral responses to determine the possible involvement of the opioid system in reproductive decline seen during aging. Densities were measured in selected brain regions of young sexually active (YAM), young photoregressed (YPM), old reproductively senescent (OIM) male, young active (YF), and old senescent female (OF) Japanese quail. Medial and lateral septum (SM, SL), medial preoptic area (POM), and n. intercollicularis (ICo) were of particular interest for reproductive responses. Similar to previous observations, mu and delta opioid receptors showed differential distributions in the areas measured. Some age-related changes were observed, with lower SM mu receptor densities in aged males (OIM) than females or young males (YAM). Densities of mu receptors in the POM and in other areas examined did not vary with sex or age. Similarly, OIM males had lower densities of delta receptors in the SM than young males (YAM and YPM); POM delta receptor densities were also low in OIM males compared to the YPM males, and YAM males were intermediate. Interestingly, photoregressed males (YPM) had higher SL delta receptor densities than any other group. Thus there were age-related differences detected in mu receptor densities among groups in the SM of OIM relative to other groups; and the mu and delta receptor densities did not differ in females with brain region. Additionally for delta receptors specifically, YF and OF did not differ from OIM for any brain region and similarly had lower densities of delta receptors compared to YAM males. These data provide support for regional differences in opioid receptor distribution and for age- and sex-related differences in delta opioid receptor densities. The direction of change presents an interesting dichotomy in that, compared to young active males, delta opioid receptor densities increased with loss of reproductive function in the YPM, whereas receptor densities decreased in the OIM. Plasma androgen levels were relatively low in both these groups compared to the young active males. This observation suggests that there is an age-related loss in the ability of this receptor system to respond to circulating and centrally produced steroid hormones in the POM and in some septal regions, compared to young animals that are responding to environmental cues. Furthermore, these data support an active role of the opioid peptide system in the inhibition of the reproductive axis in photoregression.
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Affiliation(s)
- M A Ottinger
- Dept. of Animal and Avian Sciences, University of Maryland, College Park, MD 20742, USA.
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Heimovics SA, Riters LV. Immediate early gene activity in song control nuclei and brain areas regulating motivation relates positively to singing behavior during, but not outside of, a breeding context. ACTA ACUST UNITED AC 2006; 65:207-24. [PMID: 16155901 DOI: 10.1002/neu.20181] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
In some species, such as songbirds, much is known about how the brain regulates vocal learning, production, and perception. What remains a mystery is what regulates the motivation to communicate. European starlings (Sturnus vulgaris) sing throughout most of the year, but the social and environmental factors that motivate singing behavior differ seasonally. Male song is highly sexually motivated during, but not outside of, the breeding season. Brain areas outside the song control system, such as the medial preoptic nucleus (POM) and ventral tegmental area (VTA), have been implicated in regulating sexually motivated behaviors in birds, including song. The present study was designed to explore whether these regions, as well as three song control nuclei [area X, the high vocal center (HVC), and the robust nucleus of the arcopallium (RA)], might be involved differentially in song produced within compared to outside of a breeding context. We recorded the behavioral responses of breeding and nonbreeding condition male starlings to the introduction of a female conspecific. Males did not show context-dependent differences in the overall amount of song sung. However, immunocytochemistry for the protein product of the immediate early gene cFOS revealed a positive linear relationship between the total amount of songs sung and number of cFOS-labeled cells in POM, VTA, HVC, and RA for birds singing during, but not outside of, a breeding context. These results suggest that these regions differentially regulate male song production depending on reproductive context. Overall the data support the hypothesis that the POM and VTA interact with the song control system, specifically HVC and RA, to regulate sexually motivated vocal communication in songbirds.
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Embryonic Effects of Androgen Active Endocrine Disrupting Chemicals on Avian Immune and Reproductive Systems. J Poult Sci 2006. [DOI: 10.2141/jpsa.43.1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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Ottinger MA, Abdelnabi M, Li Q, Chen K, Thompson N, Harada N, Viglietti-Panzica C, Panzica GC. The Japanese quail: a model for studying reproductive aging of hypothalamic systems. Exp Gerontol 2005; 39:1679-93. [PMID: 15582284 DOI: 10.1016/j.exger.2004.06.021] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2004] [Accepted: 06/14/2004] [Indexed: 10/26/2022]
Abstract
During aging, the decline of neuroendocrine, endocrine, and behavioral components of reproduction ultimately leads to reproductive failure. These studies considered both neuroendocrine and behavioral aspects of reproductive aging in Japanese quail, using chronological age and reproductive status to separate animals into experimental groups. In Study I, age-related changes in the gonadotropin releasing hormone (GnRH-I) system were investigated and a sharp decrease was observed in GnRH-I concentration in the median eminence of aging animals of both sexes, whereas preoptic-lateral septal region GnRH-I concentrations declined only in aging males. Immunohistochemistry confirmed these findings since aging females retained, whereas males lost GnRH-I cells. Functional changes were assessed by in vitro incubation of parasaggittal hypothalamic slices collected from young and old inactive males and females. Results showed reduced baseline GnRH-I release and diminished response to norepinephrine (NE). Deteriorating fertility also correlated with decreased male sexual behavior and loss of aromatase immunoreactive (AROM-ir) neurons in the medial, but not lateral preoptic nucleus (POA). Sexual behavior and AROM-ir were restored with exogenous testosterone, which was associated with increased cell size in the medial POA. Comparison of cell size and number of AROM-ir cells showed that aged sexually active males had fewer, larger AROM-ir cells when compared to young males, suggesting neuroplasticity of specific neural systems and a critical role of estradiol in maintaining reproductive function.
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Affiliation(s)
- Mary Ann Ottinger
- Department of Animal and Avian Sciences, University of Maryland, College Park, MD 20742, USA.
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Balthazart J, Baillien M, Cornil CA, Ball GF. Preoptic aromatase modulates male sexual behavior: slow and fast mechanisms of action. Physiol Behav 2005; 83:247-70. [PMID: 15488543 DOI: 10.1016/j.physbeh.2004.08.025] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
In many species, copulatory behavior and appetitive (anticipatory/motivational) aspects of male sexual behavior are activated by the action in the preoptic area of estrogens locally produced by testosterone aromatization. Estrogens bind to intracellular receptors, which then act as transcription factors to activate the behavior. Accordingly, changes in aromatase activity (AA) result from slow steroid-induced modifications of enzyme transcription. More recently, rapid nongenomic effects of estrogens have been described and evidence has accumulated indicating that AA can be modulated by rapid (minutes to hour) nongenomic mechanisms in addition to the slower transcriptional changes. Hypothalamic AA is rapidly down-regulated in conditions that enhance protein phosphorylation, in particular, increases in the intracellular calcium concentration, such as those triggered by neurotransmitter (e.g., glutamate) activity. Fast changes in brain estrogens can thus be caused by aromatase phosphorylation as a result of changes in neurotransmission. In parallel, recent studies demonstrate that the pharmacological blockade of AA by specific inhibitors rapidly (within 15-45 min) down-regulates motivational and consummatory aspects of male sexual behavior in quail while injections of estradiol can rapidly increase the expression of copulatory behavior. These data collectively support an emerging concept in neuroendocrinology, namely that estrogen, locally produced in the brain, regulates male sexual behavior via a combination of genomic and nongenomic mechanisms. Rapid and slower changes of brain AA match well with these two modes of estrogen action and provide temporal variations in the estrogen's bioavailability that can support the entire range of established effects for this steroid.
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Affiliation(s)
- Jacques Balthazart
- Center for Cellular and Molecular Neurobiology, Research Group in Behavioral Neuroendocrinology, University of Liège, 17 place Delcour (Bat. L1), B-4020 Liège, Belgium.
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Abstract
Male sexual behavior in both field and laboratory settings has been studied in birds since the 19th century. Birds are valuable for the investigation of the neuroendocrine mechanisms of sexual behavior, because their behavior can be studied in the context of a large amount of field data, well-defined neural circuits related to reproductive behavior have been described, and the avian neuroendocrine system exhibits many examples of marked plasticity. As is the case in other taxa, male sexual behavior in birds can be usefully divided into an appetitive phase consisting of variable behaviors (typically searching and courtship) that allow an individual to converge on a functional outcome, copulation (consummatory phase). Based primarily on experimental studies in ring doves and Japanese quail, it has been shown that testosterone of gonadal origin plays an important role in the activation of both of these aspects of male sexual behavior. Furthermore, the conversion of androgens, such as testosterone, in the brain to estrogens, such as 17beta-estradiol, is essential for the full expression of male-typical behaviors. The localization of sex steroid receptors and the enzyme aromatase in the brain, along with lesion, hormone implant and immediate early gene expression studies, has identified many neural sites related to the control of male behavior. The preoptic area (POA) is a key site for the integration of sensory inputs and the initiation of motor outputs. Furthermore, prominent connections between the POA and the periaqueductal gray (PAG) form a node that is regulated by steroid hormones, receive sensory inputs and send efferent projections to the brainstem and spinal cord that activate male sexual behaviors. The sensory inputs regulating avian male sexual responses, in contrast to most mammalian species, are primarily visual and auditory, so a future challenge will be to identify how these senses impinge on the POA-PAG circuit. Similarly, most avian species do not have an intromittent organ, so the projections from the POA-PAG to the brainstem and spinal cord that control sexual reflexes will be of particular interest to contrast with the well characterized rodent system. With this knowledge, general principles about the organization of male sexual circuits can be elucidated, and comparative studies relating known species variation in avian male sexual behaviors to variation in neural systems can be pursued.
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Affiliation(s)
- Gregory F Ball
- Department of Psychological and Brain Sciences, Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD 21218, USA.
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Abstract
The song system of zebra finches (Taeniopygia gutatta) is highly sexually dimorphic. Only males sing, and the brain regions and muscles controlling song are much larger in males than in females. Development of the song system is highly sensitive to steroid hormones. However, unlike similar sexually dimorphic systems in other animal models, masculinization of song system structure and function is most likely not induced by testosterone secreted from the testes. Instead, sex-specific development of the neural song system appears to be regulated by factors intrinsic to the brain, probably by the expression of sex chromosome gene(s) that influence the levels of estradiol synthesized in the brain and/or the responses of brain tissue to estradiol. However, the existing data are complex and in some cases contradictory. More work is required to identify the critical genes and their relationships with steroid hormones.
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Affiliation(s)
- Juli Wade
- Department of Psychology, Michigan State University, Neuroscience Program, 108 Giltner Hall, East Lansing, MI 48824-1101, USA.
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Bakker J, Honda S, Harada N, Balthazart J. Sexual partner preference requires a functional aromatase (cyp19) gene in male mice. Horm Behav 2002; 42:158-71. [PMID: 12367569 DOI: 10.1006/hbeh.2002.1805] [Citation(s) in RCA: 113] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Sexual motivation, sexual partner preference, and sexual performance represent three different aspects of sexual behavior that are critical in determining the reproductive success of a species. Although the display of sexual behavior is under strict hormonal control in both sexes, the relative roles of androgen and estrogen receptors in activating the various components of male sexual behavior are still largely unknown. A recently developed mouse model that is deficient in estradiol due to targeted disruption of exons 1 and 2 of the Cyp19 gene (aromatase knockout (ArKO) mice) was used here to analyze the role of estradiol in the control of all three aspects of male sexual behavior. When tested in a Y-maze providing volatile olfactory cues, male ArKO mice did not show a preference for the odors from an estrous female over those from an intact male, whereas wild-type (WT) and heterozygous (HET) males clearly preferred to sniff estrous odors. When provided with visual and olfactory cues, male ArKO mice also failed to show a preference for an estrous female when given a choice between an estrous female and an empty arm. However, sexual partner preferences of male ArKO mice were not sex-reversed: they did not prefer to investigate an intact male over an estrous female or empty arm. Thus, male ArKO mice seemed to have general deficits in discriminating between conspecifics by using olfactory and visual cues. Male coital behavior was also severely impaired in male ArKO mice: they displayed significantly fewer mounts, intromissions, and ejaculations than WT and HET males. Latencies to first mount or intromission were also significantly longer in ArKO males compared to WT and HET males, in addition to them showing less interest in investigating olfactory and visual cues in a Y-maze, suggesting that they were sexually less motivated. However, three out of seven male ArKO mice were capable of siring litters provided they were housed with a female for a prolonged period of time. In conclusion, aromatization of testosterone to estradiol appears to be essential for sexual motivation and sexual partner preference. By contrast, estradiol may play only a limited role in the expression of male coital behaviors.
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Affiliation(s)
- J Bakker
- Center for Cellular and Molecular Neurobiology, Research Group in Behavioral Neuroendocrinology, University of Liège, Liège, B-4020, Belgium
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Ottinger MA, Abdelnabi M, Quinn M, Golden N, Wu J, Thompson N. Reproductive consequences of EDCs in birds: what do laboratory effects mean in field species? Neurotoxicol Teratol 2002; 24:17-28. [PMID: 11836068 DOI: 10.1016/s0892-0362(01)00195-7] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
The varied reproductive strategies of birds present a challenge in developing reliable indices for the assessment of effects of endocrine disrupting chemicals (EDCs). Precocial species, such as quail, appear to be most sensitive to EDC effects during embryonic development. Although the Japanese quail (Coturnix japonica) is a nonnative lab species, its reproductive strategy is similar to that of many free-ranging species. Because a great deal is known about the reproductive biology of this species and Japanese quail have a short generation time, this species is an ideal candidate for testing EDC effects. In this review, we present data collected in a two-generation design with embryonic exposure to estradiol benzoate (EB). This study was conducted to provide fundamental information for establishing reliable reproductive endpoints associated with estrogenic EDC exposure. Data were collected for a variety of endpoints, which were chosen as measures of reproductive capability and success. These reproductive fitness measures included fertility, hatching success, and offspring viability. Endocrine measures consisted of plasma hormone levels and gonad weight/condition. Neuroendocrine systems, such as the monoamine neurotransmitter systems, regulate hypothalamic gonadotropin releasing hormone (GnRH) and reproductive behavior. Therefore, these variables should potentially be very sensitive indicators. Behavioral measures included reproductive behavior. Results showed that embryonic estradiol exposure affected endocrine and behavioral responses in males and impacted productivity in females. Therefore, quails provide an excellent model to determine fundamental actions of EDCs. The laboratory trials then serve as a basis for the extrapolation of findings of controlled laboratory studies to effects that may be observable in free-ranging species.
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Affiliation(s)
- Mary Ann Ottinger
- Department of Animal and Avian Sciences, Room 3113, Animal Sciences Center, University of Maryland, College Park, MD 20742, USA.
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Rosen GJ, Wade J. Androgen metabolism in the brain of the green anole lizard (Anolis carolinensis): effects of sex and season. Gen Comp Endocrinol 2001; 122:40-7. [PMID: 11352552 DOI: 10.1006/gcen.2001.7616] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Courtship behavior in male green anoles is partly mediated by the 5alpha-reductase enzyme, which converts testosterone (T) to 5alpha-dihydrotestosterone. This study aimed to determine whether the activity of 5alpha-reductase is enhanced in breeding males compared to females and nonbreeding males who do not normally display masculine behaviors. In some cases, aromatase, which converts T to 17beta-estradiol, also was assessed to determine whether the pattern of its activity in anoles is similar to that in other vertebrates. 5alpha-Reductase is greatest in the brainstem, so its activity was determined separately in homogenates of whole brain and brainstems. The following comparisons were done in different assays: (1) breeding males with breeding females, (2) nonbreeding males with nonbreeding females, and (3) breeding males with nonbreeding males. Aromatase activity was greater in breeding males (mean +/- SE, 0.61 +/- 0.06 fmol/min/mg protein) than in breeding females (0.41 +/- 0.08 fmol/min/mg protein). It was also greater in breeding males (0.84 +/- 0.16 fmol/min/mg protein) than in nonbreeding males (0.33 +/- 0.07 fmol/min/mg protein). In contrast, sex or seasonal differences did not exist in 5alpha-reductase activity. The results are consistent with those of other vertebrate species in which male-biased sex dimorphisms and seasonal differences occur in aromatase, but not in 5alpha-reductase activity. The greater levels of aromatase activity in breeding male anoles suggest that this enzyme might mediate male-specific functions. The equivalently high levels of 5alpha-reductase activity in both sexes suggests that, in addition to facilitating male courtship behavior, the enzyme has a basic function common to both sexes.
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Affiliation(s)
- G J Rosen
- Department of Psychology, Michigan State University, East Lansing, Michigan 48824, USA
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Iversen P, Melezinek I, Schmidt A. Nonsteroidal antiandrogens: a therapeutic option for patients with advanced prostate cancer who wish to retain sexual interest and function. BJU Int 2001; 87:47-56. [PMID: 11121992 DOI: 10.1046/j.1464-410x.2001.00988.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- P Iversen
- Department of Urology, University of Copenhagen, Rigshospitalet, Copenhagen, Denmark.
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50
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Abstract
Both testosterone (T) and its metabolite, 5alpha-dihydrotestosterone (DHT), can facilitate male sexual behavior in the lizard Anolis carolinensis. The present study addresses the role of DHT synthesis in regulating male sexual behavior by inhibiting 5alpha-reductase, the enzyme that converts T into DHT. In two separate experiments (one replacement and one maintenance paradigm), breeding adult males were castrated and implanted with capsules of T, DHT, or a control capsule (blank, BL). The animals were then injected with the 5alpha-reductase inhibitor, FCE, or with steroid suspending vehicle (SSV) as a control. Both experiments produced similar results. Overall, T was most effective in eliciting courtship and copulatory behaviors above control levels. In both experiments, treatment with FCE attenuated the T-induced effects on courtship behavior, whereas the inhibition of 5alpha-reductase activity resulted in modest and inconsistent effects on the latency to intromission and the proportion of copulating males. DHT treatment did not significantly increase courtship or copulatory behaviors above control levels. These results suggest that (a) 5alpha-reductase activity is necessary but that DHT alone is not sufficient for stimulating courtship in male A. carolinensis; and (b) courtship behavior is more sensitive than copulatory behavior to the activity of the androgen metabolizing enzyme.
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Affiliation(s)
- G J Rosen
- Department of Psychology and Program in Neuroscience, Michigan State University, Psychology Research Building, East Lansing, MI 48824, USA
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