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Ågmo A. Androgen receptors and sociosexual behaviors in mammals: The limits of generalization. Neurosci Biobehav Rev 2024; 157:105530. [PMID: 38176634 DOI: 10.1016/j.neubiorev.2023.105530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Revised: 12/27/2023] [Accepted: 12/29/2023] [Indexed: 01/06/2024]
Abstract
Circulating testosterone is easily aromatized to estradiol and reduced to dihydrotestosterone in target tissues and elsewhere in the body. Thus, the actions of testosterone can be mediated either by the estrogen receptors, the androgen receptor or by simultaneous action at both receptors. To determine the role of androgens acting at the androgen receptor, we need to eliminate actions at the estrogen receptors. Alternatively, actions at the androgen receptor itself can be eliminated. In the present review, I will analyze the specific role of androgen receptors in male and female sexual behavior as well as in aggression. Some comments about androgen receptors and social recognition are also made. It will be shown that there are important differences between species, even between strains within a species, concerning the actions of the androgen receptor on the behaviors mentioned. This fact makes generalizations from one species to another or from one strain to another very risky. The existence of important species differences is often ignored, leading to many misunderstandings and much confusion.
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Affiliation(s)
- Anders Ågmo
- Department of Psychology, University of Tromsø, Norway.
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2
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Hull EM, Dominguez JM. Neuroendocrine Regulation of Male Sexual Behavior. Compr Physiol 2019; 9:1383-1410. [DOI: 10.1002/cphy.c180018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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3
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Onaolapo OJ, Onaolapo AY, Omololu TA, Oludimu AT, Segun-Busari T, Omoleke T. Exogenous Testosterone, Aging, and Changes in Behavioral Response of Gonadally Intact Male Mice. J Exp Neurosci 2016; 10:59-70. [PMID: 27158222 PMCID: PMC4854217 DOI: 10.4137/jen.s39042] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Revised: 03/06/2016] [Accepted: 03/18/2016] [Indexed: 01/23/2023] Open
Abstract
This study tested the hypothesis that aging significantly affects the influence of exogenous testosterone on neurobehavior in gonadally intact male mice. Groups of prepubertal and aged male mice received daily vehicle or testosterone propionate (TP; 2.5 or 5.0 mg/kg intraperitoneal [i.p.]) for 21 days. Behaviors were assessed on days 1 and 21. Weight gain was significant in prepubertal mice. Locomotion and rearing increased in prepubertal mice after first dose and decreased after last dose of TP. Rearing was suppressed in aged mice throughout. Suppression of grooming occurred in both age groups at day 21. Significant increase in working memory in both age groups was seen in the radial-arm maze (at specific doses) and in prepubertal mice in the Y-maze. Elevated plus maze test showed mixed anxiolytic/anxiogenic effects. Aged mice had higher serum testosterone. In conclusion, age is an important determinant for the influence of exogenous testosterone on behavior in gonadally intact male mice.
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Affiliation(s)
- Olakunle J Onaolapo
- Department of Pharmacology, Faculty of Basic Medical Sciences, College of Health Sciences, Ladoke Akintola University of Technology, Oshogbo, Osun State, Nigeria
| | - Adejoke Y Onaolapo
- Department of Human Anatomy, Faculty of Basic Medical Sciences, College of Health Sciences, Ladoke Akintola University of Technology, Ogbomosho, Oyo State, Nigeria
| | - Tope A Omololu
- Department of Human Anatomy, Faculty of Basic Medical Sciences, College of Health Sciences, Ladoke Akintola University of Technology, Ogbomosho, Oyo State, Nigeria
| | - Adedunke T Oludimu
- Department of Human Anatomy, Faculty of Basic Medical Sciences, College of Health Sciences, Ladoke Akintola University of Technology, Ogbomosho, Oyo State, Nigeria
| | - Toluwalase Segun-Busari
- Department of Human Anatomy, Faculty of Basic Medical Sciences, College of Health Sciences, Ladoke Akintola University of Technology, Ogbomosho, Oyo State, Nigeria
| | - Taofeeq Omoleke
- Department of Human Anatomy, Faculty of Basic Medical Sciences, College of Health Sciences, Ladoke Akintola University of Technology, Ogbomosho, Oyo State, Nigeria
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4
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Direct projections from the sacral spinal cord to the medial preoptic area in cat and guinea pig. Neuroscience 2009; 164:1732-43. [DOI: 10.1016/j.neuroscience.2009.08.062] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2009] [Revised: 08/26/2009] [Accepted: 08/27/2009] [Indexed: 01/20/2023]
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Abstract
The hormonal factors and neural circuitry that control copulation are similar across rodent species, although there are differences in specific behavior patterns. Both estradiol (E) and dihydrotestosterone (DHT) contribute to the activation of mating, although E is more important for copulation and DHT for genital reflexes. Hormonal activation of the medial preoptic area (MPOA) is most effective, although implants in the medial amygdala (MeA) can also stimulate mounting in castrates. Chemosensory inputs from the main and accessory olfactory systems are the most important stimuli for mating in rodents, especially in hamsters, although genitosensory input also contributes. Dopamine agonists facilitate sexual behavior, and serotonin (5-HT) is generally inhibitory, though certain 5-HT receptor subtypes facilitate erection or ejaculation. Norepinephrine agonists and opiates have dose-dependent effects, with low doses facilitating and high doses inhibiting behavior.
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Affiliation(s)
- Elaine M Hull
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, FL 32306-1270, USA.
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6
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Moffatt CA. Steroid hormone modulation of olfactory processing in the context of socio-sexual behaviors in rodents and humans. ACTA ACUST UNITED AC 2003; 43:192-206. [PMID: 14572914 DOI: 10.1016/s0165-0173(03)00208-x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Primer pheromones and other chemosensory cues are important factors governing social interactions and reproductive physiology in many species of mammals. Responses to these chemosignals can vary substantially within and between individuals. This variability can stem, at least in part, from the modulating effects steroid and non-steroid hormones exert on olfactory processing. Such modulation frequently augments or facilitates the effects that prevailing social and environmental conditions have on the reproductive axis. The mechanisms underlying the hormonal regulation of responses to chemosensory cues are diverse. They are in part behavioral, achieved through the modulation of chemoinvestigative behaviors, and in part a product of the modulation of the intrinsic responsiveness of the main and accessory olfactory systems to conspecific, as well as other classes, of chemosignals. The behavioral and non-behavioral effects complement one another to ensure that mating and other reproductive processes are confined to reproductively favorable conditions.
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Romeo RD, Richardson HN, Sisk CL. Puberty and the maturation of the male brain and sexual behavior: recasting a behavioral potential. Neurosci Biobehav Rev 2002; 26:381-91. [PMID: 12034137 DOI: 10.1016/s0149-7634(02)00009-x] [Citation(s) in RCA: 114] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The pubertal transition from the juvenile to adult state requires significant changes in behavior to meet the demands for success and survival in adulthood. These behavioral changes during puberty must be mediated by changes in the structure and/or function of the central nervous system. Despite the profound consequences of puberty on an animal's behavioral repertoire, the mechanisms underlying pubertal maturation of the nervous system remain largely unknown. In this review, we provide a synthesis of neural development during puberty as it relates to maturation of male reproductive behavior. We first outline neuroendocrine events associated with puberty and review work from our laboratory that identifies pubertal changes in the neural substrate controlling male reproduction by comparing the neural responses of prepubertal and adult males to steroids and female chemosensory cues. We then raise the question of whether puberty is a sensitive period in which gonadal hormones influence the structural and functional organization of neural circuits underlying male reproductive behavior. The central thesis of this review is that the development of the nervous system during puberty alters the way in which the male responds to social stimuli, involving the restructuring of neural circuits that integrate steroidal and sensory information and ultimately mediate steroid-dependent social behaviors in adulthood.
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Affiliation(s)
- Russell D Romeo
- Department of Psychology and Neuroscience Program, Michigan State University, East Lansing, MI 48824, USA
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8
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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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Pinckard KL, Stellflug J, Resko JA, Roselli CE, Stormshak F. Review: brain aromatization and other factors affecting male reproductive behavior with emphasis on the sexual orientation of rams. Domest Anim Endocrinol 2000; 18:83-96. [PMID: 10701766 DOI: 10.1016/s0739-7240(99)00065-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- K L Pinckard
- Department of Animal Sciences, Oregon State University, Corvallis 97331-6702, USA
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Abstract
Most sexual dimorphisms in reproductive behavior are hormonally organized in the guinea pig. The study sought to determine whether the sexually dimorphic requirement for the aromatization of testosterone in the activation of mounting is organized by testosterone prenatally and whether aromatization of testosterone contributes to the organization of mounting behavior. Pregnant females were treated with testosterone, the aromatase inhibitor ATD, or vehicle from days 28-65 of gestation. The offspring were gonadectomized and tested as adults for lordosis and androgen-activated mounting behavior. Prenatal testosterone treatments altered the hormonal requirements for androgen-activated mounting in females such that they resembled normal males, and did not require aromatization as adults. Prenatal inhibition of aromatase activity decreased mounting activity in females but not in males. This treatment had no influence on lordosis in either sex. The results support the hypothesis that the same hormones that activate mounting behavior in the adult guinea pig are responsible for the organization of mounting behavior.
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Affiliation(s)
- M M Roy
- Neuroscience Training Program, University of Wisconsin-Madison
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Connolly PB, Roselli CE, Resko JA. Androgen-dependent and -independent aromatase activity coexists with androgen receptors in male Guinea-pig brain. J Neuroendocrinol 1991; 3:679-84. [PMID: 19215538 DOI: 10.1111/j.1365-2826.1991.tb00333.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Abstract Using a microdissection technique we localized androgen receptors and aromatase activity (AA) in the brain of male guinea-pigs. In addition, we evaluated the effects of castration and androgen replacement on androgen receptor dynamics and induction of AA. In the castrate animal, cytosolic androgen receptor content was highest in the basal hypothalamus, specifically in the median eminence-arcuate nucleus (> 15 fmol mg protein (1)), while lesser levels were found in the preoptic regions and amygdala. Nuclear receptor content was highest (> 150 fmol mg DNA (-1)) in the median eminence-arcuate nucleus, periventricular region of the preoptic area and cortical amygdala. All regions investigated showed a significant decrease in nuclear receptors following castration and an increase with androgen replacement. However, reciprocal changes in cytosolic androgen receptors were not always evident. Aromatase activity was high in the cortical amygdala, medial amygdala, periventricular region of the preoptic area and bed nucleus of the stria terminalis. Castration and androgen replacement had significant stimulatory effects on AA in the ventral medial hypothalamus, median eminence-arcuate nucleus, cortical amygdala and periventricular regions of the preoptic area and anterior hypothalamus. Thus, androgen receptors and AA are unevenly distributed throughout the subcortical regions of the male guinea-pig brain and respond differently to endocrine stimuli. Our data demonstrate that AA is androgen-dependent in some subcortical regions which contain androgen receptors. Even though nuclear receptors in all brain regions were affected by castration and dihydrotestosterone treatment, the events were not always linked to AA regulation. Due to this difference in regulation, AA may serve divergent functions in guinea-pig brain.
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Affiliation(s)
- P B Connolly
- Department of Physiology, School of Medicine, Oregon Health Sciences University, Portland, Oregon 97201, USA
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Tang YP, Sisk CL. Testosterone in MPOA elicits behavioral but not neuroendocrine responses in ferrets. Brain Res Bull 1991; 26:373-8. [PMID: 2049603 DOI: 10.1016/0361-9230(91)90009-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The amount of time male ferrets were engaged in neck gripping, mounting, and thrusting was quantified in 30-min tests with a receptive female before and after castration. Bilateral cannulae containing a total of approximately 2 mg testosterone propionate (TP) in cocoa butter were then stereotaxically aimed at the medial preoptic area (MPOA). Tests for sexual behavior were conducted on days 3, 7, 14, and 21 postimplantation. Ferrets were histologically categorized as either 1) Miss (implants not in MPOA), 2) Unilateral implant in MPOA, or 3) Bilateral implants in MPOA. The mean amount of time spent neck gripping, mounting, and thrusting increased significantly over castrate levels on postimplantation day 14 in the Bilateral group, but not in the Miss or Unilateral groups. In all groups, mean plasma testosterone concentrations were below or near the lower limit of detectability on the day before TP implantation and on postimplantation test days. In the same plasma samples, luteinizing hormone concentrations were within the normal range of castrated ferrets, and did not significantly decline after TP implantation. These results suggest that the MPOA is a neural site for androgen activation of certain components of reproductive behavior but not for negative feedback on gonadotropin secretion in male ferrets.
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Affiliation(s)
- Y P Tang
- Department of Psychology, Michigan State University, East Lansing 48824
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