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Meng Z, Wang X, Zhang D, Lan Z, Cai X, Bian C, Zhang J. Steroid receptor coactivator-1: The central intermediator linking multiple signals and functions in the brain and spinal cord. Genes Dis 2021; 9:1281-1289. [PMID: 35873031 PMCID: PMC9293692 DOI: 10.1016/j.gendis.2021.06.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 05/31/2021] [Accepted: 06/21/2021] [Indexed: 11/28/2022] Open
Abstract
The effects of steroid hormones are believed to be mediated by their nuclear receptors (NRs). The p160 coactivator family, including steroid receptor coactivator-1 (SRC-1), 2 and 3, has been shown to physically interact with NRs to enhance their transactivational activities. Among which SRC-1 has been predominantly localized in the central nervous system including brain and spinal cord. It is not only localized in neurons but also detectable in neuroglial cells (mainly localized in the nuclei but also detectable in the extra-nuclear components). Although the expression of SRC-1 is regulated by many steroids, it is also regulated by some non-steroidal factors such as injury, sound and light. Functionally, SRC-1 has been implied in normal function such as development and ageing, learning and memory, central regulation on reproductive behaviors, motor and food intake. Pathologically, SRC-1 may play a role in the regulation of neuropsychiatric disorders (including stress, depression, anxiety, and autism spectrum disorder), metabolite homeostasis and obesity as well as tumorigenesis. Under most conditions, the related mechanisms are far from elucidation; although it may regulate spatial memory through Rictor/mTORC2-actin polymerization related synaptic plasticity. Several inhibitors and stimulator of SRC-1 have shown anti-cancer potentials, but whether these small molecules could be used to modulate ageing and central disorder related neuropathology remain unclear. Therefore, to elucidate when and how SRC-1 is turned on and off under different stimuli is very interesting and great challenge for neuroscientists.
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Affiliation(s)
- Zhaoyou Meng
- Department of Neurobiology, Army Medical University, Chongqing 400038, PR China
| | - Xiaoya Wang
- Department of Neurosurgery, Nanchong Central Hospital, the Second Clinical Medical College, North Sichuan Medical College, Nanchong, Sichuan 637000, PR China
| | - Dongmei Zhang
- Department of Dermatology, Southwest Hospital, Army Medical University, Chongqing 400038, PR China
| | - Zhen Lan
- Department of Neurobiology, Army Medical University, Chongqing 400038, PR China
| | - Xiaoxia Cai
- Department of Neurobiology, Army Medical University, Chongqing 400038, PR China
- School of Life Sciences, Southwest University, Chongqing 400715, PR China
| | - Chen Bian
- School of Psychology, Amy Medical University, Chongqing 400038, PR China
- Corresponding author.
| | - Jiqiang Zhang
- Department of Neurobiology, Army Medical University, Chongqing 400038, PR China
- Corresponding author.
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Akinola OB, Gabriel MO. Neuroanatomical and molecular correlates of cognitive and behavioural outcomes in hypogonadal males. Metab Brain Dis 2018; 33:491-505. [PMID: 29230619 DOI: 10.1007/s11011-017-0163-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Accepted: 11/28/2017] [Indexed: 12/18/2022]
Abstract
Robust epidemiological, clinical and laboratory evidence supports emerging roles for the sex steroids in such domains as neurodevelopment, behaviour, learning and cognition. Regions of the mammalian brain that are involved in cognitive development and memory do not only express the classical nuclear androgen receptor, but also the non-genomic membrane receptor, which is a G protein-coupled receptor that mediates some rapid effects of the androgens on neurogenesis and synaptic plasticity. Under physiological conditions, hippocampal neurons do express the enzyme aromatase, and therefore actively aromatize testosterone to oestradiol. Although glial expression of the aromatase enzyme is minimal, increased expression following injury suggests a role for sex steroids in neuroprotection. It is therefore plausible to deduce that low levels of circulating androgens in males would perturb neuronal functions in relation to cognition and memory, as well as neural repair following injury. The present review is an overview of some roles of the sex steroids on cognitive function in males, and the neuroanatomical and molecular underpinnings of some behavioural and cognitive deficits characteristic of such genetic disorders noted for low androgen levels, including Klinefelter syndrome, Bardet-Biedl syndrome, Kallman syndrome and Prader-Willi syndrome. Recent literature in relation to some behavioural and cognitive changes secondary to surgical and pharmacological castration are also appraised.
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Affiliation(s)
- O B Akinola
- Division of Endocrinology, Department of Anatomy, Faculty of Basic Medical Sciences, College of Health Sciences, University of Ilorin, Ilorin, Nigeria.
| | - M O Gabriel
- Division of Endocrinology, Department of Anatomy, Faculty of Basic Medical Sciences, College of Health Sciences, University of Ilorin, Ilorin, Nigeria
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Zhao J, Bian C, Liu M, Zhao Y, Sun T, Xing F, Zhang J. Orchiectomy and letrozole differentially regulate synaptic plasticity and spatial memory in a manner that is mediated by SRC-1 in the hippocampus of male mice. J Steroid Biochem Mol Biol 2018; 178:354-368. [PMID: 29452160 DOI: 10.1016/j.jsbmb.2018.02.007] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Revised: 02/07/2018] [Accepted: 02/12/2018] [Indexed: 11/23/2022]
Abstract
Hippocampal synaptic plasticity is the basis of spatial memory and cognition and is strongly regulated by both testicular androgens (testosterone, T) and hippocampal estrogens (17β-estradiol, E2) converted from T by aromatase, which is inhibited by letrozole (LET), but the contribution of each pathway to spatial memory and the associated mechanisms are unclear. In this study, we first used orchiectomy (ORX) and LET injection to investigate the effects of T and hippocampal E2 on spatial memory and hippocampal synaptic plasticity. Next, we examined the changes in steroid receptors and steroid receptor coactivator-1 (SRC-1) under these treatments. Finally, we constructed an SRC-1 RNA interference lentivirus and an AROM overexpression lentivirus to explore the roles of SRC-1 under T replacement and AROM overexpression. The results revealed spatial memory impairment only after LET. LET induced more actin depolymerization and greater losses of spines, synapses, and postsynaptic proteins compared with ORX. Moreover, although ERα and ERβ were affected by LET and ORX at similar levels, AR, GPR30, and SRC-1 were dramatically decreased by LET compared with ORX. Finally, the T and AROM overexpression-induced changes in synaptic proteins and actin polymerization were blocked by SRC-1 inhibition. These results demonstrate that testicular androgens play a limited role, whereas local E2 is more important for cognition, which may explain why castrated men such as eunuchs usually do not have cognitive disorders. These results also suggest a pivotal role of SRC-1 in the action of steroids; thus, SRC-1 may serve as a novel therapeutic target for cognitive disorders.
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Affiliation(s)
- Jikai Zhao
- Department of Neurobiology, Chongqing Key Laboratory of Neurobiology, Third Military Medical University, Chongqing, 400038, China
| | - Chen Bian
- Department of Military Psychology, College of Psychology, Third Military Medical University, Chongqing, 400038, China
| | - Mengying Liu
- Department of Neurobiology, Chongqing Key Laboratory of Neurobiology, Third Military Medical University, Chongqing, 400038, China
| | - Yangang Zhao
- Department of Neurobiology, Chongqing Key Laboratory of Neurobiology, Third Military Medical University, Chongqing, 400038, China
| | - Tao Sun
- Department of Neurobiology, Chongqing Key Laboratory of Neurobiology, Third Military Medical University, Chongqing, 400038, China
| | - Fangzhou Xing
- Department of Neurobiology, Chongqing Key Laboratory of Neurobiology, Third Military Medical University, Chongqing, 400038, China; School of Life Sciences, Southwest University, Chongqing, 400715, China
| | - Jiqiang Zhang
- Department of Neurobiology, Chongqing Key Laboratory of Neurobiology, Third Military Medical University, Chongqing, 400038, China.
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Bian C, Huang Y, Zhu H, Zhao Y, Zhao J, Zhang J. Steroid Receptor Coactivator-1 Knockdown Decreases Synaptic Plasticity and Impairs Spatial Memory in the Hippocampus of Mice. Neuroscience 2018. [PMID: 29524638 DOI: 10.1016/j.neuroscience.2018.02.034] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Steroids have been demonstrated to play profound roles in the regulation of hippocampal function by acting on their receptors, which need coactivators for their transcriptional activities. Previous studies have shown that steroid receptor coactivator-1 (SRC-1) is the predominant coactivator in the hippocampus, but its exact role and the underlying mechanisms remain unclear. In this study, we constructed SRC-1 RNA interference (RNAi) lentiviruses, injected them into the hippocampus of male mice, and then examined the changes in the expression of selected synaptic proteins, CA1 synapse density, postsynaptic density (PSD) thickness, and in vivo long-term potentiation (LTP). Spatial learning and memory behavior changes were investigated using the Morris water maze. We then transfected the lentiviruses into cultured hippocampal cells and examined the changes in synaptic protein and phospho-cyclic AMP response element-binding protein (pCREB) expression. The in vivo results showed that SRC-1 knockdown significantly decreased the expression of synaptic proteins and CA1 synapse density as well as PSD thickness; SRC-1 knockdown also significantly impaired in vivo LTP and disrupted spatial learning and memory. The in vitro results showed that while the expression of synaptic proteins was significantly decreased by SRC-1 knockdown, pCREB expression was also significantly decreased. The above results suggest a pivotal role of SRC-1 in the regulation of hippocampal synaptic plasticity and spatial learning and memory, strongly indicating SRC-1 may serve as a novel therapeutic target for hippocampus-dependent memory disorders.
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Affiliation(s)
- Chen Bian
- Department of Military Psychology, College of Psychology, Third Military Medical University, Chongqing 400038, China; Department of Neurobiology, Third Military Medical University, Chongqing 400038, China
| | - Yan Huang
- Beijing Institute of Pharmacology and Toxicology, Beijing 100850, China
| | - Haitao Zhu
- Department of Military Psychology, College of Psychology, Third Military Medical University, Chongqing 400038, China; Medical Company, Troops 95848 of People's Liberation Army, Xiaogan, Hubei 432100, China
| | - Yangang Zhao
- Department of Neurobiology, Third Military Medical University, Chongqing 400038, China
| | - Jikai Zhao
- Department of Neurobiology, Third Military Medical University, Chongqing 400038, China
| | - Jiqiang Zhang
- Department of Neurobiology, Third Military Medical University, Chongqing 400038, China.
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5
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Xing FZ, Zhao YG, Zhang YY, He L, Zhao JK, Liu MY, Liu Y, Zhang JQ. Nuclear and membrane estrogen receptor antagonists induce similar mTORC2 activation-reversible changes in synaptic protein expression and actin polymerization in the mouse hippocampus. CNS Neurosci Ther 2018; 24:495-507. [PMID: 29352507 DOI: 10.1111/cns.12806] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Revised: 12/23/2017] [Accepted: 12/24/2017] [Indexed: 11/28/2022] Open
Abstract
AIMS Estrogens play pivotal roles in hippocampal synaptic plasticity through nuclear receptors (nERs; including ERα and ERβ) and the membrane receptor (mER; also called GPR30), but the underlying mechanism and the contributions of nERs and mER remain unclear. Mammalian target of rapamycin complex 2 (mTORC2) is involved in actin cytoskeleton polymerization and long-term memory, but whether mTORC2 is involved in the regulation of hippocampal synaptic plasticity by ERs is unclear. METHODS We treated animals with nER antagonists (MPP/PHTPP) or the mER antagonist (G15) alone or in combination with A-443654, an activator of mTORC2. Then, we examined the changes in hippocampal SRC-1 expression, mTORC2 signaling (rictor and phospho-AKTSer473), actin polymerization (phospho-cofilin and profilin-1), synaptic protein expression (GluR1, PSD95, spinophilin, and synaptophysin), CA1 spine density, and synapse density. RESULTS All of the examined parameters except synaptophysin expression were significantly decreased by MPP/PHTPP and G15 treatment. MPP/PHTPP and G15 induced a similar decrease in most parameters except p-cofilin, GluR1, and spinophilin expression. The ER antagonist-induced decreases in these parameters were significantly reversed by mTORC2 activation, except for the change in SRC-1, rictor, and synaptophysin expression. CONCLUSIONS nERs and mER contribute similarly to the changes in proteins and structures associated with synaptic plasticity, and mTORC2 may be a novel target of hippocampal-dependent dementia such as Alzheimer's disease as proposed by previous studies.
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Affiliation(s)
- Fang-Zhou Xing
- Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), Key Laboratory of Aquatic Science of Chongqing, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, School of Life Sciences, Southwest University, Chongqing, China
| | - Yan-Gang Zhao
- Department of Neurobiology, Third Military Medical University, Chongqing, China
| | - Yuan-Yuan Zhang
- Department of Neurobiology, Third Military Medical University, Chongqing, China
| | - Li He
- School of Nursing, Third Military Medical University, Chongqing, China
| | - Ji-Kai Zhao
- Department of Neurobiology, Third Military Medical University, Chongqing, China
| | - Meng-Ying Liu
- Department of Neurobiology, Third Military Medical University, Chongqing, China
| | - Yan Liu
- Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), Key Laboratory of Aquatic Science of Chongqing, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, School of Life Sciences, Southwest University, Chongqing, China
| | - Ji-Qiang Zhang
- Department of Neurobiology, Third Military Medical University, Chongqing, China
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Gray JD, Kogan JF, Marrocco J, McEwen BS. Genomic and epigenomic mechanisms of glucocorticoids in the brain. Nat Rev Endocrinol 2017; 13:661-673. [PMID: 28862266 DOI: 10.1038/nrendo.2017.97] [Citation(s) in RCA: 137] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Following the discovery of glucocorticoid receptors in the hippocampus and other brain regions, research has focused on understanding the effects of glucocorticoids in the brain and their role in regulating emotion and cognition. Glucocorticoids are essential for adaptation to stressors (allostasis) and in maladaptation resulting from allostatic load and overload. Allostatic overload, which can occur during chronic stress, can reshape the hypothalamic-pituitary-adrenal axis through epigenetic modification of genes in the hippocampus, hypothalamus and other stress-responsive brain regions. Glucocorticoids exert their effects on the brain through genomic mechanisms that involve both glucocorticoid receptors and mineralocorticoid receptors directly binding to DNA, as well as by non-genomic mechanisms. Furthermore, glucocorticoids synergize both genomically and non-genomically with neurotransmitters, neurotrophic factors, sex hormones and other stress mediators to shape an organism's present and future responses to a stressful environment. Here, we discuss the mechanisms of glucocorticoid action in the brain and review how glucocorticoids interact with stress mediators in the context of allostasis, allostatic load and stress-induced neuroplasticity.
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Affiliation(s)
- Jason D Gray
- Harold and Margaret Milliken Hatch Laboratory of Neuroendocrinology, The Rockefeller University, 1230 York Avenue, New York, NY 10065. USA
| | - Joshua F Kogan
- Harold and Margaret Milliken Hatch Laboratory of Neuroendocrinology, The Rockefeller University, 1230 York Avenue, New York, NY 10065. USA
| | - Jordan Marrocco
- Harold and Margaret Milliken Hatch Laboratory of Neuroendocrinology, The Rockefeller University, 1230 York Avenue, New York, NY 10065. USA
| | - Bruce S McEwen
- Harold and Margaret Milliken Hatch Laboratory of Neuroendocrinology, The Rockefeller University, 1230 York Avenue, New York, NY 10065. USA
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7
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Qiu L, Zhao Y, Guo Q, Zhang Y, He L, Li W, Zhang J. Dose-dependent regulation of steroid receptor coactivator-1 and steroid receptors by testosterone propionate in the hippocampus of adult male mice. J Steroid Biochem Mol Biol 2016; 156:23-31. [PMID: 26607693 DOI: 10.1016/j.jsbmb.2015.11.012] [Citation(s) in RCA: 16] [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: 08/18/2015] [Revised: 11/13/2015] [Accepted: 11/16/2015] [Indexed: 01/08/2023]
Abstract
Androgens have been proposed to play important roles in the regulation of hippocampus function either directly, through the androgen receptor (AR), or indirectly, through estrogen receptors (ERs), after aromatization into estradiol. Steroid receptor coactivator-1 (SRC-1) is present in the hippocampus of several species, and its expression is regulated by development and aging, as well as by orchidectomy and aromatase inhibitor letrozole administration, while ovariectomy only transiently downregulated hippocampal SRC-1. However, whether the expression of hippocampal SRC-1 can be directly regulated by testosterone, the principal male sex hormone, remains unclear. In the present study, we investigated the expression of hippocampal SRC-1 after orchidectomy and testosterone treatment using immunohistochemistry and Western blot analysis. We found that while hippocampal SRC-1 was significantly downregulated by orchidectomy (ORX), its expression was rescued by treatment with testosterone in a dose-dependent manner. Furthermore, we noticed that the decreased expression of hippocampal AR, ERs and the synaptic proteins GluR-1 and PSD-95 induced by ORX was also rescued by testosterone treatment in a dose-dependent manner. However, we found that hippocampal membrane estrogen receptor GPR30 and dendritic spine marker spinophilin were not altered by ORX or testosterone treatment. Together, the above results provided the first direct evidence for the androgenic regulation on hippocampal SRC-1, indicating that SRC-1 may be a direct target of androgenic regulation on the hippocampus. Furthermore, because AR and ERs can be differentially regulated by testosterone, and the transcriptional activity requires the involvement of local SRC-1, and considering the complicated regulatory pathway of each individual receptor, the converged hub regulator SRC-1 of these nuclear receptor networks is worthy of further investigation.
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Affiliation(s)
- Linli Qiu
- Department of Neurobiology, Chongqing Key Laboratory of Neurobiology, Third Military Medical University, Chongqing 400038, China; Department of Filed Nursing, School of Nursing, Third Military Medical University, Chongqing 400038, China
| | - Yangang Zhao
- Department of Neurobiology, Chongqing Key Laboratory of Neurobiology, Third Military Medical University, Chongqing 400038, China
| | - Qiang Guo
- Department of Neurobiology, Chongqing Key Laboratory of Neurobiology, Third Military Medical University, Chongqing 400038, China
| | - Yuanyuan Zhang
- Department of Neurobiology, Chongqing Key Laboratory of Neurobiology, Third Military Medical University, Chongqing 400038, China
| | - Li He
- Department of Neurobiology, Chongqing Key Laboratory of Neurobiology, Third Military Medical University, Chongqing 400038, China; Department of Filed Nursing, School of Nursing, Third Military Medical University, Chongqing 400038, China
| | - Wei Li
- Department of Filed Nursing, School of Nursing, Third Military Medical University, Chongqing 400038, China.
| | - Jiqiang Zhang
- Department of Neurobiology, Chongqing Key Laboratory of Neurobiology, Third Military Medical University, Chongqing 400038, China.
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Liu M, Huangfu X, Zhao Y, Zhang D, Zhang J. Steroid receptor coactivator-1 mediates letrozole induced downregulation of postsynaptic protein PSD-95 in the hippocampus of adult female rats. J Steroid Biochem Mol Biol 2015. [PMID: 26223010 DOI: 10.1016/j.jsbmb.2015.07.011] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Hippocampus local estrogen which is converted from androgen that catalyzed by aromatase has been shown to play important roles in the regulation of learning and memory as well as cognition through action on synaptic plasticity, but the underlying mechanisms are poorly understood. Steroid receptor coactivator-1 (SRC-1) is one of the coactivators of steroid nuclear receptors; it is widely distributed in brain areas that related to learning and memory, reproductive regulation, sensory and motor information integration. Previous studies have revealed high levels of SRC-1 immunoreactivities in the hippocampus; it is closely related to the levels of synaptic proteins such as PSD-95 under normal development or gonadectomy, but its exact roles in the regulation of these proteins remains unclear. In this study, we used aromatase inhibitor letrozole in vivo and SRC-1 RNA interference in vitro to investigate whether SRC-1 mediated endogenous estrogen regulation of hippocampal PSD-95. The results revealed that letrozole injection synchronously decreased hippocampal SRC-1 and PSD-95 in a dose-dependant manner. Furthermore, when SRC-1 specific shRNA pool was applied to block the expression of SRC-1 in the primary hippocampal neuron culture, both immunocytochemistry and Western blot revealed that levels of PSD-95 were also decreased significantly. Taking together, these results provided the first evidence that SRC-1 mediated endogenous estrogen regulation of hippocampal synaptic plasticity by targeting the expression of synaptic protein PSD-95. Additionally, since letrozole is frequently used to treat estrogen-sensitive breast cancer, the above results also indicate its potential side effects in clinical administration.
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Affiliation(s)
- Mengying Liu
- Department of Neurobiology, Chongqing Key Laboratory of Neurobiology, Third Military Medical University, Chongqing 400038, China; Cadet Brigade, Third Military Medical University, Chongqing 400038, China
| | - Xuhong Huangfu
- Department of Neurobiology, Chongqing Key Laboratory of Neurobiology, Third Military Medical University, Chongqing 400038, China; Cadet Brigade, Third Military Medical University, Chongqing 400038, China
| | - Yangang Zhao
- Department of Neurobiology, Chongqing Key Laboratory of Neurobiology, Third Military Medical University, Chongqing 400038, China
| | - Dongmei Zhang
- Department of Neurobiology, Chongqing Key Laboratory of Neurobiology, Third Military Medical University, Chongqing 400038, China; Department of Dermatology, Southwest Hospital, Third Military Medical University, Chongqing 400038, China.
| | - Jiqiang Zhang
- Department of Neurobiology, Chongqing Key Laboratory of Neurobiology, Third Military Medical University, Chongqing 400038, China.
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Kerver HN, Wade J. Hormonal regulation of steroid receptor coactivator-1 mRNA in the male and female green anole brain. J Neuroendocrinol 2015; 27:223-33. [PMID: 25557947 DOI: 10.1111/jne.12249] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Revised: 12/10/2014] [Accepted: 12/12/2014] [Indexed: 01/02/2023]
Abstract
Green anole lizards are seasonal breeders, with male sexual behaviour primarily regulated by an annual increase in testosterone. Morphological, biochemical and behavioural changes associated with reproduction are activated by testosterone, generally with a greater effect in the breeding season (BS) than in the nonbreeding season (NBS). The present study investigates the possibility that differences in a steroid receptor coactivator may regulate this seasonal difference in responsiveness to testosterone. In situ hybridisation was used to examine the expression of steroid receptor coactivator-1 (SRC-1) in the brains of gonadally intact male and female green anoles across breeding states. A second experiment examined gonadectomised animals with and without testosterone treatment. Gonadally intact males had more SRC-1 expressing cells in the preoptic area and larger volumes of this region as defined by these cells than females. Main effects of both sex and season (males > females and BS > NBS) were present in cell number and volume of the ventromedial hypothalamus. An interaction between sex and season suggested that high expression in BS males was driving these effects. In hormone-manipulated animals, testosterone treatment increased both the number of SRC-1 expressing cells in and volumes of the preoptic area and amygdala. These results suggest that testosterone selectively regulates SRC-1, and that this coactivator may play a role in facilitating reproductive behaviours across both sexes. However, changes in SRC-1 expression are not likely responsible for the seasonal change in responsiveness to testosterone.
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Affiliation(s)
- H N Kerver
- Neuroscience Program, Michigan State University, East Lansing, MI, USA
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