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Mendell AL, Atwi S, Bailey CDC, McCloskey D, Scharfman HE, MacLusky NJ. Expansion of mossy fibers and CA3 apical dendritic length accompanies the fall in dendritic spine density after gonadectomy in male, but not female, rats. Brain Struct Funct 2017; 222:587-601. [PMID: 27283589 PMCID: PMC5337402 DOI: 10.1007/s00429-016-1237-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2015] [Accepted: 05/19/2016] [Indexed: 11/25/2022]
Abstract
Androgen loss is an important clinical concern because of its cognitive and behavioral effects. Changes in androgen levels are also suspected to contribute to neurological disease. However, the available data on the effects of androgen deprivation in areas of the brain that are central to cognition, like the hippocampus, are mixed. In this study, morphological analysis of pyramidal cells was used to investigate if structural changes could potentially contribute to the mixed cognitive effects that have been observed after androgen loss in males. Male Sprague-Dawley rats were orchidectomized or sham-operated. Two months later, their brains were Golgi-impregnated for morphological analysis. Morphological endpoints were studied in areas CA3 and CA1, with comparisons to females either intact or 2 months after ovariectomy. CA3 pyramidal neurons of orchidectomized rats exhibited marked increases in apical dendritic arborization. There were increases in mossy fiber afferent density in area CA3, as well as robust enhancements to dendritic structure in area CA3 of orchidectomized males, but not in CA1. Remarkably, apical dendritic length of CA3 pyramidal cells increased, while spine density declined. By contrast, in females overall dendritic structure was minimally affected by ovariectomy, while dendritic spine density was greatly reduced. Sex differences and subfield-specific effects of gonadal hormone deprivation on the hippocampal circuitry may help explain the different behavioral effects reported in males and females after gonadectomy, or other conditions associated with declining gonadal hormone secretion.
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Affiliation(s)
- Ari L Mendell
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, ON, N1G 2W1, Canada
| | - Sarah Atwi
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, ON, N1G 2W1, Canada
| | - Craig D C Bailey
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, ON, N1G 2W1, Canada
| | - Dan McCloskey
- Nathan Kline Institute for Psychiatric Research, Center of Dementia Research, Orangeburg, NY, 10962, USA
- Department of Child and Adolescent Psychiatry, New York University Langone Medical Center, New York, NY, 10016, USA
- Department of Physiology and Neuroscience, New York University Langone Medical Center, New York, NY, 10016, USA
- Department of Psychiatry, New York University Langone Medical Center, New York, NY, 10016, USA
- Department of Psychology, College of Staten Island, City University of New York, New York, 10314, USA
| | - Helen E Scharfman
- Nathan Kline Institute for Psychiatric Research, Center of Dementia Research, Orangeburg, NY, 10962, USA
- Department of Child and Adolescent Psychiatry, New York University Langone Medical Center, New York, NY, 10016, USA
- Department of Physiology and Neuroscience, New York University Langone Medical Center, New York, NY, 10016, USA
- Department of Psychiatry, New York University Langone Medical Center, New York, NY, 10016, USA
| | - Neil J MacLusky
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, ON, N1G 2W1, Canada.
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Zancan M, Dall'Oglio A, Quagliotto E, Rasia‐Filho AA. Castration alters the number and structure of dendritic spines in the male posterodorsal medial amygdala. Eur J Neurosci 2016; 45:572-580. [DOI: 10.1111/ejn.13460] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Revised: 10/22/2016] [Accepted: 10/31/2016] [Indexed: 01/21/2023]
Affiliation(s)
- Mariana Zancan
- Department of Basic Sciences/Physiology Federal University of Health Sciences Sarmento Leite 245 Porto Alegre RS 90050‐170 Brazil
- Graduation Program in Neuroscience Federal University of Rio Grande do Sul Porto Alegre Brazil
| | - Aline Dall'Oglio
- Department of Basic Sciences/Physiology Federal University of Health Sciences Sarmento Leite 245 Porto Alegre RS 90050‐170 Brazil
| | - Edson Quagliotto
- Department of Basic Sciences/Physiology Federal University of Health Sciences Sarmento Leite 245 Porto Alegre RS 90050‐170 Brazil
| | - Alberto A. Rasia‐Filho
- Department of Basic Sciences/Physiology Federal University of Health Sciences Sarmento Leite 245 Porto Alegre RS 90050‐170 Brazil
- Graduation Program in Neuroscience Federal University of Rio Grande do Sul Porto Alegre Brazil
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Development-dependent behavioral change toward pups and synaptic transmission in the rhomboid nucleus of the bed nucleus of the stria terminalis. Behav Brain Res 2016; 325:131-137. [PMID: 27793732 DOI: 10.1016/j.bbr.2016.10.029] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Revised: 10/03/2016] [Accepted: 10/19/2016] [Indexed: 11/22/2022]
Abstract
Sexually naïve male C57BL/6 mice aggressively bite unfamiliar pups. This behavior, called infanticide, is considered an adaptive reproductive strategy of males of polygamous species. We recently found that the rhomboid nucleus of the bed nucleus of the stria terminalis (BSTrh) is activated during infanticide and that the bilateral excitotoxic lesions of BSTrh suppress infanticidal behavior. Here we show that 3-week-old male C57BL/6 mice rarely engaged in infanticide and instead, provided parental care toward unfamiliar pups, consistent with observations in rats and other rodent species. This inhibition of infanticide at the periweaning period is functional because the next litter will be born at approximately the time of weaning of the previous litter through maternal postpartum ovulation. However, the mechanism of this age-dependent behavioral change is unknown. Therefore, we performed whole-cell patch clamp recordings of BSTrh and compared evoked neurotransmission in response to the stimulation of the stria terminalis of adult and 3-week-old male mice. Although we were unable to detect a significant difference in the amplitudes of inhibitory neurotransmission, the amplitudes and the paired-pulse ratio of evoked excitatory postsynaptic currents differed between adult and 3-week-old mice. These data suggest that maturation of the synaptic terminal in BSTrh that occurred later than 3 weeks after birth may mediate by the adaptive change from parental to infanticidal behavior in male mice.
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54
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Competition, testosterone, and adult neurobehavioral plasticity. PROGRESS IN BRAIN RESEARCH 2016; 229:213-238. [PMID: 27926439 DOI: 10.1016/bs.pbr.2016.05.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Motivation in performance is often measured via competitions. Winning a competition has been found to increase the motivation to perform in subsequent competitions. One potential neurobiological mechanism that regulates the motivation to compete involves sex hormones, such as the steroids testosterone and estradiol. A wealth of studies in both nonhuman animals and humans have shown that a rise in testosterone levels before and after winning a competition enhances the motivation to compete. There is strong evidence for acute behavioral effects in response to steroid hormones. Intriguingly, a substantial testosterone surge following a win also appears to improve an individual's performance in later contests resulting in a higher probability of winning again. These effects may occur via androgen and estrogen pathways modulating dopaminergic regions, thereby behavior on longer timescales. Hormones thus not only regulate and control social behavior but are also key to adult neurobehavioral plasticity. Here, we present literature showing hormone-driven behavioral effects that persist for extended periods of time beyond acute effects of the hormone, highlighting a fundamental role of sex steroid hormones in adult neuroplasticity. We provide an overview of the relationship between testosterone, motivation measured from objective effort, and their influence in enhancing subsequent effort in competitions. Implications for an important role of testosterone in enabling neuroplasticity to improve performance will be discussed.
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Jacome LF, Barateli K, Buitrago D, Lema F, Frankfurt M, Luine VN. Gonadal Hormones Rapidly Enhance Spatial Memory and Increase Hippocampal Spine Density in Male Rats. Endocrinology 2016; 157:1357-62. [PMID: 26844375 PMCID: PMC4816741 DOI: 10.1210/en.2015-1959] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
17β-estradiol (E2) rapidly, within minutes, activates behaviors and cognition by binding to membrane estrogen receptors, activating cell signaling cascades and increasing dendritic spines. In female rodents, E2 enhances spatial memory within 2-4 hours, and spine density is increased in the CA1 area of the hippocampus within 30-60 minutes. Although chronic gonadal hormone treatments in male rats alter cognition and spines/spine synapses and acute hormone effects occur in hippocampal slices, effects of acute, in vivo hormone administration in males are unknown. Therefore, we assessed rapid effects of E2 (20 μg/kg) and testosterone (T) (750 μg/kg) on spatial memory using the object placement task and on hippocampal spine density using Golgi impregnation. Orchidectomized rats received hormones immediately after the training trial and were tested for retention 2 hours later. Vehicle-injected orchidectomized males spent equal time exploring objects in the old and new locations, but E2- or T-treated subjects spent more time exploring objects at the new location, suggesting enhanced memory. Both hormones also increased spine density in CA1, but not the dentate gyrus, by 20%-40% at 30 minutes and 2 hours after injections. This report is the first, to our knowledge, to show E2 and T enhancements of memory and spine density within such a short time frame in male rats.
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Affiliation(s)
- Luis F Jacome
- Department of Psychology (L.F.J., K.B., D.B., F.L., V.N.L.), Hunter College of City University of New York, New York, New York 10021; and Department of Science Education (M.F.), Hofstra North Shore Long Island Jewish School of Medicine, Hempstead, New York 11549
| | - Ketti Barateli
- Department of Psychology (L.F.J., K.B., D.B., F.L., V.N.L.), Hunter College of City University of New York, New York, New York 10021; and Department of Science Education (M.F.), Hofstra North Shore Long Island Jewish School of Medicine, Hempstead, New York 11549
| | - Dina Buitrago
- Department of Psychology (L.F.J., K.B., D.B., F.L., V.N.L.), Hunter College of City University of New York, New York, New York 10021; and Department of Science Education (M.F.), Hofstra North Shore Long Island Jewish School of Medicine, Hempstead, New York 11549
| | - Franklin Lema
- Department of Psychology (L.F.J., K.B., D.B., F.L., V.N.L.), Hunter College of City University of New York, New York, New York 10021; and Department of Science Education (M.F.), Hofstra North Shore Long Island Jewish School of Medicine, Hempstead, New York 11549
| | - Maya Frankfurt
- Department of Psychology (L.F.J., K.B., D.B., F.L., V.N.L.), Hunter College of City University of New York, New York, New York 10021; and Department of Science Education (M.F.), Hofstra North Shore Long Island Jewish School of Medicine, Hempstead, New York 11549
| | - Victoria N Luine
- Department of Psychology (L.F.J., K.B., D.B., F.L., V.N.L.), Hunter College of City University of New York, New York, New York 10021; and Department of Science Education (M.F.), Hofstra North Shore Long Island Jewish School of Medicine, Hempstead, New York 11549
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56
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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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57
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Pintana H, Pratchayasakul W, Sa-nguanmoo P, Pongkan W, Tawinvisan R, Chattipakorn N, Chattipakorn SC. Testosterone deprivation has neither additive nor synergistic effects with obesity on the cognitive impairment in orchiectomized and/or obese male rats. Metabolism 2016; 65:54-67. [PMID: 26773929 DOI: 10.1016/j.metabol.2015.10.015] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 10/02/2015] [Accepted: 10/05/2015] [Indexed: 12/20/2022]
Abstract
OBJECTIVE Previous studies demonstrated a correlation between cognitive decline and either testosterone deprivation or obesity. However, the effect of obesity combined with testosterone deprivation on cognitive function has not been investigated. This study investigated the effects of obesity on brain insulin sensitivity, brain mitochondrial function, hippocampal synaptic plasticity and cognitive function in testosterone-deprived male rats. MATERIALS/METHODS Male Wistar rats were divided into sham-operated (control) and bilateral orchiectomized (ORX) groups. Rats in each group were further divided into two subgroups to receive either a normal diet (ND) or a high fat diet (HFD) for 4, 8 or 12weeks. Blood samples were collected to determine metabolic parameters. Cognitive function was tested using the Morris Water Maze Test. At the end of the study, brains were removed to investigate brain insulin sensitivity, brain mitochondrial function and hippocampal synaptic plasticity. RESULTS Both control-obese and ORX-obese rats developed peripheral insulin resistance at week eight, and brain insulin resistance as well as brain mitochondrial dysfunction at week 12. However, the ORX-obese rats developed cognitive impairment and decreased hippocampal synaptic plasticity beginning at week eight, whereas the control-obese rats developed these impairments later at week 12. Although both peripheral and brain insulin resistance were not observed in both the control-lean and ORX-lean rats, impaired cognition and decreased hippocampal synaptic plasticity were found in the ORX-lean rats beginning at week eight. CONCLUSION These findings suggest that testosterone deprivation has neither additive nor synergistic effects over obesity in the development of cognitive dysfunction in orchiectomized-obese male rats.
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Affiliation(s)
- Hiranya Pintana
- Neurophysiology Unit, Cardiac Electrophysiology Research and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand; Department of Physiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Wasana Pratchayasakul
- Neurophysiology Unit, Cardiac Electrophysiology Research and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand; Department of Physiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Piangkwan Sa-nguanmoo
- Neurophysiology Unit, Cardiac Electrophysiology Research and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand; Department of Physiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Wanpitak Pongkan
- Neurophysiology Unit, Cardiac Electrophysiology Research and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand; Department of Physiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Rungroj Tawinvisan
- Neurophysiology Unit, Cardiac Electrophysiology Research and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand; Department of Physiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Nipon Chattipakorn
- Neurophysiology Unit, Cardiac Electrophysiology Research and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand; Department of Physiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Siriporn C Chattipakorn
- Neurophysiology Unit, Cardiac Electrophysiology Research and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand; Department of Oral Biology and Diagnostic Sciences, Faculty of Dentistry, Chiang Mai University, Chiang Mai, Thailand.
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58
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Auer MK, Hellweg R, Briken P, Stalla GK, T'Sjoen G, Fuss J. Serum brain-derived neurotrophic factor (BDNF) is not regulated by testosterone in transmen. Biol Sex Differ 2016; 7:1. [PMID: 26753091 PMCID: PMC4705590 DOI: 10.1186/s13293-015-0055-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 12/28/2015] [Indexed: 11/10/2022] Open
Abstract
Brain morphology significantly differs between the sexes. It has been shown before that some of these differences are attributable to the sex-specific hormonal milieu. Brain-derived neurotrophic factor (BDNF) is involved in myriads of neuroplastic processes and shows a sexual dimorphism. Transsexual persons may serve as a model to study sex steroid-mediated effects on brain plasticity. We have recently demonstrated that serum levels of BDNF are reduced in transwomen following 12 months of cross-sex hormone treatment. We now wanted to look at the effects of testosterone treatment on BDNF in transmen. In contrast to our initial hypothesis, BDNF levels did not significantly change, despite dramatic changes in the sex-hormonal milieu. Our data indicate that testosterone does not seem to play a major role in the regulation of BDNF in females.
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Affiliation(s)
- Matthias K Auer
- Endocrinology, Diabetology and Internal Medicine, Max Planck Institute of Psychiatry, Kraepelinstr. 2-10, 80804 Munich, Germany
| | - Rainer Hellweg
- Department of Psychiatry, University of Medicine of Berlin, Campus Charité Mitte, Bonhoefferweg 3, 10117 Berlin, Germany
| | - Peer Briken
- Institute for Sex Research and Forensic Psychiatry, Center for Psychosocial Medicine, University Medical Center Hamburg-Eppendorf, Martininstr. 52, 20246 Hamburg, Germany
| | - Günter K Stalla
- Endocrinology, Diabetology and Internal Medicine, Max Planck Institute of Psychiatry, Kraepelinstr. 2-10, 80804 Munich, Germany
| | - Guy T'Sjoen
- Department of Endocrinology, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium
| | - Johannes Fuss
- Institute for Sex Research and Forensic Psychiatry, Center for Psychosocial Medicine, University Medical Center Hamburg-Eppendorf, Martininstr. 52, 20246 Hamburg, Germany
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59
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Wang SY, Freeman MR, Sathish V, Thompson MA, Pabelick CM, Prakash YS. Sex Steroids Influence Brain-Derived Neurotropic Factor Secretion From Human Airway Smooth Muscle Cells. J Cell Physiol 2015; 231:1586-92. [PMID: 26566264 DOI: 10.1002/jcp.25254] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Accepted: 11/11/2015] [Indexed: 12/15/2022]
Abstract
Brain derived neurotropic factor (BDNF) is emerging as an important player in airway inflammation, remodeling, and hyperreactivity. Separately, there is increasing evidence that sex hormones contribute to pathophysiology in the lung. BDNF and sex steroid signaling are thought to be intricately linked in the brain. There is currently little information on BDNF and sex steroid interactions in the airway but is relevant to understanding growth factor signaling in the context of asthma in men versus women. In this study, we assessed the effect of sex steroids on BDNF expression and secretion in human airway smooth muscle (ASM). Human ASM was treated with estrogen (E2 ) or testosterone (T, 10 nM each) and intracellular BDNF and secreted BDNF measured. E2 and T significantly reduced secretion of BDNF; effects prevented by estrogen and androgen receptor inhibitor, ICI 182,780 (1 μM), and flutamide (10 μM), respectively. Interestingly, no significant changes were observed in intracellular BDNF mRNA or protein expression. High affinity BDNF receptor, TrkB, was not altered by E2 or T. E2 (but not T) significantly increased intracellular cyclic AMP levels. Notably, Epac1 and Epac2 expression were significantly reduced by E2 and T. Furthermore, SNARE complex protein SNAP25 was decreased. Overall, these novel data suggest that physiologically relevant concentrations of E2 or T inhibit BDNF secretion in human ASM, suggesting a potential interaction of sex steroids with BDNF in the airway that is different from brain. The relevance of sex steroid-BDNF interactions may lie in their overall contribution to airway diseases such as asthma.
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Affiliation(s)
- Sheng-Yu Wang
- Department of Respiratory Medicine, First Affiliated Hospital of Xi'an Medical University, Xi'an, Shaanxi, PR China.,Department of Anesthesiology, Mayo Clinic, Rochester, Minnesota
| | | | - Venkatachalem Sathish
- Department of Anesthesiology, Mayo Clinic, Rochester, Minnesota.,Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota
| | | | - Christina M Pabelick
- Department of Anesthesiology, Mayo Clinic, Rochester, Minnesota.,Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota
| | - Y S Prakash
- Department of Anesthesiology, Mayo Clinic, Rochester, Minnesota.,Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota
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Pintana H, Chattipakorn N, Chattipakorn S. Testosterone deficiency, insulin-resistant obesity and cognitive function. Metab Brain Dis 2015; 30:853-76. [PMID: 25703239 DOI: 10.1007/s11011-015-9655-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Accepted: 02/03/2015] [Indexed: 12/29/2022]
Abstract
Testosterone is an androgenic steroid hormone, which plays an important role in the regulation of male reproduction and behaviors, as well as in the maintenance of insulin sensitivity. Several studies showed that testosterone exerted beneficial effects in brain function, including preventing neuronal cell death, balancing brain oxidative stress and antioxidant activity, improving synaptic plasticity and involving cognitive formation. Although previous studies showed that testosterone deficiency is positively correlated with cognitive impairment and insulin-resistant obesity, several studies demonstrated contradictory findings. Thus, this review comprehensively summarizes the current evidence from in vitro, in vivo and clinical studies of the relationship between testosterone deficiency and insulin-resistant obesity as well as the correlation between either insulin-resistant obesity or testosterone deficiency and cognitive impairment. Controversial reports and the mechanistic insights regarding the roles of testosterone in insulin-resistant obesity and cognitive function are also presented and discussed.
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Affiliation(s)
- Hiranya Pintana
- Neurophysiology Unit, Cardiac Electrophysiology Research and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
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61
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Colciago A, Casati L, Negri-Cesi P, Celotti F. Learning and memory: Steroids and epigenetics. J Steroid Biochem Mol Biol 2015; 150:64-85. [PMID: 25766520 DOI: 10.1016/j.jsbmb.2015.02.008] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Revised: 02/11/2015] [Accepted: 02/12/2015] [Indexed: 12/19/2022]
Abstract
Memory formation and utilization is a complex process involving several brain structures in conjunction as the hippocampus, the amygdala and the adjacent cortical areas, usually defined as medial temporal lobe structures (MTL). The memory processes depend on the formation and modulation of synaptic connectivity affecting synaptic strength, synaptic plasticity and synaptic consolidation. The basic neurocognitive mechanisms of learning and memory are shortly recalled in the initial section of this paper. The effect of sex hormones (estrogens, androgens and progesterone) and of adrenocortical steroids on several aspects of memory processes are then analyzed on the basis of animal and human studies. A specific attention has been devoted to the different types of steroid receptors (membrane or nuclear) involved and on local metabolic transformations when required. The review is concluded by a short excursus on the steroid activated epigenetic mechanisms involved in memory formation.
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Affiliation(s)
- Alessandra Colciago
- Department of Pharmacological and Biomolecular Sciences, Section of Biomedicine and Endocrinology, Via Balzaretti 9, 20133 Milano, Italy
| | - Lavinia Casati
- Department of Medical Biotechnologies and Translational Medicine, Via Vanvitelli 32, 20129 Milano, Italy
| | - Paola Negri-Cesi
- Department of Pharmacological and Biomolecular Sciences, Section of Biomedicine and Endocrinology, Via Balzaretti 9, 20133 Milano, Italy
| | - Fabio Celotti
- Department of Pharmacological and Biomolecular Sciences, Section of Biomedicine and Endocrinology, Via Balzaretti 9, 20133 Milano, Italy
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Takanami K, Sakamoto H, Matsuda KI, Satoh K, Tanida T, Yamada S, Inoue K, Oti T, Sakamoto T, Kawata M. Distribution of gastrin-releasing peptide in the rat trigeminal and spinal somatosensory systems. J Comp Neurol 2014; 522:1858-73. [PMID: 24254931 DOI: 10.1002/cne.23506] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Revised: 08/30/2013] [Accepted: 11/15/2013] [Indexed: 12/12/2022]
Abstract
Gastrin-releasing peptide (GRP) has recently been identified as an itch-specific neuropeptide in the spinal sensory system in mice, but there are no reports of the expression and distribution of GRP in the trigeminal sensory system in mammals. We characterized and compared GRP-immunoreactive (ir) neurons in the trigeminal ganglion (TG) with those in the rat spinal dorsal root ganglion (DRG). GRP immunoreactivity was expressed in 12% of TG and 6% of DRG neurons and was restricted to the small- and medium-sized type cells. In both the TG and DRG, many GRP-ir neurons also expressed substance P and calcitonin gene-related peptide, but not isolectin B4 . The different proportions of GRP and transient receptor potential vanilloid 1 double-positive neurons in the TG and DRG imply that itch sensations via the TG and DRG pathways are transmitted through distinct mechanisms. The distribution of the axon terminals of GRP-ir primary afferents and their synaptic connectivity with the rat trigeminal sensory nuclei and spinal dorsal horn were investigated by using light and electron microscopic histochemistry. Although GRP-ir fibers were rarely observed in the trigeminal sensory nucleus principalis, oralis, and interpolaris, they were predominant in the superficial layers of the trigeminal sensory nucleus caudalis (Vc), similar to the spinal dorsal horn. Ultrastructural analysis revealed that GRP-ir terminals contained clear microvesicles and large dense-cored vesicles, and formed asymmetric synaptic contacts with a few dendrites in the Vc and spinal dorsal horn. These results suggest that GRP-dependent orofacial and spinal pruriceptive inputs are processed mainly in the superficial laminae of the Vc and spinal dorsal horn.
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Affiliation(s)
- Keiko Takanami
- Department of Anatomy and Neurobiology, Kyoto Prefectural University of Medicine, Kawaramachi-Hirokoji, Kamigyo-ku, Kyoto, 602-8566, Japan
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63
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Atwi S, McMahon D, Scharfman H, MacLusky NJ. Androgen Modulation of Hippocampal Structure and Function. Neuroscientist 2014; 22:46-60. [PMID: 25416742 DOI: 10.1177/1073858414558065] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Androgens have profound effects on hippocampal structure and function, including induction of spines and spine synapses on the dendrites of CA1 pyramidal neurons, as well as alterations in long-term synaptic plasticity (LTP) and hippocampally dependent cognitive behaviors. How these effects occur remains largely unknown. Emerging evidence, however, suggests that one of the key elements in the response mechanism may be modulation of brain-derived neurotrophic factor (BDNF) in the mossy fiber (MF) system. In male rats, orchidectomy increases synaptic transmission and excitability in the MF pathway. Testosterone reverses these effects, suggesting that testosterone exerts tonic suppression on MF BDNF levels. These findings suggest that changes in hippocampal function resulting from declining androgen levels may reflect the outcome of responses mediated through normally balanced, but opposing, mechanisms: loss of androgen effects on the hippocampal circuitry may be compensated, at least in part, by an increase in BDNF-dependent MF plasticity.
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Affiliation(s)
- Sarah Atwi
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, Ontario, Canada
| | - Dallan McMahon
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, Ontario, Canada
| | - Helen Scharfman
- The Nathan Kline Institute for Psychiatric Research, Orangeburg, NY, USA Department of Child & Adolescent Psychiatry, Physiology & Neuroscience, and Psychiatry, New York University Langone Medical Center, New York, NY, USA
| | - Neil J MacLusky
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, Ontario, Canada
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64
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Sexual neurosteroids and synaptic plasticity in the hippocampus. Brain Res 2014; 1621:162-9. [PMID: 25452021 DOI: 10.1016/j.brainres.2014.10.033] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Accepted: 10/18/2014] [Indexed: 11/23/2022]
Abstract
Sexual neurosteroids (SN), namely 17β-estradiol (E2) and 5α-dehydrotestosterone (DHT), are synthesized in the hippocampus, where they induce circuit modifications by changing the number of excitatory spine synapses in a paracrine and sex-specific manner. The mechanisms of this sex-specific synapse turnover, which are likely to affect cognitive functions, are poorly understood. We found that hippocampal neurons synthesize estradiol, which maintains LTP and synapses in females but not in males. In females, inhibition of estradiol synthesis results in impairment of LTP and synapse loss. These effects were not seen in males. The essential role of local estrogen on the stability and maintenance of connectivity in the hippocampus is consistent with age-related cognitive decline in women after menopause. In male animals the regulation of synaptic stability and plasticity by locally synthesized sexual steroids remains to be clarified. This article is part of a Special Issue entitled SI: Brain and Memory.
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65
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Protective effects of testosterone on presynaptic terminals against oligomeric β-amyloid peptide in primary culture of hippocampal neurons. BIOMED RESEARCH INTERNATIONAL 2014; 2014:103906. [PMID: 25045655 PMCID: PMC4086619 DOI: 10.1155/2014/103906] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/15/2014] [Revised: 05/14/2014] [Accepted: 05/14/2014] [Indexed: 12/12/2022]
Abstract
Increasing lines of evidence support that testosterone may have neuroprotective effects. While observational studies reported an association between higher bioavailable testosterone or brain testosterone levels and reduced risk of Alzheimer's disease (AD), there is limited understanding of the underlying neuroprotective mechanisms. Previous studies demonstrated that testosterone could alleviate neurotoxicity induced by β-amyloid (Aβ), but these findings mainly focused on neuronal apoptosis. Since synaptic dysfunction and degeneration are early events during the pathogenesis of AD, we aim to investigate the effects of testosterone on oligomeric Aβ-induced synaptic changes. Our data suggested that exposure of primary cultured hippocampal neurons to oligomeric Aβ could reduce the length of neurites and decrease the expression of presynaptic proteins including synaptophysin, synaptotagmin, and synapsin-1. Aβ also disrupted synaptic vesicle recycling and protein folding machinery. Testosterone preserved the integrity of neurites and the expression of presynaptic proteins. It also attenuated Aβ-induced impairment of synaptic exocytosis. By using letrozole as an aromatase antagonist, we further demonstrated that the effects of testosterone on exocytosis were unlikely to be mediated through the estrogen receptor pathway. Furthermore, we showed that testosterone could attenuate Aβ-induced reduction of HSP70, which suggests a novel mechanism that links testosterone and its protective function on Aβ-induced synaptic damage. Taken together, our data provide further evidence on the beneficial effects of testosterone, which may be useful for future drug development for AD.
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66
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Jayaraman A, Christensen A, Moser VA, Vest RS, Miller CP, Hattersley G, Pike CJ. Selective androgen receptor modulator RAD140 is neuroprotective in cultured neurons and kainate-lesioned male rats. Endocrinology 2014; 155:1398-406. [PMID: 24428527 PMCID: PMC3959610 DOI: 10.1210/en.2013-1725] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The decline in testosterone levels in men during normal aging increases risks of dysfunction and disease in androgen-responsive tissues, including brain. The use of testosterone therapy has the potential to increase the risks for developing prostate cancer and or accelerating its progression. To overcome this limitation, novel compounds termed "selective androgen receptor modulators" (SARMs) have been developed that lack significant androgen action in prostate but exert agonist effects in select androgen-responsive tissues. The efficacy of SARMs in brain is largely unknown. In this study, we investigate the SARM RAD140 in cultured rat neurons and male rat brain for its ability to provide neuroprotection, an important neural action of endogenous androgens that is relevant to neural health and resilience to neurodegenerative diseases. In cultured hippocampal neurons, RAD140 was as effective as testosterone in reducing cell death induced by apoptotic insults. Mechanistically, RAD140 neuroprotection was dependent upon MAPK signaling, as evidenced by elevation of ERK phosphorylation and inhibition of protection by the MAPK kinase inhibitor U0126. Importantly, RAD140 was also neuroprotective in vivo using the rat kainate lesion model. In experiments with gonadectomized, adult male rats, RAD140 was shown to exhibit peripheral tissue-specific androgen action that largely spared prostate, neural efficacy as demonstrated by activation of androgenic gene regulation effects, and neuroprotection of hippocampal neurons against cell death caused by systemic administration of the excitotoxin kainate. These novel findings demonstrate initial preclinical efficacy of a SARM in neuroprotective actions relevant to Alzheimer's disease and related neurodegenerative diseases.
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Affiliation(s)
- Anusha Jayaraman
- Davis School of Gerontology (A.J., A.C., R.S.V., C.J.P.) and Neuroscience Graduate Program (V.A.M., C.J.P.), University of Southern California, Los Angeles, California 90089; and Radius Health, Inc. (C.P.M., G.H.), Cambridge, Massachusetts 02139
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67
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Garelick T, Swann J. Testosterone regulates the density of dendritic spines in the male preoptic area. Horm Behav 2014; 65:249-53. [PMID: 24492023 DOI: 10.1016/j.yhbeh.2014.01.008] [Citation(s) in RCA: 20] [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: 10/05/2013] [Revised: 01/17/2014] [Accepted: 01/26/2014] [Indexed: 11/29/2022]
Abstract
Male-typical behavior is dependent on testosterone. Castrated males gradually stop mating and engaging in sexual behaviors. Castrates treated with testosterone regain motivation and sex behaviors over time. Although this effect is well characterized, the specific mechanisms by which testosterone treatment recovers sexual behaviors remain unknown. The medial preoptic area (MPOA) is a likely site for testosterone's action on copulation. The integrity of the area is essential for the expression of male sex behavior; and the MPOA is densely populated with receptors for gonadal steroids. Moreover testosterone appears to regulate synaptic efficacy in the MPOA. Exposure to sexually relevant stimuli stimulates the MPOA but only in the presence of circulating testosterone. Sites afferent to the area respond to similar exposure independent of the hormonal milieu suggesting that testosterone mediates communication between the MPOA and its afferents. The protracted time course suggests that the effects of steroidal manipulation are mediated by structural changes. The present experiment evaluated this hypothesis by comparing dendritic spine density among Syrian hamsters that were castrated, castrated and treated with testosterone, or were left gonadally intact. Brains were sectioned and stained using the rapid Golgi stain protocol (FD Neurotechnologies, Baltimore), and the spine density, dendrite length, and the number of branches were compared among groups. Intact and testosterone replaced animals had more spines and greater spine density but did not differ in dendrite length and branching from castrated animals. These results suggest that existing dendrites increase the number of spines available for synapse formation but do not extend their dendrites in response to testosterone treatment.
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Affiliation(s)
- Timothy Garelick
- Lehigh University, Iacocca Hall, 111 Research Dr., Bethlehem, PA 18015, United States.
| | - Jennifer Swann
- Lehigh University, Iacocca Hall, 111 Research Dr., Bethlehem, PA 18015, United States.
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68
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Fanaei H, Karimian SM, Sadeghipour HR, Hassanzade G, Kasaeian A, Attari F, Khayat S, Ramezani V, Javadimehr M. Testosterone enhances functional recovery after stroke through promotion of antioxidant defenses, BDNF levels and neurogenesis in male rats. Brain Res 2014; 1558:74-83. [PMID: 24565925 DOI: 10.1016/j.brainres.2014.02.028] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Revised: 01/25/2014] [Accepted: 02/14/2014] [Indexed: 12/30/2022]
Abstract
It is reported that circulating testosterone levels decrease after cerebral ischemia. The aim of this study was to evaluate the effects of testosterone on oxidative stress, brain-derived neurotrophic factor (BDNF) levels, neurogenesis, histological damage and sensorimotor recovery in a castrated male rat model of focal cerebral ischemia. Animals were divided into four groups. For all animals, castrations were conducted 7 days before transient middle cerebral artery occlusion (MCAO) was done and cerebral ischemia was induced. The first group served as sham. Second was MCAO group and received vehicle only, third was MCAO group that was post-treated with testosterone and the fourth was MCAO group post-treated with testosterone and flutamide. Treatment only with testosterone significantly weakened oxidative stress and increased BDNF levels and sensorimotor recovery during a 10 days period. Rats receiving testosterone demonstrated a significant reduction in infarct volume and a significant increase in neurogenesis on 10th day after focal cerebral ischemia. Our results for the first time showed a potential advantageous effect of testosterone after cerebral ischemia in male rats, which was probably mediated by promoting antioxidant defenses, BDNF levels and neurogenesis.
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Affiliation(s)
- Hamed Fanaei
- Department of Physiology, School of Medicine, Zahedan University of Medical Sciences, Zahedan, Iran.
| | - Seyed Morteza Karimian
- Department of Physiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Hamid Reza Sadeghipour
- Department of Physiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Gholamreza Hassanzade
- Department of Anatomy, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran; Department of Neuroscience, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Amir Kasaeian
- Non-Communicable Diseases Research Center, Endocrinology and Metabolism Population Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran; Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Fatemeh Attari
- Department of Neuroscience, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Samira Khayat
- Nursing and Midwifery Faculty, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Vahid Ramezani
- Department of Pharmaceutics, Faculty of Pharmacy, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
| | - Mani Javadimehr
- Department of Medical English Language, School of Medicine, Zahedan University of Medical Sciences, Zahedan, Iran
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69
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Hawley WR, Grissom EM, Martin RC, Halmos MB, Bart CLS, Dohanich GP. Testosterone modulates spatial recognition memory in male rats. Horm Behav 2013; 63:559-65. [PMID: 23481590 DOI: 10.1016/j.yhbeh.2013.02.007] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2012] [Revised: 02/09/2013] [Accepted: 02/14/2013] [Indexed: 11/29/2022]
Abstract
A growing body of research indicates that testosterone influences spatial cognition in male rats; however, the overwhelming majority of studies have been conducted on tasks motivated by either food deprivation or water escape. The hippocampus-dependent version of the Y-maze task, which characterizes spatial recognition memory, capitalizes on the propensity of rats to gravitate toward novel spatial environments and is not contingent upon either appetite or the stress associated with water escape, two factors also affected by testosterone. Accordingly, the aim of the current study was to examine the effects of orchidectomy and subsequent testosterone treatment on spatial recognition memory. Orchidectomy did not impact spatial recognition memory when the delay between the information and retention trials of the Y-maze task was 24h. Alternatively, on the second Y-maze task, which featured a 48-h delay between trials, orchidectomy reduced, and treatments that produced higher levels of testosterone restored, preference for the arm associated with the novel spatial environment. Importantly, there were no differences in activity levels as a function of orchidectomy or testosterone treatment on either of the two tasks. Consistent with previous findings, orchidectomy attenuated, and testosterone treatment restored, both body weight gain and the relative weight of the androgen-sensitive ischiocavernosus muscle, which confirmed the efficacy of orchidectomy and testosterone treatments on physiological outcomes. Therefore, testosterone influenced spatial cognition on a task that minimized the influence of non-mnemonic factors and took advantage of the innate preference of rodents to seek out novel spatial environments.
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Affiliation(s)
- Wayne R Hawley
- Department of Psychology, Tulane University, New Orleans, LA 70118, USA.
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