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Auer MK, Joue G, Biedermann SV, Sommer T, Fuss J. The effect of short-term increase of estradiol levels on sexual desire and orgasm frequency in women and men: A double-blind, randomized, placebo-controlled trial. Psychoneuroendocrinology 2024; 160:106682. [PMID: 38056372 DOI: 10.1016/j.psyneuen.2023.106682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2022] [Revised: 11/15/2023] [Accepted: 11/19/2023] [Indexed: 12/08/2023]
Abstract
Estradiol (E2) has been implicated in sexual functioning in both sexes. E2 levels change distinctively over the menstrual cycle, peaking around ovulation. Data on short-term effects of fluctuating E2 levels on sexual desire are however sparse and mostly based on observational studies. To fill this gap, we ran a double-blind, randomized, placebo-controlled study (N = 126) to investigate the effects of a short-term increase in E2 on sexual desire and orgasm frequency in healthy, young men and women. Circulating E2 levels were elevated through estradiol valerate (E2V) administered over two consecutive days to simulate the rise in E2 levels around ovulation. E2V had no effect on orgasm frequency and only minor effects on sexual desire. On average, the administered E2V dampened change in sexual desire compared to untreated participants with comparable baseline sexual desire in such a way that sexual desire was slightly reduced even in those with higher baseline sexual desire. These findings suggest that short-term increases in E2 have little effect on sexual function and are unlikely to explain the increase in sexual desire around ovulation.
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Affiliation(s)
- Matthias K Auer
- Institute of Forensic Psychiatry and Sex Research, Center for Translational Neuro, and Behavioral Sciences, University of Duisburg-Essen, Essen, Germany
| | - Gina Joue
- Institute of Systems Neuroscience, Center of Experimental Medicine, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246 Hamburg, Germany
| | - Sarah V Biedermann
- Social and Emotional Neuroscience, Department of Psychiatry and Psychotherapy, Center of Psychosocial Medicine, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246 Hamburg, Germany
| | - Tobias Sommer
- Institute of Systems Neuroscience, Center of Experimental Medicine, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246 Hamburg, Germany
| | - Johannes Fuss
- Institute of Forensic Psychiatry and Sex Research, Center for Translational Neuro, and Behavioral Sciences, University of Duisburg-Essen, Essen, Germany.
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González-Flores O, Pfaus JG, Luna-Hernández A, Montes-Narváez O, Domínguez-Ordóñez R, Tecamachaltzi-Silvarán MB, García-Juárez M. Estradiol and progesterone-induced lordosis behavior is modulated by both the Kisspeptin receptor and melanin-concentrating hormone in estradiol benzoate-primed rats. Horm Behav 2022; 146:105257. [PMID: 36115135 DOI: 10.1016/j.yhbeh.2022.105257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 08/22/2022] [Accepted: 08/30/2022] [Indexed: 11/16/2022]
Abstract
Intracerebroventricular (ICV) administration of estradiol benzoate (E2B) and progesterone (P) induces intense lordosis behavior in ovariectomized rats primed peripherally with E2B. The present study tested the hypothesis that the Kisspeptin (Kiss) and melanin-concentrating hormone (MCH) pathways regulate female sexual behavior induced by these steroid hormones. In Experiment 1, we tested the relevance of the Kiss pathway by ICV infusion of its inhibitor, kiss-234, before administration of E2B or P in estrogen-primed rats. Lordosis induced by E2B alone or with the addition of P was reduced significantly at 30, 120, and 240 min. In Experiment 2, ICV infusion of MCH 30 min before E2B or P significantly reduced lordosis in rats primed with E2B alone. These data support the hypothesis that the Kiss and MCH pathways, which can release or modulate gonadotropin-releasing hormone (GnRH), are involved in E2B- and P-induced lordosis.
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Affiliation(s)
- Oscar González-Flores
- Centro de Investigación en Reproducción Animal, Universidad Autónoma de Tlaxcala-CINVESTAV, Tlaxcala, México
| | - James G Pfaus
- Department of Psychology and Life Sciences, Charles University, Prague, Czech Republic; Czech National Institute of Mental Health, Klecany, Czech Republic
| | - Ailyn Luna-Hernández
- Centro de Investigación en Reproducción Animal, Universidad Autónoma de Tlaxcala-CINVESTAV, Tlaxcala, México; Maestría en Ciencias Biológicas, Universidad Autónoma de Tlaxcala, Tlaxcala, México
| | - Omar Montes-Narváez
- Centro de Investigación en Reproducción Animal, Universidad Autónoma de Tlaxcala-CINVESTAV, Tlaxcala, México; Doctorado en Ciencias Biológicas, Universidad Autónoma de Tlaxcala, Tlaxcala, México
| | - Raymundo Domínguez-Ordóñez
- Centro de Investigación en Reproducción Animal, Universidad Autónoma de Tlaxcala-CINVESTAV, Tlaxcala, México; Licenciatura en Ingeniería Agronómica y Zootecnia, CRC, Benemérita Universidad Autónoma de Puebla, México
| | | | - Marcos García-Juárez
- Centro de Investigación en Reproducción Animal, Universidad Autónoma de Tlaxcala-CINVESTAV, Tlaxcala, México.
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Moeller JS, Bever SR, Finn SL, Phumsatitpong C, Browne MF, Kriegsfeld LJ. Circadian Regulation of Hormonal Timing and the Pathophysiology of Circadian Dysregulation. Compr Physiol 2022; 12:4185-4214. [PMID: 36073751 DOI: 10.1002/cphy.c220018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Circadian rhythms are endogenously generated, daily patterns of behavior and physiology that are essential for optimal health and disease prevention. Disruptions to circadian timing are associated with a host of maladies, including metabolic disease and obesity, diabetes, heart disease, cancer, and mental health disturbances. The circadian timing system is hierarchically organized, with a master circadian clock located in the suprachiasmatic nucleus (SCN) of the anterior hypothalamus and subordinate clocks throughout the CNS and periphery. The SCN receives light information via a direct retinal pathway, synchronizing the master clock to environmental time. At the cellular level, circadian rhythms are ubiquitous, with rhythms generated by interlocking, autoregulatory transcription-translation feedback loops. At the level of the SCN, tight cellular coupling maintains rhythms even in the absence of environmental input. The SCN, in turn, communicates timing information via the autonomic nervous system and hormonal signaling. This signaling couples individual cellular oscillators at the tissue level in extra-SCN brain loci and the periphery and synchronizes subordinate clocks to external time. In the modern world, circadian disruption is widespread due to limited exposure to sunlight during the day, exposure to artificial light at night, and widespread use of light-emitting electronic devices, likely contributing to an increase in the prevalence, and the progression, of a host of disease states. The present overview focuses on the circadian control of endocrine secretions, the significance of rhythms within key endocrine axes for typical, homeostatic functioning, and implications for health and disease when dysregulated. © 2022 American Physiological Society. Compr Physiol 12: 1-30, 2022.
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Affiliation(s)
- Jacob S Moeller
- Graduate Group in Endocrinology, University of California, Berkeley, California, USA
| | - Savannah R Bever
- Department of Psychology, University of California, Berkeley, California, USA
| | - Samantha L Finn
- Department of Psychology, University of California, Berkeley, California, USA
| | | | - Madison F Browne
- Department of Psychology, University of California, Berkeley, California, USA
| | - Lance J Kriegsfeld
- Graduate Group in Endocrinology, University of California, Berkeley, California, USA.,Department of Psychology, University of California, Berkeley, California, USA.,Department of Integrative Biology, University of California, Berkeley, California, USA.,The Helen Wills Neuroscience Institute, University of California, Berkeley, California, USA
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Bizzozzero-Hiriart M, Di Giorgio NP, Libertun C, Lux-Lantos VAR. GABAB Receptor Antagonism from Birth to Weaning Permanently Modifies Kiss1 Expression in the Hypothalamus and Gonads in Mice. Neuroendocrinology 2022; 112:998-1026. [PMID: 34963114 DOI: 10.1159/000521649] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2021] [Accepted: 12/22/2021] [Indexed: 11/19/2022]
Abstract
INTRODUCTION The kisspeptin gene Kiss1 is expressed in two hypothalamic areas: anteroventral periventricular nucleus/periventricular nucleus (AVPV/PeN) and arcuate nucleus (ARC), and also in gonads. Several pieces of evidence suggests that gamma-amino butyric acid B receptors (GABAB) signaling can regulate Kiss1 expression. Here, we inhibited GABAB signaling from PND2 to PND21 and evaluated the hypothalamic-pituitary-gonadal (HPG) axis. METHODS BALB/c mice were treated on postnatal days 2-21 (PND2-PND21) with CGP55845 (GABAB antagonist) and evaluated in PND21 and adulthood: gene expression (qPCR) in the hypothalamus and gonads, hormones by radioimmunoassay, gonad histochemistry (H&E), puberty onset, and estrous cycles. RESULTS At PND21, CGP inhibited Kiss1 and Tac2 and increased Pdyn and Gabbr1 in the ARC of both sexes and decreased Th only in female AVPV/PeN. Serum follicle-stimulating hormone (FSH) and testis weight were decreased in CGP-males, and puberty onset was delayed. In adults, Kiss1, Tac2, Pdyn, Pgr, Cyp19a1, and Gad1 were downregulated, while Gabbr1 was upregulated in the ARC of both sexes. In the AVPV/PeN, Kiss1, Th, Cyp19a1, and Pgr were decreased while Gad1 was increased in CGP-females, whereas Cyp19a1 was increased in CGP-males. Serum FSH was increased in CGP-males while prolactin was increased in CGP-females. Testosterone and progesterone were increased in ovaries from CGP-females, in which Kiss1, Cyp19a1, and Esr1 were downregulated while Hsd3b2 was upregulated, together with increased atretic and decreased ovulatory follicles. Testes from CGP-males showed decreased progesterone, increased Gabbr1, Kiss1, Kiss1r, and Esr2 and decreased Cyp19a1, and clear signs of seminiferous tubules atrophy. CONCLUSION These results demonstrate that appropriate GABAB signaling during this critical prepubertal period is necessary for the normal development of the HPG axis.
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Affiliation(s)
- Marianne Bizzozzero-Hiriart
- Laboratorio de Neuroendocrinología, Instituto de Biología y Medicina Experimental (IBYME-CONICET), Buenos Aires, Argentina
| | - Noelia P Di Giorgio
- Laboratorio de Neuroendocrinología, Instituto de Biología y Medicina Experimental (IBYME-CONICET), Buenos Aires, Argentina
| | - Carlos Libertun
- Laboratorio de Neuroendocrinología, Instituto de Biología y Medicina Experimental (IBYME-CONICET), Buenos Aires, Argentina
- Departamento de Fisiología, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Victoria A R Lux-Lantos
- Laboratorio de Neuroendocrinología, Instituto de Biología y Medicina Experimental (IBYME-CONICET), Buenos Aires, Argentina
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Lindo AN, Thorson JF, Bedenbaugh MN, McCosh RB, Lopez JA, Young SA, Meadows LJ, Bowdridge EC, Fergani C, Freking BA, Lehman MN, Hileman SM, Lents CA. Localization of kisspeptin, NKB, and NK3R in the hypothalamus of gilts treated with the progestin altrenogest. Biol Reprod 2021; 105:1056-1067. [PMID: 34037695 DOI: 10.1093/biolre/ioab103] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 05/17/2021] [Accepted: 05/21/2021] [Indexed: 11/12/2022] Open
Abstract
Mechanisms in the brain controlling secretion of gonadotropin hormones in pigs, particularly luteinizing hormone (LH), are poorly understood. Kisspeptin is a potent LH stimulant that is essential for fertility in many species, including pigs. Neurokinin B (NKB) acting through neurokinin 3 receptor (NK3R) is involved in kisspeptin-stimulated LH release, but organization of NKB and NK3R within the porcine hypothalamus is unknown. Hypothalamic tissue from ovariectomized (OVX) gilts was used to determine the distribution of immunoreactive kisspeptin, NKB, and NK3R cells in the arcuate nucleus (ARC). Almost all kisspeptin neurons coexpressed NKB in the porcine ARC. Immunostaining for NK3R was distributed throughout the preoptic area (POA) and in several hypothalamic areas including the periventricular and retrochiasmatic areas but was not detected within the ARC. There was no colocalization of NK3R with gonadotropin-releasing hormone (GnRH), but NK3R-positive fibers in the POA were in close apposition to GnRH neurons. Treating OVX gilts with the progestin altrenogest decreased LH pulse frequency and reduced mean circulating concentrations of LH compared with OVX control gilts (P < 0.01), but the number of kisspeptin and NKB cells in the ARC did not differ between treatments. The neuroanatomical arrangement of kisspeptin, NKB, and NK3R within the porcine hypothalamus confirm they are positioned to stimulate GnRH and LH secretion in gilts, though differences with other species exist. Altrenogest suppression of LH secretion in the OVX gilt does not appear to involve decreased peptide expression of kisspeptin or NKB.
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Affiliation(s)
- Ashley N Lindo
- Department of Physiology and Pharmacology and Department of Neuroscience, West Virginia University, Morgantown, WV, USA
| | | | - Michelle N Bedenbaugh
- Department of Physiology and Pharmacology and Department of Neuroscience, West Virginia University, Morgantown, WV, USA
| | - Richard B McCosh
- Department of Physiology and Pharmacology and Department of Neuroscience, West Virginia University, Morgantown, WV, USA
| | - Justin A Lopez
- Department of Physiology and Pharmacology and Department of Neuroscience, West Virginia University, Morgantown, WV, USA
| | - Samantha A Young
- Department of Physiology and Pharmacology and Department of Neuroscience, West Virginia University, Morgantown, WV, USA
| | - Lanny J Meadows
- Department of Physiology and Pharmacology and Department of Neuroscience, West Virginia University, Morgantown, WV, USA
| | - Elizabeth C Bowdridge
- Department of Physiology and Pharmacology and Department of Neuroscience, West Virginia University, Morgantown, WV, USA
| | - Chrysanthi Fergani
- Department of Neurobiology and Anatomical Sciences, The University of Mississippi Medical Center, Jackson, Miss., USA
| | | | - Michael N Lehman
- Department of Biological Sciences and the Brain Health Research Institute, Kent State University, Kent, OH, USA
| | - Stanley M Hileman
- Department of Physiology and Pharmacology and Department of Neuroscience, West Virginia University, Morgantown, WV, USA
| | - Clay A Lents
- USDA, ARS, U.S. Meat Animal Research Center, Clay Center, NE, USA
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Arrieta-Cruz I, Librado-Osorio R, Flores A, Mendoza-Garcés L, Chavira R, Cárdenas M, Gutiérrez-Juárez R, Domínguez R, Cruz ME. Estrogen Receptors Alpha and Beta in POA-AHA Region Regulate Asymmetrically Ovulation. Cell Mol Neurobiol 2019; 39:1139-1149. [PMID: 31250245 DOI: 10.1007/s10571-019-00708-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Accepted: 06/18/2019] [Indexed: 11/24/2022]
Abstract
We examined the role of the estrogen receptors alpha (ERα) and beta (ERβ) in of the preoptic-anterior hypothalamic area (POA-AHA) in the regulation of ovulation in rats. The number of ERα- and ERβ-immunoreactive (-ir) cells was determined at 09:00, 13:00, and 17:00 h of each stage of the estrous cycle in intact rats. Additionally, the effects of blocking ERα and ERβ on ovulation rate at 09:00 h on diestrus-2 or proestrus day through the microinjection of methyl-piperidino-pyrazole (MPP) or cyclofenil in either side of POA-AHA were evaluated. The number of ERα-ir and ERβ-ir cells in POA-AHA varied in each phase of estrous cycle. Either MPP or cyclofenil in the right side of POA-AHA on diestrus-2 day reduced the ovulation rate, while at proestrus day it was decreased in rats treated in either side with MPP, and in those treated with cyclofenil in the left side. MPP or cyclofenil produced a decrease in the surge of luteinizing hormone levels (LH) and an increase in progesterone and follicle stimulating hormone (FSH). Replacement with synthetic luteinizing hormone-releasing hormone in non-ovulating rats treated with MPP or cyclofenil restored ovulation. These results suggest that activation of estrogen receptors on the morning of diestrus-2 and proestrus day asymmetrically regulates ovulation and appropriately regulates the secretion of FSH and progesterone in the morning and afternoon of proestrus day. This ensures that both, the preovulatory secretion of LH and ovulation, occur at the right time.
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Affiliation(s)
- Isabel Arrieta-Cruz
- Department of Basic Research, National Institute of Geriatrics. Ministry of Health, Periférico Sur no. 2767, Col. San Jerónimo Lídice, La Magdalena Contreras, C.P. 10200, Ciudad De México, Mexico.
| | - Raúl Librado-Osorio
- Department of Basic Research, National Institute of Geriatrics. Ministry of Health, Periférico Sur no. 2767, Col. San Jerónimo Lídice, La Magdalena Contreras, C.P. 10200, Ciudad De México, Mexico
| | - Angélica Flores
- Reproductive Biology Research Unit, Neuroendocrinology Laboratory, Facultad de Estudios Superiores Zaragoza, UNAM, Col. Ejército de Oriente, Campus II, Batalla 5 de mayo s/n esquina, Iztapalapa, Fuerte De Loreto, C.P 09230, Mexico
| | - Luciano Mendoza-Garcés
- Department of Basic Research, National Institute of Geriatrics. Ministry of Health, Periférico Sur no. 2767, Col. San Jerónimo Lídice, La Magdalena Contreras, C.P. 10200, Ciudad De México, Mexico
| | - Roberto Chavira
- Department of Reproductive Biology, National Institute of Medical Sciences and Nutrition Salvador Zubirán, Ministry of Health, Mexico City, Mexico
| | - Mario Cárdenas
- Department of Reproductive Biology, National Institute of Medical Sciences and Nutrition Salvador Zubirán, Ministry of Health, Mexico City, Mexico
| | - Roger Gutiérrez-Juárez
- Department of Biomedical Sciences, School of Medicine, Facultad de Estudios Superiores Zaragoza, UNAM, Mexico City, Mexico
| | - Roberto Domínguez
- Reproductive Biology Research Unit, Neuroendocrinology Laboratory, Facultad de Estudios Superiores Zaragoza, UNAM, Col. Ejército de Oriente, Campus II, Batalla 5 de mayo s/n esquina, Iztapalapa, Fuerte De Loreto, C.P 09230, Mexico
| | - María-Esther Cruz
- Reproductive Biology Research Unit, Neuroendocrinology Laboratory, Facultad de Estudios Superiores Zaragoza, UNAM, Col. Ejército de Oriente, Campus II, Batalla 5 de mayo s/n esquina, Iztapalapa, Fuerte De Loreto, C.P 09230, Mexico.
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Marraudino M, Martini M, Trova S, Farinetti A, Ponti G, Gotti S, Panzica G. Kisspeptin system in ovariectomized mice: Estradiol and progesterone regulation. Brain Res 2018; 1688:8-14. [PMID: 29555237 DOI: 10.1016/j.brainres.2018.03.014] [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] [Received: 10/18/2017] [Revised: 02/12/2018] [Accepted: 03/10/2018] [Indexed: 12/26/2022]
Abstract
The kisspeptin system is clustered in two main groups of cell bodies (the periventricular region, RP3V and the arcuate nucleus, ARC) that send fibers mainly to the GnRH neurons and in a few other locations, including the paraventricular nucleus, PVN. In physiological conditions, gonadal hormones modulate the kisspeptin system with expression changes according to different phases of the estrous cycle: the highest being in estrus phase in RP3V and PVN (positive feedback), and in ARC during the diestrus phase (negative feedback). In this work we wanted to study these hormonal fluctuations during the estrous cycle, investigating the role played by progesterone (P) or estradiol (E2), alone or together, on the kisspeptin system. Gonadectomized CD1 female mice were treated with P, E2 or both (E2 + P), following a timing of administration that emulates the different phases of estrous cycle, for two cycles of 4 days. As expected, the two cell groups were differentially affected by E2; the RP3V group was positively influenced by E2 (alone or with the P), whereas in the ARC the administration of E2 did not affect the system. However P (alone) induced a rise in the kisspeptin immunoreactivity. All the treatments significantly affected the kisspeptin innervation of the PVN, with regional differences, suggesting that these fibers arrive from both RP3V and ARC nuclei.
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Affiliation(s)
- Marilena Marraudino
- Neuroscience Institute Cavalieri Ottolenghi (NICO), Regione Gonzole 10, Orbassano, Torino, Italy; Laboratory of Neuroendocrinology, Department of Neuroscience, Rita Levi Montalcini, University of Torino, Via Cherasco 15, Torino, Italy.
| | - Mariangela Martini
- Department of Biological Sciences, North Carolina State University, Raleigh, NC 27695-7614, United States
| | - Sara Trova
- Neuroscience Institute Cavalieri Ottolenghi (NICO), Regione Gonzole 10, Orbassano, Torino, Italy
| | - Alice Farinetti
- Neuroscience Institute Cavalieri Ottolenghi (NICO), Regione Gonzole 10, Orbassano, Torino, Italy; Laboratory of Neuroendocrinology, Department of Neuroscience, Rita Levi Montalcini, University of Torino, Via Cherasco 15, Torino, Italy
| | - Giovanna Ponti
- Neuroscience Institute Cavalieri Ottolenghi (NICO), Regione Gonzole 10, Orbassano, Torino, Italy; Department of Veterinary Sciences, University of Torino, Largo Braccini 2, Grugliasco, Torino, Italy
| | - Stefano Gotti
- Neuroscience Institute Cavalieri Ottolenghi (NICO), Regione Gonzole 10, Orbassano, Torino, Italy; Laboratory of Neuroendocrinology, Department of Neuroscience, Rita Levi Montalcini, University of Torino, Via Cherasco 15, Torino, Italy
| | - GianCarlo Panzica
- Neuroscience Institute Cavalieri Ottolenghi (NICO), Regione Gonzole 10, Orbassano, Torino, Italy; Laboratory of Neuroendocrinology, Department of Neuroscience, Rita Levi Montalcini, University of Torino, Via Cherasco 15, Torino, Italy
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Mohr MA, DonCarlos LL, Sisk CL. Inhibiting Production of New Brain Cells during Puberty or Adulthood Blunts the Hormonally Induced Surge of Luteinizing Hormone in Female Rats. eNeuro 2017; 4:ENEURO.0133-17.2017. [PMID: 29098175 PMCID: PMC5666323 DOI: 10.1523/eneuro.0133-17.2017] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Revised: 10/09/2017] [Accepted: 10/16/2017] [Indexed: 01/15/2023] Open
Abstract
New cells are added during both puberty and adulthood to hypothalamic regions that govern reproduction, homeostasis, and social behaviors, yet the functions of these late-born cells remain elusive. Here, we pharmacologically inhibited cell proliferation in ventricular zones during puberty or in adulthood and determined subsequent effects on the hormone-induced surge of luteinizing hormone (LH) in female rats. Initial neuroanatomical analyses focused on verifying incorporation, activation, and pharmacological inhibition of pubertally or adult born cells in the anteroventral periventricular nucleus (AVPV) of the hypothalamus because of the essential role of the AVPV in triggering the preovulatory LH surge in females. We first showed that approximately half of the pubertally born AVPV cells are activated by estradiol plus progesterone (P) treatment, as demonstrated by Fos expression, and that approximately 10% of pubertally born AVPV cells express estrogen receptor alpha (ERα). Next, we found that mitotic inhibition through intracerebroventricular (ICV) administration of cytosine β-D-arabinofuranoside (AraC), whether during puberty or in adulthood, decreased the number of new cells added to the AVPV and the suprachiasmatic nucleus (SCN), and also blunted and delayed the hormone-induced LH surge. These studies do not prove, but are highly suggestive, that ongoing postnatal addition of new cells in periventricular brain regions, including the AVPV and SCN, may be important to the integrity of female reproduction.
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Affiliation(s)
- Margaret A. Mohr
- Neuroscience Program, Michigan State University, East Lansing, MI 48824
| | - Lydia L. DonCarlos
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL 60153
| | - Cheryl L. Sisk
- Neuroscience Program, Michigan State University, East Lansing, MI 48824
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He W, Li X, Adekunbi D, Liu Y, Long H, Wang L, Lyu Q, Kuang Y, O'Byrne KT. Hypothalamic effects of progesterone on regulation of the pulsatile and surge release of luteinising hormone in female rats. Sci Rep 2017; 7:8096. [PMID: 28808344 PMCID: PMC5556103 DOI: 10.1038/s41598-017-08805-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Accepted: 07/12/2017] [Indexed: 01/10/2023] Open
Abstract
Progesterone can block the oestradiol-induced GnRH/LH surge and inhibit LH pulse frequency. Recent studies reported that progesterone prevented premature LH surges during ovarian hyperstimulation in women. As the most potent stimulator of GnRH/LH release, kisspeptin is believed to mediate the positive and negative feedback effects of oestradiol in the hypothalamic anteroventral periventricular (AVPV) and arcuate (ARC) nuclei, while the region-specific role of progesterone receptors in these nuclei remains unknown. This study examined the hypothesis that progesterone inhibits LH surge and pulsatile secretion via its receptor in the ARC and/or AVPV nuclei. Adult female rats received a single injection of pregnant mare serum gonadotropin followed by progesterone or vehicle. Progesterone administration resulted in a significant prolongation of the oestrous cycle and blockade of LH surge. However, microinjection of the progesterone receptor antagonist, RU486, into the AVPV reversed the prolonged cycle length and rescued the progesterone blockade LH surge, while RU486 into the ARC shortened LH pulse interval in the progesterone treated rats. These results demonstrated that progesterone's inhibitory effect on the GnRH/LH surge and pulsatile secretion is mediated by its receptor in the kisspeptin enriched hypothalamic AVPV and ARC respectively, which are essential for progesterone regulation of oestrous cyclicity in rats.
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Affiliation(s)
- Wen He
- Department of Assisted Reproduction, Shanghai Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, People's Republic of China
| | - Xiaofeng Li
- Division of Women's Health, Faculty of Life Sciences and Medicine, King's College London, Guy's Campus, London, UK
| | - Daniel Adekunbi
- Division of Women's Health, Faculty of Life Sciences and Medicine, King's College London, Guy's Campus, London, UK
| | - Yali Liu
- Department of Assisted Reproduction, Shanghai Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, People's Republic of China
| | - Hui Long
- Department of Assisted Reproduction, Shanghai Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, People's Republic of China
| | - Li Wang
- Department of Assisted Reproduction, Shanghai Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, People's Republic of China
| | - Qifeng Lyu
- Department of Assisted Reproduction, Shanghai Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, People's Republic of China
| | - Yanping Kuang
- Department of Assisted Reproduction, Shanghai Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, People's Republic of China.
| | - Kevin T O'Byrne
- Division of Women's Health, Faculty of Life Sciences and Medicine, King's College London, Guy's Campus, London, UK.
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Actions of Steroids: New Neurotransmitters. J Neurosci 2017; 36:11449-11458. [PMID: 27911748 DOI: 10.1523/jneurosci.2473-16.2016] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Revised: 08/30/2016] [Accepted: 09/09/2016] [Indexed: 02/07/2023] Open
Abstract
Over the past two decades, the classical understanding of steroid action has been updated to include rapid, membrane-initiated, neurotransmitter-like functions. While steroids were known to function on very short time spans to induce physiological and behavioral changes, the mechanisms by which these changes occur are now becoming more clear. In avian systems, rapid estradiol effects can be mediated via local alterations in aromatase activity, which precisely regulates the temporal and spatial availability of estrogens. Acute regulation of brain-derived estrogens has been shown to rapidly affect sensorimotor function and sexual motivation in birds. In rodents, estrogens and progesterone are critical for reproduction, including preovulatory events and female sexual receptivity. Membrane progesterone receptor as well as classical progesterone receptor trafficked to the membrane mediate reproductive-related hypothalamic physiology, via second messenger systems with dopamine-induced cell signals. In addition to these relatively rapid actions, estrogen membrane-initiated signaling elicits changes in morphology. In the arcuate nucleus of the hypothalamus, these changes are needed for lordosis behavior. Recent evidence also demonstrates that membrane glucocorticoid receptor is present in numerous cell types and species, including mammals. Further, membrane glucocorticoid receptor influences glucocorticoid receptor translocation to the nucleus effecting transcriptional activity. The studies presented here underscore the evidence that steroids behave like neurotransmitters to regulate CNS functions. In the future, we hope to fully characterize steroid receptor-specific functions in the brain.
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Vastagh C, Liposits Z. Impact of Proestrus on Gene Expression in the Medial Preoptic Area of Mice. Front Cell Neurosci 2017; 11:183. [PMID: 28725181 PMCID: PMC5495965 DOI: 10.3389/fncel.2017.00183] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Accepted: 06/15/2017] [Indexed: 11/13/2022] Open
Abstract
The antero-ventral periventricular zone (AVPV) and medial preoptic area (MPOA) have been recognized as gonadal hormone receptive regions of the rodent brain that-via wiring to gonadotropin-releasing hormone (GnRH) neurons-contribute to orchestration of the preovulatory GnRH surge. We hypothesized that neural genes regulating the induction of GnRH surge show altered expression in proestrus. Therefore, we compared the expression of 48 genes obtained from intact proestrous and metestrous mice, respectively, by quantitative real-time PCR (qPCR) method. Differential expression of 24 genes reached significance (p < 0.05). Genes upregulated in proestrus encoded neuropeptides (kisspeptin (KP), galanin (GAL), neurotensin (NT), cholecystokinin (CCK)), hormone receptors (growth hormone secretagogue receptor, μ-opioid receptor), gonadal steroid receptors (estrogen receptor alpha (ERα), progesterone receptor (PR), androgen receptor (AR)), solute carrier family proteins (vesicular glutamate transporter 2, vesicular monoamine transporter 2), proteins of transmitter synthesis (tyrosine hydroxylase (TH)) and transmitter receptor subunit (AMPA4), and other proteins (uncoupling protein 2, nuclear receptor related 1 protein). Proestrus evoked a marked downregulation of genes coding for adenosine A2a receptor, vesicular gamma-aminobutyric acid (GABA) transporter, 4-aminobutyrate aminotransferase, tachykinin precursor 1, NT receptor 3, arginine vasopressin receptor 1A, cannabinoid receptor 1, ephrin receptor A3 and aldehyde dehydrogenase 1 family, member L1. Immunocytochemistry was used to visualize the proteins encoded by Kiss1, Gal, Cck and Th genes in neuronal subsets of the AVPV/MPOA of the proestrous mice. The results indicate that gene expression of the AVPV/MPOA is significantly modified at late proestrus including genes that code for neuropeptides, gonadal steroid hormone receptors and synaptic vesicle transporters. These events support cellular and neuronal network requirements of the positive estradiol feedback action and contribute to preparation of the GnRH neuron system for the pre-ovulatory surge release.
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Affiliation(s)
- Csaba Vastagh
- Laboratory of Endocrine Neurobiology, Institute of Experimental Medicine, Hungarian Academy of SciencesBudapest, Hungary
| | - Zsolt Liposits
- Laboratory of Endocrine Neurobiology, Institute of Experimental Medicine, Hungarian Academy of SciencesBudapest, Hungary.,Department of Neuroscience, Faculty of Information Technology and Bionics, Pázmány Péter Catholic UniversityBudapest, Hungary
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Mittelman-Smith MA, Wong AM, Micevych PE. Estrogen and Progesterone Integration in an in vitro Model of RP3V Kisspeptin Neurons. Neuroendocrinology 2017; 106:101-115. [PMID: 28384629 PMCID: PMC5750133 DOI: 10.1159/000471878] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Accepted: 03/21/2017] [Indexed: 12/18/2022]
Abstract
Positive feedback on gonadotropin release requires not only estrogen but also progesterone to activate neural circuits. In rodents, ovarian estradiol (E2) stimulates progesterone synthesis in hypothalamic astrocytes (neuroP), needed for the luteinizing hormone (LH) surge. Kisspeptin (kiss) neurons are the principal stimulators of gonadotropin-releasing hormone neurons, and disruption of kiss signaling abrogates the LH surge. Similarly, blocking steroid synthesis in the hypothalamus or deleting classical progesterone receptor (PGR) selectively in kiss neurons prevents the LH surge. These results suggest a synergistic action of E2 and progesterone in kiss neurons to affect gonadotropin release. The mHypoA51, immortalized kiss-expressing neuronal cell line derived from adult female mice, is a tractable model for examining integration of steroid signaling underlying estrogen positive feedback. Here, we report that kiss neurons in vitro integrate E2 and progesterone signaling to increase levels of kiss translation and release. mHypoA51 neurons expressed nonclassical membrane progesterone receptors (mPRα and mPRβ) and E2-inducible PGR, required for progesterone-augmentation of E2-induced kiss expression. With astrocyte-conditioned media or in mHypoA51-astrocyte co-culture, neuroP augmented stimulatory effects of E2 on kiss protein. Progesterone activation of classical, membrane-localized PGR led to activation of MAPK and Src kinases. Importantly, progesterone or Src activation induced release of kiss from E2-primed mHypoA51 neurons. Consistent with previous studies, the present results provide compelling evidence that the interaction of E2 and progesterone stimulates kiss expression and release. Further, these results demonstrate a mechanism though which peripheral E2 may prime kiss neurons to respond to neuroP, mediating estrogen positive feedback.
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13
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Tanemura K, Ohtaki T, Kuwahara Y, Tsumagari S. Association between liver failure and hepatic UDP-glucuronosyltransferase activity in dairy cows with follicular cysts. J Vet Med Sci 2017; 79:86-91. [PMID: 27666462 PMCID: PMC5289243 DOI: 10.1292/jvms.15-0674] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Uridine 5’-diphospho-glucuronosyltransferase (UGT) liver activity was measured using estradiol-17β as a substrate in dairy cows with follicular cysts. The activity was significantly lower than that in dairy cows with normal estrous cycles (P<0.01). Liver disorders, such as fatty liver and hepatitis, were observed in half cows with follicular cysts, and liver UGT activity was lower than that in cows with normal estrus cycles. In addition, the liver UGT activity was significantly lower in dairy cows with follicular cysts without liver disorders than in dairy cows with normal estrous cycles. Therefore, the cows were divided into those with low, middle and high liver UGT activities, and liver disorder complication rates were investigated. The complication rate was significantly higher in the low- (78.1%) than in the middle- (22.2%) and high-level (8.3%) groups, suggesting that liver disorders are closely associated with the development of follicular cysts in dairy cows and that steroid hormone metabolism is delayed because of reduced liver UGT activity, resulting in follicular cyst formation. We conclude that reduced estradiol-17β glucuronidation in the liver and liver disorders are associated with follicular cyst occurrence in dairy cows.
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Affiliation(s)
- Kouichi Tanemura
- Laboratory of Theriogenology, College of Bioresouce Sciences, Nihon University, 1866 Kameino, Fujisawa, Kanagawa 252-0880, Japan
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14
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Mittelman-Smith MA, Rudolph LM, Mohr MA, Micevych PE. Rodent Models of Non-classical Progesterone Action Regulating Ovulation. Front Endocrinol (Lausanne) 2017; 8:165. [PMID: 28790975 PMCID: PMC5522857 DOI: 10.3389/fendo.2017.00165] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Accepted: 06/27/2017] [Indexed: 11/13/2022] Open
Abstract
It is becoming clear that steroid hormones act not only by binding to nuclear receptors that associate with specific response elements in the nucleus but also by binding to receptors on the cell membrane. In this newly discovered manner, steroid hormones can initiate intracellular signaling cascades which elicit rapid effects such as release of internal calcium stores and activation of kinases. We have learned much about the translocation and signaling of steroid hormone receptors from investigations into estrogen receptor α, which can be trafficked to, and signal from, the cell membrane. It is now clear that progesterone (P4) can also elicit effects that cannot be exclusively explained by transcriptional changes. Similar to E2 and its receptors, P4 can initiate signaling at the cell membrane, both through progesterone receptor and via a host of newly discovered membrane receptors (e.g., membrane progesterone receptors, progesterone receptor membrane components). This review discusses the parallels between neurotransmitter-like E2 action and the more recently investigated non-classical P4 signaling, in the context of reproductive behaviors in the rodent.
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Affiliation(s)
- Melinda A. Mittelman-Smith
- Department of Neurobiology, David Geffen School of Medicine at UCLA, The Laboratory of Neuroendocrinology, Brain Research Institute, University of California Los Angeles, Los Angeles, CA, United States
- *Correspondence: Melinda A. Mittelman-Smith,
| | - Lauren M. Rudolph
- Department of Neurobiology, David Geffen School of Medicine at UCLA, The Laboratory of Neuroendocrinology, Brain Research Institute, University of California Los Angeles, Los Angeles, CA, United States
| | - Margaret A. Mohr
- Department of Neurobiology, David Geffen School of Medicine at UCLA, The Laboratory of Neuroendocrinology, Brain Research Institute, University of California Los Angeles, Los Angeles, CA, United States
| | - Paul E. Micevych
- Department of Neurobiology, David Geffen School of Medicine at UCLA, The Laboratory of Neuroendocrinology, Brain Research Institute, University of California Los Angeles, Los Angeles, CA, United States
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Cox KH. A Kiss and a PRomise. Endocrinology 2015; 156:3063-5. [PMID: 26295491 PMCID: PMC4541626 DOI: 10.1210/en.2015-1602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- Kimberly H Cox
- Reproductive Endocrine Unit, Massachusetts General Hospital, Boston, Massachusetts 02114
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Mittelman-Smith MA, Wong AM, Kathiresan ASQ, Micevych PE. Classical and membrane-initiated estrogen signaling in an in vitro model of anterior hypothalamic kisspeptin neurons. Endocrinology 2015; 156:2162-73. [PMID: 25730107 PMCID: PMC4430613 DOI: 10.1210/en.2014-1803] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The neuropeptide kisspeptin is essential for sexual maturation and reproductive function. In particular, kisspeptin-expressing neurons in the anterior rostral periventricular area of the third ventricle are generally recognized as mediators of estrogen positive feedback for the surge release of LH, which stimulates ovulation. Estradiol induces kisspeptin expression in the neurons of the rostral periventricular area of the third ventricle but suppresses kisspeptin expression in neurons of the arcuate nucleus that regulate estrogen-negative feedback. To focus on the intracellular signaling and response to estradiol underlying positive feedback, we used mHypoA51 cells, an immortalized line of kisspeptin neurons derived from adult female mouse hypothalamus. mHypoA51 neurons express estrogen receptor (ER)-α, classical progesterone receptor (PR), and kisspeptin, all key elements of estrogen-positive feedback. As with kisspeptin neurons in vivo, 17β-estradiol (E2) induced kisspeptin and PR in mHypoA51s. The ERα agonist, 1,3,5-Tris(4-hydroxyphenyl)-4-propyl-1H-pyrazole, produced similar increases in expression, indicating that these events were mediated by ERα. However, E2-induced PR up-regulation required an intracellular ER, whereas kisspeptin expression was stimulated through a membrane ER activated by E2 coupled to BSA. These data suggest that anterior hypothalamic kisspeptin neurons integrate both membrane-initiated and classical nuclear estrogen signaling to up-regulate kisspeptin and PR, which are essential for the LH surge.
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Affiliation(s)
- Melinda A Mittelman-Smith
- David Geffen School of Medicine at University of California, Los Angeles, and Laboratory of Neuroendocrinology, Brain Research Institute, University of California, Los Angeles, Los Angeles, California 90095
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Dose-dependent effects of the antiprogestin, RU486, on sexual behavior of naturally cycling Fischer rats. Behav Brain Res 2015; 282:95-102. [PMID: 25591479 DOI: 10.1016/j.bbr.2015.01.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2014] [Revised: 01/01/2015] [Accepted: 01/05/2015] [Indexed: 11/22/2022]
Abstract
Regularly cycling Fischer female rats were treated with either a low (5mg/kg) or high (5mg/RAT; approximately 30mg/kg) dose of the antiprogestin, RU486, before the morning of proestrus or on the morning of proestrus. The emergence of sexual behavior after treatment with RU486 was examined in a mating test with a sexually active male rat. Lordosis behavior was remarkably resistant to the effects of RU486. Only the high dose of RU486 given the evening before proestrus, approximately 22h before mating, reduced lordosis behavior. Independent of dose or time of treatment, proceptivity was reduced and resistance to the male's attempts to mount was increased by RU486 treatment. In addition, the effect of a 5min restraint stress on sexual behavior was examined. In contrast to the relative resistance of lordosis behavior of unrestrained rats to RU486 treatment, RU486 treated rats showed a significant decline in lordosis behavior after restraint. These findings allow the suggestion that the emergence of lordosis behavior is relatively resistant to the antiprogestin while the maintenance of lordosis behavior after restraint may require participation of intracellular progesterone receptors.
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18
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Mouihate A. TLR4-mediated brain inflammation halts neurogenesis: impact of hormonal replacement therapy. Front Cell Neurosci 2014; 8:146. [PMID: 24904290 PMCID: PMC4034512 DOI: 10.3389/fncel.2014.00146] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2014] [Accepted: 05/07/2014] [Indexed: 12/27/2022] Open
Abstract
Experimental and epidemiological data show that the severity and the duration of brain inflammation are attenuated in females compared to males. This attenuated brain inflammation is ascribed to 17β-estradiol. However, several studies suggest that 17β-estradiol is also endowed with proinflammatory properties. The aim of the present study is to assess the effect of hormonal replacement therapies on lipopolysaccharide (LPS)-induced brain inflammation and its consequent effect on newly born neurons. Bilaterally ovariectomized rats received intrastriatal injection of LPS (250 ng/μl) and were subsequently given daily subcutaneous injections of either vehicle, 17β-estradiol (25 μg/kg) or 17β-estradiol and progesterone (5 mg/kg). Microglial activation and newly born neurons in the rostral migratory stream were monitored using double immunofluorescence. Nuclear factor κB (NFκB) signaling pathway and its target inflammatory proteins were assessed by either western blot [cyclooxygenase-2 (COX-2) and interleukin-6 (IL-6)] or enzyme-linked immunosorbent assay [tumor necrosis factor-α (TNF-α)]. LPS-induced activation of microglia, promoted NFκB signaling pathway and enhanced the production of proinflammatory proteins (TNF-α and COX-2). These proinflammatory responses were not attenuated by 17β-estradiol injection. Supplementation of 17β-estradiol with progesterone significantly dampened these proinflammatory processes. Interestingly, LPS-induced brain inflammation dampened the number of newly born neurons in the rostral migratory stream. Administration of combined 17β-estradiol and progesterone resulted in a significantly higher number of newly born neurons when compared to those seen in rats given either vehicle or 17β-estradiol alone. These data strongly suggest that combined 17β-estradiol and progesterone, and not 17β-estradiol alone, rescues neurogenesis from the deleterious effect of brain inflammation likely via the inhibition of the signaling pathways leading to the activation of proinflammatory genes.
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Affiliation(s)
- Abdeslam Mouihate
- Department of Physiology, Faculty of Medicine, Health Sciences Centre, Kuwait University Safat, Kuwait
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19
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Voigt C, Gahr M, Leitner S, Lutermann H, Bennett N. Breeding status and social environment differentially affect the expression of sex steroid receptor and aromatase mRNA in the brain of female Damaraland mole-rats. Front Zool 2014; 11:38. [PMID: 24839456 PMCID: PMC4024188 DOI: 10.1186/1742-9994-11-38] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Accepted: 05/01/2014] [Indexed: 11/21/2022] Open
Abstract
Introduction The Damaraland mole-rat (Fukomys damarensis) is a eusocial, subterranean mammal, which exhibits an extreme reproductive skew with a single female (queen) monopolizing reproduction in each colony. Non-reproductive females in the presence of the queen are physiologically suppressed to the extent that they are anovulatory. This blockade is thought to be caused by a disruption in the normal gonadotropin-releasing hormone (GnRH) secretion from the hypothalamus. In order to understand the underlying physiological mechanisms of reproductive suppression in subordinate females we studied the expression of steroid hormone receptors and the androgen-converting enzyme aromatase in forebrain regions involved in the control of reproductive behaviour in female breeders and non-breeders from intact colonies. Additionally, we included in our analysis females that experienced the release from social suppression by being removed from the presence of the queen. Results We found expression of androgen receptor, estrogen receptor α and aromatase in several forebrain regions of female Damaraland mole-rats. Their distribution matches previous findings in other mammals. Quantification of the hybridisation signal revealed that queens had increased expression of androgen receptors compared to non-breeders and removed non-breeders in most brain regions examined, which include the medial preoptic area (MPOA), the principal nucleus of the bed nucleus of the stria terminalis (BSTp), the ventromedial nucleus of the hypothalamus (VMH), the arcuate nucleus (ARC) and the medial amygdala (MeA). Furthermore, breeders had increased estrogen receptor α expression in the anteroventral periventricular nucleus (AVPV) and in the MeA, while aromatase expression in the AVPV was significantly reduced compared to non-breeders. Absence of social suppression was associated with increased androgen receptor expression in the ARC, increased estrogen receptor α expression in the MeA and BSTp and reduced aromatase expression in the AVPV. Conclusion This study shows that social suppression and breeding differentially affect the neuroendocrine phenotype of female Damaraland mole-rats. The differential expression pattern of estrogen receptor α and aromatase in the AVPV between breeders and non-breeders supports the view that this region plays an important role in mediating the physiological suppression in subordinate females.
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Affiliation(s)
- Cornelia Voigt
- Department of Zoology and Entomology, University of Pretoria, 0028 Pretoria, South Africa
| | - Manfred Gahr
- Department of Behavioural Neurobiology, Max Planck Institute for Ornithology, D-82319 Seewiesen, Germany
| | - Stefan Leitner
- Department of Behavioural Neurobiology, Max Planck Institute for Ornithology, D-82319 Seewiesen, Germany
| | - Heike Lutermann
- Department of Zoology and Entomology, University of Pretoria, 0028 Pretoria, South Africa
| | - Nigel Bennett
- Department of Zoology and Entomology, University of Pretoria, 0028 Pretoria, South Africa
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20
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Harrell CS, Burgado J, Kelly SD, Neigh GN. Ovarian steroids influence cerebral glucose transporter expression in a region- and isoform-specific pattern. J Neuroendocrinol 2014; 26:217-25. [PMID: 24612045 PMCID: PMC5688845 DOI: 10.1111/jne.12139] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2013] [Revised: 01/15/2014] [Accepted: 02/22/2014] [Indexed: 02/05/2023]
Abstract
Cerebral glucose uptake is mediated by several members of the family of facilitated glucose transporters (protein nomenclature GLUT; gene nomenclature solute carrier family 2 Slc2a). Glucose uptake differs between the sexes and also varies with menstrual status in women and across the rodent oestrous cycle. The present study demonstrates the extent to which hormonal variation across the four stages of the rat oestrous cycle affects the mRNA abundance of four members of the GLUT family, including the most well characterised cerebral transporters Slc2a1 and Slc2a3, as well as the insulin-sensitive transporters Slc2a4 and Slc2a8 in the hypothalamus, hippocampus and prefrontal cortex. Slc2a1 varied significantly across the cycle in the hippocampus and prefrontal cortex, and Slc2a3 and Slc2a4 also showed significant fluctuation in the hippocampus. Transporter expression significantly increased during pro-oestrus in both the hippocampus and prefrontal cortex. Furthermore, ovarian hormones are critical for normal expression of GLUT mRNA, as demonstrated by reduced expression of Slc2a1, Slc2a3 and Sl2a8 in the hippocampus after ovariectomy. Collectively, the data reported in the present study demonstrate that glucose transporters are highly sensitive to hormonal variation and that this sensitivity is regionally distinct; thereby fluctuations likely have specific phenotypic implications.
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Affiliation(s)
- C S Harrell
- Department of Physiology, Emory University, Atlanta, GA, USA
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21
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Frazao R, Dungan Lemko HM, da Silva RP, Ratra DV, Lee CE, Williams KW, Zigman JM, Elias CF. Estradiol modulates Kiss1 neuronal response to ghrelin. Am J Physiol Endocrinol Metab 2014; 306:E606-14. [PMID: 24473434 PMCID: PMC3948981 DOI: 10.1152/ajpendo.00211.2013] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Ghrelin is a metabolic signal regulating energy homeostasis. Circulating ghrelin levels rise during starvation and fall after a meal, and therefore, ghrelin may function as a signal of negative energy balance. Ghrelin may also act as a modulator of reproductive physiology, as acute ghrelin administration suppresses gonadotropin secretion and inhibits the neuroendocrine reproductive axis. Interestingly, ghrelin's effect in female metabolism varies according to the estrogen milieu predicting an interaction between ghrelin and estrogens, likely at the hypothalamic level. Here, we show that ghrelin receptor (GHSR) and estrogen receptor-α (ERα) are coexpressed in several hypothalamic sites. Higher levels of circulating estradiol increased the expression of GHSR mRNA and the coexpression of GHSR mRNA and ERα selectively in the arcuate nucleus (ARC). Subsets of preoptic and ARC Kiss1 neurons coexpressed GHSR. Increased colocalization was observed in ARC Kiss1 neurons of ovariectomized estradiol-treated (OVX + E₂; 80%) compared with ovariectomized oil-treated (OVX; 25%) mice. Acute actions of ghrelin on ARC Kiss1 neurons were also modulated by estradiol; 75 and 22% of Kiss1 neurons of OVX + E₂ and OVX mice, respectively, depolarized in response to ghrelin. Our findings indicate that ghrelin and estradiol may interact in several hypothalamic sites. In the ARC, high levels of E₂ increase GHSR mRNA expression, modifying the colocalization rate with ERα and Kiss1 and the proportion of Kiss1 neurons acutely responding to ghrelin. Our findings indicate that E₂ alters the responsiveness of kisspeptin neurons to metabolic signals, potentially acting as a critical player in the metabolic control of the reproductive physiology.
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Affiliation(s)
- Renata Frazao
- Department of Internal Medicine, Division of Hypothalamic Research, University of Texas Southwestern Medical Center, Dallas, Texas
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22
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Petersen SL, Intlekofer KA, Moura-Conlon PJ, Brewer DN, Del Pino Sans J, Lopez JA. Novel progesterone receptors: neural localization and possible functions. Front Neurosci 2013; 7:164. [PMID: 24065878 PMCID: PMC3776953 DOI: 10.3389/fnins.2013.00164] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2013] [Accepted: 08/24/2013] [Indexed: 12/30/2022] Open
Abstract
Progesterone (P4) regulates a wide range of neural functions and likely acts through multiple receptors. Over the past 30 years, most studies investigating neural effects of P4 focused on genomic and non-genomic actions of the classical progestin receptor (PGR). More recently the focus has widened to include two groups of non-classical P4 signaling molecules. Members of the Class II progestin and adipoQ receptor (PAQR) family are called membrane progestin receptors (mPRs) and include: mPRα (PAQR7), mPRβ (PAQR8), mPRγ (PAQR5), mPRδ (PAQR6), and mPRε (PAQR9). Members of the b5-like heme/steroid-binding protein family include progesterone receptor membrane component 1 (PGRMC1), PGRMC2, neudesin, and neuferricin. Results of our recent mapping studies show that members of the PGRMC1/S2R family, but not mPRs, are quite abundant in forebrain structures important for neuroendocrine regulation and other non-genomic effects of P4. Herein we describe the structures, neuroanatomical localization, and signaling mechanisms of these molecules. We also discuss possible roles for Pgrmc1/S2R in gonadotropin release, feminine sexual behaviors, fluid balance and neuroprotection, as well as catamenial epilepsy.
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Affiliation(s)
- Sandra L Petersen
- Molecular and Cellular Neuroendocrinology, Department of Veterinary and Animal Sciences, University of Massachusetts Amherst Amherst, MA, USA
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Wang Y, Xu L, Pan Y, Wang Z, Zhang Z. Species differences in the immunoreactive expression of oxytocin, vasopressin, tyrosine hydroxylase and estrogen receptor alpha in the brain of Mongolian gerbils (Meriones unguiculatus) and Chinese striped hamsters (Cricetulus barabensis). PLoS One 2013; 8:e65807. [PMID: 23762431 PMCID: PMC3676338 DOI: 10.1371/journal.pone.0065807] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Accepted: 04/28/2013] [Indexed: 01/21/2023] Open
Abstract
Species differences in neurochemical expression and activity in the brain may play an important role in species-specific patterns of social behavior. In the present study, we used immunoreactive (ir) labeling to compare the regional density of cells containing oxytocin (OT), vasopressin (AVP), tyrosine hydroxylase (TH), or estrogen receptor alpha (ERα) staining in the brains of social Mongolian gerbils (Meriones unguiculatus) and solitary Chinese striped hamsters (Cricetulus barabensis). Multiple region- and neurochemical-specific species differences were found. In the anterior hypothalamus (AH), Mongolian gerbils had higher densities of AVP-ir and ERα-ir cells than Chinese striped hamsters. In the lateral hypothalamus (LH), Mongolian gerbils also had higher densities of AVP-ir and TH-ir cells, but a lower density of OT-ir cells, than Chinese striped hamsters. Furthermore, in the anterior nucleus of the medial preoptic area (MPOAa), Mongolian gerbils had higher densities of OT-ir and AVP-ir cells than Chinese striped hamsters, and an opposite pattern was found in the posterior nucleus of the MPOA (MPOAp). Some sex differences were also observed. Females of both species had higher densities of TH-ir cells in the MPOAa and of OT-ir cells in the intermediate nucleus of the MPOA (MPOAi) than males. Given the role of these neurochemicals in social behaviors, our data provide additional evidence to support the notion that species-specific patterns of neurochemical expression in the brain may be involved in species differences in social behaviors associated with different life strategies.
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Affiliation(s)
- Yu Wang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture, Institute of Zoology, Chinese Academy of Sciences, Beijing, PR China
- University of Chinese Academy of Sciences, Beijing, PR China
| | - Linxi Xu
- State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture, Institute of Zoology, Chinese Academy of Sciences, Beijing, PR China
- University of Chinese Academy of Sciences, Beijing, PR China
| | - Yongliang Pan
- State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture, Institute of Zoology, Chinese Academy of Sciences, Beijing, PR China
| | - Zuoxin Wang
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, Florida, United States of America
| | - Zhibin Zhang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture, Institute of Zoology, Chinese Academy of Sciences, Beijing, PR China
- * E-mail:
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Donato J, Lee C, Ratra DV, Franci CR, Canteras NS, Elias CF. Lesions of the ventral premammillary nucleus disrupt the dynamic changes in Kiss1 and GnRH expression characteristic of the proestrus-estrus transition. Neuroscience 2013; 241:67-79. [PMID: 23518222 DOI: 10.1016/j.neuroscience.2013.03.013] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2012] [Revised: 02/20/2013] [Accepted: 03/08/2013] [Indexed: 11/16/2022]
Abstract
We have recently demonstrated that the ventral premammillary nucleus (PMV) plays a key role in the metabolic control of the female reproductive axis. However, whether PMV neurons modulate the reproductive neural circuitry and/or the expression of sexual behaviors has not been determined. Here, we showed that the expression of estrogen and progesterone receptors in the PMV is modulated by changing levels of sex steroids across the estrous cycle. We also showed that sexual behavior, not the high physiologic levels of sex steroids, induces Fos in PMV neurons. Bilateral lesions of the PMV caused no significant changes in proceptive behavior but a high percentage of PMV-lesioned rats failed to exhibit lordosis behavior when exposed to a sexually experienced male rat (50% vs. 18% in the control group). Notably, lesions of the PMV disrupted the physiologic fluctuations of Kiss1 and GnRH mRNA expression characteristic of the proestrus-to-estrus transition. This neurochemical imbalance may ultimately alter female reproductive behavior. Our findings suggest that the PMV is a component of the neural circuitry that modulates the physiologic fluctuations of key neuroendocrine players (i.e., Kiss1 and GnRH) in the control of the female reproductive physiology.
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Affiliation(s)
- J Donato
- Department of Internal Medicine, Division of Hypothalamic Research, University of Texas Southwestern Medical Center, Dallas, TX, USA
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Williams B, Northcutt KV, Rusanowsky RD, Mennella TA, Lonstein JS, Quadros-Mennella PS. Progesterone receptor expression in the brain of the socially monogamous and paternal male prairie vole. Brain Res 2013; 1499:12-20. [PMID: 23318255 DOI: 10.1016/j.brainres.2013.01.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2012] [Revised: 01/04/2013] [Accepted: 01/05/2013] [Indexed: 11/28/2022]
Abstract
Differences in the social organization and behavior of male mammals are attributable to species differences in neurochemistry, including differential expression of steroid hormone receptors. However, the distribution of progestin receptors (PR) in a socially monogamous and spontaneously parental male rodent has never been examined. Here we determined if PR exists and is regulated by testicular hormones in forebrain sites traditionally influencing socioreproductive behaviors in male prairie voles (Microtus ochrogaster). We hypothesized that PR expression in male prairie voles would differ from that described in other male rodents because PR activity inhibits parental behaviors and social memory in laboratory mice and rats. Adult male prairie voles received a sham surgery, were gonadectomized, or were gonadectomized and implanted with a testosterone-filled capsule. PR immunoreactivity (PRir) was measured four weeks later in areas of the hypothalamus and extended amygdala. A group of gonadally intact female prairie voles was included to reveal possible sex differences. We found considerable PRir in all sites examined. Castration reduced PRir in males' medial preoptic nucleus, anteroventral periventricular nucleus, ventromedial hypothalamus, and posterodorsal medial amygdala, and it was maintained in these sites by testosterone. This is the first study to examine PR expression in brain sites involved in socioreproductive behaviors in a socially monogamous and spontaneously paternal male rodent. Our results mostly reveal cross-species conservation in the distribution and hormone sensitivity of PR expression. Because PR interferes with aspects of sociality in other male rodents, PR may eventually be found to have different neurobiological actions in male prairie voles.
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Affiliation(s)
- Brittany Williams
- Department of Biological Sciences, 1200N Dupont Hwy, Delaware State University, Dover, DE 19901, USA
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Petersen SL, Krishnan S, Aggison LK, Intlekofer KA, Moura PJ. Sexual differentiation of the gonadotropin surge release mechanism: a new role for the canonical NfκB signaling pathway. Front Neuroendocrinol 2012; 33:36-44. [PMID: 21741397 DOI: 10.1016/j.yfrne.2011.06.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2011] [Revised: 06/09/2011] [Accepted: 06/11/2011] [Indexed: 12/30/2022]
Abstract
Sex differences in luteinizing hormone (LH) release patterns are controlled by the hypothalamus, established during the perinatal period and required for fertility. Female mammals exhibit a cyclic surge pattern of LH release, while males show a tonic release pattern. In rodents, the LH surge pattern is dictated by the anteroventral periventricular nucleus (AVPV), an estrogen receptor-rich structure that is larger and more cell-dense in females. Sex differences result from mitochondrial cell death triggered in perinatal males by estradiol derived from aromatization of testosterone. Herein we provide an historical perspective and an update describing evidence that molecules important for cell survival and cell death in the immune system also control these processes in the developing AVPV. We conclude with a new model proposing that development of the female AVPV requires constitutive activation of the Tnfα, Tnf receptor 2, NfκB and Bcl2 pathway that is blocked by induction of Tnf receptor-associated factor 2-inhibiting protein (Traip) in the male.
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Affiliation(s)
- Sandra L Petersen
- Department of Veterinary and Animal Sciences, University of Massachusetts Amherst, Amherst, MA 01003, United States.
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Comparative distribution of cocaine- and amphetamine-regulated transcript (CART) in the hypothalamus of the capuchin monkey (Cebus apella) and the common marmoset (Callithrix jacchus). Brain Res 2011; 1425:47-61. [DOI: 10.1016/j.brainres.2011.09.020] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2011] [Revised: 08/27/2011] [Accepted: 09/10/2011] [Indexed: 11/17/2022]
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Sun Y, Todd BJ, Thornton K, Etgen AM, Neal-Perry G. Differential effects of hypothalamic IGF-I on gonadotropin releasing hormone neuronal activation during steroid-induced LH surges in young and middle-aged female rats. Endocrinology 2011; 152:4276-87. [PMID: 21914776 PMCID: PMC3199007 DOI: 10.1210/en.2011-1051] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Interactions between brain IGF-I receptors and estrogen receptors regulate female reproductive physiology and behavior. The present study investigated potential mechanisms by which IGF-I receptors in the neuroendocrine hypothalamus regulate GnRH neuronal activation and LH release in young and middle-aged female rats under estradiol (E2) positive feedback conditions. We infused vehicle, IGF-I, or JB-1, a selective antagonist of IGF-I receptors, into the third ventricle of ovariectomized female rats primed with E2 and progesterone or vehicle. In young females, blockade of IGF-I receptors attenuated the steroid hormone-induced LH surge, reduced the percent of GnRH neurons expressing c-fos on the day of the LH surge, and decreased the total number of neurons expressing c-fos in the preoptic area. Middle-aged females had fewer GnRH neurons expressing c-fos during the LH surge than young females, and the LH surge amplitude was attenuated. Infusion of an IGF-I dose previously shown to increase LH surge amplitude did not increase the percent of GnRH neurons expressing c-fos in middle-aged females. Brain IGF-I receptor blockade did not modify E2 induction of progestin receptor-immunoreactive neurons in the preoptic area, arcuate, or ventromedial hypothalamus of young rats. These findings indicate that brain IGF-I receptors are required for E2 activation of GnRH neurons in young rats and for robust GnRH release from axon terminals in middle-aged females. IGF-I likely exerts its effects by actions on E2-sensitive neurons that are upstream of GnRH neurons and terminals.
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Affiliation(s)
- Yan Sun
- Department of Obstetrics/Gynecology and Women's Health, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Ullmann 1211, Bronx, New York 10461, USA
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Pan Y, Xu L, Wang Z, Zhang Z. Expression of oestrogen receptor α in the brain of Brandt's voles (Lasiopodomys brandtii ): sex differences and variations during ovarian cycles. J Neuroendocrinol 2011; 23:926-32. [PMID: 21848648 DOI: 10.1111/j.1365-2826.2011.02210.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Oestrogen receptor (ER) α plays an important role in a variety of cognitive and behavioural functions. It has been shown that ERα expression in the brain is sexually dimorphic and is influenced by circulating oestrogen. In the present study, we mapped ERα-immunoreactive (-ir) cells in the forebrain of Brandt's voles (Lasiopodomys brandtii) to examine differences in ERα-ir expression between males and females and to reveal variations of ERα-ir expression during ovarian cycles in females. ERα-ir cells were found in many forebrain regions, including the lateral septum, bed nucleus of the stria terminalis, medial preoptic area (MPOA), anterior, arcuate and ventral medial (VMH) nuclei of the hypothalamus, as well as medial (MeA) and anterior cortical nuclei of the amygdala. Females had more ERα-ir cells in the VMH than males. Females during ovarian oestrus, but not di-oestrus or pro-oestrus, also had more ERα-ir cells in the MPOA than males. Furthermore, females in ovarian di-oestrus or oestrus had more ERα-ir cells in the MeA than males. Together, these data indicate that ERα expression in the brain of Brandt's voles is sexually dimorphic in specific brain areas. In addition, variations in the levels of circulating oestrogen during ovarian cycles can affect ERα expression in the female brain in a region-specific manner.
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Affiliation(s)
- Y Pan
- State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture, Institute of Zoology, Chinese Academy of Sciences, Chaoyang District, Beijing, China
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Deurveilher S, Rusak B, Semba K. Female reproductive hormones alter sleep architecture in ovariectomized rats. Sleep 2011; 34:519-30. [PMID: 21461331 DOI: 10.1093/sleep/34.4.519] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
STUDY OBJECTIVES Treating ovariectomized rats with physiological levels of estradiol and/or progesterone affects aspects of both baseline (24 h) sleep and recovery (18 h) sleep after 6 h of sleep deprivation. We have extended the analysis of these effects by examining several additional parameters of sleep architecture using the same data set as in our previous study (Deurveilher et al. SLEEP 2009;32(7):865-877). DESIGN Sleep in ovariectomized rats implanted with oil, 17 β-estradiol and/or progesterone capsules was recorded using EEG and EMG before, during, and after 6 h of sleep deprivation during the light phase of a 12/12 h light/dark cycle. MEASUREMENTS AND RESULTS During the baseline dark, but not light, phase, treatments with estradiol alone or combined with progesterone decreased the mean duration of non-rapid eye movement sleep (NREMS) episodes and the number of REMS episodes, while also increasing brief awakenings, consistent with the previously reported lower baseline NREMS and REMS amounts. Following sleep deprivation, the hormonal treatments caused a larger percentage increase from baseline in the mean durations of NREMS and REMS episodes, and a larger percentage decrease in brief awakenings, consistent with the previously reported larger increase in recovery REMS amount. There were no hormonal effects on NREMS and REMS EEG power values, other than on recovery NREMS delta power, as previously reported. CONCLUSIONS Physiological levels of estradiol and/or progesterone in female rats modulate sleep architecture differently at baseline and after acute sleep loss, fragmenting baseline sleep while consolidating recovery sleep. These hormones also play a role in the diurnal pattern of NREMS maintenance.
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Affiliation(s)
- Samüel Deurveilher
- Department of Anatomy & Neurobiology, Dalhousie University, Halifax, Nova Scotia, Canada
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31
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Abstract
We examined the induction of progesterone receptor-immunoreactive (PR-ir) cells by estrogen in the rat preoptic area and ventromedial hypothalamic nucleus. Ovariectomized young (3-month-old) and old (24-month-old) female rats were treated with estrogen or cholesterol for 4 days. Estrogen significantly increased PR-ir cells in the preoptic area and ventromedial hypothalamic nucleus in young rats. Cholesterol-treated old rats had very few PR-ir cells; estrogen treatment significantly increased the number of PR-ir cells in both the preoptic area and the ventromedial hypothalamic nucleus in old rats, although less than in young rats. Therefore, the ability of estrogen to induce PR immunoreactivity in the hypothalamus in ovariectomized rats is attenuated in old rats compared with young rats.
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Spary EJ, Maqbool A, Batten TFC. Changes in oestrogen receptor alpha expression in the nucleus of the solitary tract of the rat over the oestrous cycle and following ovariectomy. J Neuroendocrinol 2010; 22:492-502. [PMID: 20236229 DOI: 10.1111/j.1365-2826.2010.01977.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Oestrogen is capable of modulating autonomic outflow and baroreflex function via actions on groups of neurones in the brainstem. We investigated the presence of oestrogen receptor (ER) alpha in a part of the nucleus of the solitary tract (NTS) associated with central cardiovascular control, aiming to determine whether ERalpha mRNA and protein expression is correlated with levels of circulating oestrogen during the oestrous cycle. Polymerase chain reaction (PCR) detected ERalpha mRNA in the NTS at each stage of the oestrous cycle, from ovariectomised, sham-operated and male rats. Real-time PCR showed variations in ERalpha mRNA expression during the oestrous cycle, with the highest levels seen in oestrus, and lowest levels in metoestrus (P < 0.05 versus oestrus) and proestrus (P < 0.05 versus oestrus). Expression in males was lower than in dioestrus and oestrus females (P < 0.05). After ovariectomy, ERalpha mRNA levels were decreased compared to sham-operated animals (P < 0.01). Confocal fluorescence immunohistochemistry with stereological analysis showed that numbers of ERalpha immunoreactive cell nuclei per mm(3) of tissue in the caudal NTS were significantly greater in proestrus than in other groups of rats (P < 0.05). There were also differences among the groups in the extent of colocalisation of ERalpha in neurones immunoreactive for tyrosine hydroxylase and nitric oxide synthase. These results imply a complex pattern of region-specific oestrogen signalling in the NTS and suggest that ERalpha expression in this important autonomic nucleus may be related to circulating oestrogen levels. This may have consequences for the regulation of autonomic tone and baroreflex sensitivity when oestrogen levels decline, for example following menopause.
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Affiliation(s)
- E J Spary
- Division of Cardiovascular and Neuronal Remodelling, LIGHT Institute, University of Leeds, Leeds, UK.
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Ducret E, Gaidamaka G, Herbison AE. Electrical and morphological characteristics of anteroventral periventricular nucleus kisspeptin and other neurons in the female mouse. Endocrinology 2010; 151:2223-32. [PMID: 20211970 DOI: 10.1210/en.2009-1480] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Neurons in the rodent anteroventral periventricular nucleus (AVPV) play a key role in integrating circadian and gonadal steroid hormone information in the control of fertility. In particular, estradiol-sensitive kisspeptin neurons located in the AVPV, and adjacent structures [together termed the rostral periventricular area of the third ventricle (RP3V)], are critical for puberty onset and the preovulatory LH surge. The present study aimed to establish the morphological and electrical firing characteristics of RP3V neurons, including kisspeptin neurons, in the adult female mouse. Cell-attached electrical recordings, followed by juxtacellular dye filling, of 129 RP3V neurons in the acute brain slice preparation revealed these cells to exhibit multipolar (53%), bipolar (43%), or unipolar (4%) dendritic morphologies along with silent (16%), irregular (41%), bursting (25%), or tonic (34%) firing patterns. Postrecording immunocytochemistry identified 17 of 100 filled RP3V cells as being kisspeptin neurons, all of which exhibited complex multipolar dendritic trees and significantly (P < 0.05) higher bursting or high tonic firing rates compared with nonkisspeptin neurons. The firing pattern of RP3V neurons fluctuated across the estrous cycle with a significant (P < 0.05) switch from irregular to tonic firing patterns found on proestrus. A similar nonsignificant trend was found for kisspeptin neurons. All RP3V neurons responded to gamma-aminobutyric acid and glutamate, about 10% to RFamide-related peptide-3, about 5% to vasopressin, 0% to vasoactive intestinal peptide, and 0% to kisspeptin. These studies provide a morphological and electrical description of AVPV/RP3V neurons and demonstrate their cycle-dependent firing patterns along with an unexpected lack of acute response to the circadian neuropeptides.
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Affiliation(s)
- Eric Ducret
- Centre for Neuroendocrinology, Department of Physiology, University of Otago School of Medical Sciences, New Zealand
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Monje L, Varayoud J, Muñoz-de-Toro M, Luque E, Ramos J. Neonatal exposure to bisphenol A alters estrogen-dependent mechanisms governing sexual behavior in the adult female rat. Reprod Toxicol 2009; 28:435-42. [DOI: 10.1016/j.reprotox.2009.06.012] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2009] [Revised: 06/16/2009] [Accepted: 06/25/2009] [Indexed: 11/15/2022]
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Spary EJ, Maqbool A, Batten TFC. Oestrogen receptors in the central nervous system and evidence for their role in the control of cardiovascular function. J Chem Neuroanat 2009; 38:185-96. [PMID: 19505570 DOI: 10.1016/j.jchemneu.2009.05.008] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2009] [Revised: 05/05/2009] [Accepted: 05/27/2009] [Indexed: 02/07/2023]
Abstract
Oestrogen is considered beneficial to cardiovascular health through protective effects not only on the heart and vasculature, but also on the autonomic nervous system via actions on oestrogen receptors. A plethora of evidence supports a role for the hormone within the central nervous system in modulating the pathways regulating cardiovascular function. A complex interaction of several brainstem, spinal and forebrain nuclei is required to receive, integrate and co-ordinate inputs that contribute appropriate autonomic reflex responses to changes in blood pressure and other cardiovascular parameters. Central effects of oestrogen and oestrogen receptors have already been demonstrated in many of these areas. In addition to the classical nuclear oestrogen receptors (ERalpha and ERbeta) a recently discovered G-protein coupled receptor, GPR30, has been shown to be a novel mediator of oestrogenic action. Many anatomical and molecular studies have described a considerable overlap in the regional expression of these receptors; however, the receptors do exhibit specific characteristics and subtype specific expression is found in many autonomic brain areas, for example ERbeta appears to predominate in the hypothalamic paraventricular nucleus, whilst ERalpha is important in the nucleus of the solitary tract. This review provides an overview of the available information on the localisation of oestrogen receptor subtypes and their multitude of possible modulatory actions in different groups of neurochemically and functionally defined neurones in autonomic-related areas of the brain.
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Affiliation(s)
- Emma J Spary
- Division of Cardiovascular and Neuronal Remodelling, Worsley Building, LIGHT Institute, University of Leeds, Leeds LS2 9JT, UK.
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36
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Sex steroidal hormones and respiratory control. Respir Physiol Neurobiol 2009; 164:213-21. [PMID: 18599386 DOI: 10.1016/j.resp.2008.06.006] [Citation(s) in RCA: 124] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2008] [Revised: 06/06/2008] [Accepted: 06/07/2008] [Indexed: 12/26/2022]
Abstract
There is a growing public awareness that sex hormones can have an impact on a variety of physiological processes. Yet, despite almost a century of research, we still do not have a clear picture as to the effects of sex hormones on the regulation of breathing. Considerable data has accumulated showing that estrogen, progesterone and testosterone can influence respiratory function in animals and humans. Several disorders of breathing such as obstructive sleep apnea (OSA) and sudden infant death syndrome (SIDS) show clear sex differences in their prevalence, lending weight to the importance of sex hormones in respiratory control. This review focuses on questions such as: how early do sex hormones influence breathing? Which is the most effective? Where do sex hormones exert their effects? What mechanisms are involved? Are there age-associated changes? A clearer understanding of how sex hormones influence the control of breathing could enable sex- and age-specific therapeutic interventions for diseases of the respiratory control system.
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Veiga-Lopez A, Astapova OI, Aizenberg EF, Lee JS, Padmanabhan V. Developmental programming: contribution of prenatal androgen and estrogen to estradiol feedback systems and periovulatory hormonal dynamics in sheep. Biol Reprod 2009; 80:718-725. [PMID: 19122183 PMCID: PMC2804826 DOI: 10.1095/biolreprod.108.074781] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2008] [Revised: 12/05/2008] [Accepted: 12/29/2008] [Indexed: 11/04/2023] Open
Abstract
Prenatal testosterone excess leads to neuroendocrine and periovulatory disruptions in the offspring culminating in progressive loss of cyclicity. It is unknown whether the mediary of these disruptions is androgen or estrogen, because testosterone can be aromatized to estrogen. Taking a reproductive life span approach of studying control, prenatal testosterone, and dihydrotestosterone-treated offspring, this study tested the hypothesis that disruptions in estradiol-negative but not -positive feedback effects are programmed by androgenic actions of testosterone and that these disruptions in turn will have an impact on the periovulatory hormonal dynamics. The approach was to test estradiol-negative and -positive feedback responses of all three groups of ovary-intact females during prepubertal age and then compare the periovulatory dynamics of luteinizing hormone, follicle-stimulating hormone, estradiol, and progesterone during the first breeding season. The findings show that estradiol-negative but not estradiol-positive feedback disruptions in prenatal testosterone-treated females are programmed by androgenic actions of prenatal testosterone excess and that follicular phase estradiol and gonadotropins surge disruptions during reproductive life are consistent with estrogenic programming. Additional studies carried out testing estradiol-positive feedback response over time found progressive deterioration of estradiol-positive feedback in prenatal testosterone-treated sheep until the time of puberty. Together, these findings provide insight into the mechanisms by which prenatal testosterone disrupts the reproductive axis. The findings may be of translational relevance since daughters of mothers with hyperandrogenism are at risk of increased exposure to androgens.
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Affiliation(s)
- Almudena Veiga-Lopez
- Department of Pediatrics and the Reproductive Sciences Program, University of Michigan, Ann Arbor, Michigan
| | - Olga I. Astapova
- Department of Pediatrics and the Reproductive Sciences Program, University of Michigan, Ann Arbor, Michigan
| | - Esther F. Aizenberg
- Department of Pediatrics and the Reproductive Sciences Program, University of Michigan, Ann Arbor, Michigan
| | - James S. Lee
- Department of Pediatrics and the Reproductive Sciences Program, University of Michigan, Ann Arbor, Michigan
| | - Vasantha Padmanabhan
- Department of Pediatrics and the Reproductive Sciences Program, University of Michigan, Ann Arbor, Michigan
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Abstract
Ovulation is central to mammalian fertility, yet the precise mechanism through which oestrogen triggers the gonadotrophin-releasing hormone (GnRH) surge that generates the pre-ovulatory luteinising hormone (LH) surge has remained elusive. The recent discovery that kisspeptin-GPR54 signalling is an essential regulator of the neuroendocrine axis at puberty has led investigators to evaluate the role of kisspeptin in the pre-ovulatory GnRH surge mechanism. Kisspeptin neurones are known to express oestrogen and progesterone receptors and have their cell bodies located in brain regions implicated in the positive-feedback mechanism in several mammalian species. In rodents, kisspeptin neurones located in the rostral periventricular area of the third ventricle (RP3V) are positively regulated by oestrogen and most likely are activated by oestrogen at the time of positive feedback. A similar scenario appears to exist for a sub-population of kisspeptin neurones located in the mediobasal hypothalamus of sheep and primates. The majority of GnRH neurones express GPR54, and kisspeptin causes an intense electrical activation of these cells. In concordance with this, kisspeptin administration in vivo results in an abrupt and prolonged release of LH in all mammalian species examined to date. Functional evidence from immunoneutralisation and knockout studies suggests that RP3V kisspeptin neurones projecting to GnRH neurones are an essential component of the surge mechanism in rodents. Taken together, the studies undertaken to date provide substantial evidence in support of a key role of kisspeptin-GPR54 signalling in the generation of the oestrogen-induced pre-ovulatory surge mechanism in mammals.
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Affiliation(s)
- J Clarkson
- Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
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Christian CA, Pielecka-Fortuna J, Moenter SM. Estradiol suppresses glutamatergic transmission to gonadotropin-releasing hormone neurons in a model of negative feedback in mice. Biol Reprod 2009; 80:1128-35. [PMID: 19176881 DOI: 10.1095/biolreprod.108.075077] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
A surge of gonadotropin-releasing hormone (GnRH) release from the brain triggers the luteinizing hormone (LH) surge that causes ovulation. The GnRH surge is initiated by a switch in estradiol action from negative to positive feedback. Estradiol signals critical for the surge are likely transmitted to GnRH neurons at least in part via estradiol-sensitive afferents. Using an ovariectomized estradiol-treated (OVX+E) mouse model that exhibits daily LH surges, we examined changes in glutamate transmission to GnRH neurons during negative feedback and positive feedback. Spontaneous glutamatergic excitatory postsynaptic currents (EPSCs) mediated by alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid/kainate receptors (AMPA/KA Rs) or N-methyl-D-aspartate receptors (NMDARs) were recorded in GnRH neurons from OVX+E and OVX mice. There were no diurnal changes in the percentage of GnRH neurons from OVX mice exhibiting EPSCs. In cells from OVX+E mice, the profile of AMPA/KA R-mediated and NMDAR-mediated EPSCs showed changes dependent on time of day. Comparison of AMPA/KA R-mediated EPSC frequency in OVX+E and OVX cells showed that estradiol suppressed transmission during negative feedback but had no effect during positive feedback. Tetrodotoxin treatment to block action potential firing did not affect AMPA/KA R-mediated EPSC frequency in OVX cells during negative feedback or in OVX+E cells during positive feedback, suggesting that estradiol-induced suppression of glutamate transmission may be primarily due to activity-independent changes. The diurnal removal of estradiol-induced suppression of AMPA/KA R-mediated glutamate transmission to GnRH neurons during positive feedback suggests that the primary role for estradiol-induced changes in glutamate transmission may be in mediating negative feedback.
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Affiliation(s)
- Catherine A Christian
- Neuroscience Graduate Program, Departments of Medicine and Cell Biology, University of Virginia, Charlottesville, Virginia 22908, USA
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40
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Scharfman HE, MacLusky NJ. Estrogen-growth factor interactions and their contributions to neurological disorders. Headache 2008; 48 Suppl 2:S77-89. [PMID: 18700946 DOI: 10.1111/j.1526-4610.2008.01200.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Estrogen has diverse and powerful effects in the brain, including actions on neurons, glia, and the vasculature. It is not surprising, therefore, that there are many changes in the female brain as serum estradiol levels rise and fall during the normal ovarian cycle. At times of life when estradiol levels change dramatically, such as puberty, postpartum, or menopause, there also are dramatic changes in the central nervous system. Changes that occur because of fluctuations in serum estrogen levels are potentially relevant to neurological disorders because symptoms often vary with the time of the ovarian cycle. Moreover, neurological disorders (eg, seizures and migraine) often increase in frequency in women when estradiol levels change. In this review, the contribution of 2 growth factors targeted by estrogen, the neurotrophin brain-derived neurotrophic factor (BDNF) and vascular endothelial growth factor (VEGF), will be discussed. Estrogen-sensitive response elements are present on the genes for both BDNF and VEGF, and they are potent modulators of neuronal, glial, and vascular function, making them logical candidates to mediate the multitude of effects of estrogen. In addition, BDNF induces neuropeptide Y, which has diverse actions that are relevant to estrogen action and to the same neurological disorders.
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Affiliation(s)
- Helen E Scharfman
- Nathan Kline Institute for Psychiatric Research & New York University School of Medicine, Orangeburg, NY 10962, USA
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Vida B, Hrabovszky E, Kalamatianos T, Coen CW, Liposits Z, Kalló I. Oestrogen receptor alpha and beta immunoreactive cells in the suprachiasmatic nucleus of mice: distribution, sex differences and regulation by gonadal hormones. J Neuroendocrinol 2008; 20:1270-7. [PMID: 18752649 DOI: 10.1111/j.1365-2826.2008.01787.x] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Oestrogen regulates various aspects of circadian rhythm physiology. The presence of oestrogen receptors within the suprachiasmatic nucleus (SCN), the principal circadian oscillator, indicates that some actions of oestrogen on circadian functions may be exerted at that site. The present study analysed sex differences, topographic distribution, and neurochemical phenotype of neurones expressing the alpha and beta subtypes of oestrogen receptors (ERalpha and ERbeta) in the mouse SCN. We found that relatively few neurones in the SCN are immunoreactive (IR) for ERalpha (approximately 4.5% in females and 3% in males), but five- to six-fold more SCN neurones express ERbeta. ER-IR neurones are primarily in the shell subdivision of the nucleus and show differences between the sexes, significantly greater numbers being found in females. Treatment of male or female gonadectomised mice with oestradiol benzoate for 24 h substantially reduced the number of ERbeta-IR neurones, but not ERalpha-IR neurones. Double-labelling immunocytochemical experiments to characterise the phenotype of the oestrogen-receptive neurones showed the presence of the calcium-binding proteins calretinin or calbindin D28K in approximately 12% and 10%, respectively, of ERalpha-IR neurones. A higher proportion (approximately 38%) of ERbeta-IR neurones contains calbindin D28K; a few (approximately 2%) express calretinin or vasopressin. These double-labelled cells appear primarily in the shell subdivision of the SCN. Neither vasoactive intestinal polypeptide- nor gastrin releasing peptide-immunoreactivity was observed in ER-IR neurones. These data indicate that the primary target cells for oestrogen are in the shell subdivision of the nucleus. The sexually differentiated expression and distribution of ERalpha and ERbeta in various cell populations of the SCN suggest multiple modes of oestrogen signalling within this nucleus, which may modulate circadian functions.
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Affiliation(s)
- B Vida
- Department of Endocrine Neurobiology, Institute of Experimental Medicine, Budapest, Hungary
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Christian CA, Glidewell-Kenney C, Jameson JL, Moenter SM. Classical estrogen receptor alpha signaling mediates negative and positive feedback on gonadotropin-releasing hormone neuron firing. Endocrinology 2008; 149:5328-34. [PMID: 18635656 PMCID: PMC2584581 DOI: 10.1210/en.2008-0520] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2008] [Accepted: 07/09/2008] [Indexed: 01/22/2023]
Abstract
During the female reproductive cycle, the neuroendocrine action of estradiol switches from negative feedback to positive feedback to initiate the preovulatory GnRH and subsequent LH surges. Estrogen receptor-alpha (ERalpha) is required for both estradiol negative and positive feedback regulation of LH. ERalpha may signal through estrogen response elements (EREs) in DNA and/or via ERE-independent pathways. Previously, a knock-in mutant allele (ERalpha-/AA) that selectively restores ERE-independent signaling onto the ERalpha-/- background was shown to confer partial negative but not positive estradiol feedback on serum LH. The current study investigated the roles of the ERE-dependent and ERE-independent ERalpha pathways for estradiol feedback at the level of GnRH neuron firing activity. The above ERalpha genetic models were crossed with GnRH-green fluorescent protein mice to enable identification of GnRH neurons in brain slices. Targeted extracellular recordings were used to monitor GnRH neuron firing activity using an ovariectomized, estradiol-treated mouse model that exhibits diurnal switches between negative and positive feedback. In wild-type mice, GnRH neuron firing decreased in response to estradiol during negative feedback and increased during positive feedback. In contrast, both positive and negative responses to estradiol were absent in GnRH neurons from ERalpha-/- and ERalpha-/AA mice. ERE-dependent signaling is thus required to increase GnRH neuron firing to generate a GnRH/LH surge. Furthermore, ERE-dependent and -independent ERalpha signaling pathways both appear necessary to mediate estradiol negative feedback on serum LH levels, suggesting central and pituitary estradiol feedback may use different combinations of ERalpha signaling pathways.
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Affiliation(s)
- Catherine A Christian
- Neuroscience Graduate Program, Department of Medicine, University of Virginia, Charlottesville, Virginia 22908, USA
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Christian CA, Moenter SM. Critical roles for fast synaptic transmission in mediating estradiol negative and positive feedback in the neural control of ovulation. Endocrinology 2008; 149:5500-8. [PMID: 18617615 PMCID: PMC2584596 DOI: 10.1210/en.2008-0453] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
A switch in the balance of estradiol feedback actions from negative to positive initiates the GnRH surge, triggering the LH surge that causes ovulation. Using an ovariectomized, estradiol-treated (OVX+E) mouse model that exhibits daily switches between negative in the morning and positive feedback in the evening, we investigated the roles of fast synaptic transmission in regulating GnRH neuron firing during negative and positive feedback. Targeted extracellular recordings were used to monitor activity of GnRH neurons from OVX+E and OVX mice in control solution or solution with antagonists to both ionotropic glutamate and gamma-aminobutyric acid receptors (blockade). Blockade had no effect on activity of OVX cells. In contrast, in OVX+E cells in the morning, blockade increased activity compared with control cells, whereas in the evening, blockade decreased activity. In vivo barbiturate sedation of OVX+E mice that blocked LH surge induction prevented the in vitro evening changes in firing rate and response to blockade. These observations suggest at least partial inversion of the negative-to-positive switch in estradiol feedback action and indicate that changes in fast synaptic transmission to GnRH neurons and within the network of cells presynaptic to GnRH neurons are critical for mediating estradiol negative and positive feedback actions on GnRH neurons. Fast synaptic transmission may also affect GnRH neuron activity indirectly through altering release of excitatory and inhibitory neuromodulators onto GnRH neurons at specific times of day. Fast synaptic transmission is thus critical for proper generation and timing of the GnRH surge.
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Affiliation(s)
- Catherine A Christian
- Neuroscience Graduate Program, Department of Medicine, University of Virginia, Charlottesville, Virginia 22908, USA
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Kisspeptin-GPR54 signaling is essential for preovulatory gonadotropin-releasing hormone neuron activation and the luteinizing hormone surge. J Neurosci 2008; 28:8691-7. [PMID: 18753370 DOI: 10.1523/jneurosci.1775-08.2008] [Citation(s) in RCA: 350] [Impact Index Per Article: 21.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Kisspeptin and its receptor GPR54 have recently been identified as key signaling partners in the neural control of fertility in animal models and humans. The gonadotropin-releasing hormone (GnRH) neurons represent the final output neurons of the neural network controlling fertility and are suspected to be the primary locus of kisspeptin-GPR54 signaling. Using mouse models, the present study addressed whether kisspeptin and GPR54 have a key role in the activation of GnRH neurons to generate the luteinizing hormone (LH) surge responsible for ovulation. Dual-label immunocytochemistry experiments showed that 40-60% of kisspeptin neurons in the rostral periventricular area of the third ventricle (RP3V) expressed estrogen receptor alpha and progesterone receptors. Using an ovariectomized, gonadal steroid-replacement regimen, which reliably generates an LH surge, approximately 30% of RP3V kisspeptin neurons were found to express c-FOS in surging mice compared with 0% in nonsurging controls. A strong correlation was found between the percentage of c-FOS-positive kisspeptin neurons and the percentage of c-FOS-positive GnRH neurons. To evaluate whether kisspeptin and/or GPR54 were essential for GnRH neuron activation and the LH surge, Gpr54- and Kiss1-null mice were examined. Whereas wild-type littermates all exhibited LH surges and c-FOS in approximately 50% of their GnRH neurons, none of the mutant mice from either line showed an LH surge or any GnRH neurons with c-FOS. These observations provide the first evidence that kisspeptin-GPR54 signaling is essential for GnRH neuron activation that initiates ovulation. This broadens considerably the potential roles and therapeutic possibilities for kisspeptin and GPR54 in fertility regulation.
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Hu L, Gustofson RL, Feng H, Leung PK, Mores N, Krsmanovic LZ, Catt KJ. Converse regulatory functions of estrogen receptor-alpha and -beta subtypes expressed in hypothalamic gonadotropin-releasing hormone neurons. Mol Endocrinol 2008; 22:2250-9. [PMID: 18701637 DOI: 10.1210/me.2008-0192] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Estradiol (E(2)) acts as a potent feedback molecule between the ovary and hypothalamic GnRH neurons, and exerts both positive and negative regulatory actions on GnRH synthesis and secretion. However, the extent to which these actions are mediated by estrogen receptors (ERs) expressed in GnRH neurons has been controversial. In this study, Single-cell RT-PCR revealed the expression of both ERalpha and ERbeta isoforms in cultured fetal and adult rat hypothalamic GnRH neurons. Both ERalpha and ERbeta or individual ERs were expressed in 94% of cultured fetal GnRH neurons. In adult female rats at diestrus, 68% of GnRH neurons expressed ERs, followed by 54% in estrus and 19% in proestrus. Expression of individual ERs was found in 24% of adult male GnRH neurons. ERalpha exerted marked G(i)-mediated inhibitory effects on spontaneous action potential (AP) firing, cAMP production, and pulsatile GnRH secretion, indicating its capacity for negative regulation of GnRH neuronal function. In contrast, increased E(2) concentration and ERbeta agonists increase the rate of AP firing, GnRH secretion, and cAMP production, consistent with ERbeta-dependent positive regulation of GnRH secretion. Consonant with the coupling of ERalpha to pertussis toxin-sensitive G(i/o) proteins, E(2) also activates G protein-activated inwardly rectifying potassium channels, decreasing membrane excitability and slowing the firing of spontaneous APs in hypothalamic GnRH neurons. These findings demonstrate that the dual actions of E(2) on GnRH neuronal membrane excitability, cAMP production, and GnRH secretion are mediated by the dose-dependent activation of ERalpha and ERbeta expressed in hypothalamic GnRH neurons.
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Affiliation(s)
- Lian Hu
- Endocrinology and Reproduction Research Branch, PDEGEN, National Institue of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892-4510, USA
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Christian CA, Moenter SM. Vasoactive intestinal polypeptide can excite gonadotropin-releasing hormone neurons in a manner dependent on estradiol and gated by time of day. Endocrinology 2008; 149:3130-6. [PMID: 18326000 PMCID: PMC2408801 DOI: 10.1210/en.2007-1098] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
A surge of GnRH release signals the LH surge that triggers ovulation. The GnRH surge is dependent on a switch in estradiol feedback from negative to positive and, in rodents, a daily neural signal, likely from the suprachiasmatic nuclei. Vasoactive intestinal polypeptide (VIP) may be involved in suprachiasmatic nuclei-GnRH neuron communication. Here we assessed the effects of acute VIP (5 min treatment) on GnRH neuron function using targeted extracellular recordings of firing activity of GnRH neurons in brain slices. We examined the effect of VIP on firing rate at different times of day using an established ovariectomized, estradiol-treated (OVX+E) mouse model that exhibits daily LH surges timed to the late afternoon. Cells from OVX animals (no estradiol) did not respond to VIP, regardless of time of day. With estradiol, the effect of VIP on GnRH neurons was dependent on the time of recording. During negative feedback, OVX+E cells did not respond. VIP increased firing in cells recorded during surge onset, but this excitatory response was reduced at surge peak. Acute treatment of OVX+E cells during surge peak with a VIP receptor antagonist decreased GnRH neuron firing. This suggests endogenous VIP may both increase GnRH neuron firing during the surge and occlude response to exogenous VIP. These data provide functional evidence for VIP effects on GnRH neurons and indicate that both estradiol and time of day gate the GnRH neuron response to this peptide. VIP may provide an excitatory signal from the circadian clock that helps time the GnRH surge.
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Affiliation(s)
- Catherine A Christian
- Neuroscience Graduate Program, Department of Medicine, University of Virginia, Charlottesville, Virginia 22908, USA
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47
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Teske JA, Billington CJ, Kotz CM. Neuropeptidergic mediators of spontaneous physical activity and non-exercise activity thermogenesis. Neuroendocrinology 2008; 87:71-90. [PMID: 17984627 DOI: 10.1159/000110802] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2007] [Accepted: 09/20/2007] [Indexed: 01/29/2023]
Abstract
Lean individuals have high levels of spontaneous physical activity (SPA) and the energy expenditure derived from that activity, termed non-exercise activity thermogenesis or NEAT, appears to protect them from obesity. Conversely, obesity in different human populations is characterized by low levels of SPA and NEAT. Like in humans, elevated SPA in rats appears to protect against obesity: obesity-resistant rats have significantly greater SPA and NEAT than obesity-prone rats. We review the literature on brain mechanisms important in mediating SPA and NEAT. The focus is on neuropeptides, including cholecystokinin, corticotropin-releasing hormone (also known as corticotropin-releasing factor), neuromedin U, neuropeptide Y, leptin, agouti-related protein, orexin-A (also known as hypocretin-1), and ghrelin. We also review information regarding interactions between these neuropeptides and dopamine, a neurotransmitter important in mediating motor function. Finally, we present evidence that elevated signaling of pathways mediating SPA and NEAT may protect against weight gain and obesity.
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Affiliation(s)
- J A Teske
- VA Medical Center, University of Minnesota, Minneapolis, MN 55417, USA
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Kudwa AE, Harada N, Honda SI, Rissman EF. Effects of organisational oestradiol on adult immunoreactive oestrogen receptors (alpha and beta) in the male mouse brain. J Neuroendocrinol 2007; 19:767-72. [PMID: 17850458 PMCID: PMC2667106 DOI: 10.1111/j.1365-2826.2007.01585.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Steroid hormones act on developing neural circuits that regulate the hypothalamic-pituitary-gonadal axis and are involved in hormone-sensitive behaviours. To test the hypothesis that developmental exposure to oestradiol (E(2)) organises the quantity of adult oestrogen receptors (ERalpha and ERbeta), we used male mice with a targeted mutation of the aromatase enzyme gene (ArKO) and their wild-type (WT) littermates. These mice are unable to aromatise testosterone to E(2), but still express both ERalpha and beta. To evaluate adult responsiveness to E(2), gonadectomised males were implanted with Silastic capsules containing E(2), or an empty implant, 5 days prior to sacrifice. Immunoreactivity for ERalpha and ERbeta was quantified in the caudal ventromedial nucleus (VMN) and the medial preoptic area (POA). Regardless of genotype, adult treatment with E(2) reduced ERalpha-immunoreactive (ir) and ERbeta-ir cell numbers in the POA, as well as ERbeta-ir, but not ERalpha-ir, cell numbers in the VMN. Genotype, and thus endogenous exposure to E(2), produced opposite effects on ER expression in the two brain areas. In the VMN, ArKO males had more ERalpha-ir and ERbeta-ir cells than did WT males. In the POA, ArKO males had fewer ERalpha-ir and ERbeta-ir cells than did WT males. Thus, numbers of immunoreactive neurones containing both ERs in the adult ArKO male were enhanced in the POA, but decreased in the VMN, and most likely these patterns were established during the developmental critical period. Furthermore, although both ERalpha and beta-ir cell numbers are altered by the disruption of the aromatase gene, ERbeta is altered in a more robust and region-specific manner.
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Affiliation(s)
- A E Kudwa
- Neuroscience Graduate Program, University of Virginia, Charlottesville, VA 22908, USA
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Christian CA, Moenter SM. Estradiol induces diurnal shifts in GABA transmission to gonadotropin-releasing hormone neurons to provide a neural signal for ovulation. J Neurosci 2007; 27:1913-21. [PMID: 17314287 PMCID: PMC6673555 DOI: 10.1523/jneurosci.4738-06.2007] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Ovulation is initiated by a surge of gonadotropin-releasing hormone (GnRH) secretion by the brain. GnRH is normally under negative feedback control by ovarian steroids. During sustained exposure to estradiol in the late follicular phase of the reproductive cycle, however, the feedback action of this steroid switches to positive, inducing the surge. Here, we used an established ovariectomized, estradiol-treated (OVX+E) mouse model exhibiting daily surges to investigate the neurobiological mechanisms underlying this switch. Specifically, we examined changes in GABA transmission to GnRH neurons, which can be excited by GABA(A) receptor activation. Spontaneous GABAergic postsynaptic currents (PSCs) were recorded in GnRH neurons from OVX+E and OVX mice in coronal and sagittal slices. There were no diurnal changes in PSC frequency in cells from OVX mice in either slice orientation. In OVX+E cells in both orientations, PSC frequency was low during negative feedback but increased at surge onset. During the surge peak, this increase subsided in coronal slices but persisted in sagittal slices. Comparison of PSCs before and during tetrodotoxin (TTX) treatment showed TTX decreased PSC frequency in OVX+E cells in sagittal slices, but not coronal slices. This indicates estradiol acts on multiple GABAergic afferent populations to increase transmission through both activity-dependent and -independent mechanisms. Estradiol also increased PSC amplitude during the surge. Estradiol and the diurnal cycle thus interact to induce shifts in both GABA transmission and postsynaptic response that would produce appropriate changes in GnRH neuron firing activity and hormone release.
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Affiliation(s)
- Catherine A. Christian
- Neuroscience Graduate Program, Departments of Medicine and Cell Biology, University of Virginia, Charlottesville, Virginia 22908
| | - Suzanne M. Moenter
- Neuroscience Graduate Program, Departments of Medicine and Cell Biology, University of Virginia, Charlottesville, Virginia 22908
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Valera AG, Cavalcante JC, Elias CF, Felício LF. Cocaine- and amphetamine-regulated transcript is overexpressed in the anteroventral periventricular nucleus of pregnant rats. J Neuroendocrinol 2006; 18:711-4. [PMID: 16879170 DOI: 10.1111/j.1365-2826.2006.01457.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The anteroventral periventricular nucleus (AVPV) is sexually dimorphic, presenting a higher neuronal density in females. The AVPV contains a dense collection of oestrogen and progesterone receptors and has been related to the modulation of gonadotrophin-releasing hormone (GnRH) secretion and gene expression in response to circulating hormonal levels. It has been suggested that cocaine- and amphetamine-regulated transcript (CART) is also related to reproductive control because CART immunoreactive fibres are in close apposition with GnRH neurones. A portion of these fibres originate in the AVPV but its role in mediating hormonal action needs to be better explored. We hypothesised that CART expression in the AVPV would be influenced by the reproductive state and, consequently, by hormonal levels. To test this hypothesis, we analysed CART expression in the AVPV of female rats in different reproductive states (pro-oestrous, pregnancy and lactation). We found that, on the 19th day of pregnancy, female rats presented increased CART expression. Our findings indicate that AVPV CART expression is influenced by the reproductive state and that CART neurones in the AVPV may play a role in the hormonal mechanisms involved in the induction of maternal behaviour.
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Affiliation(s)
- A G Valera
- Department of Pathology, School of Veterinary Medicine, University of Sao Paulo, Sao Paulo, Brazil
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