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Jameson AN, Siemann JK, Melchior J, Calipari ES, McMahon DG, Grueter BA. Photoperiod Impacts Nucleus Accumbens Dopamine Dynamics. eNeuro 2023; 10:ENEURO.0361-22.2023. [PMID: 36781229 PMCID: PMC9937087 DOI: 10.1523/eneuro.0361-22.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 12/29/2022] [Accepted: 01/06/2023] [Indexed: 02/15/2023] Open
Abstract
Circadian photoperiod, or day length, changes with the seasons and influences behavior to allow animals to adapt to their environment. Photoperiod is also associated with seasonal rhythms of affective state, as evidenced by seasonality of several neuropsychiatric disorders. Interestingly, seasonality tends to be more prevalent in women for affective disorders such as major depressive disorder and bipolar disorder (BD). However, the underlying neurobiological processes contributing to sex-linked seasonality of affective behaviors are largely unknown. Mesolimbic dopamine input to the nucleus accumbens (NAc) contributes to the regulation of affective state and behaviors. Additionally, sex differences in the mesolimbic dopamine pathway are well established. Therefore, we hypothesize that photoperiod may drive differential modulation of NAc dopamine in males and females. Here, we used fast-scan cyclic voltammetry (FSCV) to explore whether photoperiod can modulate subsecond dopamine signaling dynamics in the NAc core of male and female mice raised in seasonally relevant photoperiods. We found that photoperiod modulates dopamine signaling in the NAc core, and that this effect is sex-specific to females. Both release and uptake of dopamine were enhanced in the NAc core of female mice raised in long, summer-like photoperiods, whereas we did not find photoperiodic effects on NAc core dopamine in males. These findings uncover a potential neural circuit basis for sex-linked seasonality in affective behaviors.
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Affiliation(s)
- Alexis N Jameson
- Neuroscience Graduate Program, Vanderbilt University, Nashville, TN 37232
| | - Justin K Siemann
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37232
| | - James Melchior
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232
| | - Erin S Calipari
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37232
- Vanderbilt Center for Addiction Research, Vanderbilt University, Nashville, TN 37232
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232
| | - Douglas G McMahon
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37232
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232
- Department of Biology, Vanderbilt University, Nashville, TN 37232
| | - Brad A Grueter
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37232
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232
- Vanderbilt Center for Addiction Research, Vanderbilt University, Nashville, TN 37232
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232
- Department of Anesthesiology, Vanderbilt University Medical Center, Nashville, TN 37232
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2
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Transcriptome Analysis of Neuroendocrine Regulation of Ovine Hypothalamus-Pituitary-Ovary Axis during Ovine Anestrus and the Breeding Season. Genes (Basel) 2021; 12:genes12121861. [PMID: 34946810 PMCID: PMC8701943 DOI: 10.3390/genes12121861] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 11/18/2021] [Accepted: 11/22/2021] [Indexed: 12/23/2022] Open
Abstract
Most sheep are seasonal estrus, and they breed in autumn when the days get shorter. Seasonal estrus is an important factor that affects the productivity and fertility of sheep. The key point to solve this problem is to explore the regulation mechanism of estrus in sheep. Therefore, in this study, transcriptomic sequencing technology was used to identify differentially expressed mRNAs in the hypothalamus, pituitary and ovary of Small Tail Han sheep (year-round estrus) and tan sheep (seasonal estrus) among luteal, proestrus and estrus stages. There were 256,923,304,156 mRNAs being identified in the hypothalamus, pituitary and ovary, respectively. Functional analysis showed that the photosensor, leucine and isoleucine biosynthesis pathways were enriched significantly. It is speculated that photoperiod may initiate estrus by stimulating the corresponding pathways in hypothalamus. ODC1, PRLH, CRYBB2, SMAD5, OPN1SW, TPH1 are believed to be key genes involved in the estrogen process. In conclusion, this study expanded the database of indigenous sheep breeds, and also provided new candidate genes for future genetic and molecular studies on the seasonal estrus trait in sheep.
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Coen CW, Bennett NC, Holmes MM, Faulkes CG. Neuropeptidergic and Neuroendocrine Systems Underlying Eusociality and the Concomitant Social Regulation of Reproduction in Naked Mole-Rats: A Comparative Approach. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1319:59-103. [PMID: 34424513 DOI: 10.1007/978-3-030-65943-1_3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The African mole-rat family (Bathyergidae) includes the first mammalian species identified as eusocial: naked mole-rats. Comparative studies of eusocial and solitary mole-rat species have identified differences in neuropeptidergic systems that may underlie the phenomenon of eusociality. These differences are found in the oxytocin, vasopressin and corticotrophin-releasing factor (CRF) systems within the nucleus accumbens, amygdala, bed nucleus of the stria terminalis and lateral septal nucleus. As a corollary of their eusociality, most naked mole-rats remain pre-pubertal throughout life because of the presence of the colony's only reproductive female, the queen. To elucidate the neuroendocrine mechanisms that mediate this social regulation of reproduction, research on the hypothalamo-pituitary-gonadal axis in naked mole-rats has identified differences between the many individuals that are reproductively suppressed and the few that are reproductively mature: the queen and her male consorts. These differences involve gonadal steroids, gonadotrophin-releasing hormone-1 (GnRH-1), kisspeptin, gonadotrophin-inhibitory hormone/RFamide-related peptide-3 (GnIH/RFRP-3) and prolactin. The comparative findings in eusocial and solitary mole-rat species are assessed with reference to a broad range of studies on other mammals.
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Affiliation(s)
- Clive W Coen
- Reproductive Neurobiology, Division of Women's Health, Faculty of Life Sciences & Medicine, King's College London, London, UK.
| | - Nigel C Bennett
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
| | - Melissa M Holmes
- Department of Psychology, University of Toronto Mississauga, Mississauga, ON, Canada.,Department of Ecology & Evolutionary Biology, University of Toronto, Toronto, Canada.,Department of Cell & Systems Biology, University of Toronto, Toronto, Canada
| | - Christopher G Faulkes
- School of Biological and Chemical Sciences, Queen Mary University of London, London, UK
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Szpręgiel I, Wronska D. The role of photoperiod and melatonin in the control of seasonal reproduction in mammals. ROCZNIKI NAUKOWE POLSKIEGO TOWARZYSTWA ZOOTECHNICZNEGO 2020. [DOI: 10.5604/01.3001.0014.6071] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
<b>Melatonin secreted by pineal cells is a hormone whose biosynthesis is coordinated by neurons of the master clock located in the hypothalamic suprachiasmatic nuclei (SCN), characterized by the generation of a 24-hour rhythm. In many species of mammals, fluctuations in melatonin secretion affect reproductive functions, e.g. by regulating the frequency and amount of pulsatile secretion of hypothalamic and gonadotropic hormones. Seasonal breeding is a common adaptive strategy among mammals, allowing them to reproduce during the periods of the year that are most favourable for the later survival and growth of the offspring. This type of reproduction is characteristic of sheep, with winter reproductive activity, and hamsters, with summer reproductive activity. In these animals, melatonin synthesis is largely regulated by the photoperiod, which indirectly influences the period of reproductive activity or passivity. The aim of this study was to gather available knowledge on melatonin as a key element controlling seasonal reproduction. The paper presents the general shape of the circadian rhythm and the neuroendocrine mechanism regulating animal reproduction depending on the variable photoperiod. The collected results suggest that melatonin, kisspeptins, gonadotropin-releasing hormone (GnRH), sex hormones and thyroid hormones participate in the regulation of seasonal reproduction in mammals. </b>
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Affiliation(s)
- Izabela Szpręgiel
- University of Agriculture in Krakow Faculty of Animal Sciences Department of Animal Physiology and Endocrinology
| | - Danuta Wronska
- University of Agriculture in Krakow Faculty of Animal Sciences Department of Animal Physiology and Endocrinology
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5
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Yang H, Lin S, Lei X, Yuan C, Yu Y, Zhao Z, Chen J. Nutritional status affects the microRNA profile of the hypothalamus of female sheep. Reprod Fertil Dev 2019; 30:946-957. [PMID: 29366447 DOI: 10.1071/rd17179] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Accepted: 10/21/2017] [Indexed: 12/19/2022] Open
Abstract
Recent studies on the seasonal regulation of the oestrous cycle in sheep have focussed mainly on the responses to photoperiod. However, the brain systems that control reproductive activity also respond to nutritional inputs, although the molecular mechanisms involved are not completely understood. One possibility is that small, non-coding RNAs, such as micro-RNAs (miRNAs), have significant influence. In the present study, the amounts and characteristics of miRNAs in hypothalamus from oestrous and anestrous ewes, fed low- or high-nutrient diets, were compared using Illumina HiSeq sequencing technology. In total, 398 miRNAs, including 261 novel miRNAs, were identified in ewes with an enhanced nutritional status (HEN), whereas 384 miRNAs, including 247 novel miRNAs, were identified in the ewes with a lesser nutritional status (HAN). There were eight conserved and 140 novel miRNAs expressed differentially between the two libraries. Based on quantitative real-time polymerase chain reaction, six miRNAs were assessed to verify the accuracy of the library database. Moreover, the correlation between the miRNA target and several upstream and downstream genes in the oestrus-related pathways were also verified in hypothalamus nerve cells. According to the results, nutritional status plays an important role in oestrous regulation in sheep, and the hypothalamic processes and pathways induced by nutritional signals (folic acid and tyrosine) are different from those induced by photoperiodic regulation of oestrus. We have expanded the repertoire of sheep miRNAs that could contribute to the molecular mechanisms that regulate the initiation of oestrous cycles in anestrous ewes in response to the influence of nutritional status.
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Affiliation(s)
- Heng Yang
- College of Animal Science and Technology, Shihezi University, North Fourth Road, Shihezi 832003, China
| | - Shan Lin
- College of Life Sciences, Shihezi University, North Fourth Road, Shihezi 832003, China
| | - Xiaoping Lei
- College of Animal Science and Technology, Shihezi University, North Fourth Road, Shihezi 832003, China
| | - Cong Yuan
- College of Animal Science and Technology, Shihezi University, North Fourth Road, Shihezi 832003, China
| | - Yaosheng Yu
- College of Animal Science and Technology, Shihezi University, North Fourth Road, Shihezi 832003, China
| | - Zongsheng Zhao
- College of Animal Science and Technology, Shihezi University, North Fourth Road, Shihezi 832003, China
| | - Jingbo Chen
- College of Animal Science and Technology, Shihezi University, North Fourth Road, Shihezi 832003, China
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Medger K, Bennett NC, Chimimba CT, Oosthuizen MK, Mikkelsen JD, Coen CW. Analysis of gonadotrophin-releasing hormone-1 and kisspeptin neuronal systems in the nonphotoregulated seasonally breeding eastern rock elephant-shrew (Elephantulus myurus). J Comp Neurol 2018; 526:2388-2405. [PMID: 30004584 DOI: 10.1002/cne.24498] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Revised: 06/08/2018] [Accepted: 06/19/2018] [Indexed: 12/18/2022]
Abstract
Of the 18 sub-Saharan elephant-shrew species, only eastern rock elephant-shrews reproduce seasonally throughout their distribution, a process seemingly independent of photoperiod. The present study characterizes gonadal status and location/intensity of gonadotrophin-releasing hormone-1 (GnRH-1) and kisspeptin immunoreactivities in this polyovulating species in the breeding and nonbreeding seasons. GnRH-1-immunoreactive (ir) cell bodies are predominantly in the medial septum, diagonal band, and medial preoptic area; processes are generally sparse except in the external median eminence. Kisspeptin-ir cell bodies are detected only within the arcuate nucleus; the density of processes is generally low, except in the septohypothalamic nucleus, ventromedial bed nucleus of the stria terminalis, arcuate nucleus, and internal and external median eminence. Kisspeptin-ir processes are negligible at locations containing GnRH-1-ir cell bodies. The external median eminence is the only site with conspicuously overlapping distributions of the respective immunoreactivities and, accordingly, a putative site for kisspeptin's regulation of GnRH-1 release in this species. In the nonbreeding season in males, there is an increase in the rostral population of GnRH-1-ir cell bodies and density of GnRH-1-ir processes in the median eminence. In both sexes, the breeding season is associated with increased kisspeptin-ir process density in the rostral periventricular area of the third ventricle and arcuate nucleus; at the latter site, this is positively correlated with gonadal mass. Cross-species comparisons lead us to hypothesize differential mechanisms within these peptidergic systems: that increased GnRH-1 immunoreactivity during the nonbreeding season reflects increased accumulation with reduced release; that increased kisspeptin immunoreactivity during the breeding season reflects increased synthesis with increased release.
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Affiliation(s)
- Katarina Medger
- Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
| | - Nigel C Bennett
- Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
| | - Christian T Chimimba
- Department of Zoology and Entomology, DST-NRF Centre of Excellence for Invasion Biology (CIB), University of Pretoria, Pretoria, South Africa
| | - Maria K Oosthuizen
- Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
| | - Jens D Mikkelsen
- Neurobiology Research Unit, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Clive W Coen
- Reproductive Neurobiology, Division of Women's Health, Faculty of Life Sciences & Medicine, King's College London, London, United Kingdom
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Macías-Cruz U, Vicente-Pérez R, López-Baca MA, González-Ríos H, Correa-Calderón A, Arechiga CF, Avendaño-Reyes L. Effects of dietary ferulic acid on reproductive function and metabolism of pre-pubertal hairbreed ewes during the anestrous season. Theriogenology 2018; 119:220-224. [PMID: 30053723 DOI: 10.1016/j.theriogenology.2018.07.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 07/13/2018] [Accepted: 07/14/2018] [Indexed: 11/19/2022]
Abstract
This study aimed to evaluate the effects of dietary supplementation of ferulic acid (FA) on reproductive tract weight (RTW), ovarian activity and serum concentrations of some metabolites and thyroid hormones of pre-pubertal hairbreed ewe lambs during the natural anestrous season. Twenty Dorper x Pelibuey crossbred ewe lambs (initial body weight = 28.5 ± 0.5 kg and age = 5.0 mo) were fed a basal diet and assigned to two treatments (n = 10) under randomized complete block design: FA supplementation to dosages of 0 (control) or 300 mg of FA/d animal-1. Females were treated with FA during 34 d and then slaughtered to evaluate RTW and ovary. Blood samples were collected at days 1 and 34 to determine serum concentrations of metabolites (i.e. glucose, cholesterol, triglycerides, urea and total protein) and thyroid hormones. Final weight, dry matter intake, and serum concentrations of metabolites (except glucose) and thyroid hormones were unaltered by FA. Compared to control, FA-fed ewe lambs had lower (P = 0.05) serum glucose level but higher (P ≤ 0.05) RTW, ovarian mass, number of larger follicles and corpus luteum (CL). While percentage of ewe lambs with small follicles and number of small follicles per female did not vary, percentage of ewe lambs with large follicles and CL increased (P = 0.02) with FA. In conclusion, FA supplementation improves the reproductive tract development and ovarian activity of pre-pubertal hairbreed ewe lambs during the natural anestrous season. An improvement in functionality of the glucose-insulin system could be related with this benefic effect of FA.
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Affiliation(s)
- U Macías-Cruz
- Universidad Autónoma de Baja California, Instituto de Ciencias Agrícolas, Valle de Mexicali, B.C., 21705, Mexico
| | - R Vicente-Pérez
- Universidad Autónoma de Baja California, Instituto de Ciencias Agrícolas, Valle de Mexicali, B.C., 21705, Mexico; Universidad de Guadalajara, Centro Universitario de la Costa Sur, Autlán de Navarro, Jalisco, 48900, Mexico
| | - M A López-Baca
- Centro de Investigación en Alimentación y Desarrollo, A.C., Hermosillo, Sonora, 83000, Mexico
| | - H González-Ríos
- Centro de Investigación en Alimentación y Desarrollo, A.C., Hermosillo, Sonora, 83000, Mexico
| | - A Correa-Calderón
- Universidad Autónoma de Baja California, Instituto de Ciencias Agrícolas, Valle de Mexicali, B.C., 21705, Mexico
| | - C F Arechiga
- Universidad Autónoma de Zacatecas, Unidad Académica de Medicina Veterinaria y Zootecnia, Carretera Panamerica Zacateca-Fresnillo km 31.5, Zacatecas, 98500, Mexico
| | - L Avendaño-Reyes
- Universidad Autónoma de Baja California, Instituto de Ciencias Agrícolas, Valle de Mexicali, B.C., 21705, Mexico.
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8
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Annual reproductive activity of ewes from Jezersko-Solchava, Bovec and Istrian breeds under variable field conditions. Small Rumin Res 2017. [DOI: 10.1016/j.smallrumres.2017.02.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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9
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Relationships between leptin, KiSS-1/GPR54 expression and TSH secretion from pituitary cells of pubertal ewes in vitro. Res Vet Sci 2016; 105:180-7. [PMID: 27033929 DOI: 10.1016/j.rvsc.2016.02.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Revised: 02/08/2016] [Accepted: 02/21/2016] [Indexed: 11/22/2022]
Abstract
Kisspeptin and leptin play a crucial role in the puberty of sheep as they initiate the activity of hypothalamic-pituitary-ovarian axis. Also hormones of thyrotropic axis are probably involved in this process. The aim of study was to analyze the impact of leptin on kisspeptin-10 secretion as well as kisspeptin-1 and G protein-coupled receptor (GPR54) mRNA expression in pituitary cells of pubertal ewes in vitro. The influence of kisspeptin on TSH secretion was also examined. Cells were cultured in McCoy's 5A medium without hormones; with 10(-10)-10(-5)M of leptin; with 10(-11)-10(-5)M of kisspeptin-10; with peptide 234 (10(-7)M, antagonist of GPR54) or 10(-11)-10(-5)M of kisspeptin-10 and peptide 234. Then, kisspeptin-10 and TSH secretion as well as KiSS-1 and GPR54 expression were analyzed. We found that leptin directly affected kisspeptin-10 secretion and kisspeptin-1/GPR54 expression in pituitary cells of pubertal ewes. Kisspeptin-10 did not change TSH secretion, except exerting a short-term influence after 2h.
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10
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Ebling FJP. Hypothalamic control of seasonal changes in food intake and body weight. Front Neuroendocrinol 2015; 37:97-107. [PMID: 25449796 DOI: 10.1016/j.yfrne.2014.10.003] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Revised: 10/15/2014] [Accepted: 10/17/2014] [Indexed: 12/22/2022]
Abstract
Seasonal cycles of fattening and body weight reflecting changes in both food intake and energy expenditure are a core aspect of the biology of mammals that have evolved in temperate and arctic latitudes. Identifying the neuroendocrine mechanisms that underlie these cycles has provided new insights into the hypothalamic control of appetite and fuel oxidation. Surprisingly, seasonal cycles do not result from changes in the leptin-responsive and homeostatic pathways located in the mediobasal and lateral hypothalamus that regulate meal timing and compensatory responses to starvation or caloric restriction. Rather, they result from changes in tanycyte function, which locally regulates transport and metabolism of thyroid hormone and retinoic acid. These signals are crucial for the initial development of the brain, so it is hypothesized that seasonal neuroendocrine cycles reflect developmental mechanisms in the adult hypothalamus, manifest as changes in neurogenesis and plasticity of connections.
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Affiliation(s)
- Francis J P Ebling
- School of Life Sciences, University of Nottingham Medical School, Queen's Medical Centre, Nottingham NG7 2UH, UK.
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11
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Park SU, Bernstein AN, Place NJ. Complementary histological and genomic analyses reveal marked differences in the developmental trajectories of ovaries in Siberian hamsters raised in long- and short-day lengths. Mol Reprod Dev 2014; 81:248-56. [DOI: 10.1002/mrd.22292] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Accepted: 12/08/2013] [Indexed: 11/12/2022]
Affiliation(s)
- Sung-Un Park
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine; Cornell University; Ithaca New York
| | - Adrien N. Bernstein
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine; Cornell University; Ithaca New York
| | - Ned J. Place
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine; Cornell University; Ithaca New York
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12
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Dardente H, Hazlerigg DG, Ebling FJP. Thyroid hormone and seasonal rhythmicity. Front Endocrinol (Lausanne) 2014; 5:19. [PMID: 24616714 PMCID: PMC3935485 DOI: 10.3389/fendo.2014.00019] [Citation(s) in RCA: 124] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Accepted: 02/10/2014] [Indexed: 12/15/2022] Open
Abstract
Living organisms show seasonality in a wide array of functions such as reproduction, fattening, hibernation, and migration. At temperate latitudes, changes in photoperiod maintain the alignment of annual rhythms with predictable changes in the environment. The appropriate physiological response to changing photoperiod in mammals requires retinal detection of light and pineal secretion of melatonin, but extraretinal detection of light occurs in birds. A common mechanism across all vertebrates is that these photoperiod-regulated systems alter hypothalamic thyroid hormone (TH) conversion. Here, we review the evidence that a circadian clock within the pars tuberalis of the adenohypophysis links photoperiod decoding to local changes of TH signaling within the medio-basal hypothalamus (MBH) through a conserved thyrotropin/deiodinase axis. We also focus on recent findings which indicate that, beyond the photoperiodic control of its conversion, TH might also be involved in longer-term timing processes of seasonal programs. Finally, we examine the potential implication of kisspeptin and RFRP3, two RF-amide peptides expressed within the MBH, in seasonal rhythmicity.
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Affiliation(s)
- Hugues Dardente
- Physiologie de la Reproduction et des Comportements, INRA, UMR085, Nouzilly, France
- CNRS, UMR7247, Nouzilly, France
- Université François Rabelais de Tours, Tours, France
- Institut français du cheval et de l’équitation, Nouzilly, France
- *Correspondence: Hugues Dardente, INRA, UMR85 Physiologie de la Reproduction et des Comportements, CNRS, UMR7247, Université François Rabelais de Tours, IFCE, F-37380 Nouzilly, France e-mail:
| | - David G. Hazlerigg
- Department of Arctic and Marine Biology, University of Tromsø, Tromsø, Norway
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Zhou S, Holmes MM, Forger NG, Goldman BD, Lovern MB, Caraty A, Kalló I, Faulkes CG, Coen CW. Socially regulated reproductive development: Analysis of GnRH-1 and kisspeptin neuronal systems in cooperatively breeding naked mole-rats (Heterocephalus glaber). J Comp Neurol 2013; 521:3003-29. [DOI: 10.1002/cne.23327] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2012] [Revised: 02/20/2013] [Accepted: 02/26/2013] [Indexed: 12/18/2022]
Affiliation(s)
- Shuzhi Zhou
- Reproductive Neurobiology; Division of Women's Health; School of Medicine; King's College London; London; UK
| | | | | | | | | | - Alain Caraty
- INRA; Physiology of Reproduction; Nouzilly; France
| | | | | | - Clive W. Coen
- Reproductive Neurobiology; Division of Women's Health; School of Medicine; King's College London; London; UK
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14
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Affiliation(s)
- Francis J P Ebling
- School of Biomedical Sciences, University of Nottingham Medical School, Queen's Medical Centre, Nottingham NG7 2UH, UK.
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15
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Bolborea M, Dale N. Hypothalamic tanycytes: potential roles in the control of feeding and energy balance. Trends Neurosci 2013; 36:91-100. [PMID: 23332797 PMCID: PMC3605593 DOI: 10.1016/j.tins.2012.12.008] [Citation(s) in RCA: 210] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Revised: 12/11/2012] [Accepted: 12/18/2012] [Indexed: 02/08/2023]
Abstract
Tanycytes, glial-like cells that line the third ventricle, are emerging as components of the hypothalamic networks that control body weight and energy balance. They contact the cerebrospinal fluid (CSF) and send processes that come into close contact with neurons in the arcuate and ventromedial hypothalamic nuclei. Tanycytes are glucosensitive and are able to respond to transmitters associated with arousal and the drive to feed. At least some tanycytes are stem cells and, in the median eminence, may be stimulated by diet to generate new neurons. The quest is on to understand how tanycytes detect and respond to changes in energy balance and how they communicate with the rest of the nervous system to effect their functions.
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Affiliation(s)
- Matei Bolborea
- School of Life Sciences, University of Warwick, Coventry, UK
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16
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Analysis on DNA sequence of TSHB gene and its association with reproductive seasonality in goats. Mol Biol Rep 2012; 40:1893-904. [PMID: 23076536 DOI: 10.1007/s11033-012-2245-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2012] [Accepted: 10/10/2012] [Indexed: 12/15/2022]
Abstract
Thyroid stimulating hormone beta chain (TSHB) is mainly expressed in pituitary and its expression is closely related to photoperiodic control of seasonal reproduction in animals. In the present study, ten primer pairs have been used to clone the DNA sequence and to detect genetic mutations of goat TSHB gene. Two DNA fragments of goat TSHB gene were obtained, which were 2,614 and 1,031 bp in length, respectively. They comprised about 2.5 kb 5' regulatory region, all of the three exons and two introns. Goat TSHB gene has a coding region of 417 bp, encoding 138 amino acids which was predicted to be a secretory protein with a signal peptide of 16 amino acids. The sequence of TSHB gene is highly conserved among mammals. In addition, five mutations (C53A, 3 bp Indel at the 287-289 locus, 34 bp Indel at the 584-617 locus, A1819C and E2_72TA) were found in goat TSHB gene and they were shown to be in strong linkage disequilibrium. Interestingly, the genotype distributions for both single locus and haplotype have shown to be significant different between seasonal and nonseasonal goat breeds. And haplotype H2 and diplotype H2/H4 may be related to year-round estrus. We preliminarily presumed that the five closely linked mutations of goat TSHB gene may be part of the causal sources for the diversities of reproductive seasonality in goats. Our study may provide a possible efficient genetic way to decrease seasonality in goats.
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Abstract
It has long been known that thyroid hormone has profound direct effects on metabolism and cardiovascular function. More recently, it was shown that the hormone also modulates these systems by actions on the central autonomic control. Recent studies that either manipulated thyroid hormone signalling in anatomical areas of the brain or analysed seasonal models with an endogenous fluctuation in hypothalamic thyroid hormone levels revealed that the hormone controls energy turnover. However, most of these studies did not progress beyond the level of anatomical nuclei; thus, the neuronal substrates as well as the molecular mechanisms remain largely enigmatic. This review summarises the evidence for a role of thyroid hormone in the central autonomic control of peripheral homeostasis and advocates novel strategies to address thyroid hormone action in the brain on a cellular level.
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Affiliation(s)
- Amy Warner
- Department of Cell and Molecular Biology, Karolinska Institutet, 17177 Stockholm, Sweden
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Duffield GE, Mikkelsen JD, Ebling FJP. Conserved expression of the glutamate NMDA receptor 1 subunit splice variants during the development of the Siberian hamster suprachiasmatic nucleus. PLoS One 2012; 7:e37496. [PMID: 22675426 PMCID: PMC3365105 DOI: 10.1371/journal.pone.0037496] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2011] [Accepted: 04/23/2012] [Indexed: 11/19/2022] Open
Abstract
Glutamate neurotransmission and the N-methyl-D-aspartate receptor (NMDAR) are central to photic signaling to the master circadian pacemaker located in the hypothalamic suprachiasmatic nucleus (SCN). NMDARs also play important roles in brain development including visual input circuits. The functional NMDAR is comprised of multiple subunits, but each requiring the NR1 subunit for normal activity. The NR1 can be alternatively spliced to produce isoforms that confer different functional properties on the NMDAR. The SCN undergoes extensive developmental changes during postnatal life, including synaptogenesis and acquisition of photic signaling. These changes are especially important in the highly photoperiodic Siberian hamster, in which development of sensitivity to photic cues within the SCN could impact early physiological programming. In this study we examined the expression of NR1 isoforms in the hamster at different developmental ages. Gene expression in the forebrain was quantified by in situ hybridization using oligonucleotide probes specific to alternatively spliced regions of the NR1 heteronuclear mRNA, including examination of anterior hypothalamus, piriform cortex, caudate-putamen, thalamus and hippocampus. Gene expression analysis within the SCN revealed the absence of the N1 cassette, the presence of the C2 cassette alone and the combined absence of C1 and C2 cassettes, indicating that the dominant splice variants are NR1-2a and NR1-4a. Whilst we observe changes at different developmental ages in levels of NR1 isoform probe hybridization in various forebrain structures, we find no significant changes within the SCN. This suggests that a switch in NR1 isoform does not underlie or is not produced by developmental changes within the hamster SCN. Consistency of the NR1 isoforms would ensure that the response of the SCN cells to photic signals remains stable throughout life, an important aspect of the function of the SCN as a responder to environmental changes in quality/quantity of light over the circadian day and annual cycle.
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Affiliation(s)
- Giles E Duffield
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, United States of America.
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Valasi I, Chadio S, Fthenakis G, Amiridis G. Management of pre-pubertal small ruminants: Physiological basis and clinical approach. Anim Reprod Sci 2012; 130:126-34. [DOI: 10.1016/j.anireprosci.2012.01.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Tolson KP, Chappell PE. The Changes They are A-Timed: Metabolism, Endogenous Clocks, and the Timing of Puberty. Front Endocrinol (Lausanne) 2012; 3:45. [PMID: 22645521 PMCID: PMC3355854 DOI: 10.3389/fendo.2012.00045] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2011] [Accepted: 03/08/2012] [Indexed: 11/16/2022] Open
Abstract
Childhood obesity has increased dramatically over the last several decades, particularly in industrialized countries, often accompanied by acceleration of pubertal progression and associated reproductive abnormalities (Biro et al., 2006; Rosenfield et al., 2009). The timing of pubertal initiation and progression in mammals is likely influenced by nutritional and metabolic state, leading to the hypothesis that deviations from normal metabolic rate, such as those seen in obesity, may contribute to observed alterations in the rate of pubertal progression. While several recent reviews have addressed the effects of metabolic disorders on reproductive function in general, this review will explore previous and current models of pubertal timing, outlining a potential role of endogenous timing mechanisms such as cellular circadian clocks in the initiation of puberty, and how these clocks might be altered by metabolic factors. Additionally, we will examine recently elucidated neuroendocrine regulators of pubertal progression such as kisspeptin, explore models detailing how the mammalian reproductive axis is silenced during the juvenile period and reactivated at appropriate developmental times, and emphasize how metabolic dysfunction such as childhood obesity may alter timing cues that advance or delay pubertal progression, resulting in diminished reproductive capacity.
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Affiliation(s)
- Kristen P. Tolson
- Department of Biomedical Sciences, College of Veterinary Medicine, Oregon State UniversityCorvallis, OR, USA
| | - Patrick E. Chappell
- Department of Biomedical Sciences, College of Veterinary Medicine, Oregon State UniversityCorvallis, OR, USA
- *Correspondence: Patrick E. Chappell, Department of Biomedical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR 97331, USA. e-mail:
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Murphy M, Jethwa PH, Warner A, Barrett P, Nilaweera KN, Brameld JM, Ebling FJP. Effects of manipulating hypothalamic triiodothyronine concentrations on seasonal body weight and torpor cycles in Siberian hamsters. Endocrinology 2012; 153:101-12. [PMID: 22028444 DOI: 10.1210/en.2011-1249] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Siberian hamsters display photoperiodically regulated annual cycles in body weight, appetite, and reproduction. Previous studies have revealed a profound up-regulation of type 3 deiodinase (DIO3) mRNA in the ventral ependyma of the hypothalamus associated with hypophagia and weight loss in short-day photoperiods. DIO3 reduces the local availability of T(3), so the aim of this study was to test the hypothesis that decreased hypothalamic T(3) availability underlies the short-day-induced catabolic state. The experimental approach was to determine whether a local increase in T(3) in the hypothalamus of hamsters exposed to short days could reverse the behavioral and physiological changes induced by this photoperiod. In study 1, microimplants releasing T(3) were placed bilaterally into the hypothalamus. This treatment rapidly induced a long-day phenotype including increased appetite and body weight within 3 wk of treatment and increased fat mass and testis size by the end of the 10-wk study period. In study 2, hypothalamic T(3) implants were placed into hamsters carrying abdominal radiotelemetry implants. Again body weight increased significantly, and the occurrence of winter torpor bouts was dramatically decreased to less than one bout per week, whereas sham-implanted hamsters entered torpor up to six times a week. Our findings demonstrate that increased central T(3) induces a long-day metabolic phenotype, but in neither study was the molt cycle affected, so we infer that we had not disrupted the initial detection of photoperiod. We conclude that hypothalamic thyroid hormone availability plays a key role in seasonal regulation of appetite, body weight, and torpor.
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Affiliation(s)
- Michelle Murphy
- School of Biomedical Sciences, University of Nottingham Medical School, Queen's Medical Centre, Nottingham NG7 2UH, United Kingdom
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22
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Research progress in molecular mechanism of animal seasonal reproduction. YI CHUAN = HEREDITAS 2011; 33:695-706. [DOI: 10.3724/sp.j.1005.2011.00695] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Murphy M, Ebling FJP. The role of hypothalamic tri-iodothyronine availability in seasonal regulation of energy balance and body weight. J Thyroid Res 2011; 2011:387562. [PMID: 21765988 PMCID: PMC3134268 DOI: 10.4061/2011/387562] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2011] [Revised: 04/07/2011] [Accepted: 04/27/2011] [Indexed: 11/20/2022] Open
Abstract
Seasonal cycles of body weight provide a natural model system to understand the central control of energy balance. Studies of such cycles in Siberian hamsters suggest that a change in the hypothalamic availability of thyroid hormone is the key determinant of annual weight regulation. Uptake of thyroid hormone into the hypothalamus from the peripheral circulation occurs largely through a specific monocarboxylate transporter expressed by tanycyte cells lining the third ventricle. Tanycytes are the principal brain cell type expressing type II and type III deiodinases, so they control the local concentrations of T4, T3, and inactive metabolites. Type III deiodinase mRNA in tanycytes is photoperiodically upregulated in short photoperiod. This would be expected to reduce the availability of T3 in the hypothalamus by promoting the production of inactive metabolites such as rT3. Experimental microimplantation of T3 directly into the hypothalamus during short-days promotes a long-day phenotype by increasing food intake and body weight without affecting the peripheral thyroid axis. Thus, thyroid hormone exerts anabolic actions within the brain that play a key role in the seasonal regulation of body weight. Understanding the precise actions of thyroid hormone in the brain may identify novel targets for long-term pharmacological manipulation of body weight.
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Affiliation(s)
- Michelle Murphy
- School of Biomedical Sciences, Queen's Medical Centre, University of Nottingham Medical School, Nottingham NG7 2UH, UK
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Dale N. Purinergic signaling in hypothalamic tanycytes: potential roles in chemosensing. Semin Cell Dev Biol 2011; 22:237-44. [PMID: 21396904 DOI: 10.1016/j.semcdb.2011.02.024] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2010] [Revised: 02/10/2011] [Accepted: 02/24/2011] [Indexed: 12/26/2022]
Abstract
Hypothalamic tanycytes are cells that line the walls of the 3rd ventricle. Their cell bodies contact the cerebrospinal fluid and give rise to an inwardly directed process. The more dorsally located (α1 and α2) tanycytes project to areas of the brain involved in the control of feeding and energy balance (the arcuate nucleus and ventromedial hypothalamic nucleus). Although their functions are poorly understood, they have some similarities to glial cells. Recent evidence shows that they express key molecules involved in purinergic signaling and at least some tanycytes may act as adult multipotent stem cells. Emerging evidence suggests that tanycytes signal through changes in intracellular Ca(2+) and that they can respond with large Ca(2+) signals to ATP and transmitters associated with wakefulness and the drive to feed. They are also glucosensitive and this response is dependent on release of ATP from tanycytes and the activation of P2Y1 receptors. Their ability to release ATP gives potential for their integration into the hypothalamic circuitry controlling energy balance and feeding, but many fundamental questions about their possible functions and roles remain unanswered.
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Affiliation(s)
- Nicholas Dale
- School of Life Sciences, University of Warwick, Coventry, United Kingdom.
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25
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Mann DR, Plant TM. The role and potential sites of action of thyroid hormone in timing the onset of puberty in male primates. Brain Res 2010; 1364:175-85. [PMID: 20883669 PMCID: PMC2992600 DOI: 10.1016/j.brainres.2010.09.082] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2010] [Revised: 09/14/2010] [Accepted: 09/22/2010] [Indexed: 11/19/2022]
Abstract
Puberty in primates is first delayed by a neurobiological switch that arrests pulsatile GnRH release during infancy and then triggered, after a protracted period of juvenile development, by resurgence in intermittent release of this hypothalamic peptide. The purpose of this chapter is to review recent studies conducted in our laboratories to begin to examine the role of thyroid hormone (TH) in governing this postnatal development of pulsatile GnRH release in primates and therefore the timing of puberty in these species. The male rhesus monkey was used as the experimental model and TH activity was manipulated by surgical and chemical thyroidectomy on the one hand, and by thyroxine (T(4)) and triiodothyronine (T(3)) replacement on the other. Our results indicate that the resurgence in pulsatile GnRH release at the termination of the juvenile phase of development is dependent on a permissive action of TH. Whether this action of TH is mediated directly on hypothalamic centers regulating the pulsatile release of GnRH, or indirectly by circulating signals reflecting TH action on somatic development remains to be determined.
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Affiliation(s)
- David R Mann
- Department of Physiology, Morehouse School of Medicine, 720 Westview Drive SW, Atlanta, GA 30310, USA.
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