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Sullivan AI, Potthoff MJ, Flippo KH. Tany-Seq: Integrated Analysis of the Mouse Tanycyte Transcriptome. Cells 2022; 11:1565. [PMID: 35563871 PMCID: PMC9104898 DOI: 10.3390/cells11091565] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 04/27/2022] [Accepted: 05/04/2022] [Indexed: 02/01/2023] Open
Abstract
The ability to maintain energy homeostasis is necessary for survival. Recently, an emerging role for ependymogial cells, which line the third ventricle in the hypothalamus in the regulation of energy homeostasis, has been appreciated. These cells are called tanycytes and are physically at the interface of brain communication with peripheral organs and have been proposed to mediate the transport of circulating hormones from the third ventricle into the parenchyma of the hypothalamus. Despite the important role tanycytes have been proposed to play in mediating communication from the periphery to the brain, we understand very little about the ontology and function of these cells due to their limited abundance and lack of ability to genetically target this cell population reliably. To overcome these hurdles, we integrated existing hypothalamic single cell RNA sequencing data, focusing on tanycytes, to allow for more in-depth characterization of tanycytic cell types and their putative functions. Overall, we expect this dataset to serve as a resource for the research community.
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Affiliation(s)
- Andrew I. Sullivan
- Department of Neuroscience and Pharmacology, College of Medicine, University of Iowa Carver, Iowa City, IA 52242, USA; (A.I.S.); (M.J.P.)
- Fraternal Order of Eagles Diabetes Research Center, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
- Iowa Neuroscience Institute, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Matthew J. Potthoff
- Department of Neuroscience and Pharmacology, College of Medicine, University of Iowa Carver, Iowa City, IA 52242, USA; (A.I.S.); (M.J.P.)
- Fraternal Order of Eagles Diabetes Research Center, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
- Iowa Neuroscience Institute, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
- Department of Veterans Affairs Medical Center, Iowa City, IA 52242, USA
| | - Kyle H. Flippo
- Department of Neuroscience and Pharmacology, College of Medicine, University of Iowa Carver, Iowa City, IA 52242, USA; (A.I.S.); (M.J.P.)
- Fraternal Order of Eagles Diabetes Research Center, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
- Iowa Neuroscience Institute, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
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2
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Yao W, Liu W, Deng K, Wang Z, Wang DH, Zhang XY. GnRH expression and cell proliferation are associated with seasonal breeding and food hoarding in Mongolian gerbils (Meriones unguiculatus). Horm Behav 2019; 112:42-53. [PMID: 30922890 DOI: 10.1016/j.yhbeh.2019.03.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Revised: 03/18/2019] [Accepted: 03/22/2019] [Indexed: 12/14/2022]
Abstract
Seasonal brain plasticity contributes to a variety of physiological and behavioral processes. We hypothesized that variations in GnRH expression and cell proliferation facilitated seasonal breeding and food hoarding. Here, we reported seasonal changes in sexual and social behavior, GnRH expression and brain cell proliferation, and the role of photoperiod in inducing seasonal breeding and brain plasticity in Mongolian gerbils (Meriones unguiculatus). The gerbils captured in April and July had more mature sexual development, higher exploratory behavior, and preferred novelty much more than those captured in September. Male gerbils captured in April and July had consistently higher GnRH expression than those captured in September. GnRH expression was also found to be suppressed by food-induced hoarding behavior in the breeding season. Both subadult and adult gerbils from April and July had higher cell proliferation in SVZ, hypothalamus and amygdala compared to those in September. However, adult gerbils captured in September preferred familiar objects, and no seasonal differences were found in cell proliferation in hippocampal dentate gyrus among the three seasons. The laboratory study showed that photoperiod alone did not alter reproductive traits, behavior, cell proliferation or cell survival in the detected brain regions. These findings suggest that the structural variations in GnRH expression in hypothalamus and cell proliferation in hypothalamus, amygdala and hippocampus are associated with seasonal breeding and food hoarding in gerbils. It gives a new insight into the proximate physiological and neural basis for these seasonal life-history traits of breeding and food hoarding in small mammals.
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Affiliation(s)
- Wei Yao
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; Institute of Health Sciences, Anhui University, Hefei, Anhui 230601, China
| | - Wei Liu
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ke Deng
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Zuoxin Wang
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, FL 32306-1270, USA
| | - De-Hua Wang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Xue-Ying Zhang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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3
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Cázarez-Márquez F, Milesi S, Laran-Chich MP, Klosen P, Kalsbeek A, Simonneaux V. Kisspeptin and RFRP3 modulate body mass in Phodopus sungorus via two different neuroendocrine pathways. J Neuroendocrinol 2019; 31:e12710. [PMID: 30887598 DOI: 10.1111/jne.12710] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Revised: 03/09/2019] [Accepted: 03/14/2019] [Indexed: 01/15/2023]
Abstract
Many animals exhibit remarkable metabolic and reproductive adaptations to seasonal changes in their environment. When day length shortens, Djungarian hamsters (Phodopus sungorus) reduce their body weight and inhibit their reproductive activity, whereas the opposite occurs in springtime. These physiological adaptations are considered to depend on photoperiodic changes in hypothalamic genes encoding the peptides kisspeptin (Kp) and RFamide-related peptide 3 (RFRP3) for the control of reproduction, as well as pro-opiomelanocortin and somatostatin for metabolic regulation. The present study investigates the effect of Kp and RFRP3 on long-term body weight regulation, aiming to establish whether metabolic and reproductive hypothalamic networks may interact during adaptation to seasonal physiology. We found that chronic central administration of both Kp and RFRP3 in short photoperiod-adapted male Djungarian hamsters increased body weight, although via different pathways. The effect of Kp was dependent on testicular activity because castration prevented the body weight increase and was associated with an increase in pro-opiomelanocortin and neuropeptide Y expression. On the other hand, the orexigenic effect of RFRP3 was associated with an increase in circulating insulin and leptin levels, although it had no effect on any of the hypothalamic metabolic genes investigated, and did not change circulating levels of sex steroids. Notably, neither Kp, nor RFRP3 altered female hamster metabolic parameters. Thus, using a rodent model exhibiting seasonal changes in reproduction and metabolism, the present study demonstrates that, in addition to its role in the central control of reproduction, Kp also participates in body weight control in a sex-dependent manner via an anabolic action of testosterone. Conversely, RFRP3 affects body weight control in males mostly by acting on adiposity, with no overt effect on the reproductive system in both sexes.
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Affiliation(s)
- Fernando Cázarez-Márquez
- Institute of Cellular and Integrative Neurosciences (INCI), Strasbourg, France
- Netherlands Institute for Neuroscience (NIN), Amsterdam, The Netherlands
- Laboratory of Endocrinology, Amsterdam Gastroenterology & Metabolism, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Sebastien Milesi
- Institute of Cellular and Integrative Neurosciences (INCI), Strasbourg, France
| | | | - Paul Klosen
- Institute of Cellular and Integrative Neurosciences (INCI), Strasbourg, France
| | - Andries Kalsbeek
- Netherlands Institute for Neuroscience (NIN), Amsterdam, The Netherlands
- Laboratory of Endocrinology, Amsterdam Gastroenterology & Metabolism, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
- Department of Endocrinology and Metabolism, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Valérie Simonneaux
- Institute of Cellular and Integrative Neurosciences (INCI), Strasbourg, France
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4
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Langlet F. Tanycyte Gene Expression Dynamics in the Regulation of Energy Homeostasis. Front Endocrinol (Lausanne) 2019; 10:286. [PMID: 31133987 PMCID: PMC6514105 DOI: 10.3389/fendo.2019.00286] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Accepted: 04/18/2019] [Indexed: 01/01/2023] Open
Abstract
Animal survival relies on a constant balance between energy supply and energy expenditure, which is controlled by several neuroendocrine functions that integrate metabolic information and adapt the response of the organism to physiological demands. Polarized ependymoglial cells lining the floor of the third ventricle and sending a single process within metabolic hypothalamic parenchyma, tanycytes are henceforth described as key components of the hypothalamic neural network controlling energy balance. Their strategic position and peculiar properties convey them diverse physiological functions ranging from blood/brain traffic controllers, metabolic modulators, and neural stem/progenitor cells. At the molecular level, these functions rely on an accurate regulation of gene expression. Indeed, tanycytes are characterized by their own molecular signature which is mostly associated to their diverse physiological functions, and the detection of variations in nutrient/hormone levels leads to an adequate modulation of genetic profile in order to ensure energy homeostasis. The aim of this review is to summarize recent knowledge on the nutritional control of tanycyte gene expression.
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Boswell T, Dunn IC. Regulation of Agouti-Related Protein and Pro-Opiomelanocortin Gene Expression in the Avian Arcuate Nucleus. Front Endocrinol (Lausanne) 2017; 8:75. [PMID: 28450851 PMCID: PMC5389969 DOI: 10.3389/fendo.2017.00075] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Accepted: 03/27/2017] [Indexed: 12/25/2022] Open
Abstract
The arcuate nucleus is generally conserved across vertebrate taxa in its neuroanatomy and neuropeptide expression. Gene expression of agouti-related protein (AGRP), neuropeptide Y (NPY), pro-opiomelanocortin (POMC), and cocaine- and amphetamine-regulated transcript (CART) has been established in the arcuate nucleus of several bird species and co-localization demonstrated for AGRP and NPY. The proteins encoded by these genes exert comparable effects on food intake in birds after central administration to those seen in other vertebrates, with AGRP and NPY being orexigenic and CART and α-melanocyte-stimulating hormone anorexigenic. We have focused on the measurement of arcuate nucleus AGRP and POMC expression in several avian models in relation to the regulation of energy balance, incubation, stress, and growth. AGRP mRNA and POMC mRNA are, respectively, up- and downregulated after energy deprivation and restriction. This suggests that coordinated changes in the activity of AGRP and POMC neurons help to drive the homeostatic response to replace depleted energy stores in birds as in other vertebrates. While AGRP and POMC expression are generally positively and negatively correlated with food intake, respectively, we review here situations in some avian models in which AGRP gene expression is dissociated from the level of food intake and may have an influence on growth independent of changes in appetite. This suggests the possibility that the central melanocortin system exerts more pleiotropic functions in birds. While the neuroanatomical arrangement of AGRP and POMC neurons and the sensitivity of their activity to nutritional state appear generally conserved with other vertebrates, detailed knowledge is lacking of the key nutritional feedback signals acting on the avian arcuate nucleus and there appear to be significant differences between birds and mammals. In particular, recently identified avian leptin genes show differences between bird species in their tissue expression patterns and appear less closely linked in their expression to nutritional state. It is presently uncertain how the regulation of the central melanocortin system in birds is brought about in the situation of the apparently reduced importance of leptin and ghrelin compared to mammals.
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Affiliation(s)
- Timothy Boswell
- School of Biology, Newcastle University, Newcastle upon Tyne, UK
- *Correspondence: Timothy Boswell,
| | - Ian C. Dunn
- Royal (Dick) School of Veterinary Studies, Roslin Institute, University of Edinburgh, Easter Bush, UK
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6
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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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Cornelius JM, Boswell T, Jenni-Eiermann S, Breuner CW, Ramenofsky M. Contributions of endocrinology to the migration life history of birds. Gen Comp Endocrinol 2013; 190:47-60. [PMID: 23602795 DOI: 10.1016/j.ygcen.2013.03.027] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2012] [Revised: 03/24/2013] [Accepted: 03/25/2013] [Indexed: 11/29/2022]
Abstract
Migration is a key life cycle stage in nearly 2000 species of birds and is a greatly appreciated phenomenon in both cultural and academic arenas. Despite a long research tradition concerning many aspects of migration, investigations of hormonal contributions to migratory physiology and behavior are more limited and represent a comparatively young research field. We review advances in our understanding of the hormonal mechanisms of migration with particular emphasis on the sub-stages of the migration life history: development, departure, flight and arrival. These sub-stages vary widely in their behavioral, ecological and physiological contexts and, as such, should be given appropriate individual consideration.
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Affiliation(s)
- J M Cornelius
- Department of Neurobiology, Physiology and Behavior, University of California-Davis, One Shields Avenue, Davis, CA 95616, USA.
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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: 209] [Impact Index Per Article: 19.0] [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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9
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Siewiera K, Labieniec-Watala M. Ambiguous effect of dendrimer PAMAM G3 on rat heart respiration in a model of an experimental diabetes – Objective causes of laboratory misfortune or unpredictable G3 activity? Int J Pharm 2012; 430:258-65. [DOI: 10.1016/j.ijpharm.2012.03.037] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2012] [Accepted: 03/23/2012] [Indexed: 01/18/2023]
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10
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Kalló I, Mohácsik P, Vida B, Zeöld A, Bardóczi Z, Zavacki AM, Farkas E, Kádár A, Hrabovszky E, Arrojo e Drigo R, Dong L, Barna L, Palkovits M, Borsay BA, Herczeg L, Lechan RM, Bianco AC, Liposits Z, Fekete C, Gereben B. A novel pathway regulates thyroid hormone availability in rat and human hypothalamic neurosecretory neurons. PLoS One 2012; 7:e37860. [PMID: 22719854 PMCID: PMC3377717 DOI: 10.1371/journal.pone.0037860] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Accepted: 04/25/2012] [Indexed: 11/29/2022] Open
Abstract
Hypothalamic neurosecretory systems are fundamental regulatory circuits influenced by thyroid hormone. Monocarboxylate-transporter-8 (MCT8)-mediated uptake of thyroid hormone followed by type 3 deiodinase (D3)-catalyzed inactivation represent limiting regulatory factors of neuronal T3 availability. In the present study we addressed the localization and subcellular distribution of D3 and MCT8 in neurosecretory neurons and addressed D3 function in their axons. Intense D3-immunoreactivity was observed in axon varicosities in the external zone of the rat median eminence and the neurohaemal zone of the human infundibulum containing axon terminals of hypophysiotropic parvocellular neurons. Immuno-electronmicroscopy localized D3 to dense-core vesicles in hypophysiotropic axon varicosities. N-STORM-superresolution-microscopy detected the active center containing C-terminus of D3 at the outer surface of these organelles. Double-labeling immunofluorescent confocal microscopy revealed that D3 is present in the majority of GnRH, CRH and GHRH axons but only in a minority of TRH axons, while absent from somatostatin-containing neurons. Bimolecular-Fluorescence-Complementation identified D3 homodimers, a prerequisite for D3 activity, in processes of GT1-7 cells. Furthermore, T3-inducible D3 catalytic activity was detected in the rat median eminence. Triple-labeling immunofluorescence and immuno-electronmicroscopy revealed the presence of MCT8 on the surface of the vast majority of all types of hypophysiotropic terminals. The presence of MCT8 was also demonstrated on the axon terminals in the neurohaemal zone of the human infundibulum. The unexpected role of hypophysiotropic axons in fine-tuned regulation of T3 availability in these cells via MCT8-mediated transport and D3-catalyzed inactivation may represent a novel regulatory core mechanism for metabolism, growth, stress and reproduction in rodents and humans.
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Affiliation(s)
- Imre Kalló
- Department of Endocrine Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
- Department of Neuroscience, Faculty of Information Technology, Pázmány Péter Catholic University, Budapest, Hungary
| | - Petra Mohácsik
- Department of Endocrine Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
| | - Barbara Vida
- Department of Endocrine Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
| | - Anikó Zeöld
- Department of Endocrine Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
| | - Zsuzsanna Bardóczi
- Department of Endocrine Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
| | - Ann Marie Zavacki
- Thyroid Section, Division of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Erzsébet Farkas
- Department of Endocrine Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
| | - Andrea Kádár
- Department of Endocrine Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
| | - Erik Hrabovszky
- Department of Endocrine Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
| | - Rafael Arrojo e Drigo
- Division of Endocrinology, Diabetes and Metabolism, University of Miami Miller School of Medicine Miami, Florida, United States of America
| | - Liping Dong
- Division of Endocrinology, Diabetes and Metabolism, University of Miami Miller School of Medicine Miami, Florida, United States of America
| | - László Barna
- Nikon Microscopy Center, Institute of Experimental Medicine, Budapest, Hungary
| | - Miklós Palkovits
- Human Brain Tissue Bank, Semmelweis University, Budapest, Hungary
| | - Beáta A. Borsay
- Department of Forensic Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - László Herczeg
- Department of Forensic Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Ronald M. Lechan
- Tupper Research Institute and Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, Boston, Tufts Medical Center, Boston, Massachusetts, United States of America
| | - Antonio C. Bianco
- Division of Endocrinology, Diabetes and Metabolism, University of Miami Miller School of Medicine Miami, Florida, United States of America
| | - Zsolt Liposits
- Department of Endocrine Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
- Department of Neuroscience, Faculty of Information Technology, Pázmány Péter Catholic University, Budapest, Hungary
| | - Csaba Fekete
- Department of Endocrine Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
- Tupper Research Institute and Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, Boston, Tufts Medical Center, Boston, Massachusetts, United States of America
| | - Balázs Gereben
- Department of Endocrine Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
- Division of Endocrinology, Diabetes and Metabolism, University of Miami Miller School of Medicine Miami, Florida, United States of America
- * E-mail:
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Skipor J, Młynarczuk J, Szczepkowska A, Lagaraine C, Grochowalski A, Guillaume D, Dufourny L, Thiéry JC. Photoperiod modulates access of 2,2',4,4',5,5'-hexachlorobiphenyl (PCB153) to the brain and its effect on gonadotropin and thyroid hormones in adult ewes. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2012; 78:336-343. [PMID: 22197259 DOI: 10.1016/j.ecoenv.2011.11.042] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2011] [Revised: 11/28/2011] [Accepted: 11/29/2011] [Indexed: 05/31/2023]
Abstract
The effects of photoperiod on the cerebrospinal fluid (CSF) concentration of six ortho-substituted polychlorinated biphenyls (PCBs: PCB28, PCB52, PCB101, PCB138, PCB153, and PCB180), the effects of an orally administered low dose of PCB153 (0.3mg/kg, three times a week for three weeks) on PCBs and thyroid hormones (THs) concentrations in the CSF and plasma, and the release of luteinizing hormone (LH) were determined in ovariectomized, estradiol-implanted ewes (2.5 years old) maintained indoors under artificial long day (LD, 16L: 8D) and short day (SD, 8L: 16D) conditions. Concentrations of two PCBs (PCB28 and PCB153) in the plasma and four PCBs in the CSF (PCB101, PCB138, PCB153, and PCB180) were significantly higher during LD than SD. Following PCB153 treatment, its concentration in the plasma was higher in SD (1.2 ± 0.3 ng/ml) than LD (0.2 ± 0.05 ng/ml), but similar in the CSF (10.2 ± 3.7 pg/ml vs. 13 ± 0.7 pg/ml) under both photoperiods. During SD, the concentration of PCB153 in the CSF was higher in treated animals than controls, while no differences were noted under LD. These findings indicate that in ewes, exposure of the brain to more highly chlorinated, ortho-substituted PCBs may be modulated by photoperiod. PCB153 treatment had no effect on plasma THs, but reduced total triiodothyronine concentration during LD and free thyroxine during SD in the CSF. Under both photoperiods, PCB153 reduced basal plasma LH and reinforced the inhibition of pulsatile LH release during LD. As PCB153 reduced LH and THs (which are involved in the seasonal control of reproduction in ewes), it may have a braking effect on seasonal transitions between active and inactive phases of reproduction.
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Affiliation(s)
- Janina Skipor
- Institute of Animal Reproduction and Food Research, Polish Academy of Sciences, Olsztyn, Poland.
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12
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Florant GL, Healy JE. The regulation of food intake in mammalian hibernators: a review. J Comp Physiol B 2011; 182:451-67. [PMID: 22080368 DOI: 10.1007/s00360-011-0630-y] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2011] [Revised: 10/20/2011] [Accepted: 10/29/2011] [Indexed: 12/20/2022]
Abstract
One of the most profound hallmarks of mammalian hibernation is the dramatic reduction in food intake during the winter months. Several species of hibernator completely cease food intake (aphagia) for nearly 7 months regardless of ambient temperature and in many cases, whether or not food is available to them. Food intake regulation has been studied in mammals that hibernate for over 50 years and still little is known about the physiological mechanisms that control this important behavior in hibernators. It is well known from lesion experiments in non-hibernators that the hypothalamus is the main brain region controlling food intake and therefore body mass. In hibernators, the regulation of food intake and body mass is presumably governed by a circannual rhythm since there is a clear seasonal rhythm to food intake: animals increase food intake in the summer and early autumn, food intake declines in autumn and actually ceases in winter in many species, and resumes again in spring as food becomes available in the environment. Changes in circulating hormones (e.g., leptin, insulin, and ghrelin), nutrients (glucose, and free fatty acids), and cellular enzymes such as AMP-activated protein kinase (AMPK) have been shown to determine the activity of neurons involved in the food intake pathway. Thus, it appears likely that the food intake pathway is controlled by a variety of inputs, but is also acted upon by upstream regulators that are presumably rhythmic in nature. Current research examining the molecular mechanisms and integration of environmental signals (e.g., temperature and light) with these molecular mechanisms will hopefully shed light on how animals can turn off food intake and survive without eating for months on end.
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Affiliation(s)
- Gregory L Florant
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA.
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