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Rektor I, Schachter SC, Arya R, Arzy S, Braakman H, Brodie MJ, Brugger P, Chang BS, Guekht A, Hermann B, Hesdorffer DC, Jones-Gotman M, Kanner AM, Garcia-Larrea L, Mareš P, Mula M, Neufeld M, Risse GL, Ryvlin P, Seeck M, Tomson T, Korczyn AD. Third International Congress on Epilepsy, Brain, and Mind: Part 2. Epilepsy Behav 2015; 50:138-59. [PMID: 26264466 DOI: 10.1016/j.yebeh.2015.07.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Accepted: 07/07/2015] [Indexed: 01/01/2023]
Abstract
Epilepsy is both a disease of the brain and the mind. Here, we present the second of two papers with extended summaries of selected presentations of the Third International Congress on Epilepsy, Brain and Mind (April 3-5, 2014; Brno, Czech Republic). Humanistic, biologic, and therapeutic aspects of epilepsy, particularly those related to the mind, were discussed. The extended summaries provide current overviews of epilepsy, cognitive impairment, and treatment, including brain functional connectivity and functional organization; juvenile myoclonic epilepsy; cognitive problems in newly diagnosed epilepsy; SUDEP including studies on prevention and involvement of the serotoninergic system; aggression and antiepileptic drugs; body, mind, and brain, including pain, orientation, the "self-location", Gourmand syndrome, and obesity; euphoria, obsessions, and compulsions; and circumstantiality and psychiatric comorbidities.
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Affiliation(s)
- Ivan Rektor
- Masaryk University, Brno Epilepsy Center, St. Anne's Hospital and School of Medicine and Central European Institute of Technology (CEITEC), Brno, Czech Republic
| | - Steven C Schachter
- Consortia for Improving Medicine with Innovation and Technology, Harvard Medical School, Boston, MA, USA.
| | - Ravindra Arya
- Comprehensive Epilepsy Center, Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Shahar Arzy
- Department of Neurology, Hadassah Hebrew University Medical Center, Jerusalem, Israel; The Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Hilde Braakman
- Academic Center for Epileptology, Kempenhaeghe & Maastricht UMC, Sterkselseweg 65, 5591 VE Heeze, The Netherlands
| | | | - Peter Brugger
- Neuropsychology Unit, Department of Neurology, University Hospital Zürich, Zurich, Switzerland
| | - Bernard S Chang
- Departments of Neurology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA
| | - Alla Guekht
- Russian National Research Medical University, Moscow Research and Clinical Center for Neuropsychiatry, Moscow, Russia
| | - Bruce Hermann
- Department of Neurology, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Dale C Hesdorffer
- Gertrude H. Sergievsky Center and Department of Epidemiology, Columbia University, NY, USA
| | - Marilyn Jones-Gotman
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Canada
| | - Andres M Kanner
- Department of Neurology, University of Miami, Miller School of Medicine, Miami, FL, USA
| | - Luis Garcia-Larrea
- NeuroPain Lab, Centre for Neuroscience of Lyon, Inserm U1028, Hôpital Neurologique, 59Bd Pinel 69003 Lyon, France
| | - Pavel Mareš
- Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Marco Mula
- Epilepsy Group, Atkinson Morley Regional Neuroscience Centre, St George's Hospital & Institute of Medical and Biomedical Sciences, St George's University of London, London, UK
| | - Miri Neufeld
- EEG and Epilepsy Unit, Department of Neurology, Tel-Aviv Medical Center, Tel-Aviv University, Tel-Aviv, Israel
| | | | - Philippe Ryvlin
- Department of Clinical Neurosciences, CHUV, Lausanne, Switzerland; TIGER, Lyon's Neuroscience Research Center, INSERM U1028, CNRS5292 Lyon, France
| | - Margitta Seeck
- Neurology Service, Hòpitaux Universitaires de Genève, Genève, Switzerland
| | - Torbjörn Tomson
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Amos D Korczyn
- Sackler School of Medicine, Tel-Aviv University, Ramat-Aviv, Israel
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202
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Carmody JS, Ahmad NN, Machineni S, Lajoie S, Kaplan LM. Weight Loss After RYGB Is Independent of and Complementary to Serotonin 2C Receptor Signaling in Male Mice. Endocrinology 2015; 156:3183-91. [PMID: 26066076 PMCID: PMC4541621 DOI: 10.1210/en.2015-1226] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Roux-en-Y gastric bypass (RYGB) typically leads to substantial, long-term weight loss (WL) and diabetes remission, although there is a wide variation in response to RYGB among individual patients. Defining the pathways through which RYGB works should aid in the development of less invasive anti-obesity treatments, whereas identifying weight-regulatory pathways unengaged by RYGB could facilitate the development of therapies that complement the beneficial effects of surgery. Activation of serotonin 2C receptors (5-HT2CR) by serotonergic drugs causes WL in humans and animal models. 5-HT2CR are located on neurons that activate the melanocortin-4 receptors, which are essential for WL after RYGB. We therefore sought to determine whether 5-HT2CR signaling is also essential for metabolic effects of RYGB or whether it is a potentially complementary pathway, the activation of which could extend the benefits of RYGB. Diet-induced obese male mice deficient for the 5-HT2CR and their wild-type littermates underwent RYGB or sham operation. Both groups lost similar amounts of weight after RYGB, demonstrating that the improved metabolic phenotype after RYGB is 5-HT2CR independent. Consistent with this hypothesis, wild-type RYGB-treated mice lost additional weight after the administration of the serotonergic drugs fenfluramine and meta-chlorophenylpiperazine but not the nonserotonergic agent topiramate. The fact that RYGB does not depend on 5-HT2CR signaling suggests that there are important WL mechanisms not fully engaged by surgery that could potentially be harnessed for medical treatment. These results suggest a rational basis for designing medical-surgical combination therapies to optimize clinical outcomes by exploiting complementary physiological mechanisms of action.
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Affiliation(s)
- Jill S Carmody
- Obesity, Metabolism, and Nutrition Institute and Gastrointestinal Unit (J.S.C., N.N.A., S.M., S.L., L.M.K.), Massachusetts General Hospital, Boston, Massachusetts 02114; and Department of Medicine (J.S.C., N.N.A., S.M., L.M.K.), Harvard Medical School, Boston, Massachusetts 02115
| | - Nadia N Ahmad
- Obesity, Metabolism, and Nutrition Institute and Gastrointestinal Unit (J.S.C., N.N.A., S.M., S.L., L.M.K.), Massachusetts General Hospital, Boston, Massachusetts 02114; and Department of Medicine (J.S.C., N.N.A., S.M., L.M.K.), Harvard Medical School, Boston, Massachusetts 02115
| | - Sriram Machineni
- Obesity, Metabolism, and Nutrition Institute and Gastrointestinal Unit (J.S.C., N.N.A., S.M., S.L., L.M.K.), Massachusetts General Hospital, Boston, Massachusetts 02114; and Department of Medicine (J.S.C., N.N.A., S.M., L.M.K.), Harvard Medical School, Boston, Massachusetts 02115
| | - Scott Lajoie
- Obesity, Metabolism, and Nutrition Institute and Gastrointestinal Unit (J.S.C., N.N.A., S.M., S.L., L.M.K.), Massachusetts General Hospital, Boston, Massachusetts 02114; and Department of Medicine (J.S.C., N.N.A., S.M., L.M.K.), Harvard Medical School, Boston, Massachusetts 02115
| | - Lee M Kaplan
- Obesity, Metabolism, and Nutrition Institute and Gastrointestinal Unit (J.S.C., N.N.A., S.M., S.L., L.M.K.), Massachusetts General Hospital, Boston, Massachusetts 02114; and Department of Medicine (J.S.C., N.N.A., S.M., L.M.K.), Harvard Medical School, Boston, Massachusetts 02115
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203
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Séjourné J, Llaneza D, Kuti OJ, Page DT. Social Behavioral Deficits Coincide with the Onset of Seizure Susceptibility in Mice Lacking Serotonin Receptor 2c. PLoS One 2015; 10:e0136494. [PMID: 26308619 PMCID: PMC4550412 DOI: 10.1371/journal.pone.0136494] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2015] [Accepted: 07/15/2015] [Indexed: 11/19/2022] Open
Abstract
The development of social behavior is strongly influenced by the serotonin system. Serotonin 2c receptor (5-HT2cR) is particularly interesting in this context considering that pharmacological modulation of 5-HT2cR activity alters social interaction in adult rodents. However, the role of 5-HT2cR in the development of social behavior is unexplored. Here we address this using Htr2c knockout mice, which lack 5-HT2cR. We found that these animals exhibit social behavior deficits as adults but not as juveniles. Moreover, we found that the age of onset of these deficits displays similar timing as the onset of susceptibility to spontaneous death and audiogenic-seizures, consistent with the hypothesis that imbalanced excitation and inhibition (E/I) may contribute to social behavioral deficits. Given that autism spectrum disorder (ASD) features social behavioral deficits and is often co-morbid with epilepsy, and given that 5-HT2cR physically interacts with Pten, we tested whether a second site mutation in the ASD risk gene Pten can modify these phenotypes. The age of spontaneous death is accelerated in mice double mutant for Pten and Htr2c relative to single mutants. We hypothesized that pharmacological antagonism of 5-HT2cR activity in adult animals, which does not cause seizures, might modify social behavioral deficits in Pten haploinsufficient mice. SB 242084, a 5-HT2cR selective antagonist, can reverse the social behavior deficits observed in Pten haploinsufficient mice. Together, these results elucidate a role of 5-HT2cR in the modulation of social behavior and seizure susceptibility in the context of normal development and Pten haploinsufficiency.
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Affiliation(s)
- Julien Séjourné
- Department of Neuroscience, The Scripps Research Institute, 130 Scripps Way, Jupiter, Florida, 33458, United States of America
| | - Danielle Llaneza
- Department of Neuroscience, The Scripps Research Institute, 130 Scripps Way, Jupiter, Florida, 33458, United States of America
| | - Orsolya J. Kuti
- Department of Brain and Cognitive Sciences and Picower Institute for Learning and Memory, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts, 02139, United States of America
| | - Damon T. Page
- Department of Neuroscience, The Scripps Research Institute, 130 Scripps Way, Jupiter, Florida, 33458, United States of America
- * E-mail:
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204
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Pelosi B, Pratelli M, Migliarini S, Pacini G, Pasqualetti M. Generation of a Tph2 Conditional Knockout Mouse Line for Time- and Tissue-Specific Depletion of Brain Serotonin. PLoS One 2015; 10:e0136422. [PMID: 26291320 PMCID: PMC4546246 DOI: 10.1371/journal.pone.0136422] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Accepted: 08/03/2015] [Indexed: 11/29/2022] Open
Abstract
Serotonin has been gaining increasing attention during the last two decades due to the dual function of this monoamine as key regulator during critical developmental events and as neurotransmitter. Importantly, unbalanced serotonergic levels during critical temporal phases might contribute to the onset of neuropsychiatric disorders, such as schizophrenia and autism. Despite increasing evidences from both animal models and human genetic studies have underpinned the importance of serotonin homeostasis maintenance during central nervous system development and adulthood, the precise role of this molecule in time-specific activities is only beginning to be elucidated. Serotonin synthesis is a 2-step process, the first step of which is mediated by the rate-limiting activity of Tph enzymes, belonging to the family of aromatic amino acid hydroxylases and existing in two isoforms, Tph1 and Tph2, responsible for the production of peripheral and brain serotonin, respectively. In the present study, we generated and validated a conditional knockout mouse line, Tph2flox/flox, in which brain serotonin can be effectively ablated with time specificity. We demonstrated that the Cre-mediated excision of the third exon of Tph2 gene results in the production of a Tph2null allele in which we observed the near-complete loss of brain serotonin, as well as the growth defects and perinatal lethality observed in serotonin conventional knockouts. We also revealed that in mice harbouring the Tph2null allele, but not in wild-types, two distinct Tph2 mRNA isoforms are present, namely Tph2Δ3 and Tph2Δ3Δ4, with the latter showing an in-frame deletion of amino acids 84–178 and coding a protein that could potentially retain non-negligible enzymatic activity. As we could not detect Tph1 expression in the raphe, we made the hypothesis that the Tph2Δ3Δ4 isoform can be at the origin of the residual, sub-threshold amount of serotonin detected in the brain of Tph2null/null mice. Finally, we set up a tamoxifen administration protocol that allows an efficient, time-specific inactivation of brain serotonin synthesis. On the whole, we generated a suitable genetic tool to investigate how serotonin depletion impacts on time-specific events during central nervous system development and adulthood life.
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Affiliation(s)
- Barbara Pelosi
- Department of Biology, Unit of Cell and Developmental Biology, University of Pisa, S.S.12 Abetone e Brennero 4, 56127, Pisa, Italy
| | - Marta Pratelli
- Department of Biology, Unit of Cell and Developmental Biology, University of Pisa, S.S.12 Abetone e Brennero 4, 56127, Pisa, Italy
| | - Sara Migliarini
- Department of Biology, Unit of Cell and Developmental Biology, University of Pisa, S.S.12 Abetone e Brennero 4, 56127, Pisa, Italy
| | - Giulia Pacini
- Department of Biology, Unit of Cell and Developmental Biology, University of Pisa, S.S.12 Abetone e Brennero 4, 56127, Pisa, Italy
| | - Massimo Pasqualetti
- Department of Biology, Unit of Cell and Developmental Biology, University of Pisa, S.S.12 Abetone e Brennero 4, 56127, Pisa, Italy
- Center for Neuroscience and Cognitive Systems@UniTn, Istituto Italiano di Tecnologia, Via Bettini 31, 38068, Rovereto (TN), Italy
- * E-mail:
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205
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Schellekens H, De Francesco PN, Kandil D, Theeuwes WF, McCarthy T, van Oeffelen WEPA, Perelló M, Giblin L, Dinan TG, Cryan JF. Ghrelin's Orexigenic Effect Is Modulated via a Serotonin 2C Receptor Interaction. ACS Chem Neurosci 2015; 6:1186-97. [PMID: 25727097 DOI: 10.1021/cn500318q] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Understanding the intricate pathways that modulate appetite and subsequent food intake is of particular importance considering the rise in the incidence of obesity across the globe. The serotonergic system, specifically the 5-HT2C receptor, has been shown to be of critical importance in the regulation of appetite and satiety. The GHS-R1a receptor is another key receptor that is well-known for its role in the homeostatic control of food intake and energy balance. We recently showed compelling evidence for an interaction between the GHS-R1a receptor and the 5-HT2C receptor in an in vitro cell line system heterologously expressing both receptors. Here, we investigated this interaction further. First, we show that the GHS-R1a/5-HT2C dimer-induced attenuation of calcium signaling is not due to coupling to GαS, as no increase in cAMP signaling is observed. Next, flow cytometry fluorescence resonance energy transfer (fcFRET) is used to further demonstrate the direct interaction between the GHS-R1a receptor and 5-HT2C receptor. In addition, we demonstrate colocalized expression of the 5-HT2C and GHS-R1a receptor in cultured primary hypothalamic and hippocampal rat neurons, supporting the biological relevance of a physiological interaction. Furthermore, we demonstrate that when 5-HT2C receptor signaling is blocked ghrelin's orexigenic effect is potentiated in vivo. In contrast, the specific 5-HT2C receptor agonist lorcaserin, recently approved for the treatment of obesity, attenuates ghrelin-induced food intake. This underscores the biological significance of our in vitro findings of 5-HT2C receptor-mediated attenuation of GHS-R1a receptor activity. Together, this study demonstrates, for the first time, that the GHS-R1a/5-HT2C receptor interaction translates into a biologically significant modulation of ghrelin's orexigenic effect. This data highlights the potential development of a combined GHS-R1a and 5-HT2C receptor treatment strategy in weight management.
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Affiliation(s)
| | - Pablo N. De Francesco
- Laboratory
of Neurophysiology, Multidisciplinary Institute of Cell Biology, National Scientific and Technical Research Council, La Plata, Argentina
| | | | | | | | | | - Mario Perelló
- Laboratory
of Neurophysiology, Multidisciplinary Institute of Cell Biology, National Scientific and Technical Research Council, La Plata, Argentina
| | - Linda Giblin
- Teagasc Food Research Centre, Moorepark, Fermoy, Co. Cork, Ireland
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206
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Higgins GA, Fletcher PJ. Therapeutic Potential of 5-HT2C Receptor Agonists for Addictive Disorders. ACS Chem Neurosci 2015; 6:1071-88. [PMID: 25870913 DOI: 10.1021/acschemneuro.5b00025] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The neurotransmitter 5-hydroxytryptamine (5-HT; serotonin) has long been associated with the control of a variety of motivated behaviors, including feeding. Much of the evidence linking 5-HT and feeding behavior was obtained from studies of the effects of the 5-HT releaser (dex)fenfluramine in laboratory animals and humans. Recently, the selective 5-HT2C receptor agonist lorcaserin received FDA approval for the treatment of obesity. This review examines evidence to support the use of selective 5-HT2C receptor agonists as treatments for conditions beyond obesity, including substance abuse (particularly nicotine, psychostimulant, and alcohol dependence), obsessive compulsive, and excessive gambling disorder. Following a brief survey of the early literature supporting a role for 5-HT in modulating food and drug reinforcement, we propose that intrinsic differences between SSRI and serotonin releasers may have underestimated the value of serotonin-based pharmacotherapeutics to treat clinical forms of addictive behavior beyond obesity. We then highlight the critical involvement of the 5-HT2C receptor in mediating the effect of (dex)fenfluramine on feeding and body weight gain and the evidence that 5-HT2C receptor agonists reduce measures of drug reward and impulsivity. A recent report of lorcaserin efficacy in a smoking cessation trial further strengthens the idea that 5-HT2C receptor agonists may have potential as a treatment for addiction. This review was prepared as a contribution to the proceedings of the 11th International Society for Serotonin Research Meeting held in Hermanus, South Africa, July 9-12, 2014.
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Affiliation(s)
- Guy A. Higgins
- InterVivo Solutions Inc., 120 Carlton Street, Toronto, ON M5A
4K2, Canada
- Department of Pharmacology & Toxicology, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Paul J. Fletcher
- Section of Biopsychology
and Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, 250 College Street, Toronto, ON M5T 1R8, Canada
- Departments of Psychiatry & Psychology, University of Toronto, Toronto, ON M5T 1R8, Canada
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207
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Stanquini LA, Resstel LBM, Corrêa FMA, Joca SRL, Scopinho AA. Prelimbic cortex 5-HT1A and 5-HT2C receptors are involved in the hypophagic effects caused by fluoxetine in fasted rats. Pharmacol Biochem Behav 2015; 136:31-8. [PMID: 26143050 DOI: 10.1016/j.pbb.2015.06.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Revised: 06/18/2015] [Accepted: 06/24/2015] [Indexed: 12/20/2022]
Abstract
The regulation of food intake involves a complex interplay between the central nervous system and the activity of organs involved in energy homeostasis. Besides the hypothalamus, recognized as the center of this regulation, other structures are involved, especially limbic regions such as the ventral medial prefrontal cortex (vMPFC). Monoamines, such as serotonin (5-HT), play an important role in appetite regulation. However, the effect in the vMPFC of the selective serotonin reuptake inhibitor (SSRI), fluoxetine, on food intake has not been studied. The aim of the present study was to study the effects on food intake of fed and fasted rats evoked by fluoxetine injection into the prelimbic cortex (PL), a sub-region of the vMPFC, or given systemically, and which 5-HT receptors in the PL are involved in fluoxetine responses. Fluoxetine was injected into the PL or given systemically in male Wistar rats. Independent groups of rats were pretreated with intra-PL antagonists of 5-HT receptors: 5-HT1A (WAY100635), 5-HT2C (SB242084) or 5-HT1B (SB216641). Fluoxetine (0.1; 1; 3; 10nmol/200nL) injected into the PL induced a dose-dependent hypophagic effect in fasted rats. This effect was reversed by prior local treatment with WAY100635 (1; 10nmol) or SB242084 (1; 10nmol), but not with SB216641 (0.2; 2.5; 10nmol). Systemic fluoxetine induced a hypophagic effect, which was blocked by intra-PL 5-HT2C antagonist (10nmol) administration. Our findings suggest that PL 5-HT neurotransmission modulates the central control of food intake and 5-HT1A and 5-HT2C receptors in the PL could be potential targets for the action of fluoxetine.
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Affiliation(s)
- Laura A Stanquini
- Laboratory of Pharmacology, Department of Physics and Chemistry, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Leonardo B M Resstel
- Department of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil; Center for Interdisciplinary Research on Applied Neurosciences (NAPNA), University of São Paulo, SP, Brazil
| | - Fernando M A Corrêa
- Department of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Sâmia R L Joca
- Laboratory of Pharmacology, Department of Physics and Chemistry, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil; Center for Interdisciplinary Research on Applied Neurosciences (NAPNA), University of São Paulo, SP, Brazil
| | - América A Scopinho
- Department of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil.
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208
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Versteeg RI, Serlie MJ, Kalsbeek A, la Fleur SE. Serotonin, a possible intermediate between disturbed circadian rhythms and metabolic disease. Neuroscience 2015; 301:155-67. [PMID: 26047725 DOI: 10.1016/j.neuroscience.2015.05.067] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2015] [Revised: 05/21/2015] [Accepted: 05/27/2015] [Indexed: 01/27/2023]
Abstract
It is evident that eating in misalignment with the biological clock (such as in shift work, eating late at night and skipping breakfast) is associated with increased risk for obesity and diabetes. The biological clock located in the suprachiasmatic nucleus dictates energy balance including feeding behavior and glucose metabolism. Besides eating and sleeping patterns, glucose metabolism also exhibits clear diurnal variations with higher blood glucose concentrations, glucose tolerance and insulin sensitivity prior to waking up. The daily variation in plasma glucose concentrations in rats, is independent of the rhythm in feeding behavior. On the other hand, feeding itself has profound effects on glucose metabolism, but differential effects occur depending on the time of the day. We here review data showing that a disturbed diurnal eating pattern results in alterations in glucose metabolism induced by a disrupted circadian clock. We first describe the role of central serotonin on feeding behavior and glucose metabolism and subsequently describe the effects of central serotonin on the circadian system. We next explore the interaction between the serotonergic system and the circadian clock in conditions of disrupted diurnal rhythms in feeding and how this might be involved in the metabolic dysregulation that occurs with chronodisruption.
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Affiliation(s)
- R I Versteeg
- Department of Endocrinology and Metabolism, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - M J Serlie
- Department of Endocrinology and Metabolism, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - A Kalsbeek
- Department of Endocrinology and Metabolism, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; Hypothalamic Integration Mechanisms, Netherlands Institute for Neuroscience, Amsterdam, The Netherlands
| | - S E la Fleur
- Department of Endocrinology and Metabolism, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
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209
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Fluvoxamine alleviates seizure activity and downregulates hippocampal GAP-43 expression in pentylenetetrazole-kindled mice. Behav Pharmacol 2015; 26:369-82. [DOI: 10.1097/fbp.0000000000000127] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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210
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Burke LK, Heisler LK. 5-hydroxytryptamine medications for the treatment of obesity. J Neuroendocrinol 2015; 27:389-98. [PMID: 25925636 DOI: 10.1111/jne.12287] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Revised: 04/23/2015] [Accepted: 04/23/2015] [Indexed: 12/11/2022]
Abstract
The central 5-hydroxytryptamine (5-HT; serotonin) system represents a fundamental component of the brain's control of energy homeostasis. Medications targeting the 5-HT pathway have been at the forefront of obesity treatment for the past 15 years. Pharmacological agents targeting 5-HT receptors (5-HTR), in combination with genetic models of 5-HTR manipulation, have uncovered a role for specific 5-HTRs in energy balance and reveal the 5-HT2 C R as the principal 5-HTR mediating this homeostatic process. Capitalising on this neurophysiological machinery, 5-HT2 C R agonists improve obesity and glycaemic control in patient populations. The underlying therapeutic mechanism has been probed using model systems and appears to be achieved primarily through 5-HT2 C R modulation of the brain melanocortin circuit via activation of pro-opiomelanocortin neurones signalling at melanocortin4 receptors. Thus, 5-HT2 C R agonists offer a means to improve obesity and type 2 diabetes, which are conditions that now represent global challenges to human health.
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Affiliation(s)
- L K Burke
- Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, UK
- Department of Pharmacology, University of Cambridge, Cambridge, UK
| | - L K Heisler
- Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, UK
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211
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Devlin AM, Panagiotopoulos C. Metabolic side effects and pharmacogenetics of second-generation antipsychotics in children. Pharmacogenomics 2015; 16:981-96. [DOI: 10.2217/pgs.15.55] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Second-generation antipsychotics (SGAs) are increasingly being used to treat children for a range of mental health conditions, for example, anxiety disorder, attention deficit hyperactivity disorder and bipolar disorder. SGA treatment is associated with weight gain and cardiometabolic side effects such as dyslipidemia, insulin resistance and elevated blood pressure, in some, but not all children. This review provides an overview of the potential role of pharmacogenomics in predisposing a child to unhealthy weight gain and cardiometabolic side effects with SGA treatment. Specifically, the review includes a synopsis of the evidence for cardiometabolic side effects in SGA-treated children, illustrating the extent and depth of the problem; summarizes the potential long-term consequences of developing cardiometabolic risk during childhood and highlights genetic variants that may be useful in predicting cardiometabolic side effects in SGA-treated children.
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Affiliation(s)
- Angela M Devlin
- Department of Pediatrics, University of British Columbia, Child & Family Research Institute, 272–950 West 28th Avenue, Vancouver, V5Z 4H4, Canada
| | - Constadina Panagiotopoulos
- Department of Pediatrics, University of British Columbia, Child & Family Research Institute, 272–950 West 28th Avenue, Vancouver, V5Z 4H4, Canada
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212
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Kishimoto R, Tamada K, Liu X, Okubo H, Ise S, Ohta H, Ruf S, Nakatani J, Kohno N, Spitz F, Takumi T. Model mice for 15q11-13 duplication syndrome exhibit late-onset obesity and altered lipid metabolism. Hum Mol Genet 2015; 24:4559-72. [PMID: 26002101 DOI: 10.1093/hmg/ddv187] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Accepted: 05/18/2015] [Indexed: 12/27/2022] Open
Abstract
Copy number variations on human chromosome 15q11-q13 have been implicated in several neurodevelopmental disorders. A paternal loss or duplication of the Prader-Willi syndrome/Angelman syndrome (PWS/AS) region confers a risk of obesity, although the mechanism remains a mystery due to a lack of an animal model that accurately recreates the obesity phenotype. We performed detailed analyses of mice with duplication of PWS/AS locus (6 Mb) generated by chromosome engineering and found that animals with a paternal duplication of this region (patDp/+) show late-onset obesity, high sensitivity for high-fat diet, high levels of blood leptin and insulin without an increase in food intake. We show that prior to becoming obese, young patDp/+ mice already had enlarged white adipocytes. Transcriptome analysis of adipose tissue revealed an up-regulation of Secreted frizzled-related protein 5 (Sfrp5), known to promote adipogenesis. We additionally generated a new mouse model of paternal duplication focusing on a 3 Mb region (3 Mb patDp/+) within the PWS/AS locus. These mice recapitulate the obese phenotypes including expansion of visceral adipose tissue. Our results suggest paternally expressed genes in PWS/AS locus play a significant role for the obesity and identify new potential targets for future research and treatment of obesity.
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Affiliation(s)
- Rui Kishimoto
- RIKEN Brain Science Institute, Wako, Saitama 351-0198, Japan, Graduate School of Biomedical Sciences, Hiroshima University, Minami, Hiroshima 734-8553, Japan
| | - Kota Tamada
- RIKEN Brain Science Institute, Wako, Saitama 351-0198, Japan, Graduate School of Biomedical Sciences, Hiroshima University, Minami, Hiroshima 734-8553, Japan
| | - Xiaoxi Liu
- RIKEN Brain Science Institute, Wako, Saitama 351-0198, Japan
| | - Hiroko Okubo
- RIKEN Brain Science Institute, Wako, Saitama 351-0198, Japan
| | - Satoko Ise
- Banyu Tsukuba Research Institute, Tsukuba, Ibaraki 300-2611, Japan
| | - Hisashi Ohta
- Banyu Tsukuba Research Institute, Tsukuba, Ibaraki 300-2611, Japan
| | - Sandra Ruf
- Developmental Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Jin Nakatani
- Molecular Neuroscience Research Center, Shiga University of Medical Science, Ohtsu, Shiga 520-2192, Japan and
| | - Nobuoki Kohno
- Graduate School of Biomedical Sciences, Hiroshima University, Minami, Hiroshima 734-8553, Japan
| | - François Spitz
- Developmental Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Toru Takumi
- RIKEN Brain Science Institute, Wako, Saitama 351-0198, Japan, Graduate School of Biomedical Sciences, Hiroshima University, Minami, Hiroshima 734-8553, Japan, JST, CREST, Tokyo, Japan
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213
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Yan C, Yang Y, Saito K, Xu P, Wang C, Hinton AO, Yan X, Wu Q, Tong Q, Elmquist JK, Fukuda M, Xu Y. Meta-chlorophenylpiperazine enhances leptin sensitivity in diet-induced obese mice. Br J Pharmacol 2015; 172:3510-21. [PMID: 25817043 DOI: 10.1111/bph.13141] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Revised: 03/04/2015] [Accepted: 03/22/2015] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND AND PURPOSE Most forms of human obesity are characterized by impaired leptin sensitivity and, therefore, the effectiveness of anti-obesity leptin therapy in these leptin-resistant obese patients is marginal. Hence, the development of strategies to increase leptin sensitivity is of high priority in the field of obesity research. EXPERIMENTAL APPROACH We first examined the effects of co-administration of leptin and meta-chlorophenylpiperazine (mCPP), an agonist of 5-HT2C and 5-HT1B receptors, on energy balance in leptin-resistant diet-induced obese (DIO) mice. We further assessed leptin-induced phosphorylation of the STAT-3 (pSTAT3) in various brain regions of DIO mice pretreated with mCPP or in mice genetically lacking 5-HT2C receptors. RESULTS Co-administration of mCPP with leptin had an additive effect on reducing body weight in DIO mice. Furthermore, mCPP pretreatment in DIO mice enhanced leptin-induced pSTAT3 in the arcuate nucleus, the ventromedial hypothalamic nucleus, and the ventral premammillary nucleus. Finally, deletion of 5-HT2C receptors significantly blunted leptin-induced pSTAT3 in these same hypothalamic regions. CONCLUSIONS AND IMPLICATIONS Our study provides evidence that drugs, which activate 5-HT2C receptors, could function as leptin sensitizers and be used in combination with leptin to provide additional weight loss in DIO.
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Affiliation(s)
- Chunling Yan
- Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA.,Medical College, Qingdao University, Qingdao, China
| | - Yongjie Yang
- Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
| | - Kenji Saito
- Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
| | - Pingwen Xu
- Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
| | - Chunmei Wang
- Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
| | - Antentor Othrell Hinton
- Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
| | - Xiaofeng Yan
- Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
| | - Qi Wu
- Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
| | - Qingchun Tong
- Brown Foundation Institute of Molecular Medicine, University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Joel K Elmquist
- Division of Hypothalamic Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Makoto Fukuda
- Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
| | - Yong Xu
- Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA.,Department of Molecular and Cellular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX, USA
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McGlashon JM, Gorecki MC, Kozlowski AE, Thirnbeck CK, Markan KR, Leslie KL, Kotas ME, Potthoff MJ, Richerson GB, Gillum MP. Central serotonergic neurons activate and recruit thermogenic brown and beige fat and regulate glucose and lipid homeostasis. Cell Metab 2015; 21:692-705. [PMID: 25955206 PMCID: PMC4565052 DOI: 10.1016/j.cmet.2015.04.008] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Revised: 02/10/2015] [Accepted: 04/03/2015] [Indexed: 01/06/2023]
Abstract
Thermogenic brown and beige adipocytes convert chemical energy to heat by metabolizing glucose and lipids. Serotonin (5-HT) neurons in the CNS are essential for thermoregulation and accordingly may control metabolic activity of thermogenic fat. To test this, we generated mice in which the human diphtheria toxin receptor (DTR) was selectively expressed in central 5-HT neurons. Treatment with diphtheria toxin (DT) eliminated 5-HT neurons and caused loss of thermoregulation, brown adipose tissue (BAT) steatosis, and a >50% decrease in uncoupling protein 1 (Ucp1) expression in BAT and inguinal white adipose tissue (WAT). In parallel, blood glucose increased 3.5-fold, free fatty acids 13.4-fold, and triglycerides 6.5-fold. Similar BAT and beige fat defects occurred in Lmx1b(f/f)ePet1(Cre) mice in which 5-HT neurons fail to develop in utero. We conclude 5-HT neurons play a major role in regulating glucose and lipid homeostasis, in part through recruitment and metabolic activation of brown and beige adipocytes.
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Affiliation(s)
- Jacob M McGlashon
- Department of Neurology, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA; Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, 2200 Copenhagen, Denmark; Institute of Biomedical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Michelle C Gorecki
- Department of Neurology, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA; Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, 2200 Copenhagen, Denmark; Institute of Biomedical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Amanda E Kozlowski
- Department of Neurology, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - Caitlin K Thirnbeck
- Department of Neurology, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - Kathleen R Markan
- Department of Pharmacology, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - Kirstie L Leslie
- Department of Neurology, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - Maya E Kotas
- Department of Medicine, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA
| | - Matthew J Potthoff
- Department of Pharmacology, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - George B Richerson
- Department of Neurology, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA; Department of Molecular Physiology & Biophysics, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA; Veterans Affairs Medical Center, Iowa City, IA 52242, USA
| | - Matthew P Gillum
- Department of Neurology, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA; Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, 2200 Copenhagen, Denmark; Institute of Biomedical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark.
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215
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Role of 5-HT2 receptors in diabetes: Swertiamarin seco-iridoid glycoside might be a possible 5-HT2 receptor modulator. Physiol Behav 2015; 144:66-72. [DOI: 10.1016/j.physbeh.2015.02.036] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Revised: 01/16/2015] [Accepted: 02/16/2015] [Indexed: 01/23/2023]
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216
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Tripathi PP, Bozzi Y. The role of dopaminergic and serotonergic systems in neurodevelopmental disorders: a focus on epilepsy and seizure susceptibility. ACTA ACUST UNITED AC 2015; 5:97-102. [PMID: 26191504 PMCID: PMC4492191 DOI: 10.15171/bi.2015.07] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Revised: 01/22/2015] [Accepted: 02/14/2015] [Indexed: 01/16/2023]
Abstract
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Introduction: The embryonic development of the vertebrate Central Nervous System (CNS) requires the induction of transcription factors regulating the expression of specific subsets of genes in restricted CNS regions. Among these transcription factors, homeobox-containing proteins play a crucial role, and altered expression of these factors can impact the embryonic as well as adult CNS functions. Importantly, the homeobox-containing genes Otx2, Engrailed-1 (En1), and Engrailed-2 (En2) have been described to crucially regulate differentiation of dopaminergic and serotonergic neurons during vertebrate CNS development. Dopaminergic and serotonergic neurons, located in midbrain and hindbrain regions respectively, diffusely innervate several forebrain areas including limbic system, contributing in regulating several physiological functions. Understanding the embryonic development of these neuronal populations is crucial to elucidate their physiological function including brain excitability in the adult brain. New evidence is emerging about the impact of an altered embryonic development of dopamine and serotonin neurons onto seizure susceptibility in the adult life.
Methods: In this mini-review, we summarized our kainic acid (KA) induced seizure susceptibility in adult mutant mouse lines with targeted manipulation of Otx2, En1, and En2 genes.
Results: Our results demonstrated that altered development of dopamine (DA) neurons does not interfere with KA seizure susceptibility, while increased serotonin (5-hydroxytryptamine, 5-HT) hyperinnervation leads to resistance to KA-induced seizure.
Conclusion: We propose that developmental alterations of serotonergic but not dopaminergic circuits play a crucial role in controlling seizure susceptibility in the adult life
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Affiliation(s)
- Prem Prakash Tripathi
- Laboratory of Molecular Neuropathology, Center for Integrative Biology (CIBIO), University of Trento, Trento, Italy
| | - Yuri Bozzi
- Laboratory of Molecular Neuropathology, Center for Integrative Biology (CIBIO), University of Trento, Trento, Italy
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217
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Abstract
PURPOSE OF REVIEW Human and experimental research has identified cardioautonomic and respiratory dysfunction as a frequent accompaniment in human and animal model events of sudden unexpected death in epilepsy (SUDEP). This review aims to provide an overview of the scientific evidence behind the currently accepted risk factors and working hypotheses regarding SUDEP pathophysiology. RECENT FINDINGS Epidemiological analysis of public health burden of SUDEP has shown that it rates second only to stroke in the years of potential life lost. Clinical and experimental studies uncovered the dynamic cardiorespiratory dysfunction interictally and imminently to SUDEP, and model systems have facilitated discoveries in SUDEP mechanistic understanding and application of pilot therapeutic interventions. Pilot molecular profiling of human SUDEP has uncovered complex genomic structure in the candidate gene network. SUMMARY Extensive clinical and experimental work has established a rationale for the conceptual thinking about SUDEP mechanisms. The application of the global molecular profiling will be invaluable in unraveling the individually unique genomic complexities and interactions that underlie the physiological signature of each patient. At the same time, sophisticated model systems will be critical in the iterative translation of human genetics, physiology, pharmacological interventions, and in testing preventive interventions.
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Affiliation(s)
- Alica M Goldman
- Department of Neurology, Baylor College of Medicine, Houston, Texas, USA
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218
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Guiard BP, Di Giovanni G. Central serotonin-2A (5-HT2A) receptor dysfunction in depression and epilepsy: the missing link? Front Pharmacol 2015; 6:46. [PMID: 25852551 PMCID: PMC4362472 DOI: 10.3389/fphar.2015.00046] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2015] [Accepted: 02/24/2015] [Indexed: 11/17/2022] Open
Abstract
5-Hydroxytryptamine 2A receptors (5-HT2A-Rs) are G-protein coupled receptors. In agreement with their location in the brain, they have been implicated not only in various central physiological functions including memory, sleep, nociception, eating and reward behaviors, but also in many neuropsychiatric disorders. Interestingly, a bidirectional link between depression and epilepsy is suspected since patients with depression and especially suicide attempters have an increased seizure risk, while a significant percentage of epileptic patients suffer from depression. Such epidemiological data led us to hypothesize that both pathologies may share common anatomical and neurobiological alteration of the 5-HT2A signaling. After a brief presentation of the pharmacological properties of the 5-HT2A-Rs, this review illustrates how these receptors may directly or indirectly control neuronal excitability in most networks involved in depression and epilepsy through interactions with the monoaminergic, GABAergic and glutamatergic neurotransmissions. It also synthetizes the preclinical and clinical evidence demonstrating the role of these receptors in antidepressant and antiepileptic responses.
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Affiliation(s)
- Bruno P Guiard
- CNRS, Centre de Recherches sur la Cognition Animale, UMR 5169, Toulouse France ; CNRS, Centre de Recherches sur la Cognition Animale Université de Toulouse 3, UMR 5169, Toulouse, France ; INSERM U1178 Team ≪Depression and Antidepressants≫ Faculté de Pharmacie Paris Sud, Châtenay-Malabry, France
| | - Giuseppe Di Giovanni
- Neurophysiology Unit, Laboratory for the Study of Neurological Disorders, Department of Physiology and Biochemistry, University of Malta, Msida Malta ; School of Biosciences, University of Cardiff, Cardiff UK
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219
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Sachs GS, Greenberg WM, Starace A, Lu K, Ruth A, Laszlovszky I, Németh G, Durgam S. Cariprazine in the treatment of acute mania in bipolar I disorder: a double-blind, placebo-controlled, phase III trial. J Affect Disord 2015; 174:296-302. [PMID: 25532076 DOI: 10.1016/j.jad.2014.11.018] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Accepted: 11/13/2014] [Indexed: 01/09/2023]
Abstract
BACKGROUND This Phase III, randomized, double-blind, placebo-controlled study investigated the efficacy and tolerability of flexibly-dosed cariprazine in patients with acute manic or mixed episodes associated with bipolar I disorder. METHODS Patients were randomized to 3 weeks of double-blind treatment with cariprazine 3-12mg/day (n=158) or placebo (n=154). The primary efficacy parameter was change from baseline to Week 3 in Young Mania Rating Scale (YMRS) total score. The secondary efficacy parameter was change from baseline to Week 3 in Clinical Global Impressions-Severity (CGI-S) score. RESULTS Mean change from baseline to Week 3 in YMRS total score was significantly greater for patients receiving cariprazine 3-12mg/day versus placebo (P=0.0004). Significant differences between groups in YMRS total score mean change were observed by Day 4 (first postbaseline assessment) and maintained throughout double-blind treatment (all assessments, P<0.01). Cariprazine also demonstrated statistically significant superiority over placebo on YMRS response (≥50% improvement: cariprazine, 58.9%; placebo, 44.1%; P=0.0097) and remission (YMRS total score≤12: cariprazine, 51.9%; placebo, 34.9%; P=0.0025) and mean change in CGI-S (P=0.0027) score and Positive and Negative Syndrome Scale (PANSS) (P=0.0035) total score. The most common cariprazine-related (≥10% and twice placebo) treatment emergent adverse events (TEAEs) were akathisia, extrapyramidal disorder, tremor, dyspepsia, and vomiting. Mean change from baseline in metabolic parameters were generally small and similar between groups. LIMITATIONS Lack of active comparator arm; short duration of study. CONCLUSION In this study, cariprazine 3-12mg/day was effective and generally well tolerated in the treatment of manic and mixed episodes associated with bipolar I disorder.
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Affiliation(s)
- Gary S Sachs
- Massachusetts General Hospital, 15 Parkman Street, Boston, MA 02114-3117, USA.
| | | | | | - Kaifeng Lu
- Forest Research Institute, Jersey City, NJ, USA
| | - Adam Ruth
- Prescott Medical Communications Group, Chicago, IL, USA
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220
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Abstract
Eating disorders (EDs) are serious psychiatric conditions influenced by biological, psychological, and sociocultural factors. A better understanding of the genetics of these complex traits and the development of more sophisticated molecular biology tools have advanced our understanding of the etiology of EDs. The aim of this review is to critically evaluate the literature on the genetic research conducted on three major EDs: anorexia nervosa (AN), bulimia nervosa (BN), and binge eating disorder (BED). We will first review the diagnostic criteria, clinical features, prevalence, and prognosis of AN, BN, and BED, followed by a review of family, twin, and adoption studies. We then review the history of genetic studies of EDs covering linkage analysis, candidate gene association studies, genome-wide association studies, and the study of rare variants in EDs. Our review also incorporates a translational perspective by covering animal models of ED-related phenotypes. Finally, we review the nascent field of epigenetics of EDs and a look forward to future directions for ED genetic research.
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Affiliation(s)
- Zeynep Yilmaz
- Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - J Andrew Hardaway
- Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Cynthia M Bulik
- Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA; Department of Nutrition, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA; Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
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221
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Afarideh M, Behdadnia A, Noshad S, Mirmiranpour H, Mousavizadeh M, Khajeh E, Rad MV, Mazaheri T, Nakhjavani M, Esteghamati A. ASSOCIATION OF PERIPHERAL 5-HYDROXYINDOLE-3-ACETIC ACID, A SEROTONIN DERIVATIVE, WITH METABOLIC SYNDROME AND LOW-GRADE INFLAMMATION. Endocr Pract 2015; 21:711-8. [PMID: 25716631 DOI: 10.4158/ep14442.or] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
OBJECTIVE The constellation of metabolic abnormalities seen in metabolic syndrome (MetS) has been linked to atherosclerosis and adverse cardiovascular outcomes due to heightened inflammation. Accumulating evidence suggests that peripheral 5-hydroxyindole-3-acetic acid (5-HIAA), the derivative end-product of serotonin (5-HT), might be involved in the pathogenesis of obesity, and abnormal lipid and glucose metabolism. We examined the association between serum 5-HIAA concentrations and MetS and also highly sensitive C-reactive protein (hsCRP). METHODS We assessed 180 healthy adults (110 males and 70 females) in a cross-sectional setting. Anthropometric indices and blood pressure were measured, as were laboratory parameters including fasting 5-HIAA concentrations. The associations between 5-HIAA and individual components of MetS, as well as MetS as a single entity, were investigated with bivariate correlation and logistic regression analyses. RESULTS Eighty-nine individuals (49.4%) were diagnosed with MetS. Significant correlations were found between 5-HIAA concentrations and age (r = 0.184), waist circumference (r = 0.415), high-density lipoprotein (HDL) cholesterol (r = -0.148), systolic blood pressure (r = 0.374), diastolic blood pressure (r = 0.355), homeostasis model assessment of insulin resistance (r = 0.201), and hsCRP (r = 0.453) were found (P<.05 in all tests). In logistic regression, 5-HIAA was significantly associated with 4 MetS components including central obesity, raised triglycerides, raised blood pressure, and raised fasting plasma glucose (FPG) (P<.05). Moreover, 5-HIAA was a predictor of MetS as a single entity, and the relationship persisted after adjusting for hsCRP (odds ratio [OR] = 4.41, 95% confidence interval [CI]: 2.58-7.67, P<.001). CONCLUSION Elevated concentrations of 5-HIAA are seen in individuals with MetS. Increased 5-HIAA is also associated with hsCRP, a marker of chronic low-grade inflammation underlying MetS.
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Lopez‐Esparza S, Berumen LC, Padilla K, Miledi R, García‐Alcocer G. Expression of hippocampal serotonin receptors 5‐HT
2C
and 5‐HT
5A
in a rat model of diet‐induced obesity supplemented with tryptophan. Int J Dev Neurosci 2015; 42:80-5. [DOI: 10.1016/j.ijdevneu.2015.02.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Revised: 01/31/2015] [Accepted: 02/20/2015] [Indexed: 10/25/2022] Open
Affiliation(s)
- Sarahi Lopez‐Esparza
- Facultad de QuímicaUniversidad Autónoma de Querétaro, Centro UniversitarioQuerétaro76010Mexico
| | - Laura C. Berumen
- Facultad de QuímicaUniversidad Autónoma de Querétaro, Centro UniversitarioQuerétaro76010Mexico
| | - Karla Padilla
- Facultad de QuímicaUniversidad Autónoma de Querétaro, Centro UniversitarioQuerétaro76010Mexico
| | - Ricardo Miledi
- Instituto de NeurobiologíaUniversidad Nacional Autónoma de MéxicoCampus JuriquillaQuerétaro76230Mexico
- Department of Neurobiology and BehaviorUniversity of CaliforniaIrvineCA92697‐4550USA
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Investigating interactions between phentermine, dexfenfluramine, and 5-HT2C agonists, on food intake in the rat. Psychopharmacology (Berl) 2015; 232:1973-82. [PMID: 25524140 PMCID: PMC4425807 DOI: 10.1007/s00213-014-3829-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Accepted: 11/20/2014] [Indexed: 10/26/2022]
Abstract
RATIONALE Synergistic or supra-additive interactions between the anorectics (dex)fenfluramine and phentermine have been reported previously in the rat and in the clinic. Studies with 5-HT2C antagonists and 5-HT2C knockouts have demonstrated dexfenfluramine hypophagia in the rodent to be mediated by actions at the 5-HT2C receptor. Given the recent FDA approval of the selective 5-HT2C agonist lorcaserin (BELVIQ®) for weight management, we investigated the interaction between phentermine and 5-HT2C agonists on food intake. OBJECTIVES This study aims to confirm dexfenfluramine-phentermine (dex-phen) synergy in a rat food intake assay, to extend these findings to other 5-HT2C agonists, and to determine whether pharmacokinetic interactions could explain synergistic findings with particular drug combinations. METHODS Isobolographic analyses were performed in which phentermine was paired with either dexfenfluramine, the 5-HT2C agonist AR630, or the 5-HT2C agonist lorcaserin, and inhibition of food intake measured in the rat. Subsequent studies assessed these same phentermine-drug pair combinations spanning both the full effect range and a range of fixed ratio drug combinations. Satellite groups received single doses of each drug either alone or in combination with phentermine, and free brain concentrations were measured. RESULTS Dex-phen synergy was confirmed in the rat and extended to the 5-HT2C agonist AR630. In contrast, although some synergistic interactions between lorcaserin and phentermine were observed, these combinations were largely additive. Synergistic interactions between phentermine and dexfenfluramine or AR630 were accompanied by combination-induced increases in brain levels of phentermine. CONCLUSIONS Dex-phen synergy in the rat is caused by a pharmacokinetic interaction, resulting in increased central concentrations of phentermine.
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224
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Voigt JP, Fink H. Serotonin controlling feeding and satiety. Behav Brain Res 2015; 277:14-31. [DOI: 10.1016/j.bbr.2014.08.065] [Citation(s) in RCA: 192] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Revised: 08/14/2014] [Accepted: 08/19/2014] [Indexed: 02/06/2023]
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Shidore M, Machhi J, Murumkar P, Barmade M, Thanki J, Yadav MR. 3-Substituted 1-methyl-3-benzazepin-2-ones as 5-HT2C receptor agonists. RSC Adv 2015. [DOI: 10.1039/c5ra17718a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
In search of potent and selective 5-HT2C receptor agonists, a series of novel 3-substituted 1-methyl-3-benzazepin-2-ones and 8-chloro-1-methyl-3-benzazepin-2-ones have been synthesized and evaluated for their 5-HT2C receptor agonistic potential.
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Affiliation(s)
- Mahesh Shidore
- Pharmacy Department
- Faculty of Technology & Engineering, Kalabhavan
- The M. S. University of Baroda
- Vadodara-390 001
- India
| | - Jatin Machhi
- Pharmacy Department
- Faculty of Technology & Engineering, Kalabhavan
- The M. S. University of Baroda
- Vadodara-390 001
- India
| | - Prashant Murumkar
- Pharmacy Department
- Faculty of Technology & Engineering, Kalabhavan
- The M. S. University of Baroda
- Vadodara-390 001
- India
| | - Mahesh Barmade
- Pharmacy Department
- Faculty of Technology & Engineering, Kalabhavan
- The M. S. University of Baroda
- Vadodara-390 001
- India
| | - Jigar Thanki
- Pharmacy Department
- Faculty of Technology & Engineering, Kalabhavan
- The M. S. University of Baroda
- Vadodara-390 001
- India
| | - Mange Ram Yadav
- Pharmacy Department
- Faculty of Technology & Engineering, Kalabhavan
- The M. S. University of Baroda
- Vadodara-390 001
- India
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He X, Robertson N, Jazayeri A, Gasperina AG, Schertler G, Li X. Large scale expression and purification of the rat 5-HT2c receptor. Protein Expr Purif 2014; 106:1-9. [PMID: 25448824 DOI: 10.1016/j.pep.2014.10.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Revised: 10/16/2014] [Accepted: 10/21/2014] [Indexed: 10/24/2022]
Abstract
5-HT2c G-protein coupled receptors located in the central nervous system bind the endogenous neurotransmitters serotonin and couple to G protein to mediate excitatory neurotransmission, which inhibits dopamine and norepinephrine release in the brain. Thus, 5-HT2c receptors play important roles in cognitive function and are potent drug targets. Structural information is needed to elucidate the molecular mechanism of ligand-binding and receptor-activation of the 5-HT2c receptor. Lacking of an efficient expression system that produces sufficient amounts of active and homogenous receptors hinders progress in the functional and structural characterization of the 5-HT2c receptor. We present here a protocol which can be used easily to obtain milligram amount of purified rat 5-HT2c receptors. We established this protocol by protein engineering and optimization of expression and purification based on radioligand-binding assay. The purified and well-characterized rat 5-HT2c receptors are active, stable, homogenous, and ready for 2-dimensional and 3-dimensional crystallization experiments.
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Affiliation(s)
- Xiaoqin He
- Laboratory of Biomolecular Research, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland
| | - Nathan Robertson
- Heptares Therapeutics, BioPark, Broadwater Road, Welwyn Garden City, Hertfordshire AL7 3AX, UK
| | - Ali Jazayeri
- Heptares Therapeutics, BioPark, Broadwater Road, Welwyn Garden City, Hertfordshire AL7 3AX, UK
| | | | - Gebhard Schertler
- Laboratory of Biomolecular Research, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland
| | - Xiaodan Li
- Laboratory of Biomolecular Research, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland.
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227
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Gehlert DR, Shaw J. 5-Hydroxytryptamine 1A (5HT1A) receptors mediate increases in plasma glucose independent of corticosterone. Eur J Pharmacol 2014; 745:91-7. [DOI: 10.1016/j.ejphar.2014.10.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Revised: 10/06/2014] [Accepted: 10/08/2014] [Indexed: 11/29/2022]
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228
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Tohda M. Serotonin 2C receptor as a superhero: diversities and talents in the RNA universe for editing, variant, small RNA and other expected functional RNAs. J Pharmacol Sci 2014; 126:321-8. [PMID: 25427431 DOI: 10.1254/jphs.14r06cr] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
Abstract
The serotonin 2C receptor subtype (5-HT2C) has a unique profession and continues to provide exciting and critical new information. The 5-HT2C is modulated at the RNA level by several mechanisms, including editing, short variant generation, and small RNAs. Recently, these phenomena, which had been demonstrated individually, were shown to be associated with each other. At present, many reports provide information about the influence of RNA regulation on receptor protein activities and expression, which was thought to be the final functional product. However, complicated behavior at the RNA stage allows us to imagine that the RNA itself has functional roles in the RNA universe. The 5-HT2C RNA may play several roles. This review will outline previous 5-HT2C studies and prospects for future studies.
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Affiliation(s)
- Michihisa Tohda
- Division of Medicinal Pharmacology, Institute of Natural Medicine, and Wakanyaku Theory-Based Integrated Pharmacology, Graduate School of Innovative Life Science, University of Toyama, Japan
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229
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Neocortical serotonin2A receptor binding predicts quetiapine associated weight gain in antipsychotic-naive first-episode schizophrenia patients. Int J Neuropsychopharmacol 2014; 17:1729-36. [PMID: 24830305 DOI: 10.1017/s1461145714000777] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Antipsychotic-induced weight gain is of major clinical importance since it is associated with severe metabolic complications and increased mortality. The serotonin2A receptor system has been suggested to be implicated in weight gain and obesity. However, no previous in vivo imaging data have related serotonin2A receptor binding to weight gain before and after antipsychotic monotherapy. Fifteen antipsychotic-naive first-episode schizophrenia patients were included and investigated before and after six months of quetiapine treatment. We examined the relationship between serotonin2A receptor binding as measured with positron emission tomography (PET) and [18F]altanserin and change in body mass index (BMI). Quetiapine was chosen because it is characterized by a moderately high affinity for the serotonin2A receptor and a fast dissociation rate from the dopamine D2 receptor. At baseline the mean BMI was 24.2 kg/m2, range 18-36 kg/m2. After six months of quetiapine treatment (mean dose: 383 mg/day) the BMI had, on average, increased by 6.7%, corresponding to an average weight gain of 5.0 kg. We found a significant positive correlation both between neocortical serotonin2A receptor binding prior to treatment and subsequent increase in BMI (rho=0.59, p=0.022). At follow-up, the serotonin2A receptor occupancy was positively correlated with BMI increase (rho=0.54, p=0.038). To our knowledge, these are the first in vivo receptor imaging data in initially antipsychotic-naive first-episode schizophrenia patients to show that the cerebral serotonin2A receptor is associated with antipsychotic-induced weight gain.
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230
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Schellekens H, Nongonierma AB, Clarke G, van Oeffelen WE, FitzGerald RJ, Dinan TG, Cryan JF. Milk protein-derived peptides induce 5-HT2C-mediated satiety in vivo. Int Dairy J 2014. [DOI: 10.1016/j.idairyj.2014.04.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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231
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Burke MV, Nocjar C, Sonneborn AJ, McCreary AC, Pehek EA. Striatal serotonin 2C receptors decrease nigrostriatal dopamine release by increasing GABA-A receptor tone in the substantia nigra. J Neurochem 2014; 131:432-43. [PMID: 25073477 DOI: 10.1111/jnc.12842] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Revised: 07/24/2014] [Accepted: 07/28/2014] [Indexed: 11/29/2022]
Abstract
Drugs acting at the serotonin-2C (5-HT2C) receptor subtype have shown promise as therapeutics in multiple syndromes including obesity, depression, and Parkinson's disease. While it is established that 5-HT2C receptor stimulation inhibits DA release, the neural circuits and the localization of the relevant 5-HT2C receptors remain unknown. This study used dual-probe in vivo microdialysis to investigate the relative contributions of 5-HT2C receptors localized in the rat substantia nigra (SN) and caudate-putamen (CP) in the control of nigrostriatal DA release. Systemic administration (3.0 mg/kg) of the 5-HT2C receptor selective agonist Ro 60-0175 [(αS)-6-Chloro-5-fluoro-α-methyl-1H-indole-1-ethanamine fumarate] decreased, whereas intrastriatal infusions of the selective 5-HT2C antagonist SB 242084 [6-Chloro-2,3-dihydro-5-methyl-N-[6-[(2-methyl-3-pyridinyl)oxy]-3-pyridinyl]-1H-indole-1-carboxyamide; 1.0 μM] increased, basal DA in the CP. Depending on the site within the SN pars reticulata (SNpr), infusions of SB 242084 had more modest but significant effects. Moreover, infusions of the GABA-A receptor agonist muscimol (10 μM) into the SNpr completely reversed the increases in striatal DA release produced by intrastriatal infusions of SB 242084. These findings suggest a role for 5-HT2C receptors regulating striatal DA release that is highly localized. 5-HT2C receptors localized in the striatum may represent a primary site of action that is mediated by the actions on GABAergic activity in the SN. Dopamine (DA) neurons in the substantia nigra pars compacta (SNpc) project to the caudate-putamen (CP; striatum). This circuitry is implicated in numerous pathologies including Parkinson's disease. Using in vivo microdialysis, we demonstrated that blockade of serotonin (5-HT) 2C receptors in the CP increased nigrostriatal DA release. Infusions of a GABA-A agonist into the substantia nigra pars reticulata (SNpr) blocked this increase. This work indicates that striatal serotonin 2C receptors regulate GABAergic tone in the SNpr, which in turn regulates nigrostriatal DA release.
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Affiliation(s)
- Mary V Burke
- Research, Louis Stokes Cleveland Department of Veterans Affairs, Cleveland, Ohio, USA; Interdepartmental Neuroscience Program, Yale University, New Haven, Connecticut, USA
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232
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Abstract
Obesity is a major health problem worldwide. Although diet and physical activity are crucial in the management of obesity, the long-term success rate is low. Therefore antiobesity drugs are of great interest, especially when lifestyle modification has failed. As obesity is not an immediate life-threatening disease, these drugs are required to be safe. Antiobesity drugs that have been developed so far have limited efficacies and considerable adverse effects affecting tolerability and safety. Therefore, most antiobesity drugs have been withdrawn. Fenfluramine and dexfenfluramine were withdrawn because of the potential damage to heart valves. Sibutramine was associated with an increase in major adverse cardiovascular events in the Sibutramine Cardiovascular Outcomes (SCOUT) trial and it was withdrawn from the market in 2010. Rimonabant was withdrawn because of significant psychiatric adverse effects. Orlistat was approved in Europe and the United States for long-term treatment of obesity, but many patients cannot tolerate its gastrointestinal side effects. Phentermine and diethylpropion can only be used for less than 12 weeks because the long-term safety of these drugs is unknown. Ephedrine and caffeine are natural substances but the effects on weight reduction are modest. As a result there is a huge unmet need for effective and safe antiobesity drugs. Recently lorcaserin and topiramate plus phentermine have been approved for the treatment of obesity but long-term safety data are lacking.
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Affiliation(s)
- Bernard Man Yung Cheung
- Division of Clinical Pharmacology and Therapeutics, Department of Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
| | - Tommy Tsang Cheung
- Division of Clinical Pharmacology and Therapeutics, Department of Medicine, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong
| | - Nithushi Rajitha Samaranayake
- Division of Clinical Pharmacology and Therapeutics, Department of Medicine, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong
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233
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Lian J, Huang XF, Pai N, Deng C. Preventing olanzapine-induced weight gain using betahistine: a study in a rat model with chronic olanzapine treatment. PLoS One 2014; 9:e104160. [PMID: 25084453 PMCID: PMC4118967 DOI: 10.1371/journal.pone.0104160] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Accepted: 07/11/2014] [Indexed: 12/19/2022] Open
Abstract
Olanzapine is the one of first line antipsychotic drug for schizophrenia and other serious mental illness. However, it is associated with troublesome metabolic side-effects, particularly body weight gain and obesity. The antagonistic affinity to histamine H1 receptors (H1R) of antipsychotic drugs has been identified as one of the main contributors to weight gain/obesity side-effects. Our previous study showed that a short term (2 weeks) combination treatment of betahistine (an H1R agonist and H3R antagonist) and olanzapine (O+B) reduced (−45%) body weight gain induced by olanzapine in drug-naïve rats. A key issue is that clinical patients suffering with schizophrenia, bipolar disease and other mental disorders often face chronic, even life-time, antipsychotic treatment, in which they have often had previous antipsychotic exposure. Therefore, we investigated the effects of chronic O+B co-treatment in controlling body weight in female rats with chronic and repeated exposure of olanzapine. The results showed that co-administration of olanzapine (3 mg/kg, t.i.d.) and betahistine (9.6 mg/kg, t.i.d.) significantly reduced (−51.4%) weight gain induced by olanzapine. Co-treatment of O+B also led to a decrease in feeding efficiency, liver and fat mass. Consistently, the olanzapine-only treatment increased hypothalamic H1R protein levels, as well as hypothalamic pAMPKα, AMPKα and NPY protein levels, while reducing the hypothalamic POMC, and UCP1 and PGC-1α protein levels in brown adipose tissue (BAT). The olanzapine induced changes in hypothalamic H1R, pAMPKα, BAT UCP1 and PGC-1α could be reversed by co-treatment of O+B. These results supported further clinical trials to test the effectiveness of co-treatment of O+B for controlling weight gain/obesity side-effects in schizophrenia with chronic antipsychotic treatment.
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Affiliation(s)
- Jiamei Lian
- Antipsychotic Research Laboratory, Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, Australia
- Centre for Translational Neuroscience, School of Medicine, and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, Australia
| | - Xu-Feng Huang
- Centre for Translational Neuroscience, School of Medicine, and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, Australia
- Schizophrenia Research Institute, Sydney, NSW, Australia
| | - Nagesh Pai
- Centre for Translational Neuroscience, School of Medicine, and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, Australia
| | - Chao Deng
- Antipsychotic Research Laboratory, Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, Australia
- Centre for Translational Neuroscience, School of Medicine, and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, Australia
- Schizophrenia Research Institute, Sydney, NSW, Australia
- * E-mail:
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234
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Phi-van L, Holtz M, Kjaer JB, van Phi VD, Zimmermann K. A functional variant in the 5'-flanking region of the chicken serotonin transporter gene is associated with increased body weight and locomotor activity. J Neurochem 2014; 131:12-20. [PMID: 24947945 DOI: 10.1111/jnc.12799] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Revised: 06/03/2014] [Accepted: 06/17/2014] [Indexed: 11/30/2022]
Abstract
In this study, we identified a polymorphism in the 5'-flanking region of the chicken serotonin transporter (5-HTT) gene. Sequencing analysis revealed that in comparison with the wild-type variant (W), a deleted variant (D) is generated by deletion of four nucleotides (5'-AATT-3') and a single nucleotide change (A→T). Using a polyacrylamide gel electrophoresis system, we found that the 360-bp DNA fragment containing the W variant with the wild-type sequence 5'-AATTAATT-3' shows intrinsic DNA curvature while the 356-bp fragment containing the D variant lacking the four base pairs AATT is not curved. Quantitative real-time RT-PCR and ELISA demonstrated that the expression of 5-HTT in D/D chickens was higher than that in W/W and W/D chickens. In addition, transient transfection experiments with chloramphenicol acetyltransferase reporter gene constructs revealed increased 5-HTT promoter activity mediated by the D variant and a silencer activity of the W variant. Interestingly, females and males with D/D genotype showed significant greater increase in body weight from 6 weeks and 16 weeks of age, respectively, and higher body mass index. Moreover, we found that D/D chickens of both genders were physically more active than W/W and W/D chickens.
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Affiliation(s)
- Loc Phi-van
- Friedrich-Loeffler-Institut (FLI), Institute of Animal Welfare and Animal Husbandry, Celle, Germany
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235
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Henry MD, Costanzo-Garvey DL, Klutho PJ, Lewis RE. Obesity-dependent dysregulation of glucose homeostasis in kinase suppressor of ras 2-/- mice. Physiol Rep 2014; 2:2/7/e12053. [PMID: 24997067 PMCID: PMC4187555 DOI: 10.14814/phy2.12053] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Disruption of KSR2 in humans and mice decreases metabolic rate and induces obesity, coincident with dysregulation of glucose homeostasis. Relative to wild‐type mice, ksr2−/− mice are small prior to weaning with normal glucose tolerance at 6 weeks of age, but demonstrate excess adiposity by 9 weeks and glucose intolerance by 12–14 weeks. Defects in AICAR tolerance, a measure of whole‐body AMPK activation, are detectable only when ksr2−/− mice are obese. Food restriction prevents the obesity of adult ksr2−/− mice and normalizes glucose and AICAR sensitivity. Obesity and glucose intolerance return when ad lib feeding is restored to the diet‐restricted mice, indicating that glucose dysregulation is secondary to obesity in ksr2−/− mice. The phenotype of C57BL/6 ksr2−/− mice, including obesity and obesity‐related dysregulation of glucose homeostasis, recapitulates that of humans with KSR2 mutations, demonstrating the applicability of the C57BL/6 ksr2−/− mouse model to the study of the pathogenesis of human disease. These data implicate KSR2 as a physiological regulator of glucose metabolism during development affecting energy sensing, insulin signaling, and lipid storage, and demonstrate the value of the C57BL/6 ksr2−/− mouse model as a unique and relevant model system in which to develop and test therapeutic targets for the prevention and treatment of obesity, type 2 diabetes, and obesity‐related metabolic disorders. A fraction of individuals with obesity‐induced insulin resistance and diabetes respond to diet with improved glucose metabolism. The phenotype of C57BL/6 ksr2−/− mice, including obesity and obesity‐related dysregulation of glucose homeostasis, recapitulates that of humans with KSR2 mutations. These data show that the glucose intolerance and AICAR insensitivity that accompanies KSR2 disruption in mice is preventable or reversible by diet, suggesting that dietary intervention in humans with KSR2 mutations should have similar effects.
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Affiliation(s)
- MaLinda D Henry
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, Nebraska
| | - Diane L Costanzo-Garvey
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, Nebraska
| | - Paula J Klutho
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, Nebraska
| | - Robert E Lewis
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, Nebraska
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236
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Orban G, Bombardi C, Marino Gammazza A, Colangeli R, Pierucci M, Pomara C, Pessia M, Bucchieri F, Arcangelo B, Smolders I, De Deurwaerdère P, Di Giovanni G. Role(s) of the 5-HT2C receptor in the development of maximal dentate activation in the hippocampus of anesthetized rats. CNS Neurosci Ther 2014; 20:651-61. [PMID: 24935789 PMCID: PMC6493041 DOI: 10.1111/cns.12285] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Revised: 04/23/2014] [Accepted: 04/26/2014] [Indexed: 11/29/2022] Open
Abstract
AIMS Substantial evidence indicates that 5-HT2C receptors are involved in the control of neuronal network excitability and in seizure pathophysiology. Here, we have addressed the relatively unexplored relationship between temporal lobe epilepsy (TLE), the most frequent type of intractable epilepsy, and 5-HT2CRs. METHODS In this study, we investigated this issue using a model of partial complex (limbic) seizures in urethane-anesthetized rat, based on the phenomenon of maximal dentate activation (MDA) using 5-HT2C compounds, electrophysiology, immunohistochemistry, and western blotting techniques. RESULTS The 5-HT2C agonists mCPP (1 mg/kg, i.p) and lorcaserin (3 mg/kg, i.p), but not RO60-0175 (1-3 mg/kg i.p.), were antiepileptogenic reducing the MDA response duration. The selective 5-HT2C antagonist SB242084 (2 mg/kg, i.p) unveiled antiepileptogenic effects of RO60-0175 (3 mg/kg, i.p) but did not alter those induced by mCPP and lorcaserin. Compared with control rats, electrically stimulated rats showed an increase in glutamic acid decarboxylase levels and a heterogeneous decrease in 5-HT2CR immunoreactivity in different hippocampal areas. CONCLUSIONS In our animal model of TLE, mCPP and lorcaserin were anticonvulsant; likely acting on receptor subtypes other than 5-HT2C. Epileptogenesis induced early adaptive changes and reorganization in the 5-HT2CR and GABA systems.
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Affiliation(s)
- Gergely Orban
- Dipartimento di Biomedicina Sperimentale e Neuroscienze ClinicheUniversità degli Studi di PalermoPalermoItaly
- Istituto Euro‐Mediterraneo di Scienza e Tecnologia (IEMEST)PalermoItaly
| | - Cristiano Bombardi
- Department of Veterinary Medical ScienceUniversity of BolognaBolognaItaly
| | - Antonella Marino Gammazza
- Dipartimento di Biomedicina Sperimentale e Neuroscienze ClinicheUniversità degli Studi di PalermoPalermoItaly
- Istituto Euro‐Mediterraneo di Scienza e Tecnologia (IEMEST)PalermoItaly
| | - Roberto Colangeli
- Department of Physiology and BiochemistryUniversity of MaltaMsidaMalta
| | - Massimo Pierucci
- Istituto Euro‐Mediterraneo di Scienza e Tecnologia (IEMEST)PalermoItaly
- Department of Physiology and BiochemistryUniversity of MaltaMsidaMalta
| | - Cristoforo Pomara
- Department of AnatomyFaculty of Medicine and SurgeryUniversity of MaltaMsidaMalta
- Department of Forensic PathologyUniversity of FoggiaFoggiaItaly
| | - Mauro Pessia
- Department of Internal MedicineSection of Human PhysiologyUniversity of PerugiaPerugiaItaly
| | - Fabio Bucchieri
- Dipartimento di Biomedicina Sperimentale e Neuroscienze ClinicheUniversità degli Studi di PalermoPalermoItaly
- Istituto Euro‐Mediterraneo di Scienza e Tecnologia (IEMEST)PalermoItaly
| | - Benigno Arcangelo
- Dipartimento di Biomedicina Sperimentale e Neuroscienze ClinicheUniversità degli Studi di PalermoPalermoItaly
| | - Ilse Smolders
- Center for Neurosciences C4NVrije Universiteit BrusselBrusselsBelgium
| | | | - Giuseppe Di Giovanni
- Istituto Euro‐Mediterraneo di Scienza e Tecnologia (IEMEST)PalermoItaly
- Department of Physiology and BiochemistryUniversity of MaltaMsidaMalta
- School of BiosciencesCardiff UniversityCardiffUK
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237
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Liu C, Lee S, Elmquist JK. Circuits controlling energy balance and mood: inherently intertwined or just complicated intersections? Cell Metab 2014; 19:902-9. [PMID: 24630814 PMCID: PMC4047152 DOI: 10.1016/j.cmet.2014.02.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Recent reports of adverse psychiatric events from seemingly different types of weight loss therapies highlight a previously underestimated overlap between CNS circuits that control energy balance and those that regulate mood. In this Perspective, we discuss a few potential brain sites where the homeostatic and the hedonic pathways may intersect and suggest that a better understanding of both pathways is necessary for the development of more effective and safer antiobesity therapies.
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Affiliation(s)
- Chen Liu
- Division of Hypothalamic Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Syann Lee
- Division of Hypothalamic Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Joel K Elmquist
- Division of Hypothalamic Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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238
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Nyongesa AW, Oduma JA, Nakajima M, Odongo HO, Adoyo PA, al'Absi M. Acute and sub-chronic effects of purified cathinone from khat (Catha edulis) on behavioural profiles in vervet monkeys (Chlorocebus aethiops). Metab Brain Dis 2014; 29:441-9. [PMID: 24154685 DOI: 10.1007/s11011-013-9441-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Accepted: 10/07/2013] [Indexed: 10/26/2022]
Abstract
We investigated the cumulative effects of cathinone on behavioural alterations in single-caged vervet monkeys. Fourteen adult vervets were divided into tests (12 animals) and controls (2 animals), and exposed to escalating doses of cathinone at alternate days of each week for 4 months in presence and absence of cage enrichment. One month of pre-treatment phase served to establish baseline values. Composite behavioural scores of aggression, anxiety, abnormal responses, withdrawal and appetite loss were done. A series of repeated measures analysis of variances were conducted to examine the extent to which cathinone administration was associated with patterns of changes in behavioural data. Results indicate a dose-dependent effect of cathinone on increases of aggression, anxiety, abnormal responses, withdrawal, and appetite loss. The findings demonstrate that at high doses and long-term exposure, cathinone causes behavioural alterations probably via changes in presynaptic striatal dopamine system.
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Affiliation(s)
- Albert W Nyongesa
- Department of Veterinary Anatomy and Physiology, University of Nairobi, P.O Box 30197-00100, Nairobi, Kenya,
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239
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Abstract
Sudden unexpected death in epilepsy (SUDEP) is the leading cause of death in patients with refractory epilepsy, with an estimated 35% lifetime risk in this patient population. There is a surprising lack of awareness among patients and physicians of this increased risk of sudden death: in a recent survey, only 33% of Canadian paediatricians who treated patients with epilepsy knew the term SUDEP. Controversy prevails over whether cardiac arrhythmia or respiratory arrest is more important as the primary cause of death. Effective preventive strategies in high-risk patients will rely on definition of the mechanisms that lead from seizures to death. Here, we summarize evidence for the mechanisms that cause cardiac, respiratory and arousal abnormalities during the ictal and postictal period. We highlight potential cellular mechanisms underlying these abnormalities, such as a defect in the serotonergic system, ictal adenosine release, and changes in autonomic output. We discuss genetic mutations that cause Dravet and long QT syndromes, both of which are linked with increased risk of sudden death. We then highlight possible preventive interventions that are likely to decrease SUDEP incidence, including respiratory monitoring in epilepsy monitoring units and overnight supervision. Finally, we discuss treatments, such as selective serotonin reuptake inhibitors, that might be personalized to a specific genetic or pathological defect.
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240
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Zuccoli ML, Milano G, Leone S, Fucile C, Brasesco PC, Martelli A, Mattioli F. A case report on escitalopram-induced hyperglycaemia in a diabetic patient. Int J Psychiatry Med 2014; 46:195-201. [PMID: 24552042 DOI: 10.2190/pm.46.2.f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The incidence of depression in diabetic patients is quite high; moreover, it has been suggested that the presence of depression itself may increase the risk of diabetes mellitus. Hence, it follows that the simultaneous use of antidiabetic and antidepressant drugs is common. Some clinical evidence indicates that selective serotonin re-uptake inhibitors (SSRIs) could be very useful in treating overweight patients, both with and without diabetes. However, recent deregulation of glucidic metabolism was tested in diabetic subjects treated with antidepressants. Several cases of hyperglycaemia and hypoglycaemia associated with other SSRIs have been published, whereas only one case of escitalopram inducing hyperglycaemia has been noted. The exact mechanism of glucose control impairment in patients taking SSRIs--escitalopram in particular--still remains unclear. We describe a diabetic 83-year-old woman with good glycaemic control (as evinced by glycaemic and glycosylated haemoglobin assay--HbA1c--values) before escitalopram initiation in response to therapy with glibenclamide. Escitalopram resulted in a significantly increased glycaemia values 5 days following administration. Glycaemia values returned to normality only after suspension of escitalopram, despite antidiabetic dosage increase. We report this case to draw attention to escitalopram as a possible cause of glycaemic control loss.
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Affiliation(s)
- M L Zuccoli
- Department of Internal Medicine, Pharmacology and Toxicology UnitUniversity of Genoa, Italy
| | - G Milano
- Department of Internal Medicine, Pharmacology and Toxicology UnitUniversity of Genoa, Italy
| | - S Leone
- Department of Internal Medicine, Pharmacology and Toxicology UnitUniversity of Genoa, Italy
| | - C Fucile
- Department of Internal Medicine, Pharmacology and Toxicology UnitUniversity of Genoa, Italy
| | - P C Brasesco
- Department of Internal Medicine, Pharmacology and Toxicology UnitUniversity of Genoa, Italy
| | - A Martelli
- Department of Internal Medicine, Pharmacology and Toxicology UnitUniversity of Genoa, Italy
| | - F Mattioli
- Department of Internal Medicine, Pharmacology and Toxicology UnitUniversity of Genoa, Italy
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Neelamegam R, Hellenbrand T, Schroeder FA, Wang C, Hooker JM. Imaging evaluation of 5HT2C agonists, [(11)C]WAY-163909 and [(11)C]vabicaserin, formed by Pictet-Spengler cyclization. J Med Chem 2014; 57:1488-94. [PMID: 24491146 PMCID: PMC3983360 DOI: 10.1021/jm401802f] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
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The
serotonin subtype 2C (5HT2C) receptor is an emerging
and promising drug target to treat several disorders of the human
central nervous system. In this current report, two potent and selective
5HT2C full agonists, WAY-163909 (2) and vabicaserin
(3), were radiolabeled with carbon-11 via Pictet–Spengler
cyclization with [11C]formaldehyde and used in positron
emission tomography (PET) imaging. Reaction conditions were optimized
to exclude the major source of isotope dilution caused by the previously
unknown breakdown of N,N-dimethylformamide
(DMF) to formaldehyde at high temperature under mildly acid conditions.
In vivo PET imaging was utilized
to evaluate the pharmacokinetics and distribution of the carbon-11
labeled 5HT2C agonists. Both radiolabeled molecules exhibit
high blood–brain barrier (BBB) penetration and nonspecific
binding, which was unaltered by preadministration of the unlabeled
agonist. Our work demonstrates that Pictet–Spengler cyclization
can be used to label drugs with carbon-11 to study their pharmacokinetics
and for evaluation as PET radiotracers.
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Affiliation(s)
- Ramesh Neelamegam
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School , Charlestown, Massachusetts 02129, United States
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Abstract
Obsessive-compulsive disorder (OCD) and related conditions (trichotillomania, pathological skin-picking, pathological nail-biting) are common and disabling. Current treatment approaches fail to help a significant proportion of patients. Multiple tiers of evidence link these conditions with underlying dysregulation of particular cortico-subcortical circuitry and monoamine systems, which represent targets for treatment. Animal models designed to capture aspects of these conditions are critical for several reasons. First, they help in furthering our understanding of neuroanatomical and neurochemical underpinnings of the obsessive-compulsive (OC) spectrum. Second, they help to account for the brain mechanisms by which existing treatments (pharmacotherapy, psychotherapy, deep brain stimulation) exert their beneficial effects on patients. Third, they inform the search for novel treatments. This article provides a critique of key animal models for selected OC spectrum disorders, beginning with initial work relating to anxiety, but moving on to recent developments in domains of genetic, pharmacological, cognitive, and ethological models. We find that there is a burgeoning literature in these areas with important ramifications, which are considered, along with salient future lines of research.
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243
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Salem V, Bloom SR. Approaches to the pharmacological treatment of obesity. Expert Rev Clin Pharmacol 2014; 3:73-88. [DOI: 10.1586/ecp.09.54] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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245
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Abstract
Sudden unexpected death in epilepsy (SUDEP) is an exceptionally difficult condition to study in humans. Therefore, translational research in animal models has been very important in defining pathophysiological mechanisms of death and identifying potential treatments. These models are helping define whether the primary mechanism of death is cardiac or respiratory. They have also identified a link to the serotonergic system of the brainstem; this, in turn, led to recognition that SUDEP and sudden infant death syndrome (SIDS) may share a common final pathway in the sequence of events that lead to death.
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246
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Meltzer HY, Roth BL. Lorcaserin and pimavanserin: emerging selectivity of serotonin receptor subtype-targeted drugs. J Clin Invest 2013; 123:4986-91. [PMID: 24292660 DOI: 10.1172/jci70678] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Serotonin (5-hydroxytryptamine, or 5-HT) receptors mediate a plethora of physiological phenomena in the brain and the periphery. Additionally, serotonergic dysfunction has been implicated in nearly every neuropsychiatric disorder. The effects of serotonin are mediated by fourteen GPCRs. Both the therapeutic actions and side effects of commonly prescribed drugs are frequently due to nonspecific actions on various 5-HT receptor subtypes. For more than 20 years, the search for clinically efficacious drugs that selectively target 5-HT receptor subtypes has been only occasionally successful. This review provides an overview of 5-HT receptor pharmacology and discusses two recent 5-HT receptor subtype-selective drugs, lorcaserin and pimavanserin, which target the 5HT2C and 5HT2A receptors and provide new treatments for obesity and Parkinson's disease psychosis, respectively.
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247
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Abstract
Body weight is determined by a balance between food intake and energy expenditure. Multiple neural circuits in the brain have evolved to process information about food, food-related cues and food consumption to control feeding behavior. Numerous gastrointestinal endocrine cells produce and secrete satiety hormones in response to food consumption and digestion. These hormones suppress hunger and promote satiation and satiety mainly through hindbrain circuits, thus governing meal-by-meal eating behavior. In contrast, the hypothalamus integrates adiposity signals to regulate long-term energy balance and body weight. Distinct hypothalamic areas and various orexigenic and anorexigenic neurons have been identified to homeostatically regulate food intake. The hypothalamic circuits regulate food intake in part by modulating the sensitivity of the hindbrain to short-term satiety hormones. The hedonic and incentive properties of foods and food-related cues are processed by the corticolimbic reward circuits. The mesolimbic dopamine system encodes subjective "liking" and "wanting" of palatable foods, which is subjected to modulation by the hindbrain and the hypothalamic homeostatic circuits and by satiety and adiposity hormones. Satiety and adiposity hormones also promote energy expenditure by stimulating brown adipose tissue (BAT) activity. They stimulate BAT thermogenesis mainly by increasing the sympathetic outflow to BAT. Many defects in satiety and/or adiposity hormone signaling and in the hindbrain and the hypothalamic circuits have been described and are believed to contribute to the pathogenesis of energy imbalance and obesity.
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Affiliation(s)
- Liangyou Rui
- Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, 48109-0622, USA,
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248
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The role of different serotonin receptor subtypes in seizure susceptibility. Exp Brain Res 2013; 232:347-67. [PMID: 24232860 DOI: 10.1007/s00221-013-3757-0] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2013] [Accepted: 10/27/2013] [Indexed: 10/26/2022]
Abstract
5-Hydroxytryptamine (5-HT) has the most diverse set of receptors in comparison with any other neurotransmitter or hormone in the body. To date, seven families of 5-HT receptors have been characterized. A great number of studies have been published regarding the role of 5-HT and its receptors in seizures. However, with a few exceptions, the net effect of activating or inhibiting each 5-HT receptor subtype on the development or severity of seizures remains controversial. Additionally, the results of studies, which have used knockout animals to investigate the role of 5-HT receptors in seizures, have sometimes been contradictory to those which have used pharmacological tools. The present study aims to review the available data regarding the influence of each receptor subtype on seizure development and, when possible, reconcile between the apparently different results obtained in these studies.
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249
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Abstract
In numerous pathological states, the brain can restrict food intake to a lethal level despite mounting requirements for energy as seen in adolescents with anorexia nervosa. How the brain reduces food intake to the point of death while eating is a cornerstone of survival that remains just as ‘cryptic’ as the association between anorexia and overeating. This review provides a recent snapshot of the neural underpinnings of the rewarding effects of anorexia that may compete with the adaptive decision-making process to eat, and with survival instinct. Among a plethora of factors, impaired activity of the serotonin receptors in the reward system underlies the ability of animals to self-impose food restriction, and the transition from under- to over-eating. However, the triumvirate association between serotonin, overeating and addiction appears unlikely. Considering the implication of the serotonin receptors in the hypothalamus, anorexia and bulimia nervosa could result from an impairment of a ‘synchronic activity’ between the autonomic and voluntary nervous systems.
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Affiliation(s)
- Valérie Compan
- Centre National de la Recherche Scientifique, UnitéMixte de Recherche-5203, Institut de Génomique Fonctionnelle, Montpellier, F-34094, France and Institut National de la Santé et de la Recherche Médicale, U661, Montpellier, F-34094, France and Universités de Montpellier 1 & 2, UMR-5203, Montpellier, F-34094, France and Université de Nîmes, Nîmes, F-30000, France
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250
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Berglund ED, Liu C, Sohn JW, Liu T, Kim MH, Lee CE, Vianna CR, Williams KW, Xu Y, Elmquist JK. Serotonin 2C receptors in pro-opiomelanocortin neurons regulate energy and glucose homeostasis. J Clin Invest 2013; 123:5061-70. [PMID: 24177424 DOI: 10.1172/jci70338] [Citation(s) in RCA: 170] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2013] [Accepted: 08/22/2013] [Indexed: 12/25/2022] Open
Abstract
Energy and glucose homeostasis are regulated by central serotonin 2C receptors. These receptors are attractive pharmacological targets for the treatment of obesity; however, the identity of the serotonin 2C receptor-expressing neurons that mediate the effects of serotonin and serotonin 2C receptor agonists on energy and glucose homeostasis are unknown. Here, we show that mice lacking serotonin 2C receptors (Htr2c) specifically in pro-opiomelanocortin (POMC) neurons had normal body weight but developed glucoregulatory defects including hyperinsulinemia, hyperglucagonemia, hyperglycemia, and insulin resistance. Moreover, these mice did not show anorectic responses to serotonergic agents that suppress appetite and developed hyperphagia and obesity when they were fed a high-fat/high-sugar diet. A requirement of serotonin 2C receptors in POMC neurons for the maintenance of normal energy and glucose homeostasis was further demonstrated when Htr2c loss was induced in POMC neurons in adult mice using a tamoxifen-inducible POMC-cre system. These data demonstrate that serotonin 2C receptor-expressing POMC neurons are required to control energy and glucose homeostasis and implicate POMC neurons as the target for the effect of serotonin 2C receptor agonists on weight-loss induction and improved glycemic control.
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