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Pitra S, Feng Y, Stern JE. Mechanisms underlying prorenin actions on hypothalamic neurons implicated in cardiometabolic control. Mol Metab 2016; 5:858-868. [PMID: 27688999 PMCID: PMC5034613 DOI: 10.1016/j.molmet.2016.07.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Revised: 07/26/2016] [Accepted: 07/27/2016] [Indexed: 02/07/2023] Open
Abstract
Background Hypertension and obesity are highly interrelated diseases, being critical components of the metabolic syndrome. Despite the growing prevalence of this syndrome in the world population, efficient therapies are still missing. Thus, identification of novel targets and therapies are warranted. An enhanced activity of the hypothalamic renin-angiotensin system (RAS), including the recently discovered prorenin (PR) and its receptor (PRR), has been implicated as a common mechanism underlying aberrant sympatho-humoral activation that contributes to both metabolic and cardiovascular dysregulation in the metabolic syndrome. Still, the identification of precise neuronal targets, cellular mechanisms and signaling pathways underlying PR/PRR actions in cardiovascular- and metabolic related hypothalamic nuclei remain unknown. Methods and results Using a multidisciplinary approach including patch-clamp electrophysiology, live calcium imaging and immunohistochemistry, we aimed to elucidate cellular mechanisms underlying PR/PRR actions within the hypothalamic supraoptic (SON) and paraventricular nucleus (PVN), key brain areas previously involved in cardiometabolic regulation. We show for the first time that PRR is expressed in magnocellular neurosecretory cells (MNCs), and to a lesser extent, in presympathetic PVN neurons (PVNPS). Moreover, we show that while PRR activation efficiently stimulates the firing activity of both MNCs and PVNPS neurons, these effects involved AngII-independent and AngII-dependent mechanisms, respectively. In both cases however, PR excitatory effects involved an increase in intracellular Ca2+ levels and a Ca2+-dependent inhibition of a voltage-gated K+ current. Conclusions We identified novel neuronal targets and cellular mechanisms underlying PR/PRR actions in critical hypothalamic neurons involved in cardiometabolic regulation. This fundamental mechanistic information regarding central PR/PRR actions is essential for the development of novel RAS-based therapeutic targets for the treatment of cardiometabolic disorders in obesity and hypertension. PRR is expressed in SON and PVN neurosecretory and presympathetic neurons. PRR activation stimulates firing activity of SON and PVN neurons. PR/PRR effects on neurosecretory neurons are AngII-independent. PR/PRR effects on presympathetic neurons are AngII-dependent. PR inhibits a voltage-gated K+ current in a Ca2+-dependent manner.
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Affiliation(s)
- Soledad Pitra
- Department of Physiology, Medical College of Georgia, Augusta University, United States
| | - Yumei Feng
- Departments of Pharmacology, Physiology and Cell Biology, Center for Cardiovascular Research, University of Nevada School of Medicine, United States
| | - Javier E Stern
- Department of Physiology, Medical College of Georgia, Augusta University, United States.
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Tabe-Bordbar S, Anastasio TJ. Computational Analysis of the Hypothalamic Control of Food Intake. Front Comput Neurosci 2016; 10:27. [PMID: 27199725 PMCID: PMC4844610 DOI: 10.3389/fncom.2016.00027] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Accepted: 03/14/2016] [Indexed: 12/01/2022] Open
Abstract
Food-intake control is mediated by a heterogeneous network of different neural subtypes, distributed over various hypothalamic nuclei and other brain structures, in which each subtype can release more than one neurotransmitter or neurohormone. The complexity of the interactions of these subtypes poses a challenge to understanding their specific contributions to food-intake control, and apparent consistencies in the dataset can be contradicted by new findings. For example, the growing consensus that arcuate nucleus neurons expressing Agouti-related peptide (AgRP neurons) promote feeding, while those expressing pro-opiomelanocortin (POMC neurons) suppress feeding, is contradicted by findings that low AgRP neuron activity and high POMC neuron activity can be associated with high levels of food intake. Similarly, the growing consensus that GABAergic neurons in the lateral hypothalamus suppress feeding is contradicted by findings suggesting the opposite. Yet the complexity of the food-intake control network admits many different network behaviors. It is possible that anomalous associations between the responses of certain neural subtypes and feeding are actually consistent with known interactions, but their effect on feeding depends on the responses of the other neural subtypes in the network. We explored this possibility through computational analysis. We made a computer model of the interactions between the hypothalamic and other neural subtypes known to be involved in food-intake control, and optimized its parameters so that model behavior matched observed behavior over an extensive test battery. We then used specialized computational techniques to search the entire model state space, where each state represents a different configuration of the responses of the units (model neural subtypes) in the network. We found that the anomalous associations between the responses of certain hypothalamic neural subtypes and feeding are actually consistent with the known structure of the food-intake control network, and we could specify the ways in which the anomalous configurations differed from the expected ones. By analyzing the temporal relationships between different states we identified the conditions under which the anomalous associations can occur, and these stand as model predictions.
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Affiliation(s)
- Shayan Tabe-Bordbar
- Computational Neurobiology Laboratory, Department of Molecular and Integrative Physiology, Beckman Institute, University of Illinois at Urbana-Champaign Urbana, IL, USA
| | - Thomas J Anastasio
- Computational Neurobiology Laboratory, Department of Molecular and Integrative Physiology, Beckman Institute, University of Illinois at Urbana-Champaign Urbana, IL, USA
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Barson JR, Leibowitz SF. Hypothalamic neuropeptide signaling in alcohol addiction. Prog Neuropsychopharmacol Biol Psychiatry 2016; 65:321-9. [PMID: 25689818 PMCID: PMC4537397 DOI: 10.1016/j.pnpbp.2015.02.006] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Revised: 01/30/2015] [Accepted: 02/09/2015] [Indexed: 11/27/2022]
Abstract
The hypothalamus is now known to regulate alcohol intake in addition to its established role in food intake, in part through neuromodulatory neurochemicals termed neuropeptides. Certain orexigenic neuropeptides act in the hypothalamus to promote alcohol drinking, although they affect different aspects of the drinking response. These neuropeptides, which include galanin, the endogenous opioid enkephalin, and orexin/hypocretin, appear to stimulate alcohol intake not only through mechanisms that promote food intake but also by enhancing reward and reinforcement from alcohol. Moreover, these neuropeptides participate in a positive feedback relationship with alcohol, whereby they are upregulated by alcohol intake to promote even further consumption. They contrast with other orexigenic neuropeptides, such as melanin-concentrating hormone and neuropeptide Y, which promote alcohol intake under limited circumstances, are not consistently stimulated by alcohol, and do not enhance reward. They also contrast with neuropeptides that can be anorexigenic, including the endogenous opioid dynorphin, corticotropin-releasing factor, and melanocortins, which act in the hypothalamus to inhibit alcohol drinking as well as reward and therefore counter the ingestive drive promoted by orexigenic neuropeptides. Thus, while multiple hypothalamic neuropeptides may work together to regulate different aspects of the alcohol drinking response, excessive signaling from orexigenic neuropeptides or inadequate signaling from anorexigenic neuropeptides can therefore allow alcohol drinking to become dysregulated.
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Affiliation(s)
- Jessica R. Barson
- Laboratory of Behavioral Neurobiology, The Rockefeller University, 1230 York Avenue, Box 278, New York, NY, 10065 USA
| | - Sarah F. Leibowitz
- Laboratory of Behavioral Neurobiology, The Rockefeller University, 1230 York Avenue, Box 278, New York, NY, 10065 USA
,Corresponding author at: Laboratory of Behavioral Neurobiology, The Rockefeller University, 1230 York Avenue, Box 278, New York, NY, 10065 USA. Tel.: +1 212 327 8378; fax: +1 212 327 8447
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Torterolo P, Scorza C, Lagos P, Urbanavicius J, Benedetto L, Pascovich C, López-Hill X, Chase MH, Monti JM. Melanin-Concentrating Hormone (MCH): Role in REM Sleep and Depression. Front Neurosci 2015; 9:475. [PMID: 26733789 PMCID: PMC4681773 DOI: 10.3389/fnins.2015.00475] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2015] [Accepted: 11/26/2015] [Indexed: 12/05/2022] Open
Abstract
The melanin-concentrating hormone (MCH) is a peptidergic neuromodulator synthesized by neurons of the lateral sector of the posterior hypothalamus and zona incerta. MCHergic neurons project throughout the central nervous system, including areas such as the dorsal (DR) and median (MR) raphe nuclei, which are involved in the control of sleep and mood. Major Depression (MD) is a prevalent psychiatric disease diagnosed on the basis of symptomatic criteria such as sadness or melancholia, guilt, irritability, and anhedonia. A short REM sleep latency (i.e., the interval between sleep onset and the first REM sleep period), as well as an increase in the duration of REM sleep and the density of rapid-eye movements during this state, are considered important biological markers of depression. The fact that the greatest firing rate of MCHergic neurons occurs during REM sleep and that optogenetic stimulation of these neurons induces sleep, tends to indicate that MCH plays a critical role in the generation and maintenance of sleep, especially REM sleep. In addition, the acute microinjection of MCH into the DR promotes REM sleep, while immunoneutralization of this peptide within the DR decreases the time spent in this state. Moreover, microinjections of MCH into either the DR or MR promote a depressive-like behavior. In the DR, this effect is prevented by the systemic administration of antidepressant drugs (either fluoxetine or nortriptyline) and blocked by the intra-DR microinjection of a specific MCH receptor antagonist. Using electrophysiological and microdialysis techniques we demonstrated also that MCH decreases the activity of serotonergic DR neurons. Therefore, there are substantive experimental data suggesting that the MCHergic system plays a role in the control of REM sleep and, in addition, in the pathophysiology of depression. Consequently, in the present report, we summarize and evaluate the current data and hypotheses related to the role of MCH in REM sleep and MD.
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Affiliation(s)
- Pablo Torterolo
- Department of Physiology, School of Medicine, Universidad de la República Montevideo, Uruguay
| | - Cecilia Scorza
- Department of Experimental Neuropharmacology, Instituto de Investigaciones Biológicas Clemente Estable Montevideo, Uruguay
| | - Patricia Lagos
- Department of Physiology, School of Medicine, Universidad de la República Montevideo, Uruguay
| | - Jessika Urbanavicius
- Department of Experimental Neuropharmacology, Instituto de Investigaciones Biológicas Clemente Estable Montevideo, Uruguay
| | - Luciana Benedetto
- Department of Physiology, School of Medicine, Universidad de la República Montevideo, Uruguay
| | - Claudia Pascovich
- Department of Physiology, School of Medicine, Universidad de la República Montevideo, Uruguay
| | - Ximena López-Hill
- Department of Experimental Neuropharmacology, Instituto de Investigaciones Biológicas Clemente Estable Montevideo, Uruguay
| | - Michael H Chase
- WebSciences International and University of California, Los Angeles School of Medicine Los Angeles, CA, USA
| | - Jaime M Monti
- Department of Pharmacology and Therapeutics, School of Medicine, Hospital de Clínicas, Universidad de la República Montevideo, Uruguay
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Dias Abdo Agamme AL, Aguilar Calegare BF, Fernandes L, Costa A, Lagos P, Torterolo P, D'Almeida V. MCH levels in the CSF, brain preproMCH and MCHR1 gene expression during paradoxical sleep deprivation, sleep rebound and chronic sleep restriction. Peptides 2015; 74:9-15. [PMID: 26456505 DOI: 10.1016/j.peptides.2015.10.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Revised: 10/02/2015] [Accepted: 10/06/2015] [Indexed: 01/07/2023]
Abstract
Neurons that utilize melanin-concentrating hormone (MCH) as neuromodulator are located in the lateral hypothalamus and incerto-hypothalamic area. These neurons project throughout the central nervous system and play a role in sleep regulation. With the hypothesis that the MCHergic system function would be modified by the time of the day as well as by disruptions of the sleep-wake cycle, we quantified in rats the concentration of MCH in the cerebrospinal fluid (CSF), the expression of the MCH precursor (Pmch) gene in the hypothalamus, and the expression of the MCH receptor 1 (Mchr1) gene in the frontal cortex and hippocampus. These analyses were performed during paradoxical sleep deprivation (by a modified multiple platform technique), paradoxical sleep rebound and chronic sleep restriction, both at the end of the active (dark) phase (lights were turned on at Zeitgeber time zero, ZT0) and during the inactive (light) phase (ZT8). We observed that in control condition (waking and sleep ad libitum), Mchr1 gene expression was larger at ZT8 (when sleep predominates) than at ZT0, both in frontal cortex and hippocampus. In addition, compared to control, disturbances of the sleep-wake cycle produced the following effects: paradoxical sleep deprivation for 96 and 120 h reduced the expression of Mchr1 gene in frontal cortex at ZT0. Sleep rebound that followed 96 h of paradoxical sleep deprivation increased the MCH concentration in the CSF also at ZT0. Twenty-one days of sleep restriction produced a significant increment in MCH CSF levels at ZT8. Finally, sleep disruptions unveiled day/night differences in MCH CSF levels and in Pmch gene expression that were not observed in control (undisturbed) conditions. In conclusion, the time of the day and sleep disruptions produced subtle modifications in the physiology of the MCHergic system.
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Affiliation(s)
| | | | - Leandro Fernandes
- Department of Psychobiology, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Alicia Costa
- Department of Physiology, School of Medicine, Universidad de la República, Montevideo, Uruguay
| | - Patricia Lagos
- Department of Physiology, School of Medicine, Universidad de la República, Montevideo, Uruguay
| | - Pablo Torterolo
- Department of Physiology, School of Medicine, Universidad de la República, Montevideo, Uruguay.
| | - Vânia D'Almeida
- Department of Psychobiology, Universidade Federal de São Paulo, São Paulo, Brazil
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56
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Varin C, Arthaud S, Salvert D, Gay N, Libourel PA, Luppi PH, Léger L, Fort P. Sleep architecture and homeostasis in mice with partial ablation of melanin-concentrating hormone neurons. Behav Brain Res 2015; 298:100-10. [PMID: 26529469 DOI: 10.1016/j.bbr.2015.10.051] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Revised: 10/23/2015] [Accepted: 10/25/2015] [Indexed: 12/23/2022]
Abstract
Recent reports support a key role of tuberal hypothalamic neurons secreting melanin concentrating-hormone (MCH) in the promotion of Paradoxical Sleep (PS). Controversies remain concerning their concomitant involvement in Slow-Wave Sleep (SWS). We studied the effects of their selective loss achieved by an Ataxin 3-mediated ablation strategy to decipher the contribution of MCH neurons to SWS and/or PS. Polysomnographic recordings were performed on male adult transgenic mice expressing Ataxin-3 transgene within MCH neurons (MCH(Atax)) and their wild-type littermates (MCH(WT)) bred on two genetic backgrounds (FVB/N and C57BL/6). Compared to MCH(WT) mice, MCH(Atax) mice were characterized by a significant drop in MCH mRNAs (-70%), a partial loss of MCH-immunoreactive neurons (-30%) and a marked reduction in brain density of MCH-immunoreactive fibers. Under basal condition, such MCH(Atax) mice exhibited higher PS amounts during the light period and a pronounced SWS fragmentation without any modification of SWS quantities. Moreover, SWS and PS rebounds following 4-h total sleep deprivation were quantitatively similar in MCH(Atax)vs. MCH(WT) mice. Additionally, MCH(Atax) mice were unable to consolidate SWS and increase slow-wave activity (SWA) in response to this homeostatic challenge as observed in MCH(WT) littermates. Here, we show that the partial loss of MCH neurons is sufficient to disturb the fine-tuning of sleep. Our data provided new insights into their contribution to subtle process managing SWS quality and its efficiency rather than SWS quantities, as evidenced by the deleterious impact on two powerful markers of sleep depth, i.e., SWS consolidation/fragmentation and SWA intensity under basal condition and under high sleep pressure.
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Affiliation(s)
- Christophe Varin
- Neuroscience Research Center of Lyon (CRNL), CNRS UMR 5292, INSERM U1028, SLEEP Team, Lyon, France; Université Claude Bernard, Lyon 1, Lyon, France
| | - Sébastien Arthaud
- Neuroscience Research Center of Lyon (CRNL), CNRS UMR 5292, INSERM U1028, SLEEP Team, Lyon, France; Université Claude Bernard, Lyon 1, Lyon, France
| | - Denise Salvert
- Neuroscience Research Center of Lyon (CRNL), CNRS UMR 5292, INSERM U1028, SLEEP Team, Lyon, France; Université Claude Bernard, Lyon 1, Lyon, France
| | - Nadine Gay
- Neuroscience Research Center of Lyon (CRNL), CNRS UMR 5292, INSERM U1028, SLEEP Team, Lyon, France; Université Claude Bernard, Lyon 1, Lyon, France
| | - Paul-Antoine Libourel
- Neuroscience Research Center of Lyon (CRNL), CNRS UMR 5292, INSERM U1028, SLEEP Team, Lyon, France; Université Claude Bernard, Lyon 1, Lyon, France
| | - Pierre-Hervé Luppi
- Neuroscience Research Center of Lyon (CRNL), CNRS UMR 5292, INSERM U1028, SLEEP Team, Lyon, France; Université Claude Bernard, Lyon 1, Lyon, France
| | - Lucienne Léger
- Neuroscience Research Center of Lyon (CRNL), CNRS UMR 5292, INSERM U1028, SLEEP Team, Lyon, France; Université Claude Bernard, Lyon 1, Lyon, France
| | - Patrice Fort
- Neuroscience Research Center of Lyon (CRNL), CNRS UMR 5292, INSERM U1028, SLEEP Team, Lyon, France; Université Claude Bernard, Lyon 1, Lyon, France.
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Chee MJS, Douris N, Forrow AB, Monnard A, Lu S, Flaherty SE, Adams AC, Maratos-Flier E. Melanin-concentrating hormone is necessary for olanzapine-inhibited locomotor activity in male mice. Eur Neuropsychopharmacol 2015; 25:1808-16. [PMID: 26092201 PMCID: PMC4609648 DOI: 10.1016/j.euroneuro.2015.05.010] [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: 01/17/2015] [Revised: 04/07/2015] [Accepted: 05/25/2015] [Indexed: 01/01/2023]
Abstract
Olanzapine (OLZ), an atypical antipsychotic, can be effective in treating patients with restricting type anorexia nervosa who exercise excessively. Clinical improvements include weight gain and reduced pathological hyperactivity. However the neuronal populations and mechanisms underlying OLZ actions are not known. We studied the effects of OLZ on hyperactivity using male mice lacking the hypothalamic neuropeptide melanin-concentrating hormone (MCHKO) that are lean and hyperactive. We compared the in vivo effects of systemic or intra-accumbens nucleus (Acb) OLZ administration on locomotor activity in WT and MCHKO littermates. Acute systemic OLZ treatment in WT mice significantly reduced locomotor activity, an effect that is substantially attenuated in MCHKO mice. Furthermore, OLZ infusion directly into the Acb of WT mice reduced locomotor activity, but not in MCHKO mice. To identify contributing neuronal mechanisms, we assessed the effect of OLZ treatment on Acb synaptic transmission ex vivo and in vitro. Intraperitoneal OLZ treatment reduced Acb GABAergic activity in WT but not MCHKO neurons. This effect was also seen in vitro by applying OLZ to acute brain slices. OLZ reduced the frequency and amplitude of GABAergic activity that was more robust in WT than MCHKO Acb. These findings indicate that OLZ reduced Acb GABAergic transmission and that MCH is necessary for the hypolocomotor effects of OLZ.
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Affiliation(s)
- Melissa J S Chee
- Division of Endocrinology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA
| | - Nicholas Douris
- Division of Endocrinology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA
| | - Avery B Forrow
- Division of Endocrinology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA
| | - Arnaud Monnard
- Division of Endocrinology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA
| | - Shuangyu Lu
- Division of Endocrinology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA
| | - Stephen E Flaherty
- Division of Endocrinology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA
| | - Andrew C Adams
- Division of Endocrinology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA
| | - Eleftheria Maratos-Flier
- Division of Endocrinology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA.
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Melanin-concentrating hormone neurons release glutamate for feedforward inhibition of the lateral septum. J Neurosci 2015; 35:3644-51. [PMID: 25716862 DOI: 10.1523/jneurosci.4187-14.2015] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Melanin-concentrating hormone (MCH) regulates vital physiological functions, including energy balance and sleep. MCH cells are thought to be GABAergic, releasing GABA to inhibit downstream targets. However, there is little experimental support for this paradigm. To better understand the synaptic mechanisms of mouse MCH neurons, we performed neuroanatomical mapping and characterization followed by optogenetics to test their functional connectivity at downstream targets. Synaptophysin-mediated projection mapping showed that the lateral septal nucleus (LS) contained the densest accumulation of MCH nerve terminals. We then expressed channel rhodopsin-2 in MCH neurons and photostimulated MCH projections to determine their effect on LS activity. Photostimulation of MCH projections evoked a monosynaptic glutamate release in the LS. Interestingly, this led to a feedforward inhibition that depressed LS firing by a robust secondary GABA release. This study presents a circuit analysis between MCH and LS neurons and confirms their functional connection via monosynaptic and polysynaptic pathways. Our findings indicate that MCH neurons are not exclusively GABAergic and reveal a glutamate-mediated, feedforward mechanism that inhibits LS cells.
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Abstract
Sleep and wake are fundamental behavioral states whose molecular regulation remains mysterious. Brain states and body functions change dramatically between sleep and wake, are regulated by circadian and homeostatic processes, and depend on the nutritional and emotional condition of the animal. Sleep-wake transitions require the coordination of several brain regions and engage multiple neurochemical systems, including neuropeptides. Neuropeptides serve two main functions in sleep-wake regulation. First, they represent physiological states such as energy level or stress in response to environmental and internal stimuli. Second, neuropeptides excite or inhibit their target neurons to induce, stabilize, or switch between sleep-wake states. Thus, neuropeptides integrate physiological subsystems such as circadian time, previous neuron usage, energy homeostasis, and stress and growth status to generate appropriate sleep-wake behaviors. We review the roles of more than 20 neuropeptides in sleep and wake to lay the foundation for future studies uncovering the mechanisms that underlie the initiation, maintenance, and exit of sleep and wake states.
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Affiliation(s)
- Constance Richter
- Department of Molecular and Cellular Biology, Center for Brain Science, Division of Sleep Biology, Harvard University, Cambridge, Massachusetts 02138; ,
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Brown JA, Woodworth HL, Leinninger GM. To ingest or rest? Specialized roles of lateral hypothalamic area neurons in coordinating energy balance. Front Syst Neurosci 2015; 9:9. [PMID: 25741247 PMCID: PMC4332303 DOI: 10.3389/fnsys.2015.00009] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Accepted: 01/15/2015] [Indexed: 12/26/2022] Open
Abstract
Survival depends on an organism’s ability to sense nutrient status and accordingly regulate intake and energy expenditure behaviors. Uncoupling of energy sensing and behavior, however, underlies energy balance disorders such as anorexia or obesity. The hypothalamus regulates energy balance, and in particular the lateral hypothalamic area (LHA) is poised to coordinate peripheral cues of energy status and behaviors that impact weight, such as drinking, locomotor behavior, arousal/sleep and autonomic output. There are several populations of LHA neurons that are defined by their neuropeptide content and contribute to energy balance. LHA neurons that express the neuropeptides melanin-concentrating hormone (MCH) or orexins/hypocretins (OX) are best characterized and these neurons play important roles in regulating ingestion, arousal, locomotor behavior and autonomic function via distinct neuronal circuits. Recently, another population of LHA neurons containing the neuropeptide Neurotensin (Nts) has been implicated in coordinating anorectic stimuli and behavior to regulate hydration and energy balance. Understanding the specific roles of MCH, OX and Nts neurons in harmonizing energy sensing and behavior thus has the potential to inform pharmacological strategies to modify behaviors and treat energy balance disorders.
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Affiliation(s)
- Juliette A Brown
- Department of Pharmacology and Toxicology, Michigan State University East Lansing, MI, USA ; Center for Integrative Toxicology East Lansing, MI, USA
| | | | - Gina M Leinninger
- Center for Integrative Toxicology East Lansing, MI, USA ; Department of Physiology, Michigan State University East Lansing, MI, USA
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Abstract
This paper is the thirty-sixth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2013 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior, and the roles of these opioid peptides and receptors in pain and analgesia; stress and social status; tolerance and dependence; learning and memory; eating and drinking; alcohol and drugs of abuse; sexual activity and hormones, pregnancy, development and endocrinology; mental illness and mood; seizures and neurologic disorders; electrical-related activity and neurophysiology; general activity and locomotion; gastrointestinal, renal and hepatic functions; cardiovascular responses; respiration and thermoregulation; and immunological responses.
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Affiliation(s)
- Richard J Bodnar
- Department of Psychology and Neuropsychology Doctoral Sub-Program, Queens College, City University of New York, Flushing, NY 11367, United States.
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Smith CM, Walker AW, Hosken IT, Chua BE, Zhang C, Haidar M, Gundlach AL. Relaxin-3/RXFP3 networks: an emerging target for the treatment of depression and other neuropsychiatric diseases? Front Pharmacol 2014; 5:46. [PMID: 24711793 PMCID: PMC3968750 DOI: 10.3389/fphar.2014.00046] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2013] [Accepted: 02/28/2014] [Indexed: 12/17/2022] Open
Abstract
Animal and clinical studies of gene-environment interactions have helped elucidate the mechanisms involved in the pathophysiology of several mental illnesses including anxiety, depression, and schizophrenia; and have led to the discovery of improved treatments. The study of neuropeptides and their receptors is a parallel frontier of neuropsychopharmacology research and has revealed the involvement of several peptide systems in mental illnesses and identified novel targets for their treatment. Relaxin-3 is a newly discovered neuropeptide that binds, and activates the G-protein coupled receptor, RXFP3. Existing anatomical and functional evidence suggests relaxin-3 is an arousal transmitter which is highly responsive to environmental stimuli, particularly neurogenic stressors, and in turn modulates behavioral responses to these stressors and alters key neural processes, including hippocampal theta rhythm and associated learning and memory. Here, we review published experimental data on relaxin-3/RXFP3 systems in rodents, and attempt to highlight aspects that are relevant and/or potentially translatable to the etiology and treatment of major depression and anxiety. Evidence pertinent to autism spectrum and metabolism/eating disorders, or related psychiatric conditions, is also discussed. We also nominate some key experimental studies required to better establish the therapeutic potential of this intriguing neuromodulatory signaling system, including an examination of the impact of RXFP3 agonists and antagonists on the overall activity of distinct or common neural substrates and circuitry that are identified as dysfunctional in these debilitating brain diseases.
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Affiliation(s)
- Craig M Smith
- Peptide Neurobiology Laboratory, Neuropeptides Division, The Florey Institute of Neuroscience and Mental Health, The University of Melbourne VIC, Australia ; Florey Department of Neuroscience and Mental Health, The University of Melbourne VIC, Australia
| | - Andrew W Walker
- Peptide Neurobiology Laboratory, Neuropeptides Division, The Florey Institute of Neuroscience and Mental Health, The University of Melbourne VIC, Australia ; Florey Department of Neuroscience and Mental Health, The University of Melbourne VIC, Australia
| | - Ihaia T Hosken
- Peptide Neurobiology Laboratory, Neuropeptides Division, The Florey Institute of Neuroscience and Mental Health, The University of Melbourne VIC, Australia ; Florey Department of Neuroscience and Mental Health, The University of Melbourne VIC, Australia
| | - Berenice E Chua
- Peptide Neurobiology Laboratory, Neuropeptides Division, The Florey Institute of Neuroscience and Mental Health, The University of Melbourne VIC, Australia
| | - Cary Zhang
- Peptide Neurobiology Laboratory, Neuropeptides Division, The Florey Institute of Neuroscience and Mental Health, The University of Melbourne VIC, Australia ; Florey Department of Neuroscience and Mental Health, The University of Melbourne VIC, Australia
| | - Mouna Haidar
- Peptide Neurobiology Laboratory, Neuropeptides Division, The Florey Institute of Neuroscience and Mental Health, The University of Melbourne VIC, Australia ; Florey Department of Neuroscience and Mental Health, The University of Melbourne VIC, Australia
| | - Andrew L Gundlach
- Peptide Neurobiology Laboratory, Neuropeptides Division, The Florey Institute of Neuroscience and Mental Health, The University of Melbourne VIC, Australia ; Florey Department of Neuroscience and Mental Health, The University of Melbourne VIC, Australia ; Department of Anatomy and Neuroscience, The University of Melbourne VIC, Australia
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Chee MJS, Pissios P, Prasad D, Maratos-Flier E. Expression of melanin-concentrating hormone receptor 2 protects against diet-induced obesity in male mice. Endocrinology 2014; 155:81-8. [PMID: 24169555 PMCID: PMC3868808 DOI: 10.1210/en.2013-1738] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Melanin-concentrating hormone (MCH) is an orexigenic neuropeptide that is a ligand for two subtypes of MCH receptors, MCHR1 and MCHR2. MCHR1 is universally expressed in mammals ranging from rodents to humans, but the expression of MCHR2 is substantially restricted. In mammals, MCHR2 has been defined in primates as well as other species such as cats and dogs but is not seen in rodents. Although the role of MCHR1 in mediating the actions of MCH on energy balance is clearly defined using mouse models, the role of MCHR2 is harder to characterize because of its limited expression. To determine any potential role of MCHR2 in energy balance, we generated a transgenic MCHR1R2 mouse model, where human MCHR2 is coexpressed in MCHR1-expressing neurons. As shown previously, control wild-type mice expressing only native MCHR1 developed diet-induced obesity when fed a high-fat diet. In contrast, MCHR1R2 mice had lower food intake, leading to their resistance to diet-induced obesity. Furthermore, we showed that MCH action is altered in MCHR1R2 mice. MCH treatment in wild-type mice inhibited the activation of the immediate-early gene c-fos, and coexpression of MCHR2 reduced the inhibitory actions of MCHR1 on this pathway. In conclusion, we developed an experimental animal model that can provide insight into the action of MCHR2 in the central nervous system and suggest that some actions of MCHR2 oppose the endogenous actions of MCHR1.
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Affiliation(s)
- Melissa J S Chee
- Division of Endocrinology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts 02215
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Jego S, Glasgow SD, Herrera CG, Ekstrand M, Reed SJ, Boyce R, Friedman J, Burdakov D, Adamantidis AR. Optogenetic identification of a rapid eye movement sleep modulatory circuit in the hypothalamus. Nat Neurosci 2013; 16:1637-43. [PMID: 24056699 PMCID: PMC4974078 DOI: 10.1038/nn.3522] [Citation(s) in RCA: 289] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Accepted: 08/23/2013] [Indexed: 12/22/2022]
Abstract
Rapid-Eye Movement (REM) sleep correlates with neuronal activity in the brainstem, basal forebrain and lateral hypothalamus (LH). LH melanin-concentrating hormone (MCH)-expressing neurons are active during sleep, however, their action on REM sleep remains unclear. Using optogenetic tools in newly-generated Tg(Pmch-Cre) mice, we found that acute activation of MCH neurons (ChETA, SSFO) at the onset of REM sleep extended the duration of REM, but not non-REM sleep episode. In contrast, their acute silencing (eNpHR3.0, ArchT) reduced the frequency and amplitude of hippocampal theta rhythm, without affecting REM sleep duration. In vitro activation of MCH neuron terminals induced GABAA-mediated inhibitory post-synaptic currents (IPSCs) in wake-promoting histaminergic neurons of the tuberomammillary nucleus (TMN), while in vivo activation of MCH neuron terminals in TMN or medial septum also prolonged REM sleep episodes. Collectively, these results suggest that activation of MCH neurons maintains REM sleep, possibly through inhibition of arousal circuits in the mammalian brain.
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Affiliation(s)
- Sonia Jego
- Douglas Institute, Department of Psychiatry, McGill University, Montreal, Canada
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65
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Melanin-concentrating hormone regulates beat frequency of ependymal cilia and ventricular volume. Nat Neurosci 2013; 16:845-7. [PMID: 23708141 DOI: 10.1038/nn.3401] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2013] [Accepted: 04/18/2013] [Indexed: 12/15/2022]
Abstract
Ependymal cell cilia help move cerebrospinal fluid through the cerebral ventricles, but the regulation of their beat frequency remains unclear. Using in vitro, high-speed video microscopy and in vivo magnetic resonance imaging in mice, we found that the metabolic peptide melanin-concentrating hormone (MCH) positively controlled cilia beat frequency, specifically in the ventral third ventricle, whereas a lack of MCH receptor provoked a ventricular size increase.
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Conductier G, Martin AO, Risold PY, Jego S, Lavoie R, Lafont C, Mollard P, Adamantidis A, Nahon JL. Control of ventricular ciliary beating by the melanin concentrating hormone-expressing neurons of the lateral hypothalamus: a functional imaging survey. Front Endocrinol (Lausanne) 2013; 4:182. [PMID: 24324458 PMCID: PMC3839296 DOI: 10.3389/fendo.2013.00182] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Accepted: 11/07/2013] [Indexed: 12/26/2022] Open
Abstract
The cyclic peptide Melanin Concentrating Hormone (MCH) is known to control a large number of brain functions in mammals such as food intake and metabolism, stress response, anxiety, sleep/wake cycle, memory, and reward. Based on neuro-anatomical and electrophysiological studies these functions were attributed to neuronal circuits expressing MCHR1, the single MCH receptor in rodents. In complement to our recently published work (1) we provided here new data regarding the action of MCH on ependymocytes in the mouse brain. First, we establish that MCHR1 mRNA is expressed in the ependymal cells of the third ventricle epithelium. Second, we demonstrated a tonic control of MCH-expressing neurons on ependymal cilia beat frequency using in vitro optogenics. Finally, we performed in vivo measurements of CSF flow using fluorescent micro-beads in wild-type and MCHR1-knockout mice. Collectively, our results demonstrated that MCH-expressing neurons modulate ciliary beating of ependymal cells at the third ventricle and could contribute to maintain cerebro-spinal fluid homeostasis.
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Affiliation(s)
- Grégory Conductier
- UMR7275, Institut de Pharmacologie Moléculaire et Cellulaire, Centre National de la Recherche Scientifique, Valbonne, France
- University of Nice Sophia Antipolis, Nice, France
| | - Agnès O. Martin
- UMR5203, Institut de Génomique Fonctionnelle, Centre National de la Recherche Scientifique, Montpellier, France
- U661, INSERM, Montpellier, France
- UMR-5203, Universités de Montpellier 1 & 2, Montpellier, France
| | - Pierre-Yves Risold
- Laboratoire d’Histologie, IFR 133, Faculté de Médecine et de Pharmacie, Besançon, France
| | - Sonia Jego
- Douglas Mental Health University Institute, Montreal, QC, Canada
| | - Raphaël Lavoie
- Douglas Mental Health University Institute, Montreal, QC, Canada
| | - Chrystel Lafont
- UMR5203, Institut de Génomique Fonctionnelle, Centre National de la Recherche Scientifique, Montpellier, France
- U661, INSERM, Montpellier, France
- UMR-5203, Universités de Montpellier 1 & 2, Montpellier, France
| | - Patrice Mollard
- UMR5203, Institut de Génomique Fonctionnelle, Centre National de la Recherche Scientifique, Montpellier, France
- U661, INSERM, Montpellier, France
- UMR-5203, Universités de Montpellier 1 & 2, Montpellier, France
| | | | - Jean-Louis Nahon
- UMR7275, Institut de Pharmacologie Moléculaire et Cellulaire, Centre National de la Recherche Scientifique, Valbonne, France
- University of Nice Sophia Antipolis, Nice, France
- Station de Primatologie, UPS 846, Centre National de la Recherche Scientifique, Rousset sur Arc, France
- *Correspondence: Jean-Louis Nahon, UMR7275, Institut de Pharmacologie Moléculaire et Cellulaire, Centre National de la Recherche Scientifique, 660 Route des Lucioles, Sophia Antipolis, Valbonne, France e-mail:
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