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Bigalke JA, Shan Z, Carter JR. Orexin, Sleep, Sympathetic Neural Activity, and Cardiovascular Function. Hypertension 2022; 79:2643-2655. [PMID: 36148653 PMCID: PMC9649879 DOI: 10.1161/hypertensionaha.122.19796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Inadequate sleep duration and quality are associated with reduced cardiovascular health and increased mortality. Experimental evidence points to the sympathetic nervous system as a key mediator in the observed relationship between poor sleep and cardiovascular dysfunction. However, brain mechanisms underpinning the impaired sympathetic function associated with poor sleep remain unclear. Recent evidence suggests the central orexin system, particularly orexins A and B and their receptors, have a key regulatory role for sleep in animal and human models. While orexin system activity has been observed to significantly impact sympathetic regulation in animals, the extension of these findings to humans has been difficult due to an inability to directly assess orexin system activity in humans. However, direct measures of sympathetic activity in populations with narcolepsy and chronic insomnia, 2 sleep disorders associated with deficient and excessive orexin neural activity, have allowed indirect assessment of the relationships between orexin, sleep, and sympathetic regulation. Further, the recent pharmaceutical development of dual orexin receptor antagonists for use in clinical insomnia populations offers an unprecedented opportunity to examine the mechanistic role of orexin in sleep and cardiovascular health in humans. The current review assesses the role of orexin in both sleep and sympathetic regulation from a translational perspective, spanning animal and human studies. The review concludes with future research directions necessary to fully elucidate the mechanistic role for orexin in sleep and sympathetic regulation in humans.
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Affiliation(s)
- Jeremy A. Bigalke
- Department of Health and Human Development, Montana State University, Bozeman, Montana
- Department of Psychology, Montana State University, Bozeman, Montana
| | - Zhiying Shan
- Department of Kinesiology and Integrative Physiology, Michigan Technological University, Houghton, Michigan
| | - Jason R. Carter
- Department of Health and Human Development, Montana State University, Bozeman, Montana
- Department of Psychology, Montana State University, Bozeman, Montana
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2
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Villano I, La Marra M, Di Maio G, Monda V, Chieffi S, Guatteo E, Messina G, Moscatelli F, Monda M, Messina A. Physiological Role of Orexinergic System for Health. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:8353. [PMID: 35886210 PMCID: PMC9323672 DOI: 10.3390/ijerph19148353] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 07/03/2022] [Accepted: 07/05/2022] [Indexed: 02/06/2023]
Abstract
Orexins, or hypocretins, are excitatory neuropeptides involved in the regulation of feeding behavior and the sleep and wakefulness states. Since their discovery, several lines of evidence have highlighted that orexin neurons regulate a great range of physiological functions, giving it the definition of a multitasking system. In the present review, we firstly describe the mechanisms underlining the orexin system and their interactions with the central nervous system (CNS). Then, the system's involvement in goal-directed behaviors, sleep/wakefulness state regulation, feeding behavior and energy homeostasis, reward system, and aging and neurodegenerative diseases are described. Advanced evidence suggests that the orexin system is crucial for regulating many physiological functions and could represent a promising target for therapeutical approaches to obesity, drug addiction, and emotional stress.
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Affiliation(s)
- Ines Villano
- Department of Experimental Medicine, University of Campania “Luigi Vanvitelli”, 80138 Naples, Italy; (M.L.M.); (G.D.M.); (S.C.); (M.M.); (A.M.)
| | - Marco La Marra
- Department of Experimental Medicine, University of Campania “Luigi Vanvitelli”, 80138 Naples, Italy; (M.L.M.); (G.D.M.); (S.C.); (M.M.); (A.M.)
| | - Girolamo Di Maio
- Department of Experimental Medicine, University of Campania “Luigi Vanvitelli”, 80138 Naples, Italy; (M.L.M.); (G.D.M.); (S.C.); (M.M.); (A.M.)
| | - Vincenzo Monda
- Department of Movement Sciences and Wellbeing, University of Naples “Parthenope”, 80138 Naples, Italy; (V.M.); (E.G.)
| | - Sergio Chieffi
- Department of Experimental Medicine, University of Campania “Luigi Vanvitelli”, 80138 Naples, Italy; (M.L.M.); (G.D.M.); (S.C.); (M.M.); (A.M.)
| | - Ezia Guatteo
- Department of Movement Sciences and Wellbeing, University of Naples “Parthenope”, 80138 Naples, Italy; (V.M.); (E.G.)
| | - Giovanni Messina
- Department of Clinical and Experimental Medicine, University of Foggia, 71100 Foggia, Italy; (G.M.); (F.M.)
| | - Fiorenzo Moscatelli
- Department of Clinical and Experimental Medicine, University of Foggia, 71100 Foggia, Italy; (G.M.); (F.M.)
| | - Marcellino Monda
- Department of Experimental Medicine, University of Campania “Luigi Vanvitelli”, 80138 Naples, Italy; (M.L.M.); (G.D.M.); (S.C.); (M.M.); (A.M.)
| | - Antonietta Messina
- Department of Experimental Medicine, University of Campania “Luigi Vanvitelli”, 80138 Naples, Italy; (M.L.M.); (G.D.M.); (S.C.); (M.M.); (A.M.)
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Kaplan GB, Lakis GA, Zhoba H. Sleep-Wake and Arousal Dysfunctions in Post-Traumatic Stress Disorder:Role of Orexin Systems. Brain Res Bull 2022; 186:106-122. [PMID: 35618150 DOI: 10.1016/j.brainresbull.2022.05.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 04/20/2022] [Accepted: 05/10/2022] [Indexed: 12/15/2022]
Abstract
Post-traumatic stress disorder (PTSD) is a trauma-related condition that produces distressing fear memory intrusions, avoidance behaviors, hyperarousal/startle, stress responses and insomnia. This review focuses on the importance of the orexin neural system as a novel mechanism related to the pathophysiology of PTSD. Orexinergic neurons originate in the lateral hypothalamus and project widely to key neurotransmitter system neurons, autonomic neurons, the hypothalamic-pituitaryadrenal (HPA) axis, and fear-related neural circuits. After trauma or stress, the basolateral amygdala (BLA) transmits sensory information to the central nucleus of the amygdala (CeA) and in turn to the hypothalamus and other subcortical and brainstem regions to promote fear and threat. Orexin receptors have a prominent role in this circuit as fear conditioned orexin receptor knockout mice show decreased fear expression while dual orexin receptor antagonists (DORAs) inhibit fear acquisition and expression. Orexin activation of an infralimbic-amygdala circuit impedes fear extinction while DORA treatments enhance it. Increased orexin signaling to the amygdalocortical- hippocampal circuit promotes avoidance behaviors. Orexin has an important role in activating sympathetic nervous system (SNS) activity and the HPA axis stress responses. Blockade of orexin receptors reduces fear-conditioned startle responses. In PTSD models, individuals demonstrate sleep disturbances such as increased sleep latency and more transitions to wakefulness. Increased orexin activity impairs sleep by promoting wakefulness and reducing total sleep time while DORA treatments enhance sleep onset and maintenance. The orexinergic neural system provides important mechanisms for understanding multiple PTSD behaviors and provides new medication targets to treat this often persistent and debilitating illness.
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Affiliation(s)
- Gary B Kaplan
- Mental Health Service, VA Boston Healthcare System, West Roxbury, MA, 02132 USA; Department of Psychiatry, Boston University School of Medicine, Boston, MA, 02118 USA; Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Boston, MA, 02118 USA.
| | - Gabrielle A Lakis
- Research Service, VA Boston Healthcare System, West Roxbury, MA, 02132 USA; Undergraduate Program in Neuroscience, Boston University, Boston, MA, 02215 USA
| | - Hryhoriy Zhoba
- Research Service, VA Boston Healthcare System, West Roxbury, MA, 02132 USA
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4
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Roles of Neuropeptides in Sleep-Wake Regulation. Int J Mol Sci 2022; 23:ijms23094599. [PMID: 35562990 PMCID: PMC9103574 DOI: 10.3390/ijms23094599] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Revised: 03/31/2022] [Accepted: 04/19/2022] [Indexed: 12/04/2022] Open
Abstract
Sleep and wakefulness are basic behavioral states that require coordination between several brain regions, and they involve multiple neurochemical systems, including neuropeptides. Neuropeptides are a group of peptides produced by neurons and neuroendocrine cells of the central nervous system. Like traditional neurotransmitters, neuropeptides can bind to specific surface receptors and subsequently regulate neuronal activities. For example, orexin is a crucial component for the maintenance of wakefulness and the suppression of rapid eye movement (REM) sleep. In addition to orexin, melanin-concentrating hormone, and galanin may promote REM sleep. These results suggest that neuropeptides play an important role in sleep–wake regulation. These neuropeptides can be divided into three categories according to their effects on sleep–wake behaviors in rodents and humans. (i) Galanin, melanin-concentrating hormone, and vasoactive intestinal polypeptide are sleep-promoting peptides. It is also noticeable that vasoactive intestinal polypeptide particularly increases REM sleep. (ii) Orexin and neuropeptide S have been shown to induce wakefulness. (iii) Neuropeptide Y and substance P may have a bidirectional function as they can produce both arousal and sleep-inducing effects. This review will introduce the distribution of various neuropeptides in the brain and summarize the roles of different neuropeptides in sleep–wake regulation. We aim to lay the foundation for future studies to uncover the mechanisms that underlie the initiation, maintenance, and end of sleep–wake states.
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Levine AS, Jewett DC, Kotz CM, Olszewski PK. Behavioral plasticity: Role of neuropeptides in shaping feeding responses. Appetite 2022; 174:106031. [PMID: 35395362 DOI: 10.1016/j.appet.2022.106031] [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: 12/19/2021] [Revised: 03/12/2022] [Accepted: 03/29/2022] [Indexed: 11/28/2022]
Abstract
Behavioral plasticity refers to changes occurring due to external influences on an organism, including adaptation, learning, memory and enduring influences from early life experience. There are 2 types of behavioral plasticity: "developmental", which refers to gene/environment interactions affecting a phenotype, and "activational" which refers to innate physiology and can involve structural physiological changes of the body. In this review, we focus on feeding behavior, and studies involving neuropeptides that influence behavioral plasticity - primarily opioids, orexin, neuropeptide Y, and oxytocin. In each section of the review, we include examples of behavioral plasticity as it relates to actions of these neuropeptides. It can be concluded from this review that eating behavior is influenced by a number of external factors, including time of day, type of food available, energy balance state, and stressors. The reviewed work underscores that environmental factors play a critical role in feeding behavior and energy balance, but changes in eating behavior also result from a multitude of non-environmental factors, such that there can be no single mechanism or variable that can explain ingestive behavior.
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Affiliation(s)
- Allen S Levine
- Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN, 55113, USA.
| | - David C Jewett
- Department of Psychology, University of Wisconsin-Eau Claire, Eau Claire, WI, USA
| | - Catherine M Kotz
- Department of Integrative Biology and Physiology, Medical School, University of Minnesota, Minneapolis, MN, 55414, USA; Geriatric, Research, Education and Clinical Center, Minneapolis Veterans Affairs Health, Minneapolis, MN, 55417, USA
| | - Pawel K Olszewski
- Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN, 55113, USA; Department of Integrative Biology and Physiology, Medical School, University of Minnesota, Minneapolis, MN, 55414, USA; Faculty of Science and Engineering, University of Waikato, Hamilton, 3240, New Zealand
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Arrigoni E, Fuller PM. The Role of the Central Histaminergic System in Behavioral State Control. Curr Top Behav Neurosci 2022; 59:447-468. [PMID: 34595740 DOI: 10.1007/7854_2021_263] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Histamine is a small monoamine signaling molecule that plays a role in many peripheral and central physiological processes, including the regulation of wakefulness. The tuberomammillary nucleus is the sole neuronal source of histamine in the brain, and histamine neurons are thought to promote wakefulness and vigilance maintenance - under certain environmental and/or behavioral contexts - through their diffuse innervation of the cortex and other wake-promoting brain circuits. Histamine neurons also contain a number of other putative neurotransmitters, although the functional role of these co-transmitters remains incompletely understood. Within the brain histamine operates through three receptor subtypes that are located on pre- and post-synaptic membranes. Some histamine receptors exhibit constitutive activity, and hence exist in an activated state even in the absence of histamine. Newer medications used to reduce sleepiness in narcolepsy patients in fact enhance histamine signaling by blunting the constitutive activity of these histamine receptors. In this chapter, we provide an overview of the central histamine system with an emphasis on its role in behavioral state regulation and how drugs targeting histamine receptors are used clinically to treat a wide range of sleep-wake disorders.
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Affiliation(s)
- Elda Arrigoni
- Department of Neurology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA.
| | - Patrick M Fuller
- Department of Neurological Surgery, University of California Davis School of Medicine, Davis, CA, USA
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Coleman P, de Lecea L, Gotter A, Hagan J, Hoyer D, Kilduff T, Kukkonen JP, Porter R, Renger J, Siegel JM, Sutcliffe G, Upton N, Winrow CJ. Orexin receptors in GtoPdb v.2021.3. IUPHAR/BPS GUIDE TO PHARMACOLOGY CITE 2021; 2021. [PMID: 34927075 DOI: 10.2218/gtopdb/f51/2021.3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Orexin receptors (nomenclature as agreed by the NC-IUPHAR Subcommittee on Orexin receptors [42]) are activated by the endogenous polypeptides orexin-A and orexin-B (also known as hypocretin-1 and -2; 33 and 28 aa) derived from a common precursor, preproorexin or orexin precursor, by proteolytic cleavage and some typical peptide modifications [109]. Currently the only orexin receptor ligands in clinical use are suvorexant and lemborexant, which are used as hypnotics. Orexin receptor crystal structures have been solved [134, 133, 54, 117, 46].
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GABAergic Neurons in the Dorsal-Intermediate Lateral Septum Regulate Sleep-Wakefulness and Anesthesia in Mice. Anesthesiology 2021; 135:463-481. [PMID: 34259824 DOI: 10.1097/aln.0000000000003868] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
BACKGROUND The γ-aminobutyric acid-mediated (GABAergic) inhibitory system in the brain is critical for regulation of sleep-wake and general anesthesia. The lateral septum contains mainly GABAergic neurons, being cytoarchitectonically divided into the dorsal, intermediate, and ventral parts. This study hypothesized that GABAergic neurons of the lateral septum participate in the control of wakefulness and promote recovery from anesthesia. METHODS By employing fiber photometry, chemogenetic and optogenetic neuronal manipulations, anterograde tracing, in vivo electrophysiology, and electroencephalogram/electromyography recordings in adult male mice, the authors measured the role of lateral septum GABAergic neurons to the control of sleep-wake transition and anesthesia emergence and the corresponding neuron circuits in arousal and emergence control. RESULTS The GABAergic neurons of the lateral septum exhibited high activities during the awake state by in vivo fiber photometry recordings (awake vs. non-rapid eye movement sleep: 3.3 ± 1.4% vs. -1.3 ± 1.2%, P < 0.001, n = 7 mice/group; awake vs. anesthesia: 2.6 ± 1.2% vs. -1.3 ± 0.8%, P < 0.001, n = 7 mice/group). Using chemogenetic stimulation of lateral septum GABAergic neurons resulted in a 100.5% increase in wakefulness and a 51.2% reduction in non-rapid eye movement sleep. Optogenetic activation of these GABAergic neurons promoted wakefulness from sleep (median [25th, 75th percentiles]: 153.0 [115.9, 179.7] s to 4.0 [3.4, 4.6] s, P = 0.009, n = 5 mice/group) and accelerated emergence from isoflurane anesthesia (514.4 ± 122.2 s vs. 226.5 ± 53.3 s, P < 0.001, n = 8 mice/group). Furthermore, the authors demonstrated that the lateral septum GABAergic neurons send 70.7% (228 of 323 cells) of monosynaptic projections to the ventral tegmental area GABAergic neurons, preferentially inhibiting their activities and thus regulating wakefulness and isoflurane anesthesia depth. CONCLUSIONS The results uncover a fundamental role of the lateral septum GABAergic neurons and their circuit in maintaining awake state and promoting general anesthesia emergence time. EDITOR’S PERSPECTIVE
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Ahmadi-Soleimani SM, Mianbandi V, Azizi H, Azhdari-Zarmehri H, Ghaemi-Jandabi M, Abbasi-Mazar A, Mohajer Y, Darana SP. Coregulation of sleep-pain physiological interplay by orexin system: An unprecedented review. Behav Brain Res 2020; 391:112650. [DOI: 10.1016/j.bbr.2020.112650] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 02/28/2020] [Accepted: 04/08/2020] [Indexed: 12/14/2022]
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10
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Li SB, de Lecea L. The hypocretin (orexin) system: from a neural circuitry perspective. Neuropharmacology 2020; 167:107993. [PMID: 32135427 DOI: 10.1016/j.neuropharm.2020.107993] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 01/23/2020] [Accepted: 02/05/2020] [Indexed: 12/11/2022]
Abstract
Hypocretin/orexin neurons are distributed restrictively in the hypothalamus, a brain region known to orchestrate diverse functions including sleep, reward processing, food intake, thermogenesis, and mood. Since the hypocretins/orexins were discovered more than two decades ago, extensive studies have accumulated concrete evidence showing the pivotal role of hypocretin/orexin in diverse neural modulation. New method of viral-mediated tracing system offers the possibility to map the monosynaptic inputs and detailed anatomical connectivity of Hcrt neurons. With the development of powerful research techniques including optogenetics, fiber-photometry, cell-type/pathway specific manipulation and neuronal activity monitoring, as well as single-cell RNA sequencing, the details of how hypocretinergic system execute functional modulation of various behaviors are coming to light. In this review, we focus on the function of neural pathways from hypocretin neurons to target brain regions. Anatomical and functional inputs to hypocretin neurons are also discussed. We further briefly summarize the development of pharmaceutical compounds targeting hypocretin signaling. This article is part of the special issue on Neuropeptides.
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Affiliation(s)
- Shi-Bin Li
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, 1201 Welch Road, Stanford, CA, 94305, USA.
| | - Luis de Lecea
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, 1201 Welch Road, Stanford, CA, 94305, USA.
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Romanov RA, Alpár A, Hökfelt T, Harkany T. Unified Classification of Molecular, Network, and Endocrine Features of Hypothalamic Neurons. Annu Rev Neurosci 2019; 42:1-26. [DOI: 10.1146/annurev-neuro-070918-050414] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Peripheral endocrine output relies on either direct or feed-forward multi-order command from the hypothalamus. Efficient coding of endocrine responses is made possible by the many neuronal cell types that coexist in intercalated hypothalamic nuclei and communicate through extensive synaptic connectivity. Although general anatomical and neurochemical features of hypothalamic neurons were described during the past decades, they have yet to be reconciled with recently discovered molecular classifiers and neurogenetic function determination. By interrogating magnocellular as well as parvocellular dopamine, GABA, glutamate, and phenotypically mixed neurons, we integrate available information at the molecular, cellular, network, and endocrine output levels to propose a framework for the comprehensive classification of hypothalamic neurons. Simultaneously, we single out putative neuronal subclasses for which future research can fill in existing gaps of knowledge to rationalize cellular diversity through function-determinant molecular marks in the hypothalamus.
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Affiliation(s)
- Roman A. Romanov
- Department of Molecular Neurosciences, Center for Brain Research, Medical University of Vienna, 1090 Vienna, Austria
| | - Alán Alpár
- Department of Anatomy, Histology, and Embryology, and SE NAP Research Group of Experimental Neuroanatomy and Developmental Biology, Semmelweis University, H-1085 Budapest, Hungary
| | - Tomas Hökfelt
- Department of Neuroscience, Biomedicum, Karolinska Institutet, SE-17165 Stockholm, Sweden
| | - Tibor Harkany
- Department of Molecular Neurosciences, Center for Brain Research, Medical University of Vienna, 1090 Vienna, Austria
- Department of Neuroscience, Biomedicum, Karolinska Institutet, SE-17165 Stockholm, Sweden
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12
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Sepúlveda PO, Tapia LF, Monsalves S. Neural inertia and differences between loss of and recovery from consciousness during total intravenous anaesthesia: a narrative review. Anaesthesia 2019; 74:801-809. [DOI: 10.1111/anae.14609] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/21/2019] [Indexed: 12/31/2022]
Affiliation(s)
- P. O. Sepúlveda
- Department of Anaesthesia and Pain Clínica Alemana Santiago de Chile Chile
- Department of Anaesthesia , Universidad del Desarrollo Santiago de Chile Chile
| | - L. F. Tapia
- Consultant, Department of Anaesthesia and Pain Clínica Alemana Santiago de Chile Chile
| | - S. Monsalves
- Consultant, Department of Anaesthesia and Pain Clínica Alemana Santiago de Chile Chile
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Hypocretin and the Regulation of Sleep-Wake Transitions. ACTA ACUST UNITED AC 2019. [DOI: 10.1016/b978-0-12-813743-7.00006-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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14
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Activation of orexin system facilitates anesthesia emergence and pain control. Proc Natl Acad Sci U S A 2018; 115:E10740-E10747. [PMID: 30348769 DOI: 10.1073/pnas.1808622115] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Orexin (also known as hypocretin) neurons in the hypothalamus play an essential role in sleep-wake control, feeding, reward, and energy homeostasis. The likelihood of anesthesia and sleep sharing common pathways notwithstanding, it is important to understand the processes underlying emergence from anesthesia. In this study, we investigated the role of the orexin system in anesthesia emergence, by specifically activating orexin neurons utilizing the designer receptors exclusively activated by designer drugs (DREADD) chemogenetic approach. With injection of adeno-associated virus into the orexin-Cre transgenic mouse brain, we expressed the DREADD receptor hM3Dq specifically in orexin neurons and applied the hM3Dq ligand clozapine to activate orexin neurons. We monitored orexin neuronal activities by c-Fos staining and whole-cell patch-clamp recording and examined the consequence of orexin neuronal activation via EEG recording. Our results revealed that the orexin-DREADD mice with activated orexin neurons emerged from anesthesia with significantly shorter latency than the control mice. As an indication of reduced pain sensitivity, these orexin-DREADD mice took longer to respond to the 55 °C thermal stimuli in the hot plate test and exhibited significantly less frequent licking of the formalin-injected paw in the formalin test. Our study suggests that approaches to activate the orexin system can be beneficial in postoperative recovery.
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Cascella M, Bimonte S, Muzio MR. Towards a better understanding of anesthesia emergence mechanisms: Research and clinical implications. World J Methodol 2018; 8:9-16. [PMID: 30345225 PMCID: PMC6189114 DOI: 10.5662/wjm.v8.i2.9] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 08/09/2018] [Accepted: 08/26/2018] [Indexed: 02/06/2023] Open
Abstract
Emergence from anesthesia (AE) is the ending stage of anesthesia featuring the transition from unconsciousness to complete wakefulness and recovery of consciousness (RoC). A wide range of undesirable complications, including coughing, respiratory/cardiovascular events, and mental status changes such as emergence delirium, and delayed RoC, may occur during this critical phase. In general anesthesia processes, induction and AE represent a neurobiological example of “hysteresis”. Indeed, AE mechanisms should not be simply considered as reverse events of those occurring in the induction phase. Anesthesia-induced loss of consciousness (LoC) and AE until RoC are quite distinct phenomena with, in part, a distinct neurobiology. Althoughanaesthetics produce LoC mostly by affecting cortical connectivity, arousal processes at the end of anesthesia are triggered by structures deep in the brain, rather than being induced within the neocortex. This work aimed to provide an overview on AE processes research, in terms of mechanisms, and EEG findings. Because most of the research in this field concerns preclinical investigations, translational suggestions and research perspectives are proposed. However, little is known about the relationship between AE neurobiology, and potential complications occurring during the emergence, and after the RoC. Thus, another scope of this review is to underline why a better understanding of AE mechanisms could have significant clinical implications, such as improving the patients’ quality of recovery, and avoiding early and late postoperative complications.
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Affiliation(s)
- Marco Cascella
- Division of Anesthesia and Pain Management, Department of Supportive Care, Istituto Nazionale Tumori “Fondazione G. Pascale” - IRCSS, Naples 80131, Italy
| | - Sabrina Bimonte
- Division of Anesthesia and Pain Management, Department of Supportive Care, Istituto Nazionale Tumori “Fondazione G. Pascale” - IRCSS, Naples 80131, Italy
| | - Maria Rosaria Muzio
- Division of Infantile Neuropsychiatry, UOMI-Maternal and Infant Health, ASL NA3 SUD Torre del Greco, Naples 80059, Italy
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16
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Nevárez N, de Lecea L. Recent advances in understanding the roles of hypocretin/orexin in arousal, affect, and motivation. F1000Res 2018; 7. [PMID: 30254737 PMCID: PMC6127742 DOI: 10.12688/f1000research.15097.1] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 08/24/2018] [Indexed: 12/11/2022] Open
Abstract
The hypocretins (Hcrts) are two alternatively spliced neuropeptides (Hcrt1/Ox-A and Hcrt2/Ox-B) that are synthesized exclusively in the hypothalamus. Data collected in the 20 years since their discovery have supported the view that the Hcrts play a broad role in the control of arousal with a particularly important role in the maintenance of wakefulness and sleep-to-wake transitions. While this latter point has received an overwhelming amount of research attention, a growing literature has begun to broaden our understanding of the many diverse roles that the Hcrts play in physiology and behavior. Here, we review recent advances in the neurobiology of Hcrt in three sections. We begin by surveying findings on Hcrt function within normal sleep/wake states as well as situations of aberrant sleep (that is, narcolepsy). In the second section, we discuss research establishing a role for Hcrt in mood and affect (that is, anxiety, stress, and motivation). Finally, in the third section, we briefly discuss future directions for the field and place an emphasis on analytical modeling of Hcrt neural activity. We hope that the data discussed here provide a broad overview of recent progress in the field and make clear the diversity of roles played by these neuromodulators.
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Affiliation(s)
- Natalie Nevárez
- Department of Psychiatry & Behavioral Sciences, Stanford University, Stanford, California, USA
| | - Luis de Lecea
- Department of Psychiatry & Behavioral Sciences, Stanford University, Stanford, California, USA
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Tyree SM, Borniger JC, de Lecea L. Hypocretin as a Hub for Arousal and Motivation. Front Neurol 2018; 9:413. [PMID: 29928253 PMCID: PMC5997825 DOI: 10.3389/fneur.2018.00413] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Accepted: 05/18/2018] [Indexed: 01/01/2023] Open
Abstract
The lateral hypothalamus is comprised of a heterogeneous mix of neurons that serve to integrate and regulate sleep, feeding, stress, energy balance, reward, and motivated behavior. Within these populations, the hypocretin/orexin neurons are among the most well studied. Here, we provide an overview on how these neurons act as a central hub integrating sensory and physiological information to tune arousal and motivated behavior accordingly. We give special attention to their role in sleep-wake states and conditions of hyper-arousal, as is the case with stress-induced anxiety. We further discuss their roles in feeding, drug-seeking, and sexual behavior, which are all dependent on the motivational state of the animal. We further emphasize the application of powerful techniques, such as optogenetics, chemogenetics, and fiber photometry, to delineate the role these neurons play in lateral hypothalamic functions.
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Affiliation(s)
- Susan M Tyree
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, United States
| | - Jeremy C Borniger
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, United States
| | - Luis de Lecea
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, United States
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18
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Messina A, Monda M, Valenzano A, Messina G, Villano I, Moscatelli F, Cibelli G, Marsala G, Polito R, Ruberto M, Carotenuto M, Monda V, Viggiano A, Daniele A, Nigro E. Functional Changes Induced by Orexin A and Adiponectin on the Sympathetic/Parasympathetic Balance. Front Physiol 2018; 9:259. [PMID: 29623046 PMCID: PMC5874516 DOI: 10.3389/fphys.2018.00259] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2017] [Accepted: 03/06/2018] [Indexed: 12/20/2022] Open
Abstract
Obesity and lifestyle-related diseases are major problems faced by people in developed nations. Although exercise training prevents the progression of diabetes and obesity, the motivation for exercise is generally low in obese animals and humans. The autonomic nervous system (SNA) plays a crucial role in the regulation of eating behavior. Moreover, the SNA is involved in the body temperature regulation that is strictly related to body weight control, in accordance with the “thermoregulatory hypothesis” of food intake. Some neuronal peptides and hormones, like orexins and adiponectin, are also involved in the regulation of locomotion activity as well as food intake and metabolic rate. Furthermore, adiponectin as well as orexin A are involved in the control of body temperature, food intake and therefore in obesity-related diseases. The aim of this study was to investigate the changes in body temperature (Tc), and heart rate (HR) after an intracerebroventricular (ICV) injection of orexin A and adiponectin in animal model. The results of this study show that the orexin A levels are likely involved in the increase of Tc and HR. It is also clear that there is not a correlation between these parameters and adiponectin levels. Further studies are needed to assess adiponectin actions and outcome in the central nervous system in terms of energy expenditure, body temperature, heart rate and physical activity performance regulation.
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Affiliation(s)
- Antonietta Messina
- Department of Experimental Medicine, University of Campania "Luigi Vanvitelli,"Naples, Italy
| | - Marcellino Monda
- Department of Experimental Medicine, University of Campania "Luigi Vanvitelli,"Naples, Italy
| | - Anna Valenzano
- Department of Clinical and Experimental Medicine, University of Foggia, Foggia, Italy
| | - Giovanni Messina
- Department of Clinical and Experimental Medicine, University of Foggia, Foggia, Italy
| | - Ines Villano
- Department of Experimental Medicine, University of Campania "Luigi Vanvitelli,"Naples, Italy
| | - Fiorenzo Moscatelli
- Department of Clinical and Experimental Medicine, University of Foggia, Foggia, Italy
| | - Giuseppe Cibelli
- Department of Clinical and Experimental Medicine, University of Foggia, Foggia, Italy
| | - Gabriella Marsala
- Struttura Complessa di Farmacia, Azienda Ospedaliero-Universitaria, Foggia, Italy
| | - Rita Polito
- CEINGE-Biotecnologie Avanzate Scarl, Naples, Italy
| | - Maria Ruberto
- Department of Mental Health, Physical and Preventive Medicine, Clinic of Child and Adolescent Neuropsychiatry, Università degli Studi della Campania "Luigi Vanvitelli,"Naples, Italy
| | - Marco Carotenuto
- Clinic of Child and Adolescent Neuropsychiatry, Center for Childhood Headache, Department of Mental Health, Physical and Preventive Medicine, University of Campania "Luigi Vanvitelli,"Naples, Italy
| | - Vincenzo Monda
- Department of Experimental Medicine, University of Campania "Luigi Vanvitelli,"Naples, Italy
| | - Andrea Viggiano
- Department of Medicine and Surgery, University of Salerno, Baronissi, Italy
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Abstract
Achieving a smooth and rapid emergence from general anesthesia is of particular importance for neurosurgical patients and is a clinical goal for neuroanesthesiologists. Recent data suggest that the process of emergence is not simply the mirror image of induction, but rather controlled by distinct neural circuits. In this narrative review, we discuss (1) hysteresis, (2) the concept of neural inertia, (3) the asymmetry between the neurobiology of induction and emergence, and (4) recent attempts at actively inducing emergence.
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Hypothalamic Tuberomammillary Nucleus Neurons: Electrophysiological Diversity and Essential Role in Arousal Stability. J Neurosci 2017; 37:9574-9592. [PMID: 28874450 DOI: 10.1523/jneurosci.0580-17.2017] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 08/10/2017] [Accepted: 08/19/2017] [Indexed: 11/21/2022] Open
Abstract
Histaminergic (HA) neurons, found in the posterior hypothalamic tuberomammillary nucleus (TMN), extend fibers throughout the brain and exert modulatory influence over numerous physiological systems. Multiple lines of evidence suggest that the activity of HA neurons is important in the regulation of vigilance despite the lack of direct, causal evidence demonstrating its requirement for the maintenance of arousal during wakefulness. Given the strong correlation between HA neuron excitability and behavioral arousal, we investigated both the electrophysiological diversity of HA neurons in brain slices and the effect of their acute silencing in vivo in male mice. For this purpose, we first validated a transgenic mouse line expressing cre recombinase in histidine decarboxylase-expressing neurons (Hdc-Cre) followed by a systematic census of the membrane properties of both HA and non-HA neurons in the ventral TMN (TMNv) region. Through unsupervised hierarchical cluster analysis, we found electrophysiological diversity both between TMNv HA and non-HA neurons, and among HA neurons. To directly determine the impact of acute cessation of HA neuron activity on sleep-wake states in awake and behaving mice, we examined the effects of optogenetic silencing of TMNv HA neurons in vivo We found that acute silencing of HA neurons during wakefulness promotes slow-wave sleep, but not rapid eye movement sleep, during a period of low sleep pressure. Together, these data suggest that the tonic firing of HA neurons is necessary for the maintenance of wakefulness, and their silencing not only impairs arousal but is sufficient to rapidly and selectively induce slow-wave sleep.SIGNIFICANCE STATEMENT The function of monoaminergic systems and circuits that regulate sleep and wakefulness is often disrupted as part of the pathophysiology of many neuropsychiatric disorders. One such circuit is the posterior hypothalamic histamine (HA) system, implicated in supporting wakefulness and higher brain function, but has been difficult to selectively manipulate owing to cellular heterogeneity in this region. Here we use a transgenic mouse to interrogate both the characteristic firing properties of HA neurons and their specific role in maintaining wakefulness. Our results demonstrate that the acute, cell type-specific silencing of HA neurons during wakefulness is sufficient to not only impair arousal but to rapidly and selectively induce slow-wave sleep. This work furthers our understanding of HA-mediated mechanisms that regulate behavioral arousal.
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21
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de Biase S, Nilo A, Gigli GL, Valente M. Investigational therapies for the treatment of narcolepsy. Expert Opin Investig Drugs 2017; 26:953-963. [PMID: 28726523 DOI: 10.1080/13543784.2017.1356819] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
INTRODUCTION Narcolepsy is a chronic sleep disorder characterized by a pentad of excessive daytime sleepiness (EDS), cataplexy, sleep paralysis, hypnagogic/hypnopompic hallucinations, and disturbed nocturnal sleep. While non-pharmacological treatments are sometimes helpful, more than 90% of narcoleptic patients require a pharmacological treatment. Areas covered: The present review is based on an extensive Internet and PubMed search from 1994 to 2017. It is focused on drugs currently in development for the treatment of narcolepsy. Expert opinion: Currently there is no cure for narcolepsy, with treatment focusing on symptoms control. However, these symptomatic treatments are often unsatisfactory. The research is leading to a better understanding of narcolepsy and its symptoms. New classes of compounds with possible applications in the development of novel stimulant/anticataplectic medications are described. H3 receptor antagonists represent a new therapeutic option for EDS in narcolepsy. JZP-110, with its distinct mechanism of action, would be a new therapeutic option for the treatment of EDS in the coming years. In the future, hypocretin-based therapies and immune-based therapies, could modify the clinical course of the disease. However, more information would be necessary to completely understand the autoimmune process and also how this process can be altered for therapeutic benefits.
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Affiliation(s)
- Stefano de Biase
- a Neurology Unit, Department of Experimental and Clinical Medical Sciences , University of Udine Medical School , Udine , Italy
| | - Annacarmen Nilo
- a Neurology Unit, Department of Experimental and Clinical Medical Sciences , University of Udine Medical School , Udine , Italy
| | - Gian Luigi Gigli
- a Neurology Unit, Department of Experimental and Clinical Medical Sciences , University of Udine Medical School , Udine , Italy.,b Department of Neurosciences , "S. Maria della Misericordia" University Hospital Udine , Udine , Italy
| | - Mariarosaria Valente
- a Neurology Unit, Department of Experimental and Clinical Medical Sciences , University of Udine Medical School , Udine , Italy.,b Department of Neurosciences , "S. Maria della Misericordia" University Hospital Udine , Udine , Italy
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22
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Bonaventure P, Dugovic C, Shireman B, Preville C, Yun S, Lord B, Nepomuceno D, Wennerholm M, Lovenberg T, Carruthers N, Fitz SD, Shekhar A, Johnson PL. Evaluation of JNJ-54717793 a Novel Brain Penetrant Selective Orexin 1 Receptor Antagonist in Two Rat Models of Panic Attack Provocation. Front Pharmacol 2017; 8:357. [PMID: 28649201 PMCID: PMC5465257 DOI: 10.3389/fphar.2017.00357] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Accepted: 05/24/2017] [Indexed: 11/13/2022] Open
Abstract
Orexin neurons originating in the perifornical and lateral hypothalamic area are highly reactive to anxiogenic stimuli and have strong projections to anxiety and panic-associated circuitry. Recent studies support a role for the orexin system and in particular the orexin 1 receptor (OX1R) in coordinating an integrative stress response. However, no selective OX1R antagonist has been systematically tested in two preclinical models of using panicogenic stimuli that induce panic attack in the majority of people with panic disorder, namely an acute hypercapnia-panic provocation model and a model involving chronic inhibition of GABA synthesis in the perifornical hypothalamic area followed by intravenous sodium lactate infusion. Here we report on a novel brain penetrant, selective and high affinity OX1R antagonist JNJ-54717793 (1S,2R,4R)-7-([(3-fluoro-2-pyrimidin-2-ylphenyl)carbonyl]-N-[5-(trifluoromethyl)pyrazin-2-yl]-7-azabicyclo[2.2.1]heptan-2-amine). JNJ-54717793 is a high affinity/potent OX1R antagonist and has an excellent selectivity profile including 50 fold versus the OX2R. Ex vivo receptor binding studies demonstrated that after oral administration JNJ-54717793 crossed the blood brain barrier and occupied OX1Rs in the rat brain. While JNJ-54717793 had minimal effect on spontaneous sleep in rats and in wild-type mice, its administration in OX2R knockout mice, selectively promoted rapid eye movement sleep, demonstrating target engagement and specific OX1R blockade. JNJ-54717793 attenuated CO2 and sodium lactate induced panic-like behaviors and cardiovascular responses without altering baseline locomotor or autonomic activity. These data confirm that selective OX1R antagonism may represent a novel approach of treating anxiety disorders, with no apparent sedative effects.
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Affiliation(s)
| | | | - Brock Shireman
- Janssen Research & Development, LLC, San DiegoCA, United States
| | - Cathy Preville
- Janssen Research & Development, LLC, San DiegoCA, United States
| | - Sujin Yun
- Janssen Research & Development, LLC, San DiegoCA, United States
| | - Brian Lord
- Janssen Research & Development, LLC, San DiegoCA, United States
| | | | | | | | | | - Stephanie D. Fitz
- Department of Psychiatry, Indiana University School of Medicine, IndianapolisIN, United States
| | - Anantha Shekhar
- Department of Psychiatry, Indiana University School of Medicine, IndianapolisIN, United States
- Stark Neurosciences Research Institute, Indiana University School of Medicine, IndianapolisIN, United States
| | - Philip L. Johnson
- Stark Neurosciences Research Institute, Indiana University School of Medicine, IndianapolisIN, United States
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, IndianapolisIN, United States
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Posterior hypothalamus glutamate infusion decreases pentylenetetrazol-induced seizures of male rats through hippocampal histamine increase. Pharmacol Biochem Behav 2017; 158:7-13. [PMID: 28495313 DOI: 10.1016/j.pbb.2017.05.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 05/05/2017] [Accepted: 05/06/2017] [Indexed: 11/22/2022]
Abstract
OBJECTIVES Seizures are epileptic manifestations that are intrinsically modulated through different neurotransmitters and receptor systems. Although glutamate increases excitation and hence seizures, it activates other systems which could potentially terminate seizures. Histamine originates from neurons of the posterior hypothalamus (PH) and can mediate anticonvulsant properties, but the effect of local PH glutamate on hippocampal histamine content is unknown. Therefore, in this study, the effect of PH glutamate and the involvement of hippocampal histamine in pentylenetetrazol (PTZ) induced seizure activity was studied. MATERIALS AND METHODS OX2R antagonist (TCS OX2 29, 40nmol/1μl, intra-PH), AMPA/Kainate receptor antagonist (CNQX, 3mM, intra-PH) and glutamate (1mM) were injected bilaterally into PH using stereotaxic surgery. The intravenous PTZ infusion model was used to generate behavioral convulsions and the amount of hippocampal histamine content was then measured using a biochemical method. RESULTS Administration of glutamate into PH decreased both seizure stage and the duration of tonic-clonic convulsion (TCC) with increasing TCC latency and hippocampal histamine content. Blocking OX2Rs alone or coinhibition of OX2Rs and AMPA/kainate receptors reversed these effects by increasing both seizure stage and TCC duration, and by decreasing both latency and consequent histamine content. CONCLUSIONS Our findings suggest that glutamate administration into PH may control seizures (stages and duration) through increasing the hippocampal histamine content.
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24
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Mieda M. The roles of orexins in sleep/wake regulation. Neurosci Res 2017; 118:56-65. [DOI: 10.1016/j.neures.2017.03.015] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Revised: 03/07/2017] [Accepted: 03/07/2017] [Indexed: 10/25/2022]
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25
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Genetic Analysis of Histamine Signaling in Larval Zebrafish Sleep. eNeuro 2017; 4:eN-NWR-0286-16. [PMID: 28275716 PMCID: PMC5334454 DOI: 10.1523/eneuro.0286-16.2017] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Revised: 02/07/2017] [Accepted: 02/09/2017] [Indexed: 01/11/2023] Open
Abstract
Pharmacological studies in mammals and zebrafish suggest that histamine plays an important role in promoting arousal. However, genetic studies using rodents with disrupted histamine synthesis or signaling have revealed only subtle or no sleep/wake phenotypes. Studies of histamine function in mammalian arousal are complicated by its production in cells of the immune system and its roles in humoral and cellular immunity, which can have profound effects on sleep/wake states. To avoid this potential confound, we used genetics to explore the role of histamine in regulating sleep in zebrafish, a diurnal vertebrate in which histamine production is restricted to neurons in the brain. Similar to rodent genetic studies, we found that zebrafish that lack histamine due to mutation of histidine decarboxylase (hdc) exhibit largely normal sleep/wake behaviors. Zebrafish containing predicted null mutations in several histamine receptors also lack robust sleep/wake phenotypes, although we are unable to verify that these mutants are completely nonfunctional. Consistent with some rodent studies, we found that arousal induced by overexpression of the neuropeptide hypocretin (Hcrt) or by stimulation of hcrt-expressing neurons is not blocked in hdc or hrh1 mutants. We also found that the number of hcrt-expressing or histaminergic neurons is unaffected in animals that lack histamine or Hcrt signaling, respectively. Thus, while acute pharmacological manipulation of histamine signaling has been shown to have profound effects on zebrafish and mammalian sleep, our results suggest that chronic loss of histamine signaling due to genetic mutations has only subtle effects on sleep in zebrafish, similar to rodents.
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26
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James MH, Campbell EJ, Dayas CV. Role of the Orexin/Hypocretin System in Stress-Related Psychiatric Disorders. Curr Top Behav Neurosci 2017; 33:197-219. [PMID: 28083790 DOI: 10.1007/7854_2016_56] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Orexins (hypocretins) are critically involved in coordinating appropriate physiological and behavioral responses to aversive and threatening stimuli. Acute stressors engage orexin neurons via direct projections from stress-sensitive brain regions. Orexin neurons, in turn, facilitate adaptive behavior via reciprocal connections as well as via direct projections to the hypophysiotropic neurons that coordinate the hypothalamic-pituitary-adrenal (HPA) axis response to stress. Consequently, hyperactivity of the orexin system is associated with increased motivated arousal and anxiety, and is emerging as a key feature of panic disorder. Accordingly, there has been significant interest in the therapeutic potential of pharmacological agents that antagonize orexin signaling at their receptors for the treatment of anxiety disorders. In contrast, disorders characterized by inappropriately low levels of motivated arousal, such as depression, generally appear to be associated with hypoactivity of the orexin system. This includes narcolepsy with cataplexy, a disorder characterized by the progressive loss of orexin neurons and increased rates of moderate/severe depression symptomology. Here, we provide a comprehensive overview of both clinical and preclinical evidence highlighting the role of orexin signaling in stress reactivity, as well as how perturbations to this system can result in dysregulated behavioral phenotypes.
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Affiliation(s)
- Morgan H James
- Brain Health Institute, Rutgers University/Rutgers Biomedical and Health Sciences, Piscataway, NJ, USA
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, VIC, 2337, Australia
| | - Erin J Campbell
- School of Biomedical Sciences and Pharmacy, Centre for Brain and Mental Health, University of Newcastle, Callaghan, NSW, Australia
- Hunter Medical Research Institute, 1 Kookaburra Circuit, New Lambton Heights, NSW, Australia
| | - Christopher V Dayas
- School of Biomedical Sciences and Pharmacy, Centre for Brain and Mental Health, University of Newcastle, Callaghan, NSW, Australia.
- Hunter Medical Research Institute, 1 Kookaburra Circuit, New Lambton Heights, NSW, Australia.
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Chen XY, Chen L, Du YF. Orexin-A increases the firing activity of hippocampal CA1 neurons through orexin-1 receptors. J Neurosci Res 2016; 95:1415-1426. [PMID: 27796054 DOI: 10.1002/jnr.23975] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Revised: 09/29/2016] [Accepted: 10/04/2016] [Indexed: 12/15/2022]
Affiliation(s)
- Xin-Yi Chen
- Department of Neurology; Provincial Hospital Affiliated to Shandong University; Jinan Shandong China
| | - Lei Chen
- Department of Physiology; Qingdao University; Qingdao China
| | - Yi-Feng Du
- Department of Neurology; Provincial Hospital Affiliated to Shandong University; Jinan Shandong China
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28
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The effects of unilateral lesion of the tuberomammillary nucleus E2 sub-region on nocturnal feeding and related behaviors in mice. Life Sci 2016; 162:70-6. [PMID: 27515503 DOI: 10.1016/j.lfs.2016.08.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Revised: 07/27/2016] [Accepted: 08/06/2016] [Indexed: 11/22/2022]
Abstract
AIMS Bilateral lesions of the mesencephalic trigeminal sensory nucleus (Me5), which receives histaminergic neurons from the tuberomammillary nucleus (TMN), alter nocturnal feeding and related behaviors in mice, concomitant with a decrease in orexin mRNA level in the perifornical area (PFA) during the dark phase. Therefore, we investigated the neuronal input to the TMN from the Me5, as well as the effects of TMN lesions on the circadian profiles of feeding and related behaviors. MAIN METHODS We examined the presence of neurons projecting from the Me5 to the TMN by direct injection of a retrograde tracer, Fluorogold, into the TMN E2 sub-region (TMN-E2). We also assessed feeding, drinking, and locomotion for 24h using an automated feeding behavior measurement apparatus, and analyzed the hypothalamic orexin mRNA levels in both TMN-lesion and sham-operated mice. KEY FINDINGS The presence of neuronal projections from the Me5 to the TMN-E2 was confirmed. A decrease in food and water intake and locomotion during the latter half of the dark phase was delayed in TMN-lesion but not sham-operation mice. Further, orexin mRNA expression levels were higher in both the PFA and lateral hypothalamus area (LHA) in TMN-E2-lesion mice relative to control mice, during the early half of the dark phase compared with the light phase. SIGNIFICANCE Our results suggest that histaminergic neurons in the TMN-E2 receive signals from the Me5 that modulate a switch from dark to light phase feeding and related behaviors, which in turn may be regulated by orexin neurons in the PFA and/or LHA.
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Messina A, De Fusco C, Monda V, Esposito M, Moscatelli F, Valenzano A, Carotenuto M, Viggiano E, Chieffi S, De Luca V, Cibelli G, Monda M, Messina G. Role of the Orexin System on the Hypothalamus-Pituitary-Thyroid Axis. Front Neural Circuits 2016; 10:66. [PMID: 27610076 PMCID: PMC4997012 DOI: 10.3389/fncir.2016.00066] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2016] [Accepted: 08/08/2016] [Indexed: 12/25/2022] Open
Abstract
Hypocretin/orexin (ORX) are two hypothalamic neuropeptides discovered in 1998. Since their discovery, they have been one of the most studied neuropeptide systems because of their projecting fields innervating various brain areas. The orexinergic system is tied to sleep-wakefulness cycle, and narcolepsy is a consequence of their system hypofunction. Orexinergic system is also involved in many other autonomic functions such as feeding, thermoregulation, cardiovascular and neuroendocrine regulation. The main aim of this mini review article is to investigate the relationship between ORX and thyroid system regulation. Although knowledge about the ORX system is evolving, its putative effects on hypothalamic-pituitary-thyroid (HPT) axis still appear unclear. We analyzed some studies about ORX control of HPT axis to know better the relationship between them. The studies that were analyzed suggest Hypocretin/ORX to modulate the thyroid regulation, but the nature (excitatory or inhibitory) of this possible interaction remains actually unclear and needs to be confirmed.
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Affiliation(s)
- Antonietta Messina
- Department of Experimental Medicine, Section of Human Physiology and Unit of Dietetic and Sport Medicine, Second University of Naples Naples, Italy
| | - Carolina De Fusco
- Department of Experimental Medicine, Section of Human Physiology and Unit of Dietetic and Sport Medicine, Second University of Naples Naples, Italy
| | - Vincenzo Monda
- Department of Experimental Medicine, Section of Human Physiology and Unit of Dietetic and Sport Medicine, Second University of Naples Naples, Italy
| | - Maria Esposito
- Neapolitan Brain Group (NBG), Clinic of Child and Adolescent Neuropsychiatry, Department of Mental, Physical Health and Preventive Medicine, Second University of Naples Naples, Italy
| | - Fiorenzo Moscatelli
- Department of Clinical and Experimental Medicine, University of Foggia Foggia, Italy
| | - Anna Valenzano
- Department of Clinical and Experimental Medicine, University of Foggia Foggia, Italy
| | - Marco Carotenuto
- Neapolitan Brain Group (NBG), Clinic of Child and Adolescent Neuropsychiatry, Department of Mental, Physical Health and Preventive Medicine, Second University of Naples Naples, Italy
| | - Emanuela Viggiano
- Department of Experimental Medicine, Section of Human Physiology and Unit of Dietetic and Sport Medicine, Second University of Naples Naples, Italy
| | - Sergio Chieffi
- Department of Experimental Medicine, Section of Human Physiology and Unit of Dietetic and Sport Medicine, Second University of Naples Naples, Italy
| | - Vincenzo De Luca
- Department of Psychiatry, University of Toronto Toronto, ON, Canada
| | - Giuseppe Cibelli
- Department of Clinical and Experimental Medicine, University of Foggia Foggia, Italy
| | - Marcellino Monda
- Department of Experimental Medicine, Section of Human Physiology and Unit of Dietetic and Sport Medicine, Second University of Naples Naples, Italy
| | - Giovanni Messina
- Department of Experimental Medicine, Section of Human Physiology and Unit of Dietetic and Sport Medicine, Second University of NaplesNaples, Italy; Department of Clinical and Experimental Medicine, University of FoggiaFoggia, Italy
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Zhang LN, Yang C, Ouyang PR, Zhang ZC, Ran MZ, Tong L, Dong HL, Liu Y. Orexin-A facilitates emergence of the rat from isoflurane anesthesia via mediation of the basal forebrain. Neuropeptides 2016; 58:7-14. [PMID: 26919917 DOI: 10.1016/j.npep.2016.02.003] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Revised: 02/03/2016] [Accepted: 02/03/2016] [Indexed: 12/17/2022]
Abstract
Previous studies have demonstrated that orexinergic neurons involve in promoting emergence from anesthesia of propofol, an intravenous anesthetics, while whether both of orexin-A and orexin-B have promotive action on emergence via mediation of basal forebrain (BF) in isoflurane anesthesia has not been elucidated. In this study, we observed c-Fos expressions in orexinergic neurons following isoflurane inhalation (for 0, 30, 60, and 120min) and at the time when the righting reflex returned after the cessation of anesthesia. The plasma concentrations of orexin-A and -B in anesthesia-arousal process were measured by radioimmunoassay. Orexin-A and -B (30 or 100pmol) or the orexin receptor-1 and -2 antagonist SB-334867A and TCS-OX2-29 (5 or 20μg) were microinjected into the basal forebrain respectively. The effects of them on the induction (loss of the righting reflex) and the emergence time (return of the righting reflex) under isoflurane anesthesia were observed. The results showed that the numbers of c-Fos-immunoreactive orexinergic neurons in the hypothalamus decreased over time with continued isoflurane inhalation, but restored at emergence. Similar alterations were observed in changes of plasma orexin-A concentrations but not in orexin-B during emergence. Administration of orexins had no effect on the induction time, but orexin-A facilitated the emergence of rats from isoflurane anesthesia while orexin-B didn't. Conversely, microinjection of the orexin receptor-1 antagonist SB-334867A delayed emergence from isoflurane anesthesia. The results indicate that orexin-A plays a promotive role in the emergence of isoflurane anesthesia and this effect is mediated by the basal forebrain.
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Affiliation(s)
- Li-Na Zhang
- Institute of Neurobiology, Key Laboratory of Environment and Genes Related to Diseases, Education Ministry, Xian Jiaotong University School of Medicine, China
| | - Cen Yang
- Department of Anesthesiology, Xijing Hospital, Fourth Military Medical University, China
| | - Peng-Rong Ouyang
- Department of Anesthesiology, Xijing Hospital, Fourth Military Medical University, China
| | - Zhi-Chao Zhang
- Institute of Neurobiology, Key Laboratory of Environment and Genes Related to Diseases, Education Ministry, Xian Jiaotong University School of Medicine, China
| | - Ming-Zi Ran
- Department of Anesthesiology, Xijing Hospital, Fourth Military Medical University, China
| | - Li Tong
- Department of Anesthesiology, Xijing Hospital, Fourth Military Medical University, China
| | - Hai-Long Dong
- Department of Anesthesiology, Xijing Hospital, Fourth Military Medical University, China.
| | - Yong Liu
- Institute of Neurobiology, Key Laboratory of Environment and Genes Related to Diseases, Education Ministry, Xian Jiaotong University School of Medicine, China.
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The Dual Hypocretin Receptor Antagonist Almorexant is Permissive for Activation of Wake-Promoting Systems. Neuropsychopharmacology 2016; 41:1144-55. [PMID: 26289145 PMCID: PMC4748439 DOI: 10.1038/npp.2015.256] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Revised: 07/30/2015] [Accepted: 08/11/2015] [Indexed: 01/21/2023]
Abstract
The dual hypocretin receptor (HcrtR) antagonist almorexant (ALM) may promote sleep through selective disfacilitation of wake-promoting systems, whereas benzodiazepine receptor agonists (BzRAs) such as zolpidem (ZOL) induce sleep through general inhibition of neural activity. Previous studies have indicated that HcrtR antagonists cause less-functional impairment than BzRAs. To gain insight into the mechanisms underlying these differential profiles, we compared the effects of ALM and ZOL on functional activation of wake-promoting systems at doses equipotent for sleep induction. Sprague-Dawley rats, implanted for EEG/EMG recording, were orally administered vehicle (VEH), 100 mg/kg ALM, or 100 mg/kg ZOL during their active phase and either left undisturbed or kept awake for 90 min after which their brains were collected. ZOL-treated rats required more stimulation to maintain wakefulness than VEH- or ALM-treated rats. We measured Fos co-expression with markers for wake-promoting cell groups in the lateral hypothalamus (Hcrt), tuberomammillary nuclei (histamine; HA), basal forebrain (acetylcholine; ACh), dorsal raphe (serotonin; 5HT), and singly labeled Fos(+) cells in the locus coeruleus (LC). Following SD, Fos co-expression in Hcrt, HA, and ACh neurons (but not in 5HT neurons) was consistently elevated in VEH- and ALM-treated rats, whereas Fos expression in these neuronal groups was unaffected by SD in ZOL-treated rats. Surprisingly, Fos expression in the LC was elevated in ZOL- but not in VEH- or ALM-treated SD animals. These results indicate that Hcrt signaling is unnecessary for the activation of Hcrt, HA, or ACh wake-active neurons, which may underlie the milder cognitive impairment produced by HcrtR antagonists compared to ZOL.
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Abbas MG, Shoji H, Soya S, Hondo M, Miyakawa T, Sakurai T. Comprehensive Behavioral Analysis of Male Ox1r (-/-) Mice Showed Implication of Orexin Receptor-1 in Mood, Anxiety, and Social Behavior. Front Behav Neurosci 2015; 9:324. [PMID: 26696848 PMCID: PMC4674555 DOI: 10.3389/fnbeh.2015.00324] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 11/12/2015] [Indexed: 11/13/2022] Open
Abstract
Neuropeptides orexin A and orexin B, which are exclusively produced by neurons in the lateral hypothalamic area, play an important role in the regulation of a wide range of behaviors and homeostatic processes, including regulation of sleep/wakefulness states and energy homeostasis. The orexin system has close anatomical and functional relationships with systems that regulate the autonomic nervous system, emotion, mood, the reward system, and sleep/wakefulness states. Recent pharmacological studies using selective antagonists have suggested that orexin receptor-1 (OX1R) is involved in physiological processes that regulate emotion, the reward system, and autonomic nervous system. Here, we examined Ox1r (-/-) mice with a comprehensive behavioral test battery to screen additional OX1R functions. Ox1r (-/-) mice showed increased anxiety-like behavior, altered depression-like behavior, slightly decreased spontaneous locomotor activity, reduced social interaction, increased startle response, and decreased prepulse inhibition. These results suggest that OX1R plays roles in social behavior and sensory motor gating in addition to roles in mood and anxiety.
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Affiliation(s)
- Md G Abbas
- Department of Molecular Neuroscience and Integrative Physiology, Faculty of Medicine, Kanazawa University Kanazawa, Japan
| | - Hirotaka Shoji
- Division of Systems Medical Science, Institute for Comprehensive Medical Science, Fujita Health University Toyoake, Japan
| | - Shingo Soya
- Department of Molecular Neuroscience and Integrative Physiology, Faculty of Medicine, Kanazawa University Kanazawa, Japan
| | - Mari Hondo
- Department of Molecular Neuroscience and Integrative Physiology, Faculty of Medicine, Kanazawa University Kanazawa, Japan ; International Institute for Integrative Sleep Medicine, University of Tsukuba Tsukuba, Japan
| | - Tsuyoshi Miyakawa
- Division of Systems Medical Science, Institute for Comprehensive Medical Science, Fujita Health University Toyoake, Japan ; Section of Behavior Patterns, Center for Genetic Analysis of Behavior, National Institute for Physiological Sciences Okazaki, Japan
| | - Takeshi Sakurai
- Department of Molecular Neuroscience and Integrative Physiology, Faculty of Medicine, Kanazawa University Kanazawa, Japan ; International Institute for Integrative Sleep Medicine, University of Tsukuba Tsukuba, Japan
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Abstract
Cortical electroencephalographic activity arises from corticothalamocortical interactions, modulated by wake-promoting monoaminergic and cholinergic input. These wake-promoting systems are regulated by hypothalamic hypocretin/orexins, while GABAergic sleep-promoting nuclei are found in the preoptic area, brainstem and lateral hypothalamus. Although pontine acetylcholine is critical for REM sleep, hypothalamic melanin-concentrating hormone/GABAergic cells may "gate" REM sleep. Daily sleep-wake rhythms arise from interactions between a hypothalamic circadian pacemaker and a sleep homeostat whose anatomical locus has yet to be conclusively defined. Control of sleep and wakefulness involves multiple systems, each of which presents vulnerability to sleep/wake dysfunction that may predispose to physical and/or neuropsychiatric disorders.
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Affiliation(s)
- Michael D Schwartz
- Biosciences Division, Center for Neuroscience, SRI International, 333 Ravenswood Avenue, Menlo Park, CA 94025, USA
| | - Thomas S Kilduff
- Biosciences Division, Center for Neuroscience, SRI International, 333 Ravenswood Avenue, Menlo Park, CA 94025, USA.
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Distribution of histaminergic neuronal cluster in the rat and mouse hypothalamus. J Chem Neuroanat 2015; 68:1-13. [DOI: 10.1016/j.jchemneu.2015.07.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Revised: 06/11/2015] [Accepted: 07/01/2015] [Indexed: 01/03/2023]
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Graebner AK, Iyer M, Carter ME. Understanding how discrete populations of hypothalamic neurons orchestrate complicated behavioral states. Front Syst Neurosci 2015; 9:111. [PMID: 26300745 PMCID: PMC4523943 DOI: 10.3389/fnsys.2015.00111] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2014] [Accepted: 07/16/2015] [Indexed: 01/01/2023] Open
Abstract
A major question in systems neuroscience is how a single population of neurons can interact with the rest of the brain to orchestrate complex behavioral states. The hypothalamus contains many such discrete neuronal populations that individually regulate arousal, feeding, and drinking. For example, hypothalamic neurons that express hypocretin (Hcrt) neuropeptides can sense homeostatic and metabolic factors affecting wakefulness and orchestrate organismal arousal. Neurons that express agouti-related protein (AgRP) can sense the metabolic needs of the body and orchestrate a state of hunger. The organum vasculosum of the lamina terminalis (OVLT) can detect the hypertonicity of blood and orchestrate a state of thirst. Each hypothalamic population is sufficient to generate complicated behavioral states through the combined efforts of distinct efferent projections. The principal challenge to understanding these brain systems is therefore to determine the individual roles of each downstream projection for each behavioral state. In recent years, the development and application of temporally precise, genetically encoded tools has greatly improved our understanding of the structure and function of these neural systems. This review will survey recent advances in our understanding of how these individual hypothalamic populations can orchestrate complicated behavioral states due to the combined efforts of individual downstream projections.
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Affiliation(s)
- Allison K Graebner
- Program in Neuroscience, Department of Biology, Williams College Williamstown, MA, USA
| | - Manasi Iyer
- Program in Neuroscience, Department of Biology, Williams College Williamstown, MA, USA
| | - Matthew E Carter
- Program in Neuroscience, Department of Biology, Williams College Williamstown, MA, USA
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Carvajal F, Alcaraz-Iborra M, Lerma-Cabrera JM, Valor LM, de la Fuente L, Sanchez-Amate MDC, Cubero I. Orexin receptor 1 signaling contributes to ethanol binge-like drinking: Pharmacological and molecular evidence. Behav Brain Res 2015; 287:230-7. [DOI: 10.1016/j.bbr.2015.03.046] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Revised: 03/03/2015] [Accepted: 03/22/2015] [Indexed: 12/27/2022]
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Riahi E, Arezoomandan R, Fatahi Z, Haghparast A. The electrical activity of hippocampal pyramidal neuron is subjected to descending control by the brain orexin/hypocretin system. Neurobiol Learn Mem 2015; 119:93-101. [DOI: 10.1016/j.nlm.2015.02.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Revised: 12/23/2014] [Accepted: 02/03/2015] [Indexed: 11/16/2022]
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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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Alcaraz-Iborra M, Carvajal F, Lerma-Cabrera JM, Valor LM, Cubero I. Binge-like consumption of caloric and non-caloric palatable substances in ad libitum-fed C57BL/6J mice: Pharmacological and molecular evidence of orexin involvement. Behav Brain Res 2014; 272:93-9. [DOI: 10.1016/j.bbr.2014.06.049] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2014] [Revised: 06/16/2014] [Accepted: 06/23/2014] [Indexed: 10/25/2022]
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Li J, Hu Z, de Lecea L. The hypocretins/orexins: integrators of multiple physiological functions. Br J Pharmacol 2014; 171:332-50. [PMID: 24102345 DOI: 10.1111/bph.12415] [Citation(s) in RCA: 186] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2013] [Revised: 07/16/2013] [Accepted: 08/02/2013] [Indexed: 12/28/2022] Open
Abstract
The hypocretins (Hcrts), also known as orexins, are two peptides derived from a single precursor produced in the posterior lateral hypothalamus. Over the past decade, the orexin system has been associated with numerous physiological functions, including sleep/arousal, energy homeostasis, endocrine, visceral functions and pathological states, such as narcolepsy and drug abuse. Here, we review the discovery of Hcrt/orexins and their receptors and propose a hypothesis as to how the orexin system orchestrates these multifaceted physiological functions.
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Affiliation(s)
- Jingcheng Li
- Department of Physiology, Third Military Medical University, Chongqing, China
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41
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De la Herrán-Arita AK, García-García F. Current and emerging options for the drug treatment of narcolepsy. Drugs 2014; 73:1771-81. [PMID: 24122734 DOI: 10.1007/s40265-013-0127-y] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Narcolepsy/hypocretin deficiency (now called type 1 narcolepsy) is a lifelong neurologic disorder with well-established diagnostic criteria and etiology. Narcolepsy is a chronic sleep disorder characterized by excessive daytime sleepiness (EDS) and symptoms of dissociated rapid eye movement sleep such as cataplexy (sudden loss of muscle tone), hypnagogic hallucinations (sensory events that occur at the transition from wakefulness to sleep), sleep paralysis (inability to perform movements upon wakening or sleep onset), and nocturnal sleep disruption. As these symptoms are often disabling, most patients need life-long treatment. The treatment of narcolepsy is well defined, and, traditionally, amphetamine-like stimulants (i.e., dopaminergic release enhancers) have been used for clinical management to improve EDS and sleep attacks, whereas tricyclic antidepressants have been used as anticataplectics. However, treatments have evolved to better-tolerated compounds such as modafinil or armodafinil (for EDS) and adrenergic/serotonergic selective reuptake inhibitors (as anticataplectics). In addition, night-time administration of a short-acting sedative, c-hydroxybutyrate (sodium oxybate), has been used for the treatment for EDS and cataplexy. These therapies are almost always needed in combination with non-pharmacologic treatments (i.e., behavioral modification). A series of new drugs is currently being tested in animal models and in humans. These include a wide variety of hypocretin agonists, melanin- concentrating hormone receptor antagonists, antigenspecific immunopharmacology, and histamine H3 receptor antagonists/inverse agonists (e.g., pitolisant), which have been proposed for specific therapeutic applications, including the treatment of Alzheimer's disease, attention-deficit hyperactivity disorder, epilepsy, and more recently, narcolepsy. Even though current treatment is strictly symptomatic, based on the present state of knowledge of the pathophysiology of narcolepsy, we expect that more pathophysiology-based treatments will be available in the near future.
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Wang ZH, Ni XL, Li JN, Xiao ZY, Wang C, Zhang LN, Tong L, Dong HL. Changes in plasma orexin-A levels in sevoflurane-remifentanil anesthesia in young and elderly patients undergoing elective lumbar surgery. Anesth Analg 2014; 118:818-22. [PMID: 24651236 DOI: 10.1213/ane.0000000000000109] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
BACKGROUND Delayed emergence from general anesthesia frequently occurs in elderly patients, but the reason is not clear. Orexin has been shown to be involved in arousal from general anesthesia. In this study, we examined plasma orexin-A levels in both elderly and young patients during the anesthesia arousal cycle. METHODS We recruited 41 patients scheduled for elective lumbar surgery and eventually evaluated 34 patients. Patients were divided into a young group (age 30-55, N = 16) and an elderly group (age 65-77, N = 18). Anesthesia with sevoflurane-remifentanil was titrated to maintain the Bispectral Index between 45 and 65. The times from stopping anesthesia to eyes opening and extubation were recorded. Arterial blood was collected, and plasma orexin-A was determined by radioimmunoassay at the following 4 time points: preanesthesia (T0), 1 hour after anesthesia induction (T1), emergence (5 minutes after tracheal extubation) (T2), and 30 minutes after tracheal extubation (T3). RESULTS The times from stopping anesthesia to eyes opening and tracheal extubation were both significantly longer in the elderly group than in the young group (P = 0.004, P = 0.01, respectively). Basal (T0) orexin-A levels were higher in the elderly group than in the young group (T0, 26.13 ± 1.25 vs 17.9 ± 1.30 pg/mL, P < 0.0001). Plasma orexin-A levels did not change during induction of anesthesia in either group but significantly increased at T2 (vs T0, P <0.0001) in both elderly (35.0 ± 1.7 pg/mL) and young (29.2 ± 1.9 pg/mL) groups. Orexin-A levels were significantly higher in the elderly than in the young group at T1, T2, and T3. CONCLUSION Plasma orexin-A levels are not responsible for the delayed emergence from general anesthesia in elderly patients.
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Affiliation(s)
- Zhi-Hua Wang
- From the Department of Anesthesiology, Xijing Hospital, Fourth Military Medical University, Shaanxi, China
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43
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de Lecea L, Huerta R. Hypocretin (orexin) regulation of sleep-to-wake transitions. Front Pharmacol 2014; 5:16. [PMID: 24575043 PMCID: PMC3921570 DOI: 10.3389/fphar.2014.00016] [Citation(s) in RCA: 84] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Accepted: 01/27/2014] [Indexed: 12/17/2022] Open
Abstract
The hypocretin (Hcrt), also known as orexin, peptides are essential for arousal stability. Here we discuss background information about the interaction of Hcrt with other neuromodulators, including norepinephrine and acetylcholine probed with optogenetics. We conclude that Hcrt neurons integrate metabolic, circadian and limbic inputs and convey this information to a network of neuromodulators, each of which has a different role on the dynamic of sleep-to-wake transitions. This model may prove useful to predict the effects of orexin receptor antagonists in sleep disorders and other conditions.
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Affiliation(s)
- Luis de Lecea
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA, USA
| | - Ramón Huerta
- BioCircuits Institute, University of California, San Diego, La Jolla, CA, USA
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Hasegawa E, Yanagisawa M, Sakurai T, Mieda M. Orexin neurons suppress narcolepsy via 2 distinct efferent pathways. J Clin Invest 2014; 124:604-16. [PMID: 24382351 DOI: 10.1172/jci71017] [Citation(s) in RCA: 116] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Accepted: 10/15/2013] [Indexed: 11/17/2022] Open
Abstract
The loss of orexin neurons in humans is associated with the sleep disorder narcolepsy, which is characterized by excessive daytime sleepiness and cataplexy. Mice lacking orexin peptides, orexin neurons, or orexin receptors recapitulate human narcolepsy phenotypes, further highlighting a critical role for orexin signaling in the maintenance of wakefulness. Despite the known role of orexin neurons in narcolepsy, the precise neural mechanisms downstream of these neurons remain unknown. We found that targeted restoration of orexin receptor expression in the dorsal raphe (DR) and in the locus coeruleus (LC) of mice lacking orexin receptors inhibited cataplexy-like episodes and pathological fragmentation of wakefulness (i.e., sleepiness), respectively. The suppression of cataplexy-like episodes correlated with the number of serotonergic neurons restored with orexin receptor expression in the DR, while the consolidation of fragmented wakefulness correlated with the number of noradrenergic neurons restored in the LC. Furthermore, pharmacogenetic activation of these neurons using designer receptor exclusively activated by designer drug (DREADD) technology ameliorated narcolepsy in mice lacking orexin neurons. These results suggest that DR serotonergic and LC noradrenergic neurons play differential roles in orexin neuron-dependent regulation of sleep/wakefulness and highlight a pharmacogenetic approach for the amelioration of narcolepsy.
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45
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Leonard CS, Kukkonen JP. Orexin/hypocretin receptor signalling: a functional perspective. Br J Pharmacol 2014; 171:294-313. [PMID: 23848055 PMCID: PMC3904253 DOI: 10.1111/bph.12296] [Citation(s) in RCA: 103] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2013] [Revised: 06/17/2013] [Accepted: 07/03/2013] [Indexed: 10/26/2022] Open
Abstract
Multiple homeostatic systems are regulated by orexin (hypocretin) peptides and their two known GPCRs. Activation of orexin receptors promotes waking and is essential for expression of normal sleep and waking behaviour, with the sleep disorder narcolepsy resulting from the absence of orexin signalling. Orexin receptors also influence systems regulating appetite/metabolism, stress and reward, and are found in several peripheral tissues. Nevertheless, much remains unknown about the signalling pathways and targets engaged by native receptors. In this review, we integrate knowledge about the orexin receptor signalling capabilities obtained from studies in expression systems and various native cell types (as presented in Kukkonen and Leonard, this issue of British Journal of Pharmacology) with knowledge of orexin signalling in different tissues. The tissues reviewed include the CNS, the gastrointestinal tract, the pituitary gland, pancreas, adrenal gland, adipose tissue and the male reproductive system. We also summarize the findings in different native and recombinant cell lines, especially focusing on the different cascades in CHO cells, which is the most investigated cell line. This reveals that while a substantial gap exists between what is known about orexin receptor signalling and effectors in recombinant systems and native systems, mounting evidence suggests that orexin receptor signalling is more diverse than originally thought. Moreover, rather than being restricted to orexin receptor 'overexpressing' cells, this signalling diversity may be utilized by native receptors in a site-specific manner.
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Affiliation(s)
- C S Leonard
- Department of Physiology, New York Medical College, Valhalla, NY, USA
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46
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Aracri P, Banfi D, Pasini ME, Amadeo A, Becchetti A. Hypocretin (orexin) regulates glutamate input to fast-spiking interneurons in layer V of the Fr2 region of the murine prefrontal cortex. Cereb Cortex 2013; 25:1330-47. [PMID: 24297328 PMCID: PMC4397574 DOI: 10.1093/cercor/bht326] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
We studied the effect of hypocretin 1 (orexin A) in the frontal area 2 (Fr2) of the murine neocortex, implicated in the motivation-dependent goal-directed tasks. In layer V, hypocretin stimulated the spontaneous excitatory postsynaptic currents (EPSCs) on fast-spiking (FS) interneurons. The effect was accompanied by increased frequency of miniature EPSCs, indicating that hypocretin can target the glutamatergic terminals. Moreover, hypocretin stimulated the spontaneous inhibitory postsynaptic currents (IPSCs) on pyramidal neurons, with no effect on miniature IPSCs. This action was prevented by blocking 1) the ionotropic glutamatergic receptors; 2) the hypocretin receptor type 1 (HCRTR-1), with SB-334867. Finally, hypocretin increased the firing frequency in FS cells, and the effect was blocked when the ionotropic glutamate transmission was inhibited. Immunolocalization confirmed that HCRTR-1 is highly expressed in Fr2, particularly in layer V-VI. Conspicuous labeling was observed in pyramidal neuron somata and in VGLUT1+ glutamatergic terminals, but not in VGLUT2+ fibers (mainly thalamocortical afferents). The expression of HCRTR-1 in GABAergic structures was scarce. We conclude that 1) hypocretin regulates glutamate release in Fr2; 2) the effect presents a presynaptic component; 3) the peptide control of FS cells is indirect, and probably mediated by the regulation of glutamatergic input onto these cells.
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Affiliation(s)
- Patrizia Aracri
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milan 20126, Italy
| | - Daniele Banfi
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milan 20126, Italy
| | - Maria Enrica Pasini
- Department of Biomolecular Sciences and Biotechnology, University of Milano, Milan 20128, Italy
| | - Alida Amadeo
- Department of Biomolecular Sciences and Biotechnology, University of Milano, Milan 20128, Italy
| | - Andrea Becchetti
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milan 20126, Italy
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The effects of bilateral lesions of the mesencephalic trigeminal sensory nucleus on nocturnal feeding and related behaviors in mice. Life Sci 2013; 93:681-6. [PMID: 24063988 DOI: 10.1016/j.lfs.2013.09.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Revised: 07/26/2013] [Accepted: 09/09/2013] [Indexed: 11/20/2022]
Abstract
AIMS The mesencephalic trigeminal sensory nucleus (Me5), which receives signals originating from oral proprioceptors and projects its fibers to the hypothalamus, regulates mastication and modulates satiation. Because the Me5 neurons display circadian rhythms in circadian mPer1 gene expression and bilateral Me5 lesions change feeding and exploratory behavior profiles, we speculated that Me5 may influence the daily timing of feeding. Therefore, we explored the effects of bilateral caudal Me5 lesions on the circadian profiles of feeding and its related behaviors. MAIN METHODS We measured the activities of feeding, drinking, and locomotion for 24h using an automated feeding behavior measurement apparatus and analyzed the mRNA expression levels of hypothalamic orexigenic and anorexigenic signaling molecules in both Me5-lesioned and sham-operated mice. KEY FINDINGS Food and water intake and locomotor activity decreased significantly in Me5-lesioned mice during the dark phase without affecting these total indexes when measured over the entire day. Analysis of the mRNA expression levels of hypothalamic orexigenic and anorexigenic signaling molecules showed that prepro-orexin (orexin) mRNA in the perifornical area was significantly decreased during the dark phase only in Me5-lesioned mice. SIGNIFICANCE Bilateral caudal Me5 lesions alter the nocturnal properties of food and water intake and locomotor activity in mice and decrease the mRNA expression level of orexin in the perifornical area during the dark phase. These results suggest that Me5 activity may influence the nocturnal properties of feeding and its related behaviors by adjusting the activity of orexin neurons in the perifornical area.
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The histaminergic network in the brain: basic organization and role in disease. Nat Rev Neurosci 2013; 14:472-87. [DOI: 10.1038/nrn3526] [Citation(s) in RCA: 225] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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49
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Perez-Leighton CE, Billington CJ, Kotz CM. Orexin modulation of adipose tissue. Biochim Biophys Acta Mol Basis Dis 2013; 1842:440-5. [PMID: 23791983 DOI: 10.1016/j.bbadis.2013.06.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2013] [Revised: 05/23/2013] [Accepted: 06/05/2013] [Indexed: 10/26/2022]
Abstract
The orexins are neuropeptides with critical functions in the central nervous system. These neuropeptides have important roles in energy balance and obesity, and therefore on the accumulation of adipose tissue. Rodents lacking orexins, typically through genetic knockouts, experience increased weight gain and accumulation of adipose tissue. Evidence indicates that the lack of the orexins increase adiposity as a result of decreased energy expenditure, principally through a reduction of physical activity. Different lines of evidence suggest that other mechanisms are likely also in play, and neural influences on both white and brown adipose tissues remain to be fully and functionally defined. In addition, the orexin peptides and their receptors are expressed in adipose tissue, with little available information as to their significance. This review summarizes our current understanding of how the orexin peptides affect adipose tissue. We provide a brief introduction to the physiology of orexins and their effects on white and brown adipose tissues in the context of energy balance. We conclude this review by integrating this information in the context of the known physiology of the orexins. This article is part of a Special Issue entitled: Modulation of Adipose Tissue in Health and Disease.
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Affiliation(s)
- Claudio E Perez-Leighton
- Veterans Health Care System, GRECC, One Veterans Drive, Minneapolis, MN 55417, USA; University of Minnesota, MN Obesity Center, 1334 Eckles Avenue, St Paul, MN 55108, USA; Center for Integrative Medicine and Innovative Sciences, Facultad de Medicina, Universidad Andres Bello, Echaurren 183, Santiago, 8370071, Chile.
| | - Charles J Billington
- Veterans Health Care System, Endocrinology, One Veterans Drive, Minneapolis, MN 55417, USA; University of Minnesota, MN Obesity Center, 1334 Eckles Avenue, St Paul, MN 55108, USA; University of Minnesota, Graduate Program in Nutrition, 1334 Eckles Avenue, St Paul, MN 55108, USA
| | - Catherine M Kotz
- Veterans Health Care System, GRECC, One Veterans Drive, Minneapolis, MN 55417, USA; University of Minnesota, MN Obesity Center, 1334 Eckles Avenue, St Paul, MN 55108, USA; University of Minnesota, Department of Food Science and Nutrition, 1334 Eckles Avenue, St Paul, MN 55108, USA; University of Minnesota, Graduate Program in Nutrition, 1334 Eckles Avenue, St Paul, MN 55108, USA; University of Minnesota, Graduate Program in Neuroscience, USA
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Tsunematsu T, Tabuchi S, Tanaka KF, Boyden ES, Tominaga M, Yamanaka A. Long-lasting silencing of orexin/hypocretin neurons using archaerhodopsin induces slow-wave sleep in mice. Behav Brain Res 2013; 255:64-74. [PMID: 23707248 DOI: 10.1016/j.bbr.2013.05.021] [Citation(s) in RCA: 94] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2012] [Revised: 04/08/2013] [Accepted: 05/14/2013] [Indexed: 11/24/2022]
Abstract
Orexin/hypocretin neurons have a crucial role in the regulation of sleep and wakefulness. Recent optogenetic studies revealed that the activation or inhibition of orexin neuronal activity affects the probability of sleep/wakefulness transition in the acute phase. To expand our understanding of how orexin neurons maintain wakefulness, we generated new transgenic mice in which orexin neurons expressed archaerhodopsin from Halorubrum strain TP009 (ArchT), a green light-driven neuronal silencer, using the tet-off system (orexin-tTA; TetO ArchT mice). Slice patch clamp recordings of ArchT-expressing orexin neurons demonstrated that long-lasting photic illumination was able to silence the activity of orexin neurons. We further confirmed that green light illumination for 1h in the dark period suppressed orexin neuronal activity in vivo using c-Fos expression. Continuous 1h silencing of orexin neurons in freely moving orexin-tTA; TetO ArchT mice during the night (the active period, 20:00-21:00) significantly increased total time spent in slow-wave sleep (SWS) and decreased total wake time. Additionally, photic inhibition increased sleep/wakefulness state transitions, which is also evident in animals lacking the prepro-orexin gene, orexin neurons, or functional orexin-2 receptors. However, continuous 1h photic illumination produced little effect on sleep/wakefulness states during the day (the inactive period, 12:00-13:00). These results suggest that orexin neuronal activity plays a crucial role in the maintenance of wakefulness especially in the active phase in mice.
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Affiliation(s)
- Tomomi Tsunematsu
- Division of Cell Signaling, Okazaki Institute for Integrative Bioscience, National Institute for Physiological Sciences, Okazaki 444-8787, Japan; The Japan Society for the Promotion of Sciences, Tokyo 102-8472, Japan
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