1
|
Biscarini F, Barateau L, Pizza F, Plazzi G, Dauvilliers Y. Narcolepsy and rapid eye movement sleep. J Sleep Res 2024:e14277. [PMID: 38955433 DOI: 10.1111/jsr.14277] [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: 05/07/2024] [Revised: 06/06/2024] [Accepted: 06/09/2024] [Indexed: 07/04/2024]
Abstract
Since the first description of narcolepsy at the end of the 19th Century, great progress has been made. The disease is nowadays distinguished as narcolepsy type 1 and type 2. In the 1960s, the discovery of rapid eye movement sleep at sleep onset led to improved understanding of core sleep-related disease symptoms of the disease (excessive daytime sleepiness with early occurrence of rapid eye movement sleep, sleep-related hallucinations, sleep paralysis, rapid eye movement parasomnia), as possible dysregulation of rapid eye movement sleep, and cataplexy resembling an intrusion of rapid eye movement atonia during wake. The relevance of non-sleep-related symptoms, such as obesity, precocious puberty, psychiatric and cardiovascular morbidities, has subsequently been recognized. The diagnostic tools have been improved, but sleep-onset rapid eye movement periods on polysomnography and Multiple Sleep Latency Test remain key criteria. The pathogenic mechanisms of narcolepsy type 1 have been partly elucidated after the discovery of strong HLA class II association and orexin/hypocretin deficiency, a neurotransmitter that is involved in altered rapid eye movement sleep regulation. Conversely, the causes of narcolepsy type 2, where cataplexy and orexin deficiency are absent, remain unknown. Symptomatic medications to treat patients with narcolepsy have been developed, and management has been codified with guidelines, until the recent promising orexin-receptor agonists. The present review retraces the steps of the research on narcolepsy that linked the features of the disease with rapid eye movement sleep abnormality, and those that do not appear associated with rapid eye movement sleep.
Collapse
Affiliation(s)
- Francesco Biscarini
- Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, Bologna, Italy
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy
| | - Lucie Barateau
- Sleep-Wake Disorders Unit, Department of Neurology, Gui-de-Chauliac Hospital, CHU Montpellier, Montpellier, France
- National Reference Centre for Orphan Diseases, Narcolepsy, Idiopathic Hypersomnia, and Kleine-Levin Syndrome, Montpellier, France
- Institute for Neurosciences of Montpellier, University of Montpellier, INSERM, Montpellier, France
| | - Fabio Pizza
- Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, Bologna, Italy
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy
| | - Giuseppe Plazzi
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio-Emilia, Modena, Italy
| | - Yves Dauvilliers
- Sleep-Wake Disorders Unit, Department of Neurology, Gui-de-Chauliac Hospital, CHU Montpellier, Montpellier, France
- National Reference Centre for Orphan Diseases, Narcolepsy, Idiopathic Hypersomnia, and Kleine-Levin Syndrome, Montpellier, France
- Institute for Neurosciences of Montpellier, University of Montpellier, INSERM, Montpellier, France
| |
Collapse
|
2
|
Nirogi R, Jayarajan P, Benade V, Abraham R, Goyal VK. Hits and misses with animal models of narcolepsy and the implications for drug discovery. Expert Opin Drug Discov 2024; 19:755-768. [PMID: 38747534 DOI: 10.1080/17460441.2024.2354293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2024] [Accepted: 05/08/2024] [Indexed: 05/22/2024]
Abstract
INTRODUCTION Narcolepsy is a chronic and rare neurological disorder characterized by disordered sleep. Based on animal models and further research in humans, the dysfunctional orexin system was identified as a contributing factor to the pathophysiology of narcolepsy. Animal models played a larger role in the discovery of some of the pharmacological agents with established benefit/risk profiles. AREAS COVERED In this review, the authors examine the phenotypes observed in animal models of narcolepsy and the characteristics of clinically used pharmacological agents in these animal models. Additionally, the authors compare the effects of clinically used pharmacological agents on the phenotypes in animal models with those observed in narcolepsy patients. EXPERT OPINION Research in canine and mouse models have linked narcolepsy to the O×R2mutation and orexin deficiency, leading to new diagnostic criteria and a drug development focus. Advancements in pharmacological therapies have significantly improved narcolepsy management, with insights from both clinical experience and from animal models having led to new treatments such as low sodium oxybate and solriamfetol. However, challenges persist in addressing symptoms beyond excessive daytime sleepiness and cataplexy, highlighting the need for further research, including the development of diurnal animal models to enhance understanding and treatment options for narcolepsy.
Collapse
Affiliation(s)
- Ramakrishna Nirogi
- Drug Discovery & Development, Suven Life Sciences Limited, Hyderabad, India
| | - Pradeep Jayarajan
- Drug Discovery & Development, Suven Life Sciences Limited, Hyderabad, India
| | - Vijay Benade
- Drug Discovery & Development, Suven Life Sciences Limited, Hyderabad, India
| | - Renny Abraham
- Drug Discovery & Development, Suven Life Sciences Limited, Hyderabad, India
| | - Vinod Kumar Goyal
- Drug Discovery & Development, Suven Life Sciences Limited, Hyderabad, India
| |
Collapse
|
3
|
Mitler MM. Fifty-five years in sleep research: contributions, experiences, and progress. SLEEP ADVANCES : A JOURNAL OF THE SLEEP RESEARCH SOCIETY 2023; 4:zpad021. [PMID: 37293514 PMCID: PMC10246585 DOI: 10.1093/sleepadvances/zpad021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 03/10/2023] [Indexed: 06/10/2023]
Affiliation(s)
- Merrill M Mitler
- Corresponding author. Merrill M. Mitler, Scientific Consultant, Commonwealth Health Research Board, Richmond, VA, USA.
| |
Collapse
|
4
|
Carrera-Cañas C, de Andrés I, Callejo M, Garzón M. Plasticity of the hypocretinergic/orexinergic system after a chronic treatment with suvorexant in rats. Role of the hypocretinergic/orexinergic receptor 1 as an autoreceptor. Front Mol Neurosci 2022; 15:1013182. [PMID: 36277486 PMCID: PMC9581150 DOI: 10.3389/fnmol.2022.1013182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2022] [Accepted: 09/13/2022] [Indexed: 12/02/2022] Open
Abstract
The hypothalamic hypocretinergic/orexinergic (Hcrt/Ox) system is involved in many physiological and pathophysiological processes. Malfunction of Hcrt/Ox transmission results in narcolepsy, a sleep disease caused in humans by progressive neurodegeneration of hypothalamic neurons containing Hcrt/Ox. To explore the Hcrt/Ox system plasticity we systemically administered suvorexant (a dual Hcrt/Ox receptor antagonist) in rats to chronically block Hcrt/Ox transmission without damaging Hcrt/Ox cells. Three groups of eight rats (four males and four females) received daily i.p. injections of suvorexant (10 or 30 mg/kg) or vehicle (DMSO) over a period of 7 days in which the body weight was monitored. After the treatments cerebrospinal fluid (CSF) Hcrt1/OxA concentration was measured by ELISA, and hypothalamic Hcrt/OxR1 and Hcrt/OxR2 levels by western blot. The systemic blockade of the Hcrt/Ox transmission with the suvorexant high dose produced a significant increase in body weight at the end of the treatment, and a significant decrease in CSF Hcrt1/OxA levels, both features typical in human narcolepsy type 1. Besides, a significant overexpression of hypothalamic Hcrt/OxR1 occurred. For the Hcrt/OxR2 two very close bands were detected, but they did not show significant changes with the treatment. Thus, the plastic changes observed in the Hcrt/Ox system after the chronic blockade of its transmission were a decrease in CSF Hcrt1/OXA levels and an overexpression of hypothalamic Hcrt/OxR1. These findings support an autoregulatory role of Hcrt/OxR1 within the hypothalamus, which would induce the synthesis/release of Hcrt/Ox, but also decrease its own availability at the plasma membrane after binding Hcrt1/OxA to preserve Hcrt/Ox system homeostasis.
Collapse
|
5
|
Ono T, Takenoshita S, Nishino S. Pharmacologic Management of Excessive Daytime Sleepiness. Sleep Med Clin 2022; 17:485-503. [PMID: 36150809 DOI: 10.1016/j.jsmc.2022.06.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Abstract
Excessive daytime sleepiness (EDS) is defined as "irresistible sleepiness in a situation when an individual would be expected to be awake, and alert." EDS has been a big concern not only from a medical but also from a public health point of view. Patients with EDS have the possibility of falling asleep even when they should wake up and concentrate, for example, when they drive, play sports, or walk outside. In this article, clinical characteristics of common hypersomnia and pharmacologic treatments of each hypersomnia are described.
Collapse
Affiliation(s)
- Taisuke Ono
- Sleep and Circadian Neurobiology Laboratory, Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Palo Alto, CA, USA; Department of Geriatric Medicine, Kanazawa Medical University School of Medicine, Ishikawa, Japan.
| | - Shinichi Takenoshita
- Sleep and Circadian Neurobiology Laboratory, Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Palo Alto, CA, USA
| | - Seiji Nishino
- Sleep and Circadian Neurobiology Laboratory, Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Palo Alto, CA, USA
| |
Collapse
|
6
|
Orexin 2 receptor-selective agonist danavorexton improves narcolepsy phenotype in a mouse model and in human patients. Proc Natl Acad Sci U S A 2022; 119:e2207531119. [PMID: 35994639 PMCID: PMC9436334 DOI: 10.1073/pnas.2207531119] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Narcolepsy type 1 (NT1) is a sleep disorder caused by a loss of orexinergic neurons. Narcolepsy type 2 (NT2) is heterogeneous; affected individuals typically have normal orexin levels. Following evaluation in mice, the effects of the orexin 2 receptor (OX2R)-selective agonist danavorexton were evaluated in single- and multiple-rising-dose studies in healthy adults, and in individuals with NT1 and NT2. In orexin/ataxin-3 narcolepsy mice, danavorexton reduced sleep/wakefulness fragmentation and cataplexy-like episodes during the active phase. In humans, danavorexton administered intravenously was well tolerated and was associated with marked improvements in sleep latency in both NT1 and NT2. In individuals with NT1, danavorexton dose-dependently increased sleep latency in the Maintenance of Wakefulness Test, up to the ceiling effect of 40 min, in both the single- and multiple-rising-dose studies. These findings indicate that OX2Rs remain functional despite long-term orexin loss in NT1. OX2R-selective agonists are a promising treatment for both NT1 and NT2.
Collapse
|
7
|
Azeez IA, Igado OO, Olopade JO. An overview of the orexinergic system in different animal species. Metab Brain Dis 2021; 36:1419-1444. [PMID: 34224065 DOI: 10.1007/s11011-021-00761-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 06/06/2021] [Indexed: 01/13/2023]
Abstract
Orexin (hypocretin), is a neuropeptide produced by a subset of neurons in the lateral hypothalamus. From the lateral hypothalamus, the orexin-containing neurons project their fibres extensively to other brain structures, and the spinal cord constituting the central orexinergic system. Generally, the term ''orexinergic system'' usually refers to the orexin peptides and their receptors, as well as to the orexin neurons and their projections to different parts of the central nervous system. The extensive networks of orexin axonal fibres and their terminals allow these neuropeptidergic neurons to exert great influence on their target regions. The hypothalamic neurons containing the orexin neuropeptides have been implicated in diverse functions, especially related to the control of a variety of homeostatic functions including feeding behaviour, arousal, wakefulness stability and energy expenditure. The broad range of functions regulated by the orexinergic system has led to its description as ''physiological integrator''. In the last two decades, the orexinergic system has been a topic of great interest to the scientific community with many reports in the public domain. From the documentations, variations exist in the neuroanatomical profile of the orexinergic neuron soma, fibres and their receptors from animal to animal. Hence, this review highlights the distinct variabilities in the morphophysiological aspects of the orexinergic system in the vertebrate animals, mammals and non-mammals, its presence in other brain-related structures, including its involvement in ageing and neurodegenerative diseases. The presence of the neuropeptide in the cerebrospinal fluid and peripheral tissues, as well as its alteration in different animal models and conditions are also reviewed.
Collapse
Affiliation(s)
- Idris A Azeez
- Department of Veterinary Anatomy, University of Jos, Jos, Nigeria
| | - Olumayowa O Igado
- Department of Veterinary Anatomy, University of Ibadan, Ibadan, Nigeria
| | - James O Olopade
- Department of Veterinary Anatomy, University of Ibadan, Ibadan, Nigeria.
| |
Collapse
|
8
|
What do I talk about when I talk about measuring CNS orexin-A? Considerations of orexin-A measurements in clinical and preclinical setting. MEDICINE IN DRUG DISCOVERY 2021. [DOI: 10.1016/j.medidd.2021.100101] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
|
9
|
Tisdale RK, Yamanaka A, Kilduff TS. Animal models of narcolepsy and the hypocretin/orexin system: Past, present, and future. Sleep 2021; 44:6031626. [PMID: 33313880 DOI: 10.1093/sleep/zsaa278] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 12/04/2020] [Indexed: 11/12/2022] Open
Abstract
Animal models have advanced not only our understanding of the etiology and phenotype of the sleep disorder narcolepsy but have also informed sleep/wake regulation more generally. The identification of an inheritable narcolepsy phenotype in dogs in the 1970s allowed the establishment of a breeding colony at Stanford University, resulting in studies that provided the first insights into the genetics and neurotransmitter systems that underlie cataplexy and rapid-eye movement sleep atonia. Although the discovery of the hypocretin/orexin neuropeptides in 1998 initially seemed unrelated to sleep/wake control, the description of the phenotype of the prepro-orexin knockout (KO) mouse as strongly resembling cataplexy, the pathognomonic symptom of narcolepsy, along with identification of a mutation in hypocretin receptor-2 gene as the source of canine narcolepsy, unequivocally established the relationship between this system and narcolepsy. The subsequent discovery of hypocretin neuron degeneration in human narcolepsy demystified a disorder whose etiology had been unknown since its initial description 120 years earlier. These breakthroughs prompted the development of numerous other animal models that have allowed manipulation of the hypocretin/orexin system, thereby advancing our understanding of sleep/wake circuitry. While animal models have greatly informed understanding of this fascinating disorder and the role of the hypocretin/orexin system in sleep/wake control, the question of why these neurons degenerate in human narcolepsy is only beginning to be understood. The development of new immune-mediated narcolepsy models are likely to further inform the etiology of this sleep disorder and animal models will undoubtedly play a critical role in the development of novel narcolepsy therapeutics.
Collapse
Affiliation(s)
- Ryan K Tisdale
- Center for Neuroscience, Biosciences Division, SRI International
| | - Akihiro Yamanaka
- Department of Neuroscience II, Research Institute of Environmental Medicine, Nagoya University, Japan.,Department of Neural Regulation, Nagoya University Graduate School of Medicine, Japan
| | - Thomas S Kilduff
- Center for Neuroscience, Biosciences Division, SRI International
| |
Collapse
|
10
|
Liatis T, Theodorou K, Kasabalis D, Soubasis N, Panopoulos I, Polizopoulou Z. What Is Your Neurologic Diagnosis? J Am Vet Med Assoc 2021; 258:1337-1340. [PMID: 34061617 DOI: 10.2460/javma.258.12.1337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
11
|
Santifort KM, Ives EJ, Fenn J, Raimondi F, Lourinho F, Mandigers PJJ, Bergknut N. Suspected acquired narcolepsy in 8 dogs. J Vet Intern Med 2021; 35:1448-1454. [PMID: 33960533 PMCID: PMC8162612 DOI: 10.1111/jvim.16116] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 03/11/2021] [Accepted: 03/22/2021] [Indexed: 01/11/2023] Open
Abstract
Background Acquired narcolepsy has rarely been reported in veterinary medicine. Objective To describe the presentation, clinicopathological features, diagnostic imaging findings, and management of dogs with suspected‐acquired narcolepsy. Animals Eight dogs with clinical features consistent with acquired narcolepsy. Methods A call for suspected cases of acquired narcolepsy was made online, followed by a retrospective review of detailed medical records of potential cases. Dogs were included if episodes consistent with cataplexy were present during examination by a board‐certified veterinary neurologist and diagnostic work‐up included magnetic resonance imaging of the brain and analysis of cerebrospinal fluid. Results Seven French Bulldogs and 1 Chihuahua (age range, 9‐66 months) were included. Meningoencephalitis of unknown origin was diagnosed in 2 dogs, extracranial foci of inflammation were identified in 2 dogs (aspiration pneumonia, esophagitis, otitis media), and no abnormalities were found on diagnostic investigations in 4 dogs. Prednisolone was used in the management of all dogs, 6 dogs received imipramine, and 2 received cytosine arabinoside. An initial remission of signs was observed in all dogs, but a subsequent relapse of clinical signs was recorded for 4 dogs, of which 3 responded to adjustment or resumption of treatment. Conclusions and Clinical Importance The presence of cataplexy episodes should prompt a thorough diagnostic work‐up to exclude the presence of intracranial (and extracranial) pathology. The potential for both remission and relapse of signs in suspected acquired cases is important for clinicians and owners to be aware of.
Collapse
Affiliation(s)
- Koen M Santifort
- Evidensia Small Animal Hospital, Arnhem, The Netherlands.,Evidensia Small Animal Hospital 'Hart van Brabant', Waalwijk, The Netherlands
| | - Edward J Ives
- Anderson Moores Veterinary Specialists, Winchester, UK
| | - Joe Fenn
- Department of Clinical Science and Services, Royal Veterinary College, Hatfield, UK
| | | | | | - Paul J J Mandigers
- Evidensia Small Animal Hospital, Arnhem, The Netherlands.,Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, University of Utrecht, Utrecht, The Netherlands
| | - Niklas Bergknut
- Evidensia Small Animal Hospital 'Hart van Brabant', Waalwijk, The Netherlands
| |
Collapse
|
12
|
Sleep Disorders in dogs: A Pathophysiological and Clinical Review. Top Companion Anim Med 2021; 43:100516. [PMID: 33556640 DOI: 10.1016/j.tcam.2021.100516] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2020] [Revised: 01/22/2021] [Accepted: 01/29/2021] [Indexed: 12/11/2022]
Abstract
Sleep is a fundamental process in mammals, including domestic dogs. Disturbances in sleep affect physiological functions like cognitive and physical performance, immune response, pain sensation and increase the risk of diseases. In dogs, sleep can be affected by several conditions, with narcolepsy, REM sleep behavior disorder and sleep breathing disorders being the most frequent causes. Furthermore, sleep disturbances can be a symptom of other primary diseases where they can contribute to the worsening of clinical signs. This review describes reciprocally interacting sleep and wakefulness promoting systems and how their dysfunction can explain the pathophysiological mechanisms of sleep disorders. Additionally, this work discusses the clinical characteristics, diagnostic tools and available treatments for these disorders while highlighting areas in where further studies are needed so as to improve their treatment and prevention.
Collapse
|
13
|
Lindström M, Schinkelshoek M, Tienari PJ, Kukkonen JP, Renkonen R, Fronczek R, Lammers GJ, Itkonen O. Orexin-A measurement in narcolepsy: A stability study and a comparison of LC-MS/MS and immunoassays. Clin Biochem 2021; 90:34-39. [PMID: 33539807 DOI: 10.1016/j.clinbiochem.2021.01.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 01/18/2021] [Accepted: 01/19/2021] [Indexed: 11/30/2022]
Abstract
BACKGROUND Orexin-A and -B are neuropeptides involved in sleep-wake regulation. In human narcolepsy type 1, this cycle is disrupted due to loss of orexin-producing neurons in the hypothalamus. Cerebrospinal fluid (CSF) orexin-A measurement is used in the diagnosis of narcolepsy type 1. Currently available immunoassays may lack specificity for accurate orexin quantification. We developed and validated a liquid chromatography mass spectrometry assay (LC-MS/MS) for CSF orexin-A and B. METHODS We used CSF samples from narcolepsy type 1 (n = 22) and type 2 (n = 6) and non-narcoleptic controls (n = 44). Stable isotope-labeled orexin-A and -B internal standards were added to samples before solid-phase extraction and quantification by LC-MS/MS. The samples were also assayed by commercial radioimmunoassay (RIA, n = 42) and enzymatic immunoassay (EIA, n = 72) kits. Stability of orexins in CSF was studied for 12 months. RESULTS Our assay has a good sensitivity (10 pmol/L = 35 pg/mL) and a wide linear range (35-3500 pg/mL). Added orexin-A and -B were stable in CSF for 12 and 3 months, respectively, when frozen. The median orexin-A concentration in CSF from narcolepsy type 1 patients was <35 pg/mL (range < 35-131 pg/mL), which was lower than that in CSF from control individuals (98 pg/mL, range < 35-424 pg/mL). Orexin-A concentrations determined using our LC-MS/MS assay were five times lower than those measured with a commercial RIA. Orexin-B concentrations were undetectable. CONCLUSIONS Orexin-A concentrations measured by our LC-MS/MS assay were lower in narcolepsy type 1 patients as compared to controls. RIA yielded on average higher concentrations than LC-MS/MS.
Collapse
Affiliation(s)
- Mikael Lindström
- HUS Diagnostic Center, University of Helsinki and Helsinki University Hospital, Helsinki, Finland.
| | - Mink Schinkelshoek
- Department of Neurology, Leiden University Medical Center, Leiden, The Netherlands; Sleep-Wake Centre, Stichting Epilepsie Instellingen Nederland (SEIN), Heemstede, The Netherlands
| | - Pentti J Tienari
- HUS Neurocenter, Helsinki University Hospital, Helsinki, Finland; Translational Immunology Research Program, Faculty of Medicine, University of Helsinki, Finland
| | - Jyrki P Kukkonen
- Department of Pharmacology, Institute of Biomedicine, University of Helsinki, Helsinki, Finland
| | - Risto Renkonen
- HUS Diagnostic Center, University of Helsinki and Helsinki University Hospital, Helsinki, Finland; Transplantation Laboratory, Haartman Institute, University of Helsinki, Helsinki, Finland
| | - Rolf Fronczek
- Department of Neurology, Leiden University Medical Center, Leiden, The Netherlands; Sleep-Wake Centre, Stichting Epilepsie Instellingen Nederland (SEIN), Heemstede, The Netherlands
| | - Gert Jan Lammers
- Department of Neurology, Leiden University Medical Center, Leiden, The Netherlands; Sleep-Wake Centre, Stichting Epilepsie Instellingen Nederland (SEIN), Heemstede, The Netherlands
| | - Outi Itkonen
- HUS Diagnostic Center, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| |
Collapse
|
14
|
|
15
|
Abstract
Excessive daytime sleepiness (EDS) is related to medical and social problems, including mental disorders, physical diseases, poor quality of life, and so forth. According to the International Classification of Sleep Disorders, Third Edition, diseases that result from EDS are narcolepsy type 1, narcolepsy type 2, idiopathic hypersomnia, hypersomnia due to a medical disorder, and others. EDS is usually treated using amphetamine-like central nervous system stimulants or modafinil and its R-enantiomer, armodafinil, wake-promoting compounds unrelated to amphetamines; a variety of new drugs are under development. The side effects of some stimulants are potent and careful selection and management are required.
Collapse
Affiliation(s)
- Shinichi Takenoshita
- Sleep and Circadian Neurobiology Laboratory, Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford University, Palo Alto, CA, USA
| | - Seiji Nishino
- Sleep and Circadian Neurobiology Laboratory, Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford University, Palo Alto, CA, USA.
| |
Collapse
|
16
|
Reicher V, Kis A, Simor P, Bódizs R, Gombos F, Gácsi M. Repeated afternoon sleep recordings indicate first‐night‐effect‐like adaptation process in family dogs. J Sleep Res 2020; 29:e12998. [DOI: 10.1111/jsr.12998] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 01/23/2020] [Accepted: 01/26/2020] [Indexed: 12/18/2022]
Affiliation(s)
- Vivien Reicher
- Department of Ethology Institute of Biology Eötvös Loránd University Budapest Hungary
| | - Anna Kis
- Research Centre for Natural Sciences Institute of Cognitive Neuroscience and Psychology Budapest Hungary
| | - Péter Simor
- Institute of Psychology Eötvös Loránd University Budapest Hungary
- Institute of Behavioural Sciences Semmelweis University Budapest Hungary
| | - Róbert Bódizs
- Institute of Behavioural Sciences Semmelweis University Budapest Hungary
- Juhász Pál Epilepsy Center National Institute of Clinical Neuroscience Budapest Hungary
| | - Ferenc Gombos
- Department of General Psychology Pázmány Péter Catholic University Budapest Hungary
- MTA‐PPKE Adolescent Development Research Group Budapest Hungary
| | - Márta Gácsi
- Department of Ethology Institute of Biology Eötvös Loránd University Budapest Hungary
- MTA‐ELTE Comparative Ethology Research Group Budapest Hungary
| |
Collapse
|
17
|
Mari L, Shea A. Symptomatic Narcolepsy/Cataplexy in a Dog with Brainstem Meningoencephalitis of Unknown Origin. J Am Anim Hosp Assoc 2020; 56:e56201. [PMID: 31961221 DOI: 10.5326/jaaha-ms-6892] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A 4 yr old, intact female cocker spaniel was presented for investigation of acute, progressive lethargy/hypersomnia; vestibular signs; and cataplexy. A narcolepsy-cataplexy episode with associated hypertension and bradycardia was triggered during examination. There was no evidence of arrhythmia on electrocardiography during the episode. Hematology, serum biochemistry, and thoracic and abdominal imaging were unremarkable. MRI of the brain and cerebrospinal fluid analysis were compatible with meningoencephalitis of unknown origin affecting the mesencephalon, pons and rostral medulla oblongata. The dog was started on immunosuppressive treatment with prednisolone and cytosine arabinoside, which was subsequently switched to cyclosporine. Narcolepsy-cataplexy episodes could initially still be triggered by offering food; however, they gradually became shorter and less frequent until they completely subsided along with all other clinical signs after 3 wk. No relapse occurred over a 32 mo follow-up period from the diagnosis. Repeated MRI revealed marked reduction in the lesion size; cerebrospinal fluid analysis revealed no abnormalities. Although very rare, symptomatic narcolepsy/cataplexy can occur in dogs and can be secondary to brainstem encephalitis. Cardiovascular changes can occur in association with narcolepsy/cataplexy and should be considered when dealing with patients presenting with these specific clinical signs.
Collapse
Affiliation(s)
- Lorenzo Mari
- From the Neurology/Neurosurgery Service, Centre for Small Animal Studies, Animal Health Trust, Suffolk, United Kingdom
| | - Anita Shea
- From the Neurology/Neurosurgery Service, Centre for Small Animal Studies, Animal Health Trust, Suffolk, United Kingdom
| |
Collapse
|
18
|
Ravel JM, Mignot EJM. [Narcolepsy: From the discovery of a wake promoting peptide to autoimmune T cell biology and molecular mimicry with flu epitopes]. Biol Aujourdhui 2019; 213:87-108. [PMID: 31829930 DOI: 10.1051/jbio/2019026] [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: 10/16/2019] [Indexed: 11/14/2022]
Abstract
Narcolepsy-cataplexy was first described in the late 19th century in Germany and France. Prevalence was established to be 0.05 % and a canine model was discovered in the 1970s. In 1983, a Japanese study found that all patients carried HLA-DR2, suggesting autoimmunity as the cause of the disease. Studies in the canine model established that dopaminergic stimulation underlies anti-narcoleptic action of psychostimulants, while antidepressants were found to suppress cataplexy through adrenergic reuptake inhibition. No HLA association was found in canines. A linkage study initiated in 1988 revealed in hypocretin (orexin) receptor two mutations as the cause of canine narcolepsy in 1999. In 1992, studies on African Americans showed that DQ0602 was a better marker than DR2 across all ethnic groups. In 2000, hypocretin-1/orexin A levels were measured in the cerebrospinal fluid (CSF) and found to be undetectable in most patients, establishing hypocretin deficiency as the cause of narcolepsy. Decreased CSF hypocretin-1 was then found to be secondary to the loss of the 70,000 neurons producing hypocretin in the hypothalamus, suggesting immune destruction of these cells as the cause of the disease. Additional genetic studies, notably genome wide associations (GWAS), found multiple genetic predisposing factors for narcolepsy. These were almost all involved in other autoimmune diseases, although a strong and unique association with T cell receptor (TCR) alpha and beta loci were observed. Nonetheless, all attempts to demonstrate presence of autoantibodies against hypocretin cells in narcolepsy failed, and the presumed autoimmune cause remained unproven. In 2009, association with strep throat infections were found, and narcolepsy onsets were found to occur more frequently in spring and summer, suggesting upper away infections as triggers. Following reports that narcolepsy cases were triggered by vaccinations and infections against influenza A 2009 pH1N1, a new pandemic strain that erupted in 2009, molecular mimicry with influenza A virus was suggested in 2010. This hypothesis was later confirmed by peptide screening showing higher activity of CD4+ T cell reactivity to a specific post-translationally amidated segment of hypocretin (HCRT-NH2) and cross-reactivity of specific TCRs with a pH1N1-specific segment of hemagglutinin that shares homology with HCRT-NH2. Strikingly, the most frequent TCR recognizing these antigens was found to carry sequences containing TRAJ24 or TRVB4-2, segments modulated by narcolepsy-associated genetic polymorphisms. Cross-reactive CD4+ T cells with these cross-reactive TCRs likely subsequently recruit CD8+ T cells that are then involved in hypocretin cell destruction. Additional flu mimics are also likely to be discovered since narcolepsy existed prior to 2009. The work that has been conducted over the years on narcolepsy offers a unique perspective on the conduct of research on the etiopathogeny of a specific disease.
Collapse
Affiliation(s)
- Jean-Marie Ravel
- Stanford Center for Sleep Sciences and Medicine, Department of Psychiatry and Behavioral Medicine, Stanford University, 3615 Porter Drive, Palo Alto, CA, USA
| | - Emmanuel J M Mignot
- Stanford Center for Sleep Sciences and Medicine, Department of Psychiatry and Behavioral Medicine, Stanford University, 3615 Porter Drive, Palo Alto, CA, USA
| |
Collapse
|
19
|
Abstract
Narcolepsy is the most common neurological cause of chronic sleepiness. The discovery about 20 years ago that narcolepsy is caused by selective loss of the neurons producing orexins (also known as hypocretins) sparked great advances in the field. Here, we review the current understanding of how orexin neurons regulate sleep-wake behaviour and the consequences of the loss of orexin neurons. We also summarize the developing evidence that narcolepsy is an autoimmune disorder that may be caused by a T cell-mediated attack on the orexin neurons and explain how these new perspectives can inform better therapeutic approaches.
Collapse
Affiliation(s)
- Carrie E Mahoney
- Department of Neurology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA
| | - Andrew Cogswell
- Department of Neurological Sciences, Rush University Medical Center, Chicago, IL, USA
| | - Igor J Koralnik
- Department of Neurological Sciences, Rush University Medical Center, Chicago, IL, USA
| | - Thomas E Scammell
- Department of Neurology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA.
| |
Collapse
|
20
|
Naganuma F, Bandaru SS, Absi G, Mahoney CE, Scammell TE, Vetrivelan R. Melanin-concentrating hormone neurons contribute to dysregulation of rapid eye movement sleep in narcolepsy. Neurobiol Dis 2018; 120:12-20. [PMID: 30149182 PMCID: PMC6195361 DOI: 10.1016/j.nbd.2018.08.012] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Revised: 08/02/2018] [Accepted: 08/23/2018] [Indexed: 12/22/2022] Open
Abstract
The lateral hypothalamus contains neurons producing orexins that promote wakefulness and suppress REM sleep as well as neurons producing melanin-concentrating hormone (MCH) that likely promote REM sleep. Narcolepsy with cataplexy is caused by selective loss of the orexin neurons, and the MCH neurons appear unaffected. As the orexin and MCH systems exert opposing effects on REM sleep, we hypothesized that imbalance in this REM sleep-regulating system due to activity in the MCH neurons may contribute to the striking REM sleep dysfunction characteristic of narcolepsy. To test this hypothesis, we chemogenetically activated the MCH neurons and pharmacologically blocked MCH signaling in a murine model of narcolepsy and studied the effects on sleep-wake behavior and cataplexy. To chemoactivate MCH neurons, we injected an adeno-associated viral vector containing the hM3Dq stimulatory DREADD into the lateral hypothalamus of orexin null mice that also express Cre recombinase in the MCH neurons (MCH-Cre::OX-KO mice) and into control MCH-Cre mice with normal orexin expression. In both lines of mice, activation of MCH neurons by clozapine-N-oxide (CNO) increased rapid eye movement (REM) sleep without altering other states. In mice lacking orexins, activation of the MCH neurons also increased abnormal intrusions of REM sleep manifest as cataplexy and short latency transitions into REM sleep (SLREM). Conversely, a MCH receptor 1 antagonist, SNAP 94847, almost completely eliminated SLREM and cataplexy in OX-KO mice. These findings affirm that MCH neurons promote REM sleep under normal circumstances, and their activity in mice lacking orexins likely triggers abnormal intrusions of REM sleep into non-REM sleep and wake, resulting in the SLREM and cataplexy characteristic of narcolepsy.
Collapse
Affiliation(s)
- Fumito Naganuma
- Department of Neurology, Beth Israel Deaconess Medical Center and Division of Sleep Medicine, Harvard Medical School, Boston MA-02215, USA; Division of Pharmacology, Faculty of Medicine, Tohoku Medical and Pharmaceutical University, 1-15-1, Fukumuro, Miyagino-ku, Sendai 983-8536, Japan
| | - Sathyajit S Bandaru
- Department of Neurology, Beth Israel Deaconess Medical Center and Division of Sleep Medicine, Harvard Medical School, Boston MA-02215, USA
| | - Gianna Absi
- Department of Neurology, Beth Israel Deaconess Medical Center and Division of Sleep Medicine, Harvard Medical School, Boston MA-02215, USA
| | - Carrie E Mahoney
- Department of Neurology, Beth Israel Deaconess Medical Center and Division of Sleep Medicine, Harvard Medical School, Boston MA-02215, USA
| | - Thomas E Scammell
- Department of Neurology, Beth Israel Deaconess Medical Center and Division of Sleep Medicine, Harvard Medical School, Boston MA-02215, USA
| | - Ramalingam Vetrivelan
- Department of Neurology, Beth Israel Deaconess Medical Center and Division of Sleep Medicine, Harvard Medical School, Boston MA-02215, USA.
| |
Collapse
|
21
|
Takahashi T, Noriaki S, Matsumura M, Li C, Takahashi K, Nishino S. Advances in pharmaceutical treatment options for narcolepsy. Expert Opin Orphan Drugs 2018. [DOI: 10.1080/21678707.2018.1521267] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Tatsunori Takahashi
- Stanford University Sleep and Circadian Neurobiology Laboratory, Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Palo Alto, CA, USA
| | - Sakai Noriaki
- Stanford University Sleep and Circadian Neurobiology Laboratory, Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Palo Alto, CA, USA
| | - Mari Matsumura
- Stanford University Sleep and Circadian Neurobiology Laboratory, Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Palo Alto, CA, USA
| | - Chenyu Li
- Stanford University Sleep and Circadian Neurobiology Laboratory, Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Palo Alto, CA, USA
| | - Kayo Takahashi
- Stanford University Sleep and Circadian Neurobiology Laboratory, Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Palo Alto, CA, USA
| | - Seiji Nishino
- Stanford University Sleep and Circadian Neurobiology Laboratory, Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Palo Alto, CA, USA
| |
Collapse
|
22
|
|
23
|
Nonclinical data supporting orphan medicinal product designations: lessons from rare neurological conditions. Drug Discov Today 2018; 23:26-48. [DOI: 10.1016/j.drudis.2017.09.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 09/01/2017] [Accepted: 09/27/2017] [Indexed: 12/14/2022]
|
24
|
Hines MT. Clinical Approach to Commonly Encountered Problems. EQUINE INTERNAL MEDICINE 2018. [PMCID: PMC7158300 DOI: 10.1016/b978-0-323-44329-6.00007-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
|
25
|
Abstract
Excessive daytime sleepiness (EDS) is related to medical and social problems, including mental disorders, physical diseases, poor quality of life, and so forth. According to the International Classification of Sleep Disorders, Third Edition, diseases that result from EDS are narcolepsy type 1, narcolepsy type 2, idiopathic hypersomnia, hypersomnia due to a medical disorder, and others. EDS is usually treated using amphetamine-like central nervous system stimulants or modafinil and its R-enantiomer, armodafinil, wake-promoting compounds unrelated to amphetamines; a variety of new drugs are under development. The side effects of some stimulants are potent and careful selection and management are required.
Collapse
|
26
|
Vassalli A, Li S, Tafti M. Comment on "Antibodies to influenza nucleoprotein cross-react with human hypocretin receptor 2". Sci Transl Med 2016; 7:314le2. [PMID: 26582896 DOI: 10.1126/scitranslmed.aad2353] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Did hypocretin receptor 2 autoantibodies cause narcolepsy with hypocretin deficiency in Pandemrix-vaccinated children, as suggested by Ahmed et al.? Using newly developed mouse models to report and inactivate hypocretin receptor expression, Vassalli et al. now show that hypocretin neurons (whose loss causes narcolepsy) do not express hypocretin autoreceptors, raising questions to the interpretation of Ahmed et al.'s findings.
Collapse
Affiliation(s)
- Anne Vassalli
- Center for Integrative Genomics, University of Lausanne, CH-1015 Lausanne, Switzerland.
| | - Sha Li
- Center for Integrative Genomics, University of Lausanne, CH-1015 Lausanne, Switzerland
| | - Mehdi Tafti
- Center for Integrative Genomics, University of Lausanne, CH-1015 Lausanne, Switzerland.
| |
Collapse
|
27
|
Abstract
Much of the understanding of the hypocretin/orexin (HCRT/OX) system in sleep-wake regulation came from narcolepsy-cataplexy research. The neuropeptides hypocretin-1 and -2/orexin-A and -B (HCRT-1 and -2/OX-A and -B, respectively), as we know, are intimately involved in the regulation wakefulness. The HCRT/OX system regulates sleep-wake control through complex interactions between monoaminergic/cholinergic (wake-promoting) and gamma-aminobutyric acid-ergic (sleep-promoting) neuronal systems. Deficiency of HCRT/OX results in loss of sleep-wake control or stability with consequent unstable transitions between wakefulness to nonrapid eye movement and rapid eye movement sleep. This manifests clinically as abnormal daytime sleepiness with sleep attacks and cataplexy. Research on the development of HCRT/OX agonists and antagonists for the treatment of sleep disorders has dramatically increased with the US Food and Drug Administration approval of the first-in-class dual HCRT/OX receptor antagonist for the treatment of insomnia. This review focuses on the origin, mechanisms of HCRT/OX receptors, clinical progress, and applications for the treatment of sleep disorders.
Collapse
Affiliation(s)
- Matthew Chow
- Department of Psychiatry and Behavioral Sciences, Division of Sleep Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - Michelle Cao
- Department of Psychiatry and Behavioral Sciences, Division of Sleep Medicine, Stanford University School of Medicine, Stanford, CA, USA
| |
Collapse
|
28
|
Black SW, Yamanaka A, Kilduff TS. Challenges in the development of therapeutics for narcolepsy. Prog Neurobiol 2015; 152:89-113. [PMID: 26721620 DOI: 10.1016/j.pneurobio.2015.12.002] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Revised: 11/14/2015] [Accepted: 12/04/2015] [Indexed: 01/19/2023]
Abstract
Narcolepsy is a neurological disorder that afflicts 1 in 2000 individuals and is characterized by excessive daytime sleepiness and cataplexy-a sudden loss of muscle tone triggered by positive emotions. Features of narcolepsy include dysregulation of arousal state boundaries as well as autonomic and metabolic disturbances. Disruption of neurotransmission through the hypocretin/orexin (Hcrt) system, usually by degeneration of the HCRT-producing neurons in the posterior hypothalamus, results in narcolepsy. The cause of Hcrt neurodegeneration is unknown but thought to be related to autoimmune processes. Current treatments for narcolepsy are symptomatic, including wake-promoting therapeutics that increase presynaptic dopamine release and anticataplectic agents that activate monoaminergic neurotransmission. Sodium oxybate is the only medication approved by the US Food and Drug Administration that alleviates both sleep/wake disturbances and cataplexy. Development of therapeutics for narcolepsy has been challenged by historical misunderstanding of the disease, its many disparate symptoms and, until recently, its unknown etiology. Animal models have been essential to elucidating the neuropathology underlying narcolepsy. These models have also aided understanding the neurobiology of the Hcrt system, mechanisms of cataplexy, and the pharmacology of narcolepsy medications. Transgenic rodent models will be critical in the development of novel therapeutics for the treatment of narcolepsy, particularly efforts directed to overcome challenges in the development of hypocretin replacement therapy.
Collapse
Affiliation(s)
- Sarah Wurts Black
- Center for Neuroscience, Biosciences Division, SRI International, Menlo Park, CA 94025, USA
| | - Akihiro Yamanaka
- Research Institute of Environmental Medicine, Nagoya University, Nagoya 464-8601, Japan
| | - Thomas S Kilduff
- Center for Neuroscience, Biosciences Division, SRI International, Menlo Park, CA 94025, USA.
| |
Collapse
|
29
|
Maruyama T, Matsumura M, Sakai N, Nishino S. The pathogenesis of narcolepsy, current treatments and prospective therapeutic targets. Expert Opin Orphan Drugs 2015. [DOI: 10.1517/21678707.2016.1117973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
30
|
Gilmore KM, Greer KA. Why is the dog an ideal model for aging research? Exp Gerontol 2015; 71:14-20. [PMID: 26325590 DOI: 10.1016/j.exger.2015.08.008] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Revised: 08/17/2015] [Accepted: 08/18/2015] [Indexed: 12/22/2022]
Abstract
With many caveats to the traditional vertebrate species pertaining to biogerontology investigations, it has been suggested that a most informative model is the one which: 1) examines closely related species, or various members of the same species with naturally occurring lifespan variation, 2) already has adequate medical procedures developed, 3) has a well annotated genome, 4) does not require artificial housing, and can live in its natural environment while being investigated, and 5) allows considerable information to be gathered within a relatively short period of time. The domestic dog unsurprisingly fits each criterion mentioned. The dog has already become a key model system in which to evaluate surgical techniques and novel medications because of the remarkable similarity between human and canine conditions, treatments, and response to therapy. The dog naturally serves as a disease model for study, obviating the need to construct artificial genetically modified examples of disease. Just as the dog offers a natural model for human conditions and diseases, simple observation leads to the conclusion that the canine aging phenotype also mimics that of the human. Genotype information, biochemical information pertaining to the GH/IGF-1 pathway, and some limited longitudinal investigations have begun the establishment of the domestic dog as a model of aging. Although we find that dogs indeed are a model to study aging and there are many independent pieces of canine aging data, there are many more "open" areas, ripe for investigation.
Collapse
Affiliation(s)
- Keiva M Gilmore
- Prairie View A&M University, PO Box 512, MS 2210, Prairie View, TX 77446, United States
| | - Kimberly A Greer
- Prairie View A&M University, PO Box 512, MS 2210, Prairie View, TX 77446, United States.
| |
Collapse
|
31
|
Nishino S, Sato M, Matsumura M, Kanbayashi T. Narcolepsy–Cataplexy Syndrome and Symptomatic Hypersomnia. Sleep Med 2015. [DOI: 10.1007/978-1-4939-2089-1_26] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
32
|
Abstract
Historically, the dog played an important role as a laboratory animal in biomedical research. Although numbers are declining, the use of dogs continues to be common in pharmacokinetics and cardiovascular studies. The normal biology of the dog as both a laboratory and a companion animal has been well studied and reference values are presented here as a clinical and experimental resource. This provides the necessary background to discuss the spontaneous diseases, including infectious and neoplastic conditions, prevalent in purpose bred as well as random source dogs used in biomedical research. In addition, diseases and conditions that arise secondary to the housing and experimental manipulation of dogs is discussed with emphasis on treatment and prevention.
Collapse
|
33
|
Barloese M, Jennum P, Lund N, Knudsen S, Gammeltoft S, Jensen R. Reduced CSF hypocretin-1 levels are associated with cluster headache. Cephalalgia 2014; 35:869-76. [DOI: 10.1177/0333102414562971] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Accepted: 11/10/2014] [Indexed: 01/03/2023]
Abstract
Background Cluster headache (CH) is a debilitating disorder characterized by unilateral, severe pain attacks with accompanying autonomic symptoms, often waking the patient from sleep. As it exhibits strong chronobiological traits and genetic studies have suggested a link with the hypocretin (HCRT) system, the objective of this study was to investigate HCRT-1 in CH patients. Methods Cerebrospinal fluid HCRT-1 concentration was measured in 12 chronic and 14 episodic CH patients during an active bout, and in 27 healthy controls. The patients were well characterized and clinical features compared to the HCRT concentration. Results We found significantly lower HCRT levels both in chronic ( p = 0.0221) and episodic CH ( p = 0.0005) patients compared with controls. No significant relationship was found with other clinical features. Conclusions This is the first report of significantly reduced HCRT concentrations in CH patients. We speculate that decreased HCRT may reflect insufficient antinociceptive activity of the hypothalamus. The mechanism of the antinociceptive effect of HCRT is not known and requires further investigation. This study supports the hypothesis of a connection between arousal regulation and CH.
Collapse
Affiliation(s)
- Mads Barloese
- Danish Headache Center, Dept. of Neurology, Glostrup Hospital, University of Copenhagen, Denmark
| | - Poul Jennum
- Danish Center for Sleep Medicine, Dept. of Neurophysiology, Glostrup Hospital, University of Copenhagen, Denmark
| | - Nunu Lund
- Danish Headache Center, Dept. of Neurology, Glostrup Hospital, University of Copenhagen, Denmark
| | - Stine Knudsen
- Danish Center for Sleep Medicine, Dept. of Neurophysiology, Glostrup Hospital, University of Copenhagen, Denmark
- Clinical Biochemistry Section, Dept. of Diagnostics, Glostrup Hospital, University of Copenhagen, Denmark
| | - Steen Gammeltoft
- Norwegian Resource Center for ADHD, TS and Narcolepsy, University Hospital of Oslo, Norway
| | - Rigmor Jensen
- Danish Headache Center, Dept. of Neurology, Glostrup Hospital, University of Copenhagen, Denmark
| |
Collapse
|
34
|
Krämer S, Goldammer U, Sindern E. Möbius-Syndrom und Narkolepsie. DER NERVENARZT 2014; 85:1569-72. [DOI: 10.1007/s00115-014-4174-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
35
|
Chen Q, de Lecea L, Hu Z, Gao D. The hypocretin/orexin system: an increasingly important role in neuropsychiatry. Med Res Rev 2014; 35:152-97. [PMID: 25044006 DOI: 10.1002/med.21326] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Hypocretins, also named as orexins, are excitatory neuropeptides secreted by neurons specifically located in lateral hypothalamus and perifornical areas. Orexinergic fibers are extensively distributed in various brain regions and involved in a number of physiological functions, such as arousal, cognition, stress, appetite, and metabolism. Arousal is the most important function of orexin system as dysfunction of orexin signaling leads to narcolepsy. In addition to narcolepsy, orexin dysfunction is associated with serious neural disorders, including addiction, depression, and anxiety. However, some results linking orexin with these disorders are still contradictory, which may result from differences of detection methods or the precision of tools used in measurements; strategies targeted to orexin system (e.g., antagonists to orexin receptors, gene delivery, and cell transplantation) are promising new tools for treatment of neuropsychiatric disorders, though studies are still in a stage of preclinical or clinical research.
Collapse
Affiliation(s)
- Quanhui Chen
- Department of Physiology, Third Military Medical University, Chongqing 400038, China; Department of Sleep and Psychology, Institute of Surgery Research, Daping Hospital, Third Military Medical University, Chongqing 400038, China
| | | | | | | |
Collapse
|
36
|
Abstract
Although narcolepsy was first described in the late nineteenth century in Germany and France, much of the research on this disorder has been conducted at Stanford University, starting with Drs. William C. Dement and Christian Guilleminault in the 1970s. The prevalence of narcolepsy was established, and a canine model discovered. Following the finding in Japan that almost all patients with narcolepsy carry a specific HLA subtype, HLA-DR2, Hugh Mac Devitt, F. Carl Grumet, and Larry Steinman initiated immunological studies, but results were generally negative. Using the narcoleptic canines, Dr. Nishino and I established that stimulants increased wakefulness by stimulating dopaminergic transmission while antidepressants suppress cataplexy via adrenergic reuptake inhibition. A linkage study was initiated with Dr. Grumet in 1988, and after 10 years of work, the canine narcolepsy gene was cloned by in 1999 and identified as the hypocretin (orexin) receptor 2. In 1992, studying African Americans, we also found that DQ0602 rather than DR2 was a better marker for narcolepsy across all ethnic groups. In 2000, Dr. Nishino and I, in collaboration with Dr. Lammers in the Netherlands, found that hypocretin 1 levels in the cerebrospinal fluid (CSF) were undetectable in most cases, establishing hypocretin deficiency as the cause of narcolepsy. Pursuing this research, our and Dr. Siegel's group, examining postmortem brains, found that the decreased CSF hypocretin 1 was secondary to the loss the 70,000 neurons producing hypocretin in the hypothalamus. This finding revived the autoimmune hypothesis but attempts at demonstrating immune targeting of hypocretin cells failed until 2013. At this date, Dr. Elisabeth Mellins and I discovered that narcolepsy is characterized by the presence of autoreactive CD4(+) T cells to hypocretin fragments when presented by DQ0602. Following reports that narcolepsy cases were triggered by vaccinations and infections against influenza A 2009 pH1N1, a new pandemic strain that erupted in 2009, our groups also established that a small epitope of pH1N1 resembles hypocretin and is likely involved in molecular mimicry. Although much remains to be done, these achievements, establishing hypocretin deficiency as the cause of narcolepsy, demonstrating its autoimmune basis, and showing molecular mimicry between hypocretin and sequences derived from a pandemic strain of influenza, are likely to remain classics in human immunology.
Collapse
Affiliation(s)
- Emmanuel J M Mignot
- Stanford University Center for Sleep Sciences, 3165 Porter Drive, #2178, Palo Alto, CA, 94304, USA,
| |
Collapse
|
37
|
Schöne C, Apergis-Schoute J, Sakurai T, Adamantidis A, Burdakov D. Coreleased orexin and glutamate evoke nonredundant spike outputs and computations in histamine neurons. Cell Rep 2014; 7:697-704. [PMID: 24767990 PMCID: PMC4022832 DOI: 10.1016/j.celrep.2014.03.055] [Citation(s) in RCA: 138] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2013] [Revised: 02/05/2014] [Accepted: 03/13/2014] [Indexed: 12/28/2022] Open
Abstract
Stable wakefulness requires orexin/hypocretin neurons (OHNs) and OHR2 receptors. OHNs sense diverse environmental cues and control arousal accordingly. For unknown reasons, OHNs contain multiple excitatory transmitters, including OH peptides and glutamate. To analyze their cotransmission within computational frameworks for control, we optogenetically stimulated OHNs and examined resulting outputs (spike patterns) in a downstream arousal regulator, the histamine neurons (HANs). OHR2s were essential for sustained HAN outputs. OHR2-dependent HAN output increased linearly during constant OHN input, suggesting that the OHN→HANOHR2 module may function as an integral controller. OHN stimulation evoked OHR2-dependent slow postsynaptic currents, similar to midnanomolar OH concentrations. Conversely, glutamate-dependent output transiently communicated OHN input onset, peaking rapidly then decaying alongside OHN→HAN glutamate currents. Blocking glutamate-driven spiking did not affect OH-driven spiking and vice versa, suggesting isolation (low cross-modulation) of outputs. Therefore, in arousal regulators, cotransmitters may translate distinct features of OHN activity into parallel, nonredundant control signals for downstream effectors. Natural orexin release generates unique signatures of brain activity Unlike classical transmitter glutamate, orexin release produces enduring communication Orexin transmission requires a distinct neural firing code Orexin transmission is necessary for brain histamine neurons to integrate inputs
Collapse
Affiliation(s)
- Cornelia Schöne
- Division of Neurophysiology, MRC National Institute for Medical Research, London NW7 1AA, UK
| | | | - Takeshi Sakurai
- Department of Molecular Neuroscience and Integrative Physiology, Faculty of Medicine, Kanazawa University, Kanazawa, Ishikawa 920-8640, Japan; International Institute for Integrative Sleep Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Antoine Adamantidis
- Neurology Department, Bern University Hospital, 3010 Bern, Switzerland; Department of Psychiatry, McGill University, Montreal, QC H3A 0G4, Canada
| | - Denis Burdakov
- Division of Neurophysiology, MRC National Institute for Medical Research, London NW7 1AA, UK; MRC Centre for Developmental Neurobiology, King's College London, London WC2R 2LS, UK.
| |
Collapse
|
38
|
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: 114] [Impact Index Per Article: 11.4] [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.
Collapse
|
39
|
Hoyer D, Dürst T, Fendt M, Jacobson LH, Betschart C, Hintermann S, Behnke D, Cotesta S, Laue G, Ofner S, Legangneux E, Gee CE. Distinct effects of IPSU and suvorexant on mouse sleep architecture. Front Neurosci 2013; 7:235. [PMID: 24368893 PMCID: PMC3857892 DOI: 10.3389/fnins.2013.00235] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Accepted: 11/20/2013] [Indexed: 01/09/2023] Open
Abstract
Dual orexin receptor (OXR) antagonists (DORAs) such as almorexant, SB-649868, suvorexant (MK-4305), and filorexant (MK-6096), have shown promise for the treatment of insomnias and sleep disorders. Whether antagonism of both OX1R and OX2R is necessary for sleep induction has been a matter of some debate. Experiments using knockout mice suggest that it may be sufficient to antagonize only OX2R. The recent identification of an orally bioavailable, brain penetrant OX2R preferring antagonist 2-((1H-Indol-3-yl)methyl)-9-(4-methoxypyrimidin-2-yl)-2,9-diazaspiro[5.5]undecan-1-one (IPSU) has allowed us to test whether selective antagonism of OX2R may also be a viable strategy for induction of sleep. We previously demonstrated that IPSU and suvorexant increase sleep when dosed during the mouse active phase (lights off); IPSU inducing sleep primarily by increasing NREM sleep, suvorexant primarily by increasing REM sleep. Here, our goal was to determine whether suvorexant and IPSU affect sleep architecture independently of overall sleep induction. We therefore tested suvorexant (25 mg/kg) and IPSU (50 mg/kg) in mice during the inactive phase (lights on) when sleep is naturally more prevalent and when orexin levels are normally low. Whereas IPSU was devoid of effects on the time spent in NREM or REM, suvorexant substantially disturbed the sleep architecture by selectively increasing REM during the first 4 h after dosing. At the doses tested, suvorexant significantly decreased wake only during the first hour and IPSU did not affect wake time. These data suggest that OX2R preferring antagonists may have a reduced tendency for perturbing NREM/REM architecture in comparison with DORAs. Whether this effect will prove to be a general feature of OX2R antagonists vs. DORAs remains to be seen.
Collapse
Affiliation(s)
- Daniel Hoyer
- Neuroscience, Novartis Institutes for BioMedical Research Basel, Switzerland ; Department of Pharmacology and Therapeutics, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne Parkville, VIC, Australia
| | - Thomas Dürst
- Neuroscience, Novartis Institutes for BioMedical Research Basel, Switzerland
| | - Markus Fendt
- Neuroscience, Novartis Institutes for BioMedical Research Basel, Switzerland ; Department of Pharmacology and Therapeutics, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne Parkville, VIC, Australia
| | - Laura H Jacobson
- Neuroscience, Novartis Institutes for BioMedical Research Basel, Switzerland ; The Florey Institute of Neuroscience and Mental Health, The University of Melbourne Parkville, VIC, Australia
| | - Claudia Betschart
- Global Discovery Chemistry, Novartis Institutes for BioMedical Research Basel, Switzerland
| | - Samuel Hintermann
- Global Discovery Chemistry, Novartis Institutes for BioMedical Research Basel, Switzerland
| | - Dirk Behnke
- Global Discovery Chemistry, Novartis Institutes for BioMedical Research Basel, Switzerland
| | - Simona Cotesta
- Global Discovery Chemistry, Novartis Institutes for BioMedical Research Basel, Switzerland
| | - Grit Laue
- Metabolism and Pharmacokinetics, Novartis Institutes for BioMedical Research Basel, Switzerland
| | - Silvio Ofner
- Global Discovery Chemistry, Novartis Institutes for BioMedical Research Basel, Switzerland
| | - Eric Legangneux
- Translational Medicine, Novartis Institutes for BioMedical Research Basel, Switzerland
| | - Christine E Gee
- Neuroscience, Novartis Institutes for BioMedical Research Basel, Switzerland ; Center for Molecular Neuroscience Hamburg, Institute for Synaptic Physiology Hamburg, Germany
| |
Collapse
|
40
|
Luca G, Haba-Rubio J, Dauvilliers Y, Lammers GJ, Overeem S, Donjacour CE, Mayer G, Javidi S, Iranzo A, Santamaria J, Peraita-Adrados R, Hor H, Kutalik Z, Plazzi G, Poli F, Pizza F, Arnulf I, Lecendreux M, Bassetti C, Mathis J, Heinzer R, Jennum P, Knudsen S, Geisler P, Wierzbicka A, Feketeova E, Pfister C, Khatami R, Baumann C, Tafti M. Clinical, polysomnographic and genome-wide association analyses of narcolepsy with cataplexy: a European Narcolepsy Network study. J Sleep Res 2013; 22:482-95. [PMID: 23496005 DOI: 10.1111/jsr.12044] [Citation(s) in RCA: 151] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Accepted: 01/17/2013] [Indexed: 11/30/2022]
Affiliation(s)
- Gianina Luca
- Center for Integrative Genomics (CIG); University of Lausanne; Lausanne Switzerland
| | - José Haba-Rubio
- Center for Investigation and Research in Sleep (CIRS); Centre Hospitalier Universitaire Vaudois (CHUV); Lausanne Switzerland
| | - Yves Dauvilliers
- INSERM-1061; Montpellier France
- Department of Neurology; National Reference Network for Orphan Diseases (Narcolepsy and Idiopathic Hypersomnia); Gui-de-Chauliac Hospital; Montpellier France
| | - Gert-Jan Lammers
- Department of Neurology and Clinical Neurophysiology; Leiden University Medical Centre; Leiden the Netherlands
| | | | - Claire E. Donjacour
- Department of Neurology and Clinical Neurophysiology; Leiden University Medical Centre; Leiden the Netherlands
| | - Geert Mayer
- Hephata-Clinic for Neurology; Schwalmstadt-Treysa Germany
| | - Sirous Javidi
- Hephata-Clinic for Neurology; Schwalmstadt-Treysa Germany
| | - Alex Iranzo
- Neurology Service; Hospital Clinic; Barcelona Spain
| | | | - Rosa Peraita-Adrados
- Sleep and Epilepsy Unit - Clinical Neurophysiology Department; Gregorio Marañón University Hospital; Madrid Spain
| | - Hyun Hor
- Center for Integrative Genomics (CIG); University of Lausanne; Lausanne Switzerland
| | - Zoltan Kutalik
- Department of Medical Genetics; University of Lausanne; Lausanne Switzerland
- Swiss Institute of Bioinformatics; Lausanne Switzerland
| | - Giuseppe Plazzi
- Department of Neurological Sciences; University of Bologna/IRCCS; Istituto delle Scienze Neurologiche di; Bologna Italy
| | - Francesca Poli
- Department of Neurological Sciences; University of Bologna/IRCCS; Istituto delle Scienze Neurologiche di; Bologna Italy
| | - Fabio Pizza
- Department of Neurological Sciences; University of Bologna/IRCCS; Istituto delle Scienze Neurologiche di; Bologna Italy
| | - Isabelle Arnulf
- National Reference Network for Orphan Diseases (Narcolepsy and Idiopathic Hypersomnia); Sleep Disorders Unit; Pitié-Salpêtrière Hospital; Paris France
| | - Michel Lecendreux
- Pediatric Sleep Center; National Reference Network for Orphan Diseases (Narcolepsy and Idiopathic Hypersomnia); Robert-Debré Hospital; Paris France
| | - Claudio Bassetti
- Department of Neurology; Inselspital, Bern University Hospital and University of Bern; Bern Switzerland
| | - Johannes Mathis
- Department of Neurology; Inselspital, Bern University Hospital and University of Bern; Bern Switzerland
| | - Raphael Heinzer
- Center for Investigation and Research in Sleep (CIRS); Centre Hospitalier Universitaire Vaudois (CHUV); Lausanne Switzerland
| | - Poul Jennum
- Department of Clinical Neurophysiology; University of Copenhagen; Glostrup Denmark
| | - Stine Knudsen
- Department of Clinical Neurophysiology; University of Copenhagen; Glostrup Denmark
| | - Peter Geisler
- Department of Psychiatry and Psychotherapy; Sleep Disorders and Research Center; University Hospital Regensburg; Regensburg Germany
| | - Aleksandra Wierzbicka
- Third Department of Psychiatry; Institute of Psychiatry and Neurology; Warsaw Poland
| | - Eva Feketeova
- Department of Neurology; Faculty of Medicine; Safarikiensis University and Louis Pasteur Faculty Hospital Kosice; Kosice Slovakia
| | - Corinne Pfister
- Center for Integrative Genomics (CIG); University of Lausanne; Lausanne Switzerland
| | - Ramin Khatami
- Sleep Medicine; Barmelweid Clinic; Barmelweid Switzerland
| | - Christian Baumann
- Department of Neurology; University Hospital Zurich; Zurich Switzerland
| | - Mehdi Tafti
- Center for Integrative Genomics (CIG); University of Lausanne; Lausanne Switzerland
- Center for Investigation and Research in Sleep (CIRS); Centre Hospitalier Universitaire Vaudois (CHUV); Lausanne Switzerland
| | | |
Collapse
|
41
|
Black SW, Morairty SR, Fisher SP, Chen TM, Warrier DR, Kilduff TS. Almorexant promotes sleep and exacerbates cataplexy in a murine model of narcolepsy. Sleep 2013; 36:325-36. [PMID: 23449602 DOI: 10.5665/sleep.2442] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
STUDY OBJECTIVES Humans with narcolepsy and orexin/ataxin-3 transgenic (TG) mice exhibit extensive, but incomplete, degeneration of hypo-cretin (Hcrt) neurons. Partial Hcrt cell loss also occurs in Parkinson disease and other neurologic conditions. Whether Hcrt antagonists such as almorexant (ALM) can exert an effect on the Hcrt that remains after Hcrt neurodegeneration has not yet been determined. The current study was designed to evaluate the hypnotic and cataplexy-inducing efficacy of a Hcrt antagonist in an animal model with low Hcrt tone and compare the ALM efficacy profile in the disease model to that produced in wild-type (WT) control animals. DESIGN Counterbalanced crossover study. SETTING Home cage. PATIENTS OR PARTICIPANTS Nine TG mice and 10 WT mice. INTERVENTIONS ALM (30, 100, 300 mg/kg), vehicle and positive control injections, dark/active phase onset. MEASUREMENTS AND RESULTS During the 12-h dark period after dosing, ALM exacerbated cataplexy in TG mice and increased nonrapid eye movement sleep with heightened sleep/wake fragmentation in both genotypes. ALM showed greater hypnotic potency in WT mice than in TG mice. The 100 mg/kg dose conferred maximal promotion of cataplexy in TG mice and maximal promotion of REM sleep in WT mice. In TG mice, ALM (30 mg/ kg) paradoxically induced a transient increase in active wakefulness. Core body temperature (Tb) decreased after acute Hcrt receptor blockade, but the reduction in Tb that normally accompanies the wake-to-sleep transition was blunted in TG mice. CONCLUSIONS These complex dose- and genotype-dependent interactions underscore the importance of effector mechanisms downstream from Hcrt receptors that regulate arousal state. Cataplexy promotion by ALM warrants cautious use of Hcrt antagonists in patient populations with Hcrt neurodegeneration, but may also facilitate the discovery of anticataplectic medications. CITATION Black SW; Morairty SR; Fisher SP; Chen TM; Warrier DR; Kilduff TS. Almorexant promotes sleep and exacerbates cataplexy in a murine model of narcolepsy. SLEEP 2013;36(3):325-336.
Collapse
|
42
|
Black SW, Morairty SR, Fisher SP, Chen TM, Warrier DR, Kilduff TS. Almorexant promotes sleep and exacerbates cataplexy in a murine model of narcolepsy. Sleep 2013. [PMID: 23449602 DOI: 10.5665/sleep.2442.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
STUDY OBJECTIVES Humans with narcolepsy and orexin/ataxin-3 transgenic (TG) mice exhibit extensive, but incomplete, degeneration of hypo-cretin (Hcrt) neurons. Partial Hcrt cell loss also occurs in Parkinson disease and other neurologic conditions. Whether Hcrt antagonists such as almorexant (ALM) can exert an effect on the Hcrt that remains after Hcrt neurodegeneration has not yet been determined. The current study was designed to evaluate the hypnotic and cataplexy-inducing efficacy of a Hcrt antagonist in an animal model with low Hcrt tone and compare the ALM efficacy profile in the disease model to that produced in wild-type (WT) control animals. DESIGN Counterbalanced crossover study. SETTING Home cage. PATIENTS OR PARTICIPANTS Nine TG mice and 10 WT mice. INTERVENTIONS ALM (30, 100, 300 mg/kg), vehicle and positive control injections, dark/active phase onset. MEASUREMENTS AND RESULTS During the 12-h dark period after dosing, ALM exacerbated cataplexy in TG mice and increased nonrapid eye movement sleep with heightened sleep/wake fragmentation in both genotypes. ALM showed greater hypnotic potency in WT mice than in TG mice. The 100 mg/kg dose conferred maximal promotion of cataplexy in TG mice and maximal promotion of REM sleep in WT mice. In TG mice, ALM (30 mg/ kg) paradoxically induced a transient increase in active wakefulness. Core body temperature (Tb) decreased after acute Hcrt receptor blockade, but the reduction in Tb that normally accompanies the wake-to-sleep transition was blunted in TG mice. CONCLUSIONS These complex dose- and genotype-dependent interactions underscore the importance of effector mechanisms downstream from Hcrt receptors that regulate arousal state. Cataplexy promotion by ALM warrants cautious use of Hcrt antagonists in patient populations with Hcrt neurodegeneration, but may also facilitate the discovery of anticataplectic medications. CITATION Black SW; Morairty SR; Fisher SP; Chen TM; Warrier DR; Kilduff TS. Almorexant promotes sleep and exacerbates cataplexy in a murine model of narcolepsy. SLEEP 2013;36(3):325-336.
Collapse
|
43
|
Gotter AL, Webber AL, Coleman PJ, Renger JJ, Winrow CJ. International Union of Basic and Clinical Pharmacology. LXXXVI. Orexin Receptor Function, Nomenclature and Pharmacology. Pharmacol Rev 2012; 64:389-420. [DOI: 10.1124/pr.111.005546] [Citation(s) in RCA: 133] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
|
44
|
Nishino S, Deguzman C, Yamadera W, Chiba S, Kanbayashi T. Neurochemistry and Biomarkers of Narcolepsy and Other Primary and Secondary Hypersomnias. Sleep Med Clin 2012. [DOI: 10.1016/j.jsmc.2012.03.015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
45
|
Ludvikova E, Nishino S, Sakai N, Jahn P. Familial narcolepsy in the Lipizzaner horse: a report of three fillies born to the same sire. Vet Q 2012; 32:99-102. [PMID: 22889297 DOI: 10.1080/01652176.2012.714089] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
|
46
|
De la Herrán-Arita AK, Drucker-Colín R. Models for narcolepsy with cataplexy drug discovery. Expert Opin Drug Discov 2012; 7:155-64. [DOI: 10.1517/17460441.2012.651454] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
47
|
Shahid IZ, Rahman AA, Pilowsky PM. Orexin and Central Regulation of Cardiorespiratory System. SLEEP HORMONES 2012; 89:159-84. [DOI: 10.1016/b978-0-12-394623-2.00009-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
48
|
Jia X, Yan J, Xia J, Xiong J, Wang T, Chen Y, Qi A, Yang N, Fan S, Ye J, Hu Z. Arousal effects of orexin A on acute alcohol intoxication-induced coma in rats. Neuropharmacology 2011; 62:775-83. [PMID: 21924278 DOI: 10.1016/j.neuropharm.2011.08.047] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2011] [Revised: 08/24/2011] [Accepted: 08/28/2011] [Indexed: 11/25/2022]
Abstract
The key role of the hypothalamic neuropeptides orexins in maintenance and promotion of arousal has been well established in normal mammalian animals, but whether orexins exert arousal effects under pathological condition such as coma was little studied. In this study, a model of unconscious rats induced by acute alcohol intoxication was used to examine the effects of orexins through intracerebroventricular injection. The results revealed that either orexin A or orexin B induced decrease of duration of loss of right reflex in alcohol-induced unconscious rats. In the presence of the selective orexin receptor 1 antagonist SB 334867 and orexin receptor 2 antagonist TCS OX2 29, the excitatory action of orexin A was completely blocked. Our data further presented that orexin A also induced reduction of delta power in EEG in these rats. Single-unit recording experiment in vivo demonstrated that orexin A could evoke increase of firing activity of prefrontal cortex neurons in unconscious rats. This excitation was completely inhibited by an H(1) receptor antagonist, pyrilamine, whereas application of α(1)-adrenoreceptor antagonist prazosin or 5-HT(2) selective receptor antagonist ritanserin partially attenuated the excitatory effects of orexin A on these neurons. Consistently, the results of EEG recordings showed that microinjection of pyrilamine, prazosin, or ritanserin suppressed reduction of delta power in EEG induced by orexin A on unconscious rats. Thus, these data suggest that orexins exert arousal effects on alcohol-induced unconscious rats by the promotion of cortical activity through activation of histaminergic, noradrenergic and serotonergic systems. This article is part of a Special Issue entitled 'Post-Traumatic Stress Disorder'.
Collapse
Affiliation(s)
- Xiaojun Jia
- Department of Physiology, Third Military Medical University, Chongqing 400038, PR China
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
49
|
|
50
|
|