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Bjorness TE, Greene RW. Orexin-mediated Motivated Arousal and Reward Seeking. Peptides 2024:171280. [PMID: 39159833 DOI: 10.1016/j.peptides.2024.171280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2024] [Revised: 08/03/2024] [Accepted: 08/05/2024] [Indexed: 08/21/2024]
Abstract
The neuromodulator orexin has been identified as a key factor for motivated arousal including recent evidence that sleep deprivation-induced enhancement of reward behavior is modulated by orexin. While orexin is not necessary for either reward or arousal behavior, orexin neurons' broad projections, ability to sense the internal state of the animal, and high plasticity of signaling in response to natural rewards and drugs of abuse may underlie heightened drug seeking, particularly in a subset of highly motivated reward seekers. As such, orexin receptor antagonists have gained deserved attention for putative use in addiction treatments. Ongoing and future clinical trials are expected to identify individuals most likely to benefit from orexin receptor antagonist treatment to promote abstinence, such as those with concurrent sleep disorders or high craving, while attention to methodological considerations will aid interpretation of the numerous preclinical studies investigating disparate aspects of the role of orexin in reward and arousal.
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Affiliation(s)
- Theresa E Bjorness
- Research Service, VA North Texas Health Care System, Dallas, TX 75126, USA; Departments of Psychiatry University of Texas Southwestern Medical Center, Dallas, TX 75390-9111, USA.
| | - Robert W Greene
- Departments of Psychiatry University of Texas Southwestern Medical Center, Dallas, TX 75390-9111, USA; Department of Neuroscience, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390-9111, USA; International Institute for Integrative Sleep Medicine, University of Tsukuba, Tsukuba, 305-8577, Japan
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2
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Bohid S, Ali LK, Romero-Leguizamón CR, Langkilde AE, Dos Santos AB, Kohlmeier KA. Sex-dependent effects of monomeric α-synuclein on calcium and cell death of lateral hypothalamic mouse neurons are altered by orexin. Mol Cell Neurosci 2024; 129:103934. [PMID: 38701995 DOI: 10.1016/j.mcn.2024.103934] [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: 09/19/2023] [Revised: 03/25/2024] [Accepted: 04/28/2024] [Indexed: 05/06/2024] Open
Abstract
Parkinson's Disease (PD) patients experience sleeping disorders in addition to the disease-defining symptomology of movement dysfunctions. The prevalence of PD is sex-based and presence of sleeping disorders in PD also shows sex bias with a stronger phenotype in males. In addition to loss of dopamine-containing neurons in the striatum, arousal-related, orexin-containing neurons in the lateral hypothalamus (LH) are lost in PD, which could contribute to state-related disorders. As orexin has been shown to be involved in sleeping disorders and to have neuroprotective effects, we asked whether orexin could protect sleep-related LH neurons from damage putatively from the protein α-synuclein (α-syn), which is found at high levels in the PD brain and that we have shown is associated with putatively excitotoxic rises in intracellular calcium in brainstem sleep-controlling nuclei, especially in males. Accordingly, we monitored intracellular calcium transients induced by α-syn and whether concurrent exposure to orexin affected those transients in LH cells of the mouse brain slice using calcium imaging. Further, we used an assay of cell death to determine whether LH cell viability was influenced when α-syn and orexin were co-applied when compared to exposure to α-syn alone. We found that excitatory calcium events induced by α-syn were reduced in amplitude and frequency when orexin was co-applied, and when data were evaluated by sex, this effect was found to be greater in females. In addition, α-syn exposure was associated with cell death that was higher in males, and interestingly, reduced cell death was noted when orexin was present, which did not show a sex bias. We interpret our findings to indicate that orexin is protective to α-syn-mediated damage to hypothalamic neurons, and the actions of orexin on α-syn-induced cellular effects differ between sexes, which could underlie sex-based differences in sleeping disorders in PD.
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Affiliation(s)
- Sara Bohid
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Lara Kamal Ali
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Cesar Ramon Romero-Leguizamón
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2100 Copenhagen, Denmark.
| | - Annette E Langkilde
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2100 Copenhagen, Denmark.
| | - Altair Brito Dos Santos
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Kristi A Kohlmeier
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2100 Copenhagen, Denmark.
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3
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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.
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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
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Katsuki F, Spratt TJ, Brown RE, Basheer R, Uygun DS. Sleep-Deep-Learner is taught sleep-wake scoring by the end-user to complete each record in their style. SLEEP ADVANCES : A JOURNAL OF THE SLEEP RESEARCH SOCIETY 2024; 5:zpae022. [PMID: 38638581 PMCID: PMC11025629 DOI: 10.1093/sleepadvances/zpae022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Revised: 03/24/2024] [Indexed: 04/20/2024]
Abstract
Sleep-wake scoring is a time-consuming, tedious but essential component of clinical and preclinical sleep research. Sleep scoring is even more laborious and challenging in rodents due to the smaller EEG amplitude differences between states and the rapid state transitions which necessitate scoring in shorter epochs. Although many automated rodent sleep scoring methods exist, they do not perform as well when scoring new datasets, especially those which involve changes in the EEG/EMG profile. Thus, manual scoring by expert scorers remains the gold standard. Here we take a different approach to this problem by using a neural network to accelerate the scoring of expert scorers. Sleep-Deep-Learner creates a bespoke deep convolution neural network model for individual electroencephalographic or local-field-potential (LFP) records via transfer learning of GoogLeNet, by learning from a small subset of manual scores of each EEG/LFP record as provided by the end-user. Sleep-Deep-Learner then automates scoring of the remainder of the EEG/LFP record. A novel REM sleep scoring correction procedure further enhanced accuracy. Sleep-Deep-Learner reliably scores EEG and LFP data and retains sleep-wake architecture in wild-type mice, in sleep induced by the hypnotic zolpidem, in a mouse model of Alzheimer's disease and in a genetic knock-down study, when compared to manual scoring. Sleep-Deep-Learner reduced manual scoring time to 1/12. Since Sleep-Deep-Learner uses transfer learning on each independent recording, it is not biased by previously scored existing datasets. Thus, we find Sleep-Deep-Learner performs well when used on signals altered by a drug, disease model, or genetic modification.
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Affiliation(s)
- Fumi Katsuki
- Department of Psychiatry, VA Boston Healthcare System and Harvard Medical School, West Roxbury, MA, USA
| | - Tristan J Spratt
- Department of Psychiatry, VA Boston Healthcare System and Harvard Medical School, West Roxbury, MA, USA
| | - Ritchie E Brown
- Department of Psychiatry, VA Boston Healthcare System and Harvard Medical School, West Roxbury, MA, USA
| | - Radhika Basheer
- Department of Psychiatry, VA Boston Healthcare System and Harvard Medical School, West Roxbury, MA, USA
| | - David S Uygun
- Department of Psychiatry, VA Boston Healthcare System and Harvard Medical School, West Roxbury, MA, USA
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Giatti S, Cioffi L, Diviccaro S, Piazza R, Melcangi RC. Analysis of the finasteride treatment and its withdrawal in the rat hypothalamus and hippocampus at whole-transcriptome level. J Endocrinol Invest 2024:10.1007/s40618-024-02345-y. [PMID: 38493246 DOI: 10.1007/s40618-024-02345-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Accepted: 02/18/2024] [Indexed: 03/18/2024]
Abstract
PURPOSE As reported in patients treated for androgenetic alopecia with finasteride (i.e., a blocker of the enzyme 5 alpha-reductase) and in an animal model, side effects affecting sexual, psychiatric, neurological, and physical domains, may occur during the treatment and persist with drug suspension. The etiopathogenesis of these side effects has been poorly explored. Therefore, we performed a genome-wide analysis of finasteride effects in the brain of adult male rat. METHODS Animals were treated (i.e., for 20 days) with finasteride (1mg/rat/day). 24 h after the last treatment and 1 month after drug suspension, RNA sequencing analysis was performed in hypothalamus and hippocampus. Data were analyzed by differential expression analysis and Gene-Set Enrichment Analyses (GSEA). RESULTS Data obtained after finasteride treatment showed that 186 genes (i.e., 171 up- and 15 downregulated) and 19 (i.e., 17 up- and 2 downregulated) were differentially expressed in the hypothalamus and hippocampus, respectively. Differential expression analysis at the drug withdrawal failed to identify dysregulated genes. Several gene-sets were enriched in these brain areas at both time points. CONCLUSION Some of the genes reported to be differentially expressed (i.e., TTR, DIO2, CLDN1, CLDN2, SLC4A5, KCNE2, CROT, HCRT, MARCKSL1, VGF, IRF2BPL) and GSEA, suggest a potential link with specific side effects previously observed in patients and in the animal model, such as depression, anxiety, disturbance in memory and attention, and sleep disturbance. These data may provide an important background for future experiments aimed at confirming the pathological role of these genes.
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Affiliation(s)
- S Giatti
- Dipartimento di Scienze Farmacologiche e Biomolecolari "Rodolfo Paoletti", Università degli Studi di Milano, Via Balzaretti 9, 20133, Milan, Italy
| | - L Cioffi
- Dipartimento di Scienze Farmacologiche e Biomolecolari "Rodolfo Paoletti", Università degli Studi di Milano, Via Balzaretti 9, 20133, Milan, Italy
| | - S Diviccaro
- Dipartimento di Scienze Farmacologiche e Biomolecolari "Rodolfo Paoletti", Università degli Studi di Milano, Via Balzaretti 9, 20133, Milan, Italy
| | - R Piazza
- Dipartimento di Medicina e Chirurgia, Università di Milano-Bicocca, Milan, Italy
| | - R C Melcangi
- Dipartimento di Scienze Farmacologiche e Biomolecolari "Rodolfo Paoletti", Università degli Studi di Milano, Via Balzaretti 9, 20133, Milan, Italy.
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Braun A, Manavis J, Yamanaka A, Ootsuka Y, Blumbergs P, Bobrovskaya L. The role of orexin in Parkinson's disease. J Neurosci Res 2024; 102:e25322. [PMID: 38520160 DOI: 10.1002/jnr.25322] [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] [Received: 09/01/2023] [Revised: 02/28/2024] [Accepted: 03/09/2024] [Indexed: 03/25/2024]
Abstract
Emerging evidence has implicated the orexin system in non-motor pathogenesis of Parkinson's disease. It has also been suggested the orexin system is involved in the modulation of motor control, further implicating the orexin system in Parkinson's disease. Parkinson's disease is the second most common neurodegenerative disease with millions of people suffering worldwide with motor and non-motor symptoms, significantly affecting their quality of life. Treatments are based solely on symptomatic management and no cure currently exists. The orexin system has the potential to be a treatment target in Parkinson's disease, particularly in the non-motor stage. In this review, the most current evidence on the orexin system in Parkinson's disease and its potential role in motor and non-motor symptoms of the disease is summarized. This review begins with a brief overview of Parkinson's disease, animal models of the disease, and the orexin system. This leads into discussion of the possible roles of orexin neurons in Parkinson's disease and levels of orexin in the cerebral spinal fluid and plasma in Parkinson's disease and animal models of the disease. The role of orexin is then discussed in relation to symptoms of the disease including motor control, sleep, cognitive impairment, psychological behaviors, and the gastrointestinal system. The neuroprotective effects of orexin are also summarized in preclinical models of the disease.
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Affiliation(s)
- Alisha Braun
- Health and Biomedical Innovation, Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Jim Manavis
- Discipline of Anatomy and Pathology, Adelaide Medical School, University of Adelaide, Adelaide, South Australia, Australia
| | | | - Youichirou Ootsuka
- College of Medicine and Public Health, Flinders Medical and Health Research Institute, Flinders University, Adelaide, South Australia, Australia
| | - Peter Blumbergs
- Discipline of Anatomy and Pathology, Adelaide Medical School, University of Adelaide, Adelaide, South Australia, Australia
| | - Larisa Bobrovskaya
- Health and Biomedical Innovation, Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
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Wang W, Ranjan A, Zhang W, Liang Q, MacMillan KS, Chapman K, Wang X, Chandrasekaran P, Williams NS, Rosenbaum DM, De Brabander JK. Novel orexin receptor agonists based on arene- or pyridine-fused 1,3-dihydro-2H-imidazole-2-imines. Bioorg Med Chem Lett 2024; 99:129624. [PMID: 38272190 DOI: 10.1016/j.bmcl.2024.129624] [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: 10/25/2023] [Revised: 12/15/2023] [Accepted: 01/18/2024] [Indexed: 01/27/2024]
Abstract
A structurally novel class of benzo- or pyrido-fused 1,3-dihydro-2H-imidazole-2-imines was designed and evaluated in an inositol phosphate accumulation assay for Gq signaling to measure agonistic activation of the orexin receptor type 2 (OX2R). These compounds were synthesized in 4-9 steps overall from readily available starting materials. Analogs that contain a stereogenic methyl or cyclopropyl substituent at the benzylic center, and a correctly configured alkyl ether, alkoxyalkyl ether, cyanoalkyl ether, or α-hydroxyacetamido substituted homobenzylic sidechain were identified as the most potent activators of OX2R coupled Gq signaling. Our results also indicate that agonistic activity was stereospecific at both the benzylic and homobenzylic stereogenic centra. We identified methoxyethoxy-substituted pyrido-fused dihydroimidazolimine analog 63c containing a stereogenic benzylic methyl group was the most potent agonist, registering a respectable EC50 of 339 nM and a maximal response (Emax) of 96 % in this assay. In vivo pharmacokinetic analysis indicated good brain exposure for several analogs. Our combined results provide important information towards a structurally novel class of orexin receptor agonists distinct from current chemotypes.
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Affiliation(s)
- Wentian Wang
- Department of Biochemistry, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-9038, USA
| | - Alok Ranjan
- Department of Biochemistry, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-9038, USA
| | - Wei Zhang
- Department of Biochemistry, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-9038, USA
| | - Qiren Liang
- Department of Biochemistry, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-9038, USA
| | - Karen S MacMillan
- Department of Biochemistry, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-9038, USA
| | - Karen Chapman
- Department of Biophysics, University of Texas Southwestern Medical Center, 6001 Forest Park Rd., Dallas, TX 75390-9041, USA
| | - Xiaoyu Wang
- Department of Biochemistry, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-9038, USA
| | - Preethi Chandrasekaran
- Department of Biophysics, University of Texas Southwestern Medical Center, 6001 Forest Park Rd., Dallas, TX 75390-9041, USA
| | - Noelle S Williams
- Department of Biochemistry, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-9038, USA
| | - Daniel M Rosenbaum
- Department of Biophysics, University of Texas Southwestern Medical Center, 6001 Forest Park Rd., Dallas, TX 75390-9041, USA.
| | - Jef K De Brabander
- Department of Biochemistry, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-9038, USA.
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8
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Dong P, Dai W, Su M, Wang S, Ma Y, Zhao T, Zheng F, Sun P. The potential role of the orexin system in premenstrual syndrome. Front Endocrinol (Lausanne) 2024; 14:1266806. [PMID: 38292774 PMCID: PMC10824941 DOI: 10.3389/fendo.2023.1266806] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 12/29/2023] [Indexed: 02/01/2024] Open
Abstract
Premenstrual syndrome (PMS) occurs recurrently during the luteal phase of a woman's menstrual cycle and disappears after menstruation ends. It is characterized by abnormal changes in both the body and mood, and in certain cases, severe disruptions in daily life and even suicidal tendencies. Current drugs for treating PMS, such as selective serotonin reuptake inhibitors, do not yield satisfactory results. Orexin, a neuropeptide produced in the lateral hypothalamus, is garnering attention in the treatment of neurological disorders and is believed to modulate the symptoms of PMS. This paper reviews the advancements in research on sleep disturbances, mood changes, and cognitive impairment caused by PMS, and suggests potential pathways for orexin to address these symptoms. Furthermore, it delves into the role of orexin in the molecular mechanisms underlying PMS. Orexin regulates steroid hormones, and the cyclic fluctuations of estrogen and progesterone play a crucial role in the pathogenesis of PMS. Additionally, orexin also modulates the gamma-aminobutyric acid (GABA) system and the inflammatory response involved in coordinating the mechanism of PMS. Unraveling the role of orexin in the pathogenesis of PMS will not only aid in understanding the etiology of PMS but also hold implications for orexin as a novel target for treating PMS.
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Affiliation(s)
- Ping Dong
- School of Traditional Chinese Medicine, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Weibo Dai
- Department of Pharmacy, Zhongshan Hospital of Traditional Chinese Medicine, Zhong Shan, China
| | - Mengyue Su
- School of Pharmacy, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Shukun Wang
- School of Pharmacy, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Yuexiang Ma
- School of Traditional Chinese Medicine, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Tingting Zhao
- College of Foreign Languages, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Feng Zheng
- Department of Neurosurgery, The Second Affiliated Hospital of Fujian Medical University, Quanzhou, China
| | - Peng Sun
- Innovation Research Institute of Chinese Medicine, Shandong University of Traditional Chinese Medicine, Jinan, China
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9
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Katsuki F, Spratt TJ, Brown RE, Basheer R, Uygun DS. Sleep-Deep-Net learns sleep wake scoring from the end-user and completes each record in their style. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.22.573151. [PMID: 38187568 PMCID: PMC10769368 DOI: 10.1101/2023.12.22.573151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
Sleep-wake scoring is a time-consuming, tedious but essential component of clinical and pre-clinical sleep research. Sleep scoring is even more laborious and challenging in rodents due to the smaller EEG amplitude differences between states and the rapid state transitions which necessitate scoring in shorter epochs. Although many automated rodent sleep scoring methods exist, they do not perform as well when scoring new data sets, especially those which involve changes in the EEG/EMG profile. Thus, manual scoring by expert scorers remains the gold-standard. Here we take a different approach to this problem by using a neural network to accelerate the scoring of expert scorers. Sleep-Deep-Net (SDN) creates a bespoke deep convolution neural network model for individual electroencephalographic or local-field-potential records via transfer learning of GoogleNet, by learning from a small subset of manual scores of each EEG/LFP record as provided by the end-user. SDN then automates scoring of the remainder of the EEG/LFP record. A novel REM scoring correction procedure further enhanced accuracy. SDN reliably scores EEG and LFP data and retains sleep-wake architecture in wild-type mice, in sleep induced by the hypnotic zolpidem, in a mouse model of Alzheimer's disease and in a genetic knock-down study, when compared to manual scoring. SDN reduced manual scoring time to 1/12. Since SDN uses transfer learning on each independent recording, it is not biased by previously scored existing data sets. Thus, we find SDN performs well when used on signals altered by a drug, disease model or genetic modification.
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Affiliation(s)
- Fumi Katsuki
- VA Boston Healthcare System and Harvard Medical School, Dept. of Psychiatry, West Roxbury, MA 02132, USA
| | - Tristan J Spratt
- VA Boston Healthcare System and Harvard Medical School, Dept. of Psychiatry, West Roxbury, MA 02132, USA
| | - Ritchie E Brown
- VA Boston Healthcare System and Harvard Medical School, Dept. of Psychiatry, West Roxbury, MA 02132, USA
| | - Radhika Basheer
- VA Boston Healthcare System and Harvard Medical School, Dept. of Psychiatry, West Roxbury, MA 02132, USA
| | - David S Uygun
- VA Boston Healthcare System and Harvard Medical School, Dept. of Psychiatry, West Roxbury, MA 02132, USA
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Ito H, Fukatsu N, Rahaman SM, Mukai Y, Izawa S, Ono D, Kilduff TS, Yamanaka A. Deficiency of orexin signaling during sleep is involved in abnormal REM sleep architecture in narcolepsy. Proc Natl Acad Sci U S A 2023; 120:e2301951120. [PMID: 37796986 PMCID: PMC10576136 DOI: 10.1073/pnas.2301951120] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Accepted: 07/10/2023] [Indexed: 10/07/2023] Open
Abstract
Narcolepsy is a sleep disorder caused by deficiency of orexin signaling. However, the neural mechanisms by which deficient orexin signaling causes the abnormal rapid eye movement (REM) sleep characteristics of narcolepsy, such as cataplexy and frequent transitions to REM states, are not fully understood. Here, we determined the activity dynamics of orexin neurons during sleep that suppress the abnormal REM sleep architecture of narcolepsy. Orexin neurons were highly active during wakefulness, showed intermittent synchronous activity during non-REM (NREM) sleep, were quiescent prior to the transition from NREM to REM sleep, and a small subpopulation of these cells was active during REM sleep. Orexin neurons that lacked orexin peptides were less active during REM sleep and were mostly silent during cataplexy. Optogenetic inhibition of orexin neurons established that the activity dynamics of these cells during NREM sleep regulate NREM-REM sleep transitions. Inhibition of orexin neurons during REM sleep increased subsequent REM sleep in "orexin intact" mice and subsequent cataplexy in mice lacking orexin peptides, indicating that the activity of a subpopulation of orexin neurons during the preceding REM sleep suppresses subsequent REM sleep and cataplexy. Thus, these results identify how deficient orexin signaling during sleep results in the abnormal REM sleep architecture characteristic of narcolepsy.
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Affiliation(s)
- Hiroto Ito
- Department of Neuroscience II, Research Institute of Environmental Medicine, Nagoya University, Nagoya464-8601, Japan
- Department of Neural Regulation, Nagoya University Graduate School of Medicine, Nagoya466-8550, Japan
- Japan Society for the Promotion of Science Research Fellowship for Young Scientists, Tokyo102-0083, Japan
| | - Noriaki Fukatsu
- Department of Neuroscience II, Research Institute of Environmental Medicine, Nagoya University, Nagoya464-8601, Japan
- Department of Neural Regulation, Nagoya University Graduate School of Medicine, Nagoya466-8550, Japan
| | - Sheikh Mizanur Rahaman
- Department of Neuroscience II, Research Institute of Environmental Medicine, Nagoya University, Nagoya464-8601, Japan
- Department of Neural Regulation, Nagoya University Graduate School of Medicine, Nagoya466-8550, Japan
| | - Yasutaka Mukai
- Department of Neuroscience II, Research Institute of Environmental Medicine, Nagoya University, Nagoya464-8601, Japan
- Department of Neural Regulation, Nagoya University Graduate School of Medicine, Nagoya466-8550, Japan
| | - Shuntaro Izawa
- Department of Neuroscience II, Research Institute of Environmental Medicine, Nagoya University, Nagoya464-8601, Japan
- Department of Neural Regulation, Nagoya University Graduate School of Medicine, Nagoya466-8550, Japan
| | - Daisuke Ono
- Department of Neuroscience II, Research Institute of Environmental Medicine, Nagoya University, Nagoya464-8601, Japan
- Department of Neural Regulation, Nagoya University Graduate School of Medicine, Nagoya466-8550, Japan
| | - Thomas S. Kilduff
- Center for Neuroscience, Biosciences Division, SRI International, Menlo Park, CA94025
| | - Akihiro Yamanaka
- Department of Neuroscience II, Research Institute of Environmental Medicine, Nagoya University, Nagoya464-8601, Japan
- Department of Neural Regulation, Nagoya University Graduate School of Medicine, Nagoya466-8550, Japan
- Chinese Institute for Brain Research, Beijing102206, China
- National Institute for Physiological Sciences, Aichi444-8585, Japan
- National Institutes of Natural Sciences, Aichi444-8585, Japan
- Division of Brain Sciences Institute for Advanced Medical Research, Keio University School of Medicine, Tokyo160-8582, Japan
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11
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Mignot E, Bogan RK, Emsellem H, Foldvary-Schaefer N, Naylor M, Neuwirth R, Faessel H, Swick T, Olsson T. Safety and pharmacodynamics of a single infusion of danavorexton in adults with idiopathic hypersomnia. Sleep 2023; 46:zsad049. [PMID: 36883238 PMCID: PMC10485568 DOI: 10.1093/sleep/zsad049] [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] [Received: 11/30/2022] [Revised: 02/09/2023] [Indexed: 03/09/2023] Open
Abstract
STUDY OBJECTIVES Idiopathic hypersomnia (IH) is a chronic disorder characterized by excessive daytime sleepiness unexplained by another disorder or drug/medication use. Although the orexin system plays a role in sleep-wake regulation, orexin A levels in the cerebrospinal fluid are normal in people with IH. This phase 1b, randomized, placebo-controlled, crossover study aimed to investigate the safety, pharmacokinetics, and pharmacodynamics of danavorexton, a small-molecule orexin-2 receptor agonist, in adults with IH. METHODS Adults with IH aged 18-75 years were randomized to one of two treatment sequences of single intravenous infusions of danavorexton 112 mg and placebo. Pharmacodynamic endpoints included the maintenance of wakefulness test (MWT), the Karolinska Sleepiness Scale (KSS), and the psychomotor vigilance task (PVT). Adverse events were monitored throughout the study period. RESULTS Of 28 randomized participants, 12 (44.4%) had a treatment-emergent adverse event (TEAE) and 10 (37.0%) had a TEAE considered related to study drug, most of which were mild or moderate. Four participants (18.2%) had urinary TEAEs while receiving danavorexton, all of which were mild in severity. There were no deaths or TEAEs leading to discontinuation. Improvements in MWT, KSS, and PVT scores were observed with danavorexton compared to placebo. Following drug administration, a mean sleep latency of 40 min (maximum value) was observed during the MWT within 2 h of danavorexton infusion in most participants. CONCLUSIONS A single infusion of danavorexton improves subjective and objective excessive daytime sleepiness in people with IH with no serious TEAEs, indicating orexin-2 receptor agonists are promising treatments for IH. Clinical Trial: Clinicaltrials.gov. https://clinicaltrials.gov/ct2/show/NCT04091438.
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Affiliation(s)
- Emmanuel Mignot
- Stanford Department of Psychiatry and Behavioral Medicine, Center for Sleep Sciences and Medicine, Stanford University Medical School, Palo Alto, CA, USA
| | | | | | | | - Melissa Naylor
- Takeda Development Center Americas, Inc., Lexington, MA, USA
| | - Rachel Neuwirth
- Takeda Development Center Americas, Inc., Lexington, MA, USA
| | - Hélène Faessel
- Takeda Development Center Americas, Inc., Lexington, MA, USA
| | - Todd Swick
- Takeda Development Center Americas, Inc., Lexington, MA, USA
| | - Tina Olsson
- Takeda Development Center Americas, Inc., Lexington, MA, USA
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12
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Sun Y, Ranjan A, Tisdale R, Ma SC, Park S, Haire M, Heu J, Morairty SR, Wang X, Rosenbaum DM, Williams NS, Brabander JKD, Kilduff TS. Evaluation of the efficacy of the hypocretin/orexin receptor agonists TAK-925 and ARN-776 in narcoleptic orexin/tTA; TetO-DTA mice. J Sleep Res 2023; 32:e13839. [PMID: 36808670 PMCID: PMC10356740 DOI: 10.1111/jsr.13839] [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] [Received: 09/13/2022] [Revised: 11/29/2022] [Accepted: 01/16/2023] [Indexed: 02/22/2023]
Abstract
The sleep disorder narcolepsy, a hypocretin deficiency disorder thought to be due to degeneration of hypothalamic hypocretin/orexin neurons, is currently treated symptomatically. We evaluated the efficacy of two small molecule hypocretin/orexin receptor-2 (HCRTR2) agonists in narcoleptic male orexin/tTA; TetO-DTA mice. TAK-925 (1-10 mg/kg, s.c.) and ARN-776 (1-10 mg/kg, i.p.) were injected 15 min before dark onset in a repeated measures design. EEG, EMG, subcutaneous temperature (Tsc ) and activity were recorded by telemetry; recordings for the first 6 h of the dark period were scored for sleep/wake and cataplexy. At all doses tested, TAK-925 and ARN-776 caused continuous wakefulness and eliminated sleep for the first hour. Both TAK-925 and ARN-776 caused dose-related delays in NREM sleep onset. All doses of TAK-925 and all but the lowest dose of ARN-776 eliminated cataplexy during the first hour after treatment; the anti-cataplectic effect of TAK-925 persisted into the second hour for the highest dose. TAK-925 and ARN-776 also reduced the cumulative amount of cataplexy during the 6 h post-dosing period. The acute increase in wakefulness produced by both HCRTR2 agonists was characterised by increased spectral power in the gamma EEG band. Although neither compound provoked a NREM sleep rebound, both compounds affected NREM EEG during the second hour post-dosing. TAK-925 and ARN-776 also increased gross motor activity, running wheel activity, and Tsc , suggesting that the wake-promoting and sleep-suppressing activities of these compounds could be a consequence of hyperactivity. Nonetheless, the anti-cataplectic activity of TAK-925 and ARN-776 is encouraging for the development of HCRTR2 agonists.
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Affiliation(s)
- Yu Sun
- Biosciences Division, SRI International, 333 Ravenswood Ave, Menlo Park, CA 94025, USA
| | - Alok Ranjan
- Department of Biochemistry, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Ryan Tisdale
- Biosciences Division, SRI International, 333 Ravenswood Ave, Menlo Park, CA 94025, USA
| | - Shun-Chieh Ma
- Biosciences Division, SRI International, 333 Ravenswood Ave, Menlo Park, CA 94025, USA
| | - Sunmee Park
- Biosciences Division, SRI International, 333 Ravenswood Ave, Menlo Park, CA 94025, USA
| | - Meghan Haire
- Biosciences Division, SRI International, 333 Ravenswood Ave, Menlo Park, CA 94025, USA
| | - Jasmine Heu
- Biosciences Division, SRI International, 333 Ravenswood Ave, Menlo Park, CA 94025, USA
| | - Stephen R. Morairty
- Biosciences Division, SRI International, 333 Ravenswood Ave, Menlo Park, CA 94025, USA
| | - Xiaoyu Wang
- Department of Biochemistry, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Daniel M. Rosenbaum
- Department of Biochemistry, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
- Department of Biophysics, The University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Noelle S. Williams
- Department of Biochemistry, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Jef K. De Brabander
- Department of Biochemistry, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Thomas S. Kilduff
- Biosciences Division, SRI International, 333 Ravenswood Ave, Menlo Park, CA 94025, USA
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13
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Abad VC. Pharmacological options for narcolepsy: are they the way forward? Expert Rev Neurother 2023; 23:819-834. [PMID: 37585269 DOI: 10.1080/14737175.2023.2249234] [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: 07/16/2023] [Revised: 08/13/2023] [Accepted: 08/14/2023] [Indexed: 08/18/2023]
Abstract
INTRODUCTION Narcolepsy is an under-recognized, rare neurologic disorder of hypersomnolence that is associated with increased mortality and medical and psychiatric co-morbidities. Narcolepsy exerts a substantial economic burden on patients and society. There is currently no cure, and life-long symptomatic therapy is needed. Available drugs do not modify the disease course. AREAS COVERED This manuscript provides an overview of narcolepsy symptoms, diagnosis, pathophysiology, current pharmacotherapies, and emerging treatments. Gaps and unresolved issues in diagnosis and management of narcolepsy are discussed to answer whether pharmacological options are the way forward. EXPERT OPINION Diagnostic criteria for narcolepsy (ICSD-3) need revision and greater clarity. Improved recognition of cataplexy and other symptoms through educational outreach, new biomarkers, improved test scoring through artificial intelligence algorithms, and use of machine learning may facilitate earlier diagnosis and treatment. Pharmacological options need improved symptomatic therapy in addition to targeted therapies that address the loss of hypocretin signaling. Optimal narcolepsy care also needs a better understanding of the pathophysiology, recognition of the different phenotypes in narcolepsy, identification of at-risk individuals and early recognition of symptoms, better diagnostic tools, and a database for research and disease monitoring of treatment, side-effects, and comorbidities.
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Affiliation(s)
- Vivien C Abad
- Division of Sleep Medicine, Department of Psychiatry and Behavioral Sciences Stanford University, Redwood, CA, USA
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14
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Pintwala SK, Fraigne JJ, Belsham DD, Peever JH. Immortal orexin cell transplants restore motor-arousal synchrony during cataplexy. Curr Biol 2023; 33:1550-1564.e5. [PMID: 37044089 DOI: 10.1016/j.cub.2023.03.077] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 03/11/2023] [Accepted: 03/27/2023] [Indexed: 04/14/2023]
Abstract
Waking behaviors such as sitting or standing require suitable levels of muscle tone. But it is unclear how arousal and motor circuits communicate with one another so that appropriate motor tone occurs during wakefulness. Cataplexy is a peculiar condition in which muscle tone is involuntarily lost during normal periods of wakefulness. Cataplexy therefore provides a unique opportunity for identifying the signaling mechanisms that synchronize motor and arousal behaviors. Cataplexy occurs when hypothalamic orexin neurons are lost in narcolepsy; however, it is unclear if motor-arousal decoupling in cataplexy is directly or indirectly caused by orexin cell loss. Here, we used genomic, proteomic, chemogenetic, electrophysiological, and behavioral assays to determine if grafting orexin cells into the brain of cataplectic (i.e., orexin-/-) mice restores normal motor-arousal behaviors by preventing cataplexy. First, we engineered immortalized orexin cells and found that they not only produce and release orexin but also exhibit a gene profile that mimics native orexin neurons. Second, we show that engineered orexin cells thrive and integrate into host tissue when transplanted into the brain of mice. Next, we found that grafting only 200-300 orexin cells into the dorsal raphe nucleus-a region densely innervated by native orexin neurons-reduces cataplexy. Last, we show that real-time chemogenetic activation of orexin cells restores motor-arousal synchrony by preventing cataplexy. We suggest that orexin signaling is critical for arousal-motor synchrony during wakefulness and that the dorsal raphe plays a pivotal role in coupling arousal and motor behaviors.
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Affiliation(s)
- Sara K Pintwala
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada
| | - Jimmy J Fraigne
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada
| | - Denise D Belsham
- Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada; Department of Obstetrics and Gynecology, University of Toronto, Toronto, ON M5S 1A8, Canada; Department of Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - John H Peever
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada; Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada.
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15
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Ten-Blanco M, Flores Á, Cristino L, Pereda-Pérez I, Berrendero F. Targeting the orexin/hypocretin system for the treatment of neuropsychiatric and neurodegenerative diseases: from animal to clinical studies. Front Neuroendocrinol 2023; 69:101066. [PMID: 37015302 DOI: 10.1016/j.yfrne.2023.101066] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Revised: 03/15/2023] [Accepted: 03/30/2023] [Indexed: 04/06/2023]
Abstract
Orexins (also known as hypocretins) are neuropeptides located exclusively in hypothalamic neurons that have extensive projections throughout the central nervous system and bind two different G protein-coupled receptors (OX1R and OX2R). Since its discovery in 1998, the orexin system has gained the interest of the scientific community as a potential therapeutic target for the treatment of different pathological conditions. Considering previous basic science research, a dual orexin receptor antagonist, suvorexant, was the first orexin agent to be approved by the US Food and Drug Administration to treat insomnia. In this review, we discuss and update the main preclinical and human studies involving the orexin system with several psychiatric and neurodegenerative diseases. This system constitutes a nice example of how basic scientific research driven by curiosity can be the best route to the generation of new and powerful pharmacological treatments.
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Affiliation(s)
- Marc Ten-Blanco
- Faculty of Experimental Sciences, Universidad Francisco de Vitoria, 28223 Pozuelo de Alarcón, Madrid, Spain
| | - África Flores
- Pharmacology Unit, Department of Pathology and Experimental Therapeutics, Neurosciences Institute, University of Barcelona and Bellvitge University Hospital-IDIBELL, 08908 L'Hospitalet de Llobregat, Barcelona, Spain
| | - Luigia Cristino
- Endocannabinoid Research Group, Institute of Biomolecular Chemistry (ICB), National Research Council (CNR), Pozzuoli, Italy
| | - Inmaculada Pereda-Pérez
- Faculty of Experimental Sciences, Universidad Francisco de Vitoria, 28223 Pozuelo de Alarcón, Madrid, Spain
| | - Fernando Berrendero
- Faculty of Experimental Sciences, Universidad Francisco de Vitoria, 28223 Pozuelo de Alarcón, Madrid, Spain.
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16
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Sheibani M, Shayan M, Khalilzadeh M, Ghasemi M, Dehpour AR. Orexin receptor antagonists in the pathophysiology and treatment of sleep disorders and epilepsy. Neuropeptides 2023; 99:102335. [PMID: 37003137 DOI: 10.1016/j.npep.2023.102335] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2023] [Revised: 03/20/2023] [Accepted: 03/23/2023] [Indexed: 03/29/2023]
Abstract
The correlation between sleep and epilepsy has been argued over the past decades among scientists. Although the similarities and contrasts between sleep and epilepsy had been considered, their intertwined nature was not revealed until the nineteenth century. Sleep is recognized as a recurring state of mind and body through alternating brain electrical activities. It is documented that sleep disorders are associated with epilepsy. The origin, suppression, and spread of seizures are affected by sleep. As such, in patients with epilepsy, sleep disorders are a frequent comorbidity. Meanwhile, orexin, a wake-promoting neuropeptide, provides a bidirectional effect on both sleep and epilepsy. Orexin and its cognate receptors, orexin receptor type 1 (OX1R) and type 2 (OX2R), orchestrate their effects by activating various downstream signaling pathways. Although orexin was considered a therapeutic target in insomnia shortly after its discovery, its potential usefulness for psychiatric disorders and epileptic seizures has been suggested in the pre-clinical studies. This review aimed to discuss whether the relationship between sleep, epilepsy, and orexin is clearly reciprocal.
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Affiliation(s)
- Mohammad Sheibani
- Department of Pharmacology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran; Razi Drug Research Center, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Maryam Shayan
- Experimental Medicine Research Centre, Tehran University of Medical Sciences, Tehran, Iran; Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Mina Khalilzadeh
- Experimental Medicine Research Centre, Tehran University of Medical Sciences, Tehran, Iran; Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Mehdi Ghasemi
- Department of Neurology, University of Massachusetts Chan Medical School, Worcester, MA 01655, USA.
| | - Ahmad Reza Dehpour
- Experimental Medicine Research Centre, Tehran University of Medical Sciences, Tehran, Iran; Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
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17
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Kawashima S, Lou F, Kusumoto-Yoshida I, Hao L, Kuwaki T. Activation of the rostral nucleus accumbens shell by optogenetics induces cataplexy-like behavior in orexin neuron-ablated mice. Sci Rep 2023; 13:2546. [PMID: 36781929 PMCID: PMC9925750 DOI: 10.1038/s41598-023-29488-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 02/06/2023] [Indexed: 02/15/2023] Open
Abstract
Cataplexy is one of the symptoms of type 1 narcolepsy, characterized by a sudden loss of muscle tone. It can be seen as a behavioral index of salience, predominantly positive emotion, since it is triggered by laughter in humans and palatable foods in mice. In our previous study using chemogenetic techniques in narcoleptic mice (orexin neuron-ablated mice), we found that the rostral nucleus accumbens (NAc) shell is needed for chocolate-induced cataplexy. In this study, we investigated whether a short-lasting stimulation/inhibition of the NAc by optogenetics led to a similar result. Photo-illumination to the NAc in the channel rhodopsin-expressing mice showed a higher incidence (34.9 ± 5.1%) of cataplexy-like behavior than the control mice (17.8 ± 3.1%, P = 0.0056). Meanwhile, inactivation with archaerhodopsin did not affect incidence. The episode duration of cataplexy-like behavior was not affected by activation or inactivation. Immunohistochemical analysis revealed that photo-illumination activated channel rhodopsin-expressing NAc shell neurons. Thus, activation of the NAc, whether transient (light stimulation) or longer-lasting (chemical stimulation in our previous study), facilitates cataplexy-like behaviors and contributes to the induction but not maintenance in them. On the other hand, our study's result from optogenetic inhibition of the NAc (no effect) was different from chemogenetic inhibition (reduction of cataplexy-like behavior) in our previous study. We propose that the initiation of cataplexy-like behavior is facilitated by activation of the NAc, while NAc-independent mechanisms determine the termination of the behavior.
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Affiliation(s)
- Shigetaka Kawashima
- Department of Physiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Fan Lou
- Department of Physiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
- Department of Pharmaceutical Toxicology, School of Pharmacy, China Medical University, Shenyang, China
- The First Affiliated Hospital of China Medical University, Shenyang, China
| | - Ikue Kusumoto-Yoshida
- Department of Physiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Liying Hao
- Department of Pharmaceutical Toxicology, School of Pharmacy, China Medical University, Shenyang, China
| | - Tomoyuki Kuwaki
- Department of Physiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan.
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18
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Guo R, Vaughan DT, Rojo ALA, Huang YH. Sleep-mediated regulation of reward circuits: implications in substance use disorders. Neuropsychopharmacology 2023; 48:61-78. [PMID: 35710601 PMCID: PMC9700806 DOI: 10.1038/s41386-022-01356-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 05/22/2022] [Accepted: 05/27/2022] [Indexed: 12/11/2022]
Abstract
Our modern society suffers from both pervasive sleep loss and substance abuse-what may be the indications for sleep on substance use disorders (SUDs), and could sleep contribute to the individual variations in SUDs? Decades of research in sleep as well as in motivated behaviors have laid the foundation for us to begin to answer these questions. This review is intended to critically summarize the circuit, cellular, and molecular mechanisms by which sleep influences reward function, and to reveal critical challenges for future studies. The review also suggests that improving sleep quality may serve as complementary therapeutics for treating SUDs, and that formulating sleep metrics may be useful for predicting individual susceptibility to SUDs and other reward-associated psychiatric diseases.
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Affiliation(s)
- Rong Guo
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, 15219, USA
- Allen Institute, Seattle, WA, 98109, USA
| | - Dylan Thomas Vaughan
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, 15219, USA
- The Center for Neuroscience at the University of Pittsburgh, Pittsburgh, PA, USA
| | - Ana Lourdes Almeida Rojo
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, 15219, USA
- The Center for Neuroscience at the University of Pittsburgh, Pittsburgh, PA, USA
| | - Yanhua H Huang
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, 15219, USA.
- The Center for Neuroscience at the University of Pittsburgh, Pittsburgh, PA, USA.
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19
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Yoshida M, Yamamoto K, Kuwaki T. Positive memory increases cataplexy-like behaviors in narcolepsy mice as revealed using conditioned place preference test. BMC Neurosci 2022; 23:82. [PMID: 36577939 PMCID: PMC9798626 DOI: 10.1186/s12868-022-00772-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 12/20/2022] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND Cataplexy is a loss of muscle tone that can lead to postural collapse, disturbing the daily life of narcolepsy patients; it is often triggered by positive emotions such as laughter in human patients. Narcolepsy model mice also show cataplexy, and its incidence increases in response to positive emotion-inducing stimuli such as chocolate and female courtship. Although such observation indicates a positive emotion-related nature of cataplexy in narcolepsy mice, they also show cataplexy without any apparent triggering stimulus ~ (spontaneous cataplexy). Therefore, we hypothesized that some spontaneous cataplexy in narcoleptic mice might indicate the remembering of happy moments. RESULTS To test our hypothesis, we did a conditioned place preference test on orexin/hypocretin neuron-ablated (ORX-AB) mice, one of the animal models of human narcolepsy, and counted the number of cataplexy-like behaviors. ORX-AB mice successfully remembered the chocolate-associated chamber, and the number of cataplexy-like behaviors significantly increased in the chocolate-associated chamber but not in the control chamber. In addition, ORX-AB mice remembered the aversive odor-associated chamber and avoided entering without affecting the number of cataplexy-like behaviors. Finally, similar activation of the nucleus accumbens, a positive emotion-related nucleus, was observed during both spontaneous and chocolate-induced cataplexy behaviors. CONCLUSIONS These results support our hypothesis and will promote the usefulness of a narcolepsy mice model in emotion research and serve as a basis for a better understanding of cataplexy in narcolepsy patients.
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Affiliation(s)
- Mayuko Yoshida
- grid.258333.c0000 0001 1167 1801Department of Physiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Sakuragaoka 8-35-1, Kagoshima, 890-8544 Japan
| | - Koki Yamamoto
- grid.258333.c0000 0001 1167 1801Department of Physiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Sakuragaoka 8-35-1, Kagoshima, 890-8544 Japan
| | - Tomoyuki Kuwaki
- grid.258333.c0000 0001 1167 1801Department of Physiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Sakuragaoka 8-35-1, Kagoshima, 890-8544 Japan
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20
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Kim LJ, Alexandre C, Pho H, Latremoliere A, Polotsky VY, Pham LV. Diet-induced obesity leads to sleep fragmentation independently of the severity of sleep-disordered breathing. J Appl Physiol (1985) 2022; 133:1284-1294. [PMID: 36201322 PMCID: PMC9678416 DOI: 10.1152/japplphysiol.00386.2022] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 09/14/2022] [Accepted: 09/28/2022] [Indexed: 11/22/2022] Open
Abstract
Obesity is associated with sleep-disordered breathing (SDB) and unrefreshing sleep. Residual daytime sleepiness and sleep impairments often persist after SDB treatment in patients with obesity, which suggests an independent effect of obesity on breathing and sleep. However, examining the relationship between sleep architecture and SDB in patients with obesity is complex and can be confounded by multiple factors. The main goal of this study was to examine the relationship between obesity-related changes in sleep architecture and SDB. Sleep recordings were performed in 15 lean C57BL/6J and 17 diet-induced obesity (DIO) mice of the same genetic background. Arousals from sleep and apneas were manually scored. Respiratory arousals were classified as events associated with ≥30% drops in minute ventilation (VE) from baseline. We applied Poincaré analysis of VE during sleep to estimate breathing variability. Obesity augmented the frequency of arousals by 45% and this increase was independent of apneas. Respiratory arousals comprised only 15% of the arousals in both groups of mice. Breathing variability during non-rapid-eye-movment (NREM) sleep was significantly higher in DIO mice, but it was not associated with arousal frequency. Our results suggest that obesity induces sleep fragmentation independently of SDB severity.NEW & NOTEWORTHY Our diet-induced obesity (DIO) model reproduces sleep features of human obesity, including sleep fragmentation, increased apnea frequency, and larger breathing variability. DIO induces sleep fragmentation independently of apnea severity. Sleep fragmentation in DIO mice is mainly attributed to non-respiratory arousals. Increased breathing variability during sleep did not account for the higher arousal frequency in DIO. Our results provide a rationale to examine sleep in patients with obesity even when they are adequately treated for sleep-disordered breathing.
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Affiliation(s)
- Lenise J Kim
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Chloe Alexandre
- Department of Neurosurgery, The Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Huy Pho
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Alban Latremoliere
- Department of Neurosurgery, The Johns Hopkins University School of Medicine, Baltimore, Maryland
- Department of Neuroscience, The Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Vsevolod Y Polotsky
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Luu V Pham
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland
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21
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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.
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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
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22
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Klaus S, Carolan A, O'Rourke D, Kennedy B. What respiratory physicians should know about narcolepsy and other hypersomnias. Breathe (Sheff) 2022; 18:220157. [PMID: 36865656 PMCID: PMC9973529 DOI: 10.1183/20734735.0157-2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 09/22/2022] [Indexed: 11/16/2022] Open
Abstract
Narcolepsy and related central disorders of hypersomnolence may present to the sleep clinic with excessive daytime sleepiness. A strong clinical suspicion and awareness of the diagnostic clues, such as cataplexy, are essential to avoid unnecessary diagnostic delay. This review provides an overview of the epidemiology, pathophysiology, clinical features, diagnostic criteria and management of narcolepsy and related disorders, including idiopathic hypersomnia, Kleine-Levin syndrome (recurrent episodic hypersomnia) and secondary central disorders of hypersomnolence.
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Affiliation(s)
- Stephen Klaus
- Department of Sleep Medicine, St James's Hospital, Dublin, Ireland
| | - Aoife Carolan
- Department of Sleep Medicine, St James's Hospital, Dublin, Ireland
| | - Deirdre O'Rourke
- Department of Sleep Medicine, St James's Hospital, Dublin, Ireland
| | - Barry Kennedy
- Department of Sleep Medicine, St James's Hospital, Dublin, Ireland,Corresponding author: Barry Kennedy ()
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23
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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.
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24
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Yamamoto H, Nagumo Y, Ishikawa Y, Irukayama-Tomobe Y, Namekawa Y, Nemoto T, Tanaka H, Takahashi G, Tokuda A, Saitoh T, Nagase H, Funato H, Yanagisawa M. OX2R-selective orexin agonism is sufficient to ameliorate cataplexy and sleep/wake fragmentation without inducing drug-seeking behavior in mouse model of narcolepsy. PLoS One 2022; 17:e0271901. [PMID: 35867683 PMCID: PMC9307173 DOI: 10.1371/journal.pone.0271901] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 07/08/2022] [Indexed: 11/18/2022] Open
Abstract
Acquired loss of hypothalamic orexin (hypocretin)-producing neurons causes the chronic sleep disorder narcolepsy-cataplexy. Orexin replacement therapy using orexin receptor agonists is expected as a mechanistic treatment for narcolepsy. Orexins act on two receptor subtypes, OX1R and OX2R, the latter being more strongly implicated in sleep/wake regulation. However, it has been unclear whether the activation of only OX2R, or both OX1R and OX2R, is required to replace the endogenous orexin functions in the brain. In the present study, we examined whether the selective activation of OX2R is sufficient to rescue the phenotype of cataplexy and sleep/wake fragmentation in orexin knockout mice. Intracerebroventricular [Ala11, D-Leu15]-orexin-B, a peptidic OX2R-selective agonist, selectively activated OX2R-expressing histaminergic neurons in vivo, whereas intracerebroventricular orexin-A, an OX1R/OX2R non-selective agonist, additionally activated OX1R-positive noradrenergic neurons in vivo. Administration of [Ala11, D-Leu15]-orexin-B extended wake time, reduced state transition frequency between wake and NREM sleep, and reduced the number of cataplexy-like episodes, to the same degree as compared with orexin-A. Furthermore, intracerebroventricular orexin-A but not [Ala11, D-Leu15]-orexin-B induced drug-seeking behaviors in a dose-dependent manner in wild-type mice, suggesting that OX2R-selective agonism has a lower propensity for reinforcing/drug-seeking effects. Collectively, these findings provide a proof-of-concept for safer mechanistic treatment of narcolepsy-cataplexy through OX2R-selective agonism.
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Affiliation(s)
- Hikari Yamamoto
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Yasuyuki Nagumo
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Yukiko Ishikawa
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Yoko Irukayama-Tomobe
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Yukiko Namekawa
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Tsuyoshi Nemoto
- School of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Hiromu Tanaka
- School of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Genki Takahashi
- School of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Akihisa Tokuda
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Tsuyoshi Saitoh
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Hiroshi Nagase
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Hiromasa Funato
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Ibaraki, Japan
- Department of Anatomy, Faculty of Medicine, Toho University, Ota-ku, Tokyo, Japan
| | - Masashi Yanagisawa
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Ibaraki, Japan
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, Texas
- Life Science Center, Tsukuba Advanced Research Alliance, University of Tsukuba, Tsukuba, Ibaraki, Japan
- R&D Center for Frontiers of MIRAI in Policy and Technology, University of Tsukuba, Tsukuba, Ibaraki, Japan
- * E-mail:
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25
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Arthaud S, Villalba M, Blondet C, Morel AL, Peyron C. Effects of sex and estrous cycle on sleep and cataplexy in narcoleptic mice. Sleep 2022; 45:6569391. [DOI: 10.1093/sleep/zsac089] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 03/10/2022] [Indexed: 11/14/2022] Open
Abstract
Abstract
Narcolepsy type 1 (NT1) is a rare neurology disorder caused by the loss of orexin/hypocretin neurons. NT1 is characterized by excessive daytime sleepiness, sleep and wake fragmentation, and cataplexy. These symptoms have been equally described in both women and men, although influences of gender and hormonal cycles have been poorly studied. Unfortunately, most studies with NT1 preclinical mouse models, use only male mice to limit potential variations due to the hormonal cycle. Therefore, whether gender and/or hormonal cycles impact the expression of narcoleptic symptoms remains to be determined. To address this question, we analyzed vigilance states and cataplexy in 20 female and 17 male adult orexin knock-out narcoleptic mice, with half of the females being recorded over multiple days. Mice had access to chocolate to encourage the occurrence of cataplectic episodes. A vaginal smear was performed daily in female mice to establish the state of the estrous cycle (EC) of the previous recorded night. We found that vigilance states were more fragmented in males than females, and that females had less paradoxical sleep (p = 0.0315) but more cataplexy (p = 0.0375). Interestingly, sleep and wake features were unchanged across the female EC, but the total amount of cataplexy was doubled during estrus compared to other stages of the cycle (p = 0.001), due to a large increase in the number of cataplexy episodes (p = 0.0002). Altogether these data highlight sex differences in the expression of narcolepsy symptoms in orexin knock-out mice. Notably, cataplexy occurrence was greatly influenced by estrous cycle. Whether it is due to hormonal changes would need to be further explored.
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Affiliation(s)
- Sébastien Arthaud
- Center for Research in Neuroscience of Lyon (CRNL), SLEEP Team, CNRS UMR 5292, INSERM U1028, Centre Hospitalier le Vinatier—Bâtiment 462—Neurocampus Michel Jouvet , Bron Cedex , France
- University Lyon1 , Lyon , France
| | - Manon Villalba
- Center for Research in Neuroscience of Lyon (CRNL), SLEEP Team, CNRS UMR 5292, INSERM U1028, Centre Hospitalier le Vinatier—Bâtiment 462—Neurocampus Michel Jouvet , Bron Cedex , France
- University Lyon1 , Lyon , France
| | | | - Anne-Laure Morel
- Center for Research in Neuroscience of Lyon (CRNL), SLEEP Team, CNRS UMR 5292, INSERM U1028, Centre Hospitalier le Vinatier—Bâtiment 462—Neurocampus Michel Jouvet , Bron Cedex , France
- University Lyon1 , Lyon , France
| | - Christelle Peyron
- Center for Research in Neuroscience of Lyon (CRNL), SLEEP Team, CNRS UMR 5292, INSERM U1028, Centre Hospitalier le Vinatier—Bâtiment 462—Neurocampus Michel Jouvet , Bron Cedex , France
- University Lyon1 , Lyon , France
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26
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Pizza F, Barateau L, Dauvilliers Y, Plazzi G. The orexin story, sleep and sleep disturbances. J Sleep Res 2022; 31:e13665. [PMID: 35698789 DOI: 10.1111/jsr.13665] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 05/16/2022] [Accepted: 05/17/2022] [Indexed: 01/02/2023]
Abstract
The orexins, also known as hypocretins, are two neuropeptides (orexin A and B or hypocretin 1 and 2) produced by a few thousand neurons located in the lateral hypothalamus that were independently discovered by two research groups in 1998. Those two peptides bind two receptors (orexin/hypocretin receptor 1 and receptor 2) that are widely distributed in the brain and involved in the central physiological regulation of sleep and wakefulness, orexin receptor 2 having the major role in the maintenance of arousal. They are also implicated in a multiplicity of other functions, such as reward seeking, energy balance, autonomic regulation and emotional behaviours. The destruction of orexin neurons is responsible for the sleep disorder narcolepsy with cataplexy (type 1) in humans, and a defect of orexin signalling also causes a narcoleptic phenotype in several animal species. Orexin discovery is unprecedented in the history of sleep research, and pharmacological manipulations of orexin may have multiple therapeutic applications. Several orexin receptor antagonists were recently developed as new drugs for insomnia, and orexin agonists may be the next-generation drugs for narcolepsy. Given the broad range of functions of the orexin system, these drugs might also be beneficial for treating various conditions other than sleep disorders in the near future.
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Affiliation(s)
- Fabio Pizza
- Department of Biomedical and Neuromotor Sciences, 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
| | - 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
| | - 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
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27
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Spinieli RL, Ben Musa R, Cornelius-Green J, Hasser EM, Cummings KJ. Orexin facilitates the ventilatory and behavioral responses of rats to hypoxia. Am J Physiol Regul Integr Comp Physiol 2022; 322:R581-R596. [PMID: 35380477 PMCID: PMC9109809 DOI: 10.1152/ajpregu.00334.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 03/22/2022] [Accepted: 03/30/2022] [Indexed: 02/03/2023]
Abstract
Orexin neurons are sensitive to CO2 and contribute to cardiorespiratory homeostasis as well as sensorimotor control. Whether orexin facilitates respiratory and behavioral responses to acute hypoxia is unclear. We hypothesized that orexin neurons are activated by acute hypoxia and that orexin facilitates the hypoxic ventilatory response (HVR), as well as the arterial blood pressure (ABP) and behavioral (movement) responses to acute hypoxia. We further hypothesized that orexin has greater effects in the active phase of the rat circadian cycle, when orexin neurons have high activity. Using whole body plethysmography with EEG, EMG, and the dual-orexin receptor (OxR) antagonist suvorexant (20 mg/kg ip), we determined the effect of OxR blockade on the respiratory, ABP, and behavioral responses of adult rats to acute, graded hypoxia ([Formula: see text]= 0.15, 0.13, 0.11, and 0.09) and hyperoxic hypercapnia ([Formula: see text]= 0.05; [Formula: see text]= 0.95). OxR blockade had no effect on eupnea. OxR blockade significantly reduced the HVR in both inactive and active phases, with a stronger effect in the active phase. OxR blockade reduced the behavioral response to acute hypoxia in the active phase. The central component of the ventilatory and the ABP responses to hypercapnia were reduced by OxR blockade solely in the inactive phase. In the inactive phase, hypoxia activated ∼10% of orexin neurons in the perifornical hypothalamus. These data suggest that orexin neurons participate in the peripheral chemoreflex to facilitate the ventilatory and behavioral responses to acute hypoxia in rats, particularly in the active phase. Orexin also facilitates central chemoreflex responses to CO2 in the inactive phase.
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Affiliation(s)
- Richard L Spinieli
- Department of Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, Missouri
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri
| | - Ruwaida Ben Musa
- Department of Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, Missouri
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri
| | - Jennifer Cornelius-Green
- Department of Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, Missouri
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri
| | - Eileen M Hasser
- Department of Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, Missouri
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri
| | - Kevin J Cummings
- Department of Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, Missouri
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri
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28
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Fujimoto T, Rikimaru K, Fukuda K, Sugimoto H, Masuda K, Ohyabu N, Banno Y, Tokunaga N, Kawamoto T, Tomata Y, Kumagai Y, Iida M, Nagano Y, Yoneyama-Hirozane M, Shimizu Y, Sasa K, Ishikawa T, Yukitake H, Ito M, Aoyama K, Matsumoto T. Discovery of TAK-925 as a Potent, Selective, and Brain-Penetrant Orexin 2 Receptor Agonist. ACS Med Chem Lett 2022; 13:457-462. [PMID: 35295087 PMCID: PMC8919389 DOI: 10.1021/acsmedchemlett.1c00626] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 02/02/2022] [Indexed: 12/28/2022] Open
Abstract
![]()
TAK-925, a potent,
selective, and brain-penetrant orexin 2 receptor
(OX2R) agonist, [methyl (2R,3S)-3-((methylsulfonyl)amino)-2-(((cis-4-phenylcyclohexyl)oxy)methyl)piperidine-1-carboxylate, 16], was identified through the optimization of compound 2, which was discovered by a high throughput screening (HTS)
campaign. Subcutaneous administration of compound 16 produced
wake-promoting effects in mice during the sleep phase. Compound 16 (TAK-925) is being developed for the treatment of narcolepsy
and other related disorders.
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Affiliation(s)
- Tatsuhiko Fujimoto
- Research, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-Chome, Fujisawa, Kanagawa 251-8555, Japan
| | - Kentaro Rikimaru
- Research, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-Chome, Fujisawa, Kanagawa 251-8555, Japan
| | - Koichiro Fukuda
- Research, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-Chome, Fujisawa, Kanagawa 251-8555, Japan
| | - Hiromichi Sugimoto
- Research, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-Chome, Fujisawa, Kanagawa 251-8555, Japan
| | - Kei Masuda
- Research, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-Chome, Fujisawa, Kanagawa 251-8555, Japan
| | - Norio Ohyabu
- Research, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-Chome, Fujisawa, Kanagawa 251-8555, Japan
| | - Yoshihiro Banno
- Research, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-Chome, Fujisawa, Kanagawa 251-8555, Japan
| | - Norihito Tokunaga
- Research, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-Chome, Fujisawa, Kanagawa 251-8555, Japan
| | - Tetsuji Kawamoto
- Research, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-Chome, Fujisawa, Kanagawa 251-8555, Japan
| | - Yoshihide Tomata
- Research, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-Chome, Fujisawa, Kanagawa 251-8555, Japan
| | - Yasumi Kumagai
- Research, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-Chome, Fujisawa, Kanagawa 251-8555, Japan
| | - Motoo Iida
- Research, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-Chome, Fujisawa, Kanagawa 251-8555, Japan
| | - Yoichi Nagano
- Research, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-Chome, Fujisawa, Kanagawa 251-8555, Japan
| | - Mariko Yoneyama-Hirozane
- Research, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-Chome, Fujisawa, Kanagawa 251-8555, Japan
| | - Yuji Shimizu
- Research, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-Chome, Fujisawa, Kanagawa 251-8555, Japan
| | - Katsunori Sasa
- Research, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-Chome, Fujisawa, Kanagawa 251-8555, Japan
| | - Takashi Ishikawa
- Research, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-Chome, Fujisawa, Kanagawa 251-8555, Japan
| | - Hiroshi Yukitake
- Research, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-Chome, Fujisawa, Kanagawa 251-8555, Japan
| | - Mitsuhiro Ito
- Research, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-Chome, Fujisawa, Kanagawa 251-8555, Japan
| | - Kazunobu Aoyama
- Research, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-Chome, Fujisawa, Kanagawa 251-8555, Japan
| | - Takahiro Matsumoto
- Research, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-Chome, Fujisawa, Kanagawa 251-8555, Japan
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29
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Zhou S, Yamashita A, Su J, Zhang Y, Wang W, Hao L, Yamanaka A, Kuwaki T. Activity of putative orexin neurons during cataplexy. Mol Brain 2022; 15:21. [PMID: 35246205 PMCID: PMC8896372 DOI: 10.1186/s13041-022-00907-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Accepted: 02/20/2022] [Indexed: 12/27/2022] Open
Abstract
It is unclear why orexin-deficient animals, but not wild-type mice, show cataplexy. The current hypothesis predicts simultaneous excitation of cataplexy-inhibiting orexin neurons and cataplexy-inducing amygdala neurons. To test this hypothesis, we measured the activity of putative orexin neurons in orexin-knockout mice during cataplexy episodes using fiber photometry. We created two animal models of orexin-knockout mice with a GCaMP6 fluorescent indicator expressed in putative orexin neurons. We first prepared orexin-knockout mice crossed with transgenic mice carrying a tetracycline-controlled transactivator transgene under the control of the orexin promoter. TetO-GCaMP6 was then introduced into mice via an adeno-associated virus injection or natural crossing. The resulting two models showed restricted expression of GCaMP6 in the hypothalamus, where orexin neurons should be located, and showed excitation to an intruder stress that was similar to that observed in orexin-intact mice in our previous study. The activity of these putative orexin neurons increased immediately before the onset of cataplexy-like behavior but decreased (approximately − 20% of the baseline) during the cataplexy-like episode. We propose that the activity of orexin neurons during cataplexy is moderately inhibited by an unknown mechanism. The absence of cataplexy in wild-type mice may be explained by basal or residual activity-induced orexin release, and emotional stimulus-induced counter activation of orexin neurons may not be necessary. This study will serve as a basis for better treatment of cataplexy in narcolepsy patients.
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Affiliation(s)
- Shi Zhou
- Department of Physiology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, 890-8544, Japan.,Department of Pharmaceutical Toxicology, China Medical University, Shenyang, 110122, Liaoning, China
| | - Akira Yamashita
- Department of Physiology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, 890-8544, Japan
| | - Jingyang Su
- Department of Physiology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, 890-8544, Japan.,Department of Pharmaceutical Toxicology, China Medical University, Shenyang, 110122, Liaoning, China
| | - Yang Zhang
- Department of Physiology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, 890-8544, Japan.,Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, 221002, Jiangsu, China
| | - Wuyang Wang
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, 221002, Jiangsu, China
| | - Liying Hao
- Department of Pharmaceutical Toxicology, China Medical University, Shenyang, 110122, Liaoning, China
| | - Akihiro Yamanaka
- Department of Neuroscience II, Research Institute of Environmental Medicine, Nagoya University, Nagoya, 464-8601, Japan
| | - Tomoyuki Kuwaki
- Department of Physiology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, 890-8544, Japan.
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30
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Appetitive Behavior in the Social Transmission of Food Preference Paradigm Predicts Activation of Orexin-A producing Neurons in a Sex-Dependent Manner. Neuroscience 2022; 481:30-46. [PMID: 34843892 DOI: 10.1016/j.neuroscience.2021.11.032] [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: 06/12/2021] [Revised: 11/17/2021] [Accepted: 11/20/2021] [Indexed: 11/22/2022]
Abstract
Orexin-producing cells in the lateral hypothalamic area have been shown to be involved in a wide variety of behavioral and cognitive functions, including the recall of appetitive associations and a variety of social behaviors. Here, we investigated the role of orexin in the acquisition and recall of socially transmitted food preferences in the rat. Rats were euthanized following either acquisition, short-term recall, or long-term recall of a socially transmitted food preference and their brains were processed for orexin-A and c-Fos expression. We found that while there were no significant differences in c-Fos expression between control and experimental subjects at any of the tested timepoints, females displayed significantly more activity in both orexinergic and non-orexinergic cells in the lateral hypothalamus. In the infralimbic cortex, we found that social behavior was significantly predictive of c-Fos expression, with social behaviors related to olfactory exploration appearing to be particularly influential. We additionally found that appetitive behavior was significantly predictive of orexin-A activity in a sex-dependent matter, with the total amount eaten correlating negatively with orexin-A/c-Fos colocalization in male rats but not female rats. These findings suggest a potential sex-specific role for the orexin system in balancing the stimulation of feeding behavior with the sleep/wake cycle.
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31
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Grady FS, Boes AD, Geerling JC. A Century Searching for the Neurons Necessary for Wakefulness. Front Neurosci 2022; 16:930514. [PMID: 35928009 PMCID: PMC9344068 DOI: 10.3389/fnins.2022.930514] [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: 04/28/2022] [Accepted: 06/15/2022] [Indexed: 11/25/2022] Open
Abstract
Wakefulness is necessary for consciousness, and impaired wakefulness is a symptom of many diseases. The neural circuits that maintain wakefulness remain incompletely understood, as do the mechanisms of impaired consciousness in many patients. In contrast to the influential concept of a diffuse "reticular activating system," the past century of neuroscience research has identified a focal region of the upper brainstem that, when damaged, causes coma. This region contains diverse neuronal populations with different axonal projections, neurotransmitters, and genetic identities. Activating some of these populations promotes wakefulness, but it remains unclear which specific neurons are necessary for sustaining consciousness. In parallel, pharmacological evidence has indicated a role for special neurotransmitters, including hypocretin/orexin, histamine, norepinephrine, serotonin, dopamine, adenosine and acetylcholine. However, genetically targeted experiments have indicated that none of these neurotransmitters or the neurons producing them are individually necessary for maintaining wakefulness. In this review, we emphasize the need to determine the specific subset of brainstem neurons necessary for maintaining arousal. Accomplishing this will enable more precise mapping of wakefulness circuitry, which will be useful in developing therapies for patients with coma and other disorders of arousal.
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Affiliation(s)
- Fillan S Grady
- Geerling Laboratory, Department of Neurology, Iowa Neuroscience Institute, The University of Iowa, Iowa City, IA, United States
| | - Aaron D Boes
- Boes Laboratory, Departments of Pediatrics, Neurology, and Psychiatry, The University of Iowa, Iowa City, IA, United States
| | - Joel C Geerling
- Geerling Laboratory, Department of Neurology, Iowa Neuroscience Institute, The University of Iowa, Iowa City, IA, United States
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Discovery of Orexin 2 Receptor Selective and Dual Orexin Receptor Agonists based on the Tetralin Structure: Switching of Receptor Selectivity by Chirality on the Tetralin Ring. Bioorg Med Chem Lett 2022; 60:128555. [DOI: 10.1016/j.bmcl.2022.128555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Revised: 01/05/2022] [Accepted: 01/13/2022] [Indexed: 11/24/2022]
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Vringer M, Kornum BR. Emerging therapeutic targets for narcolepsy. Expert Opin Ther Targets 2021; 25:559-572. [PMID: 34402358 DOI: 10.1080/14728222.2021.1969361] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 08/13/2021] [Indexed: 01/02/2023]
Abstract
INTRODUCTION Narcolepsy type 1 (NT1) and type 2 (NT2) are chronic sleep disorders primarily characterized by excessive daytime sleepiness (EDS), disturbed sleep-wake regulation, and reduced quality of life. The precise disease mechanism is unclear, but it is certain that in NT1 the hypocretin/orexin (Hcrt) system is affected. Current treatment options are symptomatic - they improve EDS and/or reduce cataplexy. Complete symptom control is relatively rare - particularly problematic is residual daytime sleepiness. AREAS COVERED This review discusses various emerging treatment targets for narcolepsy. The focus is on the Hcrt receptors but included are also wake-promoting pathways, and sleep-stabilization through GABAergic mechanisms. Additionally, we discuss the potential of targeting the likely autoimmune basis of narcolepsy. PubMed and ClinicalTrials.gov was searched through June 2021 for relevant information. EXPERT OPINION Targeting Hcrt receptors has the potential to alleviate narcolepsy symptoms. Results from ongoing drug development programs are promising, but care needs to be taken when evaluating potential side effects. It is still largely unknown what roles Hcrt receptors play in the periphery and how these might be affected by treatment. Immunotherapies could potentially target the core pathophysiology of narcolepsy, but more work is needed to identify the best therapeutic target for this approach.
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Affiliation(s)
- Marieke Vringer
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Psychiatry and Neuropsychology, School of Mental Health and Neuroscience (Mhens), Maastricht University, Maastricht, Netherlands
| | - Birgitte Rahbek Kornum
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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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.
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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
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Sun Y, Tisdale RK, Kilduff TS. Hypocretin/Orexin Receptor Pharmacology and Sleep Phases. FRONTIERS OF NEUROLOGY AND NEUROSCIENCE 2021; 45:22-37. [PMID: 34052813 DOI: 10.1159/000514963] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Accepted: 02/02/2021] [Indexed: 12/15/2022]
Abstract
The hypocretins/orexins are two excitatory neuropeptides, alternately called HCRT1 or orexin-A and HCRT2 or orexin-B, that are the endogenous ligands for two G-protein-coupled receptors, HCRTR1/OX1R and HCRTR2/OX2R. Shortly after the discovery of this system, degeneration of hypocretin/orexin-producing neurons was implicated in the etiology of the sleep disorder narcolepsy. The involvement of this system in a disorder characterized by the loss of control over arousal state boundaries also suggested its role as a critical component of endogenous sleep-wake regulatory circuitry. The broad projections of the hypocretin/orexin-producing neurons, along with differential expression of the two receptors in the projection fields of these neurons, suggest distinct roles for these receptors. While HCRTR1/OX1R is associated with regulation of motivation, reward, and autonomic functions, HCRTR2/OX2R is strongly linked to sleep-wake control. The association of hypocretin/orexin with these physiological processes has led to intense interest in the therapeutic potential of compounds targeting these receptors. Agonists and antagonists for the hypocretin/orexin receptors have shown potential for the treatment of disorders of excessive daytime somnolence and nocturnal hyperarousal, respectively, with the first antagonists approved by the US Food and Drug Administration (FDA) in 2014 and 2019 for the treatment of insomnia. These and related compounds have also been useful tools to advance hypocretin/orexin neurobiology.
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Affiliation(s)
- Yu Sun
- Center for Neuroscience, Biosciences Division, SRI International, Menlo Park, California, USA
| | - Ryan K Tisdale
- Center for Neuroscience, Biosciences Division, SRI International, Menlo Park, California, USA
| | - Thomas S Kilduff
- Center for Neuroscience, Biosciences Division, SRI International, Menlo Park, California, USA
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Structures of active-state orexin receptor 2 rationalize peptide and small-molecule agonist recognition and receptor activation. Nat Commun 2021; 12:815. [PMID: 33547286 PMCID: PMC7864924 DOI: 10.1038/s41467-021-21087-6] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Accepted: 01/05/2021] [Indexed: 02/07/2023] Open
Abstract
Narcolepsy type 1 (NT1) is a chronic neurological disorder that impairs the brain’s ability to control sleep-wake cycles. Current therapies are limited to the management of symptoms with modest effectiveness and substantial adverse effects. Agonists of the orexin receptor 2 (OX2R) have shown promise as novel therapeutics that directly target the pathophysiology of the disease. However, identification of drug-like OX2R agonists has proven difficult. Here we report cryo-electron microscopy structures of active-state OX2R bound to an endogenous peptide agonist and a small-molecule agonist. The extended carboxy-terminal segment of the peptide reaches into the core of OX2R to stabilize an active conformation, while the small-molecule agonist binds deep inside the orthosteric pocket, making similar key interactions. Comparison with antagonist-bound OX2R suggests a molecular mechanism that rationalizes both receptor activation and inhibition. Our results enable structure-based discovery of therapeutic orexin agonists for the treatment of NT1 and other hypersomnia disorders. Agonists of the orexin receptor 2 (OX2R) show promise in the treatment of narcolepsy. Cryo-EM structures of active-state OX2R bound to an endogenous peptide agonist and a small-molecule agonist suggest a molecular mechanism that rationalizes both receptor activation and inhibition.
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Harris T, Bugescu R, Kelly J, Makela A, Sotzen M, Sisk C, Atkin G, Pratt R, Crockett E, Leinninger G. DLK1 Expressed in Mouse Orexin Neurons Modulates Anxio-Depressive Behavior but Not Energy Balance. Brain Sci 2020; 10:brainsci10120975. [PMID: 33322758 PMCID: PMC7764426 DOI: 10.3390/brainsci10120975] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 12/08/2020] [Accepted: 12/09/2020] [Indexed: 11/16/2022] Open
Abstract
Lateral hypothalamic area (LHA) neurons expressing the neuropeptide orexin (OX) are implicated in obesity and anxio-depression. However, these neurons release OX as well as a host of other proteins that might contribute to normal physiology and disease states. We hypothesized that delta-like homolog 1 (DLK1), a protein reported to be co-expressed by all OX neurons, contributes to the regulation of energy balance and/or anxio-depression. Consistent with previous reports, we found that all rat OX neurons co-express DLK1. Yet, in mice and humans only a subset of OX neurons co-expressed DLK1. Since human OX-DLK1 distribution is more similar to mice than rats, mice are a comparable model to assess the human physiologic role of DLK1. We therefore used a viral lesion strategy to selectively delete DLK1 within the LHA of adult mice (DLK1Null) to reveal its role in body weight and behavior. Adult-onset DLK1 deletion had no impact on body weight or ingestive behavior. However, DLK1Null mice engaged in more locomotor activity than control mice and had decreased anxiety and depression measured via the elevated plus maze and forced swim tests. These data suggest that DLK1 expression via DLK1-expressing OX neurons primarily contributes to anxio-depression behaviors without impacting body weight.
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Affiliation(s)
- Tatiyana Harris
- Department of Physiology, Michigan State University, East Lansing, MI 48824, USA; (T.H.); (R.B.); (J.K.); (A.M.); (M.S.)
| | - Raluca Bugescu
- Department of Physiology, Michigan State University, East Lansing, MI 48824, USA; (T.H.); (R.B.); (J.K.); (A.M.); (M.S.)
| | - Jaylyn Kelly
- Department of Physiology, Michigan State University, East Lansing, MI 48824, USA; (T.H.); (R.B.); (J.K.); (A.M.); (M.S.)
| | - Anna Makela
- Department of Physiology, Michigan State University, East Lansing, MI 48824, USA; (T.H.); (R.B.); (J.K.); (A.M.); (M.S.)
| | - Morgan Sotzen
- Department of Physiology, Michigan State University, East Lansing, MI 48824, USA; (T.H.); (R.B.); (J.K.); (A.M.); (M.S.)
| | - Cheryl Sisk
- Neuroscience Program, Department of Psychology, Michigan State University, East Lansing, MI 48824, USA;
| | - Graham Atkin
- Department of Radiology, Michigan State University, East Lansing, MI 48824, USA;
| | - Rebecca Pratt
- Department of Foundational Medical Studies, Oakland University William Beaumont School of Medicine, Rochester, MI 48309, USA;
| | - Elahé Crockett
- Department of Medicine, Michigan State University, East Lansing, MI 48824, USA;
| | - Gina Leinninger
- Department of Physiology, Michigan State University, East Lansing, MI 48824, USA; (T.H.); (R.B.); (J.K.); (A.M.); (M.S.)
- Correspondence:
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Abstract
Twenty-two years after their discovery, the hypocretins (Hcrts), also known as orexins, are two of the most studied peptidergic systems, involved in myriad physiological systems that range from sleep, arousal, motivation, homeostatic regulation, fear, anxiety and learning. A causal relationship between activity of Hcrt and arousal stability was established shortly after their discovery and have led to the development of a new class of drugs to treat insomnia. In this review we discuss the many faces of the Hcrt system and examine recent findings that implicate decreased Hcrt function in the pathogenesis of a number of neuropsychiatric conditions. We also discuss future therapeutic strategies to replace or enhance Hcrt function as a treatment option for these neuropsychiatric conditions.
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Affiliation(s)
- Erica Seigneur
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA
| | - Luis de Lecea
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA
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Li SB, Borniger JC, Yamaguchi H, Hédou J, Gaudilliere B, de Lecea L. Hypothalamic circuitry underlying stress-induced insomnia and peripheral immunosuppression. SCIENCE ADVANCES 2020; 6:eabc2590. [PMID: 32917689 PMCID: PMC11206529 DOI: 10.1126/sciadv.abc2590] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 07/28/2020] [Indexed: 06/11/2023]
Abstract
The neural substrates of insomnia/hyperarousal induced by stress remain unknown. Here, we show that restraint stress leads to hyperarousal associated with strong activation of corticotropin-releasing hormone neurons in the paraventricular nucleus of hypothalamus (CRHPVN) and hypocretin neurons in the lateral hypothalamus (HcrtLH). CRHPVN neurons directly innervate HcrtLH neurons, and optogenetic stimulation of LH-projecting CRHPVN neurons elicits hyperarousal. CRISPR-Cas9-mediated knockdown of the crh gene in CRHPVN neurons abolishes hyperarousal induced by stimulating LH-projecting CRHPVN neurons. Genetic ablation of Hcrt neurons or crh gene knockdown significantly counteracts restraint stress-induced hyperarousal. Single-cell mass cytometry by time of flight (CyTOF) revealed extensive changes to immune cell distribution and functional responses in peripheral blood during hyperarousal upon optogenetic stimulation of CRHPVN neurons simulating stress-induced insomnia. Our findings suggest both central and peripheral systems are synergistically engaged in the response to stress via CRHPVN circuitry.
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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.
- Wu Tsai Neurosciences Institute, Stanford University, Stanford, CA 94305, USA
| | - Jeremy C Borniger
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, 1201 Welch Road, Stanford, CA 94305, USA
- Wu Tsai Neurosciences Institute, Stanford University, Stanford, CA 94305, USA
| | - Hiroshi Yamaguchi
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, 1201 Welch Road, Stanford, CA 94305, USA
- Wu Tsai Neurosciences Institute, Stanford University, Stanford, CA 94305, USA
| | - Julien Hédou
- Department of Perioperative and Pain Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Brice Gaudilliere
- Department of Perioperative and Pain Medicine, Stanford University School of Medicine, 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.
- Wu Tsai Neurosciences Institute, Stanford University, Stanford, CA 94305, USA
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Abstract
PURPOSE OF REVIEW Narcolepsy is a central disorder of hypersomnolence with symptoms of excessive daytime sleepiness, sleep paralysis, and cataplexy. Cataplexy is the sudden loss of muscle tone in either the face, neck, trunk, and/or limbs, leading to a loss of voluntary muscle control. This article reviews recent research on the clinical characteristics of cataplexy. RECENT FINDINGS Longitudinal research in adults suggests that there may be a remission of cataplectic severity after symptom stabilization. First-line treatment options for cataplexy include sodium oxybate and pitolisant, with many drugs such as AXS-12, FT218, and JZP258 under investigation. Patients with cataplexy reported greater limitations of daily activities such as driving and exercise compared to patients without cataplexy. Cataplexy remains a challenge for children and adults with narcolepsy and can interfere with daily activities. There is no cure for narcolepsy, but cataplexy can be well-managed with current and promising new treatment options on the horizon.
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41
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Tang H, Zhu Q, Li W, Qin S, Gong Y, Wang H, Shioda S, Li S, Huang J, Liu B, Fang Y, Liu Y, Wang S, Guo Y, Xia Q, Guo Y, Xu Z. Neurophysiology and Treatment of Disorders of Consciousness Induced by Traumatic Brain Injury: Orexin Signaling as a Potential Therapeutic Target. Curr Pharm Des 2020; 25:4208-4220. [PMID: 31663471 DOI: 10.2174/1381612825666191029101830] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Accepted: 10/21/2019] [Indexed: 02/07/2023]
Abstract
BACKGROUND Traumatic brain injury (TBI) can cause disorders of consciousness (DOC) by impairing the neuronal circuits of the ascending reticular activating system (ARAS) structures, including the hypothalamus, which are responsible for the maintenance of the wakefulness and awareness. However, the effectiveness of drugs targeting ARAS activation is still inadequate, and novel therapeutic modalities are urgently needed. METHODS The goal of this work is to describe the neural loops of wakefulness, and explain how these elements participate in DOC, with emphasis on the identification of potential new therapeutic options for DOC induced by TBI. RESULTS Hypothalamus has been identified as a sleep/wake center, and its anterior and posterior regions have diverse roles in the regulation of the sleep/wake function. In particular, the posterior hypothalamus (PH) possesses several types of neurons, including the orexin neurons in the lateral hypothalamus (LH) with widespread projections to other wakefulness-related regions of the brain. Orexins have been known to affect feeding and appetite, and recently their profound effect on sleep disorders and DOC has been identified. Orexin antagonists are used for the treatment of insomnia, and orexin agonists can be used for narcolepsy. Additionally, several studies demonstrated that the agonists of orexin might be effective in the treatment of DOC, providing novel therapeutic opportunities in this field. CONCLUSION The hypothalamic-centered orexin has been adopted as the point of entry into the system of consciousness control, and modulators of orexin signaling opened several therapeutic opportunities for the treatment of DOC.
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Affiliation(s)
- Huiling Tang
- Acupuncture Research Center, Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Qiumei Zhu
- Acupuncture Research Center, Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Wei Li
- Acupuncture Research Center, Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Siru Qin
- Acupuncture Research Center, Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Yinan Gong
- Acupuncture Research Center, Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Hong Wang
- Acu-moxibustion and Tuina Department, Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Seiji Shioda
- Peptide Drug Innovation, Global Research Center for Innovative Life Science, Hoshi University School of Pharmacy and Pharmaceutical Sciences, 2-4-41 Ebara, Shinagawa, Tokyo 142-8501, Japan
| | - Shanshan Li
- Acupuncture Research Center, Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Jin Huang
- Acupuncture Research Center, Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Baohu Liu
- Department of Rehabilitation, Wangjing Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Yuxin Fang
- Acupuncture Research Center, Tianjin University of Traditional Chinese Medicine, Tianjin, China.,Acu-moxibustion and Tuina Department, Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Yangyang Liu
- Acupuncture Research Center, Tianjin University of Traditional Chinese Medicine, Tianjin, China.,Acu-moxibustion and Tuina Department, Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Shenjun Wang
- Acupuncture Research Center, Tianjin University of Traditional Chinese Medicine, Tianjin, China.,Acu-moxibustion and Tuina Department, Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Yongming Guo
- Acupuncture Research Center, Tianjin University of Traditional Chinese Medicine, Tianjin, China.,Acu-moxibustion and Tuina Department, Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Qing Xia
- Acu-moxibustion and Tuina Department, Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Yi Guo
- Acupuncture Research Center, Tianjin University of Traditional Chinese Medicine, Tianjin, China.,College of Traditional Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Zhifang Xu
- Acupuncture Research Center, Tianjin University of Traditional Chinese Medicine, Tianjin, China.,Acu-moxibustion and Tuina Department, Tianjin University of Traditional Chinese Medicine, Tianjin, China
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42
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Cui SY, Huang YL, Cui XY, Zhao HL, Hu X, Liu YT, Qin Y, Kurban N, Zhang YH. A common neuronal mechanism of hypertension and sleep disturbances in spontaneously hypertensive rats: Role of orexinergic neurons. Prog Neuropsychopharmacol Biol Psychiatry 2020; 100:109902. [PMID: 32109507 DOI: 10.1016/j.pnpbp.2020.109902] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Revised: 01/31/2020] [Accepted: 02/24/2020] [Indexed: 10/24/2022]
Abstract
Epidemiologic studies have shown that sleep disorders are associated with the development of hypertension. The present study investigated dynamic changes in sleep patterns during the development of hypertension across the lifespan in spontaneously hypertensive rats (SHRs) and the neural mechanism that underlies these comorbidities, with a focus on the orexinergic system. Blood pressure in rats was measured using a noninvasive blood pressure tail cuff. Sleep was monitored by electroencephalographic and electromyographic recordings. Immunohistochemistry was used to detect the density and activity of orexinergic neurons in the perifornical nucleus. Hcrt2-SAP (400 or 800 ng) was microinjected in the lateral hypothalamus to lesion orexinergic neurons. Compared with Wistar-Kyoto rats, SHRs exhibited various patterns of sleep disturbances. In SHRs, dynamic changes in hypersomnia in the rats' active phase was not synchronized with the development of hypertension, but hyperarousal in the inactive phase and difficulties in falling asleep were observed concurrently with the development of hypertension. Furthermore, the density and activity of orexinergic neurons in the perifornical nucleus were significantly higher in SHRs than in age-matched Wistar-Kyoto rats. The reduction of orexinergic neurons in the lateral hypothalamus partially ameliorated the development of hypertension and prevented difficulties in falling asleep in SHRs. These results indicate that although the correlation between sleep disturbances and hypertension is very complex, common mechanisms may underlie these comorbidities in SHRs. Overactivity of the orexin system may be one such common mechanism.
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Affiliation(s)
- Su-Ying Cui
- Department of Pharmacology, Peking University, School of Basic Medical Science, 38 Xueyuan Road, Beijing 100191, China
| | - Yuan-Li Huang
- Department of Pharmacology, Peking University, School of Basic Medical Science, 38 Xueyuan Road, Beijing 100191, China
| | - Xiang-Yu Cui
- Department of Pharmacology, Peking University, School of Basic Medical Science, 38 Xueyuan Road, Beijing 100191, China
| | - Hui-Ling Zhao
- Department of Pharmacology, Peking University, School of Basic Medical Science, 38 Xueyuan Road, Beijing 100191, China
| | - Xiao Hu
- Department of Pharmacology, Peking University, School of Basic Medical Science, 38 Xueyuan Road, Beijing 100191, China
| | - Yu-Tong Liu
- Department of Pharmacology, Peking University, School of Basic Medical Science, 38 Xueyuan Road, Beijing 100191, China
| | - Yu Qin
- Department of Pharmacology, Peking University, School of Basic Medical Science, 38 Xueyuan Road, Beijing 100191, China
| | - Nurhumar Kurban
- Department of Pharmacology, Peking University, School of Basic Medical Science, 38 Xueyuan Road, Beijing 100191, China
| | - Yong-He Zhang
- Department of Pharmacology, Peking University, School of Basic Medical Science, 38 Xueyuan Road, Beijing 100191, China.
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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.
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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.
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Rogers AA, Aiani LM, Blanpain LT, Yuxian S, Moore R, Willie JT. Deep brain stimulation of hypothalamus for narcolepsy-cataplexy in mice. Brain Stimul 2020; 13:1305-1316. [PMID: 32320748 DOI: 10.1016/j.brs.2020.04.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 03/25/2020] [Accepted: 04/08/2020] [Indexed: 10/24/2022] Open
Abstract
BACKGROUND Narcolepsy type 1 (NT1, narcolepsy with cataplexy) is a disabling neurological disorder caused by loss of excitatory orexin neurons from the hypothalamus and is characterized by decreased motivation, sleep-wake fragmentation, intrusion of rapid-eye-movement sleep (REMS) during wake, and abrupt loss of muscle tone, called cataplexy, in response to sudden emotions. OBJECTIVE We investigated whether subcortical stimulation, analogous to clinical deep brain stimulation (DBS), would ameliorate NT1 using a validated transgenic mouse model with postnatal orexin neuron degeneration. METHODS Using implanted electrodes in freely behaving mice, the immediate and prolonged effects of DBS were determined upon behavior using continuous video-electroencephalogram-electromyogram (video/EEG/EMG) and locomotor activity, and neural activation in brain sections, using immunohistochemical labeling of the immediate early gene product c-Fos. RESULTS Brief 10-s stimulation to the region of the lateral hypothalamus and zona incerta (LH/ZI) dose-responsively reversed established sleep and cataplexy episodes without negative sequelae. Continuous 3-h stimulation increased ambulation, improved sleep-wake consolidation, and ameliorated cataplexy. Brain c-Fos from mice sacrificed after 90 min of DBS revealed dose-responsive neural activation within wake-active nuclei of the basal forebrain, hypothalamus, thalamus, and ventral midbrain. CONCLUSION Acute and continuous LH/ZI DBS enhanced behavioral state control in a mouse model of NT1, supporting the feasibility of clinical DBS for NT1 and other sleep-wake disorders.
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Affiliation(s)
| | - Lauren M Aiani
- Department of Neurosurgery, Emory University, USA; Department of Neurology, Emory University, USA
| | | | - Sun Yuxian
- Department of Biostatistics and Bioinformatics, Emory University, USA
| | - Renee Moore
- Department of Biostatistics and Bioinformatics, Emory University, USA
| | - Jon T Willie
- Department of Neurosurgery, Emory University, USA; Department of Neurology, Emory University, USA.
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45
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Beuckmann CT, Ueno T, Nakagawa M, Suzuki M, Akasofu S. Preclinical in vivo characterization of lemborexant (E2006), a novel dual orexin receptor antagonist for sleep/wake regulation. Sleep 2020; 42:5421821. [PMID: 30923834 PMCID: PMC6559177 DOI: 10.1093/sleep/zsz076] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Accepted: 03/26/2019] [Indexed: 12/22/2022] Open
Abstract
Study Objectives To present results from in vivo studies underlying the preclinical development of lemborexant (E2006), a novel dual orexin (hypocretin) receptor antagonist for sleep/wake regulation. Methods Rodent (wild-type rats and wild-type and orexin neuron-deficient [orexin/ataxin-3 Tg/+] mice) studies were performed to evaluate the effects of single-dose oral lemborexant (1–300 mg/kg) on orexin-induced increases in plasma adrenocorticotropic hormone (ACTH), locomotor activity, vigilance state measures (wakefulness, nonrapid eye movement [non-REM] sleep, rapid eye movement [REM] sleep), ethanol-induced anesthesia, and motor coordination, and the effects of multiple-dose oral lemborexant (30 mg/kg) on vigilance state measures. Active comparators were almorexant and zolpidem. Pharmacokinetics were assessed after single-dose lemborexant in mice and rats. Results Lemborexant prevented the orexin-promoted increase in ACTH in rats, therefore demonstrating inhibition of the orexin signaling pathway. Furthermore, lemborexant promoted sleep in wild-type mice and rats. Lemborexant promoted REM and non-REM sleep at an equal rate (there was no change in the REM sleep ratio). In contrast, zolpidem reduced REM sleep. The sleep-promoting effect of lemborexant was mediated via the orexin-peptide signaling pathway as demonstrated by a lack of sleep promotion in orexin neuron-deficient mice. Chronic dosing was not associated with a change in effect size or sleep architecture immediately postdosing. Lemborexant did not increase the sedative effects of ethanol or impair motor coordination, showing good safety margin in animals. Pharmacokinetic/pharmacodynamic data for mice and rats were well aligned. Conclusions These findings supported further clinical evaluation (ongoing at this time) of lemborexant as a potential candidate for treating insomnia and other sleep disorders.
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Affiliation(s)
| | - Takashi Ueno
- Drug Metabolism and Pharmacokinetics, Eisai Co., Ltd., Tsukuba, Japan
| | - Makoto Nakagawa
- Neurology Business Group, Discovery, Eisai Co., Ltd., Tsukuba, Japan
| | - Michiyuki Suzuki
- Pharmaceutical Regulatory Affairs Department, Marketing Authorization Group, EA Pharma Co., Ltd., Tokyo, Japan
| | - Shigeru Akasofu
- Neurology Business Group, Discovery, Eisai Co., Ltd., Tsukuba, Japan
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Targeting the Orexin System for Prescription Opioid Use Disorder. Brain Sci 2020; 10:brainsci10040226. [PMID: 32290110 PMCID: PMC7225970 DOI: 10.3390/brainsci10040226] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 04/07/2020] [Accepted: 04/08/2020] [Indexed: 01/09/2023] Open
Abstract
Prescription opioids are potent analgesics that are used for clinical pain management. However, the nonmedical use of these medications has emerged as a major concern because of dramatic increases in abuse and overdose. Therefore, effective strategies to prevent prescription opioid use disorder are urgently needed. The orexin system has been implicated in the regulation of motivation, arousal, and stress, making this system a promising target for the treatment of substance use disorder. This review discusses recent preclinical studies that suggest that orexin receptor blockade could be beneficial for the treatment of prescription opioid use disorder.
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Karnani MM, Schöne C, Bracey EF, González JA, Viskaitis P, Li HT, Adamantidis A, Burdakov D. Role of spontaneous and sensory orexin network dynamics in rapid locomotion initiation. Prog Neurobiol 2020; 187:101771. [PMID: 32058043 PMCID: PMC7086232 DOI: 10.1016/j.pneurobio.2020.101771] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Revised: 01/31/2020] [Accepted: 02/03/2020] [Indexed: 12/04/2022]
Abstract
Appropriate motor control is critical for normal life, and requires hypothalamic hypocretin/orexin neurons (HONs). HONs are slowly regulated by nutrients, but also display rapid (subsecond) activity fluctuations in vivo. The necessity of these activity bursts for sensorimotor control and their roles in specific phases of movement are unknown. Here we show that temporally-restricted optosilencing of spontaneous or sensory-evoked HON bursts disrupts locomotion initiation, but does not affect ongoing locomotion. Conversely, HON optostimulation initiates locomotion with subsecond delays in a frequency-dependent manner. Using 2-photon volumetric imaging of activity of >300 HONs during sensory stimulation and self-initiated locomotion, we identify several locomotion-related HON subtypes, which distinctly predict the probability of imminent locomotion initiation, display distinct sensory responses, and are differentially modulated by food deprivation. By causally linking HON bursts to locomotion initiation, these findings reveal the sensorimotor importance of rapid spontaneous and evoked fluctuations in HON ensemble activity.
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Affiliation(s)
- Mahesh M Karnani
- Department of Health Sciences and Technology, ETH Zürich, Zürich, Switzerland; The Francis Crick Institute, London, UK; Institute of Psychiatry, Psychology & Neuroscience, King's College London, UK.
| | - Cornelia Schöne
- The Francis Crick Institute, London, UK; Systems Neuroscience, University of Göttingen, Germany
| | - Edward F Bracey
- Department of Health Sciences and Technology, ETH Zürich, Zürich, Switzerland; The Francis Crick Institute, London, UK
| | - J Antonio González
- The Francis Crick Institute, London, UK; The Rowett Institute, School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, UK
| | - Paulius Viskaitis
- Department of Health Sciences and Technology, ETH Zürich, Zürich, Switzerland
| | - Han-Tao Li
- Department of Health Sciences and Technology, ETH Zürich, Zürich, Switzerland
| | - Antoine Adamantidis
- Department of Neurology, Inselspital, University of Bern, Switzerland; Department of Biomedical Research, University of Bern, Switzerland
| | - Denis Burdakov
- Department of Health Sciences and Technology, ETH Zürich, Zürich, Switzerland; The Francis Crick Institute, London, UK; Institute of Psychiatry, Psychology & Neuroscience, King's College London, UK; Neuroscience Center Zürich (ZNZ), ETH Zürich and University of Zürich, Zürich, Switzerland
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Jones BE. Arousal and sleep circuits. Neuropsychopharmacology 2020; 45:6-20. [PMID: 31216564 PMCID: PMC6879642 DOI: 10.1038/s41386-019-0444-2] [Citation(s) in RCA: 117] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 05/16/2019] [Accepted: 06/11/2019] [Indexed: 12/20/2022]
Abstract
The principal neurons of the arousal and sleep circuits are comprised by glutamate and GABA neurons, which are distributed within the reticular core of the brain and, through local and distant projections and interactions, regulate cortical activity and behavior across wake-sleep states. These are in turn modulated by the neuromodulatory systems that are comprised by acetylcholine, noradrenaline, dopamine, serotonin, histamine, orexin (hypocretin), and melanin-concentrating hormone (MCH) neurons. Glutamate and GABA neurons are heterogeneous in their profiles of discharge, forming distinct functional cell types by selective or maximal discharge during (1) waking and paradoxical (REM) sleep, (2) during slow wave sleep, (3) during waking, or (4) during paradoxical (REM) sleep. The neuromodulatory systems are each homogeneous in their profile of discharge, the majority discharging maximally during waking and paradoxical sleep or during waking. Only MCH neurons discharge maximally during sleep. They each exert their modulatory influence upon other neurons through excitatory and inhibitory receptors thus effecting a concerted differential change in the functionally different cell groups. Both arousal and sleep circuit neurons are homeostatically regulated as a function of their activity in part through changes in receptors. The major pharmacological agents used for the treatment of wake and sleep disorders act upon GABA and neuromodulatory transmission.
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Affiliation(s)
- Barbara E. Jones
- 0000 0004 1936 8649grid.14709.3bDepartment of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC H3A 2B4 Canada
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Tanaka S, Higuchi M, Seki S, Enomoto A, Kogo M. Orexins modulate membrane excitability in rat trigeminal motoneurons. J Oral Sci 2020; 62:265-270. [DOI: 10.2334/josnusd.19-0141] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Affiliation(s)
- Susumu Tanaka
- First Department of Oral and Maxillofacial Surgery, Graduate School of Dentistry, Osaka University
| | - Masataka Higuchi
- First Department of Oral and Maxillofacial Surgery, Graduate School of Dentistry, Osaka University
| | - Soju Seki
- First Department of Oral and Maxillofacial Surgery, Graduate School of Dentistry, Osaka University
| | - Akifumi Enomoto
- Department of Oral and Maxillofacial Surgery, Faculty of Medicine, Kindai University
| | - Mikihiko Kogo
- First Department of Oral and Maxillofacial Surgery, Graduate School of Dentistry, Osaka University
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TAK-925, an orexin 2 receptor-selective agonist, shows robust wake-promoting effects in mice. Pharmacol Biochem Behav 2019; 187:172794. [DOI: 10.1016/j.pbb.2019.172794] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 10/01/2019] [Accepted: 10/01/2019] [Indexed: 11/21/2022]
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