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Prajapati SK, Ahmed S, Rai V, Gupta SC, Krishnamurthy S. Suvorexant improves mitochondrial dynamics with the regulation of orexinergic and mTOR activation in rats exhibiting PTSD-like symptoms. J Affect Disord 2024; 350:24-38. [PMID: 38185385 DOI: 10.1016/j.jad.2024.01.045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 12/24/2023] [Accepted: 01/03/2024] [Indexed: 01/09/2024]
Abstract
BACKGROUND Increasing evidence suggests that mitochondrial dysfunction plays a significant role in PTSD. However, the exact mechanism is still unclear. Mitochondrial dynamics could be one of the mechanisms, as it is crucial for mitochondrial homeostasis and is widely affected in traumatic situations. Mitochondrial dynamics regulate mitochondrial homeostasis via orexinergic receptors, and it is shown that antagonism of orexinergic receptors attenuates PTSD-like symptoms. Therefore, the present study aimed to determine how orexin antagonists affect mitochondrial dynamics in rats exhibiting PTSD-like symptoms. METHODS Using rats, a stress-re-stress (SRS) model with PTSD-like symptoms was established. On day 2 (D-2), the animals were exposed to variable stressors including 2 h of restraint followed by brief mild foot shock and exposure to 4%halothane. Foot shock was performed as a re-stress from D-8 to D-32 at six-day intervals. RESULTS SRS exposure caused PTSD-like phenotype, hypothalamic-pituitary-adrenal axis dysfunction, activation of mammalian target of rapamycin (mTOR), and mitochondrial-fission-process-1 (MTFP-1). SRS-subjected rats exhibited enhanced expression of fission-regulating proteins, including dynamin-related protein-1 and mitochondrial-fission-protein-1 and reduced expression of fusion-regulating proteins, including optic-atrophy-1 and mitofusin-2, in the amygdala. TEM analysis revealed that SRS exposure further damaged the mitochondria. Treatment with suvorexant with rapamycin significantly mitigated PTSD-like symptoms and improved mitochondrial dynamics in SRS-exposed rats. However, their combination showed a more pronounced effect. Further, suvorexant in combination with rapamycin significantly mitigated mTOR and MTFP-1 activation. Sertraline attenuated PTSD-like symptoms without affecting SRS-induced activation of mTOR and disparity in mitochondrial dynamics. Suvorexant pharmacological effects on mitochondrial biogenesis also involve the mTOR pathway. LIMITATION The role of orexinergic pathway in SRS-induced mitochondrial mitophagy was not explored. CONCLUSIONS Targeting both the orexinergic and mTOR pathways might exert a beneficial synergistic effect for treating PTSD.
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Affiliation(s)
- Santosh Kumar Prajapati
- Neurotherapeutics Laboratory, Department of Pharmaceutical Engineering and Technology, Indian Institute of Technology (Banaras Hindu University), Varanasi 221 005, U.P., India; Department of Neurosurgery and Brain Repair, University of South Florida, Tampa, FL 33613, USA
| | - Sahabuddin Ahmed
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Vipin Rai
- Department of Biochemistry, Institute of Science, Banaras Hindu University, Varanasi 221005, Uttar Pradesh, India
| | - Subhas Chandra Gupta
- Department of Biochemistry, Institute of Science, Banaras Hindu University, Varanasi 221005, Uttar Pradesh, India
| | - Sairam Krishnamurthy
- Neurotherapeutics Laboratory, Department of Pharmaceutical Engineering and Technology, Indian Institute of Technology (Banaras Hindu University), Varanasi 221 005, U.P., India.
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2
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Kron JOZJ, Keenan RJ, Hoyer D, Jacobson LH. Orexin Receptor Antagonism: Normalizing Sleep Architecture in Old Age and Disease. Annu Rev Pharmacol Toxicol 2024; 64:359-386. [PMID: 37708433 DOI: 10.1146/annurev-pharmtox-040323-031929] [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] [Indexed: 09/16/2023]
Abstract
Sleep is essential for human well-being, yet the quality and quantity of sleep reduce as age advances. Older persons (>65 years old) are more at risk of disorders accompanied and/or exacerbated by poor sleep. Furthermore, evidence supports a bidirectional relationship between disrupted sleep and Alzheimer's disease (AD) or related dementias. Orexin/hypocretin neuropeptides stabilize wakefulness, and several orexin receptor antagonists (ORAs) are approved for the treatment of insomnia in adults. Dysregulation of the orexin system occurs in aging and AD, positioning ORAs as advantageous for these populations. Indeed, several clinical studies indicate that ORAs are efficacious hypnotics in older persons and dementia patients and, as in adults, are generally well tolerated. ORAs are likely to be more effective when administered early in sleep/wake dysregulation to reestablish good sleep/wake-related behaviors and reduce the accumulation of dementia-associated proteinopathic substrates. Improving sleep in aging and dementia represents a tremendous opportunity to benefit patients, caregivers, and health systems.
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Affiliation(s)
- Jarrah O-Z J Kron
- The Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia;
| | - Ryan J Keenan
- The Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia;
- Department of Physiology, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
| | - Daniel Hoyer
- The Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia;
- Department of Biochemistry and Pharmacology, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, Victoria, Australia;
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California, USA
| | - Laura H Jacobson
- The Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia;
- Department of Biochemistry and Pharmacology, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, Victoria, Australia;
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3
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Keenan RJ, Daykin H, Metha J, Cornthwaite-Duncan L, Wright DK, Clarke K, Oberrauch S, Brian M, Stephenson S, Nowell CJ, Allocca G, Barnham KJ, Hoyer D, Jacobson LH. Orexin 2 receptor antagonism sex-dependently improves sleep/wakefulness and cognitive performance in tau transgenic mice. Br J Pharmacol 2024; 181:87-106. [PMID: 37553894 DOI: 10.1111/bph.16212] [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: 02/08/2023] [Revised: 07/25/2023] [Accepted: 08/01/2023] [Indexed: 08/10/2023] Open
Abstract
BACKGROUND AND PURPOSE Tau pathology contributes to a bidirectional relationship between sleep disruption and neurodegenerative disease. Tau transgenic rTg4510 mice model tauopathy symptoms, including sleep/wake disturbances, which manifest as marked hyperarousal. This phenotype can be prevented by early transgene suppression; however, whether hyperarousal can be rescued after onset is unknown. EXPERIMENTAL APPROACH Three 8-week experiments were conducted with wild-type and rTg4510 mice after age of onset of hyperarousal (4.5 months): (1) Tau transgene suppression with doxycycline (200 ppm); (2) inactive phase rapid eye movement (REM) sleep enhancement with the dual orexin receptor antagonist suvorexant (50 mg·kg-1 ·day-1 ); or (3) Active phase non-NREM (NREM) and REM sleep enhancement using the selective orexin 2 (OX2 ) receptor antagonist MK-1064 (40 mg·kg-1 ·day-1 ). Sleep was assessed using polysomnography, cognition using the Barnes maze, and tau pathology using immunoblotting and/or immunohistochemistry. KEY RESULTS Tau transgene suppression improved tauopathy and hippocampal-dependent spatial memory, but did not modify hyperarousal. Pharmacological rescue of REM sleep deficits did not improve spatial memory or tau pathology. In contrast, normalising hyperarousal by increasing both NREM and REM sleep via OX2 receptor antagonism restored spatial memory, independently of tauopathy, but only in male rTg4510 mice. OX2 receptor antagonism induced only short-lived hypnotic responses in female rTg4510 mice and did not improve spatial memory, indicating a tau- and sex-dependent disruption of OX2 receptor signalling. CONCLUSIONS AND IMPLICATIONS Pharmacologically reducing hyperarousal corrects tau-induced sleep/wake and cognitive deficits. Tauopathy causes sex-dependent disruptions of OX2 receptor signalling/function, which may have implications for choice of hypnotic therapeutics in tauopathies.
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Affiliation(s)
- Ryan J Keenan
- Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia
- Department of Biochemistry and Pharmacology, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Heather Daykin
- Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia
- Department of Biochemistry and Pharmacology, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Jeremy Metha
- Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia
- Department of Biochemistry and Pharmacology, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, Victoria, Australia
- Department of Finance, Faculty of Business and Economics, The University of Melbourne, Parkville, Victoria, Australia
| | - Linda Cornthwaite-Duncan
- Department of Biochemistry and Pharmacology, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | - David K Wright
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria, Australia
| | - Kyra Clarke
- Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia
| | - Sara Oberrauch
- Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia
- Department of Biochemistry and Pharmacology, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Maddison Brian
- Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia
- Department of Biochemistry and Pharmacology, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Sarah Stephenson
- Bruce Lefroy Centre, Murdoch Children's Research Institute, Parkville, Victoria, Australia
- Department of Paediatrics, The University of Melbourne, Parkville, Victoria, Australia
| | - Cameron J Nowell
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Parkville, Victoria, Australia
| | - Giancarlo Allocca
- Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia
- Department of Biochemistry and Pharmacology, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, Victoria, Australia
- Somnivore Inc. Ltd Pty, Bacchus Marsh, Victoria, Australia
| | - Kevin J Barnham
- Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia
| | - Daniel Hoyer
- Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia
- Department of Biochemistry and Pharmacology, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, Victoria, Australia
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California, USA
| | - Laura H Jacobson
- Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia
- Department of Biochemistry and Pharmacology, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, Victoria, Australia
- Melbourne Dementia Research Centre, Florey Institute of Neuroscience and Mental Health and The University of Melbourne, Parkville, Victoria, Australia
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Najib J, Toderika Y, Dima L. Daridorexant, an Orexin Receptor Antagonist for the Management of Insomnia. Am J Ther 2023; 30:e360-e368. [PMID: 37449930 DOI: 10.1097/mjt.0000000000001647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/18/2023]
Abstract
BACKGROUND Insomnia is a common sleep disorder that is diagnosed primarily by patients' subjective reported symptoms. Daridorexant is a new dual orexin receptor antagonist that was recently approved by Food and Drug Administration for insomnia characterized by difficulty falling asleep and/or maintaining sleep. MECHANISM OF ACTION, PHARMACODYNAMICS, AND PHARMACOKINETICS The orexin neuropeptide signaling system plays a role in wakefulness, and blocking the wake-promoting neuropeptides results in diminished wake signaling, thus exerting a sedative effect using an entirely different mechanism of action than the classical sleep promoting agents. The drug has quick onset of action, high volume of distribution, and high protein binding. Pharmacokinetics and pharmacodynamic parameters were similar in patients of different sex and age and were not significantly affected by race, body size, or mild-to-moderate kidney impairment. Dose limitation to 25 mg in moderate liver impairment and no use in severe liver impairment are recommended. The drug undergoes hepatic CYP3A4 metabolism; thus, caution with strong CYP3A4 inhibitors and inducers is warranted. CLINICAL TRIALS The drug was approved based on phase 3 trials involving study 1 and study 2. Study 1 noted daridorexant at doses of 25 and 50 mg demonstrated a statistically significant improvement in wake time after sleep onset, latency to persistent sleep, and self-reported total sleep time against placebo at months 1 and 3. Similarly in study 2, compared with placebo, the 25 mg dose demonstrated statistically significant improvement in wake time after sleep onset, latency to persistent sleep, and self-reported total sleep time at months 1 and 3. Treatment-emergent adverse events were similar for daridorexant and placebo, with nasopharyngitis and headache most frequently reported. THERAPEUTIC ADVANCE Daridorexant is a novel agent with demonstrated efficacy in sleep onset and maintenance and decrease in daytime sedation. Preliminary results from a 1-year extension study note similar incidences of mild-to-moderate side effects as noted in previous trials. Further studies are needed to establish its place in the pharmacological treatment of insomnia.
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Affiliation(s)
- Jadwiga Najib
- Arnold & Marie Schwartz College of Pharmacy and Health Sciences, Long Island University, Brooklyn, NY; and
| | - Yuliana Toderika
- Arnold & Marie Schwartz College of Pharmacy and Health Sciences, Long Island University, Brooklyn, NY; and
| | - Lorena Dima
- Department of Fundamental Disciplines and Clinical Prevention, Faculty of Medicine, Transilvania University of Brasov, Brasov, Romania
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Morairty SR, Sun Y, Toll L, Bruchas MR, Kilduff TS. Activation of the nociceptin/orphanin-FQ receptor promotes NREM sleep and EEG slow wave activity. Proc Natl Acad Sci U S A 2023; 120:e2214171120. [PMID: 36947514 PMCID: PMC10068791 DOI: 10.1073/pnas.2214171120] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Accepted: 02/13/2023] [Indexed: 03/23/2023] Open
Abstract
Sleep/wake control involves several neurotransmitter and neuromodulatory systems yet the coordination of the behavioral and physiological processes underlying sleep is incompletely understood. Previous studies have suggested that activation of the Nociceptin/orphanin FQ (N/OFQ) receptor (NOPR) reduces locomotor activity and produces a sedation-like effect in rodents. In the present study, we systematically evaluated the efficacy of two NOPR agonists, Ro64-6198 and SR16835, on sleep/wake in rats, mice, and Cynomolgus macaques. We found a profound, dose-related increase in non-Rapid Eye Movement (NREM) sleep and electroencephalogram (EEG) slow wave activity (SWA) and suppression of Rapid Eye Movement sleep (REM) sleep in all three species. At the highest dose tested in rats, the increase in NREM sleep and EEG SWA was accompanied by a prolonged inhibition of REM sleep, hypothermia, and reduced locomotor activity. However, even at the highest dose tested, rats were immediately arousable upon sensory stimulation, suggesting sleep rather than an anesthetic state. NOPR agonism also resulted in increased expression of c-Fos in the anterodorsal preoptic and parastrial nuclei, two GABAergic nuclei that are highly interconnected with brain regions involved in physiological regulation. These results suggest that the N/OFQ-NOPR system may have a previously unrecognized role in sleep/wake control and potential promise as a therapeutic target for the treatment of insomnia.
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Affiliation(s)
- Stephen R. Morairty
- Biosciences Division, Center for Neuroscience, SRI International, Menlo Park, CA94025
| | - Yu Sun
- Biosciences Division, Center for Neuroscience, SRI International, Menlo Park, CA94025
| | - Lawrence Toll
- Biosciences Division, Center for Neuroscience, SRI International, Menlo Park, CA94025
| | - Michael R. Bruchas
- Center for Neurobiology of Addiction, Pain, and Emotion, University of Washington, Seattle, WA98195
- Department of Anesthesiology and Pain Medicine, University of Washington, Seattle, WA98195
- Department of Pharmacology, University of Washington, Seattle, WA98195
| | - Thomas S. Kilduff
- Biosciences Division, Center for Neuroscience, SRI International, Menlo Park, CA94025
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6
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Kersanté F, Purple RJ, Jones MW. The GABA A receptor modulator zolpidem augments hippocampal-prefrontal coupling during non-REM sleep. Neuropsychopharmacology 2023; 48:594-604. [PMID: 35717464 PMCID: PMC9938179 DOI: 10.1038/s41386-022-01355-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 05/25/2022] [Accepted: 05/27/2022] [Indexed: 01/16/2023]
Abstract
Benzodiazepines and 'Z-drugs' (including zolpidem and zopiclone) are GABAA receptor (GABAAR) positive modulators commonly prescribed as hypnotics to treat insomnia and/or anxiety. However, alongside sedation, augmenting GABAAR function may also alter coordinated neuronal activity during sleep, thereby influencing sleep-dependent processes including memory consolidation. We used simultaneous recordings of neural population activity from the medial prelimbic cortex (PrL) and CA1 of the dorsal hippocampus (dCA1) of naturally sleeping rats to detail the effects of zolpidem on network activity during the cardinal oscillations of non-REM sleep. For comparison, we also characterized the effects of diazepam and 4,5,6,7-tetrahydroisoxazolo(5,4-c)pyridin-3-ol (THIP/gaboxadol), which acts predominantly at extra-synaptic GABAARs. Zolpidem and THIP significantly increased the amplitudes of slow-waves, which were attenuated by diazepam. Zolpidem increased hippocampal ripple density whereas diazepam decreased both ripple density and intrinsic frequency. While none of the drugs affected thalamocortical spindles in isolation, zolpidem augmented the temporal coordination between slow-waves and spindles. At the cellular level, analyses of spiking activity from 523 PrL and 579 dCA1 neurons revealed that zolpidem significantly enhanced synchronized pauses in cortical firing during slow-wave down states, while increasing correlated activity within and between dCA1 and PrL populations. Of the drugs compared here, zolpidem was unique in augmenting coordinated activity within and between hippocampus and neocortex during non-REM sleep. Zolpidem's enhancement of hippocampal-prefrontal coupling may reflect the cellular basis of its potential to modulate offline memory processing.
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Affiliation(s)
- Flavie Kersanté
- grid.5337.20000 0004 1936 7603School of Physiology, Pharmacology and Neuroscience, University of Bristol, Biomedical Sciences Building, University Walk, Bristol, BS8 1TD UK
| | - Ross J. Purple
- grid.5337.20000 0004 1936 7603School of Physiology, Pharmacology and Neuroscience, University of Bristol, Biomedical Sciences Building, University Walk, Bristol, BS8 1TD UK
| | - Matthew W. Jones
- grid.5337.20000 0004 1936 7603School of Physiology, Pharmacology and Neuroscience, University of Bristol, Biomedical Sciences Building, University Walk, Bristol, BS8 1TD UK
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Abstract
The hypocretins (Hcrts), also known as orexins, are two neuropeptides produced exclusively in the lateral hypothalamus. They act on two specific receptors that are widely distributed across the brain and involved in a myriad of neurophysiological functions that include sleep, arousal, feeding, reward, fear, anxiety and cognition. Hcrt cell loss in humans leads to narcolepsy with cataplexy (narcolepsy type 1), a disorder characterized by intrusions of sleep into wakefulness, demonstrating that the Hcrt system is nonredundant and essential for sleep/wake stability. The causal link between Hcrts and arousal/wakefulness stabilisation has led to the development of a new class of drugs, Hcrt receptor antagonists to treat insomnia, based on the assumption that blocking orexin-induced arousal will facilitate sleep. This has been clinically validated: currently, two Hcrt receptor antagonists are approved to treat insomnia (suvorexant and lemborexant), with a New Drug Application recently submitted to the US Food and Drug Administration for a third drug (daridorexant). Other therapeutic applications under investigation include reduction of cravings in substance-use disorders and prevention of neurodegenerative disorders such as Alzheimer's disease, given the apparent bidirectional relationship between poor sleep and worsening of the disease. Circuit neuroscience findings suggest that the Hcrt system is a hub that integrates diverse inputs modulating arousal (e.g., circadian rhythms, metabolic status, positive and negative emotions) and conveys this information to multiple output regions. This neuronal architecture explains the wealth of physiological functions associated with Hcrts and highlights the potential of the Hcrt system as a therapeutic target for a number of disorders. We discuss present and future possible applications of drugs targeting the Hcrt system for the treatment of circuit-related neuropsychiatric and neurodegenerative conditions.
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Affiliation(s)
- Laura H Jacobson
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia.,Department of Biochemistry and Pharmacology, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, Victoria, Australia.,Melbourne Dementia Research Centre, The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia
| | - Daniel Hoyer
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia.,Department of Biochemistry and Pharmacology, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, Victoria, Australia.,Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California, USA
| | - Luis de Lecea
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, California, USA
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Keenan RJ, Daykin H, Chu J, Cornthwaite-Duncan L, Allocca G, Hoyer D, Jacobson LH. Differential sleep/wake response and sex effects following acute suvorexant, MK-1064 and zolpidem administration in the rTg4510 mouse model of tauopathy. Br J Pharmacol 2022; 179:3403-3417. [PMID: 35112344 PMCID: PMC9302982 DOI: 10.1111/bph.15813] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2021] [Revised: 01/06/2022] [Accepted: 01/28/2022] [Indexed: 12/02/2022] Open
Abstract
Background and Purpose Transgenic mouse models of tauopathy display prominent sleep/wake disturbances which manifest primarily as a hyperarousal phenotype during the active phase, suggesting that tau pathology contributes to sleep/wake changes. However, no study has yet investigated the effect of sleep‐promoting compounds in these models. Such information has implications for the use of hypnotics as potential therapeutic tools in tauopathy‐related disorders. Experimental Approach This study examined polysomnographic recordings in 6‐6.5‐month‐old male and female rTg4510 mice following acute administration of suvorexant (50 mg·kg−1), MK‐1064 (30 mg·kg−1) or zolpidem (10 mg·kg−1), administered at the commencement of the active phase. Key Results Suvorexant, a dual OX receptor antagonist, promoted REM sleep in rTg4510 mice, without affecting wake or NREM sleep. MK‐1064, a selective OX2 receptor antagonist, reduced wake and increased NREM and total sleep time. MK‐1064 normalised the hyperarousal phenotype of male rTg4510 mice, whereas female rTg4510 mice exhibited a more transient response. Zolpidem, a GABAA receptor positive allosteric modulator, decreased wake and increased NREM sleep in both male and female rTg4510 mice. Of the three compounds, the OX2 receptor antagonist MK‐1064 promoted and normalised physiologically normal sleep, especially in male rTg4510 mice. Conclusions and Implications Our findings indicate that hyperphosphorylated tau accumulation and associated hyperarousal does not significantly alter the responses of tauopathy mouse models to hypnotics. However, the sex differences observed in the sleep/wake response of rTg4510 mice to MK‐1064, but not suvorexant or zolpidem, raise questions about therapeutic implications for the use of OX2 receptor antagonists in human neurodegenerative disorders.
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Affiliation(s)
- Ryan J Keenan
- Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia.,Department of Biochemistry and Pharmacology, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Heather Daykin
- Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia.,Department of Biochemistry and Pharmacology, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Jiahui Chu
- Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia.,Department of Biochemistry and Pharmacology, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Linda Cornthwaite-Duncan
- Department of Biochemistry and Pharmacology, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Giancarlo Allocca
- Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia.,Department of Biochemistry and Pharmacology, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, Victoria, Australia.,Somnivore Inc. Ltd. Pty, Bacchus Marsh, Victoria, Australia
| | - Daniel Hoyer
- Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia.,Department of Biochemistry and Pharmacology, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, Victoria, Australia.,Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California, USA
| | - Laura H Jacobson
- Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia.,Department of Biochemistry and Pharmacology, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, Victoria, Australia.,Melbourne Dementia Research Centre, Florey Institute of Neuroscience and Mental Health and The University of Melbourne, Parkville, Victoria, Australia
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The Dual Orexin Receptor Antagonist DORA-22 Improves Mild Stress-induced Sleep Disruption During the Natural Sleep Phase of Nocturnal Rats. Neuroscience 2021; 463:30-44. [PMID: 33737028 DOI: 10.1016/j.neuroscience.2021.03.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 02/27/2021] [Accepted: 03/01/2021] [Indexed: 12/17/2022]
Abstract
Dual orexinergic antagonists (DORAs) have been recently developed as a pharmacotherapy alternative to established hypnotics. Hypnotics are largely evaluated in preclinical rodent models in the dark/active period yet should be ideally evaluated in the light/inactive period, analogous to when sleep disruption occurs in humans. We describe here the hypnotic efficacy of DORA-22 in rodent models of sleep disturbance produced by cage changes in the light/inactive period. Rats were administered DORA-22 or the GABA receptor-targeting hypnotic eszopiclone early in the light period, then exposed to six hourly clean cage changes with measurements of NREM sleep onset latency. Both compounds initially promoted sleep (hours 1 and 2), with DORA-22 exhibiting a more rapid hypnotic onset; and exhibited extended efficacy, evident six hours after administration in a sleep latencies test. A common complaint concerning hypnotic use is lingering hypersomnolence, and this is a concern in pharmacotherapy of the elderly. A second study was designed to determine a minimal dose of DORA-22 which would initially promote sleep but exhibit minimal extended hypnotic effect.Animals were administered DORA-22, then exposed for six hours to a single cage previously dirtied by a conspecific, followed by return to home cage. EEG measures indicated that all DORA-22 doses largely promoted sleep in the first hour. The lowest dose (1 mg/kg) did not decrease sleep onset latency at the six-hour timepoint, suggesting no residual hypersomnolence. We described here DORA-22 hypnotic efficacy during the normal sleep period of nocturnal rats, and demonstrate that well-chosen (low) hypnotic doses of DORA-22 may be hypnotically effective yet have minimal lingering effects.
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10
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Nonclinical pharmacology of daridorexant: a new dual orexin receptor antagonist for the treatment of insomnia. Psychopharmacology (Berl) 2021; 238:2693-2708. [PMID: 34415378 PMCID: PMC8455402 DOI: 10.1007/s00213-021-05954-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Accepted: 08/03/2021] [Indexed: 12/29/2022]
Abstract
Dual orexin receptor antagonists (DORAs) represent a novel type of sleep medication that provide an alternative to the traditionally used positive allosteric gamma-aminobutyric acid (GABA)-A receptor modulators. Daridorexant is a new DORA that exhibited in phase 3 trials in insomnia not only a beneficial effect on sleep variables, measured objectively and assessed subjectively, but also an improvement in daytime functioning. Daridorexant was discovered through a tailored research program aimed at identifying an optimized sleep-promoting molecule with pharmacokinetic properties appropriate for covering the whole night while avoiding next-morning residual activity at efficacious doses. By specific binding to both orexin receptors, daridorexant inhibits the actions of the wake-promoting orexin (also called hypocretin) neuropeptides. This mechanism avoids a more widespread inhibition of neuronal pathways and associated side effects that are intrinsic to positive allosteric GABA-A receptor modulators. Here, we review the general pharmacology of daridorexant, based on nonclinical pharmacology studies of daridorexant, unpublished or already described, or based on work with other DORAs. Some unique features of daridorexant will be highlighted, such as the promotion of natural and surmountable sleep, the preservation of memory and cognition, the absence of tolerance development or risk of physical dependence, and how it can benefit daytime functioning.
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11
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Neylan TC, Richards A, Metzler TJ, Ruoff LM, Varbel J, O’Donovan A, Sivasubramanian M, Motraghi T, Hlavin J, Batki SL, Inslicht SS, Samuelson K, Morairty SR, Kilduff TS. Acute cognitive effects of the hypocretin receptor antagonist almorexant relative to zolpidem and placebo: a randomized clinical trial. Sleep 2020; 43:zsaa080. [PMID: 32303763 PMCID: PMC7551303 DOI: 10.1093/sleep/zsaa080] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 03/06/2020] [Indexed: 12/18/2022] Open
Abstract
STUDY OBJECTIVES Hypnotic medications can adversely affect behavior during unanticipated awakenings during the night. Animals treated with the hypocretin (Hcrt) receptor antagonist almorexant (ALM) have less acute cognitive impairment compared to the GABAA receptor modulator zolpidem (ZOL). This study aimed to determine whether ALM produces less acute cognitive impairment than ZOL in human subjects. METHODS Healthy, young adult, unmedicated male and female subjects participated in a controlled trial of a single dose of ALM 100 mg (N = 48), ALM 200 mg (N = 53), ZOL 10 mg (N = 49), and placebo (PBO, N = 52). RESULTS ZOL and both doses of ALM produced similar levels of subjective sleepiness and impaired the ability of subjects to remain awake in a dark, low-stimulus setting relative to PBO. For most cognitive measures, performance under ZOL was significantly worse than ALM or PBO. For tasks involving verbal memory or visual-motor coordination, ZOL impaired performance, whereas the two doses of ALM were no different than PBO. For tasks involving higher-order executive function, ZOL produced impairment in processing speed and inhibitory control, whereas the two doses of ALM were no different than PBO. Performance decrements for ALM were less than ZOL but greater than PBO for some reaction time measures. CONCLUSIONS The data provide support for the hypothesis that Hcrt receptor antagonists produce less functional impairment than a benzodiazepine receptor agonist (BzRA). These observations are particularly relevant to patients treated with sedative-hypnotics who are at elevated risk for falls and other untoward events during the intended hours for sleep.
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Affiliation(s)
- Thomas C Neylan
- Department of Psychiatry, University of California San Francisco, San Francisco, CA
- San Francisco Veterans Affairs Medical Center, San Francisco, CA
- Sierra-Pacific Mental Illness Research Educational and Clinical Center, Department of Veterans Affairs, Palo Alto, CA
- Department of Neurology, University of California San Francisco, San Francisco, CA
| | - Anne Richards
- Department of Psychiatry, University of California San Francisco, San Francisco, CA
- San Francisco Veterans Affairs Medical Center, San Francisco, CA
- Sierra-Pacific Mental Illness Research Educational and Clinical Center, Department of Veterans Affairs, Palo Alto, CA
| | - Thomas J Metzler
- Department of Psychiatry, University of California San Francisco, San Francisco, CA
- San Francisco Veterans Affairs Medical Center, San Francisco, CA
- Sierra-Pacific Mental Illness Research Educational and Clinical Center, Department of Veterans Affairs, Palo Alto, CA
| | - Leslie M Ruoff
- Department of Psychiatry, University of California San Francisco, San Francisco, CA
- San Francisco Veterans Affairs Medical Center, San Francisco, CA
- Sierra-Pacific Mental Illness Research Educational and Clinical Center, Department of Veterans Affairs, Palo Alto, CA
| | - Jonathan Varbel
- Department of Psychiatry, University of California San Francisco, San Francisco, CA
- San Francisco Veterans Affairs Medical Center, San Francisco, CA
- Sierra-Pacific Mental Illness Research Educational and Clinical Center, Department of Veterans Affairs, Palo Alto, CA
| | - Aoife O’Donovan
- Department of Psychiatry, University of California San Francisco, San Francisco, CA
- San Francisco Veterans Affairs Medical Center, San Francisco, CA
- Sierra-Pacific Mental Illness Research Educational and Clinical Center, Department of Veterans Affairs, Palo Alto, CA
| | - Melinda Sivasubramanian
- Department of Psychiatry, University of California San Francisco, San Francisco, CA
- San Francisco Veterans Affairs Medical Center, San Francisco, CA
- Sierra-Pacific Mental Illness Research Educational and Clinical Center, Department of Veterans Affairs, Palo Alto, CA
| | - Terri Motraghi
- Department of Psychiatry, University of California San Francisco, San Francisco, CA
- San Francisco Veterans Affairs Medical Center, San Francisco, CA
- Sierra-Pacific Mental Illness Research Educational and Clinical Center, Department of Veterans Affairs, Palo Alto, CA
| | - Jennifer Hlavin
- Department of Psychiatry, University of California San Francisco, San Francisco, CA
- San Francisco Veterans Affairs Medical Center, San Francisco, CA
- Sierra-Pacific Mental Illness Research Educational and Clinical Center, Department of Veterans Affairs, Palo Alto, CA
| | - Steven L Batki
- Department of Psychiatry, University of California San Francisco, San Francisco, CA
- San Francisco Veterans Affairs Medical Center, San Francisco, CA
- Sierra-Pacific Mental Illness Research Educational and Clinical Center, Department of Veterans Affairs, Palo Alto, CA
| | - Sabra S Inslicht
- Department of Psychiatry, University of California San Francisco, San Francisco, CA
- San Francisco Veterans Affairs Medical Center, San Francisco, CA
- Sierra-Pacific Mental Illness Research Educational and Clinical Center, Department of Veterans Affairs, Palo Alto, CA
| | - Kristin Samuelson
- Department of Psychiatry, University of California San Francisco, San Francisco, CA
- San Francisco Veterans Affairs Medical Center, San Francisco, CA
- Sierra-Pacific Mental Illness Research Educational and Clinical Center, Department of Veterans Affairs, Palo Alto, CA
- Department of Psychology, University of Colorado, Colorado Springs, CO
| | - Stephen R Morairty
- Center for Neuroscience, Biosciences Division, SRI International, Menlo Park, CA
| | - Thomas S Kilduff
- Center for Neuroscience, Biosciences Division, SRI International, Menlo Park, CA
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12
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Han Y, Yuan K, Zheng Y, Lu L. Orexin Receptor Antagonists as Emerging Treatments for Psychiatric Disorders. Neurosci Bull 2020; 36:432-448. [PMID: 31782044 PMCID: PMC7142186 DOI: 10.1007/s12264-019-00447-9] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Accepted: 09/27/2019] [Indexed: 12/12/2022] Open
Abstract
Orexins comprise two neuropeptides produced by orexin neurons in the lateral hypothalamus and are released by extensive projections of these neurons throughout the central nervous system. Orexins bind and activate their associated G protein-coupled orexin type 1 receptors (OX1Rs) and OX2Rs and act on numerous physiological processes, such as sleep-wake regulation, feeding, reward, emotion, and motivation. Research on the development of orexin receptor antagonists has dramatically increased with the approval of suvorexant for the treatment of primary insomnia. In the present review, we discuss recent findings on the involvement of the orexin system in the pathophysiology of psychiatric disorders, including sleep disorders, depression, anxiety, and drug addiction. We discuss the actions of orexin receptor antagonists, including selective OX1R antagonists (SORA1s), selective OX2R antagonists (SORA2s), and dual OX1/2R antagonists (DORAs), in the treatment of these disorders based on both preclinical and clinical evidence. SORA2s and DORAs have more pronounced efficacy in the treatment of sleep disorders, whereas SORA1s may be promising for the treatment of anxiety and drug addiction. We also discuss potential challenges and opportunities for the application of orexin receptor antagonists to clinical interventions.
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Affiliation(s)
- Ying Han
- National Institute of Drug Dependence and Beijing Key Laboratory of Drug Dependence, Peking University, Beijing, 100191, China
| | - Kai Yuan
- Peking University Sixth Hospital, Peking University Institute of Mental Health, NHC Key Laboratory of Mental Health (Peking University), National Clinical Research Center for Mental Disorders (Peking University Sixth Hospital), Beijing, 100191, China
- Peking-Tsinghua Center for Life Sciences and PKU-IDG/McGovern Institute for Brain Research, Peking University, Beijing, 100871, China
| | - Yongbo Zheng
- Peking University Sixth Hospital, Peking University Institute of Mental Health, NHC Key Laboratory of Mental Health (Peking University), National Clinical Research Center for Mental Disorders (Peking University Sixth Hospital), Beijing, 100191, China
| | - Lin Lu
- National Institute of Drug Dependence and Beijing Key Laboratory of Drug Dependence, Peking University, Beijing, 100191, China.
- Peking University Sixth Hospital, Peking University Institute of Mental Health, NHC Key Laboratory of Mental Health (Peking University), National Clinical Research Center for Mental Disorders (Peking University Sixth Hospital), Beijing, 100191, China.
- Peking-Tsinghua Center for Life Sciences and PKU-IDG/McGovern Institute for Brain Research, Peking University, Beijing, 100871, China.
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13
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Gamble MC, Katsuki F, McCoy JG, Strecker RE, McKenna JT. The dual orexinergic receptor antagonist DORA-22 improves the sleep disruption and memory impairment produced by a rodent insomnia model. Sleep 2019; 43:5583907. [PMID: 31595304 DOI: 10.1093/sleep/zsz241] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 09/06/2019] [Indexed: 12/16/2022] Open
Abstract
AbstractInsomnia-related sleep disruption can contribute to impaired learning and memory. Treatment of insomnia should ideally improve the sleep profile while minimally affecting mnemonic function, yet many hypnotic drugs (e.g. benzodiazepines) are known to impair memory. Here, we used a rat model of insomnia to determine whether the novel hypnotic drug DORA-22, a dual orexin receptor antagonist, improves mild stress-induced insomnia with minimal effect on memory. Animals were first trained to remember the location of a hidden platform (acquisition) in the Morris Water Maze and then administered DORA-22 (10, 30, or 100 mg/kg doses) or vehicle control. Animals were then subjected to a rodent insomnia model involving two exposures to dirty cages over a 6-hr time period (at time points 0 and 3 hr), followed immediately by a probe trial in which memory of the water maze platform location was evaluated. DORA-22 treatment improved the insomnia-related sleep disruption—wake was attenuated and NREM sleep was normalized. REM sleep amounts were enhanced compared with vehicle treatment for one dose (30 mg/kg). In the first hour of insomnia model exposure, DORA-22 promoted the number and average duration of NREM sleep spindles, which have been previously proposed to play a role in memory consolidation (all doses). Water maze measures revealed probe trial performance improvement for select doses of DORA-22, including increased time spent in the platform quadrant (10 and 30 mg/kg) and time spent in platform location and number of platform crossings (10 mg/kg only). In conclusion, DORA-22 treatment improved insomnia-related sleep disruption and memory consolidation deficits.
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Affiliation(s)
- Mackenzie C Gamble
- Boston VA Research Institute, Inc., Jamaica Plain, MA
- VA Boston Healthcare System, West Roxbury, MA
| | - Fumi Katsuki
- Boston VA Research Institute, Inc., Jamaica Plain, MA
- VA Boston Healthcare System, West Roxbury, MA
- Department of Psychiatry, Harvard Medical School, West Roxbury, MA
| | - John G McCoy
- Boston VA Research Institute, Inc., Jamaica Plain, MA
- VA Boston Healthcare System, West Roxbury, MA
- Neuroscience Program, Stonehill College, Easton, MA
| | - Robert E Strecker
- Boston VA Research Institute, Inc., Jamaica Plain, MA
- VA Boston Healthcare System, West Roxbury, MA
- Department of Psychiatry, Harvard Medical School, West Roxbury, MA
| | - James Timothy McKenna
- Boston VA Research Institute, Inc., Jamaica Plain, MA
- VA Boston Healthcare System, West Roxbury, MA
- Department of Psychiatry, Harvard Medical School, West Roxbury, MA
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14
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Allocca G, Ma S, Martelli D, Cerri M, Del Vecchio F, Bastianini S, Zoccoli G, Amici R, Morairty SR, Aulsebrook AE, Blackburn S, Lesku JA, Rattenborg NC, Vyssotski AL, Wams E, Porcheret K, Wulff K, Foster R, Chan JKM, Nicholas CL, Freestone DR, Johnston LA, Gundlach AL. Validation of 'Somnivore', a Machine Learning Algorithm for Automated Scoring and Analysis of Polysomnography Data. Front Neurosci 2019; 13:207. [PMID: 30936820 PMCID: PMC6431640 DOI: 10.3389/fnins.2019.00207] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Accepted: 02/22/2019] [Indexed: 12/14/2022] Open
Abstract
Manual scoring of polysomnography data is labor-intensive and time-consuming, and most existing software does not account for subjective differences and user variability. Therefore, we evaluated a supervised machine learning algorithm, SomnivoreTM, for automated wake–sleep stage classification. We designed an algorithm that extracts features from various input channels, following a brief session of manual scoring, and provides automated wake-sleep stage classification for each recording. For algorithm validation, polysomnography data was obtained from independent laboratories, and include normal, cognitively-impaired, and alcohol-treated human subjects (total n = 52), narcoleptic mice and drug-treated rats (total n = 56), and pigeons (n = 5). Training and testing sets for validation were previously scored manually by 1–2 trained sleep technologists from each laboratory. F-measure was used to assess precision and sensitivity for statistical analysis of classifier output and human scorer agreement. The algorithm gave high concordance with manual visual scoring across all human data (wake 0.91 ± 0.01; N1 0.57 ± 0.01; N2 0.81 ± 0.01; N3 0.86 ± 0.01; REM 0.87 ± 0.01), which was comparable to manual inter-scorer agreement on all stages. Similarly, high concordance was observed across all rodent (wake 0.95 ± 0.01; NREM 0.94 ± 0.01; REM 0.91 ± 0.01) and pigeon (wake 0.96 ± 0.006; NREM 0.97 ± 0.01; REM 0.86 ± 0.02) data. Effects of classifier learning from single signal inputs, simple stage reclassification, automated removal of transition epochs, and training set size were also examined. In summary, we have developed a polysomnography analysis program for automated sleep-stage classification of data from diverse species. Somnivore enables flexible, accurate, and high-throughput analysis of experimental and clinical sleep studies.
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Affiliation(s)
- Giancarlo Allocca
- The Florey Institute of Neuroscience and Mental Health, Parkville, VIC, Australia.,Somnivore Pty. Ltd., Parkville, VIC, Australia
| | - Sherie Ma
- The Florey Institute of Neuroscience and Mental Health, Parkville, VIC, Australia.,Somnivore Pty. Ltd., Parkville, VIC, Australia
| | - Davide Martelli
- The Florey Institute of Neuroscience and Mental Health, Parkville, VIC, Australia.,Laboratory of Autonomic and Behavioral Physiology, Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Matteo Cerri
- Laboratory of Autonomic and Behavioral Physiology, Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Flavia Del Vecchio
- Laboratory of Autonomic and Behavioral Physiology, Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Stefano Bastianini
- PRISM Laboratory, Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Giovanna Zoccoli
- PRISM Laboratory, Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Roberto Amici
- Laboratory of Autonomic and Behavioral Physiology, Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Stephen R Morairty
- Center for Neuroscience, Biosciences Division, SRI International, Menlo Park, CA, United States
| | - Anne E Aulsebrook
- School of BioSciences, The University of Melbourne, Parkville, VIC, Australia
| | - Shaun Blackburn
- School of Life Sciences, La Trobe University, Bundoora, VIC, Australia
| | - John A Lesku
- School of Life Sciences, La Trobe University, Bundoora, VIC, Australia.,Avian Sleep Group, Max Planck Institute for Ornithology, Seewiesen, Germany
| | - Niels C Rattenborg
- Avian Sleep Group, Max Planck Institute for Ornithology, Seewiesen, Germany
| | - Alexei L Vyssotski
- Institute of Neuroinformatics, University of Zurich and ETH Zurich, Zurich, Switzerland
| | - Emma Wams
- The Sleep and Circadian Neuroscience Institute (SCNi), Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Kate Porcheret
- The Sleep and Circadian Neuroscience Institute (SCNi), Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Katharina Wulff
- The Sleep and Circadian Neuroscience Institute (SCNi), Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Russell Foster
- The Sleep and Circadian Neuroscience Institute (SCNi), Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Julia K M Chan
- Melbourne School of Psychological Sciences, The University of Melbourne, Parkville, VIC, Australia
| | - Christian L Nicholas
- Melbourne School of Psychological Sciences, The University of Melbourne, Parkville, VIC, Australia.,Institute of Breathing and Sleep, Austin Health, Heidelberg, VIC, Australia
| | - Dean R Freestone
- Department of Medicine, St. Vincent's Hospital, The University of Melbourne, Fitzroy, VIC, Australia
| | - Leigh A Johnston
- Biomedical Engineering, The University of Melbourne, Parkville, VIC, Australia.,Florey Department of Neuroscience and Mental Health, The University of Melbourne, Parkville, VIC, Australia
| | - Andrew L Gundlach
- The Florey Institute of Neuroscience and Mental Health, Parkville, VIC, Australia.,Somnivore Pty. Ltd., Parkville, VIC, Australia.,Florey Department of Neuroscience and Mental Health, The University of Melbourne, Parkville, VIC, Australia
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15
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Thomasy HE, Opp MR. Hypocretin Mediates Sleep and Wake Disturbances in a Mouse Model of Traumatic Brain Injury. J Neurotrauma 2019; 36:802-814. [PMID: 30136622 PMCID: PMC6387567 DOI: 10.1089/neu.2018.5810] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Traumatic brain injury (TBI) is a major cause of disability worldwide. Post-TBI sleep and wake disturbances are extremely common and difficult for patients to manage. Sleep and wake disturbances contribute to poor functional and emotional outcomes from TBI, yet effective therapies remain elusive. A more comprehensive understanding of mechanisms underlying post-TBI sleep and wake disturbance will facilitate development of effective pharmacotherapies. Previous research in human patients and animal models indicates that altered hypocretinergic function may be a major contributor to sleep-wake disturbance after TBI. In this study, we further elucidate the role of hypocretin by determining the impact of TBI on sleep-wake behavior of hypocretin knockout (HCRT KO) mice. Adult male C57BL/6J and HCRT KO mice were implanted with electroencephalography recording electrodes, and pre-injury baseline recordings were obtained. Mice were then subjected to either moderate TBI or sham surgery. Additional recordings were obtained and sleep-wake behavior determined at 3, 7, 15, and 30 days after TBI or sham procedures. At baseline, HCRT KO mice had a significantly different sleep-wake phenotype than control C57BL/6J mice. Post-TBI sleep-wake behavior was altered in a genotype-dependent manner: sleep of HCRT KO mice was not altered by TBI, whereas C57BL/6J mice had more non-rapid eye movement sleep, less wakefulness, and more short wake bouts and fewer long wake bouts. Numbers of hypocretin-positive cells were reduced in C57BL/6J mice by TBI. Collectively, these data indicate that the hypocretinergic system is involved in the alterations in sleep-wake behavior that develop after TBI in this model, and suggest potential therapeutic interventions.
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Affiliation(s)
- Hannah E. Thomasy
- Department of Anesthesiology and Pain Medicine, University of Washington, Seattle, Washington
| | - Mark R. Opp
- Department of Anesthesiology and Pain Medicine, University of Washington, Seattle, Washington
- Graduate Program in Neurobiology and Behavior, University of Washington, Seattle, Washington
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16
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McKenna JT, Gamble MC, Anderson‐Chernishof MB, Shah SR, McCoy JG, Strecker RE. A rodent cage change insomnia model disrupts memory consolidation. J Sleep Res 2018; 28:e12792. [PMID: 30461100 DOI: 10.1111/jsr.12792] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Revised: 09/21/2018] [Accepted: 10/18/2018] [Indexed: 11/29/2022]
Affiliation(s)
- James T. McKenna
- Boston VA Research Institute, Inc. Jamaica Plain Massachusetts
- VA Boston Healthcare System West Roxbury Massachusetts
- Department of Psychiatry Harvard Medical School West Roxbury Massachusetts
| | - Mackenzie C. Gamble
- Boston VA Research Institute, Inc. Jamaica Plain Massachusetts
- VA Boston Healthcare System West Roxbury Massachusetts
| | - Marissa B. Anderson‐Chernishof
- Boston VA Research Institute, Inc. Jamaica Plain Massachusetts
- VA Boston Healthcare System West Roxbury Massachusetts
- Department of Psychiatry Harvard Medical School West Roxbury Massachusetts
| | - Sunny R. Shah
- Boston VA Research Institute, Inc. Jamaica Plain Massachusetts
- VA Boston Healthcare System West Roxbury Massachusetts
| | - John G. McCoy
- Boston VA Research Institute, Inc. Jamaica Plain Massachusetts
- VA Boston Healthcare System West Roxbury Massachusetts
- Stonehill College Easton Massachusetts
| | - Robert E. Strecker
- Boston VA Research Institute, Inc. Jamaica Plain Massachusetts
- VA Boston Healthcare System West Roxbury Massachusetts
- Department of Psychiatry Harvard Medical School West Roxbury Massachusetts
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17
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García-Brito S, Aldavert-Vera L, Huguet G, Álvarez A, Kádár E, Segura-Torres P. Increased training compensates for OX1R blockage-impairment of spatial memory and c-Fos expression in different cortical and subcortical areas. Behav Brain Res 2018; 353:21-31. [PMID: 29953904 DOI: 10.1016/j.bbr.2018.05.028] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Revised: 05/21/2018] [Accepted: 05/26/2018] [Indexed: 11/29/2022]
Abstract
It has been suggested that the orexin system modulates learning and memory-related processes. However, the possible influence that training could have on the effect of the blockade of orexin-A selective receptor (OX1R) on a spatial memory task has not been explored. Therefore, the present study attempts to compare the effects of OX1R antagonist SB-334867 infusion on spatial memory in two different conditions in the Morris Water Maze (MWM). This experiment evaluated the animals' performance in weak training (2 trials per session) vs strong training (6 trials per session) protocols in a spatial version of the MWM. We found that in the 2-trial condition the post-training SB-334867 infusion had a negative effect on consolidation as well as on the retention and reversal learning of the task 72 h later. This effect was not apparent in the 6-trial condition. In addition, while the strong training groups showed a general increase in c-Fos expression in several brain areas of the hippocampal-thalamic-cortical circuit, SB-334867 administration had the opposite effect in areas that have been previously reported to have a high density of OX1R. Specifically, the SB-infused group in the 2-trial condition showed a decrease in c-Fos immunoreactivity in the dentate gyrus, granular retrosplenial and prelimbic cortices, and centrolateral thalamic nucleus. This was not observed for subjects in the 6-trial condition. The activation of these areas could constitute a neuroanatomical substrate involved in the compensatory mechanisms of training upon SB-334867 impairing effects on a MWM spatial task.
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Affiliation(s)
- Soleil García-Brito
- Universitat Autónoma de Barcelona, Departament de Psicobiologia i de Metodologia de les Ciències de la Salut, Institut de Neurociències, 08193 Bellaterra, Barcelona, Spain.
| | - Laura Aldavert-Vera
- Universitat Autónoma de Barcelona, Departament de Psicobiologia i de Metodologia de les Ciències de la Salut, Institut de Neurociències, 08193 Bellaterra, Barcelona, Spain
| | - Gemma Huguet
- Universitat de Girona, Departament de Biologia, 17071 Girona, Spain
| | - Adam Álvarez
- Universitat Autónoma de Barcelona, Departament de Psicobiologia i de Metodologia de les Ciències de la Salut, Institut de Neurociències, 08193 Bellaterra, Barcelona, Spain
| | - Elisabet Kádár
- Universitat de Girona, Departament de Biologia, 17071 Girona, Spain
| | - Pilar Segura-Torres
- Universitat Autónoma de Barcelona, Departament de Psicobiologia i de Metodologia de les Ciències de la Salut, Institut de Neurociències, 08193 Bellaterra, Barcelona, Spain
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18
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Herring WJ, Roth T, Krystal AD, Michelson D. Orexin receptor antagonists for the treatment of insomnia and potential treatment of other neuropsychiatric indications. J Sleep Res 2018; 28:e12782. [DOI: 10.1111/jsr.12782] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 09/06/2018] [Accepted: 09/22/2018] [Indexed: 01/06/2023]
Affiliation(s)
| | - Thomas Roth
- Sleep Disorders and Research Center Henry Ford Hospital Detroit MI USA
| | - Andrew D. Krystal
- Department of Psychiatry University of California San Francisco California USA
| | - David Michelson
- Clinical ResearchMerck & Co., Inc. Kenilworth New Jersey USA
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19
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Coleman PJ, Gotter AL, Herring WJ, Winrow CJ, Renger JJ. The Discovery of Suvorexant, the First Orexin Receptor Drug for Insomnia. Annu Rev Pharmacol Toxicol 2017; 57:509-533. [PMID: 27860547 DOI: 10.1146/annurev-pharmtox-010716-104837] [Citation(s) in RCA: 86] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Historically, pharmacological therapies have used mechanisms such as γ-aminobutyric acid A (GABAA) receptor potentiation to drive sleep through broad suppression of central nervous system activity. With the discovery of orexin signaling loss as the etiology underlying narcolepsy, a disorder associated with hypersomnolence, orexin antagonism emerged as an alternative approach to attenuate orexin-induced wakefulness more selectively. Dual orexin receptor antagonists (DORAs) block the activity of orexin 1 and 2 receptors to both reduce the threshold to transition into sleep and attenuate orexin-mediated arousal. Among DORAs evaluated clinically, suvorexant has pharmacokinetic properties engineered for a plasma half-life appropriate for rapid sleep onset and maintenance at low to moderate doses. Unlike GABAA receptor modulators, DORAs promote both non-rapid eye movement (NREM) and REM sleep, do not disrupt sleep stage-specific quantitative electroencephalogram spectral profiles, and allow somnolence indistinct from normal sleep. The preservation of cognitive performance and the ability to arouse to salient stimuli after DORA administration suggest further advantages over historical therapies.
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Affiliation(s)
- Paul J Coleman
- Department of Medicinal Chemistry, Merck Research Laboratories, West Point, Pennsylvania 19486;
| | - Anthony L Gotter
- Department of Neuroscience, Merck Research Laboratories, West Point, Pennsylvania 19486
| | - W Joseph Herring
- Department of Clinical Neuroscience, Merck Research Laboratories, West Point, Pennsylvania 19486
| | - Christopher J Winrow
- Department of Neuroscience, Merck Research Laboratories, West Point, Pennsylvania 19486
| | - John J Renger
- Department of Neuroscience, Merck Research Laboratories, West Point, Pennsylvania 19486
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Tanaka Y, Aoki I, Ishine T, Renger JJ, Winrow CJ, Hisada S. [Preclinical and clinical results of dual orexin receptor antagonist, suvorexant (BELSOMRA(®)), a novel therapeutic agent for insomnia]. Nihon Yakurigaku Zasshi 2016; 148:46-56. [PMID: 27430679 DOI: 10.1254/fpj.148.46] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
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21
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McDonald T, Liang HA, Sanoja R, Gotter AL, Kuduk SD, Coleman PJ, Smith KM, Winrow CJ, Renger JJ. Pharmacological evaluation of orexin receptor antagonists in preclinical animal models of pain. J Neurogenet 2016; 30:32-41. [DOI: 10.3109/01677063.2016.1171862] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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22
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Thomasy HE, Febinger HY, Ringgold KM, Gemma C, Opp MR. Hypocretinergic and cholinergic contributions to sleep-wake disturbances in a mouse model of traumatic brain injury. Neurobiol Sleep Circadian Rhythms 2016; 2:71-84. [PMID: 31236496 PMCID: PMC6575582 DOI: 10.1016/j.nbscr.2016.03.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Revised: 03/25/2016] [Accepted: 03/28/2016] [Indexed: 12/24/2022] Open
Abstract
Disorders of sleep and wakefulness occur in the majority of individuals who have experienced traumatic brain injury (TBI), with increased sleep need and excessive daytime sleepiness often reported. Behavioral and pharmacological therapies have limited efficacy, in part, because the etiology of post-TBI sleep disturbances is not well understood. Severity of injuries resulting from head trauma in humans is highly variable, and as a consequence so are their sequelae. Here, we use a controlled laboratory model to investigate the effects of TBI on sleep-wake behavior and on candidate neurotransmitter systems as potential mediators. We focus on hypocretin and melanin-concentrating hormone (MCH), hypothalamic neuropeptides important for regulating sleep and wakefulness, and two potential downstream effectors of hypocretin actions, histamine and acetylcholine. Adult male C57BL/6 mice (n=6-10/group) were implanted with EEG recording electrodes and baseline recordings were obtained. After baseline recordings, controlled cortical impact was used to induce mild or moderate TBI. EEG recordings were obtained from the same animals at 7 and 15 days post-surgery. Separate groups of animals (n=6-8/group) were used to determine effects of TBI on the numbers of hypocretin and MCH-producing neurons in the hypothalamus, histaminergic neurons in the tuberomammillary nucleus, and cholinergic neurons in the basal forebrain. At 15 days post-TBI, wakefulness was decreased and NREM sleep was increased during the dark period in moderately injured animals. There were no differences between groups in REM sleep time, nor were there differences between groups in sleep during the light period. TBI effects on hypocretin and cholinergic neurons were such that more severe injury resulted in fewer cells. Numbers of MCH neurons and histaminergic neurons were not altered under the conditions of this study. Thus, we conclude that moderate TBI in mice reduces wakefulness and increases NREM sleep during the dark period, effects that may be mediated by hypocretin-producing neurons and/or downstream cholinergic effectors in the basal forebrain.
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Affiliation(s)
- Hannah E Thomasy
- Graduate Program in Neuroscience, University of Washington, Seattle, WA, United States
| | - Heidi Y Febinger
- Department of Anesthesiology & Pain Medicine, University of Washington, Seattle, WA, United States
| | - Kristyn M Ringgold
- Department of Anesthesiology & Pain Medicine, University of Washington, Seattle, WA, United States
| | - Carmelina Gemma
- Department of Anesthesiology & Pain Medicine, University of Washington, Seattle, WA, United States
| | - Mark R Opp
- Graduate Program in Neuroscience, University of Washington, Seattle, WA, United States.,Department of Anesthesiology & Pain Medicine, University of Washington, Seattle, WA, United States
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Locus Coeruleus and Tuberomammillary Nuclei Ablations Attenuate Hypocretin/Orexin Antagonist-Mediated REM Sleep. eNeuro 2016; 3:eN-NWR-0018-16. [PMID: 27022631 PMCID: PMC4801942 DOI: 10.1523/eneuro.0018-16.2016] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Revised: 02/11/2016] [Accepted: 02/12/2016] [Indexed: 01/13/2023] Open
Abstract
Hypocretin 1 and 2 (Hcrts; also known as orexin A and B), excitatory neuropeptides synthesized in cells located in the tuberal hypothalamus, play a central role in the control of arousal. Hcrt inputs to the locus coeruleus norepinephrine (LC NE) system and the posterior hypothalamic histaminergic tuberomammillary nuclei (TMN HA) are important efferent pathways for Hcrt-induced wakefulness. The LC expresses Hcrt receptor 1 (HcrtR1), whereas HcrtR2 is found in the TMN. Although the dual Hcrt/orexin receptor antagonist almorexant (ALM) decreases wakefulness and increases NREM and REM sleep time, the neural circuitry that mediates these effects is currently unknown. To test the hypothesis that ALM induces sleep by selectively disfacilitating subcortical wake-promoting populations, we ablated LC NE neurons (LCx) or TMN HA neurons (TMNx) in rats using cell-type-specific saporin conjugates and evaluated sleep/wake following treatment with ALM and the GABAA receptor modulator zolpidem (ZOL). Both LCx and TMNx attenuated the promotion of REM sleep by ALM without affecting ALM-mediated increases in NREM sleep. Thus, eliminating either HcrtR1 signaling in the LC or HcrtR2 signaling in the TMN yields similar effects on ALM-induced REM sleep without affecting NREM sleep time. In contrast, neither lesion altered ZOL efficacy on any measure of sleep–wake regulation. These results contrast with those of a previous study in which ablation of basal forebrain cholinergic neurons attenuated ALM-induced increases in NREM sleep time without affecting REM sleep, indicating that Hcrt neurotransmission influences distinct aspects of NREM and REM sleep at different locations in the sleep–wake regulatory network.
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The Dual Hypocretin Receptor Antagonist Almorexant is Permissive for Activation of Wake-Promoting Systems. Neuropsychopharmacology 2016; 41:1144-55. [PMID: 26289145 PMCID: PMC4748439 DOI: 10.1038/npp.2015.256] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Revised: 07/30/2015] [Accepted: 08/11/2015] [Indexed: 01/21/2023]
Abstract
The dual hypocretin receptor (HcrtR) antagonist almorexant (ALM) may promote sleep through selective disfacilitation of wake-promoting systems, whereas benzodiazepine receptor agonists (BzRAs) such as zolpidem (ZOL) induce sleep through general inhibition of neural activity. Previous studies have indicated that HcrtR antagonists cause less-functional impairment than BzRAs. To gain insight into the mechanisms underlying these differential profiles, we compared the effects of ALM and ZOL on functional activation of wake-promoting systems at doses equipotent for sleep induction. Sprague-Dawley rats, implanted for EEG/EMG recording, were orally administered vehicle (VEH), 100 mg/kg ALM, or 100 mg/kg ZOL during their active phase and either left undisturbed or kept awake for 90 min after which their brains were collected. ZOL-treated rats required more stimulation to maintain wakefulness than VEH- or ALM-treated rats. We measured Fos co-expression with markers for wake-promoting cell groups in the lateral hypothalamus (Hcrt), tuberomammillary nuclei (histamine; HA), basal forebrain (acetylcholine; ACh), dorsal raphe (serotonin; 5HT), and singly labeled Fos(+) cells in the locus coeruleus (LC). Following SD, Fos co-expression in Hcrt, HA, and ACh neurons (but not in 5HT neurons) was consistently elevated in VEH- and ALM-treated rats, whereas Fos expression in these neuronal groups was unaffected by SD in ZOL-treated rats. Surprisingly, Fos expression in the LC was elevated in ZOL- but not in VEH- or ALM-treated SD animals. These results indicate that Hcrt signaling is unnecessary for the activation of Hcrt, HA, or ACh wake-active neurons, which may underlie the milder cognitive impairment produced by HcrtR antagonists compared to ZOL.
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Roundtree HM, Simeone TA, Johnson C, Matthews SA, Samson KK, Simeone KA. Orexin Receptor Antagonism Improves Sleep and Reduces Seizures in Kcna1-null Mice. Sleep 2016. [PMID: 26446112 DOI: 10.5665/sleep.5444.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
STUDY OBJECTIVE Comorbid sleep disorders occur in approximately one-third of people with epilepsy. Seizures and sleep disorders have an interdependent relationship where the occurrence of one can exacerbate the other. Orexin, a wake-promoting neuropeptide, is associated with sleep disorder symptoms. Here, we tested the hypothesis that orexin dysregulation plays a role in the comorbid sleep disorder symptoms in the Kcna1-null mouse model of temporal lobe epilepsy. METHODS Rest-activity was assessed using infrared beam actigraphy. Sleep architecture and seizures were assessed using continuous video-electroencephalography-electromyography recordings in Kcna1-null mice treated with vehicle or the dual orexin receptor antagonist, almorexant (100 mg/kg, intraperitoneally). Orexin levels in the lateral hypothalamus/perifornical region (LH/P) and hypothalamic pathology were assessed with immunohistochemistry and oxygen polarography. RESULTS Kcna1-null mice have increased latency to rapid eye movement (REM) sleep onset, sleep fragmentation, and number of wake epochs. The numbers of REM and non-REM (NREM) sleep epochs are significantly reduced in Kcna1-null mice. Severe seizures propagate to the wake-promoting LH/P where injury is apparent (indicated by astrogliosis, blood-brain barrier permeability, and impaired mitochondrial function). The number of orexin-positive neurons is increased in the LH/P compared to wild-type LH/P. Treatment with a dual orexin receptor antagonist significantly increases the number and duration of NREM sleep epochs and reduces the latency to REM sleep onset. Further, almorexant treatment reduces the incidence of severe seizures and overall seizure burden. Interestingly, we report a significant positive correlation between latency to REM onset and seizure burden in Kcna1-null mice. CONCLUSION Dual orexin receptor antagonists may be an effective sleeping aid in epilepsy, and warrants further study on their somnogenic and ant-seizure effects in other epilepsy models.
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Affiliation(s)
| | - Timothy A Simeone
- Pharmacology Department, Creighton University School of Medicine, Omaha, NE
| | - Chaz Johnson
- Pharmacology Department, Creighton University School of Medicine, Omaha, NE
| | | | - Kaeli K Samson
- Pharmacology Department, Creighton University School of Medicine, Omaha, NE
| | - Kristina A Simeone
- Pharmacology Department, Creighton University School of Medicine, Omaha, NE
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Roundtree HM, Simeone TA, Johnson C, Matthews SA, Samson KK, Simeone KA. Orexin Receptor Antagonism Improves Sleep and Reduces Seizures in Kcna1-null Mice. Sleep 2016; 39:357-68. [PMID: 26446112 DOI: 10.5665/sleep.5444] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Accepted: 08/28/2015] [Indexed: 01/14/2023] Open
Abstract
STUDY OBJECTIVE Comorbid sleep disorders occur in approximately one-third of people with epilepsy. Seizures and sleep disorders have an interdependent relationship where the occurrence of one can exacerbate the other. Orexin, a wake-promoting neuropeptide, is associated with sleep disorder symptoms. Here, we tested the hypothesis that orexin dysregulation plays a role in the comorbid sleep disorder symptoms in the Kcna1-null mouse model of temporal lobe epilepsy. METHODS Rest-activity was assessed using infrared beam actigraphy. Sleep architecture and seizures were assessed using continuous video-electroencephalography-electromyography recordings in Kcna1-null mice treated with vehicle or the dual orexin receptor antagonist, almorexant (100 mg/kg, intraperitoneally). Orexin levels in the lateral hypothalamus/perifornical region (LH/P) and hypothalamic pathology were assessed with immunohistochemistry and oxygen polarography. RESULTS Kcna1-null mice have increased latency to rapid eye movement (REM) sleep onset, sleep fragmentation, and number of wake epochs. The numbers of REM and non-REM (NREM) sleep epochs are significantly reduced in Kcna1-null mice. Severe seizures propagate to the wake-promoting LH/P where injury is apparent (indicated by astrogliosis, blood-brain barrier permeability, and impaired mitochondrial function). The number of orexin-positive neurons is increased in the LH/P compared to wild-type LH/P. Treatment with a dual orexin receptor antagonist significantly increases the number and duration of NREM sleep epochs and reduces the latency to REM sleep onset. Further, almorexant treatment reduces the incidence of severe seizures and overall seizure burden. Interestingly, we report a significant positive correlation between latency to REM onset and seizure burden in Kcna1-null mice. CONCLUSION Dual orexin receptor antagonists may be an effective sleeping aid in epilepsy, and warrants further study on their somnogenic and ant-seizure effects in other epilepsy models.
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Affiliation(s)
| | - Timothy A Simeone
- Pharmacology Department, Creighton University School of Medicine, Omaha, NE
| | - Chaz Johnson
- Pharmacology Department, Creighton University School of Medicine, Omaha, NE
| | | | - Kaeli K Samson
- Pharmacology Department, Creighton University School of Medicine, Omaha, NE
| | - Kristina A Simeone
- Pharmacology Department, Creighton University School of Medicine, Omaha, NE
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Abstract
Cortical electroencephalographic activity arises from corticothalamocortical interactions, modulated by wake-promoting monoaminergic and cholinergic input. These wake-promoting systems are regulated by hypothalamic hypocretin/orexins, while GABAergic sleep-promoting nuclei are found in the preoptic area, brainstem and lateral hypothalamus. Although pontine acetylcholine is critical for REM sleep, hypothalamic melanin-concentrating hormone/GABAergic cells may "gate" REM sleep. Daily sleep-wake rhythms arise from interactions between a hypothalamic circadian pacemaker and a sleep homeostat whose anatomical locus has yet to be conclusively defined. Control of sleep and wakefulness involves multiple systems, each of which presents vulnerability to sleep/wake dysfunction that may predispose to physical and/or neuropsychiatric disorders.
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Affiliation(s)
- Michael D Schwartz
- Biosciences Division, Center for Neuroscience, SRI International, 333 Ravenswood Avenue, Menlo Park, CA 94025, USA
| | - Thomas S Kilduff
- Biosciences Division, Center for Neuroscience, SRI International, 333 Ravenswood Avenue, Menlo Park, CA 94025, USA.
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28
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Dittrich L, Morairty SR, Warrier DR, Kilduff TS. Homeostatic sleep pressure is the primary factor for activation of cortical nNOS/NK1 neurons. Neuropsychopharmacology 2015; 40:632-9. [PMID: 25139062 PMCID: PMC4289951 DOI: 10.1038/npp.2014.212] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Revised: 07/14/2014] [Accepted: 07/17/2014] [Indexed: 01/05/2023]
Abstract
Cortical interneurons, immunoreactive for neuronal nitric oxide synthase (nNOS) and the receptor NK1, express the functional activity marker Fos selectively during sleep. NREM sleep 'pressure' is hypothesized to accumulate during waking and to dissipate during sleep. We reported previously that the proportion of Fos(+) cortical nNOS/NK1 neurons is correlated with established electrophysiological markers of sleep pressure. As these markers covary with the amount of NREM sleep, it remained unclear whether cortical nNOS/NK1 neurons are activated to the same degree throughout NREM sleep or whether the extent of their activation is related to the sleep pressure that accrued during the prior waking period. To distinguish between these possibilities, we used hypnotic medications to control the amount of NREM sleep in rats while we varied prior wake duration and the resultant sleep pressure. Drug administration was preceded by 6 h of sleep deprivation (SD) ('high sleep pressure') or undisturbed conditions ('low sleep pressure'). We find that the proportion of Fos(+) cortical nNOS/NK1 neurons was minimal when sleep pressure was low, irrespective of the amount of time spent in NREM sleep. In contrast, a large proportion of cortical nNOS/NK1 neurons was Fos(+) when an equivalent amount of sleep was preceded by SD. We conclude that, although sleep is necessary for cortical nNOS/NK1 neuron activation, the proportion of cells activated is dependent upon prior wake duration.
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Affiliation(s)
- Lars Dittrich
- Center for Neuroscience, Biosciences Division, SRI International, Menlo Park, CA, USA
| | - Stephen R Morairty
- Center for Neuroscience, Biosciences Division, SRI International, Menlo Park, CA, USA
| | - Deepti R Warrier
- Center for Neuroscience, Biosciences Division, SRI International, Menlo Park, CA, USA
| | - Thomas S Kilduff
- Center for Neuroscience, Biosciences Division, SRI International, Menlo Park, CA, USA,Center for Neuroscience, Biosciences Division, SRI International, 333 Ravenswood Ave, Menlo Park, CA 94025, USA, Tel: +1 916 650 859 5509, Fax: +1 916 650 859 3153, E-mail:
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Vazquez-DeRose J, Schwartz MD, Nguyen AT, Warrier DR, Gulati S, Mathew TK, Neylan TC, Kilduff TS. Hypocretin/orexin antagonism enhances sleep-related adenosine and GABA neurotransmission in rat basal forebrain. Brain Struct Funct 2014; 221:923-40. [PMID: 25431268 DOI: 10.1007/s00429-014-0946-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2014] [Accepted: 11/15/2014] [Indexed: 12/31/2022]
Abstract
Hypocretin/orexin (HCRT) neurons provide excitatory input to wake-promoting brain regions including the basal forebrain (BF). The dual HCRT receptor antagonist almorexant (ALM) decreases waking and increases sleep. We hypothesized that HCRT antagonists induce sleep, in part, through disfacilitation of BF neurons; consequently, ALM should have reduced efficacy in BF-lesioned (BFx) animals. To test this hypothesis, rats were given bilateral IgG-192-saporin injections, which predominantly targets cholinergic BF neurons. BFx and intact rats were then given oral ALM, the benzodiazepine agonist zolpidem (ZOL) or vehicle (VEH) at lights-out. ALM was less effective than ZOL at inducing sleep in BFx rats compared to controls. BF adenosine (ADO), γ-amino-butyric acid (GABA), and glutamate levels were then determined via microdialysis from intact, freely behaving rats following oral ALM, ZOL or VEH. ALM increased BF ADO and GABA levels during waking and mixed vigilance states, and preserved sleep-associated increases in GABA under low and high sleep pressure conditions. ALM infusion into the BF also enhanced cortical ADO release, demonstrating that HCRT input is critical for ADO signaling in the BF. In contrast, oral ZOL and BF-infused ZOL had no effect on ADO levels in either BF or cortex. ALM increased BF ADO (an endogenous sleep-promoting substance) and GABA (which is increased during normal sleep), and required an intact BF for maximal efficacy, whereas ZOL blocked sleep-associated BF GABA release, and required no functional contribution from the BF to induce sleep. ALM thus induces sleep by facilitating the neural mechanisms underlying the normal transition to sleep.
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Affiliation(s)
- Jacqueline Vazquez-DeRose
- Biosciences Division, Center for Neuroscience, SRI International, 333 Ravenswood Ave., Menlo Park, CA, 94025, USA
| | - Michael D Schwartz
- Biosciences Division, Center for Neuroscience, SRI International, 333 Ravenswood Ave., Menlo Park, CA, 94025, USA
| | - Alexander T Nguyen
- Biosciences Division, Center for Neuroscience, SRI International, 333 Ravenswood Ave., Menlo Park, CA, 94025, USA
| | - Deepti R Warrier
- Biosciences Division, Center for Neuroscience, SRI International, 333 Ravenswood Ave., Menlo Park, CA, 94025, USA
| | - Srishti Gulati
- Biosciences Division, Center for Neuroscience, SRI International, 333 Ravenswood Ave., Menlo Park, CA, 94025, USA
| | - Thomas K Mathew
- Biosciences Division, Center for Neuroscience, SRI International, 333 Ravenswood Ave., Menlo Park, CA, 94025, USA
| | - Thomas C Neylan
- UCSF San Francisco VA Medical Center/NCIRE, San Francisco, CA, 94121, USA
| | - Thomas S Kilduff
- Biosciences Division, Center for Neuroscience, SRI International, 333 Ravenswood Ave., Menlo Park, CA, 94025, USA.
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Boss C, Roch-Brisbare C, Steiner MA, Treiber A, Dietrich H, Jenck F, von Raumer M, Sifferlen T, Brotschi C, Heidmann B, Williams JT, Aissaoui H, Siegrist R, Gatfield J. Structure-Activity Relationship, Biological, and Pharmacological Characterization of the Proline Sulfonamide ACT-462206: a Potent, Brain-Penetrant Dual Orexin 1/Orexin 2 Receptor Antagonist. ChemMedChem 2014; 9:2486-96. [DOI: 10.1002/cmdc.201402258] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Indexed: 01/16/2023]
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Steiner MA, Winrow CJ. Opportunities and perspectives for developing orexin receptor antagonists. Front Neurosci 2014; 8:158. [PMID: 24971050 PMCID: PMC4054497 DOI: 10.3389/fnins.2014.00158] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Accepted: 05/26/2014] [Indexed: 12/16/2022] Open
Affiliation(s)
- Michel A Steiner
- Actelion Pharmaceuticals Ltd., Department of Central Nervous System (CNS) Pharmacology Allschwil, Switzerland
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