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Spano GM, Cavelli M, Marshall W, Tononi G, Cirelli C. Increase in NREM sleep slow waves following injections of sodium oxybate in the mouse cerebral cortex and the role of somatostatin-positive interneurons. Eur J Neurosci 2024; 59:502-525. [PMID: 36226638 DOI: 10.1111/ejn.15846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 08/14/2022] [Accepted: 09/18/2022] [Indexed: 11/29/2022]
Abstract
The systemic administration of sodium oxybate (SXB), the sodium salt of gamma-hydroxybutyric acid, promotes slow wave activity (SWA, 0.5-4 Hz EEG power) and increases non-rapid eye movement (NREM) sleep. These effects are mediated by the widely expressed GABAb receptors, and thus, the brain areas targeted by SXB remain unclear. Because slow waves are mainly a cortical phenomenon, we tested here whether systemic SXB promotes SWA by acting directly on the cortex. Moreover, because somatostatin (SOM) + cortical interneurons play a key role in SWA generation, we also assessed their contribution to the effects of SXB. In adult SOM-Cre mice, the injection of SXB in left secondary motor cortex increased SWA during NREM sleep in the first 30 min post-injection (11 mice: either sex). SWA, the amplitude and frequency of the slow waves, and the frequency of the OFF periods increased ipsilaterally and contralaterally to the SXB injection in frontal and parietal cortex. All these changes disappeared when the intracortical injection of SXB was preceded by the chemogenetic inhibition of the SOM+ cells. Thus, SXB may promote the slow waves of NREM sleep, at least in part, by acting directly on the cortex, and this effect involves GABAergic SOM+ interneurons. Our working hypothesis is that SXB potentiates the ability of these cells to inhibit all other cortical cell types via a GABAb mechanism, thus promoting the transition from ON to OFF periods during NREM sleep.
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Affiliation(s)
- Giovanna Maria Spano
- Department of Psychiatry, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Matias Cavelli
- Department of Psychiatry, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Departamento de Fisiología de Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - William Marshall
- Department of Psychiatry, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Department of Mathematics and Statistics, Brock University, St. Catharines, Ontario, Canada
| | - Giulio Tononi
- Department of Psychiatry, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Chiara Cirelli
- Department of Psychiatry, University of Wisconsin-Madison, Madison, Wisconsin, USA
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Kilduff TS. The mystery of gamma-hydoxybutyrate efficacy in narcolepsy type 1. Sleep 2023; 46:zsad156. [PMID: 37260387 PMCID: PMC10485562 DOI: 10.1093/sleep/zsad156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Indexed: 06/02/2023] Open
Affiliation(s)
- Thomas S Kilduff
- Center for Neuroscience, Biosciences Division, SRI International, Menlo Park, CA, USA
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Dauvilliers Y, Bogan RK, Šonka K, Partinen M, Foldvary-Schaefer N, Thorpy MJ. Calcium, Magnesium, Potassium, and Sodium Oxybates Oral Solution: A Lower-Sodium Alternative for Cataplexy or Excessive Daytime Sleepiness Associated with Narcolepsy. Nat Sci Sleep 2022; 14:531-546. [PMID: 35378745 PMCID: PMC8976528 DOI: 10.2147/nss.s279345] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 03/08/2022] [Indexed: 11/23/2022] Open
Abstract
Lower-sodium oxybate (LXB) is an oxybate medication approved to treat cataplexy or excessive daytime sleepiness (EDS) in patients with narcolepsy 7 years of age and older in the United States. LXB was developed as an alternative to sodium oxybate (SXB), because the incidence of cardiovascular comorbidities is higher in patients with narcolepsy and there is an elevated cardiovascular risk associated with high sodium consumption. LXB has a unique formulation of calcium, magnesium, potassium, and sodium ions, containing 92% less sodium than SXB. Whereas the active oxybate moiety is the same for LXB and SXB, their pharmacokinetic profiles are not bioequivalent; therefore, a phase 3 trial in participants with narcolepsy was conducted for LXB. This review summarizes the background on oxybate as a therapeutic agent and its potential mechanism of action on the gamma-aminobutyric acid type B (GABAB) receptor at noradrenergic and dopaminergic neurons, as well as at thalamocortical neurons. The rationale leading to the development of LXB as a lower-sodium alternative to SXB and the key efficacy and safety data supporting its approval for both adult and pediatric patients with narcolepsy are also discussed. LXB was approved in August 2021 in the United States for the treatment of idiopathic hypersomnia in adults. Potential future developments in the field of oxybate medications may include novel formulations and expanded indications for other diseases.
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Affiliation(s)
- Yves Dauvilliers
- Sleep and Wake Disorders Centre, Department of Neurology, Gui de Chauliac Hospital, Montpellier, France.,University of Montpellier, INSERM Institute Neuroscience Montpellier (INM), Montpellier, France
| | - Richard K Bogan
- University of South Carolina School of Medicine, Columbia, SC, USA
| | - Karel Šonka
- Department of Neurology, First Faculty of Medicine, Charles University and General University Hospital, Prague, Czech Republic
| | - Markku Partinen
- Helsinki Sleep Clinic, Terveystalo Healthcare, and Department of Clinical Neurosciences, University of Helsinki, Helsinki, Finland
| | | | - Michael J Thorpy
- Department of Neurology, Albert Einstein College of Medicine, Bronx, NY, USA
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Mamelak M. Sleep, Narcolepsy, and Sodium Oxybate. Curr Neuropharmacol 2021; 20:272-291. [PMID: 33827411 PMCID: PMC9413790 DOI: 10.2174/1570159x19666210407151227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Revised: 03/18/2021] [Accepted: 03/24/2021] [Indexed: 11/23/2022] Open
Abstract
Sodium oxybate (SO) has been in use for many decades to treat narcolepsy with cataplexy. It functions as a weak GABAB agonist but also as an energy source for the brain as a result of its metabolism to succinate and as a powerful antioxidant because of its capacity to induce the formation of NADPH. Its actions at thalamic GABAB receptors can induce slow-wave activity, while its actions at GABAB receptors on monoaminergic neurons can induce or delay REM sleep. By altering the balance between monoaminergic and cholinergic neuronal activity, SO uniquely can induce and prevent cataplexy. The formation of NADPH may enhance sleep’s restorative process by accelerating the removal of the reactive oxygen species (ROS), which accumulate during wakefulness. SO improves alertness in normal subjects and in patients with narcolepsy. SO may allay severe psychological stress - an inflammatory state triggered by increased levels of ROS and characterized by cholinergic supersensitivity and monoaminergic deficiency. SO may be able to eliminate the inflammatory state and correct the cholinergic/ monoaminergic imbalance.
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Affiliation(s)
- Mortimer Mamelak
- Department of Psychiatry, Baycrest Hospital, University of Toronto, Toronto, Ontario. Canada
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Wu X, Wang K, Cui S, Wu S, Zhu G, Zhou M. Electroacupuncture Ameliorates Acute Myocardial Ischemia: A Potential Role of the Locus Coeruleus. Evid Based Complement Alternat Med 2020; 2020:4298657. [PMID: 32328129 DOI: 10.1155/2020/4298657] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/12/2019] [Revised: 02/20/2020] [Accepted: 03/06/2020] [Indexed: 01/08/2023]
Abstract
The locus coeruleus (LC) is closely linked with cardiovascular disease. However, whether it mediates the alleviating effect of electroacupuncture (EA) on acute myocardial ischemia (AMI) remains unclear. A rat model of myocardial ischemia was established through occlusion of the left anterior descending coronary artery. Multichannel in vivo recording and other techniques were used to assess neurons in the LC, norepinephrine (NE) and dopamine (DA) levels in central and myocardial tissue, serum levels of inflammatory factors, and cardiac function. After induction of AMI, LC neuron activity increased and the central NE concentrations increased, while those of DA decreased. Moreover, the serum levels of high-sensitivity C-reactive protein (hs-CRP) increased, whereas those of interleukin-10 (IL-10) decreased. However, these effects were reversed by EA. Additionally, LC lesioning affected NE and DA levels in myocardial tissue and weakened the antimyocardial ischemic effect of EA. Collectively, our results indicated that LC is closely related to AMI and plays an important role in the antimyocardial ischemic effect of EA. This mechanism may be related to inhibition of LC neuron activity by EA, which inhibits the release of large amounts of hs-CRP and promotes that of IL-10 in the serum. Besides, after LC lesioning, EA may improve cardiac function by inhibiting the release of large amounts of NE and promoting the release of DA in myocardial tissue.
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Heidbreder A, Dirks C, Ramm M. Therapy for Cataplexy. Curr Treat Options Neurol 2020; 22. [DOI: 10.1007/s11940-020-0619-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Abstract
Purpose of the review
Cataplexy, an involuntary loss of muscle activity triggered by strong emotions is the most impressive symptom in narcolepsy. This review gives an overview of the current understanding of cataplexy and its available treatment options.
Recent findings
With the discovery of hypocretin/orexin, the understanding of the pathophysiology of cataplexy advanced in the past decades. In the recent years, with the development of new anticataplectic agents (e.g., Pitolisant) symptomatic treatment of cataplexy has further improved. Abrupt cessation of anticataplectic medication especially antidepressants increase the risk of status cataplecticus, a virtually continuous series of long-lasting cataplectic attacks.
Summary
Cataplexies still remain an under-recognized phenomenon due to missing diagnostic measures. Treatment for cataplexy still remains symptomatic but new agents with better tolerability and usability are continuously developed. New therapeutic actions either targeting the autoimmune mechanisms underlying orexin cell death or substituting orexin action are promising treatments for the near future.
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Dornbierer DA, Baur DM, Stucky B, Quednow BB, Kraemer T, Seifritz E, Bosch OG, Landolt HP. Neurophysiological signature of gamma-hydroxybutyrate augmented sleep in male healthy volunteers may reflect biomimetic sleep enhancement: a randomized controlled trial. Neuropsychopharmacology 2019; 44:1985-93. [PMID: 30959514 DOI: 10.1038/s41386-019-0382-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 03/25/2019] [Accepted: 04/01/2019] [Indexed: 12/16/2022]
Abstract
Gamma-hydroxybutyrate (GHB) is an endogenous GHB/GABAB receptor agonist, which has demonstrated potency in consolidating sleep and reducing excessive daytime sleepiness in narcolepsy. Little is known whether GHB's efficacy reflects the promotion of physiological sleep mechanisms and no study has investigated its sleep consolidating effects under low sleep pressure. GHB (50 mg/kg p.o.) and placebo were administered in 20 young male volunteers at 2:30 a.m., the time when GHB is typically given in narcolepsy, in a randomized, double-blinded, crossover manner. Drug effects on sleep architecture and electroencephalographic (EEG) sleep spectra were analyzed. In addition, current source density (CSD) analysis was employed to identify the effects of GHB on the brain electrical sources of neuronal oscillations. Moreover, lagged-phase synchronization (LPS) analysis was applied to quantify the functional connectivity among sleep-relevant brain regions. GHB prolonged slow-wave sleep (stage N3) at the cost of rapid eye movement (REM) sleep. Furthermore, it enhanced delta-theta (0.5-8 Hz) activity in NREM and REM sleep, while reducing activity in the spindle frequency range (13-15 Hz) in sleep stage N2. The increase in delta power predominated in medial prefrontal cortex, parahippocampal and fusiform gyri, and posterior cingulate cortex. Theta power was particularly increased in the prefrontal cortex and both temporal poles. Moreover, the brain areas that showed increased theta power after GHB also exhibited increased lagged-phase synchronization among each other. Our study in healthy men revealed distinct similarities between GHB-augmented sleep and physiologically augmented sleep as seen in recovery sleep after prolonged wakefulness. The promotion of the sleep neurophysiological mechanisms by GHB may thus provide a rationale for GHB-induced sleep and waking quality in neuropsychiatric disorders beyond narcolepsy.
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Thorpy MJ, Bogan RK. Update on the pharmacologic management of narcolepsy: mechanisms of action and clinical implications. Sleep Med 2019; 68:97-109. [PMID: 32032921 DOI: 10.1016/j.sleep.2019.09.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 08/29/2019] [Accepted: 09/03/2019] [Indexed: 12/21/2022]
Abstract
Narcolepsy is a chronic, debilitating neurological disorder of sleep-wake state instability. This instability underlies all narcolepsy symptoms, including excessive daytime sleepiness (EDS), symptoms of rapid eye movement (REM) sleep dysregulation (ie, cataplexy, hypnagogic/hypnopompic hallucinations, sleep paralysis), and disrupted nighttime sleep. Several neurotransmitter systems promote wakefulness, and various neural pathways are involved in regulating REM sleep-related muscle atonia, providing multiple targets for pharmacologic intervention to reduce EDS and cataplexy. Medications approved by the US Food and Drug Administration (FDA) for the treatment of EDS in narcolepsy include traditional stimulants (eg, amphetamines, methylphenidate), wake-promoting agents (eg, modafinil, armodafinil), and solriamfetol, which mainly act on dopaminergic and noradrenergic pathways. Sodium oxybate (thought to act via GABAB receptors) is FDA-approved for the treatment of EDS and cataplexy. Pitolisant, a histamine 3 (H3)-receptor antagonist/inverse agonist, is approved by the European Medicines Agency (EMA) for the treatment of narcolepsy with or without cataplexy in adults and by the FDA for the treatment of EDS in adults with narcolepsy. Pitolisant increases the synthesis and release of histamine in the brain and modulates the release of other neurotransmitters (eg, norepinephrine, dopamine). Antidepressants that inhibit reuptake of serotonin and/or norepinephrine are widely used off label to manage cataplexy. In many patients with narcolepsy, combination treatment with medications that act via different neural pathways is necessary for optimal symptom management. Mechanism of action, pharmacokinetics, and abuse potential are important considerations in treatment selection and subsequent medication adjustments to maximize efficacy and mitigate adverse effects in the treatment of patients with narcolepsy.
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Affiliation(s)
- Michael J Thorpy
- Sleep-Wake Disorders Center, Montefiore Medical Center, Albert Einstein College of Medicine, 3411 Wayne Ave, Bronx, NY, 10467, USA.
| | - Richard K Bogan
- SleepMed Inc., Bogan Sleep Consultants, LLC, 1333 Taylor Street, Columbia, SC, USA.
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Szabo ST, Thorpy MJ, Mayer G, Peever JH, Kilduff TS. Neurobiological and immunogenetic aspects of narcolepsy: Implications for pharmacotherapy. Sleep Med Rev 2018; 43:23-36. [PMID: 30503715 DOI: 10.1016/j.smrv.2018.09.006] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 09/22/2018] [Accepted: 09/27/2018] [Indexed: 01/19/2023]
Abstract
Excessive daytime sleepiness (EDS) and cataplexy are common symptoms of narcolepsy, a sleep disorder associated with the loss of hypocretin/orexin (Hcrt) neurons. Although only a few drugs have received regulatory approval for narcolepsy to date, treatment involves diverse medications that affect multiple biochemical targets and neural circuits. Clinical trials have demonstrated efficacy for the following classes of drugs as narcolepsy treatments: alerting medications (amphetamine, methylphenidate, modafinil/armodafinil, solriamfetol [JZP-110]), antidepressants (tricyclic antidepressants, selective serotonin reuptake inhibitors, serotonin-norepinephrine reuptake inhibitors), sodium oxybate, and the H3-receptor inverse agonist/antagonist pitolisant. Enhanced catecholamine availability and regulation of locus coeruleus (LC) norepinephrine (NE) neuron activity is likely central to the therapeutic activity of most of these compounds. LC NE neurons are integral to sleep/wake regulation and muscle tone; reduced excitatory input to the LC due to compromise of Hcrt/orexin neurons (likely due to autoimmune factors) results in LC NE dysregulation and contributes to narcolepsy/cataplexy symptoms. Agents that increase catecholamines and/or LC activity may mitigate EDS and cataplexy by elevating NE regulation of GABAergic inputs from the amygdala. Consequently, novel medications and treatment strategies aimed at preserving and/or modulating Hcrt/orexin-LC circuit integrity are warranted in narcolepsy/cataplexy.
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Affiliation(s)
- Steven T Szabo
- Duke University Medical Center, Durham, NC, USA; Durham Veterans Affairs Medical Center, Durham, NC, USA.
| | | | | | - John H Peever
- University of Toronto, Toronto, Ontario M5S 3G5, Canada.
| | - Thomas S Kilduff
- Center for Neuroscience, Biosciences Division, SRI International, Menlo Park, CA 94025, USA.
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10
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Abstract
The high energy demands of the substantia nigra pars compacta dopaminergic (DASNc) neurons render these neurons vulnerable to degeneration. These energy demands are a function of their long and extensively arborized axons and very large number of transmitter release sites, and are further augmented by their natural pacemaking activity. Pacemaking is driven by the rhythmic entry of Ca2+ into the cell and, while the entry of Ca2+ into the neuron stimulates energy (ATP) production, the extrusion of Ca2+ conversely saps the energy that is generated. DASNc neurons are said to be operating at a delicate equilibrium where any further stress or environmental demand may lead to their decompensation and degeneration. In experimental models of Parkinson’s disease, reducing the energy requirements of these neurons by trimming the size of the neuronal arbor or by impeding the entry of Ca2+ into the cell has been shown to be protective. Increasing the energy supply to these neurons with d-beta-hydroxybutyrate has also been shown to be protective. The use of gammahydroxybutyrate holds great promise as a neuroprotective in Parkinson’s disease because it can act as an energy source for the cell while simultaneously arresting its pacemaking activity and the entry of Ca2+ into the cell. Short clinical trials of gammahydroxybutyrate in Parkinson’s disease have already demonstrated its immediate capacity to significantly reduce daytime fatigue and sleepiness and to improve sleep at night.
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Kamal RM, van Noorden MS, Franzek E, Dijkstra BAG, Loonen AJM, De Jong CAJ. The Neurobiological Mechanisms of Gamma-Hydroxybutyrate Dependence and Withdrawal and Their Clinical Relevance: A Review. Neuropsychobiology 2016; 73:65-80. [PMID: 27003176 DOI: 10.1159/000443173] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Accepted: 11/29/2015] [Indexed: 11/19/2022]
Abstract
OBJECTIVE x03B3;-Hydroxybutyrate (GHB) has gained popularity as a drug of abuse. In the Netherlands the number of patients in treatment for GHB dependence has increased sharply. Clinical presentation of GHB withdrawal can be life threatening. We aim, through this overview, to explore the neurobiological pathways causing GHB dependency and withdrawal, and their implications for treatment choices. METHODS In this work we review the literature discussing the findings from animal models to clinical studies focused on the neurobiological pathways of endogenous but mainly exogenous GHB. RESULTS Chronic abuse of GHB exerts multifarious neurotransmitter and neuromodulator effects on x03B3;-aminobutyric acid (GABA), glutamate, dopamine, serotonin, norepinephrine and cholinergic systems. Moreover, important effects on neurosteroidogenesis and oxytocin release are wielded. GHB acts mainly via a bidirectional effect on GABAB receptors (GABABR; subunits GABAB1 and GABAB2), depending on the subunit of the GIRK (G-protein-dependent ion inwardly rectifying potassium) channel involved, and an indirect effect of the cortical and limbic inputs outside the nucleus accumbens. GHB also activates a specific GHB receptor and β1-subunits of α4-GABAAR. Reversing this complex interaction of neurobiological mechanisms by the abrupt cessation of GHB use results in a withdrawal syndrome with a diversity of symptoms of different intensity, depending on the pattern of GHB abuse. CONCLUSION The GHB withdrawal symptoms cannot be related to a single mechanism or neurological pathway, which implies that different medication combinations are needed for treatment. A single drug class, such as benzodiazepines, gabapentin or antipsychotics, is unlikely to be sufficient to avoid life-threatening complications. Detoxification by means of titration and tapering of pharmaceutical GHB can be considered as a promising treatment that could make polypharmacy redundant.
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Affiliation(s)
- Rama M Kamal
- Nijmegen Institute for Scientist-Practitioners in Addiction (NISPA), Nijmegen, The Netherlands
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Kamal RM, Dijkstra BA, Loonen AJ, De Jong CA. The Effect of Co-occurring Substance Use on Gamma-hydroxybutyric Acid Withdrawal Syndrome. J Addict Med 2016; 10:229-35. [DOI: 10.1097/adm.0000000000000214] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Maitre M, Klein C, Mensah-Nyagan AG. Mechanisms for the Specific Properties of γ-Hydroxybutyrate in Brain. Med Res Rev 2016; 36:363-88. [PMID: 26739481 DOI: 10.1002/med.21382] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Revised: 11/17/2015] [Accepted: 11/25/2015] [Indexed: 12/12/2022]
Abstract
γ-Hydroxybutyrate (GHB) is both a natural brain compound with neuromodulatory properties at central GABAergic synapses (micromolar concentration range) and also a drug (Xyrem(R) ) clinically used for the treatment of various neurological symptoms (millimolar dose range). However, this drug has abuse potential and can be addictive for some patients. Here, we review the basic mechanistic role of endogenous GHB in brain as well as the properties and mechanisms of action for therapeutic clinical doses of exogenous GHB. Several hypotheses are discussed with a preference for a molecular mechanism that conciliates most of the findings available. This conciliatory model may help for the design of GHB-like drugs active at lower doses and devoid of major side effects.
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Affiliation(s)
- Michel Maitre
- Biopathologie de la Myéline, Neuroprotection et Stratégies Thérapeutiques, INSERM U1119, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Bâtiment 3 de la Faculté de Médecine, 11 rue Humann, 67000, Strasbourg, France
| | - Christian Klein
- Biopathologie de la Myéline, Neuroprotection et Stratégies Thérapeutiques, INSERM U1119, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Bâtiment 3 de la Faculté de Médecine, 11 rue Humann, 67000, Strasbourg, France
| | - Ayikoe G Mensah-Nyagan
- Biopathologie de la Myéline, Neuroprotection et Stratégies Thérapeutiques, INSERM U1119, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Bâtiment 3 de la Faculté de Médecine, 11 rue Humann, 67000, Strasbourg, France
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Babkina OV, Poluektov MG, Levin OS. Heterogeneity of excessive daytime sleepiness in Parkinson’s disease. Zh Nevrol Psikhiatr Im S S Korsakova 2016; 116:60-70. [DOI: 10.17116/jnevro20161166260-70] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Abstract
The sleep disorder narcolepsy is caused by the loss of orexinergic neurones in the lateral hypothalamus. A troublesome symptom of narcolepsy is cataplexy, the sudden loss of muscle tone in response to strong emotions. It can be alleviated by antidepressants and sodium oxybate (γ-hydroxybutyric acid (GHB)). It is likely that the noradrenergic nucleus locus coeruleus (LC) is involved since it is essential for the maintenance of muscle tone, and ceases to fire during cataplectic attacks. Furthermore, alpha-2 adrenoceptors proliferate in the LC in cataplexy, probably due to 'heterologous denervation supersensitivity' resulting from the loss/weakening of the orexinergic input to the LC. This would lead to the sensitization of the autoinhibition mechanism of LC neurones mediated by inhibitory alpha-2 adrenoceptors ('autoreceptors'). Thus the excitatory input from the amygdala to the LC, activated by an emotional stimulus, would lead to the 'switching off' of LC activity via the supersensitive auto-inhibition mechanism. GHB is an agonist at both γ-aminobutyric acid (GABA) GABA (B) and GHB receptors that may be a subtype of an extrasynaptic GABA(A) receptor. GHB may prevent a cataplectic attack by dampening the tone of LC neurones via the stimulation of inhibitory extrasynaptic GABA receptors in the LC, and thus increasing the threshold for autoinhibition.
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Affiliation(s)
- Elemer Szabadi
- Developmental Psychiatry, University of Nottingham, Nottingham, UK
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16
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Hodor A, Palchykova S, Gao B, Bassetti CL. Baclofen and gamma-hydroxybutyrate differentially altered behavior, EEG activity and sleep in rats. Neuroscience 2014; 284:18-28. [PMID: 25301745 DOI: 10.1016/j.neuroscience.2014.08.061] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Revised: 08/17/2014] [Accepted: 08/27/2014] [Indexed: 12/29/2022]
Abstract
OBJECTIVES Animal and human studies have shown that sleep may have an impact on functional recovery after brain damage. Baclofen (Bac) and gamma-hydroxybutyrate (GHB) have been shown to induce physiological sleep in humans, however, their effects in rodents are unclear. The aim of this study is to characterize sleep and electroencelphalogram (EEG) after Bac and GHB administration in rats. We hypothesized that both drugs would induce physiological sleep. METHODS Adult male Sprague-Dawley rats were implanted with EEG/electromyogram (EMG) electrodes for sleep recordings. Bac (10 or 20 mg/kg), GHB (150 or 300 mg/kg) or saline were injected 1 h after light and dark onset to evaluate time of day effect of the drugs. Vigilance states and EEG spectra were quantified. RESULTS Bac and GHB induced a non-physiological state characterized by atypical behavior and an abnormal EEG pattern. After termination of this state, Bac was found to increase the duration of non-rapid eye movement (NREM) and rapid eye movement (REM) sleep (∼90 and 10 min, respectively), reduce sleep fragmentation and affect NREM sleep episode frequency and duration (p<0.05). GHB had no major effect on vigilance states. Bac drastically increased EEG power density in NREM sleep in the frequencies 1.5-6.5 and 9.5-21.5 Hz compared to saline (p<0.05), while GHB enhanced power in the 1-5-Hz frequency band and reduced it in the 7-9-Hz band. Slow-wave activity in NREM sleep was enhanced 1.5-3-fold during the first 1-2 h following termination of the non-physiological state. The magnitude of drug effects was stronger during the dark phase. CONCLUSION While both Bac and GHB induced a non-physiological resting state, only Bac facilitated and consolidated sleep, and promoted EEG delta oscillations thereafter. Hence, Bac can be considered a sleep-promoting drug and its effects on functional recovery after stroke can be evaluated both in humans and rats.
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Affiliation(s)
- A Hodor
- Center for Experimental Neurology (ZEN), Department of Neurology, Inselspital, Bern University Hospital, Switzerland.
| | - S Palchykova
- Center for Experimental Neurology (ZEN), Department of Neurology, Inselspital, Bern University Hospital, Switzerland
| | - B Gao
- Center for Experimental Neurology (ZEN), Department of Neurology, Inselspital, Bern University Hospital, Switzerland
| | - C L Bassetti
- Center for Experimental Neurology (ZEN), Department of Neurology, Inselspital, Bern University Hospital, Switzerland
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Torrens M, Fonseca F. Role of ALDH5A1 in methadone treatment. Pharmacogenomics 2014; 15:573-6. [PMID: 24798712 DOI: 10.2217/pgs.14.13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Affiliation(s)
- Marta Torrens
- Institut de Neuropsiquiatria i Addicions, Hospital del Mar, Institut Hospital del Mar d'Investigacions Mèdiques (IMIM), Barcelona, Spain and Psychiatry Department, Universitat Autònoma de Barcelona, Barcelona, Spain
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Fonseca F, Gratacòs M, Escaramís G, De Cid R, Martín-Santos R, Farré M, Estivill X, Torrens M. ALDH5A1 variability in opioid dependent patients could influence response to methadone treatment. Eur Neuropsychopharmacol 2014; 24:420-4. [PMID: 24230997 DOI: 10.1016/j.euroneuro.2013.10.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Revised: 09/04/2013] [Accepted: 10/09/2013] [Indexed: 11/17/2022]
Abstract
Methadone maintenance treatment is the most widely-used therapy in opioid dependence, but some patients relapse or drop out from treatment. We genotyped a genetic variant in the succinic semialdehyde dehydrogenase enzyme gene, ALDH5A1, and found that subjects carrying the T variant allele have a higher risk to be nonresponders to methadone treatment (OR=3.16; 95% CI [1.48-6.73], P=0.0024). This could be due to a reduction in the ALDH5A1 enzyme activity, that would increase endogenous gamma-hydroxbutyric acid (GHB) and gamma-aminobutyric acid (GABA) levels and therefore, inducing symptoms such as sedation and impaired pschomotor performance. These neuropsychological effects related with the reduction in enzyme activity could be responsible for a higher propensity to relapse in these genetically predisposed patients.
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Affiliation(s)
- Francina Fonseca
- Institut de Neuropsiquiatria i Addicions, Hospital del Mar, Barcelona, Spain; Institut Hospital del Mar d'Investigacions Mèdiques (IMIM), Barcelona, Spain
| | - Mònica Gratacòs
- CIBER Epidemiología y Salud Pública (CIBERESP) and Genes and Disease Program, Barcelona, Spain
| | - Geòrgia Escaramís
- CIBER Epidemiología y Salud Pública (CIBERESP) and Genes and Disease Program, Barcelona, Spain
| | - Rafael De Cid
- CIBER Epidemiología y Salud Pública (CIBERESP) and Genes and Disease Program, Barcelona, Spain; Center for Genomic Regulation (CRG-UPF), Parc de Recerca Biomèdica (PRBB), Barcelona, Spain
| | - Rocío Martín-Santos
- Institut Hospital del Mar d'Investigacions Mèdiques (IMIM), Barcelona, Spain; Service of Psychiatry and Psychology, Neuroscience Institute, Hospital Clinic, Institut d'Investigació Biomèdiques August Pi i Sunyer (IDIBAPS), Centro de Investigación Biomédica en Red en Salud Mental (CIBERSAM), Barcelona, Spain; Department of Psychiatry and Clinical Psychobiology, University of Barcelona, Barcelona, Spain
| | - Magi Farré
- Institut Hospital del Mar d'Investigacions Mèdiques (IMIM), Barcelona, Spain; Psychiatry and Pharmacology Departments, Autonomous University of Barcelona, Barcelona, Spain
| | - Xavier Estivill
- CIBER Epidemiología y Salud Pública (CIBERESP) and Genes and Disease Program, Barcelona, Spain; Center for Genomic Regulation (CRG-UPF), Parc de Recerca Biomèdica (PRBB), Barcelona, Spain; Experimental and Health Sciences Department, Pompeu Fabra University, Barcelona, Spain
| | - Marta Torrens
- Institut de Neuropsiquiatria i Addicions, Hospital del Mar, Barcelona, Spain; Institut Hospital del Mar d'Investigacions Mèdiques (IMIM), Barcelona, Spain; Psychiatry and Pharmacology Departments, Autonomous University of Barcelona, Barcelona, Spain.
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Abstract
For six decades, the principal mode of action of antidepressant drugs is the inhibition of monoamine re-uptake from the synaptic cleft. Tricyclic antidepressants, selective serotonin re-uptake inhibitors (SSRIs) and the new generation of dual antidepressants all exert their antidepressant effects by this mechanism. In the early days of the monoaminergic era, other efforts have been made to ameliorate the symptoms of depression by pharmacological means. The gamma-aminobutyric acid (GABA) system was and possibly still is one of the main alternative drug targets. Gammahydroxybutyrate (GHB) was developed as an orally active GABA analogue. It was tested in animal models of depression and human studies. The effects on sleep, agitation, anhedonia and depression were promising. However, the rise of benzodiazepines and tricyclic antidepressants brought GHB out of the scope of possible treatment alternatives. GHB is a GABA(B) and GHB receptor agonist with a unique spectrum of behavioural, neuroendocrine and sleep effects, and improves daytime sleepiness in various disorders such as narcolepsy, Parkinson's disease and fibromyalgia. Although it was banned from the US market at the end of the 1990s because of its abuse and overdose potential, it later was approved for the treatment of narcolepsy. New research methods and an extended view on other neurotransmitter systems as possible treatment targets of antidepressant treatment brought GHB back to the scene. This article discusses the unique neurobiological effects of GHB, its misuse potential and possible role as a model substance for the development of novel pharmacological treatment strategies in depressive disorders.
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Affiliation(s)
- Oliver G Bosch
- Clinic of Affective Disorders and General Psychiatry, University Hospital of Psychiatry, University of Zurich, Zurich, Switzerland.
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Abstract
Fibromyalgia syndrome (FMS) is a common disorder, characterized by diffuse pain and tenderness, stiffness, fatigue, affective disorders and significant sleep pathology. A new set of diagnostic criteria have been developed which should make it easier for a busy clinician to diagnose the condition. US Food and Drug Administration (FDA) approved medications for the treatment of FMS have, for the most part, been geared to modulate the pain pathways to give the patient some degree of relief. A different kind of pharmacological agent, sodium oxybate (SXB), is described that is currently approved for the treatment of excessive daytime sleepiness and cataplexy in patients with narcolepsy. SXB, an endogenous metabolite of the inhibitory neurotransmitter gamma-hydroxybutyrate, is thought to act independently as a neurotransmitter with a presumed ability to modulate numerous other central nervous system neurotransmitters. In addition SXB has been shown to robustly increase slow wave sleep and decrease sleep fragmentation. Several large clinical trials have demonstrated SXB's ability to statistically improve pain, fatigue and a wide array of quality of life measurements of patients with fibromyalgia. SXB is not FDA approved to treat fibromyalgia.
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Affiliation(s)
- Todd J. Swick
- The Houston Sleep Center, 7500 San Felipe, Houston, TX 77063, USA.
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21
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Abstract
INTRODUCTION Gamma-hydroxybutyrate (GHB) is a short-chain fatty acid that is synthesized within the CNS, mostly from its parent compound gamma amino butyric acid (GABA). GHB acts as a neuromodulator/neurotransmitter to affect neuronal activity of other neurotransmitters and so, stimulate the release of growth hormone. Its sodium salt (sodium oxybate: SXB) was approved by the Food and Drug Administration (FDA) for the treatment of narcolepsy. SXB has shown to improve disrupted sleep and increase NR3 (slow-wave restorative) sleep in patients with narcolepsy. It is rapidly absorbed and has a plasma half-life of 30 - 60 min, necessitating twice-nightly dosing. Most of the observed effects of SXB result from binding to GABA-B receptors. AREAS COVERED Several randomized, controlled trials demonstrated significantly improved fibromyalgia (FM) symptoms with SXB. As seen in narcolepsy trials, SXB improved sleep of FM patients, increased slow-wave sleep duration as well as delta power, and reduced frequent night-time awakenings. Furthermore, FM pain and fatigue was consistently reduced with nightly SXB over time. Commonly reported adverse events included headache, nausea, dizziness and somnolence. Despite its proven efficacy, SXB did not receive FDA approval for the management of FM in 2010, mostly because of concerns about abuse. EXPERT OPINION Insomnia, fatigue and pain are important clinical FM symptoms that showed moderate improvements with SXB in several large, well-designed clinical trials. Because of the limited efficacy of currently available FM drugs additional treatment options are needed. In particular, drugs like SXB - which belong to a different drug class than other Food and Drug Administration (FDA)-approved FM medications such as pregabalin, duloxetine and milnacipran - would provide a much-needed addition to presently available treatment options. However, the FDA has set the bar high for future SXB re-submissions, with requirements of superior efficacy and improved risk mitigation strategies. At this time, no future FDA submission of SXB for the fibromyalgia indication is planned.
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Affiliation(s)
- Roland Staud
- University of Florida-Medicine, 1600 SW Archer Rd, Gainesville, FL 32610-0221, USA.
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Abstract
Excessive daytime sleepiness (EDS) is described as inappropriate and undesirable sleepiness during waking hours and is a common non-motor symptom in Parkinson's disease, affecting up to 50% of patients. EDS has a large impact on the quality of life of Parkinson's disease patients as well as of their caregivers, in some cases even more than the motor symptoms of the disease. Drug-induced EDS is a particular problem as many dopamine agonists used for the treatment of Parkinson's disease have EDS as an adverse effect. Dopaminergic treatment may also render a subset of Parkinson's disease patients at risk for sudden-onset sleep attacks that occur without warning and can be particularly hazardous if the patient is driving. This demonstrates the need for early recognition and management not only to increase health-related quality of life but also to ensure patient safety. There are many assessment tools for EDS, including the Epworth Sleepiness Scale (ESS) and the Multiple Sleep Latency Test (MSLT), although only the Parkinson's Disease Sleep Scale (PDSS) and the SCales for Outcomes in PArkinson's Disease-Sleep (SCOPA-S) are specifically validated for Parkinson's disease. Polysomnography can be used when necessary. Management comprises non-pharmacological and pharmacological approaches. Non-pharmacological approaches can be the mainstay of treatment for mild to moderate EDS. Advice on good sleep hygiene is instrumental, as pharmacological approaches have yet to provide consistent and reliable results without significant adverse effects. The efficacy of pharmacological treatment of EDS in Parkinson's disease using wakefulness-promoting drugs such as modafinil remains controversial. Further areas of research are now also focusing on adenosine A(2A) receptor antagonists, sodium oxybate and caffeine to promote wakefulness. A definitive treatment for the highly prevalent drug-induced EDS has not yet been found.
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Affiliation(s)
- Bettina Knie
- Charit Universitätsmedizin Berlin, Berlin, Germany
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Abstract
Despite the therapeutic use and abuse potential of gamma-hydroxybutyrate (GHB or Xyrem), relatively few studies have examined the behavioral effects of GHB in humans under controlled laboratory conditions. Thus, this eight-session study examined in 10 non-substance-abusing volunteers the behavioral effects of GHB at each of the following doses: 0, 0.32, 0.56, 0.75, 1.0, 1.8, 2.4, 3.2 g/70 kg, orally. Order of dose testing was random, except that the first two participants received active doses in ascending order and 2.4 g/70 kg was always tested before 3.2 g/70 kg. Before drug administration and at several postdrug time points, self-report, observer report, physiological, and psychomotor performance measures were obtained. Analyses based on area under the curve showed that GHB produced dose-related increases in subjective ratings of sedative-like, stimulant-like, positive mood, and dissociative effects, but no changes in psychomotor performance measures or blood pressure. Analyses based on peak effects generally showed dose-related increases in ratings indicating sedative-like, dissociative, and drug liking, although some measures showed U-shaped dose-related changes. These initial findings suggest that GHB at doses of 0.32-3.2 g/70 kg produces dissociative, sedating and some stimulant-like effects in humans without a history of sedative abuse.
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Affiliation(s)
- Alison Oliveto
- Department of Psychiatry and Behavioral Sciences,University of Arkansas for Medical Sciences, 4301 W. Markham St., Little Rock, AR 72205, USA.
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Bambico FR, Nguyen NT, Katz N, Gobbi G. Chronic exposure to cannabinoids during adolescence but not during adulthood impairs emotional behaviour and monoaminergic neurotransmission. Neurobiol Dis 2009; 37:641-55. [PMID: 19969082 DOI: 10.1016/j.nbd.2009.11.020] [Citation(s) in RCA: 118] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2009] [Revised: 11/21/2009] [Accepted: 11/26/2009] [Indexed: 12/27/2022] Open
Abstract
The pathophysiological neural mechanism underlying the depressogenic and anxiogenic effects of chronic adolescent cannabinoid use may be linked to perturbations in monoaminergic neurotransmission. We tested this hypothesis by administering the CB(1) receptor agonist WIN55,212-2, once daily for 20 days to adolescent and adult rats, subsequently subjecting them to tests for emotional reactivity paralleled by the in vivo extracellular recordings of serotonergic and noradrenergic neurons. Chronic adolescent exposure but not adult exposure to low (0.2 mg/kg) and high (1.0 mg/kg) doses led to depression-like behaviour in the forced swim and sucrose preference test, while the high dose also induced anxiety-like consequences in the novelty-suppressed feeding test. Electrophysiological recordings revealed both doses to have attenuated serotonergic activity, while the high dose also led to a hyperactivity of noradrenergic neurons only after adolescent exposure. These suggest that long-term exposure to cannabinoids during adolescence induces anxiety-like and depression-like behaviours in adulthood and that this may be instigated by serotonergic hypoactivity and noradrenergic hyperactivity.
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Affiliation(s)
- Francis Rodriguez Bambico
- Neurobiological Psychiatry Unit, Department of Psychiatry, McGill University, 1033 Pine Avenue West, Montreal, Canada H3A1A1
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Mamelak M. Narcolepsy and depression and the neurobiology of gammahydroxybutyrate. Prog Neurobiol 2009; 89:193-219. [PMID: 19654034 DOI: 10.1016/j.pneurobio.2009.07.004] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2009] [Revised: 05/24/2009] [Accepted: 07/28/2009] [Indexed: 12/23/2022]
Abstract
A voluminous literature describes the relationship between disturbed sleep and depression. The breakdown of sleep is one of the cardinal features of depression and often also heralds its onset. Frequent arousals, periods of wakefulness and a short sleep onset REM latency are typical polysomnographic features of depression. The short latency to REM sleep has been attributed to the combination of a monoaminergic deficiency and cholinergic supersensitivity and these irregularities have been proposed to form the biological basis of the disorder. A similar imbalance between monoaminergic and cholinergic neurotransmission has been found in narcolepsy, a condition in which frequent awakenings, periods of wakefulness and short sleep onset REM latencies are also characteristic findings during sleep. In many cases of narcolepsy, this imbalance appears to result from a deficiency of hypocretin but once established, whether in depression or narcolepsy, this disequilibrium sets the stage for the dissociation or premature appearance of REM sleep and for the dissociation of the motor inhibitory component of REM sleep or cataplexy. In the presence of this monoaminergic/cholinergic imbalance, gammahydroxybutyrate (GHB) may acutely further reduce the latency of REM sleep and induce cataplexy, in both patients with narcolepsy or depression. On the other hand, the repeated nocturnal application of GHB in patients with narcolepsy improves the continuity of sleep, prolongs the latency to REM sleep and prevents cataplexy. Evidence to date suggests that GHB may restore the normal balance between monoaminergic and cholinergic neurotransmission. As such, the repeated use of GHB at night and the stabilization of sleep over time makes GHB an effective treatment for narcolepsy and a potentially effective treatment for depression.
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Affiliation(s)
- Mortimer Mamelak
- Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada.
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26
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Abstract
BACKGROUND Narcolepsy is a rare chronic sleep disorder classically characterized by excessive daytime sleepiness. Other symptoms of the disease, including cataplexy, sleep paralysis, hypnagogic hallucinations and disturbed nocturnal sleep, may follow later. The disease can be incapacitating and frequently results in impaired psychosocial interaction. In the absence of a cure for narcolepsy, medical therapy is directed at symptom control. OBJECTIVES The aim of this study was to review the current approach to the treatment of narcolepsy. METHODS A search of three bibliographic databases (MEDLINE/PubMed, EMBASE and the Cochrane Library Database) was conducted from 1966 to January 2008 using the National Library of Medicine MeSH search terms narcolepsy and cataplexy. Relevant studies, case reports, review articles, editorials, short communications and chapters from selected textbooks were then extracted and manually cross-referenced. RESULTS/CONCLUSIONS Traditionally, stimulants have been used to improve the symptoms of excessive daytime sleepiness. However, the treatment of narcolepsy has evolved recently with the widespread use of newer drugs, including modafinil for daytime sleepiness, newer antidepressants for cataplexy and gamma-hydroxybutyrate (sodium oxybate) for both excessive daytime sleepiness and cataplexy.
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Affiliation(s)
- Abid Bhat
- Hospital Hill, Division of Pulmonary and Critical Care Medicine, Department of Medicine, Truman Medical Center, Kansas City, MO, USA
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27
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Abstract
Sodium oxybate (Xyrem) is the sodium salt of the CNS depressant gamma-hydroxybutyric acid (GHB) and is therefore subject to prescription restrictions. It is approved in the US for the treatment of cataplexy and excessive daytime sleepiness (EDS) in patients with narcolepsy, and in the EU for the treatment of narcolepsy with cataplexy. Sodium oxybate is generally well tolerated and effective in the treatment of symptoms of narcolepsy with cataplexy. While its short half-life necessitates twice-nightly administration, it is highly effective in reducing the frequency of cataplexy, improving sleep architecture and reducing EDS in patients with narcolepsy. Sodium oxybate therefore offers a valuable alternative or addition to the use of TCAs, SSRIs and stimulants in the treatment of the symptoms of narcolepsy including cataplexy and EDS.
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28
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Abstract
Sodium oxybate is the sodium salt of γ-hydroxybutyrate (GHB), an endogenous short-chain fatty acid that is speculated to function as a neurotransmitter in the mammalian CNS. Pharmacodynamic effects of exogenously-administered sodium oxybate may include modulating the release of neurotransmitters, including γ-aminobutyric acid, dopamine, endogenous opioids and serotonin, and stimulating release of growth hormone. It is rapidly absorbed, with approximately 25% bioavailability and a plasma half-life of 40–60 min, necessitating twice-nightly dosing. Sodium oxybate is indicated for the treatment of cataplexy and excessive daytime sleepiness in patients with narcolepsy, and has been shown to improve disrupted night-time sleep and increase Stage 3 and 4 (slow-wave restorative) sleep in this patient population. The most common adverse events reported in clinical trials in patients with narcolepsy include headache, nausea, dizziness, nasopharyngitis, somnolence, vomiting and urinary incontinence.
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Affiliation(s)
- Daniel Pardi
- Jazz Pharmaceuticals, Inc., Medical Affairs Department, 3180 Porter Drive, Palo Alto, CA 94304, USA
| | - Jed E Black
- Stanford University, Stanford Sleep Disorders Clinic, 401 Quarry Road, Suite 3301, Stanford, CA 94305, USA
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Affiliation(s)
- O Carter Snead
- Department of Pediatrics, University of Toronto, and the Division of Neurology and the Brain and Behavior Research Program, Hospital for Sick Children, Toronto, ON, Canada
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