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Lorenz-Guertin JM, Povysheva N, Chapman CA, MacDonald ML, Fazzari M, Nigam A, Nuwer JL, Das S, Brady ML, Vajn K, Bambino MJ, Weintraub ST, Johnson JW, Jacob TC. Inhibitory and excitatory synaptic neuroadaptations in the diazepam tolerant brain. Neurobiol Dis 2023; 185:106248. [PMID: 37536384 PMCID: PMC10578451 DOI: 10.1016/j.nbd.2023.106248] [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: 05/12/2023] [Revised: 07/20/2023] [Accepted: 07/31/2023] [Indexed: 08/05/2023] Open
Abstract
Benzodiazepine (BZ) drugs treat seizures, anxiety, insomnia, and alcohol withdrawal by potentiating γ2 subunit containing GABA type A receptors (GABAARs). BZ clinical use is hampered by tolerance and withdrawal symptoms including heightened seizure susceptibility, panic, and sleep disturbances. Here, we investigated inhibitory GABAergic and excitatory glutamatergic plasticity in mice tolerant to benzodiazepine sedation. Repeated diazepam (DZP) treatment diminished sedative effects and decreased DZP potentiation of GABAAR synaptic currents without impacting overall synaptic inhibition. While DZP did not alter γ2-GABAAR subunit composition, there was a redistribution of extrasynaptic GABAARs to synapses, resulting in higher levels of synaptic BZ-insensitive α4-containing GABAARs and a concomitant reduction in tonic inhibition. Conversely, excitatory glutamatergic synaptic transmission was increased, and NMDAR subunits were upregulated at synaptic and total protein levels. Quantitative proteomics further revealed cortex neuroadaptations of key pro-excitatory mediators and synaptic plasticity pathways highlighted by Ca2+/calmodulin-dependent protein kinase II (CAMKII), MAPK, and PKC signaling. Thus, reduced inhibitory GABAergic tone and elevated glutamatergic neurotransmission contribute to disrupted excitation/inhibition balance and reduced BZ therapeutic power with benzodiazepine tolerance.
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Affiliation(s)
- Joshua M Lorenz-Guertin
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Nadya Povysheva
- Department of Neuroscience and Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA
| | - Caitlyn A Chapman
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Matthew L MacDonald
- Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Marco Fazzari
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Aparna Nigam
- Department of Neuroscience and Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA
| | - Jessica L Nuwer
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Sabyasachi Das
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Megan L Brady
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Katarina Vajn
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Matthew J Bambino
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Susan T Weintraub
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, San Antoni, TX, USA
| | - Jon W Johnson
- Department of Neuroscience and Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA
| | - Tija C Jacob
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
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Deng L, Wu L, Gao R, Xu X, Chen C, Liu J. Non-Opioid Anesthetics Addiction: A Review of Current Situation and Mechanism. Brain Sci 2023; 13:1259. [PMID: 37759860 PMCID: PMC10526861 DOI: 10.3390/brainsci13091259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2023] [Revised: 08/15/2023] [Accepted: 08/26/2023] [Indexed: 09/29/2023] Open
Abstract
Drug addiction is one of the major worldwide health problems, which will have serious adverse consequences on human health and significantly burden the social economy and public health. Drug abuse is more common in anesthesiologists than in the general population because of their easier access to controlled substances. Although opioids have been generally considered the most commonly abused drugs among anesthesiologists and nurse anesthetists, the abuse of non-opioid anesthetics has been increasingly severe in recent years. The purpose of this review is to provide an overview of the clinical situation and potential molecular mechanisms of non-opioid anesthetics addiction. This review incorporates the clinical and biomolecular evidence supporting the abuse potential of non-opioid anesthetics and the foreseeable mechanism causing the non-opioid anesthetics addiction phenotypes, promoting a better understanding of its pathogenesis and helping to find effective preventive and curative strategies.
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Affiliation(s)
- Liyun Deng
- Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610041, China; (L.D.); (L.W.); (R.G.); (X.X.); (J.L.)
- The Research Units of West China (2018RU012)-Chinese Academy of Medical Sciences, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Lining Wu
- Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610041, China; (L.D.); (L.W.); (R.G.); (X.X.); (J.L.)
- The Research Units of West China (2018RU012)-Chinese Academy of Medical Sciences, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Rui Gao
- Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610041, China; (L.D.); (L.W.); (R.G.); (X.X.); (J.L.)
- The Research Units of West China (2018RU012)-Chinese Academy of Medical Sciences, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Xiaolin Xu
- Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610041, China; (L.D.); (L.W.); (R.G.); (X.X.); (J.L.)
- The Research Units of West China (2018RU012)-Chinese Academy of Medical Sciences, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Chan Chen
- Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610041, China; (L.D.); (L.W.); (R.G.); (X.X.); (J.L.)
- The Research Units of West China (2018RU012)-Chinese Academy of Medical Sciences, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Jin Liu
- Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610041, China; (L.D.); (L.W.); (R.G.); (X.X.); (J.L.)
- The Research Units of West China (2018RU012)-Chinese Academy of Medical Sciences, West China Hospital, Sichuan University, Chengdu 610041, China
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de Oliveira Moura Araújo E, Gavioli EC, Holanda VAD, da Silva VC, Oliveira Nunes Messias TB, Dutra LMG, de Oliveira MC, Ramos do Egypto Queiroga RDC, Guerra GCB, Soares JKB. REPEATED DONKEY MILK CONSUMPTION REDUCES ANXIETY-LIKE BEHAVIORS AND BRAIN OXIDATIVE DAMAGE TO LIPIDS IN MICE. Behav Brain Res 2023; 449:114477. [PMID: 37150444 DOI: 10.1016/j.bbr.2023.114477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 05/03/2023] [Accepted: 05/03/2023] [Indexed: 05/09/2023]
Abstract
Donkey milk (DM) is a source of bioactive compounds that can benefit neural functioning. In the present study, we investigated the effects of DM consumption on anxiolytic-related, despair-like, locomotion and coordination behaviors, as well as the provision of protection from oxidative damage to lipids and proteins in brain tissues and melatonin plasma levels. To achieve this, male mice orally received DM (4g.kg-1) or vehicle for 18 days. Their behavior was assessed in the following tests: elevated plus maze (EPM), open field and rotarod tests (OF, RR) and forced swimming test (FST). Acute treatments with diazepam (DZP, 1.5mg.kg-1, v.o.), fluoxetine (FLX, 20mg.kg-1, i.p.) and nortriptyline (NTP, 20mg.kg-1, i.p.) were used as positive controls. On the eighteenth day, the animals were euthanized and brain tissue and blood were collected to measure oxidative damage, and melatonin plasma levels. Similar to DZP, repeated DM consumption reduced exploration to open areas in the EPM test. Under our experimental conditions, conventional antidepressants reduced immobility time in the FST, and the benzodiazepine treatment impaired motor coordination in mice. No significant differences in locomotion, motor coordination and despair-related behaviors were observed in the mice treated with DM when assessed in the EPM, OF, RR and FST, respectively. Biochemical assays showed that repeated DM exposition protected against oxidative damage to lipids and increased plasma levels of melatonin. These findings suggest consumption of DM may be a promising food for the treatment of anxiety-related disorders, without depressant effects on the central nervous system.
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Affiliation(s)
| | - Elaine Cristina Gavioli
- Department of Biophysics and Pharmacology, Biosciences Centre, Federal University of Rio Grande do Norte, Natal, Brazil
| | | | - Valéria Costa da Silva
- Department of Biophysics and Pharmacology, Biosciences Centre, Federal University of Rio Grande do Norte, Natal, Brazil
| | | | | | - Matheus Cardoso de Oliveira
- Department of Biophysics and Pharmacology, Biosciences Centre, Federal University of Rio Grande do Norte, Natal, Brazil
| | | | | | - Juliana Kessia Barbosa Soares
- Department of Food Engineering, Technology Centre, Federal University of Paraíba, Brazil; Center of Education and Health, Federal University of Campina Grande, Cuité, Brazil
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Warlick H, Leon L, Patel R, Filoramo S, Knipe R, Joubran E, Levy A, Nguyen H, Rey J. Application of gabapentinoids and novel compounds for the treatment of benzodiazepine dependence: the glutamatergic model. Mol Biol Rep 2023; 50:1765-1784. [PMID: 36456769 DOI: 10.1007/s11033-022-08110-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Accepted: 11/09/2022] [Indexed: 12/04/2022]
Abstract
BACKGROUND Current approaches for managing benzodiazepine (BZD) withdrawal symptoms are daunting for clinicians and patients, warranting novel treatment and management strategies. This review discusses the pharmacodynamic properties of BZDs, gabapentinoids (GBPs), endozepines, and novel GABAergic compounds associated with potential clinical benefits for BZD-dependent patients. The objective of this study was to review the complex neuromolecular changes occurring within the GABAergic and glutamatergic systems during the BZD tolerance and withdrawal periods while also examining the mechanism by which GBPs and alternative pharmacological therapies may attenuate withdrawal symptoms. METHODS AND RESULTS An elaborative literature review was conducted using multiple platforms, including the National Center for Biotechnology (NCBI), AccessMedicine, ScienceDirect, pharmacology textbooks, clinical trial data, case reports, and PubChem. Our literature analysis revealed that many distinctive neuroadaptive mechanisms are involved in the GABAergic and glutamatergic systems during BZD tolerance and withdrawal. Based on this data, we hypothesize that GBPs may attenuate the overactive glutamatergic system during the withdrawal phase by an indirect presynaptic glutamatergic mechanism dependent on the α2δ1 subunit expression. CONCLUSIONS GBPs may benefit individuals undergoing BZD withdrawal, given that the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor current significantly increases during abrupt BZD withdrawal in animal studies. This may be a conceivable explanation for the effectiveness of GBPs in treating both alcohol withdrawal symptoms and BZD withdrawal symptoms in some recent studies. Finally, natural and synthetic GABAergic compounds with unique pharmacodynamic properties were found to exert potential clinical benefits as BZD substitutes in animal studies, though human studies are lacking.
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Affiliation(s)
- Halford Warlick
- Dr. Kiran C. Patel College Of Osteopathic Medicine, Nova Southeastern University, Davie, FL, USA.
| | - Lexie Leon
- Dr. Kiran C. Patel College Of Osteopathic Medicine, Nova Southeastern University, Davie, FL, USA
| | - Rudresh Patel
- Dr. Kiran C. Patel College Of Osteopathic Medicine, Nova Southeastern University, Davie, FL, USA
| | - Stefanie Filoramo
- Dr. Kiran C. Patel College Of Osteopathic Medicine, Nova Southeastern University, Davie, FL, USA
| | - Ryan Knipe
- Dr. Kiran C. Patel College Of Osteopathic Medicine, Nova Southeastern University, Davie, FL, USA
| | - Ernesto Joubran
- Dr. Kiran C. Patel College Of Osteopathic Medicine, Nova Southeastern University, Davie, FL, USA
| | - Arkene Levy
- Dr. Kiran C. Patel College of Allopathic Medicine, Nova Southeastern University, Davie, FL, USA
| | - Hoang Nguyen
- Dr. Kiran C. Patel College Of Osteopathic Medicine, Nova Southeastern University, Davie, FL, USA
| | - Jose Rey
- College of Pharmacy, Nova Southeastern University, Davie, FL, USA
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Ali AB, Islam A, Constanti A. The fate of interneurons, GABA A receptor sub-types and perineuronal nets in Alzheimer's disease. Brain Pathol 2022; 33:e13129. [PMID: 36409151 PMCID: PMC9836378 DOI: 10.1111/bpa.13129] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 10/12/2022] [Indexed: 11/23/2022] Open
Abstract
Alzheimer's disease (AD) is the most common neurological disease, which is associated with gradual memory loss and correlated with synaptic hyperactivity and abnormal oscillatory rhythmic brain activity that precedes phenotypic alterations and is partly responsible for the spread of the disease pathology. Synaptic hyperactivity is thought to be because of alteration in the homeostasis of phasic and tonic synaptic inhibition, which is orchestrated by the GABAA inhibitory system, encompassing subclasses of interneurons and GABAA receptors, which play a vital role in cognitive functions, including learning and memory. Furthermore, the extracellular matrix, the perineuronal nets (PNNs) which often go unnoticed in considerations of AD pathology, encapsulate the inhibitory cells and neurites in critical brain regions and have recently come under the light for their crucial role in synaptic stabilisation and excitatory-inhibitory balance and when disrupted, serve as a potential trigger for AD-associated synaptic imbalance. Therefore, in this review, we summarise the current understanding of the selective vulnerability of distinct interneuron subtypes, their synaptic and extrasynaptic GABAA R subtypes as well as the changes in PNNs in AD, detailing their contribution to the mechanisms of disease development. We aim to highlight how seemingly unique malfunction in each component of the interneuronal GABA inhibitory system can be tied together to result in critical circuit dysfunction, leading to the irreversible symptomatic damage observed in AD.
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Engin E. GABA A receptor subtypes and benzodiazepine use, misuse, and abuse. Front Psychiatry 2022; 13:1060949. [PMID: 36713896 PMCID: PMC9879605 DOI: 10.3389/fpsyt.2022.1060949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Accepted: 12/29/2022] [Indexed: 01/14/2023] Open
Abstract
Benzodiazepines have been in use for over half a century. While they remain highly prescribed, their unfavorable side-effect profile and abuse liability motivated a search for alternatives. Most of these efforts focused on the development of benzodiazepine-like drugs that are selective for specific GABAA receptor subtypes. While there is ample evidence that subtype-selective GABAA receptor ligands have great potential for providing symptom relief without typical benzodiazepine side-effects, it is less clear whether subtype-selective targeting strategies can also reduce misuse and abuse potential. This review focuses on the three benzodiazepine properties that are relevant to the DSM-5-TR criteria for Sedative, Hypnotic, or Anxiolytic Use Disorder, namely, reinforcing properties of benzodiazepines, maladaptive behaviors related to benzodiazepine use, and benzodiazepine tolerance and dependence. We review existing evidence regarding the involvement of different GABAA receptor subtypes in each of these areas. The reviewed studies suggest that α1-containing GABAA receptors play an integral role in benzodiazepine-induced plasticity in reward-related brain areas and might be involved in the development of tolerance and dependence to benzodiazepines. However, a systematic comparison of the contributions of all benzodiazepine-sensitive GABAA receptors to these processes, a mechanistic understanding of how the positive modulation of each receptor subtype might contribute to the brain mechanisms underlying each of these processes, and a definitive answer to the question of whether specific chronic modulation of any given subtype would result in some or all of the benzodiazepine effects are currently lacking from the literature. Moreover, how non-selective benzodiazepines might lead to the maladaptive behaviors listed in DSM and how different GABAA receptor subtypes might be involved in the development of these behaviors remains unexplored. Considering the increasing burden of benzodiazepine abuse, the common practice of benzodiazepine misuse that leads to severe dependence, and the current efforts to generate side-effect free benzodiazepine alternatives, there is an urgent need for systematic, mechanistic research that provides a better understanding of the brain mechanisms of benzodiazepine misuse and abuse, including the involvement of specific GABAA receptor subtypes in these processes, to establish an informed foundation for preclinical and clinical efforts.
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Affiliation(s)
- Elif Engin
- Stress Neurobiology Laboratory, Division of Basic Neuroscience, McLean Hospital, Belmont, MA, United States.,Department of Psychiatry, Harvard Medical School, Boston, MA, United States
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Tolerance and dependence following chronic alprazolam treatment in rhesus monkeys: Role of GABA A receptor subtypes. Drug Alcohol Depend 2021; 228:108985. [PMID: 34500240 PMCID: PMC8595788 DOI: 10.1016/j.drugalcdep.2021.108985] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 07/24/2021] [Accepted: 07/26/2021] [Indexed: 11/23/2022]
Abstract
BACKGROUND To assess GABAA receptor subtypes involved in benzodiazepine tolerance and dependence, we evaluated the ability of subtype-selective and non-selective ligands to substitute for (i.e., produce "cross-tolerance") or precipitate withdrawal during chronic alprazolam treatment. METHODS Four female rhesus monkeys (Macaca mulatta) were implanted with chronic intravenous catheters and administered alprazolam (1.0 mg/kg every 4 h). Following 14+ days of chronic alprazolam, acute administration of selected doses of non-selective and subtype-selective ligands were substituted for, or administered with, alprazolam, followed by quantitative behavioral observations. The ligands included alprazolam and midazolam (positive modulators, non-selective), zolpidem (positive modulator, preferential affinity for α1-containing GABAA receptors), HZ-166 (positive modulator, preferential efficacy at α2- and α3-containing GABAA receptors), and βCCT (antagonist, preferential affinity for α1-containing GABAA receptors). RESULTS Acutely, alprazolam and midazolam both induced observable ataxia along with a mild form of sedation referred to as "rest/sleep posture" at a lower dose (0.1 mg/kg, i.v.), whereas at a higher dose (1.0 mg/kg, i.v.), induced deep sedation and observable ataxia. With chronic alprazolam treatment, observable ataxia and deep sedation were reduced significantly, whereas rest/sleep posture was unchanged or emerged. Zolpidem showed a similar pattern of effects, whereas no behaviors engendered by HZ-166 were changed by chronic alprazolam. Administration of βCCT, but not HZ-166, resulted in significant withdrawal signs. CONCLUSIONS These results are consistent with a role for α1-containing GABAA receptor subtypes in tolerance and dependence observed with chronic alprazolam, although other receptors may be involved in the withdrawal syndrome.
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Belelli D, Hales TG, Lambert JJ, Luscher B, Olsen R, Peters JA, Rudolph U, Sieghart W. GABA A receptors in GtoPdb v.2021.3. IUPHAR/BPS GUIDE TO PHARMACOLOGY CITE 2021; 2021. [PMID: 35005623 DOI: 10.2218/gtopdb/f72/2021.3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The GABAA receptor is a ligand-gated ion channel of the Cys-loop family that includes the nicotinic acetylcholine, 5-HT3 and strychnine-sensitive glycine receptors. GABAA receptor-mediated inhibition within the CNS occurs by fast synaptic transmission, sustained tonic inhibition and temporally intermediate events that have been termed 'GABAA, slow' [45]. GABAA receptors exist as pentamers of 4TM subunits that form an intrinsic anion selective channel. Sequences of six α, three β, three γ, one δ, three ρ, one ε, one π and one θ GABAA receptor subunits have been reported in mammals [278, 235, 236, 283]. The π-subunit is restricted to reproductive tissue. Alternatively spliced versions of many subunits exist (e.g. α4- and α6- (both not functional) α5-, β2-, β3- and γ2), along with RNA editing of the α3 subunit [71]. The three ρ-subunits, (ρ1-3) function as either homo- or hetero-oligomeric assemblies [359, 50]. Receptors formed from ρ-subunits, because of their distinctive pharmacology that includes insensitivity to bicuculline, benzodiazepines and barbiturates, have sometimes been termed GABAC receptors [359], but they are classified as GABA A receptors by NC-IUPHAR on the basis of structural and functional criteria [16, 235, 236]. Many GABAA receptor subtypes contain α-, β- and γ-subunits with the likely stoichiometry 2α.2β.1γ [168, 235]. It is thought that the majority of GABAA receptors harbour a single type of α- and β - subunit variant. The α1β2γ2 hetero-oligomer constitutes the largest population of GABAA receptors in the CNS, followed by the α2β3γ2 and α3β3γ2 isoforms. Receptors that incorporate the α4- α5-or α 6-subunit, or the β1-, γ1-, γ3-, δ-, ε- and θ-subunits, are less numerous, but they may nonetheless serve important functions. For example, extrasynaptically located receptors that contain α6- and δ-subunits in cerebellar granule cells, or an α4- and δ-subunit in dentate gyrus granule cells and thalamic neurones, mediate a tonic current that is important for neuronal excitability in response to ambient concentrations of GABA [209, 272, 83, 19, 288]. GABA binding occurs at the β+/α- subunit interface and the homologous γ+/α- subunits interface creates the benzodiazepine site. A second site for benzodiazepine binding has recently been postulated to occur at the α+/β- interface ([254]; reviewed by [282]). The particular α-and γ-subunit isoforms exhibit marked effects on recognition and/or efficacy at the benzodiazepine site. Thus, receptors incorporating either α4- or α6-subunits are not recognised by 'classical' benzodiazepines, such as flunitrazepam (but see [356]). The trafficking, cell surface expression, internalisation and function of GABAA receptors and their subunits are discussed in detail in several recent reviews [52, 140, 188, 316] but one point worthy of note is that receptors incorporating the γ2 subunit (except when associated with α5) cluster at the postsynaptic membrane (but may distribute dynamically between synaptic and extrasynaptic locations), whereas as those incorporating the δ subunit appear to be exclusively extrasynaptic. NC-IUPHAR [16, 235, 3, 2] class the GABAA receptors according to their subunit structure, pharmacology and receptor function. Currently, eleven native GABAA receptors are classed as conclusively identified (i.e., α1β2γ2, α1βγ2, α3βγ2, α4βγ2, α4β2δ, α4β3δ, α5βγ2, α6βγ2, α6β2δ, α6β3δ and ρ) with further receptor isoforms occurring with high probability, or only tentatively [235, 236]. It is beyond the scope of this Guide to discuss the pharmacology of individual GABAA receptor isoforms in detail; such information can be gleaned in the reviews [16, 95, 168, 173, 143, 278, 216, 235, 236] and [9, 10]. Agents that discriminate between α-subunit isoforms are noted in the table and additional agents that demonstrate selectivity between receptor isoforms, for example via β-subunit selectivity, are indicated in the text below. The distinctive agonist and antagonist pharmacology of ρ receptors is summarised in the table and additional aspects are reviewed in [359, 50, 145, 223]. Several high-resolution cryo-electron microscopy structures have been described in which the full-length human α1β3γ2L GABAA receptor in lipid nanodiscs is bound to the channel-blocker picrotoxin, the competitive antagonist bicuculline, the agonist GABA (γ-aminobutyric acid), and the classical benzodiazepines alprazolam and diazepam [198].
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9
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Manna SSS. Possible influence of neurosteroids in the anxiolytic effects of alpha-casozepine. Med Hypotheses 2021; 155:110655. [PMID: 34392107 DOI: 10.1016/j.mehy.2021.110655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Revised: 06/08/2021] [Accepted: 07/28/2021] [Indexed: 11/29/2022]
Abstract
Alpha-casozepine (α CZP), a tryptic hydrolysate of milk casein is a decapeptide shown to promote sleep and produce anxiolytic or anticonvulsant activity. Intriguingly, studies indicate structural similarities to benzodiazepine (BZD)-like molecules (e.g., diazepam), resulting in positive modulation of γ-aminobutyric acid A type (GABAA) receptors. However, some unexplained anomalous behaviour of α-CZP includes 1) 1000 times less affinity for BZD site on GABAA receptor in vitro conditions, whereas in vivo it showed 10-fold increased affinity when compared to diazepam; 2) anxiolytic effects were observed only in stressed conditions and 3) unlike diazepam, it failed to exhibit dependence or habituation. Interestingly, neurosteroids like allopregnanolone or its analogues that are synthesized de novo have both genomic and non-genomic actions. The rapid nongenomic neuronal inhibition of these compounds is mediated by GABAA receptors through autocrine and paracrine actions. Studies have shown that changes in the levels of neurosteroids during acute (rise) and chronic stress (decreased), consequently, altering the senetivity of GABAA receptor subunits. Neurosteroids even at low concentration (nanomolar range) potentiate the response of GABA indirectly, while at higher concentrations they directly activate the receptor-channel complex. Interestingly, coadministration of neurosteroids and BZPs has shown not only to prevent the development of tolerance of BZP and augmented recovery from BZP withdrawal anxiety and hyperactivity in mice. The combination also produced synergetic anxiolytic effects. Taken together, the evidence suggests possible implications of neurosteroids in the actions of CZP via BZD receptors. The present hypothesis brings out the possible role of neurosteroids and the various factors that might participate in CZP-induce anxiolytic effects.
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Affiliation(s)
- Shyamshree S S Manna
- Dr. B. C. Roy College of Pharmacy Allied Health Sciences, Dr Meghnad Saha Sarani, Bidhannagar, Durgapur 713206, West Bengal, India.
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10
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Lewter LA, Golani LK, Cook JM, Li JX. Blockade of α1 subtype GABAA receptors attenuates the development of tolerance to the antinociceptive effects of midazolam in rats. Behav Pharmacol 2021; 32:345-350. [PMID: 33290344 PMCID: PMC8119291 DOI: 10.1097/fbp.0000000000000614] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Benzodiazepines bind to and act on α1-3 and α5-containing GABAA receptors. Previous studies suggest that different GABAA receptor α-subtypes mediate the various behavioral effects of benzodiazepines, which raises the possibility of combining benzodiazepines with subtype-selective GABAA receptor antagonists to improve the therapeutic profiles of benzodiazepines. This study examined the GABAA receptor subtype mediation of the tolerance to midazolam-induced antinociception in rats. Midazolam (3.2 mg/kg) significantly reduced the locomotion in rats which was prevented by the selective α1-preferring GABAA receptor antagonist β-carboline-3-carboxylate-t-butyl ester (βCCt) (3.2 mg/kg). Midazolam increased the paw withdrawal threshold as tested by the von Frey filament assay in the complete Freund's adjuvant-induced inflammatory pain model in rats, and this effect was not altered by βCCt or another α1-preferring GABAA receptor antagonist 3-propoxy-β-carboline hydrochloride (3PBC). Repeated treatment with midazolam in combination with vehicle, βCCt or 3PBC (twice daily) for 7 days led to a progressive increase of the ED50 values in the midazolam- and vehicle-treated rats, but not in other rats, suggesting the development of tolerance to midazolam but not to the combination of midazolam with α1-preferring GABAA receptor antagonists. These results suggest the essential role of the α1-subtype of GABAA receptors in mediating the development of tolerance to midazolam-induced antinociceptive effects and raise the possibility of increasing therapeutic profiles of benzodiazepines by selectively blocking specific α-subtypes of GABAA receptors.
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Affiliation(s)
- Lakeisha A. Lewter
- Department of Pharmacology and Toxicology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY
| | - Lalit K Golani
- Department of Chemistry, University of Wisconsin-Milwaukee, Milwaukee, WI
| | - James M. Cook
- Department of Chemistry, University of Wisconsin-Milwaukee, Milwaukee, WI
| | - Jun-Xu Li
- Department of Pharmacology and Toxicology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY
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Biggerstaff A, Kivell B, Smith JL, Mian MY, Golani LK, Rashid F, Sharmin D, Knutson DE, Cerne R, Cook JM, Witkin JM. The α2,3-selective potentiators of GABA A receptors, KRM-II-81 and MP-III-80, produce anxiolytic-like effects and block chemotherapy-induced hyperalgesia in mice without tolerance development. Pharmacol Biochem Behav 2020; 196:172996. [PMID: 32668266 DOI: 10.1016/j.pbb.2020.172996] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 07/03/2020] [Accepted: 07/07/2020] [Indexed: 12/13/2022]
Abstract
Opiate analgesics are one of the treatment options for severe chronic pain, including late-stage cancer, chronic back pain and other disorders. The recent resurgence in opioid overdose has highlighted the serious need for alternative medicines for pain management. While a role for potentiators of α2/3-containing GABAA receptors in the modulation of pain has been known for several years, advancements in this area required data from selective compounds. KRM-II-81(5-(8-ethynyl-6-(pyridin-2-yl)-4H-benzo[f]imidazo[1,5-a][1,4]diazepin-3- yl)oxazole) and analogs selectively potentiate GABAA receptors containing α2/3 subunits and have recently been shown to attenuate pain behaviors in several acute and chronic pain models in rodents. The present study was designed to ascertain whether KRM-II-81 and the structural analog MP-III-80 (3-ethyl-5-(8-ethynyl-6-(pyridin-2-yl)-4H-benzo[f]imidazo[1,5-a][1,4]diazepin-3-yl)-1,2,4-oxadiazole) would block chemotherapeutic agent paclitaxel-induced pain in male, C57BL/6 mice. Both compounds significantly inhibited pain behaviors evoked by cold and tactile stimulation in paclitaxel-treated mice as did the neuropathic pain drug gabapentin. Subchronic dosing for 22 days with KRM-II-81 and MP-III-80 demonstrated enduring analgesic efficacy without tolerance development, while the effects of gabapentin showed evidence of tolerance development. KRM-II-81 and MP-III-80 also decreased marble-burying behavior in this mouse strain as did the anxiolytic drug chlordiazepoxide. In contrast to KRM-II-81 and MP-III-80, chlordiazepoxide had motor-impairing effects at anxiolytic-like doses. The data add to the literature documenting that these selective potentiators of α2/3-containing GABAA receptors are effective in a host of animal models used to detect novel analgesic drugs. The anxiolytic-like efficacy of these compounds fits well with the comorbidity of anxiety in patients with chronic pain and cancer.
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Affiliation(s)
- A Biggerstaff
- School of Biological Sciences, Centre for Biodiscovery, Victoria University of Wellington, Wellington, New Zealand
| | - B Kivell
- School of Biological Sciences, Centre for Biodiscovery, Victoria University of Wellington, Wellington, New Zealand
| | - J L Smith
- Laboratory of Antiepileptic Drug Discovery, Peyton Manning Hospital for Children, Ascension St. Vincent, Indianapolis, IN, USA
| | - Md Y Mian
- Department of Chemistry & Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
| | - L K Golani
- Department of Chemistry & Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
| | - F Rashid
- Department of Chemistry & Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
| | - D Sharmin
- Department of Chemistry & Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
| | - D E Knutson
- Department of Chemistry & Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
| | - R Cerne
- Laboratory of Antiepileptic Drug Discovery, Peyton Manning Hospital for Children, Ascension St. Vincent, Indianapolis, IN, USA; Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška cesta 4, Ljubljana, Slovenia
| | - J M Cook
- Department of Chemistry & Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
| | - J M Witkin
- Laboratory of Antiepileptic Drug Discovery, Peyton Manning Hospital for Children, Ascension St. Vincent, Indianapolis, IN, USA; Department of Chemistry & Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, WI, USA; Departments of Neuroscience and Trauma Research, Ascension St. Vincent Hospital, Indianapolis, IN, USA.
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12
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Duke AN, Platt DM, Rowlett JK. Tolerance and dependence following chronic alprazolam treatment: quantitative observation studies in female rhesus monkeys. Psychopharmacology (Berl) 2020; 237:1183-1194. [PMID: 31927603 PMCID: PMC7988478 DOI: 10.1007/s00213-019-05447-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Accepted: 12/27/2019] [Indexed: 11/28/2022]
Abstract
RATIONALE In order to understand mechanisms underlying tolerance and dependence following chronic benzodiazepine treatments, quantitative and reproducible behavioral models of these phenomena are required. OBJECTIVES This research evaluated the ability of chronic treatment with a commonly prescribed benzodiazepine, alprazolam, to induce tolerance to sedative effects and physical dependence using a novel set of behavioral measurements in rhesus monkeys. METHODS Four female rhesus monkeys (Macaca mulatta) were implanted with chronic intravenous catheters and administered i.v. alprazolam (1.0 mg/kg every 4 h, 38 days total). Quantitative observation measures were obtained during the 38 days of treatment. Acute administration of the benzodiazepine receptor antagonist flumazenil (0.1, 0.3 mg/kg, i.v.) was given to assess precipitated withdrawal. On day 39, saline was substituted for alprazolam and withdrawal signs were assessed for 7 days. RESULTS Maximal sedation ("deep sedation") was evident on day 1 but was not significantly different from baseline levels by day 4 and was absent for the remainder of the 38 days of treatment. A milder form of sedation, "rest/sleep posture," emerged by day 3 and did not decline over 38 days. Cessation of alprazolam treatment resulted in significant withdrawal signs (nose rub, vomit, procumbent posture, tremor/jerk, rigid posture) that dissipated by day 3. These signs also were observed with flumazenil (0.3 mg/kg). CONCLUSIONS Chronic alprazolam treatment resulted in rapid tolerance to some behaviors (e.g., deep sedation) but no tolerance to others (e.g., rest/sleep posture). Physical dependence was observed via both spontaneous and precipitated withdrawal. Based on previous research, these phenomena may reflect differential plasticity at GABAA receptor subtypes.
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Affiliation(s)
- Angela N Duke
- Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS, 39216, USA.,New England Primate Research Center, Harvard Medical School, One Pine Hill Drive, Southborough, MA, 01772, USA.,Wake Forest Baptist Medical Center, Winston-Salem, NC, USA
| | - Donna M Platt
- Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS, 39216, USA.,New England Primate Research Center, Harvard Medical School, One Pine Hill Drive, Southborough, MA, 01772, USA
| | - James K Rowlett
- Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS, 39216, USA. .,New England Primate Research Center, Harvard Medical School, One Pine Hill Drive, Southborough, MA, 01772, USA.
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13
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Foitzick MF, Medina NB, Iglesias García LC, Gravielle MC. Benzodiazepine exposure induces transcriptional down-regulation of GABA A receptor α1 subunit gene via L-type voltage-gated calcium channel activation in rat cerebrocortical neurons. Neurosci Lett 2020; 721:134801. [PMID: 32007495 DOI: 10.1016/j.neulet.2020.134801] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 01/24/2020] [Accepted: 01/30/2020] [Indexed: 01/10/2023]
Abstract
GABAA receptors are targets of different pharmacologically relevant drugs, such as barbiturates, benzodiazepines, and anesthetics. In particular, benzodiazepines are prescribed for the treatment of anxiety, sleep disorders, and seizure disorders. Benzodiazepines potentiate GABA responses by binding to GABAA receptors, which are mainly composed of α (1-3, 5), β2, and γ2 subunits. Prolonged activation of GABAA receptors by endogenous and exogenous modulators induces adaptive changes that lead to tolerance. For example, chronic administration of benzodiazepines produces tolerance to most of their pharmacological actions, limiting their usefulness. The mechanism of benzodiazepine tolerance is still unknown. To investigate the molecular basis of tolerance, we studied the effect of sustained exposure of rat cerebral cortical neurons to diazepam on the GABAA receptor. Flunitrazepam binding experiments showed that diazepam treatment induced uncoupling between GABA and benzodiazepine sites, which was blocked by co-incubation with flumazenil, picrotoxin, or nifedipine. Diazepam also produced selective transcriptional down-regulation of GABAA receptor α1 subunit gene through a mechanism dependent on the activation of L-type voltage-gated calcium channels. These findings suggest benzodiazepine-induced stimulation of calcium influx through L-type voltage-gated calcium channels triggers the activation of a signaling pathway that leads to uncoupling and an alteration of receptor subunit expression. Insights into the mechanism of benzodiazepine tolerance will contribute to the design of new drugs that can maintain their efficacies after long-term treatments.
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Affiliation(s)
- María Florencia Foitzick
- Instituto de Investigaciones Farmacológicas (ININFA), Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires. CONICET, Buenos Aires, Argentina
| | - Nelsy Beatriz Medina
- Instituto de Investigaciones Farmacológicas (ININFA), Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires. CONICET, Buenos Aires, Argentina
| | - Lucía Candela Iglesias García
- Instituto de Investigaciones Farmacológicas (ININFA), Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires. CONICET, Buenos Aires, Argentina
| | - María Clara Gravielle
- Instituto de Investigaciones Farmacológicas (ININFA), Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires. CONICET, Buenos Aires, Argentina.
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14
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Kwakowsky A, Calvo-Flores Guzmán B, Pandya M, Turner C, Waldvogel HJ, Faull RL. GABA A receptor subunit expression changes in the human Alzheimer's disease hippocampus, subiculum, entorhinal cortex and superior temporal gyrus. J Neurochem 2019; 145:374-392. [PMID: 29485232 DOI: 10.1111/jnc.14325] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Revised: 01/17/2018] [Accepted: 02/12/2018] [Indexed: 12/14/2022]
Abstract
Gamma-aminobutyric acid (GABA) is the primary inhibitory neurotransmitter in the central nervous system. GABA type A receptors (GABAA Rs) are severely affected in Alzheimer's disease (AD). However, the distribution and subunit composition of GABAA Rs in the AD brain are not well understood. This is the first comprehensive study to show brain region- and cell layer-specific alterations in the expression of the GABAA R subunits α1-3, α5, β1-3 and γ2 in the human AD hippocampus, entorhinal cortex and superior temporal gyrus. In late-stage AD tissue samples using immunohistochemistry we found significant alteration of all investigated GABAA Rs subunits except for α3 and β1 that were well preserved. The most prominent changes include an increase in GABAA R α1 expression associated with AD in all layers of the CA3 region, in the stratum (str.) granulare and hilus of the dentate gyrus. We found a significant increase in GABAA R α2 expression in the str. oriens of the CA1-3, str. radiatum of the CA2,3 and decrease in the str. pyramidale of the CA1 region in AD cases. In AD there was a significant increase in GABAA R α5 subunit expression in str. pyramidale, str. oriens of the CA1 region and decrease in the superior temporal gyrus. We also found a significant decrease in the GABAA R β3 subunit immunoreactivity in the str. oriens of the CA2, str. granulare and str. moleculare of the dentate gyrus. In conclusion, these findings indicate that the expression of the GABAA R subunits shows brain region- and layer-specific alterations in AD, and these changes could significantly influence and alter GABAA R function in the disease. Cover Image for this issue: doi: 10.1111/jnc.14179.
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Affiliation(s)
- Andrea Kwakowsky
- Centre for Brain Research, Department of Anatomy and Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Beatriz Calvo-Flores Guzmán
- Centre for Brain Research, Department of Anatomy and Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Madhavi Pandya
- Centre for Brain Research, Department of Anatomy and Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Clinton Turner
- Centre for Brain Research, Department of Anatomy and Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand.,Department of Anatomical Pathology, LabPlus, Auckland City Hospital, Auckland, New Zealand
| | - Henry J Waldvogel
- Centre for Brain Research, Department of Anatomy and Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Richard L Faull
- Centre for Brain Research, Department of Anatomy and Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
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15
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Lorenz-Guertin JM, Bambino MJ, Das S, Weintraub ST, Jacob TC. Diazepam Accelerates GABA AR Synaptic Exchange and Alters Intracellular Trafficking. Front Cell Neurosci 2019; 13:163. [PMID: 31080408 PMCID: PMC6497791 DOI: 10.3389/fncel.2019.00163] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 04/08/2019] [Indexed: 12/21/2022] Open
Abstract
Despite 50+ years of clinical use as anxiolytics, anti-convulsants, and sedative/hypnotic agents, the mechanisms underlying benzodiazepine (BZD) tolerance are poorly understood. BZDs potentiate the actions of gamma-aminobutyric acid (GABA), the primary inhibitory neurotransmitter in the adult brain, through positive allosteric modulation of γ2 subunit containing GABA type A receptors (GABAARs). Here we define key molecular events impacting γ2 GABAAR and the inhibitory synapse gephyrin scaffold following initial sustained BZD exposure in vitro and in vivo. Using immunofluorescence and biochemical experiments, we found that cultured cortical neurons treated with the classical BZD, diazepam (DZP), presented no substantial change in surface or synaptic levels of γ2-GABAARs. In contrast, both γ2 and the postsynaptic scaffolding protein gephyrin showed diminished total protein levels following a single DZP treatment in vitro and in mouse cortical tissue. We further identified DZP treatment enhanced phosphorylation of gephyrin Ser270 and increased generation of gephyrin cleavage products. Selective immunoprecipitation of γ2 from cultured neurons revealed enhanced ubiquitination of this subunit following DZP exposure. To assess novel trafficking responses induced by DZP, we employed a γ2 subunit containing an N terminal fluorogen-activating peptide (FAP) and pH-sensitive green fluorescent protein (γ2pHFAP). Live-imaging experiments using γ2pHFAP GABAAR expressing neurons identified enhanced lysosomal targeting of surface GABAARs and increased overall accumulation in vesicular compartments in response to DZP. Using fluorescence resonance energy transfer (FRET) measurements between α2 and γ2 subunits within a GABAAR in neurons, we identified reductions in synaptic clusters of this subpopulation of surface BZD sensitive receptor. Additional time-series experiments revealed the gephyrin regulating kinase ERK was inactivated by DZP at multiple time points. Moreover, we found DZP simultaneously enhanced synaptic exchange of both γ2-GABAARs and gephyrin using fluorescence recovery after photobleaching (FRAP) techniques. Finally we provide the first proteomic analysis of the BZD sensitive GABAAR interactome in DZP vs. vehicle treated mice. Collectively, our results indicate DZP exposure elicits down-regulation of gephyrin scaffolding and BZD sensitive GABAAR synaptic availability via multiple dynamic trafficking processes.
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Affiliation(s)
- Joshua M. Lorenz-Guertin
- Department of Pharmacology and Chemical Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States
| | - Matthew J. Bambino
- Department of Pharmacology and Chemical Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States
| | - Sabyasachi Das
- Department of Pharmacology and Chemical Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States
| | - Susan T. Weintraub
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States
| | - Tija C. Jacob
- Department of Pharmacology and Chemical Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States
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16
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Antkowiak B, Rammes G. GABA(A) receptor-targeted drug development -New perspectives in perioperative anesthesia. Expert Opin Drug Discov 2019; 14:683-699. [DOI: 10.1080/17460441.2019.1599356] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Bernd Antkowiak
- Department of Anesthesiology and Intensive Care, Experimental Anesthesiology Section, Eberhard-Karls-University,
Tübingen, Germany
- Department of Anaesthesiology and Intensive Care, Experimental Anaesthesiology Section, Werner Reichardt Center for Integrative Neuroscience, Tübingen,
Germany
| | - Gerhard Rammes
- University Hospital rechts der Isar, Department of Anesthesiology, München,
Germany
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17
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Nicholson MW, Sweeney A, Pekle E, Alam S, Ali AB, Duchen M, Jovanovic JN. Diazepam-induced loss of inhibitory synapses mediated by PLCδ/ Ca 2+/calcineurin signalling downstream of GABAA receptors. Mol Psychiatry 2018; 23:1851-1867. [PMID: 29904150 PMCID: PMC6232101 DOI: 10.1038/s41380-018-0100-y] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2017] [Revised: 04/09/2018] [Accepted: 05/01/2018] [Indexed: 11/29/2022]
Abstract
Benzodiazepines facilitate the inhibitory actions of GABA by binding to γ-aminobutyric acid type A receptors (GABAARs), GABA-gated chloride/bicarbonate channels, which are the key mediators of transmission at inhibitory synapses in the brain. This activity underpins potent anxiolytic, anticonvulsant and hypnotic effects of benzodiazepines in patients. However, extended benzodiazepine treatments lead to development of tolerance, a process which, despite its important therapeutic implications, remains poorly characterised. Here we report that prolonged exposure to diazepam, the most widely used benzodiazepine in clinic, leads to a gradual disruption of neuronal inhibitory GABAergic synapses. The loss of synapses and the preceding, time- and dose-dependent decrease in surface levels of GABAARs, mediated by dynamin-dependent internalisation, were blocked by Ro 15-1788, a competitive benzodiazepine antagonist, and bicuculline, a competitive GABA antagonist, indicating that prolonged enhancement of GABAAR activity by diazepam is integral to the underlying molecular mechanism. Characterisation of this mechanism has revealed a metabotropic-type signalling downstream of GABAARs, involving mobilisation of Ca2+ from the intracellular stores and activation of the Ca2+/calmodulin-dependent phosphatase calcineurin, which, in turn, dephosphorylates GABAARs and promotes their endocytosis, leading to disassembly of inhibitory synapses. Furthermore, functional coupling between GABAARs and Ca2+ stores was sensitive to phospholipase C (PLC) inhibition by U73122, and regulated by PLCδ, a PLC isoform found in direct association with GABAARs. Thus, a PLCδ/Ca2+/calcineurin signalling cascade converts the initial enhancement of GABAARs by benzodiazepines to a long-term downregulation of GABAergic synapses, this potentially underpinning the development of pharmacological and behavioural tolerance to these widely prescribed drugs.
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Affiliation(s)
| | - Aaron Sweeney
- UCL School of Pharmacy, University College London, London, WC1N 1AX, UK
| | - Eva Pekle
- UCL School of Pharmacy, University College London, London, WC1N 1AX, UK
| | - Sabina Alam
- UCL School of Pharmacy, University College London, London, WC1N 1AX, UK
| | - Afia B Ali
- UCL School of Pharmacy, University College London, London, WC1N 1AX, UK
| | - Michael Duchen
- Neuroscience, Physiology and Pharmacology, University College London, WC1E 6BT, London, UK
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18
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Duarte FS, Duzzioni M, Prim RL, Cardozo AM, Dos Santos CR, da Silva MG, Shiozawa MBC, Mendes BG, Tizziani T, Brighente IMC, Pizzolatti MG, de Lima TCM. Psychopharmacological effects and safety of styryl-2-pyrones and dihydrostyryl-2-pyrones-rich fraction from Polygala sabulosa: absence of withdrawal syndrome and tolerance to anxiolytic-like and anticonvulsant effects. ACTA ACUST UNITED AC 2018; 70:1272-1286. [PMID: 29956326 PMCID: PMC6099234 DOI: 10.1111/jphp.12960] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Accepted: 06/04/2018] [Indexed: 02/06/2023]
Abstract
Objectives To investigate whether mice develop tolerance to the anxiolytic‐like and anticonvulsant effects of subchronic treatment with EA (the styryl‐2‐pyrones and dihydrostyryl‐2‐pyrones‐rich fraction of Polygala sabulosa), as well as any withdrawal symptoms after abrupt discontinuation; to compare the effects of EA with those of diazepam (DZP) on withdrawal‐induced anxiety; and to evaluate the toxicity of EA according to OECD guidelines. Methods Male or female mice were acutely or subchronically treated with EA or DZP, and their tolerance to anxiolytic (evaluated in the elevated plus maze, EPM) and anticonvulsant effects (measured against pentylenetetrazole (PTZ)‐induced convulsions) were investigated. Other groups received EA or DZP for 28 days followed by withdrawal, being the anxiety‐like behaviour evaluated in the EPM. Key findings Both acute and subchronic treatments with EA induced an anxiolytic effect in the EPM. The anticonvulsant activity of DZP, but not EA, was reduced by protracted treatment. EA withdrawal retained the anxiolytic profile, while DZP withdrawal induced anxiogenesis. EA counteracted the anxiogenic‐like actions of DZP withdrawal. EA has low toxicity as it did not cause any changes in the biochemical, haematological and histopathological markers. Conclusions EA avoids the development of tolerance to its anxiolytic‐like and anticonvulsant actions, and does not promote withdrawal syndrome. EA does not cause relevant toxic effects in rodents.
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Affiliation(s)
- Filipe Silveira Duarte
- Department of Physiology and Pharmacology, Federal University of Pernambuco, Recife, Pernambuco, Brazil
| | - Marcelo Duzzioni
- Institute of Biological Sciences and Health, Federal University of Alagoas, Maceió, Alagoas, Brazil
| | - Rafael Luiz Prim
- Department of Pathology, Federal University of Santa Catarina, Florianópolis, Santa Catarina, Brazil
| | - Alcíbia Maia Cardozo
- Department of Pathology, Federal University of Santa Catarina, Florianópolis, Santa Catarina, Brazil
| | - Claudia Regina Dos Santos
- Department of Pathology, Federal University of Santa Catarina, Florianópolis, Santa Catarina, Brazil
| | - Maria Goretti da Silva
- Department of Pathology, Federal University of Santa Catarina, Florianópolis, Santa Catarina, Brazil
| | | | - Beatriz Garcia Mendes
- Department of Chemistry, Federal University of Santa Catarina, Florianópolis, Santa Catarina, Brazil
| | - Tiago Tizziani
- Department of Chemistry, Federal University of Santa Catarina, Florianópolis, Santa Catarina, Brazil
| | | | - Moacir Geraldo Pizzolatti
- Department of Chemistry, Federal University of Santa Catarina, Florianópolis, Santa Catarina, Brazil
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19
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Pottie K, Thompson W, Davies S, Grenier J, Sadowski CA, Welch V, Holbrook A, Boyd C, Swenson R, Ma A, Farrell B. [Not Available]. CANADIAN FAMILY PHYSICIAN MEDECIN DE FAMILLE CANADIEN 2018; 64:e209-e224. [PMID: 29760269 PMCID: PMC5951664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Objectif Formuler des lignes directrices fondées sur les données probantes visant à aider les cliniciens à décider du moment et de la façon sécuritaire de réduire la dose des agonistes des récepteurs des benzodiazépines (BZRA) pour mettre fin au traitement; se concentrer sur le niveau le plus élevé des données disponibles et obtenir les commentaires des professionnels de première ligne durant le processus de rédaction, de révision et d’adoption des lignes directrices. Méthodes L’équipe comptait 8 cliniciens (1 médecin de famille, 2 psychiatres, 1 psychologue clinique, 1 pharmacologue clinique, 2 pharmaciennes cliniques et 1 gériatre) et une spécialiste de la méthodologie; les membres ont divulgué tout conflit d’intérêts. Nous avons eu recours à un processus systématique, y compris l’approche GRADE (Grading of Recommendations Assessment, Development and Evaluation) pour formuler les lignes directrices. Les données ont été générées par une revue systématique d’études portant sur la déprescription des BZRA contre l’insomnie, de même que par une revue des revues sur les torts liés à la poursuite du traitement par BZRA et des synthèses narratives sur les préférences des patients et les répercussions sur les ressources. Ces données et le score GRADE de qualité des données ont servi à formuler les recommandations. L’équipe a peaufiné le texte sur le contenu et les recommandations des lignes directrices par consensus et a synthétisé les considérations cliniques afin de répondre aux questions des cliniciens de première ligne. Une version préliminaire des lignes directrices a été révisée par les cliniciens et les intervenants. Recommandations Nous recommandons d’offrir la déprescription (réduction lente de la dose) des BZRA à tous les patients âgés (≥ 65 ans) sous un BZRA, sans égard à la durée de l’usage, et suggérons d’offrir la déprescription (réduction lente de la dose) à tous les adultes de 18 à 64 qui prennent un BZRA depuis plus de 4 semaines. Ces recommandations visent les patients qui prennent un BZRA contre l’insomnie seule (insomnie primaire) ou l’insomnie comorbide lorsque les comorbidités sous-jacentes sont efficacement prises en charge. Ces lignes directrices ne visent pas les personnes atteintes d’autres troubles non traités du sommeil ou d’anxiété, de dépression, ou d’autres troubles physiques ou de santé mentale pouvant causer ou aggraver l’insomnie. Conclusion Les agonistes des récepteurs des benzodiazépines sont liés à des torts, et leur effet thérapeutique serait bref. La réduction graduelle de la dose de BZRA améliore le taux d’abandon comparativement aux soins habituels, et ce, sans causer de torts graves. Les patients seraient plus ouverts à une conversation sur la déprescription s’ils comprennent le pourquoi (potentiel de torts), participent à l’élaboration du plan de réduction de la dose et reçoivent des conseils en matière de comportement. Les présentes lignes directrices émettent des recommandations pour décider du moment et de la façon de réduire la dose de BZRA pour mettre fin au traitement. Elles visent à contribuer au processus de décision conjointement avec le patient et non à le dicter.
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Affiliation(s)
- Kevin Pottie
- Professeur agrégé au département de médecine familiale et à l'École d'épidémiologie et de santé publique à l'Institut de recherche Bruyère de l'Université d'Ottawa, en Ontario.
| | - Wade Thompson
- Étudiant à la maîtrise à l'École d'épidémiologie et de santé publique de l'Université d'Ottawa
| | - Simon Davies
- Professeur agrégé au département de psychiatrie de l'Université de Toronto, en Ontario, et scientifique clinicien et psychiatre titulaire à la division de gérontopsychiatrie au Centre de toxicomanie et de santé mentale à Toronto
| | - Jean Grenier
- Investigateur clinicien au département de médecine familiale de l'Université d'Ottawa et scientifique clinique au Centre de recherche C.T. Lamont en soins de santé primaire de l'Institut de recherche Bruyère
| | - Cheryl A Sadowski
- Professeure à la faculté de pharmacie et de sciences pharmaceutiques de l'Université de l'Alberta à Edmonton. Lors de l'élaboration des lignes directrices
| | - Vivian Welch
- Directrice du Centre des méthodes à l'Institut de recherche Bruyère et professeure adjointe à l'École d'épidémiologie et de santé publique de l'Université d'Ottawa
| | - Anne Holbrook
- Directrice de la division de pharmacologie clinique et professeure au département de médecine de l'Université McMaster à Hamilton, en Ontario; elle est aussi scientifique principale au Centre for Evaluation of Medicines du St Joseph's Healthcare Hamilton
| | - Cynthia Boyd
- Professeure au département de médecine de la division de médecine gériatrique et de gérontologie à la Johns Hopkins University School of Medicine à Baltimore, MD
| | - Robert Swenson
- Psychiatre à l'Hôpital d'Ottawa et professeur titulaire au département de psychiatrie de l'Université d'Ottawa
| | - Andy Ma
- Résident en pharmacie à l'Hôpital d'Ottawa
| | - Barbara Farrell
- Professeure adjointe au département de médecine familiale de l'Université d'Ottawa, professeure adjointe auxiliaire à l'École de pharmacie de l'Université de Waterloo en Ontario et scientifique à l'Institut de recherche Bruyère
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20
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Pottie K, Thompson W, Davies S, Grenier J, Sadowski CA, Welch V, Holbrook A, Boyd C, Swenson R, Ma A, Farrell B. Deprescribing benzodiazepine receptor agonists: Evidence-based clinical practice guideline. CANADIAN FAMILY PHYSICIAN MEDECIN DE FAMILLE CANADIEN 2018; 64:339-351. [PMID: 29760253 PMCID: PMC5951648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
OBJECTIVE To develop an evidence-based guideline to help clinicians make decisions about when and how to safely taper and stop benzodiazepine receptor agonists (BZRAs); to focus on the highest level of evidence available and seek input from primary care professionals in the guideline development, review, and endorsement processes. METHODS The overall team comprised 8 clinicians (1 family physician, 2 psychiatrists, 1 clinical psychologist, 1 clinical pharmacologist, 2 clinical pharmacists, and 1 geriatrician) and a methodologist; members disclosed conflicts of interest. For guideline development, a systematic process was used, including the GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach. Evidence was generated by conducting a systematic review of BZRA deprescribing trials for insomnia, as well as performing a review of reviews of the harms of continued BZRA use and narrative syntheses of patient preferences and resource implications. This evidence and GRADE quality of evidence ratings were used to generate recommendations. The team refined guideline content and recommendations through consensus and synthesized clinical considerations to address front-line clinician questions. The draft guideline was reviewed by clinicians and stakeholders. RECOMMENDATIONS We recommend that deprescribing (tapering slowly) of BZRAs be offered to elderly adults (≥ 65 years) who take BZRAs, regardless of duration of use, and suggest that deprescribing (tapering slowly) be offered to adults aged 18 to 64 who have used BZRAs for more than 4 weeks. These recommendations apply to patients who use BZRAs to treat insomnia on its own (primary insomnia) or comorbid insomnia where potential underlying comorbidities are effectively managed. This guideline does not apply to those with other sleep disorders or untreated anxiety, depression, or other physical or mental health conditions that might be causing or aggravating insomnia. CONCLUSION Benzodiazepine receptor agonists are associated with harms, and therapeutic effects might be short term. Tapering BZRAs improves cessation rates compared with usual care without serious harms. Patients might be more amenable to deprescribing conversations if they understand the rationale (potential for harm), are involved in developing the tapering plan, and are offered behavioural advice. This guideline provides recommendations for making decisions about when and how to reduce and stop BZRAs. Recommendations are meant to assist with, not dictate, decision making in conjunction with patients.
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Affiliation(s)
- Kevin Pottie
- Associate Professor in the Department of Family Medicine and the Department of Epidemiology and Community Medicine at the Bruyère Research Institute at the University of Ottawa in Ontario.
| | - Wade Thompson
- Master's student in the School of Epidemiology and Public Health at the University of Ottawa at the time of guideline development
| | - Simon Davies
- Associate Professor in the Department of Psychiatry at the University of Toronto in Ontario and Clinician Scientist and staff psychiatrist in the Geriatric Psychiatry Division at the Centre for Addiction and Mental Health in Toronto
| | - Jean Grenier
- Clinician Investigator in the Department of Family Medicine at the University of Ottawa and Clinical Scientist at the C.T. Lamont Centre for Primary Health Care Research of the Bruyère Research Institute
| | - Cheryl A Sadowski
- Professor in the Faculty of Pharmacy and Pharmaceutical Sciences at the University of Alberta in Edmonton
| | - Vivian Welch
- Director of the Methods Centre at the Bruyère Research Institute and Assistant Professor in the School of Epidemiology and Public Health at the University of Ottawa at the time of guideline development
| | - Anne Holbrook
- Director of the Division of Clinical Pharmacology and Professor in the Department of Medicine at McMaster University in Hamilton, Ont, and Senior Scientist at the Centre for Evaluation of Medicines of St Joseph's Healthcare Hamilton
| | - Cynthia Boyd
- Professor in the Department of Medicine in the Division of Geriatric Medicine and Gerontology at the Johns Hopkins University School of Medicine in Baltimore, MD
| | - Robert Swenson
- Psychiatrist at the Ottawa Hospital and Full Professor in the Department of Psychiatry at the University of Ottawa
| | - Andy Ma
- Pharmacy resident at the Ottawa Hospital
| | - Barbara Farrell
- Assistant Professor in the Department of Family Medicine at the University of Ottawa, Adjunct Assistant Professor in the School of Pharmacy at the University of Waterloo in Ontario, and Scientist at the Bruyère Research Institute
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21
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Anxiolytic-Like Effect of Methanol Leaf Extract of Laggera aurita Linn. F. (Asteraceae) in Mice. ARCHIVES OF NEUROSCIENCE 2018. [DOI: 10.5812/archneurosci.63441] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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22
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Cai H, Cao T, Zhou X, Yao JK. Neurosteroids in Schizophrenia: Pathogenic and Therapeutic Implications. Front Psychiatry 2018; 9:73. [PMID: 29568275 PMCID: PMC5852066 DOI: 10.3389/fpsyt.2018.00073] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Accepted: 02/21/2018] [Indexed: 12/11/2022] Open
Abstract
Neurosteroids are a group of important endogenous molecules affecting many neural functions in the brain. Increasing evidence suggests a possible role of these neurosteroids in the pathology and symptomatology of schizophrenia (SZ) and other mental disorders. The aim of this review is to summarize the current knowledge about the neural functions of neurosteroids in the brain, and to evaluate the role of the key neurosteroids as candidate modulators in the etiology and therapeutics of SZ. The present paper provides a brief introduction of neurosteroid metabolism and distribution, followed by a discussion of the mechanisms underlying neurosteroid actions in the brain. The content regarding the modulation of the GABAA receptor is elaborated, given the considerable knowledge of its interactions with other neurotransmitter and neuroprotective systems, as well as its ameliorating effects on stress that may play a role in the SZ pathophysiology. In addition, several preclinical and clinical studies suggested a therapeutic benefit of neurosteroids in SZ patients, even though the presence of altered neurosteroid pathways in the circulating blood and/or brain remains debatable. Following treatment of antipsychotic drugs in SZ, therapeutic benefits have also been linked to the regulation of neurosteroid signaling. Specifically, the neurosteroids such as pregnenolone and dehydroepiandrosterone affect a broad spectrum of behavioral functions through their unique molecular characteristics and may represent innovative therapeutic targets for SZ. Future investigations in larger cohorts with long-term follow-ups will be required to ascertain the neuropsychopharmacological role of this yet unexploited class of neurosteroid agents.
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Affiliation(s)
- HuaLin Cai
- Department of Pharmacy, The Second Xiangya Hospital of Central South University, Changsha, China
- The Institute of Clinical Pharmacy, Central South University, Changsha, China
| | - Ting Cao
- Department of Pharmacy, The Second Xiangya Hospital of Central South University, Changsha, China
- The Institute of Clinical Pharmacy, Central South University, Changsha, China
| | - Xiang Zhou
- Medical Research Service, VA Pittsburgh Healthcare System, Pittsburgh, PA, United States
- Department of Pharmaceutical Sciences, University of Pittsburgh School of Pharmacy, Pittsburgh, PA, United States
| | - Jeffrey K. Yao
- Medical Research Service, VA Pittsburgh Healthcare System, Pittsburgh, PA, United States
- Department of Pharmaceutical Sciences, University of Pittsburgh School of Pharmacy, Pittsburgh, PA, United States
- Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
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23
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Cheng T, Wallace DM, Ponteri B, Tuli M. Valium without dependence? Individual GABA A receptor subtype contribution toward benzodiazepine addiction, tolerance, and therapeutic effects. Neuropsychiatr Dis Treat 2018; 14:1351-1361. [PMID: 29872302 PMCID: PMC5973310 DOI: 10.2147/ndt.s164307] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Benzodiazepines are one of the most prescribed medications as first-line treatment of anxiety, insomnia, and epilepsy around the world. Over the past two decades, advances in the neuropharmacological understanding of gamma aminobutyric acid (GABA)A receptors revealed distinct contributions from each subtype and produced effects. Recent findings have highlighted the importance of α1 containing GABAA receptors in the mechanisms of addiction and tolerance in benzodiazepine treatments. This has shown promise in the development of tranquilizers with minimal side effects such as cognitive impairment, dependence, and tolerance. A valium-like drug without its side effects, as repeatedly demonstrated in animals, is achievable.
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Affiliation(s)
| | | | | | - Mahir Tuli
- University of British Columbia, Vancouver, BC, Canada
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24
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Wang X, Chen Y, Wang Q, Sun L, Li G, Zhang C, Huang J, Chen L, Zhai H. Support for Natural Small-Molecule Phenols as Anxiolytics. Molecules 2017; 22:molecules22122138. [PMID: 29210995 PMCID: PMC6150002 DOI: 10.3390/molecules22122138] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2017] [Revised: 11/30/2017] [Accepted: 11/30/2017] [Indexed: 01/29/2023] Open
Abstract
Natural small-molecule phenols (NSMPs) share some bioactivities. The anxiolytic activity of NSMPs is attracting attention in the scientific community. This paper provides data supporting the hypothesis that NSMPs are generally anxiolytic. The anxiolytic activities of seven simple phenols, including phloroglucinol, eugenol, protocatechuic aldehyde, vanillin, thymol, ferulic acid, and caffeic acid, were assayed with the elevated plus maze (EPM) test in mice. The oral doses were 5, 10 and 20 mg/kg, except for phloroglucinol for which the doses were 2.5, 5 and 10 mg/kg. All tested phenols had anxiolytic activity in mice. The phenolic hydroxyl group in 4-hydroxycinnamic acid (4-OH CA) was essential for the anxiolytic activity in the EPM test in mice and rats compared to 4-chlorocinnamic acid (4-Cl CA). The in vivo spike recording of rats’ hippocampal neurons also showed significant differences between 4-OH CA and 4-Cl CA. Behavioral and neuronal spike recording results converged to indicate the hippocampal CA1 region might be a part of the anxiolytic pathways of 4-OH CA. Therefore, our study provides further experimental data supporting NSMPs sharing anxiolytic activity, which may have general implications for phytotherapy because small phenols occur extensively in herbal medicines.
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Affiliation(s)
- Xiaohong Wang
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Liangxiang Town, Fangshan District, Beijing 102488, China.
| | - Yahong Chen
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Liangxiang Town, Fangshan District, Beijing 102488, China.
| | - Qiang Wang
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Liangxiang Town, Fangshan District, Beijing 102488, China.
| | - Lu Sun
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Liangxiang Town, Fangshan District, Beijing 102488, China.
| | - Guiyun Li
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Liangxiang Town, Fangshan District, Beijing 102488, China.
| | - Chanxi Zhang
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Liangxiang Town, Fangshan District, Beijing 102488, China.
| | - Jianmei Huang
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Liangxiang Town, Fangshan District, Beijing 102488, China.
| | - Lei Chen
- National Institute on Drug Dependence, Peking University, 38#, Xueyuan Road, Haidian District, Beijing 100191, China.
| | - Haifeng Zhai
- National Institute on Drug Dependence, Peking University, 38#, Xueyuan Road, Haidian District, Beijing 100191, China.
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25
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Shergis JL, Ni X, Sarris J, Zhang AL, Guo X, Xue CC, Lu C, Hugel H. Ziziphus spinosa seeds for insomnia: A review of chemistry and psychopharmacology. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2017; 34:38-43. [PMID: 28899507 DOI: 10.1016/j.phymed.2017.07.004] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Revised: 05/28/2017] [Accepted: 07/02/2017] [Indexed: 06/07/2023]
Abstract
BACKGROUND In Chinese medicine, Ziziphus jujuba Mill. var. spinosa (Bunge) Hu ex H. F. Chou is widely used for the treatment of insomnia. PURPOSE/SECTIONS This paper summarises the chemistry, psychopharmacology, and compares the pharmaceutical effects of the seeds of Ziziphus jujuba plant, Ziziphus spinosa (ZS) seeds, with benzodiazepines. Whole extracts and constituent compounds have been evaluated in preclinical and clinical studies. CONCLUSIONS ZS secondary metabolites modulate GABAergic activity and the serotonergic system. The actual therapeutic agents require further confirmation/identification so that new insomnia phytomedicines can be discovered.
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Affiliation(s)
- Johannah Linda Shergis
- China-Australia International Research Centre for Chinese Medicine, School of Health and Biomedical Sciences, RMIT University, PO Box 71, Bundoora 3083, Australia
| | - Xiaojia Ni
- China-Australia International Research Centre for Chinese Medicine, School of Health and Biomedical Sciences, RMIT University, PO Box 71, Bundoora 3083, Australia; Guangdong Provincial Hospital of Chinese Medicine, Guangdong Provincial Academy of Chinese Medical Sciences, and The Second Clinical College, Guangzhou University of Chinese Medicine, 111 Dade Road, Yuexiu District, Guangzhou 510120, PR China
| | - Jerome Sarris
- Department of Psychiatry and The Melbourne Clinic, The University of Melbourne, Victoria 3121, Australia; Centre for Human Psychopharmacology, Swinburne University of Technology, PO Box 218, Hawthorn 3122, Victoria, Australia
| | - Anthony Lin Zhang
- China-Australia International Research Centre for Chinese Medicine, School of Health and Biomedical Sciences, RMIT University, PO Box 71, Bundoora 3083, Australia
| | - Xinfeng Guo
- Guangdong Provincial Hospital of Chinese Medicine, Guangdong Provincial Academy of Chinese Medical Sciences, and The Second Clinical College, Guangzhou University of Chinese Medicine, 111 Dade Road, Yuexiu District, Guangzhou 510120, PR China
| | - Charlie C Xue
- China-Australia International Research Centre for Chinese Medicine, School of Health and Biomedical Sciences, RMIT University, PO Box 71, Bundoora 3083, Australia; Guangdong Provincial Hospital of Chinese Medicine, Guangdong Provincial Academy of Chinese Medical Sciences, and The Second Clinical College, Guangzhou University of Chinese Medicine, 111 Dade Road, Yuexiu District, Guangzhou 510120, PR China
| | - Chuanjian Lu
- Guangdong Provincial Hospital of Chinese Medicine, Guangdong Provincial Academy of Chinese Medical Sciences, and The Second Clinical College, Guangzhou University of Chinese Medicine, 111 Dade Road, Yuexiu District, Guangzhou 510120, PR China.
| | - Helmut Hugel
- School of Science, RMIT University, PO Box 2476, Melbourne 3001 VIC, Australia.
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26
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Curcumin Reverses the Diazepam-Induced Cognitive Impairment by Modulation of Oxidative Stress and ERK 1/2/NF- κB Pathway in Brain. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2017; 2017:3037876. [PMID: 29098059 PMCID: PMC5643119 DOI: 10.1155/2017/3037876] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Accepted: 07/06/2017] [Indexed: 12/13/2022]
Abstract
Oxidative stress and inflammation can be involved in cognitive dysfunction associated with neurodegenerative disorders. Diazepam (DZP) administration has been chosen to simulate the memory impairment. The aim of this study was to evaluate the effects of curcumin (CUR) on spatial cognition, ambulatory activity, and blood and brain oxidative stress levels. The ERK/NF-κB signaling pathway and the histopathological changes in the hippocampus and frontal lobe, in diazepam-treated rats, were also analyzed. The animals were divided into 4 groups: control, carboxymethylcellulose (CMC) + CUR, CMC + DZP, and CUR + CMC + DZP. CUR (150 mg/kg b.w.) was orally administered for 28 days. DZP (2 mg/kg b.w.) was intraperitoneally administered 20 minutes before the behavioral tests (open field test, Y-maze, and elevated plus maze). CUR improved the spontaneous alternation behavior, decreased the oxidative stress levels, both in the blood and in the hippocampus, and downregulated the extracellular signal-regulated kinase (ERK 1/2)/nuclear transcription factor- (NF-) κB/pNF-κB pathway in the hippocampus and the iNOS expression in the hippocampus and frontal lobe of the DZP-treated rats. Histopathologically, no microscopic changes were found. The immunohistochemical signal of iNOS decreased in the DZP and CUR-treated group. Thus, our findings suggest that curcumin administration may improve the cognitive performance and may also have an antioxidant effect.
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27
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Kumar M, Kumar M, Freund JM, Dillon GH. A Single Amino Acid Residue at Transmembrane Domain 4 of the α Subunit Influences Carisoprodol Direct Gating Efficacy at GABA A Receptors. J Pharmacol Exp Ther 2017. [PMID: 28642232 DOI: 10.1124/jpet.117.242156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The muscle relaxant carisoprodol has recently been controlled at the federal level as a Schedule IV drug due to its high abuse potential and consequences of misuse, such as withdrawal syndrome, delusions, seizures, and even death. Recent work has shown that carisoprodol can directly gate and allosterically modulate the type A GABA (GABAA) receptor. These actions are subunit-dependent; compared with other GABAA receptors, carisoprodol has nominal direct gating effects in α3β2γ2 receptors. Here, using site-directed mutagenesis and whole-cell patch-clamp electrophysiology in transiently transfected human embryonic kidney 293 cells, we examined the role of GABAA receptor α subunit transmembrane domain 4 (TM4) amino acids in direct gating and allosteric modulatory actions of carisoprodol. Mutation of α3 valine at position 440 to leucine (present in the equivalent position in the α1 subunit) significantly increased the direct gating effects of carisoprodol without affecting its allosteric modulatory effects. The corresponding reverse mutation, α1(L415V), decreased carisoprodol direct gating potency and efficacy. Analysis of a series of amino acid mutations at the 415 position demonstrated that amino acid volume correlated positively with carisoprodol efficacy, whereas polarity inversely correlated with carisoprodol efficacy. We conclude that α1(415) of TM4 is involved in the direct gating, but not allosteric modulatory, actions of carisoprodol. In addition, the orientation of alkyl or hydroxyl groups at this position influences direct gating effects. These findings support the likelihood that the direct gating and allosteric modulatory effects of carisoprodol are mediated via distinct binding sites.
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Affiliation(s)
- Manoj Kumar
- Department of Physiology and Pharmacology, Center for Neuroscience, Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, West Virginia (Mo.K., Mi.K., J.M.F., G.H.D.); and Center for Neuroscience Discovery, Institute for Healthy Aging, University of North Texas Health Science Center, Fort Worth, Texas (Mi.K., G.H.D.)
| | - Manish Kumar
- Department of Physiology and Pharmacology, Center for Neuroscience, Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, West Virginia (Mo.K., Mi.K., J.M.F., G.H.D.); and Center for Neuroscience Discovery, Institute for Healthy Aging, University of North Texas Health Science Center, Fort Worth, Texas (Mi.K., G.H.D.)
| | - John M Freund
- Department of Physiology and Pharmacology, Center for Neuroscience, Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, West Virginia (Mo.K., Mi.K., J.M.F., G.H.D.); and Center for Neuroscience Discovery, Institute for Healthy Aging, University of North Texas Health Science Center, Fort Worth, Texas (Mi.K., G.H.D.)
| | - Glenn H Dillon
- Department of Physiology and Pharmacology, Center for Neuroscience, Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, West Virginia (Mo.K., Mi.K., J.M.F., G.H.D.); and Center for Neuroscience Discovery, Institute for Healthy Aging, University of North Texas Health Science Center, Fort Worth, Texas (Mi.K., G.H.D.)
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28
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Poe MM, Methuku KR, Li G, Verma AR, Teske KA, Stafford DC, Arnold LA, Cramer JW, Jones TM, Cerne R, Krambis MJ, Witkin JM, Jambrina E, Rehman S, Ernst M, Cook JM, Schkeryantz JM. Synthesis and Characterization of a Novel γ-Aminobutyric Acid Type A (GABA A) Receptor Ligand That Combines Outstanding Metabolic Stability, Pharmacokinetics, and Anxiolytic Efficacy. J Med Chem 2016; 59:10800-10806. [PMID: 27933953 DOI: 10.1021/acs.jmedchem.6b01332] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
1,4-Benzodiazepines are used in the treatment of anxiety disorders but have limited long-term use due to adverse effects. HZ-166 (2) has been shown to have anxiolytic-like effects with reduced sedative/ataxic liabilities. A 1,3-oxazole KRM-II-81 (9) was discovered from a series of six bioisosteres with significantly improved pharmacokinetic and pharmacodynamic properties as compared to 2. Oxazole 9 was further characterized and exhibited improved anxiolytic-like effects in a mouse marble burying assay and a rat Vogel conflict test.
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Affiliation(s)
- Michael M Poe
- Department of Chemistry and Biochemistry and the Milwaukee Institute for Drug Discovery, University of Wisconsin-Milwaukee , Milwaukee, Wisconsin 53201, United States
| | - Kashi Reddy Methuku
- Department of Chemistry and Biochemistry and the Milwaukee Institute for Drug Discovery, University of Wisconsin-Milwaukee , Milwaukee, Wisconsin 53201, United States
| | - Guanguan Li
- Department of Chemistry and Biochemistry and the Milwaukee Institute for Drug Discovery, University of Wisconsin-Milwaukee , Milwaukee, Wisconsin 53201, United States
| | - Ashwini R Verma
- Department of Chemistry and Biochemistry and the Milwaukee Institute for Drug Discovery, University of Wisconsin-Milwaukee , Milwaukee, Wisconsin 53201, United States
| | - Kelly A Teske
- Department of Chemistry and Biochemistry and the Milwaukee Institute for Drug Discovery, University of Wisconsin-Milwaukee , Milwaukee, Wisconsin 53201, United States
| | - Douglas C Stafford
- Department of Chemistry and Biochemistry and the Milwaukee Institute for Drug Discovery, University of Wisconsin-Milwaukee , Milwaukee, Wisconsin 53201, United States
| | - Leggy A Arnold
- Department of Chemistry and Biochemistry and the Milwaukee Institute for Drug Discovery, University of Wisconsin-Milwaukee , Milwaukee, Wisconsin 53201, United States
| | - Jeffrey W Cramer
- Lilly Research Laboratories, Eli Lilly and Company , Indianapolis, Indiana 42685, United States
| | - Timothy M Jones
- Lilly Research Laboratories, Eli Lilly and Company , Indianapolis, Indiana 42685, United States
| | - Rok Cerne
- Lilly Research Laboratories, Eli Lilly and Company , Indianapolis, Indiana 42685, United States
| | - Michael J Krambis
- Lilly Research Laboratories, Eli Lilly and Company , Indianapolis, Indiana 42685, United States
| | - Jeffrey M Witkin
- Lilly Research Laboratories, Eli Lilly and Company , Indianapolis, Indiana 42685, United States
| | - Enrique Jambrina
- Lilly Research Laboratories, Eli Lilly and Company , 28108 Alcobendas, Spain
| | - Sabah Rehman
- Department for Molecular Neurosciences, Medical University of Vienna , 1090 Vienna, Austria
| | - Margot Ernst
- Department for Molecular Neurosciences, Medical University of Vienna , 1090 Vienna, Austria
| | - James M Cook
- Department of Chemistry and Biochemistry and the Milwaukee Institute for Drug Discovery, University of Wisconsin-Milwaukee , Milwaukee, Wisconsin 53201, United States
| | - Jeffrey M Schkeryantz
- Lilly Research Laboratories, Eli Lilly and Company , Indianapolis, Indiana 42685, United States
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29
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Chagraoui A, Skiba M, Thuillez C, Thibaut F. To what extent is it possible to dissociate the anxiolytic and sedative/hypnotic properties of GABAA receptors modulators? Prog Neuropsychopharmacol Biol Psychiatry 2016; 71:189-202. [PMID: 27495357 DOI: 10.1016/j.pnpbp.2016.08.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 07/21/2016] [Accepted: 08/01/2016] [Indexed: 01/16/2023]
Abstract
The relatively common view indicates a possible dissociation between the anxiolytic and sedative/hypnotic properties of benzodiazepines (BZs). Indeed, GABAA receptor (GABAAR) subtypes have specific cerebral distribution in distinct neural circuits. Thus, GABAAR subtype-selective drugs may be expected to perform distinct functions. However, standard behavioral test assays provide limited direction towards highlighting new action mechanisms of ligands targeting GABAARs. Automated behavioral tests, lack sensitivity as some behavioral characteristics or subtle behavioral changes of drug effects or that are not considered in the overall analysis (Ohl et al., 2001) and observation-based analyses are not always performed. In addition, despite the use of genetically engineered mice, any possible dissociation between the anxiolytic and sedative properties of BZs remains controversial. Moreover, the involvement the different subtypes of GABAAR subtypes in the anxious behavior and the mechanism of action of anxiolytic agents remains unclear since there has been little success in the pharmacological investigations so far. This raises the question of the involvement of the different subunits in anxiolytic-like and/or sedative effects; and the actual implication of these subunits, particularly, α-subunits in the modulation of sedation and/or anxiety-related disorders. This present review was prompted by several conflicting studies on the degree of involvement of these subunits in anxiolytic-like and/or sedative effects. To this end, we explored the GABAergic system, particularly, the role of different subunits containing synaptic GABAARs. We report herein the targeting gene encoding the different subunits and their contribution in anxiolytic-like and/or sedative actions, as well as, the mechanism underlying tolerance to BZs.
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Affiliation(s)
- A Chagraoui
- Inserm U982, Laboratory of Neuronal and Neuroendocrine Differentiation and Communication, Institute for Research and Innovation in Biomedecine, Normandy University, France; Department of Medical Biochemistry, Rouen University Hospital, Rouen, France.
| | - M Skiba
- Inserm U982, Laboratory of Neuronal and Neuroendocrine Differentiation and Communication, Institute for Research and Innovation in Biomedecine, Normandy University, France
| | - C Thuillez
- Department of Pharmacology, Rouen University Hospital, Rouen, and INSERM U1096, Laboratory of New Pharmacological Targets for Endothelial Protection and Heart Failure, Institute for Research and Innovation in Biomedicine, Normandy University, France
| | - F Thibaut
- Department of Psychiatry, University Hospital Cochin (site Tarnier), University of Paris-Descartes and INSERM U 894 Laboratory of Psychiatry and Neurosciences, Paris, France
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30
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Tsutsui R, Shinomiya K, Sendo T, Kitamura Y, Kamei C. Effects of the 5-HT(1A) Receptor Agonist Tandospirone on ACTH-Induced Sleep Disturbance in Rats. Biol Pharm Bull 2016; 38:884-8. [PMID: 26027828 DOI: 10.1248/bpb.b14-00887] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The aim of this study was to compare the effect of the serotonin (5-HT)1A receptor agonist tandospirone versus that of the benzodiazepine hypnotic flunitrazepam in a rat model of long-term adrenocorticotropic hormone (ACTH)-induced sleep disturbance. Rats implanted with electrodes for recording electroencephalogram and electromyogram were injected with ACTH once daily at a dose of 100 µg/rat. Administration of ACTH for 10 d caused a significant increase in sleep latency, decrease in non-rapid eye movement (non-REM) sleep time, and increase in wake time. Tandospirone caused a significant decrease in sleep latency and increase in non-REM sleep time in rats treated with ACTH. The effect of tandospirone on sleep patterns was antagonized by the 5-HT1A receptor antagonist WAY-100635. In contrast, flunitrazepam had no significant effect on sleep parameters in ACTH-treated rats. These results clearly indicate that long-term administration of ACTH causes sleep disturbance, and stimulating the 5-HT1A receptor by tandospirone may be efficacious for improving sleep in cases in which benzodiazepine hypnotics are ineffective.
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Affiliation(s)
- Ryuki Tsutsui
- Department of Clinical Pharmacy, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University
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Kumar M, Dillon GH. Assessment of direct gating and allosteric modulatory effects of meprobamate in recombinant GABA(A) receptors. Eur J Pharmacol 2016; 775:149-58. [PMID: 26872987 DOI: 10.1016/j.ejphar.2016.02.031] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2015] [Revised: 02/05/2016] [Accepted: 02/08/2016] [Indexed: 02/07/2023]
Abstract
Meprobamate is a schedule IV anxiolytic and the primary metabolite of the muscle relaxant carisoprodol. Meprobamate modulates GABAA (γ-aminobutyric acid Type A) receptors, and has barbiturate-like activity. To gain insight into its actions, we have conducted a series of studies using recombinant GABAA receptors. In αxβzγ2 GABAA receptors (where x=1-6 and z=1-3), the ability to enhance GABA-mediated current was evident for all α subunit isoforms, with the largest effect observed in α5-expressing receptors. Direct gating was present with all α subunits, although attenuated in α3-expressing receptors. Allosteric and direct effects were comparable in α1β1γ2 and α1β2γ2 receptors, whereas allosteric effects were enhanced in α1β2 compared to α1β2γ2 receptors. In "extrasynaptic" (α1β3δ and α4β3δ) receptors, meprobamate enhanced EC20 and saturating GABA currents, and directly activated these receptors. The barbiturate antagonist bemegride attenuated direct effects of meprobamate. Whereas pentobarbital directly gated homomeric β3 receptors, meprobamate did not, and instead blocked the spontaneously open current present in these receptors. In wild type homomeric ρ1 receptors, pentobarbital and meprobamate were ineffective in direct gating; a mutation known to confer sensitivity to pentobarbital did not confer sensitivity to meprobamate. Our results provide insight into the actions of meprobamate and parent therapeutic agents such as carisoprodol. Whereas in general actions of meprobamate were comparable to those of carisoprodol, differential effects of meprobamate at some receptor subtypes suggest potential advantages of meprobamate may be exploited. A re-assessment of previously synthesized meprobamate-related carbamate molecules for myorelaxant and other therapeutic indications is warranted.
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Affiliation(s)
- Manish Kumar
- Department of Physiology and Pharmacology and Center for Neuroscience, Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, WV, USA
| | - Glenn H Dillon
- Department of Physiology and Pharmacology and Center for Neuroscience, Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, WV, USA; Center for Neuroscience Discovery, University of North Texas Health Science Center, Fort Worth, TX 76107, USA.
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Gravielle MC. Activation-induced regulation of GABAA receptors: Is there a link with the molecular basis of benzodiazepine tolerance? Pharmacol Res 2015; 109:92-100. [PMID: 26733466 DOI: 10.1016/j.phrs.2015.12.030] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Revised: 12/21/2015] [Accepted: 12/22/2015] [Indexed: 12/01/2022]
Abstract
Benzodiazepines have been used clinically for more than 50 years to treat disorders such as insomnia, anxiety, and epilepsy, as well as to aid muscle relaxation and anesthesia. The therapeutic index for benzodiazepines if very high and the toxicity is low. However, their usefulness is limited by the development of either or both tolerance to most of their pharmacological actions and dependence. Tolerance develops at different rates depending on the pharmacological action, suggesting the existence of distinct mechanisms for each behavioral parameter. Alternatively, multiple mechanisms could coexist depending on the subtype of GABAA receptor expressed and the brain region involved. Because most of the pharmacological actions of benzodiazepines are mediated through GABAA receptor binding, adaptive alterations in the number, structure, and/or functions of these receptors may play an important role in the development of tolerance. This review is focused on the regulation of GABAA receptors induced by long-term benzodiazepine exposure and its relationship with the development of tolerance. Understanding the mechanisms behind benzodiazepine tolerance is critical for designing drugs that could maintain their efficacy during long-term treatments.
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Affiliation(s)
- María Clara Gravielle
- Instituto de Investigaciones Farmacológicas, Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad de Buenos Aires, Junín 956, C1113AAD Buenos Aires, Argentina.
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Talarek S, Orzelska-Gorka J, Listos J, Serefko A, Poleszak E, Fidecka S. Effects of NMDA antagonists on the development and expression of tolerance to diazepam-induced motor impairment in mice. Pharmacol Biochem Behav 2015; 142:42-7. [PMID: 26723839 DOI: 10.1016/j.pbb.2015.12.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Revised: 12/07/2015] [Accepted: 12/21/2015] [Indexed: 11/19/2022]
Abstract
The goal of the study was to investigate the effects of ketamine and memantine on the development and expression of tolerance to diazepam (DZ)-induced motor impairment in mice. DZ-induced motor incoordination was assessed by the rotarod and chimney tests. It was found that (a) ketamine, at the dose of 5mg/kg (but not 2.5mg/kg), decreased the expression, but not the development, of tolerance to the motor impairing effects of DZ, (b) memantine, at the doses of 5 and 10mg/kg decreased both the development and expression of DZ tolerance in the rotarod test (also in the chimney test but at the higher dose of 10mg/kg) and (c) ketamine and memantine alone had no effect, either in the rotarod or the chimney test in mice. Those findings provided behavioral evidence that the glutamatergic system could contribute an important role in the development and/or expression of tolerance to DZ in mice.
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Affiliation(s)
- Sylwia Talarek
- Department of Pharmacology and Pharmacodynamics, Medical University of Lublin, Chodzki 4A, 20-093 Lublin, Poland.
| | - Jolanta Orzelska-Gorka
- Department of Pharmacology and Pharmacodynamics, Medical University of Lublin, Chodzki 4A, 20-093 Lublin, Poland
| | - Joanna Listos
- Department of Pharmacology and Pharmacodynamics, Medical University of Lublin, Chodzki 4A, 20-093 Lublin, Poland
| | - Anna Serefko
- Department of Applied Pharmacy, Medical University of Lublin, Chodzki 4A, 20-093 Lublin, Poland
| | - Ewa Poleszak
- Department of Applied Pharmacy, Medical University of Lublin, Chodzki 4A, 20-093 Lublin, Poland
| | - Sylwia Fidecka
- Department of Pharmacology and Pharmacodynamics, Medical University of Lublin, Chodzki 4A, 20-093 Lublin, Poland
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Tolerance to the sedative and anxiolytic effects of diazepam is associated with different alterations of GABAA receptors in rat cerebral cortex. Neuroscience 2015; 310:152-62. [DOI: 10.1016/j.neuroscience.2015.09.038] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Revised: 09/11/2015] [Accepted: 09/12/2015] [Indexed: 11/18/2022]
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Korpi ER, den Hollander B, Farooq U, Vashchinkina E, Rajkumar R, Nutt DJ, Hyytiä P, Dawe GS. Mechanisms of Action and Persistent Neuroplasticity by Drugs of Abuse. Pharmacol Rev 2015; 67:872-1004. [DOI: 10.1124/pr.115.010967] [Citation(s) in RCA: 101] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
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Crestani F, Rudolph U. Behavioral functions of GABAA receptor subtypes--the Zurich experience. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2014; 72:37-51. [PMID: 25600366 DOI: 10.1016/bs.apha.2014.10.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
GABAA receptors are the major inhibitory neurotransmitter receptors in the brain. They are heteropentamers that are typically classified according to their α subunits. By rendering each of the benzodiazepine-sensitive α subunits (α1, α2, α3, and α5) insensitive to modulation by classical benzodiazepines by His to Arg point mutations in knock-in mice, we were able to identify behavioral functions mediated by different GABAA receptor subtypes, which led to the development of novel therapeutic strategies. In this chapter, we provide a largely chronological overview on behavioral studies on GABAA receptor mutant mice at the Institute of Pharmacology and Toxicology at the University of Zurich.
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Affiliation(s)
- Florence Crestani
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
| | - Uwe Rudolph
- Laboratory of Genetic Neuropharmacology, McLean Hospital, Belmont, Massachusetts, USA; Department of Psychiatry, Harvard Medical School, Boston, Massachusetts, USA.
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Vashchinkina E, Panhelainen A, Aitta-Aho T, Korpi ER. GABAA receptor drugs and neuronal plasticity in reward and aversion: focus on the ventral tegmental area. Front Pharmacol 2014; 5:256. [PMID: 25505414 PMCID: PMC4243505 DOI: 10.3389/fphar.2014.00256] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Accepted: 11/03/2014] [Indexed: 12/13/2022] Open
Abstract
GABAA receptors are the main fast inhibitory neurotransmitter receptors in the mammalian brain, and targets for many clinically important drugs widely used in the treatment of anxiety disorders, insomnia and in anesthesia. Nonetheless, there are significant risks associated with the long-term use of these drugs particularly related to development of tolerance and addiction. Addictive mechanisms of GABAA receptor drugs are poorly known, but recent findings suggest that those drugs may induce aberrant neuroadaptations in the brain reward circuitry. Recently, benzodiazepines, acting on synaptic GABAA receptors, and modulators of extrasynaptic GABAA receptors (THIP and neurosteroids) have been found to induce plasticity in the ventral tegmental area (VTA) dopamine neurons and their main target projections. Furthermore, depending whether synaptic or extrasynaptic GABAA receptor populations are activated, the behavioral outcome of repeated administration seems to correlate with rewarding or aversive behavioral responses, respectively. The VTA dopamine neurons project to forebrain centers such as the nucleus accumbens and medial prefrontal cortex, and receive afferent projections from these brain regions and especially from the extended amygdala and lateral habenula, forming the major part of the reward and aversion circuitry. Both synaptic and extrasynaptic GABAA drugs inhibit the VTA GABAergic interneurons, thus activating the VTA DA neurons by disinhibition and this way inducing glutamatergic synaptic plasticity. However, the GABAA drugs failed to alter synaptic spine numbers as studied from Golgi-Cox-stained VTA dendrites. Since the GABAergic drugs are known to depress the brain metabolism and gene expression, their likely way of inducing neuroplasticity in mature neurons is by disinhibiting the principal neurons, which remains to be rigorously tested for a number of clinically important anxiolytics, sedatives and anesthetics in different parts of the circuitry.
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Affiliation(s)
- Elena Vashchinkina
- Department of Pharmacology, Institute of Biomedicine, University of Helsinki Helsinki, Finland
| | - Anne Panhelainen
- Institute of Biotechnology, University of Helsinki Helsinki, Finland
| | - Teemu Aitta-Aho
- Department of Pharmacology, Institute of Biomedicine, University of Helsinki Helsinki, Finland ; Department of Pharmacology, University of Cambridge Cambridge, UK
| | - Esa R Korpi
- Department of Pharmacology, Institute of Biomedicine, University of Helsinki Helsinki, Finland ; Department of Pharmacology, Yong Loo Lin School of Medicine, National University Health System, Neurobiology and Ageing Programme, Life Sciences Institute, National University of Singapore, and SINAPSE, Singapore Institute for Neurotechnology Singapore, Singapore
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Sengupta S, Weeraratne SD, Cho YJ, Pomeroy SL. Could α5-GABA-A receptor activation be used as a target for managing medulloblastomas? CNS Oncol 2014; 3:245-7. [PMID: 25286034 DOI: 10.2217/cns.14.27] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Affiliation(s)
- Soma Sengupta
- Department of Neurology, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA
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ABHD6 blockade exerts antiepileptic activity in PTZ-induced seizures and in spontaneous seizures in R6/2 mice. Neuron 2014; 83:361-371. [PMID: 25033180 DOI: 10.1016/j.neuron.2014.06.030] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/24/2014] [Indexed: 12/17/2022]
Abstract
The serine hydrolase α/β-hydrolase domain 6 (ABHD6) hydrolyzes the most abundant endocannabinoid (eCB) in the brain, 2-arachidonoylglycerol (2-AG), and controls its availability at cannabinoid receptors. We show that ABHD6 inhibition decreases pentylenetetrazole (PTZ)-induced generalized tonic-clonic and myoclonic seizure incidence and severity. This effect is retained in Cnr1(-/-) or Cnr2(-/-) mice, but blocked by addition of a subconvulsive dose of picrotoxin, suggesting the involvement of GABAA receptors. ABHD6 inhibition also blocked spontaneous seizures in R6/2 mice, a genetic model of juvenile Huntington's disease known to exhibit dysregulated eCB signaling. ABHD6 blockade retained its antiepileptic activity over chronic dosing and was not associated with psychomotor or cognitive effects. While the etiology of seizures in R6/2 mice remains unsolved, involvement of the hippocampus is suggested by interictal epileptic discharges, increased expression of vGLUT1 but not vGAT, and reduced Neuropeptide Y (NPY) expression. We conclude that ABHD6 inhibition may represent a novel antiepileptic strategy.
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Hodges LM, Fyer AJ, Weissman MM, Logue MW, Haghighi F, Evgrafov O, Rotondo A, Knowles JA, Hamilton SP. Evidence for linkage and association of GABRB3 and GABRA5 to panic disorder. Neuropsychopharmacology 2014; 39:2423-31. [PMID: 24755890 PMCID: PMC4138754 DOI: 10.1038/npp.2014.92] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2013] [Revised: 02/23/2014] [Accepted: 02/24/2014] [Indexed: 01/04/2023]
Abstract
Panic disorder (PD) is a debilitating anxiety disorder characterized by episodes of intense fear with autonomic and psychological symptoms that lead to behavioral impairment. A convergence of genetic and biological evidence implicates gamma-aminobutyric acid type A receptor subunits on chromosome 15q12 as candidate genes for PD. This study investigated 120 Caucasian, multiplex PD pedigrees using regional microsatellites (chr15q11-13) and found support for linkage (logarithm of odds (LOD) ⩾2), with a prominent parent-of-origin effect. Genotyping with 10 single-nucleotide polymorphisms (SNPs) showed linkage to GABRB3 (rs11631421, LOD=4.6) and GABRA5 (rs2075716, LOD=2.2), and allelic association to GABRB3 (rs8024564, p=0.005; rs8025575, p=0.02) and GABRA5 (rs35399885, p=0.05). Genotyping of an independent Sardinian PD trio sample also supported association in the region, again with a parent-of-origin effect. These findings provide genetic evidence for the involvement of the genes GABRB3 and GABRA5 in the susceptibility to PD.
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Affiliation(s)
- Laura M Hodges
- Department of Psychiatry and Institute for Human Genetics, University of California, San Francisco, CA, USA
| | - Abby J Fyer
- Department of Psychiatry, Columbia University College of Physicians and Surgeons and the New York State Psychiatric Institute, New York, NY, USA,Department of Psychiatry, Columbia University College of Physicians and Surgeons and the New York State Psychiatric Institute, 1050 Riverside Drive, Unit 82, New York, NY 10032, USA, Tel: +1 212 543 5372, Fax: +1 212 543 6609, E-mail:
| | - Myrna M Weissman
- Department of Psychiatry, Columbia University College of Physicians and Surgeons and the New York State Psychiatric Institute, New York, NY, USA
| | - Mark W Logue
- Biomedical Genetics, Department of Medicine, Boston University School of Medicine, Boston, MA, USA
| | - Fatemeh Haghighi
- Department of Psychiatry, Icahn School of Medicine, New York, NY, USA
| | - Oleg Evgrafov
- Department of Psychiatry and Behavioral Sciences, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | | | - James A Knowles
- Department of Psychiatry and Behavioral Sciences, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Steven P Hamilton
- Department of Psychiatry and Institute for Human Genetics, University of California, San Francisco, CA, USA,Department of Psychiatry, Kaiser Permanente Medical Center, San Francisco, CA, USA,Department of Psychiatry, Kaiser Permanente Medical Center, 4141 Geary Boulevard, 3rd Floor, San Francisco, CA 94118, USA, Tel: +1 415 833 2034, Fax: +1 415 833 2034, E-mail:
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Wright BT, Gluszek CF, Heldt SA. The effects of repeated zolpidem treatment on tolerance, withdrawal-like symptoms, and GABAA receptor mRNAs profile expression in mice: comparison with diazepam. Psychopharmacology (Berl) 2014; 231:2967-79. [PMID: 24531568 DOI: 10.1007/s00213-014-3473-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Accepted: 01/26/2014] [Indexed: 10/25/2022]
Abstract
RATIONALE Zolpidem is a short-acting, non-benzodiazepine hypnotic that acts as a full agonist at α1-containing GABAA receptors. Overall, zolpidem purportedly has fewer instances of abuse and dependence than traditionally used benzodiazepines. However, several studies have shown that zolpidem may be more similar to benzodiazepines in terms of behavioral tolerance and withdrawal symptoms. OBJECTIVES In the current study, we examined whether subchronic zolpidem or diazepam administration produced deficits in zolpidem's locomotor-impairing effects, anxiety-like behaviors, and changes in GABAAR subunit messenger RNA (mRNA). METHODS Mice were given subchronic injections of either zolpidem (10 mg/kg), diazepam (20 mg/kg), or vehicle twice daily for 7 days. On day 8, mice were given a challenge dose of zolpidem (2 mg/kg) or vehicle before open field testing. Another set of mice underwent the same injection regimen but were sacrificed on day 8 for qRT-PCR analysis. RESULTS We found that subchronic zolpidem and diazepam administration produced deficits in the acute locomotor-impairing effects of zolpidem and increased anxiety-like behaviors 1 day after drug termination. In addition, we found that subchronic treatment of zolpidem and diazepam induced distinct but overlapping GABAAR subunit mRNA changes in the cortex but few changes in the hippocampus, amygdala, or prefrontal cortex. Levels of mRNA measured in separate mice after a single injection of either zolpidem or diazepam revealed no mRNA changes. CONCLUSIONS In mice, subchronic treatment of zolpidem and diazepam can produce deficits in the locomotor-impairing effects of zolpidem, anxiety-like withdrawal symptoms, and subunit-specific mRNA changes.
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Affiliation(s)
- Brittany T Wright
- The Department of Anatomy and Neurobiology, Neuroscience Institute, University of Tennessee Health Science Center, 855 Monroe Ave, Memphis, TN, 38163, USA
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Ennaceur A. Tests of unconditioned anxiety - pitfalls and disappointments. Physiol Behav 2014; 135:55-71. [PMID: 24910138 DOI: 10.1016/j.physbeh.2014.05.032] [Citation(s) in RCA: 149] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Revised: 04/21/2014] [Accepted: 05/28/2014] [Indexed: 02/05/2023]
Abstract
The plus-maze, the light-dark box and the open-field are the main current tests of unconditioned anxiety for mice and rats. Despite their disappointing achievements, they remain as popular as ever and seem to play an important role in an ever-growing demand for behavioral phenotyping and drug screening. Numerous reviews have repeatedly reported their lack of consistency and reliability but they failed to address the core question of whether these tests do provide unequivocal measures of fear-induced anxiety, that these measurements are not confused with measures of fear-induced avoidance or natural preference responses - i.e. discriminant validity. In the present report, I examined numerous issues that undermine the validity of the current tests, and I highlighted various flaws in the aspects of these tests and the methodologies pursued. This report concludes that the evidence in support of the validity of the plus-maze, the light/dark box and the open-field as anxiety tests is poor and methodologically questionable.
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Affiliation(s)
- A Ennaceur
- University of Sunderland, Department of Pharmacy, Wharncliffe Street, Sunderland SR1 3SD, UK.
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Yoshimura RF, Tran MB, Hogenkamp DJ, Johnstone TB, Xie JY, Porreca F, Gee KW. Limited central side effects of a β-subunit subtype-selective GABAA receptor allosteric modulator. J Psychopharmacol 2014; 28:472-8. [PMID: 24108410 DOI: 10.1177/0269881113507643] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
GABAergic anxiolytics have well-documented centrally mediated side effects including sedation, potentiation of ethanol, tolerance, abuse liability and memory impairment. Most research directed towards identifying an anxioselective GABAergic therapeutic has been based upon the theory that these side effects could be mitigated by avoiding α1/5-subunit GABAA receptors while specifically targeting those with the α2/3-subunit. Unfortunately, there are prominent exceptions to this theory and it has yet to be translated into clinical success. We previously demonstrated that β2/3-subunit-selective GABAA receptor-positive allosteric modulators act as anxiolytics with reduced sedation and ethanol potentiation regardless of their activity at α1-subunit GABAA receptors. The prototypical β2/3-subunit-selective positive allosteric modulator, 2-261, is further characterized here for additional side effects commonly associated with central GABAA receptor activation. In mice, 10 times the anxiolytic dose (10 mg/kg) of 2-261 does not induce behavioral tolerance in the elevated plus maze following a 2 week subchronic treatment. In rats, an anxiolytic dose (10 mg/kg) of 2-261 is inactive in conditioned place preference, suggesting a reduced abuse liability. In rats, 10 times the anxiolytic dose (100 mg/kg) of 2-261 does not have a significant amnestic effect in the radial arm maze, suggesting a greater therapeutic index for memory impairment. These results suggest that β2/3-subunit subtype-selective GABAA receptor-positive allosteric modulators not only have reduced sedative liability, but also a reduction in other central side effects commonly associated with broader GABAA receptor activation. β2/3-subunit-selective compounds may represent a novel design template for anxiolytics with benzodiazepine-like efficacy and mitigated side effects.
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Affiliation(s)
- Ryan F Yoshimura
- 1Department of Pharmacology, School of Medicine, University of California, Irvine, Irvine, CA, USA
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The behavioral pharmacology of zolpidem: evidence for the functional significance of α1-containing GABA(A) receptors. Psychopharmacology (Berl) 2014; 231:1865-96. [PMID: 24563183 DOI: 10.1007/s00213-014-3457-x] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Accepted: 01/11/2014] [Indexed: 10/25/2022]
Abstract
RATIONALE Zolpidem is a positive allosteric modulator of γ-aminobutyric acid (GABA) with preferential binding affinity and efficacy for α1-subunit containing GABA(A) receptors (α1-GABA(A)Rs). Over the last three decades, a variety of animal models and experimental procedures have been used in an attempt to relate the behavioral profile of zolpidem and classic benzodiazepines (BZs) to their interaction with α1-GABA(A)Rs. OBJECTIVES This paper reviews the results of rodent and non-human primate studies that have evaluated the effects of zolpidem on motor behaviors, anxiety, memory, food and fluid intake, and electroencephalogram (EEG) sleep patterns. Also included are studies that examined zolpidem's discriminative, reinforcing, and anticonvulsant effects as well as behavioral signs of tolerance and withdrawal. RESULTS The literature reviewed indicates that α1-GABA(A)Rs play a principle role in mediating the hypothermic, ataxic-like, locomotor- and memory-impairing effects of zolpidem and BZs. Evidence also suggests that α1-GABA(A)Rs play partial roles in the hypnotic, EEG sleep, anticonvulsant effects, and anxiolytic-like of zolpidem and diazepam. These studies also indicate that α1-GABA(A)Rs play a more prominent role in mediating the discriminative stimulus, reinforcing, hyperphagic, and withdrawal effects of zolpidem and BZs in primates than in rodents. CONCLUSIONS The psychopharmacological data from both rodents and non-human primates suggest that zolpidem has a unique pharmacological profile when compared with classic BZs. The literature reviewed here provides an important framework for studying the role of different GABA(A)R subtypes in the behavioral effects of BZ-type drugs and helps guide the development of new pharmaceutical agents for disorders currently treated with BZ-type drugs.
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Smith SG, Sanchez R, Zhou MM. Privileged diazepine compounds and their emergence as bromodomain inhibitors. ACTA ACUST UNITED AC 2014; 21:573-83. [PMID: 24746559 DOI: 10.1016/j.chembiol.2014.03.004] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Revised: 03/02/2014] [Accepted: 03/15/2014] [Indexed: 12/23/2022]
Abstract
Chemical compounds built on a diazepine scaffold have recently emerged as potent inhibitors of the acetyl-lysine binding activity of bromodomain-containing proteins, which is required for gene transcriptional activation in cancer and inflammation. Not only have these chemical compounds validated bromodomains as attractive epigenetic drug targets, but they have also brought to the forefront another application of the diazepine, which had already been regarded as a versatile chemical scaffold in rational drug design. This article reviews the success of diazepine compounds as therapeutic agents and examines the unique chemical and geometric features of this privileged scaffold that make it an excellent template for developing potent and selective molecules that control bromodomain-related gene expression in human diseases.
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Affiliation(s)
- Steven G Smith
- Department of Structural and Chemical Biology, Icahn School of Medicine at Mount Sinai, 1425 Madison Avenue, New York, NY 10029, USA
| | - Roberto Sanchez
- Department of Structural and Chemical Biology, Icahn School of Medicine at Mount Sinai, 1425 Madison Avenue, New York, NY 10029, USA
| | - Ming-Ming Zhou
- Department of Structural and Chemical Biology, Icahn School of Medicine at Mount Sinai, 1425 Madison Avenue, New York, NY 10029, USA.
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Gutiérrez ML, Ferreri MC, Farb DH, Gravielle MC. GABA-induced uncoupling of GABA/benzodiazepine site interactions is associated with increased phosphorylation of the GABAA receptor. J Neurosci Res 2014; 92:1054-61. [PMID: 24723313 DOI: 10.1002/jnr.23387] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2013] [Revised: 02/14/2014] [Accepted: 02/26/2014] [Indexed: 11/08/2022]
Abstract
The use-dependent regulation of the GABAA receptor occurs under physiological, pathological, and pharmacological conditions. Tolerance induced by prolonged administration of benzodiazepines is associated with changes in GABAA receptor function. Chronic exposure of neurons to GABA for 48 hr induces a downregulation of the GABAA receptor number and an uncoupling of the GABA/benzodiazepine site interactions. A single brief exposure ((t1/2) = 3 min) of rat neocortical neurons to the neurotransmitter initiates a process that results in uncoupling hours later (t(1/2) = 12 hr) without alterations in the number of GABAA receptors and provides a paradigm to study the uncoupling mechanism selectively. Here we report that uncoupling induced by a brief GABAA receptor activation is blocked by the coincubation with inhibitors of protein kinases A and C, indicating that the uncoupling is mediated by the activation of a phosphorylation cascade. GABA-induced uncoupling is accompanied by subunit-selective changes in the GABAA receptor mRNA levels. However, the GABA-induced downregulation of the α3 subunit mRNA level is not altered by the kinase inhibitors, suggesting that the uncoupling is the result of a posttranscriptional regulatory process. GABA exposure also produces an increase in the serine phosphorylation on the GABAA receptor γ2 subunit. Taken together, our results suggest that the GABA-induced uncoupling is mediated by a posttranscriptional mechanism involving an increase in the phosphorylation of GABAA receptors. The uncoupling of the GABAA receptor may represent a compensatory mechanism to control GABAergic neurotransmission under conditions in which receptors are persistently activated.
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Affiliation(s)
- María L Gutiérrez
- Instituto de Investigaciones Farmacológicas, Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad de Buenos Aires, Buenos Aires, Argentina
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Sengupta S, Weeraratne SD, Sun H, Phallen J, Rallapalli SK, Teider N, Kosaras B, Amani V, Pierre-Francois J, Tang Y, Nguyen B, Yu F, Schubert S, Balansay B, Mathios D, Lechpammer M, Archer TC, Tran P, Reimer RJ, Cook JM, Lim M, Jensen FE, Pomeroy SL, Cho YJ. α5-GABAA receptors negatively regulate MYC-amplified medulloblastoma growth. Acta Neuropathol 2014; 127:593-603. [PMID: 24196163 DOI: 10.1007/s00401-013-1205-7] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Accepted: 10/28/2013] [Indexed: 11/25/2022]
Abstract
Neural tumors often express neurotransmitter receptors as markers of their developmental lineage. Although these receptors have been well characterized in electrophysiological, developmental and pharmacological settings, their importance in the maintenance and progression of brain tumors and, importantly, the effect of their targeting in brain cancers remains obscure. Here, we demonstrate high levels of GABRA5, which encodes the α5-subunit of the GABAA receptor complex, in aggressive MYC-driven, "Group 3" medulloblastomas. We hypothesized that modulation of α5-GABAA receptors alters medulloblastoma cell survival and monitored biological and electrophysiological responses of GABRA5-expressing medulloblastoma cells upon pharmacological targeting of the GABAA receptor. While antagonists, inverse agonists and non-specific positive allosteric modulators had limited effects on medulloblastoma cells, a highly specific and potent α5-GABAA receptor agonist, QHii066, resulted in marked membrane depolarization and a significant decrease in cell survival. This effect was GABRA5 dependent and mediated through the induction of apoptosis as well as accumulation of cells in S and G2 phases of the cell cycle. Chemical genomic profiling of QHii066-treated medulloblastoma cells confirmed inhibition of MYC-related transcriptional activity and revealed an enrichment of HOXA5 target gene expression. siRNA-mediated knockdown of HOXA5 markedly blunted the response of medulloblastoma cells to QHii066. Furthermore, QHii066 sensitized GABRA5 positive medulloblastoma cells to radiation and chemotherapy consistent with the role of HOXA5 in directly regulating p53 expression and inducing apoptosis. Thus, our results provide novel insights into the synthetic lethal nature of α5-GABAA receptor activation in MYC-driven/Group 3 medulloblastomas and propose its targeting as a novel strategy for the management of this highly aggressive tumor.
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Affiliation(s)
- Soma Sengupta
- Department of Neurology, Boston Children's Hospital, Boston, MA, USA
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48
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Fritschy JM, Panzanelli P. GABAAreceptors and plasticity of inhibitory neurotransmission in the central nervous system. Eur J Neurosci 2014; 39:1845-65. [DOI: 10.1111/ejn.12534] [Citation(s) in RCA: 144] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2014] [Revised: 01/29/2014] [Accepted: 01/29/2014] [Indexed: 12/11/2022]
Affiliation(s)
- Jean-Marc Fritschy
- Institute of Pharmacology and Toxicology; University of Zurich; Winterthurerstrasse 190 8057 Zurich Switzerland
- Neuroscience Center Zurich; University of Zurich and ETH; Zurich Switzerland
| | - Patrizia Panzanelli
- Department of Neuroscience Rita Levi Montalcini; University of Turin; Turin Italy
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Jensen HS, Nichol K, Lee D, Ebert B. Clobazam and its active metabolite N-desmethylclobazam display significantly greater affinities for α₂- versus α₁-GABA(A)-receptor complexes. PLoS One 2014; 9:e88456. [PMID: 24533090 PMCID: PMC3922815 DOI: 10.1371/journal.pone.0088456] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Accepted: 01/07/2014] [Indexed: 01/09/2023] Open
Abstract
Clobazam (CLB), a 1,5-benzodiazepine (BZD), was FDA-approved in October 2011 for the adjunctive treatment of seizures associated with Lennox-Gastaut syndrome (LGS) in patients 2 years and older. BZDs exert various CNS effects through allosteric modulation of GABAA receptors. The structurally distinct, 1,4-BZD clonazepam (CLN) is also approved to treat LGS. The precise mechanisms of action and clinical efficacy of both are unknown. Data show that the GABAA α1-subunit–selective compound zolpidem [ZOL] exhibits hypnotic/sedative effects. Conversely, data from knock-in mice carrying BZD binding site mutations suggest that the α2 subunit mediates anticonvulsant effects, without sedative actions. Hence, the specific pattern of interactions across the GABAA receptor complexes of BZDs might be reflected in their clinical efficacies and adverse effect profiles. In this study, GABAA-receptor binding affinities of CLB, N-desmethylclobazam (N-CLB, the major metabolite of CLB), CLN, and ZOL were characterized with native receptors from rat-brain homogenates and on cloned receptors from HEK293 cells transfected with combinations of α (α1, α2, α3, or α5), β2, and γ2 subtypes. Our results demonstrate that CLB and N-CLB have significantly greater binding affinities for α2- vs. α1-receptor complexes, a difference not observed for CLN, for which no distinction between α2 and α1 receptors was observed. Our experiments with ZOL confirmed the high preference for α1 receptors. These results provide potential clues to a new understanding of the pharmacologic modes of action of CLB and N-CLB.
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Affiliation(s)
- Henrik Sindal Jensen
- Synaptic Transmission, Neuroscience Drug Discovery, H. Lundbeck A/S, Valby, Denmark
- * E-mail:
| | - Kathryn Nichol
- Medical Affairs, Lundbeck LLC, Deerfield, Illinois, United States of America
| | - Deborah Lee
- Clinical Affairs, Lundbeck LLC, Deerfield, Illinois, United States of America
| | - Bjarke Ebert
- Department of Electrophysiology, H. Lundbeck A/S, Valby, Denmark
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50
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Licata SC, Shinday NM, Huizenga MN, Darnell SB, Sangrey GR, Rudolph U, Rowlett JK, Sadri-Vakili G. Alterations in brain-derived neurotrophic factor in the mouse hippocampus following acute but not repeated benzodiazepine treatment. PLoS One 2013; 8:e84806. [PMID: 24367698 PMCID: PMC3868703 DOI: 10.1371/journal.pone.0084806] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Accepted: 11/19/2013] [Indexed: 12/24/2022] Open
Abstract
Benzodiazepines (BZs) are safe drugs for treating anxiety, sleep, and seizure disorders, but their use also results in unwanted effects including memory impairment, abuse, and dependence. The present study aimed to reveal the molecular mechanisms that may contribute to the effects of BZs in the hippocampus (HIP), an area involved in drug-related plasticity, by investigating the regulation of immediate early genes following BZ administration. Previous studies have demonstrated that both brain derived neurotrophic factor (BDNF) and c-Fos contribute to memory- and abuse-related processes that occur within the HIP, and their expression is altered in response to BZ exposure. In the current study, mice received acute or repeated administration of BZs and HIP tissue was analyzed for alterations in BDNF and c-Fos expression. Although no significant changes in BDNF or c-Fos were observed in response to twice-daily intraperitoneal (i.p.) injections of diazepam (10 mg/kg + 5 mg/kg) or zolpidem (ZP; 2.5 mg/kg + 2.5 mg/kg), acute i.p. administration of both triazolam (0.03 mg/kg) and ZP (1.0 mg/kg) decreased BDNF protein levels within the HIP relative to vehicle, without any effect on c-Fos. ZP specifically reduced exon IV-containing BDNF transcripts with a concomitant increase in the association of methyl-CpG binding protein 2 (MeCP2) with BDNF promoter IV, suggesting that MeCP2 activity at this promoter may represent a ZP-specific mechanism for reducing BDNF expression. ZP also increased the association of phosphorylated cAMP response element binding protein (pCREB) with BDNF promoter I. Future work should examine the interaction between ZP and DNA as the cause for altered gene expression in the HIP, given that BZs can enter the nucleus and intercalate into DNA directly.
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Affiliation(s)
- Stephanie C. Licata
- McLean Hospital, Belmont, Massachusetts, United States of America
- Harvard Medical School, Boston, Massachusetts, United States of America
| | - Nina M. Shinday
- New England Primate Research Center, Southborough, Massachusetts, United States of America
- Harvard Medical School, Boston, Massachusetts, United States of America
| | - Megan N. Huizenga
- Massachusetts General Hospital, Charlestown, Massachusetts, United States of America
- Harvard Medical School, Boston, Massachusetts, United States of America
| | - Shayna B. Darnell
- Massachusetts General Hospital, Charlestown, Massachusetts, United States of America
- Harvard Medical School, Boston, Massachusetts, United States of America
| | - Gavin R. Sangrey
- Massachusetts General Hospital, Charlestown, Massachusetts, United States of America
- Harvard Medical School, Boston, Massachusetts, United States of America
| | - Uwe Rudolph
- McLean Hospital, Belmont, Massachusetts, United States of America
- Harvard Medical School, Boston, Massachusetts, United States of America
| | - James K. Rowlett
- New England Primate Research Center, Southborough, Massachusetts, United States of America
- Harvard Medical School, Boston, Massachusetts, United States of America
| | - Ghazaleh Sadri-Vakili
- Massachusetts General Hospital, Charlestown, Massachusetts, United States of America
- Harvard Medical School, Boston, Massachusetts, United States of America
- *
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