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Greene SL, Syrjanen R, Hodgson SE, Abouchedid R, Schumann J. Co-exposure to gamma-hydroxybutyrate is associated with attenuated neuropsychiatric and stimulant effects of metamfetamine. Clin Toxicol (Phila) 2024; 62:303-313. [PMID: 38884342 DOI: 10.1080/15563650.2024.2353265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Accepted: 05/03/2024] [Indexed: 06/18/2024]
Abstract
INTRODUCTION Acute metamfetamine toxicity is characterized by stimulant effects and neuropsychiatric disturbance, which is attenuated by gamma-aminobutyric acid type A receptor agonists including benzodiazepines. We utilized clinical registry data to examine the effect of co-exposure to a gamma-aminobutyric acid type B receptor agonist (gamma-hydroxybutyrate) in illicit drug cases with analytically confirmed exposure to metamfetamine. METHODS The Emerging Drugs Network of Australia Victoria is an ethics board-approved prospective registry collecting clinical and analytical data (utilising blood samples) on emergency department illicit drug presentations. Comparison groups were defined by analytically confirmed exposure: lone metamfetamine, metamfetamine plus gamma-hydroxybutyrate, metamfetamine plus benzodiazepine, metamfetamine plus gamma-hydroxybutyrate plus benzodiazepine. Cases with co-exposure to other stimulants or sedatives were excluded. RESULTS Median metamfetamine blood concentrations were significantly greater in metamfetamine plus gamma-hydroxybutyrate (n = 153, median = 0.20 mg/L, interquartile range: 0.10-0.32 mg/L, 95 per cent confidence interval: 0.20-0.23 mg/L) and metamfetamine plus gamma-hydroxybutyrate plus benzodiazepine (n = 160, median = 0.20 mg/L, interquartile range: 0.10-0.30 mg/L, 95 per cent confidence interval: 0.20-0.30 mg/L) positive groups compared to gamma-hydroxybutyrate negative groups including metamfetamine (n = 81, median = 0.10 mg/L, interquartile range: 0.05-0.21 mg/L, 95 per cent confidence interval: 0.09-0.18 mg/L) and metamfetamine plus benzodiazepine (n = 73, median = 0.10 mg/L, interquartile range: 0.06-0.20 mg/L, 95 per cent confidence interval: 0.09-0.20 mg/L) groups (P < 0.0004). Presenting heart rate in metamfetamine plus gamma-hydroxybutyrate cases (n = 153, median = 72 beats per minute, interquartile range: 63-86 beats per minute, 95 per cent confidence interval: 70-78 beats per minute) was significantly lower than metamfetamine plus benzodiazepine cases (n = 73, median = 84 beats per minute, interquartile range: 73-98 beats per minute, 95 per cent confidence interval: 80-90 beats per minute, P < 0.0001), and lone metamfetamine cases (n = 81, median = 110 beats per minute, interquartile range: 87-131 beats per minute, 95 per cent confidence interval: 93-120 beats per minute, P < 0.0001). Presenting temperature in metamfetamine plus gamma-hydroxybutyrate cases (median = 35.8 °C, interquartile range: 35.0-36.2 °C, 95 per cent confidence interval 35.6-35.9 °C) was significantly lower than metamfetamine plus benzodiazepine cases (median 36.2 °C, interquartile range 35.7-36.6 °C, 95 per cent confidence interval, 36.0-36.4 °C, P = 0.017), and lone metamfetamine cases (median = 36.5 °C, interquartile range: 35.8-37.1 °C, 95 per cent confidence interval: 36.2-36.7 °C, P < 0.0001). Median presenting systolic blood pressure was significantly (P ≤ 0.001) lower in benzodiazepine positive groups (metamfetamine plus benzodiazepine median = 120 mmHg, interquartile range: 109-132 mmHg, 95 per cent confidence interval: 116-124 mmHg and metamfetamine plus benzodiazepine plus gamma-hydroxybutyrate median = 124 mmHg, interquartile range: 110-137 mmHg, 95 per cent confidence interval: 120-129 mmHg). Incidence of sedation (Glasgow Coma Scale less than 9) was significantly greater in metamfetamine plus gamma-hydroxybutyrate cases (63 per cent) compared to metamfetamine plus benzodiazepine cases (27 per cent, P < 0.0001) and lone metamfetamine cases (15 per cent, P < 0.0001). Incidence of agitation was significantly lower in metamfetamine plus gamma-hydroxybutyrate plus benzodiazepine cases (17 per cent, P < 0.0001) and metamfetamine plus gamma-hydroxybutyrate cases (34 per cent, P = 0.0004) compared to lone metamfetamine cases (58 per cent). DISCUSSION Differences in gamma-aminobutyric acid type A and B receptor physiology may offer a gamma-aminobutyric acid type B agonist-facilitated alternative pharmacodynamic mechanism able to attenuate metamfetamine stimulant and neuropsychiatric toxicity. CONCLUSION Metamfetamine intoxicated patients with analytically confirmed co-exposure to gamma-hydroxybutyrate had significantly reduced heart rate, body temperature and incidence of agitation compared to patients with lone metamfetamine exposure. Metamfetamine intoxicated patients with analytically confirmed co-exposure to a benzodiazepine had significantly reduced systolic blood pressure compared to patients with lone metamfetamine exposure. We hypothesize that gamma-aminobutyric acid type B receptor agonists may be beneficial in the management of acute metamfetamine toxicity.
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Affiliation(s)
- Shaun Lawrence Greene
- Austin Health, Victorian Poisons Information Centre, Austin Hospital, Heidelberg, Victoria, Australia
- Austin Health, Emergency Department, Austin Hospital, Heidelberg, Victoria, Australia
- Melbourne Medical School, Department of Critical Care, The University of Melbourne, Parkville, Victoria, Australia
| | - Rebekka Syrjanen
- Austin Health, Emergency Department, Austin Hospital, Heidelberg, Victoria, Australia
- Department of Forensic Medicine, Monash University, Southbank, Victoria, Australia
| | - Sarah Ellen Hodgson
- Austin Health, Victorian Poisons Information Centre, Austin Hospital, Heidelberg, Victoria, Australia
- Austin Health, Emergency Department, Austin Hospital, Heidelberg, Victoria, Australia
| | - Rachelle Abouchedid
- Austin Health, Victorian Poisons Information Centre, Austin Hospital, Heidelberg, Victoria, Australia
- Bendigo Health, Emergency Department, Bendigo Hospital, Bendigo, Victoria, Australia
| | - Jennifer Schumann
- Department of Forensic Medicine, Monash University, Southbank, Victoria, Australia
- Toxicology Department, Victorian Institute of Forensic Medicine, Southbank, Victoria, Australia
- Monash Addiction Research Centre, Monash University, Frankston, Victoria, Australia
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Paterson LM, Barker D, Cro S, Mozgunov P, Phillips R, Smith C, Nahar L, Paterson S, Lingford-Hughes AR. FORWARDS-1: an adaptive, single-blind, placebo-controlled ascending dose study of acute baclofen on safety parameters in opioid dependence during methadone-maintenance treatment-a pharmacokinetic-pharmacodynamic study. Trials 2022; 23:880. [PMID: 36258248 PMCID: PMC9579625 DOI: 10.1186/s13063-022-06821-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Accepted: 10/05/2022] [Indexed: 11/17/2022] Open
Abstract
Background Treatment of opiate addiction with opiate substitution treatment (e.g. methadone) is beneficial. However, some individuals desire or would benefit from abstinence but there are limited options to attenuate problems with opiate withdrawal. Preclinical and preliminary clinical evidence suggests that the GABA-B agonist, baclofen, has the desired properties to facilitate opiate detoxification and prevent relapse. This study aims to understand whether there are any safety issues in administering baclofen to opioid-dependent individuals receiving methadone. Methods Opiate-dependent individuals (DSM-5 severe opioid use disorder) maintained on methadone will be recruited from addiction services in northwest London (NHS and third sector providers). Participants will be medically healthy with no severe chronic obstructive pulmonary disease or type 2 respiratory failure, no current dependence on other substances (excluding nicotine), no current severe DSM-5 psychiatric disorders, and no contraindications for baclofen or 4800 IU vitamin D (placebo). Eligible participants will be randomised in a 3:1 ratio to receive baclofen or placebo in an adaptive, single-blind, ascending dose design. A Bayesian dose-escalation model will inform the baclofen dose (10, 30, 60, or 90 mg) based on the incidence of ‘dose-limiting toxicity’ (DLT) events and participant-specific methadone dose. A range of respiratory, cardiovascular, and sedative measures including the National Early Warning Score (NEWS2) and Glasgow Coma Scale will determine DLT. On the experimental day, participants will consume their usual daily dose of methadone followed by an acute dose of baclofen or placebo (vitamin D3) ~ 1 h later. Measures including oxygen saturation, transcutaneous CO2, respiratory rate, QTc interval, subjective effects (sedation, drug liking, craving), plasma levels (baclofen, methadone), and adverse events will be obtained using validated questionnaires and examinations periodically for 5 h after dosing. Discussion Study outcomes will determine what dose of baclofen is safe to prescribe to those receiving methadone, to inform a subsequent proof-of-concept trial of the efficacy baclofen to facilitate opiate detoxification. To proceed, the minimum acceptable dose is 30 mg of baclofen in patients receiving ≤ 60 mg/day methadone based on the clinical experience of baclofen’s use in alcoholism and guidelines for the management of opiate dependence. Trial registration Clinicaltrials.gov NCT05161351. Registered on 16 December 2021. Supplementary Information The online version contains supplementary material available at 10.1186/s13063-022-06821-9.
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Affiliation(s)
- L M Paterson
- Division of Psychiatry, Department of Brain Sciences, Imperial College London, London, UK.
| | - D Barker
- Division of Psychiatry, Department of Brain Sciences, Imperial College London, London, UK
| | - S Cro
- Imperial Clinical Trials Unit, Imperial College London, London, UK
| | - P Mozgunov
- MRC Biostatistics Unit, University of Cambridge, Cambridge, UK
| | - R Phillips
- Imperial Clinical Trials Unit, Imperial College London, London, UK
| | - C Smith
- Imperial Clinical Trials Unit, Imperial College London, London, UK
| | - L Nahar
- Toxicology Unit, Imperial College London, London, UK
| | - S Paterson
- Toxicology Unit, Imperial College London, London, UK
| | - A R Lingford-Hughes
- Division of Psychiatry, Department of Brain Sciences, Imperial College London, London, UK
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Bareli T, Ahdoot HL, Ben Moshe H, Barnea R, Warhaftig G, Gispan I, Maayan R, Rosca P, Weizman A, Yadid G. Novel Opipramol-Baclofen Combination Alleviates Depression and Craving and Facilitates Recovery From Substance Use Disorder-An Animal Model and a Human Study. Front Behav Neurosci 2021; 15:788708. [PMID: 35002647 PMCID: PMC8733380 DOI: 10.3389/fnbeh.2021.788708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2021] [Accepted: 11/29/2021] [Indexed: 11/13/2022] Open
Abstract
Substance use disorders (SUDs) are associated with depression and anxiety, with the latter being one of the major factors in substance-seeking and relapse. Due to dose-dependent sedative side effects there is limited efficacy of baclofen treatment for SUDs. Here we suggest the use of a novel combination of opipramol and baclofen (O/B) which is known to attenuate anxiety and depression, for the facilitation of recovery from SUDs. Since both opipramol and baclofen have a common downstream signal transduction, their individual doses could be reduced while still maintaining the benefits of the combination. We tested the O/B combination in both animals and patients. Rats treated with O/B showed significant attenuation in craving behavior and in relapse rate during withdrawal from cocaine. In a double-blind, placebo-controlled pilot study, conducted in a residential detoxification center, 14 males and 3 females, aged 28-60 years were assigned to a study (n = 6) and a placebo (n = 11) group (placebo group: 40 ± 10.5 years; O/B group 40 ± 10.8 years). The participants completed scales measuring depression, anxiety and craving symptoms and provided saliva samples for stress hormone examination [cortisol and dehydroepiandrosterone-sulfate (DHEA-S)]. Participants with polysubstance use disorder (PsUD) treated with O/B showed a reduction in cravings and depression and an increase in DHEA-S and in the DHEA-S/cortisol ratio. Our findings indicate a beneficial effect of O/B treatment. This study suggests a novel candidate for pharmacological treatment of patients with SUD and comorbid mood/anxiety disorders that may facilitate their rehabilitation.
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Affiliation(s)
- Tzofnat Bareli
- Faculty of Life Sciences, Leslie and Gonda (Goldschmied) Multidisciplinary Brain Research Center, Bar Ilan University, Ramat Gan, Israel
| | - Hadas Levi Ahdoot
- Faculty of Life Sciences, Leslie and Gonda (Goldschmied) Multidisciplinary Brain Research Center, Bar Ilan University, Ramat Gan, Israel
| | - Hila Ben Moshe
- Faculty of Life Sciences, Leslie and Gonda (Goldschmied) Multidisciplinary Brain Research Center, Bar Ilan University, Ramat Gan, Israel
| | - Royi Barnea
- Faculty of Life Sciences, Leslie and Gonda (Goldschmied) Multidisciplinary Brain Research Center, Bar Ilan University, Ramat Gan, Israel
| | - Gal Warhaftig
- Faculty of Life Sciences, Leslie and Gonda (Goldschmied) Multidisciplinary Brain Research Center, Bar Ilan University, Ramat Gan, Israel
| | - Iris Gispan
- Faculty of Life Sciences, Leslie and Gonda (Goldschmied) Multidisciplinary Brain Research Center, Bar Ilan University, Ramat Gan, Israel
| | - Rachel Maayan
- The Laboratory of Molecular Psychiatry, Felsenstein Medical Research Center, Petah Tikva, Israel
- Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Paola Rosca
- Department for the Treatment of Substance Abuse and Mental Health Services, Israeli Ministry of Health, Jerusalem, Israel
- Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Abraham Weizman
- The Laboratory of Molecular Psychiatry, Felsenstein Medical Research Center, Petah Tikva, Israel
- Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Research Unit, Geha Mental Health Center, Petah Tikva, Israel
| | - Gal Yadid
- Faculty of Life Sciences, Leslie and Gonda (Goldschmied) Multidisciplinary Brain Research Center, Bar Ilan University, Ramat Gan, Israel
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Stafford AM, Yamamoto BK, Phillips TJ. Combined and sequential effects of alcohol and methamphetamine in animal models. Neurosci Biobehav Rev 2021; 131:248-269. [PMID: 34543650 PMCID: PMC8642292 DOI: 10.1016/j.neubiorev.2021.09.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 09/11/2021] [Accepted: 09/12/2021] [Indexed: 11/16/2022]
Abstract
Comorbid drug use, often alcohol with other drugs, poses significant health and societal concerns. Methamphetamine is among the illicit drugs most often co-used with alcohol. The current review examines the animal literature for impacts of comorbid alcohol and methamphetamine exposure. We found evidence for additive or synergistic effects of combined or sequential exposure on behavior and physiology. Dopaminergic, serotonergic, and glutamatergic systems are all impacted by combined exposure to alcohol and methamphetamine and cyclooxygenase-2 activity plays an important role in their combined neurotoxic effects. Adverse consequences of comorbid exposure include altered brain development with prenatal exposure, impaired learning and memory, motor deficits, gastrotoxicity, hepatotoxicity, and augmented intake under some conditions. Given high susceptibility to drug experimentation in adolescence, studies of co-exposure during the adolescent period and of how adolescent exposure to one drug impacts later use or sensitivity to the other drug should be a priority. Further, to gain traction on prevention and treatment, additional research to identify motivational and neurobiological drivers and consequences of comorbid use is needed.
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Affiliation(s)
- Alexandra M Stafford
- Department of Behavioral Neuroscience, Portland Alcohol Abuse Research Center and Methamphetamine Abuse Research Center, Oregon Health & Science University, Portland, OR, USA.
| | - Bryan K Yamamoto
- Department of Pharmacology & Toxicology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Tamara J Phillips
- Department of Behavioral Neuroscience, Portland Alcohol Abuse Research Center and Methamphetamine Abuse Research Center, Oregon Health & Science University, Portland, OR, USA; Veterans Affairs Portland Health Care System, Portland, OR, USA
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Maccioni P, Kaczanowska K, Lawrence H, Yun S, Bratzu J, Gessa GL, McDonald P, Colombo G. The Novel Positive Allosteric Modulator of the GABA B Receptor, KK-92A, Suppresses Alcohol Self-Administration and Cue-Induced Reinstatement of Alcohol Seeking in Rats. Front Cell Dev Biol 2021; 9:727576. [PMID: 34778249 PMCID: PMC8585307 DOI: 10.3389/fcell.2021.727576] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Accepted: 10/07/2021] [Indexed: 11/13/2022] Open
Abstract
Positive allosteric modulators (PAMs) of the GABAB receptor (GABAB PAMs) are of interest in the addiction field due to their ability to suppress several behaviors motivated by drugs of abuse. KK-92A is a novel GABAB PAM found to attenuate intravenous self-administration of nicotine and reinstatement of nicotine seeking in rats. This present study was aimed at extending to alcohol the anti-addictive properties of KK-92A. To this end, Sardinian alcohol-preferring rats were trained to lever-respond for oral alcohol (15% v/v) or sucrose (0.7% w/v) under the fixed ratio (FR) 5 (FR5) schedule of reinforcement. Once lever-responding behavior had stabilized, rats were exposed to tests with acutely administered KK-92A under FR5 and progressive ratio schedules of reinforcement and cue-induced reinstatement of previously extinguished alcohol seeking. KK-92A effect on spontaneous locomotor activity was also evaluated. Treatment with 10 and 20 mg/kg KK-92A suppressed lever-responding for alcohol, amount of self-administered alcohol, and breakpoint for alcohol. Treatment with 20 mg/kg KK-92A reduced sucrose self-administration. Combination of per se ineffective doses of KK-92A (2.5 mg/kg) and the GABAB receptor agonist, baclofen (1 mg/kg), reduced alcohol self-administration. Treatment with 5, 10, and 20 mg/kg KK-92A suppressed reinstatement of alcohol seeking. Only treatment with 80 mg/kg KK-92A affected spontaneous locomotor activity. These results demonstrate the ability of KK-92A to inhibit alcohol-motivated behaviors in rodents and confirm that these effects are common to the entire class of GABAB PAMs. The remarkable efficacy of KK-92A is discussed in terms of its ago-allosteric properties.
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Affiliation(s)
- Paola Maccioni
- Neuroscience Institute, Section of Cagliari, National Research Council of Italy, Monserrato, Italy
| | - Katarzyna Kaczanowska
- Department of Chemistry, The Scripps Research Institute, La Jolla, CA, United States
| | - Harshani Lawrence
- Chemical Biology Core, Moffitt Cancer Center, Tampa, FL, United States
| | - Sang Yun
- Chemical Biology Core, Moffitt Cancer Center, Tampa, FL, United States
| | - Jessica Bratzu
- Neuroscience Institute, Section of Cagliari, National Research Council of Italy, Monserrato, Italy
| | - Gian Luigi Gessa
- Neuroscience Institute, Section of Cagliari, National Research Council of Italy, Monserrato, Italy
| | - Patricia McDonald
- Department of Cancer Physiology, Moffitt Cancer Center, Tampa, FL, United States
| | - Giancarlo Colombo
- Neuroscience Institute, Section of Cagliari, National Research Council of Italy, Monserrato, Italy
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6
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Vlachou S. A Brief History and the Significance of the GABA B Receptor. Curr Top Behav Neurosci 2021; 52:1-17. [PMID: 34595739 DOI: 10.1007/7854_2021_264] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
γ-Aminobutyric acid (GABA) is the main inhibitory neurotransmitter in the brain. GABA type B (GABAB) receptors (GABABRs) are the only metabotropic G protein-coupled receptors for GABA and can be found distributed not only in the central nervous system, but also in the periphery. This chapter introduces important, fundamental knowledge related to GABABR function and the various potential therapeutic applications of the development of novel GABABR-active compounds, as documented through extensive studies presented in subsequent chapters of this Current Topic in Behavioral Neurosciences volume on the role of the neurobiology of GABABR function. The compounds that have received increased attention in the last few years compared to GABABR agonists and antagonists - the positive allosteric modulators - exhibit better pharmacological profiles and fewer side effects. As we continue to unveil the mystery of GABABRs at the molecular and cellular levels, we further understand the significance of these receptors. Future directions should aim for developing highly selective GABABR compounds for treating neuropsychiatric disorders and their symptomatology.
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Affiliation(s)
- Styliani Vlachou
- Neuropsychopharmacology Division, Behavioural Neuroscience Laboratory, School of Psychology, Faculty of Science and Health, Dublin City University, Dublin, Ireland.
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7
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Varani AP, Pedrón VT, Aon AJ, Canero EM, Balerio GN. GABA B receptors blockage modulates somatic and aversive manifestations induced by nicotine withdrawal. Biomed Pharmacother 2021; 140:111786. [PMID: 34144406 DOI: 10.1016/j.biopha.2021.111786] [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: 03/22/2021] [Revised: 05/21/2021] [Accepted: 05/25/2021] [Indexed: 10/21/2022] Open
Abstract
There is substantial evidence that GABAB agonist, baclofen, prevents somatic and motivational responses induced by nicotine withdrawal and may target drug cue vulnerabilities in humans. In this context, we explored different aspects associated with the possible mechanisms whereby the GABAB receptors might influence nicotine withdrawal. Male mice received nicotine (2.5 mg/kg, s.c.) 4 times daily, for 7 consecutive days. Nicotine-treated mice received the nicotinic acetylcholine receptor antagonist, mecamylamine (MEC, 2 or 3.5 mg/kg, s.c.), to precipitate the withdrawal state. A second group of dependent mice received 2-hydroxysaclofen (GABAB receptor antagonist, 1 mg/kg, s.c.) before MEC-precipitated abstinence. Somatic signs of nicotine withdrawal were measured for 30 min. Anxiogenic-like response associated to nicotine withdrawal was assessed by the elevated plus maze test. The dysphoric/aversive effect induced by nicotine withdrawal was evaluated using conditioned place aversion paradigm. Dopamine, serotonin and its metabolites concentrations were determined by HPLC in the striatum, cortex and hippocampus. Finally, α4β2 nicotinic acetylcholine receptor density was determined in several brain regions using autoradiography assays. The results showed that MEC-precipitated nicotine withdrawal induced somatic manifestations, anxiogenic-like response and dysphoric/aversive effect, and 2-hydroxysaclofen potentiated these behavioral responses. Additionally, 2-hydroxysaclofen was able to change striatal dopamine levels and α4β2 nicotinic acetylcholine receptor density, both altered by MEC-precipitated nicotine withdrawal. These findings provide important contributions to elucidate neurobiological mechanisms implicated in nicotine withdrawal. We suggest that GABAB receptor activity is necessary to control alterations induced by nicotine withdrawal, which supports the idea of targeting GABAB receptors to treat tobacco addiction in humans.
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Affiliation(s)
- A P Varani
- CONICET, Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Instituto de Investigaciones Farmacológicas (ININFA-UBA-CONICET), Junín 956, 5° Piso, Buenos Aires C1113AAD, Argentina
| | - V T Pedrón
- CONICET, Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Instituto de Investigaciones Farmacológicas (ININFA-UBA-CONICET), Junín 956, 5° Piso, Buenos Aires C1113AAD, Argentina
| | - A J Aon
- CONICET, Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Instituto de Investigaciones Farmacológicas (ININFA-UBA-CONICET), Junín 956, 5° Piso, Buenos Aires C1113AAD, Argentina
| | - E M Canero
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica (FFYB), Cátedra de Farmacología, Junín 956, 5° Piso, Buenos Aires C1113AAD, Argentina; CONICET, Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Instituto de Investigaciones Farmacológicas (ININFA-UBA-CONICET), Junín 956, 5° Piso, Buenos Aires C1113AAD, Argentina
| | - G N Balerio
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica (FFYB), Cátedra de Farmacología, Junín 956, 5° Piso, Buenos Aires C1113AAD, Argentina; CONICET, Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Instituto de Investigaciones Farmacológicas (ININFA-UBA-CONICET), Junín 956, 5° Piso, Buenos Aires C1113AAD, Argentina.
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Stafford AM, Reed C, Phillips TJ. Non-genetic factors that influence methamphetamine intake in a genetic model of differential methamphetamine consumption. Psychopharmacology (Berl) 2020; 237:3315-3336. [PMID: 32833064 PMCID: PMC7572688 DOI: 10.1007/s00213-020-05614-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 07/17/2020] [Indexed: 12/20/2022]
Abstract
RATIONALE Genetic and non-genetic factors influence substance use disorders. Our previous work in genetic mouse models focused on genetic factors that influence methamphetamine (MA) intake. The current research examined several non-genetic factors for their potential influence on this trait. OBJECTIVES We examined the impact on MA intake of several non-genetic factors, including MA access schedule, prior forced MA exposure, concomitant ethanol (EtOH) access, and gamma-aminobutyric acid type B (GABAB) receptor activation. Selectively bred MA high drinking (MAHDR) and low drinking (MALDR) mice participated in this research. RESULTS MAHDR, but not MALDR, mice increased MA intake when given intermittent access, compared with continuous access, with a water choice under both schedules. MA intake was not altered by previous exposure to forced MA consumption. Male MAHDR mice given simultaneous access to MA, EtOH, and an EtOH+MA mixture exhibited a strong preference for MA over EtOH and EtOH+MA; MA intake was not affected by EtOH in female MAHDR mice. When independent MAHDR groups were given access to MA, EtOH, or EtOH+MA vs. water in each case, MA intake was reduced in the water vs. EtOH+MA group, compared with the water vs. MA group. The GABAB receptor agonist R(+)-baclofen (BAC) not only reduced MA intake but also reduced water intake and locomotor activity in MAHDR mice. There was a residual effect of BAC, such that MA intake was increased after termination of BAC treatment. CONCLUSIONS These findings demonstrate that voluntary MA intake in MAHDR mice is influenced by non-genetic factors related to MA access schedule and co-morbid EtOH exposure.
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Affiliation(s)
- A M Stafford
- Department of Behavioral Neuroscience and Methamphetamine Abuse Research Center, Oregon Health & Science University, Portland, OR, USA
| | - C Reed
- Department of Behavioral Neuroscience and Methamphetamine Abuse Research Center, Oregon Health & Science University, Portland, OR, USA
| | - T J Phillips
- Department of Behavioral Neuroscience and Methamphetamine Abuse Research Center, Oregon Health & Science University, Portland, OR, USA.
- Veterans Affairs Portland Health Care System, Portland, OR, USA.
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Su H, Chen T, Zhong N, Jiang H, Du J, Xiao K, Xu D, Wang Z, Zhao M. γ-aminobutyric acid and glutamate/glutamine alterations of the left prefrontal cortex in individuals with methamphetamine use disorder: a combined transcranial magnetic stimulation-magnetic resonance spectroscopy study. ANNALS OF TRANSLATIONAL MEDICINE 2020; 8:347. [PMID: 32355791 PMCID: PMC7186735 DOI: 10.21037/atm.2020.02.95] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Background GABAergic and glutamatergic neurotransmitter systems are critical in the pathophysiology of addiction and represent potential targets for repetitive transcranial magnetic stimulation (rTMS). This study aims to investigate changes in γ-aminobutyric acid (GABA) levels, the combined resonance of glutamate and glutamine (Glx) in the left dorsolateral prefrontal cortex (DLPFC), and cognitive function of patients with methamphetamine dependence following rTMS intervention, using proton magnetic resonance spectroscopy (1H MRS). Methods Fifty methamphetamine-dependent patients were randomized to a 4-week course of active or sham rTMS, with 1H MRS measurement of DLPFC GABA and Glx levels relative to n-acetyl-aspartate (NAA) and craving and cognitive function measured at baseline and post-intervention. Results We observed significant reductions of GABA/NAA concentration in the active group and Glx/NAA concentration in the group receiving sham rTMS. There was a significant association between changes in GABA concentration and problem solving/error monitoring. Conclusions The effect of rTMS on cognitive function in individuals with methamphetamine dependence may be related to changes in GABA levels in the prefrontal cortex, and warrants further investigation.
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Affiliation(s)
- Hang Su
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, China
| | - Tianzhen Chen
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, China
| | - Na Zhong
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, China
| | - Haifeng Jiang
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, China
| | - Jiang Du
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, China
| | - Ke Xiao
- Shanghai Drug Rehabilitation Administration Bureau, Shanghai 200080, China
| | - Ding Xu
- Shanghai Drug Rehabilitation Administration Bureau, Shanghai 200080, China
| | - Zheng Wang
- Institute of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, State Key laboratory of Neuroscience, CAS Key Laboratory of Primate Neurobiology, Chinese Academy of Sciences, Shanghai 200031, China.,University of Chinese Academy of Sciences, Beijing 100049, China.,CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai 200031, China
| | - Min Zhao
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, China.,CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai 200031, China.,Shanghai Key Laboratory of Psychotic Disorders, Shanghai 201108, China.,Institute of Psychological and Behavioral Science, Shanghai Jiao Tong University, Shanghai 200030, China
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10
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Su H, Chen T, Zhong N, Jiang H, Du J, Xiao K, Xu D, Song W, Zhao M. Decreased GABA concentrations in left prefrontal cortex of methamphetamine dependent patients: A proton magnetic resonance spectroscopy study. J Clin Neurosci 2020; 71:15-20. [DOI: 10.1016/j.jocn.2019.11.021] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 10/09/2019] [Accepted: 11/19/2019] [Indexed: 12/25/2022]
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11
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Neasta J, Darcq E, Jeanblanc J, Carnicella S, Ben Hamida S. GPCR and Alcohol-Related Behaviors in Genetically Modified Mice. Neurotherapeutics 2020; 17:17-42. [PMID: 31919661 PMCID: PMC7007453 DOI: 10.1007/s13311-019-00828-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
G protein-coupled receptors (GPCRs) constitute the largest class of cell surface signaling receptors and regulate major neurobiological processes. Accordingly, GPCRs represent primary targets for the treatment of brain disorders. Several human genetic polymorphisms affecting GPCRs have been associated to different components of alcohol use disorder (AUD). Moreover, GPCRs have been reported to contribute to several features of alcohol-related behaviors in animal models. Besides traditional pharmacological tools, genetic-based approaches mostly aimed at deleting GPCR genes provided substantial information on how key GPCRs drive alcohol-related behaviors. In this review, we summarize the alcohol phenotypes that ensue from genetic manipulation, in particular gene deletion, of key GPCRs in rodents. We focused on GPCRs that belong to fundamental neuronal systems that have been shown as potential targets for the development of AUD treatment. Data are reviewed with particular emphasis on alcohol reward, seeking, and consumption which are behaviors that capture essential aspects of AUD. Literature survey indicates that in most cases, there is still a gap in defining the intracellular transducers and the functional crosstalk of GPCRs as well as the neuronal populations in which their signaling regulates alcohol actions. Further, the implication of only a few orphan GPCRs has been so far investigated in animal models. Combining advanced pharmacological technologies with more specific genetically modified animals and behavioral preclinical models is likely necessary to deepen our understanding in how GPCR signaling contributes to AUD and for drug discovery.
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Affiliation(s)
- Jérémie Neasta
- Laboratoire de Pharmacologie, Faculté de Pharmacie, University of Montpellier, 34093, Montpellier, France
| | - Emmanuel Darcq
- Douglas Hospital Research Center, Department of Psychiatry, McGill University, 6875 Boulevard LaSalle, Montreal, Quebec, H4H 1R3, Canada
| | - Jérôme Jeanblanc
- Research Group on Alcohol and Pharmacodependences-INSERM U1247, University of Picardie Jules Verne, 80025, Amiens, France
| | - Sebastien Carnicella
- INSERM U1216, Grenoble Institut des Neurosciences (GIN), University of Grenoble Alpes, 38000, Grenoble, France
| | - Sami Ben Hamida
- Douglas Hospital Research Center, Department of Psychiatry, McGill University, 6875 Boulevard LaSalle, Montreal, Quebec, H4H 1R3, Canada.
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12
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Li X, Slesinger PA. GABA B Receptors and Drug Addiction: Psychostimulants and Other Drugs of Abuse. Curr Top Behav Neurosci 2020; 52:119-155. [PMID: 33442842 DOI: 10.1007/7854_2020_187] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Metabotropic GABAB receptors (GABABRs) mediate slow inhibition and modulate synaptic plasticity throughout the brain. Dysfunction of GABABRs has been associated with psychiatric illnesses and addiction. Drugs of abuse alter GABAB receptor (GABABR) signaling in multiple brain regions, which partly contributes to the development of drug addiction. Recently, GABABR ligands and positive allosteric modulators (PAMs) have been shown to attenuate the initial rewarding effect of addictive substances, inhibit seeking and taking of these drugs, and in some cases, ameliorate drug withdrawal symptoms. The majority of the anti-addiction effects seen with GABABR modulation can be localized to ventral tegmental area (VTA) dopamine neurons, which receive complex inhibitory and excitatory inputs that are modified by drugs of abuse. Preclinical research suggests that GABABR PAMs are emerging as promising candidates for the treatment of drug addiction. Clinical studies on drug dependence have shown positive results with GABABR ligands but more are needed, and compounds with better pharmacokinetics and fewer side effects are critically needed.
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Affiliation(s)
- Xiaofan Li
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
| | - Paul A Slesinger
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
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13
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Zhao Y, Peng S, Jiang H, Du J, Yu S, Zhao M. Variants in GABBR1 Gene Are Associated with Methamphetamine Dependence and Two Years' Relapse after Drug Rehabilitation. J Neuroimmune Pharmacol 2018; 13:523-531. [PMID: 30143926 DOI: 10.1007/s11481-018-9802-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 07/30/2018] [Indexed: 01/18/2023]
Abstract
Methamphetamine (MA) use disorder is a growing global health challenge marked by a steady increase worldwide. GABAergic system plays an important role in the mechanism of drug dependence, however few studies about the association between methamphetamine use disorder and genes in GABAergic system. Concerning GABBR1 gene which encoding the GABAB receptor subunit 1 is an important regulator in the GABAergic system. The aim of the study is to explore whether GABBR1 gene play a role in methamphetamine dependence and relapse after rehabilitation. Three single nucleotide polymorphisms (SNPs, rs2076483, rs29221, rs715044) of the GABBR1 gene were genotyped in 791 participants with MA use disorder and 448 healthy controls. The distribution of genotypes and alleles of the three SNPs between the two groups and their subgroups (dependence and abuse) was been analyzed. The multivariate logistic model was used to identify factors associate with relapse of MA use disorder during the following 2 years after drug rehabilitation. It was found that the C allele frequency of rs715044 of the GABBR1 gene was associated with MA use disorder and MA dependence. The CGA (rs2076483- rs29221- rs715044) was negatively associated with MA use disorder. The drug use years and rs29221 GG genotype were associated with relapse during the following 2 years after drug rehabilitation. GABBR1 gene may be associated with the susceptibility for MA use disorder and relapse and it indicates that the GABAergic system may play a role in the MA use disorder. Graphical Abstract GABBR1 gene may be associated with the susceptibility for MA use disorder and relapse and it indicates that the GABAergic system may play a role in the MA use disorder.
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Affiliation(s)
- Yan Zhao
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, 200030, China
| | - Sufang Peng
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, 200030, China
| | - Haifeng Jiang
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, 200030, China
| | - Jiang Du
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, 200030, China
| | - Shunying Yu
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, 200030, China
| | - Min Zhao
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, 200030, China.
- Shanghai Key Laboratory of Psychotic Disorders, Shanghai, 200030, China.
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14
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Farokhnia M, Sheskier MB, Lee MR, Le AN, Singley E, Bouhlal S, Ton T, Zhao Z, Leggio L. Neuroendocrine response to GABA-B receptor agonism in alcohol-dependent individuals: Results from a combined outpatient and human laboratory experiment. Neuropharmacology 2018; 137:230-239. [PMID: 29665351 PMCID: PMC6050109 DOI: 10.1016/j.neuropharm.2018.04.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 04/05/2018] [Accepted: 04/10/2018] [Indexed: 12/13/2022]
Abstract
Gamma-aminobutyric acid (GABA), the main inhibitory neurotransmitter in the nervous system, plays an important role in biobehavioral processes that regulate alcohol seeking, food intake, and stress response. The metabotropic GABA-B receptor has been investigated as a potential therapeutic target for alcohol use disorder, by using orthosteric agonists (e.g., baclofen) and positive allosteric modulators. Whether and how pharmacological manipulation of the GABA-B receptor, in combination with alcohol intake, may affect feeding- and stress-related neuroendocrine pathways remains unknown. In the present randomized, double-blind, placebo-controlled study, thirty-four alcohol-dependent individuals received baclofen (30 mg/day) or placebo in a naturalistic outpatient setting for one week, and then performed a controlled laboratory experiment which included alcohol cue-reactivity, fixed-dose priming, and self-administration procedures. Blood samples were collected, and the following neuroendocrine markers were measured: ghrelin, leptin, amylin, glucagon-like peptide-1 (GLP-1), insulin, prolactin, thyroid-stimulating hormone, growth hormone, cortisol, and adrenocorticotropic hormone (ACTH). During the outpatient phase, baclofen significantly increased blood concentrations of acyl-ghrelin (p = 0.01), leptin (p = 0.01), amylin (p = 0.004), and GLP-1 (p = 0.02). Significant drug × time-point interaction effects for amylin (p = 0.001) and insulin (p = 0.03), and trend-level interaction effects for GLP-1 (p = 0.06) and ACTH (p = 0.10) were found during the laboratory experiment. Baclofen, compared to placebo, had no effect on alcohol drinking in this study (p's ≥ 0.05). Together with previous studies, these findings shed light on the role of the GABAergic system and GABA-B receptors in the shared neurobiology of alcohol-, feeding-, and stress-related behaviors.
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Affiliation(s)
- Mehdi Farokhnia
- Section on Clinical Psychoneuroendocrinology and Neuropsychopharmacology, National Institute on Alcohol Abuse and Alcoholism and National Institute on Drug Abuse, National Institutes of Health, Bethesda, MD, USA
| | - Mikela B Sheskier
- Section on Clinical Psychoneuroendocrinology and Neuropsychopharmacology, National Institute on Alcohol Abuse and Alcoholism and National Institute on Drug Abuse, National Institutes of Health, Bethesda, MD, USA
| | - Mary R Lee
- Section on Clinical Psychoneuroendocrinology and Neuropsychopharmacology, National Institute on Alcohol Abuse and Alcoholism and National Institute on Drug Abuse, National Institutes of Health, Bethesda, MD, USA
| | - April N Le
- Section on Clinical Psychoneuroendocrinology and Neuropsychopharmacology, National Institute on Alcohol Abuse and Alcoholism and National Institute on Drug Abuse, National Institutes of Health, Bethesda, MD, USA
| | - Erick Singley
- Clinical Core Laboratory, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, USA
| | - Sofia Bouhlal
- Section on Clinical Psychoneuroendocrinology and Neuropsychopharmacology, National Institute on Alcohol Abuse and Alcoholism and National Institute on Drug Abuse, National Institutes of Health, Bethesda, MD, USA
| | - Timmy Ton
- Department of Laboratory Medicine, Clinical Center, National Institutes of Health, Bethesda, MD, USA
| | - Zhen Zhao
- Department of Laboratory Medicine, Clinical Center, National Institutes of Health, Bethesda, MD, USA
| | - Lorenzo Leggio
- Section on Clinical Psychoneuroendocrinology and Neuropsychopharmacology, National Institute on Alcohol Abuse and Alcoholism and National Institute on Drug Abuse, National Institutes of Health, Bethesda, MD, USA; Center for Alcohol and Addiction Studies, Department of Behavioral and Social Sciences, Brown University, Providence, RI, USA.
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15
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The Cerebellar GABA AR System as a Potential Target for Treating Alcohol Use Disorder. Handb Exp Pharmacol 2018; 248:113-156. [PMID: 29736774 DOI: 10.1007/164_2018_109] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
In the brain, fast inhibitory neurotransmission is mediated primarily by the ionotropic subtype of the gamma-aminobutyric acid (GABA) receptor subtype A (GABAAR). It is well established that the brain's GABAAR system mediates many aspects of neurobehavioral responses to alcohol (ethanol; EtOH). Accordingly, in both preclinical studies and some clinical scenarios, pharmacologically targeting the GABAAR system can alter neurobehavioral responses to acute and chronic EtOH consumption. However, many of the well-established interactions of EtOH and the GABAAR system have been identified at concentrations of EtOH ([EtOH]) that would only occur during abusive consumption of EtOH (≥40 mM), and there are still inadequate treatment options for prevention of or recovery from alcohol use disorder (AUD, including abuse and dependence). Accordingly, there is a general acknowledgement that more research is needed to identify and characterize: (1) neurobehavioral targets of lower [EtOH] and (2) associated brain structures that would involve such targets in a manner that may influence the development and maintenance of AUDs.Nearly 15 years ago it was discovered that the GABAAR system of the cerebellum is highly sensitive to EtOH, responding to concentrations as low as 10 mM (as would occur in the blood of a typical adult human after consuming 1-2 standard units of EtOH). This high sensitivity to EtOH, which likely mediates the well-known motor impairing effects of EtOH, combined with recent advances in our understanding of the role of the cerebellum in non-motor, cognitive/emotive/reward processes has renewed interest in this system in the specific context of AUD. In this chapter we will describe recent advances in our understanding of cerebellar processing, actions of EtOH on the cerebellar GABAAR system, and the potential relationship of such actions to the development of AUD. We will finish with speculation about how cerebellar specific GABAAR ligands might be effective pharmacological agents for treating aspects of AUD.
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16
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Durant CF, Paterson LM, Turton S, Wilson SJ, Myers JFM, Muthukumaraswamy S, Venkataraman A, Mick I, Paterson S, Jones T, Nahar LK, Cordero RE, Nutt DJ, Lingford-Hughes A. Using Baclofen to Explore GABA-B Receptor Function in Alcohol Dependence: Insights From Pharmacokinetic and Pharmacodynamic Measures. Front Psychiatry 2018; 9:664. [PMID: 30618857 PMCID: PMC6302106 DOI: 10.3389/fpsyt.2018.00664] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Accepted: 11/19/2018] [Indexed: 12/20/2022] Open
Abstract
Background: The role of GABA-B neurotransmission in addiction has recently received increased attention, with clinical trials indicating that baclofen, a GABA-B receptor agonist, may reduce alcohol consumption, craving and promote abstinence. However, the optimal dose to treat alcohol dependence is unclear with patients requesting and tolerating much higher doses of baclofen, compared with other clinical uses. We assessed the pharmacokinetics and pharmacodynamics (PK/PD) of baclofen to provide insight into GABA-B sensitivity in this patient group, relative to controls. Methods: Male healthy volunteers (controls, n = 12) and abstinent alcohol dependent individuals (AD, n = 8) received single oral doses of baclofen or placebo in a 3-way crossover design. Controls received placebo/10 mg/60 mg baclofen in a randomized, double-blind design, AD received placebo/60 mg/90 mg baclofen in a single-blind design. PK/PD measures were recorded at baseline and multiple time-points up to 6 h post-dosing, including plasma baclofen, plasma growth hormone (GH), Subjective High Assessment Scale (SHAS) and biphasic alcohol effects scale (BAES). Repeated measures ANOVA analysis explored "change from baseline" dose, time, group, and interaction effects, t-tests compared peak effects. Results: Dose-dependent effects of baclofen on PK and PD measures were observed in both control and AD groups. Whilst there were no significant group differences in any baclofen PK parameters (t 1/2, t max , C max , AUC), marked differences in PD effects were clearly evident. In controls, 60 mg baclofen significantly increased total SHAS and BAES scores, and significantly increased plasma GH levels compared with placebo, with peak effects at 60-120 min, in line with its PK profile. In AD, 60 mg baclofen had limited effects on these parameters; SHAS scores, BAES scores and plasma GH levels were significantly blunted compared with controls (significant group*time interactions P = 0.0014, 0.0015 and P < 0.0001, respectively). Conclusions: Our study shows blunted sensitivity to baclofen in AD relative to controls, with no difference in PK suggesting a lower GABA-B receptor sensitivity. This may explain why higher baclofen doses are requested and tolerated in the treatment of alcohol dependence. Our data has implications for choice of dose in future clinical trials in AD and possibly other substances of dependence.
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Affiliation(s)
- Claire F Durant
- Neuropsychopharmacology Unit, Division of Brain Sciences, Department of Medicine, Centre for Psychiatry, Imperial College London, London, United Kingdom
| | - Louise M Paterson
- Neuropsychopharmacology Unit, Division of Brain Sciences, Department of Medicine, Centre for Psychiatry, Imperial College London, London, United Kingdom
| | - Sam Turton
- Neuropsychopharmacology Unit, Division of Brain Sciences, Department of Medicine, Centre for Psychiatry, Imperial College London, London, United Kingdom
| | - Susan J Wilson
- Neuropsychopharmacology Unit, Division of Brain Sciences, Department of Medicine, Centre for Psychiatry, Imperial College London, London, United Kingdom
| | - James F M Myers
- Neuropsychopharmacology Unit, Division of Brain Sciences, Department of Medicine, Centre for Psychiatry, Imperial College London, London, United Kingdom
| | | | - Ashwin Venkataraman
- Neuropsychopharmacology Unit, Division of Brain Sciences, Department of Medicine, Centre for Psychiatry, Imperial College London, London, United Kingdom
| | - Inge Mick
- Neuropsychopharmacology Unit, Division of Brain Sciences, Department of Medicine, Centre for Psychiatry, Imperial College London, London, United Kingdom
| | - Susan Paterson
- Centre for Brain Science, University of Auckland, Auckland, New Zealand
| | - Tessa Jones
- Neuropsychopharmacology Unit, Division of Brain Sciences, Department of Medicine, Centre for Psychiatry, Imperial College London, London, United Kingdom
| | - Limon K Nahar
- Centre for Brain Science, University of Auckland, Auckland, New Zealand
| | - Rosa E Cordero
- Centre for Brain Science, University of Auckland, Auckland, New Zealand
| | - David J Nutt
- Neuropsychopharmacology Unit, Division of Brain Sciences, Department of Medicine, Centre for Psychiatry, Imperial College London, London, United Kingdom
| | - Anne Lingford-Hughes
- Neuropsychopharmacology Unit, Division of Brain Sciences, Department of Medicine, Centre for Psychiatry, Imperial College London, London, United Kingdom
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17
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Varani AP, Pedrón VT, Aon AJ, Höcht C, Acosta GB, Bettler B, Balerio GN. Nicotine-induced molecular alterations are modulated by GABA B receptor activity. Addict Biol 2018; 23:230-246. [PMID: 28419642 DOI: 10.1111/adb.12506] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Revised: 02/22/2017] [Accepted: 02/23/2017] [Indexed: 12/22/2022]
Abstract
It has been demonstrated that GABAB receptors modulate nicotine (NIC) reward effect; nevertheless, the mechanism implicated is not well known. In this regard, we evaluated the involvement of GABAB receptors on the behavioral, neurochemical, biochemical and molecular alterations associated with the rewarding effects induced by NIC in mice, from a pharmacological and genetic approach. NIC-induced rewarding properties (0.5 mg/kg, subcutaneously, sc) were evaluated by conditioned place preference (CPP) paradigm. CPP has three phases: preconditioning, conditioning and postconditioning. GABAB receptor antagonist 2-hydroxysaclofen (0.25, 0.5 and 1 mg/kg; intraperitoneally, ip) or the GABAB receptor agonist baclofen (3 mg/kg; ip) was injected before NIC during the conditioning phase. GABAB1 knockout (GABAB1 KO) mice received NIC during the conditioning phase. Vehicle and wild-type controls were employed. Neurochemical (dopamine, serotonin and their metabolites), biochemical (nicotinic receptor α4β2, α4β2nAChRs) and molecular (c-Fos) alterations induced by NIC were analyzed after the postconditioning phase by high-performance liquid chromatography (HPLC), receptor-ligand binding assays and immunohistochemistry, respectively, in nucleus accumbens (Acb), prefrontal cortex (PFC) and ventral tegmental area (VTA). NIC induced rewarding effects in the CPP paradigm and increased dopamine levels in Acb and PFC, α4β2nAChRs density in VTA and c-Fos expression in Acb shell (AcbSh), VTA and PFC. We showed that behavioral, neurochemical, biochemical and molecular alterations induced by NIC were prevented by baclofen. However, in 2-hydroxysaclofen pretreated and GABAB1 KO mice, these alterations were potentiated, suggesting that GABAB receptor activity is necessary to control alterations induced by NIC-induced rewarding effects. Therefore, the present findings provided important contributions to the mechanisms implicated in NIC-induced rewarding effects.
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Affiliation(s)
- Andres P Varani
- CONICET - Universidad de Buenos Aires, Instituto de Investigaciones Farmacológicas (ININFA), Buenos Aires, Argentina
| | - Valeria T Pedrón
- CONICET - Universidad de Buenos Aires, Instituto de Investigaciones Farmacológicas (ININFA), Buenos Aires, Argentina
| | - Amira J Aon
- CONICET - Universidad de Buenos Aires, Instituto de Investigaciones Farmacológicas (ININFA), Buenos Aires, Argentina
| | - Christian Höcht
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Cátedra de Farmacología, Buenos Aires, Argentina
| | - Gabriela B Acosta
- CONICET - Universidad de Buenos Aires, Instituto de Investigaciones Farmacológicas (ININFA), Buenos Aires, Argentina
| | - Bernhard Bettler
- Department of Biomedicine, Institute of Physiology, Pharmazentrum, University of Basel, Switzerland
| | - Graciela N Balerio
- CONICET - Universidad de Buenos Aires, Instituto de Investigaciones Farmacológicas (ININFA), Buenos Aires, Argentina
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Cátedra de Farmacología, Buenos Aires, Argentina
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18
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Maccioni P, Lorrai I, Contini A, Leite-Morris K, Colombo G. Microinjection of baclofen and CGP7930 into the ventral tegmental area suppresses alcohol self-administration in alcohol-preferring rats. Neuropharmacology 2017; 136:146-158. [PMID: 29050951 DOI: 10.1016/j.neuropharm.2017.10.012] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Revised: 10/08/2017] [Accepted: 10/11/2017] [Indexed: 01/05/2023]
Abstract
Systemic administration of the orthosteric agonist, baclofen, and several positive allosteric modulators (PAMs) of the GABAB receptor has repeatedly been reported to decrease operant oral alcohol self-administration in rats. The aim of the present study was to evaluate the contribution of the mesolimbic dopamine system to the reducing effect of baclofen and GABAB PAMs on the reinforcing properties of alcohol. To this end, baclofen or the GABAB PAM CGP7930 were microinjected into the ventral tegmental area (VTA) of selectively bred, Sardinian alcohol-preferring (sP) rats trained to self-administer alcohol. Baclofen (0, 0.03, 0.1, and 0.3 μg) or CGP7930 (0, 5, 10, and 20 μg) were microinjected via indwelling unilateral guide cannula aiming at the left hemisphere of the VTA. Treatment with baclofen resulted in a dose-related suppression of the number of lever-responses for alcohol and the amount of self-administered alcohol. No dose of baclofen altered rat motor-performance, evaluated by the inverted screen test immediately before the self-administration session. Treatment with CGP7930 halved the number of lever-responses for alcohol and amount of self-administered alcohol, with no effect on rat motor-performance. Site-specificity was investigated testing the effect of microinjection of baclofen and CGP7930 into the left hemisphere of deep mesencephalic nucleus: compared to vehicle, neither 0.3 μg baclofen nor 20 μg CGP7930 altered lever-responding for alcohol and amount of self-administered alcohol. Collectively, the results of the present study suggest the involvement of GABAB receptors located in the VTA in the mediation of alcohol reinforcing properties in sP rats. This article is part of the "Special Issue Dedicated to Norman G. Bowery".
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Affiliation(s)
- Paola Maccioni
- Neuroscience Institute, Section of Cagliari, National Research Council of Italy, Monserrato, CA I-09042, Italy
| | - Irene Lorrai
- Neuroscience Institute, Section of Cagliari, National Research Council of Italy, Monserrato, CA I-09042, Italy
| | - Andrea Contini
- Department of Biomedical Sciences, University of Sassari, Sassari, SS I-07100, Italy
| | - Kimberly Leite-Morris
- Departments of Psychiatry, Pharmacology and Experimental Therapeutics, Boston University School of Medicine, VA Boston Healthcare System, Research Service, Boston, MA 02130, USA
| | - Giancarlo Colombo
- Neuroscience Institute, Section of Cagliari, National Research Council of Italy, Monserrato, CA I-09042, Italy.
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19
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Alavian F, Ghiasvand S. GABA B receptors within the central nucleus of amygdala may involve in the morphine-induced incentive tolerance in female rats. IRANIAN JOURNAL OF BASIC MEDICAL SCIENCES 2017; 20:822-828. [PMID: 28852448 PMCID: PMC5569599 DOI: 10.22038/ijbms.2017.9018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Objective(s): Central nucleus of amygdala (CeA) is the most important region for morphine-induced reward, and GABAergic system plays an important role on morphine reinforcement. The influence of CeA administration of GABAB receptor agonist and antagonist on the expression and acquisition of morphine-induced incentive tolerance using conditioned place preference (CPP) paradigm was investigated in the present study. Our purpose was to evaluate the role of CeA GABAB receptors in morphine tolerance. Materials and Methods: Seven days after surgery and cannulation, the experiments were begun. Subcutaneous (SC) injections of morphine induced CPP. Administration of one daily dose of morphine (12.5 mg/kg) for 3 days in order to develop tolerance to the drug reduced the conditioning induced by morphine (7.5 mg/kg, SC). GABAB receptor agonist, baclofen (1.5, 6 and 12 µg/rat) or GABAB receptor antagonist, CGP35348 (1.5, 6 and 12 µg/rat) were injected into the CeA 5 min before the experiments in the test day (expression of tolerance) or 5 min before each injection of morphine (12.5 mg/kg) (acquisition of tolerance). Results: It was shown that injections of baclofen (1.5 and 12 µg/rat) reduced acquisition, whereas the dose of 6 µg/rat of the drug exacerbated the acquisition of morphine tolerance. Baclofen at all doses significantly increased the expression of tolerance to morphine. Administration of CGP35348 (1.5, 6 and 12 µg/rat) reduced the acquisition and expression of morphine tolerance. Conclusion: These results confirmed the importance of GABAB receptors with in the CeA in morphine tolerance in female rats.
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Affiliation(s)
- Firoozeh Alavian
- Department of Basic Sciences, Farhangian University, Tehran, Iran
| | - Saeedeh Ghiasvand
- Departments of Biology, Faculty of Science, Malayer University, Malayer, Iran
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20
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Biobehavioral effects of baclofen in anxious alcohol-dependent individuals: a randomized, double-blind, placebo-controlled, laboratory study. Transl Psychiatry 2017; 7:e1108. [PMID: 28440812 PMCID: PMC5416708 DOI: 10.1038/tp.2017.71] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Revised: 01/10/2017] [Accepted: 01/28/2017] [Indexed: 12/20/2022] Open
Abstract
Baclofen has been suggested as a potential pharmacotherapy for alcohol use disorder, but the clinical data are conflicting. Here we investigated the biobehavioral effects of baclofen in a sample of anxious alcohol-dependent individuals. This was a randomized, double-blind, placebo-controlled, human laboratory study in non-treatment seeking alcohol-dependent individuals with high trait anxiety (N=34). Participants received baclofen (30 mg per day) or placebo for at least 8 days, then performed an experimental session consisting of alcohol cue-reactivity followed by alcohol administration procedure (alcohol priming, then alcohol self-administration). Total amount of alcohol self-administered was the primary outcome; alcohol craving, subjective/physiological responses and mood/anxiety symptoms were also evaluated. There was no significant medication effect on the total amount of alcohol consumed during the alcohol self-administration (P=0.76). Baclofen blunted the positive association between maximum breath alcohol concentration during priming and the amount of alcohol consumption (significant interaction, P=0.03). Ratings of feeling intoxicated were significantly higher in the baclofen group after consuming the priming drink (P=0.006). During the self-administration session, baclofen significantly increased ratings of feeling high (P=0.01) and intoxicated (P=0.01). A significant reduction in heart rate (P<0.001) and a trend-level increase in diastolic blood pressure (P=0.06) were also detected in the baclofen group during the alcohol laboratory session. In conclusion, baclofen was shown to affect subjective and physiological responses to alcohol drinking in anxious alcohol-dependent individuals. These results do not support an anti-craving or anti-reinforcing effect of baclofen, but rather suggest that baclofen may act as a substitution medication for alcohol use disorder.
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Maccioni P, Lorrai I, Carai MAM, Riva A, Morazzoni P, Mugnaini C, Corelli F, Gessa GL, Colombo G. Reducing effect of saikosaponin A, an active ingredient of Bupleurum falcatum, on alcohol self-administration in rats: Possible involvement of the GABAB receptor. Neurosci Lett 2016; 621:62-67. [PMID: 27080427 DOI: 10.1016/j.neulet.2016.04.022] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Revised: 03/25/2016] [Accepted: 04/09/2016] [Indexed: 11/18/2022]
Abstract
Recent studies demonstrated that treatment with saikosaponin A (SSA) - an active ingredient of the medicinal herb, Bupleurum falcatum L. - selectively suppressed, likely via a GABAB receptor-mediated mechanism, intravenous self-administration of morphine and cocaine in rats [Yoon et al., 2012; 2013]. The present study was designed to investigate whether the capacity of SSA to suppress morphine and cocaine self-administration extends to oral alcohol self-administration. To this end, selectively bred Sardinian alcohol-preferring (sP) rats were trained to lever-respond on a Fixed Ratio (FR) 4 (FR4) schedule of reinforcement for alcohol (15%, v/v) in daily 30-min sessions. Once responding had stabilized, rats were tested under the FR4 (measure of alcohol reinforcing properties) and Progressive Ratio (PR; measure of alcohol motivational properties) schedules of reinforcement. The possible involvement of the GABAB receptor system was investigated testing the effect of (a) pretreatment with the GABAB receptor antagonist, SCH50911, and (b) combined treatment with the positive allosteric modulator of the GABAB receptor, GS39783. Treatment with SSA (0, 0.25, 0.5, and 1mg/kg, i.p.) markedly reduced lever-responding for alcohol, amount of self-administered alcohol, and breakpoint for alcohol (defined as the lowest response requirement not achieved in the PR experiment). Pretreatment with 2mg/kg SCH50911 (i.p.) resulted in a partial blockade of the reducing effect of 0.5mg/kg SSA on lever-responding for alcohol and amount of self-administered alcohol. Combination of per se ineffective doses of GS39783 (5mg/kg, i.g.) and SSA (0.1mg/kg, i.p.) reduced lever-responding for alcohol and amount of self-administered alcohol. These results (a) extend to alcohol self-administration the capacity of SSA to suppress morphine and cocaine self-administration in rats and (b) suggest that the GABAB receptor system is likely part of the neural substrate underlying the reducing effect of SSA on alcohol self-administration.
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Affiliation(s)
- Paola Maccioni
- Neuroscience Institute, National Research Council of Italy, Section of Cagliari, I-09042 Monserrato, CA, Italy
| | - Irene Lorrai
- Neuroscience Institute, National Research Council of Italy, Section of Cagliari, I-09042 Monserrato, CA, Italy
| | - Mauro A M Carai
- Cagliari Pharmacological Research s.r.l., I-09127 Cagliari, CA, Italy
| | | | | | - Claudia Mugnaini
- Department of Biotechnologies, Chemistry and Pharmacy, University of Siena, I-53100, Siena, SI, Italy
| | - Federico Corelli
- Department of Biotechnologies, Chemistry and Pharmacy, University of Siena, I-53100, Siena, SI, Italy
| | - Gian Luigi Gessa
- Neuroscience Institute, National Research Council of Italy, Section of Cagliari, I-09042 Monserrato, CA, Italy
| | - Giancarlo Colombo
- Neuroscience Institute, National Research Council of Italy, Section of Cagliari, I-09042 Monserrato, CA, Italy.
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Froger-Colléaux C, Castagné V. Effects of baclofen and raclopride on reinstatement of cocaine self-administration in the rat. Eur J Pharmacol 2016; 777:147-55. [DOI: 10.1016/j.ejphar.2016.03.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Revised: 03/01/2016] [Accepted: 03/02/2016] [Indexed: 12/13/2022]
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Van Skike CE, Maggio SE, Reynolds AR, Casey EM, Bardo MT, Dwoskin LP, Prendergast MA, Nixon K. Critical needs in drug discovery for cessation of alcohol and nicotine polysubstance abuse. Prog Neuropsychopharmacol Biol Psychiatry 2016; 65:269-87. [PMID: 26582145 PMCID: PMC4679525 DOI: 10.1016/j.pnpbp.2015.11.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Revised: 11/10/2015] [Accepted: 11/11/2015] [Indexed: 01/29/2023]
Abstract
Polysubstance abuse of alcohol and nicotine has been overlooked in our understanding of the neurobiology of addiction and especially in the development of novel therapeutics for its treatment. Estimates show that as many as 92% of people with alcohol use disorders also smoke tobacco. The health risks associated with both excessive alcohol consumption and tobacco smoking create an urgent biomedical need for the discovery of effective cessation treatments, as opposed to current approaches that attempt to independently treat each abused agent. The lack of treatment approaches for alcohol and nicotine abuse/dependence mirrors a similar lack of research in the neurobiology of polysubstance abuse. This review discusses three critical needs in medications development for alcohol and nicotine co-abuse: (1) the need for a better understanding of the clinical condition (i.e. alcohol and nicotine polysubstance abuse), (2) the need to better understand how these drugs interact in order to identify new targets for therapeutic development and (3) the need for animal models that better mimic this human condition. Current and emerging treatments available for the cessation of each drug and their mechanisms of action are discussed within this context followed by what is known about the pharmacological interactions of alcohol and nicotine. Much has been and will continue to be gained from studying comorbid alcohol and nicotine exposure.
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Affiliation(s)
- C E Van Skike
- Department of Pharmaceutical Sciences, University of Kentucky, Lexington, KY 40536, United States
| | - S E Maggio
- Department of Psychology, University of Kentucky, Lexington, KY 40536, United States
| | - A R Reynolds
- Department of Psychology, University of Kentucky, Lexington, KY 40536, United States
| | - E M Casey
- Department of Pharmaceutical Sciences, University of Kentucky, Lexington, KY 40536, United States
| | - M T Bardo
- Department of Psychology, University of Kentucky, Lexington, KY 40536, United States; Center for Drug Abuse and Research Translation, University of Kentucky, Lexington, KY 40536, United States; Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY 40536, United States
| | - L P Dwoskin
- Department of Pharmaceutical Sciences, University of Kentucky, Lexington, KY 40536, United States; Center for Drug Abuse and Research Translation, University of Kentucky, Lexington, KY 40536, United States
| | - M A Prendergast
- Department of Psychology, University of Kentucky, Lexington, KY 40536, United States; Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY 40536, United States
| | - K Nixon
- Department of Pharmaceutical Sciences, University of Kentucky, Lexington, KY 40536, United States; Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY 40536, United States.
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Jacobson LH, Sweeney FF, Kaupmann K, O’Leary OF, Gassmann M, Bettler B, Cryan JF. Differential roles of GABAB1 subunit isoforms on locomotor responses to acute and repeated administration of cocaine. Behav Brain Res 2016; 298:12-6. [DOI: 10.1016/j.bbr.2015.10.039] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Revised: 10/16/2015] [Accepted: 10/20/2015] [Indexed: 12/23/2022]
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Lorrai I, Maccioni P, Gessa GL, Colombo G. R(+)-Baclofen, but Not S(-)-Baclofen, Alters Alcohol Self-Administration in Alcohol-Preferring Rats. Front Psychiatry 2016; 7:68. [PMID: 27148096 PMCID: PMC4834306 DOI: 10.3389/fpsyt.2016.00068] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Accepted: 04/04/2016] [Indexed: 01/14/2023] Open
Abstract
Racemic baclofen [(±)-baclofen] has repeatedly been reported to suppress several -alcohol-motivated behaviors, including alcohol drinking and alcohol -self-administration, in rats and mice. Recent data suggested that baclofen may have bidirectional, stereospecific effects, with the more active enantiomer, R(+)-baclofen, suppressing alcohol intake and the less active enantiomer, S(-)-baclofen, stimulating alcohol intake in mice. The present study was designed to investigate whether this enantioselectivity of baclofen effects may also extend to the reinforcing properties of alcohol in rats. To this end, selectively bred Sardinian alcohol-preferring (sP) rats were initially trained to lever respond on a fixed ratio 4 (FR4) schedule of reinforcement for alcohol (15%, v/v) in daily 30-min sessions. Once responding had stabilized, rats were tested with vehicle, (±)-baclofen (3 mg/kg), R(+)-baclofen (0.75, 1.5, and 3 mg/kg), and S(-)-baclofen (6, 12, and 24 mg/kg) under the FR4 schedule of reinforcement. Treatment with 3 mg/kg (±)-baclofen reduced the number of lever responses for alcohol and estimated amount of self-administered alcohol by approximately 60% in comparison to vehicle treatment. R(+)-baclofen was approximately twice as active as (±)-baclofen: treatment with 1.5 mg/kg R(+)-baclofen decreased both variables to an extent similar to that of the decreasing effect of 3 mg/kg (±)-baclofen. Conversely, treatment with all doses of S(-)-baclofen failed to affect alcohol self administration. These results (a) confirm that non-sedative doses of (±)-baclofen effectively suppressed the reinforcing properties of alcohol in sP rats and (b) apparently do not extend to operant alcohol self-administration in sP rats the capability of S(-)-baclofen to stimulate alcohol drinking in mice.
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Affiliation(s)
- Irene Lorrai
- Neuroscience Institute, National Research Council of Italy - Cagliari Section , Monserrato , Italy
| | - Paola Maccioni
- Neuroscience Institute, National Research Council of Italy - Cagliari Section , Monserrato , Italy
| | - Gian Luigi Gessa
- Neuroscience Institute, National Research Council of Italy - Cagliari Section , Monserrato , Italy
| | - Giancarlo Colombo
- Neuroscience Institute, National Research Council of Italy - Cagliari Section , Monserrato , Italy
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Mayfield J, Blednov YA, Harris RA. Behavioral and Genetic Evidence for GIRK Channels in the CNS: Role in Physiology, Pathophysiology, and Drug Addiction. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2015; 123:279-313. [PMID: 26422988 DOI: 10.1016/bs.irn.2015.05.016] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
G protein-coupled inwardly rectifying potassium (GIRK) channels are widely expressed throughout the brain and mediate the inhibitory effects of many neurotransmitters. As a result, these channels are important for normal CNS function and have also been implicated in Down syndrome, Parkinson's disease, psychiatric disorders, epilepsy, and drug addiction. Knockout mouse models have provided extensive insight into the significance of GIRK channels under these conditions. This review examines the behavioral and genetic evidence from animal models and genetic association studies in humans linking GIRK channels with CNS disorders. We further explore the possibility that subunit-selective modulators and other advanced research tools will be instrumental in establishing the role of individual GIRK subunits in drug addiction and other relevant CNS diseases and in potentially advancing treatment options for these disorders.
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Affiliation(s)
- Jody Mayfield
- Waggoner Center for Alcohol and Addiction Research, The University of Texas at Austin, Austin, Texas, USA.
| | - Yuri A Blednov
- Waggoner Center for Alcohol and Addiction Research, The University of Texas at Austin, Austin, Texas, USA
| | - R Adron Harris
- Waggoner Center for Alcohol and Addiction Research, The University of Texas at Austin, Austin, Texas, USA
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Brown KM, Roy KK, Hockerman GH, Doerksen RJ, Colby DA. Activation of the γ-Aminobutyric Acid Type B (GABA(B)) Receptor by Agonists and Positive Allosteric Modulators. J Med Chem 2015; 58:6336-47. [PMID: 25856547 DOI: 10.1021/jm5018913] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Since the discovery of the GABA(B) agonist and muscle relaxant baclofen, there have been substantial advancements in the development of compounds that activate the GABA(B) receptor as agonists or positive allosteric modulators. For the agonists, most of the existing structure-activity data apply to understanding the role of substituents on the backbone of GABA as well as replacing the carboxylic acid and amine groups. In the cases of the positive allosteric modulators, the allosteric binding site(s) and structure-activity relationships are less well-defined; however, multiple classes of molecules have been discovered. The recent report of the X-ray structure of the GABA(B) receptor with bound agonists and antagonists provides new insights for the development of compounds that bind the orthosteric site of this receptor. From a therapeutic perspective, these data have enabled efforts in drug discovery in areas of addiction-related behavior, the treatment of anxiety, and the control of muscle contractility.
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Affiliation(s)
- Katie M Brown
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University , West Lafayette, Indiana 47907, United States
| | - Kuldeep K Roy
- Department of Biomolecular Sciences, University of Mississippi , University, Mississippi 38677, United States
| | - Gregory H Hockerman
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University , West Lafayette, Indiana 47907, United States
| | - Robert J Doerksen
- Department of Biomolecular Sciences, University of Mississippi , University, Mississippi 38677, United States
| | - David A Colby
- Department of Biomolecular Sciences, University of Mississippi , University, Mississippi 38677, United States
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