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Wang G, Peng S, Reyes Mendez M, Keramidas A, Castellano D, Wu K, Han W, Tian Q, Dong L, Li Y, Lu W. The TMEM132B-GABA A receptor complex controls alcohol actions in the brain. Cell 2024:S0092-8674(24)01024-9. [PMID: 39357522 DOI: 10.1016/j.cell.2024.09.006] [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: 09/10/2023] [Revised: 07/19/2024] [Accepted: 09/04/2024] [Indexed: 10/04/2024]
Abstract
Alcohol is the most consumed and abused psychoactive drug globally, but the molecular mechanisms driving alcohol action and its associated behaviors in the brain remain enigmatic. Here, we have discovered a transmembrane protein TMEM132B that is a GABAA receptor (GABAAR) auxiliary subunit. Functionally, TMEM132B promotes GABAAR expression at the cell surface, slows receptor deactivation, and enhances the allosteric effects of alcohol on the receptor. In TMEM132B knockout (KO) mice or TMEM132B I499A knockin (KI) mice in which the TMEM132B-GABAAR interaction is specifically abolished, GABAergic transmission is decreased and alcohol-induced potentiation of GABAAR-mediated currents is diminished in hippocampal neurons. Behaviorally, the anxiolytic and sedative/hypnotic effects of alcohol are markedly reduced, and compulsive, binge-like alcohol consumption is significantly increased. Taken together, these data reveal a GABAAR auxiliary subunit, identify the TMEM132B-GABAAR complex as a major alcohol target in the brain, and provide mechanistic insights into alcohol-related behaviors.
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Affiliation(s)
- Guohao Wang
- Synapse and Neural Circuit Research Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Shixiao Peng
- Synapse and Neural Circuit Research Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Miriam Reyes Mendez
- Synapse and Neural Circuit Research Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Angelo Keramidas
- Institute for Molecular Bioscience, The University of Queensland, 306 Carmody Road, St Lucia, Brisbane, QLD 4072, Australia
| | - David Castellano
- Synapse and Neural Circuit Research Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Kunwei Wu
- Synapse and Neural Circuit Research Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Wenyan Han
- Synapse and Neural Circuit Research Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Qingjun Tian
- Synapse and Neural Circuit Research Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Lijin Dong
- Genetic Engineering Core, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Yan Li
- Proteomics Core Facility, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Wei Lu
- Synapse and Neural Circuit Research Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA.
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Jones JD, Arout CA, Luba R, Murugesan D, Madera G, Gorsuch L, Schusterman R, Martinez S. The influence of drug class on reward in substance use disorders. Pharmacol Biochem Behav 2024; 240:173771. [PMID: 38670466 PMCID: PMC11162950 DOI: 10.1016/j.pbb.2024.173771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Revised: 03/26/2024] [Accepted: 04/16/2024] [Indexed: 04/28/2024]
Abstract
In the United States, the societal costs associated with drug use surpass $500 billion annually. The rewarding and reinforcing properties that drive the use of these addictive substances are typically examined concerning the neurobiological effects responsible for their abuse potential. In this review, terms such as "abuse potential," "drug," and "addictive properties" are used due to their relevance to the methodological, theoretical, and conceptual framework for understanding the phenomenon of drug-taking behavior and the associated body of preclinical and clinical literature. The use of these terms is not intended to cast aspersions on individuals with substance use disorders (SUD). Understanding what motivates substance use has been a focus of SUD research for decades. Much of this corpus of work has focused on the shared effects of each drug class to increase dopaminergic transmission within the central reward pathways of the brain, or the "reward center." However, the precise influence of each drug class on dopamine signaling, and the extent thereof, differs considerably. Furthermore, the aforementioned substances have effects on several neurobiological targets that mediate and modulate their addictive properties. The current manuscript sought to review the influence of drug class on the rewarding effects of each of the major pharmacological classes of addictive drugs (i.e., psychostimulants, opioids, nicotine, alcohol, and cannabinoids). Our review suggests that even subtle differences in drug effects can result in significant variability in the subjective experience of the drug, altering rewarding and other reinforcing effects. Additionally, this review will argue that reward (i.e., the attractive and motivational property of a stimulus) alone is not sufficient to explain the abuse liability of these substances. Instead, abuse potential is best examined as a function of both positive and negative reinforcing drug effects (i.e., stimuli that the subject will work to attain and stimuli that the subject will work to end or avoid, respectively). Though reward is central to drug use, the factors that motivate and maintain drug taking are varied and complex, with much to be elucidated.
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Affiliation(s)
- Jermaine D Jones
- Division on Substance Use Disorders, Department of Psychiatry, Columbia University Vagelos College of Physicians and Surgeons, 1051 Riverside Drive, New York, NY 10032, USA.
| | - Caroline A Arout
- Division on Substance Use Disorders, Department of Psychiatry, Columbia University Vagelos College of Physicians and Surgeons, 1051 Riverside Drive, New York, NY 10032, USA
| | - Rachel Luba
- Division on Substance Use Disorders, Department of Psychiatry, Columbia University Vagelos College of Physicians and Surgeons, 1051 Riverside Drive, New York, NY 10032, USA
| | - Dillon Murugesan
- CUNY School of Medicine, 160 Convent Avenue, New York, NY 10031, USA
| | - Gabriela Madera
- Division on Substance Use Disorders, Department of Psychiatry, Columbia University Vagelos College of Physicians and Surgeons, 1051 Riverside Drive, New York, NY 10032, USA
| | - Liam Gorsuch
- Department of Psychiatry, The University of British Columbia, 430-5950 University Blvd., Vancouver V6T 1Z3, BC, Canada
| | - Rebecca Schusterman
- Division on Substance Use Disorders, Department of Psychiatry, Columbia University Vagelos College of Physicians and Surgeons, 1051 Riverside Drive, New York, NY 10032, USA
| | - Suky Martinez
- Division on Substance Use Disorders, Department of Psychiatry, Columbia University Vagelos College of Physicians and Surgeons, 1051 Riverside Drive, New York, NY 10032, USA
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Uusi-Oukari M, Korpi ER. GABAergic mechanisms in alcohol dependence. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2024; 175:75-123. [PMID: 38555121 DOI: 10.1016/bs.irn.2024.03.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/02/2024]
Abstract
The target of alcohol's effect on the central nervous system has been sought for more than 50 years in the brain's GABA system. The behavioral and emotional effects of alcohol in humans and rodents are very similar to those of barbiturates and benzodiazepines, and GABAA receptors have been shown to be one of the sites of alcohol action. The mechanisms of GABAergic inhibition have been a hotspot of research but have turned out to be complex and controversial. Genetics support the involvement of some GABAA receptor subunits in the development of alcohol dependence and in alcohol use disorders (AUD). Since the effect of alcohol on the GABAA system resembles that of a GABAergic positive modulator, it may be possible to develop GABAergic drug treatments that could substitute for alcohol. The adaptation mechanisms of the GABA system and the plasticity of the brain are a big challenge for drug development: the drugs that act on GABAA receptors developed so far also may cause adaptation and development of additional addiction. Human polymorphisms should be studied further to get insight about how they affect receptor function, expression or other factors to make reasonable predictions/hypotheses about what non-addictive interventions would help in alcohol dependence and AUD.
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Affiliation(s)
- Mikko Uusi-Oukari
- Integrative Physiology and Pharmacology, Institute of Biomedicine, University of Turku, Turku, Finland
| | - Esa R Korpi
- Department of Pharmacology, Faculty of Medicine, University of Helsinki, Helsinki, Finland.
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Huh SY, Kim SG, Kim HK. Capsaicin Reduces Ethanol Consumption in C57BL/6 but not DBA/2 Mice. CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE 2022; 20:343-349. [PMID: 35466105 PMCID: PMC9048012 DOI: 10.9758/cpn.2022.20.2.343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 04/05/2021] [Accepted: 04/26/2021] [Indexed: 11/30/2022]
Abstract
Objective Capsaicin, the pungent analgesic substance of hot peppers which produces a burning sensation and pain is known to affect Substance P and central opioid activities. This experiment was designed to test the effect of capsaicin on alcohol consumption in C57BL/6 and DBA/2 mice. These two strains are known to differ in both their alcohol consumption and their endogenous opioid distribution and response to alcohol. It is hypothesized that this effect may be mediated by both increases Substance P and decreases beta-endorphin. Methods After i.p. administration of 0.01 and 0.001 mg/kg of capsaicin with a vehicle or the vehicle alone as the control for eight days in C57BL/6 and DBA/2 mice on limited access alcohol model, Capsaicin’s effects on 2-hour alcohol, 22-hours water, 24-hours food intake and body weight were studied. Results In this study, as expected, C57BL/6 mice drank significantly more alcohol than DBA/2 mice under baseline conditions. Capsaicin at both doses tested significantly reduced baseline alcohol consumption in C57BL/6 but not DBA/2 mice. These effects were selective for alcohol as capsaicin did not disrupt food or water consumption. Conclusion These results demonstrate that capsaicin differentially affects those mechanisms underlying alcohol consumption in two strains of mice known to differ in their preference for and consumption of alcohol. This effect is hypothesized to be related to differences in the response of the endogenous opioid system.
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Affiliation(s)
- Sung Young Huh
- Department of Psychiatry, Pusan National University Yangsan Hospital, Yangsan, Korea
- Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, Korea
| | - Sung-Gon Kim
- Department of Psychiatry, Pusan National University Yangsan Hospital, Yangsan, Korea
- Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, Korea
- Department of Psychiatry, Pusan National University School of Medicine, Yangsan, Korea
| | - Hyeon-Kyeong Kim
- Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, Korea
- Biochemical Research Institute, Pusan National University Yangsan Hospital, Yangsan, Korea
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Wang Z, Yang J, Ren Y, Yuan C, Wang Z. The effects of the grape varieties and the wine aging periods on the tannin profiles and the astringency perceptions of wines. JOURNAL OF FOOD MEASUREMENT AND CHARACTERIZATION 2022. [DOI: 10.1007/s11694-022-01355-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Nadia H, Fabienne M, Pierard C, Nicole M, Daniel B. Preventive Effects of Baclofen but Not Diazepam on Hippocampal Memory and Glucocorticoid Alterations After Prolonged Alcohol Withdrawal in Mice. Front Psychiatry 2022; 13:799225. [PMID: 35686185 PMCID: PMC9171496 DOI: 10.3389/fpsyt.2022.799225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Accepted: 03/22/2022] [Indexed: 11/13/2022] Open
Abstract
Our study aims at comparing in C57/Bl male mice, the impact of repeated injections of baclofen (an agonist of GABAB receptor) or diazepam (a benzodiazepine acting through a positive allosteric modulation of GABAA receptor) administered during the alcohol-withdrawal period on hippocampus-dependent memory impairments and brain regional glucocorticoid dysfunction after a short (1-week) or a long (4-week) abstinence. Hence, mice were submitted to a 6-month alcohol consumption (12%v/v) and were progressively withdrawn to water. Then, after a 1- or 4-weeks abstinence, they were submitted to a contextual memory task followed by measurements of corticosterone concentrations in the dorsal hippocampus (dHPC), the ventral hippocampus (vHPC) and the prefrontal cortex (PFC). Results showed that 1- and 4-week withdrawn mice exhibited a severe memory deficit and a significant abnormal rise of the test-induced increase of corticosterone (TICC) in the dHPC, as compared to water-controls or to mice still under alcohol consumption. Repeated daily systemic administrations of decreasing doses of diazepam (ranged from 0.5 to 0.12 mg/kg) or baclofen (ranged from 1.5 to 0.37 mg/kg) during the last 15 days of the withdrawal period, normalized both memory and TICC scores in the dHPC in 1-week withdrawn animals; in contrast, only baclofen-withdrawn mice showed both normal memory performance and TICC scores in the dHPC after a 4-week withdrawal period. In conclusion, the memory improvement observed in 4-week withdrawn mice administered with baclofen stem from the protracted normalization of glucocorticoid activity in the dHPC, a phenomenon encountered only transitorily in diazepam-treated withdrawn mice.
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Affiliation(s)
- Henkous Nadia
- Institut de Neurosciences Cognitives et Intégratives d'Aquitaine (INCIA), Université de Bordeaux, CNRS UMR 5287, Pessac, France
| | - Martins Fabienne
- Institut de Neurosciences Cognitives et Intégratives d'Aquitaine (INCIA), Université de Bordeaux, CNRS UMR 5287, Pessac, France
| | - Christophe Pierard
- Institut de Recherche Biomédicale des Armées (IRBA), Place Général Valérie André, Brétigny-sur-Orge, France
| | - Mons Nicole
- Institut de Neurosciences Cognitives et Intégratives d'Aquitaine (INCIA), Université de Bordeaux, CNRS UMR 5287, Pessac, France
| | - Beracochea Daniel
- Institut de Neurosciences Cognitives et Intégratives d'Aquitaine (INCIA), Université de Bordeaux, CNRS UMR 5287, Pessac, France
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Alcohol. Alcohol 2021. [DOI: 10.1016/b978-0-12-816793-9.00001-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Operant, oral alcohol self-administration: Sex differences in Sardinian alcohol-preferring rats. Alcohol 2019; 79:147-162. [PMID: 31029630 DOI: 10.1016/j.alcohol.2019.04.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 04/19/2019] [Accepted: 04/19/2019] [Indexed: 12/23/2022]
Abstract
Sardinian alcohol-preferring (sP) rats have been selectively bred, over almost 40 years, for high alcohol preference and consumption. sP rats have served as an animal model for more than 120 published studies. With very few exceptions, however, these studies have always employed male sP rats, and little is known about alcohol-related behaviors in female sP rats. The present study was designed to fill, at least in part, this gap. Accordingly, alcohol self-administration under the fixed ratio 4 schedule of reinforcement was compared among male, intact female, and ovariectomized female sP rats. Additionally, it was investigated whether i) estrous cycle influenced alcohol self-administration, and ii) alcohol self-administration in the three sP rat groups differed in sensitivity to pharmacological manipulation. Lever-responding for alcohol was steadily higher in male than intact and ovariectomized female sP rats; conversely, because of large sex differences in rat body weight, estimated amount of self-administered alcohol (in g/kg) did not differ among the three sP rat groups or occasionally was higher in intact female than male and ovariectomized female sP rats. Blood alcohol levels derived from self-administered alcohol i) did not differ among the three sP rat groups and ii) were positively correlated with the number of lever-responses for alcohol and the estimated amount of self-administered alcohol. Treatment with the opioid receptor antagonist, naloxone (0, 0.3, 1, and 3 mg/kg, i.p. [intraperitoneally]), and the positive allosteric modulator of the GABAB receptor, GS39783 (0, 25, 50, and 100 mg/kg, i.g. [intragastrically]), reduced alcohol self-administration with comparable potency and efficacy in the three sP rat groups. The impact of the estrous cycle on alcohol self-administration was relatively modest, limited to a tendency toward a reduction in the number of lever-responses for alcohol and the estimated amount of self-administered alcohol in estrus and metestrus. Together, these results provide the first characterization of alcohol-seeking and -taking behavior in female sP rats.
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Leggio GM, Di Marco R, Gulisano W, D'Ascenzo M, Torrisi SA, Geraci F, Lavanco G, Dahl K, Giurdanella G, Castorina A, Aitta-Aho T, Aceto G, Bucolo C, Puzzo D, Grassi C, Korpi ER, Drago F, Salomone S. Dopaminergic-GABAergic interplay and alcohol binge drinking. Pharmacol Res 2019; 141:384-391. [PMID: 30648615 DOI: 10.1016/j.phrs.2019.01.022] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 01/10/2019] [Accepted: 01/11/2019] [Indexed: 12/23/2022]
Abstract
The dopamine D3 receptor (D3R), in the nucleus accumbens (NAc), plays an important role in alcohol reward mechanisms. The major neuronal type within the NAc is the GABAergic medium spiny neuron (MSN), whose activity is regulated by dopaminergic inputs. We previously reported that genetic deletion or pharmacological blockade of D3R increases GABAA α6 subunit in the ventral striatum. Here we tested the hypothesis that D3R-dependent changes in GABAA α6 subunit in the NAc affect voluntary alcohol intake, by influencing the inhibitory transmission of MSNs. We performed in vivo and ex vivo experiments in D3R knockout (D3R -/-) mice and wild type littermates (D3R +/+). Ro 15-4513, a high affinity α6-GABAA ligand was used to study α6 activity. At baseline, NAc α6 expression was negligible in D3R+/+, whereas it was robust in D3R-/-; other relevant GABAA subunits were not changed. In situ hybridization and qPCR confirmed α6 subunit mRNA expression especially in the NAc. In the drinking-in-the-dark paradigm, systemic administration of Ro 15-4513 inhibited alcohol intake in D3R+/+, but increased it in D3R-/-; this was confirmed by intra-NAc administration of Ro 15-4513 and furosemide, a selective α6-GABAA antagonist. Whole-cell patch-clamp showed peak amplitudes of miniature inhibitory postsynaptic currents in NAc medium spiny neurons higher in D3R-/- compared to D3R+/+; Ro 15-4513 reduced the peak amplitude in the NAc of D3R-/-, but not in D3R+/+. We conclude that D3R-dependent enhanced expression of α6 GABAA subunit inhibits voluntary alcohol intake by increasing GABA inhibition in the NAc.
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Affiliation(s)
- Gian Marco Leggio
- Department of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, Catania, Italy
| | - Roberta Di Marco
- Department of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, Catania, Italy
| | - Walter Gulisano
- Department of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, Catania, Italy
| | - Marcello D'Ascenzo
- Institute of Human Physiology, Medical School, Università Cattolica, Rome, Italy; Fondazione Policlinico Universitario A. Gemelli IRCCS, Roma, Italia
| | - Sebastiano Alfio Torrisi
- Department of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, Catania, Italy
| | - Federica Geraci
- Department of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, Catania, Italy
| | - Gianluca Lavanco
- Department of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, Catania, Italy
| | - Kristiina Dahl
- Department of Pharmacology, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Giovanni Giurdanella
- Department of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, Catania, Italy
| | - Alessandro Castorina
- Department of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, Catania, Italy
| | - Teemu Aitta-Aho
- Department of Pharmacology, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Giuseppe Aceto
- Institute of Human Physiology, Medical School, Università Cattolica, Rome, Italy
| | - Claudio Bucolo
- Department of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, Catania, Italy
| | - Daniela Puzzo
- Department of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, Catania, Italy
| | - Claudio Grassi
- Institute of Human Physiology, Medical School, Università Cattolica, Rome, Italy; Fondazione Policlinico Universitario A. Gemelli IRCCS, Roma, Italia
| | - Esa R Korpi
- Department of Pharmacology, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Filippo Drago
- Department of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, Catania, Italy
| | - Salvatore Salomone
- Department of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, Catania, Italy.
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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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Barajaz AM, Kliethermes CL. An assessment of the utilization of the preclinical rodent model literature in clinical trials of putative therapeutics for the treatment of alcohol use disorders. Drug Alcohol Depend 2017; 181:77-84. [PMID: 29035708 DOI: 10.1016/j.drugalcdep.2017.09.022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Revised: 09/11/2017] [Accepted: 09/12/2017] [Indexed: 10/18/2022]
Abstract
OBJECTIVE Rodent models of Alcohol Use Disorders (AUD) are used extensively by preclinical researchers to develop new therapeutics for the treatment of AUD. Although these models play an important role in the development of novel, targeted therapeutics, their role in bringing therapeutics to clinical trials is unclear, as off-label use of existing medications not approved for the treatment of AUD is commonly seen in the clinic and clinical trials. METHOD In the current study, we used the Clinicaltrials.gov database to obtain a list of drugs that have been tested for efficacy in a clinical trial between 1997 and 2017. We then conducted a set of literature searches to determine which of the 98 unique drugs we identified had shown efficacy in a rodent model of an AUD prior to being tested in a clinical trial. RESULTS We found that slightly less than half of the drugs tested in clinical trials (48%) had shown prior efficacy in any rodent model of an AUD, while the remaining 52% of drugs were used off-label, or in some cases, following non-published studies. CONCLUSION This study raises the question of how clinical researchers incorporate results from preclinical studies in the decision to bring a drug to a clinical trial. Our results underscore the need for ongoing communication among preclinical and clinical researchers.
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Affiliation(s)
- Ashley M Barajaz
- Drake University, Department of Psychology and Neuroscience, 1344 27th Street, Des Moines, IA 50311, United States
| | - Christopher L Kliethermes
- Drake University, Department of Psychology and Neuroscience, 1344 27th Street, Des Moines, IA 50311, United States.
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Bell RL, Hauser SR, Liang T, Sari Y, Maldonado-Devincci A, Rodd ZA. Rat animal models for screening medications to treat alcohol use disorders. Neuropharmacology 2017; 122:201-243. [PMID: 28215999 PMCID: PMC5659204 DOI: 10.1016/j.neuropharm.2017.02.004] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2017] [Revised: 02/02/2017] [Accepted: 02/05/2017] [Indexed: 01/21/2023]
Abstract
The purpose of this review is to present animal research models that can be used to screen and/or repurpose medications for the treatment of alcohol abuse and dependence. The focus will be on rats and in particular selectively bred rats. Brief introductions discuss various aspects of the clinical picture, which provide characteristics of individuals with alcohol use disorders (AUDs) to model in animals. Following this, multiple selectively bred rat lines will be described and evaluated in the context of animal models used to screen medications to treat AUDs. Next, common behavioral tests for drug efficacy will be discussed particularly as they relate to stages in the addiction cycle. Tables highlighting studies that have tested the effects of compounds using the respective techniques are included. Wherever possible the Tables are organized chronologically in ascending order to describe changes in the focus of research on AUDs over time. In general, high ethanol-consuming selectively bred rats have been used to test a wide range of compounds. Older studies usually followed neurobiological findings in the selected lines that supported an association with a propensity for high ethanol intake. Most of these tests evaluated the compound's effects on the maintenance of ethanol drinking. Very few compounds have been tested during ethanol-seeking and/or relapse and fewer still have assessed their effects during the acquisition of AUDs. Overall, while a substantial number of neurotransmitter and neuromodulatory system targets have been assessed; the roles of sex- and age-of-animal, as well as the acquisition of AUDs, ethanol-seeking and relapse continue to be factors and behaviors needing further study. This article is part of the Special Issue entitled "Alcoholism".
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Affiliation(s)
- Richard L Bell
- Indiana University School of Medicine, Department of Psychiatry, Indianapolis, IN 46202, USA.
| | - Sheketha R Hauser
- Indiana University School of Medicine, Department of Psychiatry, Indianapolis, IN 46202, USA
| | - Tiebing Liang
- Indiana University School of Medicine, Department of Gastroenterology, Indianapolis, IN 46202, USA
| | - Youssef Sari
- University of Toledo, Department of Pharmacology, Toledo, OH 43614, USA
| | | | - Zachary A Rodd
- Indiana University School of Medicine, Department of Psychiatry, Indianapolis, IN 46202, USA
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Abstract
Alcoholism, more generically drug addiction, can be defined as a chronically relapsing disorder characterized by: (1) compulsion to seek and take the drug (alcohol); (2) loss of control in limiting (alcohol) intake; and (3) emergence of a negative emotional state (e.g., dysphoria, anxiety, irritability), reflecting a motivational withdrawal syndrome, when access to the drug (alcohol) is prevented (defined here as dependence). The compulsive drug seeking associated with alcoholism can be derived from multiple neuroadaptations, but the thesis argued here, derived largely from animal models, is that a key component involves decreased brain reward function, increased brain stress function, and compromised executive function, all of which contribute to the construct of negative reinforcement. Negative reinforcement is defined as drug taking that alleviates a negative emotional state. The negative emotional state that drives such negative reinforcement is hypothesized to derive from decreases in reward neurotransmission in the ventral striatum, such as decreased dopamine and opioid peptide function in the nucleus accumbens (ventral striatum), but also recruitment of brain stress systems, such as corticotropin-releasing factor (CRF), in the extended amygdala. Data from animal models that support this thesis show that acute withdrawal from chronic alcohol, sufficient to produce dependence, increases reward thresholds, increases anxiety-like responses, decreases dopamine system function, and increases extracellular levels of CRF in the central nucleus of the amygdala. CRF receptor antagonists also block excessive drug intake produced by dependence. Alcoholism also involves substantial neuroadaptations that persist beyond acute withdrawal and trigger relapse and deficits in cognitive function that can also fuel compulsive drinking. A brain stress response system is hypothesized to be activated by acute excessive drug intake, to be sensitized during repeated withdrawal, to persist into protracted abstinence, and to contribute to the compulsivity of alcoholism. Other components of brain stress systems in the extended amygdala that interact with CRF and may contribute to the negative motivational state of withdrawal include increases in norepinephrine function, increases in dynorphin activity, and decreases in neuropeptide Y. The combination of impairment of function in reward circuitry and recruitment of brain stress system circuitry provides a powerful neurochemical basis for the negative emotional states that are responsible for the negative reinforcement that drives the compulsivity of alcoholism.
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Affiliation(s)
- George F Koob
- Committee on the Neurobiology of Addictive Disorders, The Scripps Research Institute, La Jolla, CA, USA.
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Bell RL, Sable HJ, Colombo G, Hyytia P, Rodd ZA, Lumeng L. Animal models for medications development targeting alcohol abuse using selectively bred rat lines: neurobiological and pharmacological validity. Pharmacol Biochem Behav 2012; 103:119-55. [PMID: 22841890 PMCID: PMC3595005 DOI: 10.1016/j.pbb.2012.07.007] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2011] [Revised: 07/07/2012] [Accepted: 07/18/2012] [Indexed: 02/04/2023]
Abstract
The purpose of this review paper is to present evidence that rat animal models of alcoholism provide an ideal platform for developing and screening medications that target alcohol abuse and dependence. The focus is on the 5 oldest international rat lines that have been selectively bred for a high alcohol-consumption phenotype. The behavioral and neurochemical phenotypes of these rat lines are reviewed and placed in the context of the clinical literature. The paper presents behavioral models for assessing the efficacy of pharmaceuticals for the treatment of alcohol abuse and dependence in rodents, with particular emphasis on rats. Drugs that have been tested for their effectiveness in reducing alcohol/ethanol consumption and/or self-administration by these rat lines and their putative site of action are summarized. The paper also presents some current and future directions for developing pharmacological treatments targeting alcohol abuse and dependence.
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Affiliation(s)
- Richard L. Bell
- Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Helen J.K. Sable
- Department of Psychology, University of Memphis, Memphis, Tennessee, USA
| | - Giancarlo Colombo
- Neuroscience Institute, National Research Council of Italy, Section of Cagliari, Monserrato, Italy
| | - Petri Hyytia
- Institute of Biomedicine, University of Helsinki, Finland
| | - Zachary A. Rodd
- Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Lawrence Lumeng
- Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana, USA
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Neurosteroid Binding Sites on the GABA(A) Receptor Complex as Novel Targets for Therapeutics to Reduce Alcohol Abuse and Dependence. Adv Pharmacol Sci 2011; 2011:926361. [PMID: 22110489 PMCID: PMC3206502 DOI: 10.1155/2011/926361] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2011] [Accepted: 07/17/2011] [Indexed: 01/02/2023] Open
Abstract
Despite the prevalence of alcohol abuse and dependence in the US and Europe, there are only five approved pharmacotherapies for alcohol dependence. Moreover, these pharmacotherapeutic options have limited clinical utility. The purpose of this paper is to present pertinent literature suggesting that both alcohol and the neurosteroids interact at the GABAA receptor complex and that the neurosteroid sites on this receptor complex could serve as new targets for the development of novel therapeutics for alcohol abuse. This paper will also present data collected by our laboratory showing that one neurosteroid in particular, dehydroepiandrosterone (DHEA), decreases ethanol intake in rats under a variety of conditions. In the process, we will also mention relevant studies from the literature suggesting that both particular subtypes and subunits of the GABAA receptor play an important role in mediating the interaction of neurosteroids and ethanol.
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Hulin MW, Amato RJ, Winsauer PJ. GABA(A) receptor modulation during adolescence alters adult ethanol intake and preference in rats. Alcohol Clin Exp Res 2011; 36:223-33. [PMID: 21895721 DOI: 10.1111/j.1530-0277.2011.01622.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
BACKGROUND To address the hypothesis that GABA(A) receptor modulation during adolescence may alter the abuse liability of ethanol during adulthood, the effects of adolescent administration of both a positive and negative GABA(A) receptor modulator on adult alcohol intake and preference were assessed. METHODS Three groups of adolescent male rats received 12 injections of lorazepam (3.2 mg/kg), dehydroepiandrosterone (DHEA, 56 mg/kg), or vehicle on alternate days starting on postnatal day (PD) 35. After this time, the doses were increased to 5.6 and 100 mg/kg, respectively, for 3 more injections on alternate days. Subjects had access to 25 to 30 g of food daily, during the period of the first 6 injections, and 18 to 20 g thereafter. Food intake of each group was measured 60 minutes after food presentation, which occurred immediately after drug administration on injection days or at the same time of day on noninjection days. When subjects reached adulthood (PD 88), ethanol preference was determined on 2 separate occasions, an initial 3-day period and a 12-day period, in which increasing concentrations of ethanol were presented. During each preference test, intake of water, saccharin, and an ethanol/saccharin solution was measured after each 23-hour access period. RESULTS During adolescence, lorazepam increased 60-minute food intake, and this effect was enhanced under the more restrictive feeding schedule. DHEA had the opposite effect on injection days, decreasing food intake compared with noninjection days. In adulthood, the lorazepam-treated group preferred the 2 lowest concentrations of ethanol/saccharin more than saccharin alone compared with vehicle-treated subjects, which showed no preference for any concentration of ethanol/saccharin over saccharin. DHEA-treated subjects showed no preference among the 3 solutions. CONCLUSIONS These data demonstrate that GABA(A) receptor modulation during adolescence can alter intake and preference for ethanol in adulthood and highlights the importance of drug history as an important variable in the liability for alcohol abuse.
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Affiliation(s)
- Mary W Hulin
- Department of Pharmacology and Experimental Therapeutics, Louisiana State University Health Science Center, New Orleans, Louisiana, USA
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Abstract
A recent preliminary, single-case report suggested that baclofen not only reduces but may completely suppress craving in alcohol-dependent individuals. The current article summarizes the neurobiological basis of drug craving, and the pharmacological targets that have been shown to be involved in modulating such craving. The potential usefulness of agents that suppress craving is discussed. However, beyond individual case reports, no evidence is available to indicate that targeting a single neurobiological pathway will be sufficient to completely suppress craving in unselected individuals. Nevertheless, subgroups that carry specific characteristics associated with single receptor dysfunction might benefit from a targeted treatment. Further research is needed to enable clinicians to detect these subgroups.
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Affiliation(s)
- Falk Kiefer
- Department of Addictive Behaviour and Addiction Medicine, University of Heidelberg, Central Institute of Mental Health, Mannheim 68159, Germany.
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18
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Spanagel R. Alcoholism: A Systems Approach From Molecular Physiology to Addictive Behavior. Physiol Rev 2009; 89:649-705. [DOI: 10.1152/physrev.00013.2008] [Citation(s) in RCA: 491] [Impact Index Per Article: 32.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Alcohol consumption is an integral part of daily life in many societies. The benefits associated with the production, sale, and use of alcoholic beverages come at an enormous cost to these societies. The World Health Organization ranks alcohol as one of the primary causes of the global burden of disease in industrialized countries. Alcohol-related diseases, especially alcoholism, are the result of cumulative responses to alcohol exposure, the genetic make-up of an individual, and the environmental perturbations over time. This complex gene × environment interaction, which has to be seen in a life-span perspective, leads to a large heterogeneity among alcohol-dependent patients, in terms of both the symptom dimensions and the severity of this disorder. Therefore, a reductionistic approach is not very practical if a better understanding of the pathological processes leading to an addictive behavior is to be achieved. Instead, a systems-oriented perspective in which the interactions and dynamics of all endogenous and environmental factors involved are centrally integrated, will lead to further progress in alcohol research. This review adheres to a systems biology perspective such that the interaction of alcohol with primary and secondary targets within the brain is described in relation to the behavioral consequences. As a result of the interaction of alcohol with these targets, alterations in gene expression and synaptic plasticity take place that lead to long-lasting alteration in neuronal network activity. As a subsequent consequence, alcohol-seeking responses ensue that can finally lead via complex environmental interactions to an addictive behavior.
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Finn DA, Mark GP, Fretwell AM, Gililland KR, Strong MN, Ford MM. Reinstatement of ethanol and sucrose seeking by the neurosteroid allopregnanolone in C57BL/6 mice. Psychopharmacology (Berl) 2008; 201:423-33. [PMID: 18758755 PMCID: PMC4767154 DOI: 10.1007/s00213-008-1303-8] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2008] [Accepted: 08/09/2008] [Indexed: 01/01/2023]
Abstract
RATIONALE Recent work in our laboratory documented that the "sipper" method of operant ethanol self-administration produced high ethanol intake and blood ethanol concentrations as well as the typical extinction "burst" in responding under nonreinforced conditions in male C57BL/6 mice. However, the neurochemical basis for reinstatement of responding following extinction has not been examined in mice with this model. OBJECTIVES Based on findings that the GABAergic neurosteroid allopregnanolone (ALLO) significantly increased the consummatory phase of ethanol self-administration, the present study determined the effect of ALLO on the reinstatement of extinguished ethanol-seeking behavior and compared this effect to the reinstatement of responding for sucrose reward. MATERIALS AND METHODS Separate groups of male C57BL/6 mice were trained to lever press for access to a 10% ethanol (10E) or a 5% sucrose (5S) solution. A single response requirement of 16 presses (RR16) on an active lever resulted in 30 min of continuous access to the 10E or 5S solution. After the animals responded on the RR16 schedule for 14 weeks, mice were exposed to 30 min extinction sessions where responding had no scheduled consequence. Once responding stabilized below the preextinction baseline, mice received an intraperitoneal injection of ALLO (0, 3.2, 5.6, 10, or 17 mg/kg) 15 min prior to the extinction session in a within-subjects design. RESULTS ALLO produced a dose-dependent increase in responding under nonreinforced conditions in both the 10E and 5S groups. Additional work documented the ability of a conditioned cue light or a compound cue (light+lever retraction) to reinstate nonreinforced responding on the previously active lever. CONCLUSIONS These findings definitively show that conditioned cues and priming with ALLO are potent stimuli for reinstating both ethanol- and sucrose-seeking behavior in C57BL/6 mice.
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Affiliation(s)
- Deborah A. Finn
- VAMC Research, Oregon Health & Science University, Portland, OR 97239,Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR 97239
| | - Gregory P. Mark
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR 97239
| | | | - Katherine R. Gililland
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR 97239
| | - Moriah N. Strong
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR 97239
| | - Matthew M. Ford
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR 97239
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Abstract
Despite the generally held view that alcohol is an unspecific pharmacological agent, recent molecular pharmacology studies demonstrated that alcohol has only a few known primary targets. These are the NMDA, GABA(A), glycine, 5-hydroxytryptamine 3 (serotonin) and nicotinic ACh receptors as well as L-type Ca(2+) channels and G-protein-activated inwardly rectifying K(+) channels. Following this first hit of alcohol on specific targets in the brain, a second wave of indirect effects on a variety of neurotransmitter/neuropeptide systems is initiated that leads subsequently to the typical acute behavioural effects of alcohol, ranging from disinhibition to sedation and even hypnosis, with increasing concentrations of alcohol. Besides these acute pharmacodynamic aspects of alcohol, we discuss the neurochemical substrates that are involved in the initiation and maintenance phase of an alcohol drinking behaviour. Finally, addictive behaviour towards alcohol as measured by alcohol-seeking and relapse behaviour is reviewed in the context of specific neurotransmitter/neuropeptide systems and their signalling pathways. The activity of the mesolimbic dopaminergic system plays a crucial role during the initiation phase of alcohol consumption. Following long-term, chronic alcohol consumption virtually all brain neurotransmission seems to be affected, making it difficult to define which of the systems contributes the most to the transition from controlled to compulsive alcohol use. However, compulsive alcohol drinking is characterized by a decrease in the function of the reward neurocircuitry and a recruitment of antireward/stress mechanisms comes into place, with a hypertrophic corticotropin-releasing factor system and a hyperfunctional glutamatergic system being the most important ones.
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21
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Goodman A. Neurobiology of addiction. An integrative review. Biochem Pharmacol 2007; 75:266-322. [PMID: 17764663 DOI: 10.1016/j.bcp.2007.07.030] [Citation(s) in RCA: 224] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2007] [Revised: 07/22/2007] [Accepted: 07/23/2007] [Indexed: 02/08/2023]
Abstract
Evidence that psychoactive substance use disorders, bulimia nervosa, pathological gambling, and sexual addiction share an underlying biopsychological process is summarized. Definitions are offered for addiction and addictive process, the latter being the proposed designation for the underlying biopsychological process that addictive disorders are hypothesized to share. The addictive process is introduced as an interaction of impairments in three functional systems: motivation-reward, affect regulation, and behavioral inhibition. An integrative review of the literature that addresses the neurobiology of addiction is then presented, organized according to the three functional systems that constitute the addictive process. The review is directed toward identifying candidate neurochemical substrates for the impairments in motivation-reward, affect regulation, and behavioral inhibition that could contribute to an addictive process.
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Affiliation(s)
- Aviel Goodman
- Minnesota Institute of Psychiatry, 1347 Summit Avenue, St. Paul, MN 55105, USA.
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22
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Knapp DJ, Overstreet DH, Breese GR. Baclofen blocks expression and sensitization of anxiety-like behavior in an animal model of repeated stress and ethanol withdrawal. Alcohol Clin Exp Res 2007; 31:582-95. [PMID: 17374037 PMCID: PMC2864137 DOI: 10.1111/j.1530-0277.2007.00342.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Repeated exposures to forced ethanol diets (EDs) or restraint stress sensitize anxiety-like behavior during a future ethanol withdrawal. The present investigation assessed whether pretreatment of rats with agents targeting receptor systems thought to be important in treating relapse in alcoholic patients would prevent sensitization of anxiety-like behavior. METHODS Groups of rats were exposed to either (1) three 5-day cycles of ED with 2 days of withdrawal between cycles, (2) continuous ED, or (3) 5 days of ED in a single cycle preceded by 2 episodes of restraint stress 6 days apart. Drugs [baclofen, acamprosate, naloxone, lamotrigine, ifenprodil, dizocilpine (MK-801), CGS19755, diazepam, flumazenil, or 6-methyl-2-(phenylethynyl)pyridine] were given prophylactically during the first and second withdrawal periods only or, in separate baclofen experiments, acutely during the third withdrawal or during withdrawal from continuous ED. Baclofen administration preceded each stress session in the stress-withdrawal protocols. Anxiety-like behavior was assessed in the social interaction (SI) test 5 hours after the ethanol was removed or after 3 days of abstinence. RESULTS Baclofen (1.25, 2.5, and 5 mg/kg), flumazenil (5 mg/kg), and diazepam (1 mg/kg) blocked the reduction in SI induced by ethanol withdrawal. Among the drugs that alter glutamate function, only acamprosate (300 mg/kg) was effective. In the stress protocols, baclofen (5 mg/kg) given before each of the 2 restraint stress sessions before ethanol exposure or before stress during abstinence also attenuated SI deficits. CONCLUSIONS These findings suggest that GABAB and GABAA, but not glutamate or opioid mechanisms, are involved in adaptive changes associated with anxiety-like behavior induced by these repeated ethanol-withdrawal and stress-withdrawal paradigms. The lack of action of agents attenuating different aspects of glutamate function suggests that acamprosate's action is related to some other, as yet undetermined, mechanism.
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Affiliation(s)
- Darin J Knapp
- Department of Psychiatry, Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-7178, USA.
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Eiler WJA, June HL. Blockade of GABA(A) receptors within the extended amygdala attenuates D(2) regulation of alcohol-motivated behaviors in the ventral tegmental area of alcohol-preferring (P) rats. Neuropharmacology 2007; 52:1570-9. [PMID: 17451754 PMCID: PMC2743737 DOI: 10.1016/j.neuropharm.2007.03.001] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2006] [Revised: 02/27/2007] [Accepted: 03/01/2007] [Indexed: 11/19/2022]
Abstract
The dopamine (DA) mesolimbic pathway, which originates from DA cell bodies within the ventral tegmental area (VTA), has been shown by various studies to play a role in the mediation of various drugs of abuse including alcohol (EtOH). It has been suggested that the VTA's control of EtOH reward is mediated in part by the D2 receptors within the VTA. These receptors may be under the regulation of reciprocal GABAergic inputs from forebrain components of the mesolimbic path such as the nucleus accumbens (NAcc), a classic EtOH reward substrate, and the bed nucleus of the stria terminalis, a substrate recently implicated in EtOH reinforcement, forming a self-regulating feedback loop. To test this hypothesis, D2 regulation of EtOH self-administration (SA) was evaluated by the microinfusion of the D2 antagonist eticlopride into the VTA of P rats, which produced profound reductions in EtOH SA in the highest (20.0 and 40.0microg) doses tested in both BST/VTA and NAcc/VTA implanted P rats. To determine the role of GABA in the mediation of EtOH SA, a 32.0ng dose the non-selective GABA antagonist SR 95531 was microinfused into the BST producing no effect on responding for EtOH and into the NAcc which lead to a reduction in EtOH responding. Finally, the hypothesis that GABA innervation of the VTA from the mesolimbic forebrain may influence EtOH SA was examined by the simultaneous infusion of eticlopride (40.0microg) into the VTA and SR 95531 (32.0ng) into either the BST or NAcc. This combination infusion completely attenuated the reduction in EtOH SA observed with the 40.0microg dose of eticlopride alone in both groups of animals. These results suggest that while the D2 receptors within the VTA regulate EtOH-motivated behaviors, this is modulated by GABAergic input from the mesolimbic forebrain, specifically from the BST and NAcc.
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Affiliation(s)
- William JA Eiler
- Psychobiology of Addictions Program, Department of Psychology, Indiana University-Purdue University, Indianapolis, IN 46202
| | - Harry L. June
- Division of Alcohol and Drug Abuse, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD 21201
- Department of Pharmacology and Experimental Therapeutics, University of Maryland School of Medicine, Baltimore, MD 21201
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Leonard ST, Gerak LR, Gurkovskaya O, Moerschbaecher JM, Winsauer PJ. Effects of gamma-hydroxybutyric acid and flunitrazepam on ethanol intake in male rats. Pharmacol Biochem Behav 2007; 85:780-6. [PMID: 17208286 DOI: 10.1016/j.pbb.2006.11.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2006] [Revised: 11/15/2006] [Accepted: 11/20/2006] [Indexed: 11/19/2022]
Abstract
Both gamma-hydroxybutyric acid (GHB) and flunitrazepam are often used illicitly in combination with ethanol. Nevertheless, the effects that these and other drugs of abuse have on the reinforcing effects of ethanol remain inconclusive. To test the effects of GHB and flunitrazepam on contingent ethanol intake, twelve male Long-Evans rats were trained to orally consume ethanol using a saccharin-fading procedure. After training, all animals preferentially consumed ethanol instead of water at each of five ethanol concentrations (0-32%) when tested with a two-bottle preference test in the homecage. Animals then received a noncontingent dose of ethanol (0.32, 0.56, 1, and 1.33 g/kg), flunitrazepam (0.032, 0.1, and 0.32 mg/kg), or GHB (100, 180, 320, and 560 mg/kg) prior to each subject's daily access to ethanol (18% v/v). Noncontingent doses of ethanol decreased ethanol intake, however, the subjects consumed enough ethanol to maintain a consistent total ethanol dose in g/kg. Flunitrazepam did not affect ethanol intake at any dose tested, whereas GHB only affected intake at the highest dose (560 mg/kg), a dose that also produced sedation. These data suggest that there are perceptible or qualitative differences between GHB, flunitrazepam, and ethanol in terms of their capacity for modulating oral ethanol intake in outbred rats.
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Affiliation(s)
- Stuart T Leonard
- Department of Pharmacology and Experimental Therapeutics at Louisiana State University Health Sciences Center, 1901 Perdido St., New Orleans, LA 70112, USA.
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Besheer J, Lepoutre V, Mole B, Hodge CW. GABAA receptor regulation of voluntary ethanol drinking requires PKCepsilon. Synapse 2006; 60:411-9. [PMID: 16881070 PMCID: PMC2864065 DOI: 10.1002/syn.20314] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Protein kinase C (PKC) regulates a variety of neural functions, including ion channel activity, neurotransmitter release, receptor desensitization and differentiation. We have shown previously that mice lacking the epsilon-isoform of PKC (PKCepsilon) self-administer 75% less ethanol and exhibit supersensitivity to acute ethanol and allosteric positive modulators of GABA(A) receptors when compared with wild-type controls. The purpose of the present study was to examine involvement of PKCepsilon in GABA(A) receptor regulation of voluntary ethanol drinking. To address this question, PKCepsilon null-mutant and wild-type control mice were allowed to drink ethanol (10% v/v) vs. water on a two-bottle continuous access protocol. The effects of diazepam (nonselective GABA(A) BZ positive modulator), zolpidem (GABA(A) alpha1 agonist), L-655,708 (BZ-sensitive GABA(A) alpha5 inverse agonist), and flumazenil (BZ antagonist) were then tested on ethanol drinking. Ethanol intake (grams/kg/day) by wild-type mice decreased significantly after diazepam or zolpidem but increased after L-655,708 administration. Flumazenil antagonized diazepam-induced reductions in ethanol drinking in wild-type mice. However, ethanol intake by PKCepsilon null mice was not altered by any of the GABAergic compounds even though effects were seen on water drinking in these mice. Increased acute sensitivity to ethanol and diazepam, which was previously reported, was confirmed in PKCepsilon null mice. Thus, results of the present study show that PKCepsilon null mice do not respond to doses of GABA(A) BZ receptor ligands that regulate ethanol drinking by wild-type control mice. This suggests that PKCepsilon may be required for GABA(A) receptor regulation of chronic ethanol drinking.
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Affiliation(s)
- Joyce Besheer
- Bowles Center for Alcohol Studies, Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599
| | - Veronique Lepoutre
- Bowles Center for Alcohol Studies, Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599
| | - Beth Mole
- Bowles Center for Alcohol Studies, Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599
| | - Clyde W. Hodge
- Bowles Center for Alcohol Studies, Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599
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Sommer W, Hyytiä P, Kiianmaa K. The alcohol-preferring AA and alcohol-avoiding ANA rats: neurobiology of the regulation of alcohol drinking. Addict Biol 2006; 11:289-309. [PMID: 16961760 DOI: 10.1111/j.1369-1600.2006.00037.x] [Citation(s) in RCA: 118] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The AA (alko, alcohol) and ANA (alko, non-alcohol) rat lines were among the earliest rodent lines produced by bidirectional selection for ethanol preference. The purpose of this review is to highlight the strategies for understanding the neurobiological factors underlying differential alcohol-drinking behavior in these lines. Most early work evaluated functioning of the major neurotransmitter systems implicated in drug reward in the lines. No consistent line differences were found in the dopaminergic system either under baseline conditions or after ethanol challenges. However, increased opioidergic tone in the ventral striatum and a deficiency in endocannabinoid signaling in the prefrontal cortex of AA rats may comprise mechanisms leading to increased ethanol consumption. Because complex behaviors, such as ethanol drinking, are not likely to be controlled by single factors, system-oriented molecular-profiling strategies have been used recently. Microarray based expression analysis of AA and ANA brains and novel data-mining strategies provide a system biological view that allows us to formulate a hypothesis on the mechanism underlying selection for ethanol preference. Two main factors appear active in the selection: a recruitment of signal transduction networks, including mitogen-activated protein kinases and calcium pathways and involving transcription factors such as Creb, Myc and Max, to mediate ethanol reinforcement and plasticity. The second factor acts on the mitochondrion and most likely provides metabolic flexibility for alternative substrate utilization in the presence of low amounts of ethanol.
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Affiliation(s)
- Wolfgang Sommer
- Laboratory of Clinical and Translational Studies, NIAAA, National Institutes of Health, USA
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Korpi ER, Sinkkonen ST. GABA(A) receptor subtypes as targets for neuropsychiatric drug development. Pharmacol Ther 2005; 109:12-32. [PMID: 15996746 DOI: 10.1016/j.pharmthera.2005.05.009] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2005] [Accepted: 05/26/2005] [Indexed: 12/30/2022]
Abstract
The main inhibitory neurotransmitter system in the brain, the gamma-aminobutyric acid (GABA) system, is the target for many clinically used drugs to treat, for example, anxiety disorders and epilepsy and to induce sedation and anesthesia. These drugs facilitate the function of pentameric A-type GABA (GABA(A)) receptors that are extremely widespread in the brain and composed from the repertoire of 19 subunit variants. Modern genetic studies have found associations of various subunit gene polymorphisms with neuropsychiatric disorders, including alcoholism, schizophrenia, anxiety, and bipolar affective disorder, but these studies are still at their early phase because they still have failed to lead to validated drug development targets. Recent neurobiological studies on new animal models and receptor subunit mutations have revealed novel aspects of the GABA(A) receptors, which might allow selective targeting of the drug action in receptor subtype-selective fashion, either on the synaptic or extrasynaptic receptor populations. More precisely, the greatest advances have occurred in the clarification of the molecular and behavioral mechanisms of action of the GABA(A) receptor agonists already in the clinical use, such as benzodiazepines and anesthetics, rather than in the introduction of novel compounds to clinical practice. It is likely that these new developments will help to overcome the present problems of the chronic treatment with nonselective GABA(A) agonists, that is, the development of tolerance and dependence, and to focus the drug action on the neurobiologically and neuropathologically relevant substrates.
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Affiliation(s)
- Esa R Korpi
- Institute of Biomedicine, Pharmacology, Biomedicum Helsinki, P.O. Box 63 (Haartmaninkatu 8), FI-00014 University of Helsinki, Finland.
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Nguyen SA, Deleon CP, Malcolm RJ, Middaugh LD. Tiagabine reduces ethanol reward in C57BL/6 mice under acute and chronic administration regimens. Synapse 2005; 56:135-46. [PMID: 15765538 DOI: 10.1002/syn.20138] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Three experiments conducted on male C57BL/6 (B6) mice examined the effects of subcutaneous injections of the GABA uptake inhibitor, tiagabine, on appetitive (lever responding) and consummatory behavior (fountain contacts) of food restricted B6 mice for 12% ethanol and water rewards (Exp-1), and for food reward (Exp-2) delivered on a fixed ratio 4 schedule of reinforcement. Effects of acute injections (1,3,6,9 mgkg) and chronic administration (6,9 mg/kg) was examined. Exp-3 examined tiagabine effects on the voluntary consumption of continuously available 12% ethanol, and on the interactive effects of tiagabine and ethanol on motor activity of non-food restricted B6 mice. Results of Exp-1 and Exp-2 indicated that tiagabine can reduce appetitive behavior for ethanol reward with no evidence of tolerance upon chronic exposure. Tiagabine doses that reduced ethanol reward had less effect on behavior maintained by either water or food, and had no effect on motor activity. In contrast to the absence of tolerance to its effect on appetitive behavior for ethanol, mice rapidly developed tolerance to tiagabine's initial reduction of the consummatory response for ethanol (Exp-1), and the intake of freely available ethanol exceeded pre-tiagabine levels after several daily injections (Exp-3). Importantly, mice developed tolerance to tiagabine's sedative effect after three daily injections and its sedation was not enhanced when combined with ethanol, an effect consistent with the lack of a tiagabine + ethanol interaction previously reported for humans. The results of the experiments suggest that in addition to reducing alcohol withdrawal symptoms, tiagabine might also reduce the potency of ethanol-conditioned cues that drive appetitive behavior for ethanol.
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Affiliation(s)
- Shaun A Nguyen
- Center for Drug and Alcohol Programs, Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, South Carolina 29425, USA
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Ingman K, Sallinen J, Honkanen A, Korpi ER. Comparison of deramciclane to benzodiazepine agonists in behavioural activity of mice and in alcohol drinking of alcohol-preferring rats. Pharmacol Biochem Behav 2004; 77:847-54. [PMID: 15099931 DOI: 10.1016/j.pbb.2004.02.015] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2003] [Revised: 02/19/2004] [Accepted: 02/26/2004] [Indexed: 11/18/2022]
Abstract
Interactions between alcohol and traditional benzodiazepine anxiolytics hamper the treatment of alcoholism-related anxiety disorders. Serotonin 5-HT(2) receptor antagonists, such as deramciclane, are anxiolytic, and considering their pharmacological profile, they might benefit alcoholics with comorbid anxiety. We studied the effects of acute deramciclane (1, 3 and 10 mg/kg i.p.) on alcohol drinking of alcohol-preferring AA rats drinking 10% (vol/vol) ethanol solution in a 4-h limited-access paradigm. Thereafter, a 5-day repeated-treatment experiment was carried out, under corresponding test design, with deramciclane (3 mg/kg i.p.) as a test drug and midazolam (1 mg/kg i.p.) as a benzodiazepine reference compound. Deramciclane had no effect on alcohol consumption in either acute or repeated dosing study. Midazolam increased ethanol drinking, as expected, when administered on successive days. A modified functional observational battery (FOB) procedure was applied to study neurological, behavioural and autonomic effects induced by deramciclane (1-30 mg/kg po) and diazepam (1-30 mg/kg po) in mice at 30 min, 2 h and 4 h after dosing. Deramciclane had a mild dopamine D(2) receptor antagonism-like effect at the highest dose. The effects of diazepam were predictable, myorelaxation-induced motor impairment and anxiolysis-related hyperlocomotion in a novel environment being the characteristic features at the two highest doses. Deramciclane appears to be a safe and well-tolerated drug and we suggest that it might be useful in the treatment of anxiety in alcoholics.
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Affiliation(s)
- Kimmo Ingman
- Department of Pharmacology and Clinical Pharmacology, University of Turku, Itäinen Pitkäkatu 4B, FIN-20520 Turku, Finland.
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Wong G, Ovaska T, Korpi ER. Brain regional pharmacology of GABA(A) receptors in alcohol-preferring AA and alcohol-avoiding ANA rats. Addict Biol 2003; 1:263-72. [PMID: 12893465 DOI: 10.1080/1355621961000124876] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Compounds interacting with the GABA(A) receptor system modulate voluntary alcohol consumption in alcohol-preferring AA (Alko, Alcohol) rats. Therefore, we compared the central GABA(A) receptor pharmacology of the AA rats to that of their counterpart, alcohol-avoiding ANA (Alko, Non-Alcohol) rats with receptor autoradiography. Total flumazenil-sensitive [(3)H]Ro 15-4513 binding to the benzodiazepine site of GABA(A) receptor was slightly lower in the hippocampus, striate cortex and lateral hypothalamus of the AA than ANA rats. The proportions of zolpidem- and diazepam-sensitive components were similar in both rat lines. Basal picrotoxin-sensitive [(35)S]TBPS binding to the convulsant site of GABA(A) receptor was similar in most regions between the rat lines, but the up-modulation of the binding by 10 microM diazepam in the hippocampal, amygdaloid and entorhinal cortical areas was greater in the AA than ANA rats. These results do not reveal any general genetic defect in the GABA(A) receptors of AA or ANA rats, but the regional profile of the ligand binding differences between the lines, especially in the coupling of the benzodiazepine and chloride channel sites, suggests receptor subtype-specific changes in brain regions implicated in behavioural reward and anxiolysis.
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Affiliation(s)
- G Wong
- Department of Alcohol Research, National Public Health Institute, Helsinki, Finland
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31
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Blednov YA, Walker D, Alva H, Creech K, Findlay G, Harris RA. GABAA receptor alpha 1 and beta 2 subunit null mutant mice: behavioral responses to ethanol. J Pharmacol Exp Ther 2003; 305:854-63. [PMID: 12626647 DOI: 10.1124/jpet.103.049478] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Mice lacking either the alpha1 or beta 2 subunit of the GABAA receptor were tested for ethanol, saccharin, or quinine consumption, ethanol-conditioned place preference, ethanol-conditioned taste aversion, ethanol-simulated motor activity, and handling-induced seizures following chronic consumption of an ethanol liquid diet. The alpha1 null mutants showed decreased ethanol and saccharin consumption, increased aversion to ethanol, and a marked stimulation of motor activity after injection of ethanol. The beta 2 null mutants showed decreased consumption of saccharin and quinine, but not ethanol. Surprisingly, neither mutant showed marked changes in handling induced seizures before or after withdrawal of ethanol. The unique effects of deletion of these two GABAA receptor subunits on ethanol responses are discussed in terms of the distinct changes in different populations of GABAA receptors.
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Affiliation(s)
- Y A Blednov
- Waggoner Center for Alcohol and Addiction Research and Section of Neurobiology, University of Texas, Austin, TX 78712-1095, USA.
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Ingman K, Honkanen A, Hyytiä P, Huttunen MO, Korpi ER. Risperidone reduces limited access alcohol drinking in alcohol-preferring rats. Eur J Pharmacol 2003; 468:121-7. [PMID: 12742519 DOI: 10.1016/s0014-2999(03)01669-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
An atypical antipsychotic drug risperidone reduced ethanol drinking of ethanol-preferring Alko, Alcohol (AA) rats in a limited access paradigm. Its effect was transient at a dose known to preferentially antagonize the 5-HT(2) receptors (0.1 mg/kg, s.c.), but long-lasting when the dose was increased to 1.0 mg/kg that also blocks dopamine D(2) receptors. Risperidone also reduced dose-dependently locomotor activity and limited access saccharin intake of the AA rats, indicating that its effect on ethanol drinking was not selective. Risperidone at 0.1 mg/kg given before four successive daily ethanol-drinking sessions significantly reduced the ethanol intake. These data from an animal model of high ethanol intake suggest that risperidone should be tested in various populations of alcoholics for reducing ethanol consumption.
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Affiliation(s)
- Kimmo Ingman
- Department of Pharmacology and Clinical Pharmacology, University of Turku, Turku, Finland
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33
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Soini SL, Hyytiä P, Korpi ER. Brain regional mu-opioid receptor function in rat lines selected for differences in alcohol preference. Eur J Pharmacol 2002; 448:157-63. [PMID: 12144936 DOI: 10.1016/s0014-2999(02)01948-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
It has been suggested that opioid peptides play a role in the reinforcing effects of alcohol. The present study was designed to examine the function of the mu-opioid receptor system in rat lines selectively bred for alcohol preference (AA [Alko, Alcohol] rat line) and alcohol avoidance (ANA [Alko, Non-Alcohol] rat line). The functional coupling of mu-opioid receptors to G proteins was determined autoradiographically using Tyr-D-Ala-Gly-N(Me)Phe-Gly-ol-enkephalin-stimulated [35S]GTPgammaS binding in brain cryostat sections. The binding was significantly increased in the striatal patches and substantia nigra reticulata of the AA rats in comparison with that of the ANA rats. Within the AA rat line, there was a significant positive correlation between 3 mg/kg morphine-induced locomotor activity and activation of G-proteins in the substantia nigra compacta and nucleus accumbens core. These results of the selective breeding experiment suggest that brain region-specific differences in mu-opioid receptor function may correlate with innate differences in alcohol preference.
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Affiliation(s)
- Sanna L Soini
- Department of Pharmacology and Clinical Pharmacology, University of Turku, Itäinen Pitkäkatu 4B, FIN-20520 Turku, Finland.
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34
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Abstract
Ethanol has been shown to exert many of its biochemical and behavioral effects through an interaction with the gamma-aminobutyric acid (GABA) receptor system. This review focuses on a subset of studies that has used self-administration, as well as place and taste conditioning, procedures to investigate a role for the GABA(A) receptor system in modulating the rewarding and aversive effects of ethanol. Potential advantages and disadvantages of each procedure are also discussed. A significant amount of evidence supports the suggestion that GABA(A) receptors are important modulators of the motivational effects of ethanol, although most of the findings have been obtained from studies examining oral ethanol self-administration. Relatively fewer studies have investigated ethanol place and taste conditioning. All self-administration studies reviewed used rats, whereas most conditioning studies used mice. Results of these studies show that GABA(A) antagonists and inverse agonists reduce ethanol self-administration under limited-access conditions. The effect of GABA(A) agonists on ethanol self-administration is less clear due to their bidirectional effects. GABA(A) receptor antagonists have been shown to increase ethanol-induced conditioned place preference and conditioned taste aversion in mice and decrease ethanol-induced conditioned taste aversion in rats. Issues related to interpretation and integration of these findings across models and species are considered. The integration of data from self-administration and conditioning procedures is necessary to define the role of GABA(A) receptors in modulating the rewarding and aversive effects of ethanol and may lead to the development of pharmacotherapies that target GABA(A) receptors to treat alcoholism in human beings.
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Affiliation(s)
- Julia A Chester
- Department of Behavioral Neuroscience and Portland Alcohol Research Center, Oregon Health & Science University, Portland, OR 97201-3098, USA.
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35
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Schmitt U, Waldhofer S, Weigelt T, Hiemke C. Free-Choice Ethanol Consumption Under the Influence of GABAergic Drugs in Rats. Alcohol Clin Exp Res 2002. [DOI: 10.1111/j.1530-0277.2002.tb02561.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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36
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Lintunen M, Hyytiä P, Sallmen T, Karlstedt K, Tuomisto L, Leurs R, Kiianmaa K, Korpi ER, Panula P. Increased brain histamine in an alcohol‐preferring rat line, and modulation of ethanol consumption by H 3receptor mechanisms. FASEB J 2001. [DOI: 10.1096/fsb2fj000545fje] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - Petri Hyytiä
- Department of Mental Health and Alcohol Research National Public Health Institute Helsinki Finland
| | - Tina Sallmen
- Department of Biology Åbo Akademi University Turku Finland
| | - Kaj Karlstedt
- Department of Biology Åbo Akademi University Turku Finland
| | - Leena Tuomisto
- Department of Pharmacology and Toxicology University of Kuopio Kuopio Finland
| | - Rob Leurs
- Division of Medicinal Chemistry Leiden/Amsterdam Center for Drug Research Vrije Universiteit Amsterdam the Netherlands
| | - Kalervo Kiianmaa
- Department of Mental Health and Alcohol Research National Public Health Institute Helsinki Finland
| | - Esa R. Korpi
- Department of Pharmacology and Clinical Pharmacology University of Turku Turku Finland
| | - Pertti Panula
- Department of Biology Åbo Akademi University Turku Finland
- Department of Anatomy Institute of Biomedical Sciences, University of Helsinki Helsinki Finland
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37
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Mikolajczak P, Wiktorowicz K, Okulicz-Kozaryn I, Kostrzewa A, Kaminska E. Analysis of the distribution of peripheral blood lymphocyte subsets associated with chronic ethanol treatment in rats with a disturbed circadian cycle. Drug Alcohol Depend 2000; 60:303-9. [PMID: 11053765 DOI: 10.1016/s0376-8716(00)00116-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The present study examined the composition of lymphoid subsets in the peripheral blood of alcohol-preferring (PRF) and non-preferring (NPF) rats, in an experimental model of alcoholism involving the disruption of the circadian cycle. The absolute and relative number of lymphocytes in specific subsets (CD3, CD4, CD8, NK, CD45RA) were measured using the flow cytometry method. When control animals with a disrupted circadian cycle (KN) were compared with a normal diurnal cycle group (KD), it was noticed that this disruption led to an increase in the absolute number of lymphocytes T (CD3(+), CD4(+) and CD8(+) cells) and lymphocytes B (CD45RA(+)). After the period of time when the alcohol preference was seen, there was a change in response - as measured by the numbers and the percentage of lymphoid subsets in NPF rats - involving a lowering of NK and CD45RA(+) cells. It seems that these animals exhibit higher sensitivity towards prolonged ethanol intoxication. However, the PRF animals - for whom the analysed values were close to those of the control group (KN) - tolerated the toxic effects of ethanol better and this may be related to their genetic predisposition.
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Affiliation(s)
- P Mikolajczak
- Department of Pharmacology, Karol Marcinkowski University of Medical Sciences in Poznan, Fredry 10, 61-701, Poland
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38
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Söderpalm B, Svensson AI. Naloxone reverses disinhibitory/aggressive behavior in 5,7-DHT-lesioned rats; involvement of GABA(A) receptor blockade? Neuropharmacology 1999; 38:1851-9. [PMID: 10608280 DOI: 10.1016/s0028-3908(99)00076-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Effective medical treatment for impulsive aggression and several impulse control disorders is needed. Disinhibited, impulsive behavior of e.g. murderers, arsonists, suicidal patients, and patients suffering from antisocial personality or substance abuse disorders has been associated with signs of a deficiency in brain serotonin (5-HT) systems. Depletion of brain 5-HT consistently produces disinhibition and aggression also in experimental animals. The present series of experiments using a modified Vogel's conflict test indicates that the disinhibitory behavior of 5-HT-lesioned rats can be reversed by the commonly used opiate receptor antagonist naloxone at doses (0.1-5.0 mg/kg, s.c.) that do not significantly affect behavior in sham-lesioned controls. Moreover, this effect of naloxone, which resembles that previously observed after administration of negative modulators of gamma-aminobutyric acidA (GABA(A))/benzodiazepine receptor complexes, was reversed by a low inert dose (2.0 mg/kg, i.p.) of amobarbital. Furthermore, both naloxone (5.0 mg/kg, s.c.) and Ro 15-4513 (1.0 mg/kg, p.o.; a partial inverse agonist at benzodiazepine receptors) significantly decreased the number of attacks and the time spent in aggressive acts in 5,7-DHT-lesioned male residents. These results taken together with previous behavioral and neurochemical data suggest that the behavioral effects of naloxone observed here may involve an antagonistic action at brain gamma-aminobutyric acidA (GABA(A))/benzodiazepine receptor complexes. Thus, naloxone, its stable analogue naltrexone or other weak negative modulators of brain GABA(A)/benzodiazepine receptor complexes may represent a new pharmacological principle for the treatment of impulse control disorders.
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Affiliation(s)
- B Söderpalm
- Department of Pharmacology, Institute of Physiology and Pharmacology, Göteborg University, Sweden.
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39
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Söderpalm AH, Hansen S. Alcohol alliesthesia: food restriction increases the palatability of alcohol through a corticosterone-dependent mechanism. Physiol Behav 1999; 67:409-15. [PMID: 10497960 DOI: 10.1016/s0031-9384(99)00078-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The present article analyzed the dramatic increase in alcohol ingestion that is known to occur in laboratory rats subjected to food restriction. In the first experiment, we wished to know when during the day food restricted animals consume the "extra" alcohol ration. Determinations of ethanol drinking at 3-h intervals throughout the day revealed that although food-restricted animals drink much ethanol at all times of the day, they retain a definite daily rhythm such that peak intake occurs during the dark hours. The second experiment tested the hypothesis that chronic food restriction is accompanied by positive alliesthesia for the taste of alcohol. To answer this question, we employed the taste reactivity method to measure hedonic and aversive reactions to 6% ethanol as a function of nutritional status. It was found that two weeks of food restriction, which approximately doubled the voluntary intake of ethanol, was associated with a significant increase in the hedonic response elicited by intraoral infusions of ethanol. Alcohol also elicited fewer aversive responses in food restricted subjects. Because chronic food restriction increases adrenal corticosterone secretion, we used the corticosterone synthesis inhibitor metyrapone as a tool to assess the importance of adrenal corticosterone secretion for the increased palatability of alcohol observed during food restriction. The third experiment demonstrated that attenuation of corticosterone synthesis significantly reduced the hedonic taste reactions to alcohol observed in food-restricted rats; this drop in alcohol taste reward was accompanied by a nonsignificant increase in the aversive reaction to alcohol. The final experiment investigated the effect of prolonged exposure to exogenous corticosterone on the taste reactivity to ethanol in freely fed subjects. Adrenalectomized animals bearing corticosterone implants for 3 weeks found the taste of alcohol more pleasant than did intact or adrenalectomized rats implanted with blank pellets. Taken together, the present results suggest that food restriction is associated with an apparent increase in the sensory reward--positive alliesthesia--derived from alcohol; this effect appears to be mediated by increased adrenal corticosterone secretion.
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Affiliation(s)
- A H Söderpalm
- Department of Psychology, Göteborg University, Sweden
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40
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Chester JA, Cunningham CL. Baclofen alters ethanol-stimulated activity but not conditioned place preference or taste aversion in mice. Pharmacol Biochem Behav 1999; 63:325-31. [PMID: 10371663 DOI: 10.1016/s0091-3057(98)00253-6] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The present experiments examined the effects of the GABA(B) receptor agonist, baclofen, on the acquisition of ethanol-induced conditioned place preference (CPP) and conditioned taste aversion (CTA) in male DBA/2J mice. Mice in the CPP experiment received four pairings of ethanol (2g/kg) with a distinctive floor stimulus for a 5-min conditioning session (CS+ sessions). On intervening days (CS- sessions), mice received saline injections paired with a different floor type. On CS+ days, mice also received one of four doses of baclofen (0.0. 2.5, 5.0, or 7.5 mg/kg) 15 min before an injection of ethanol. For the preference test, all mice received saline injections, and were placed on a half-grid and half-hole floor for a 60-min session. Baclofen dose dependently reduced ethanol-stimulated activity, but did not alter the magnitude of ethanol-induced CPP at any dose. For the CTA experiment, mice were adapted to a 2-h per day water restriction regimen followed by five conditioning trials every 48 h. During conditioning trials, subjects received an injection of saline or baclofen (2.0 and 6.0 mg/kg) 15 min before injection of 2 g/kg ethanol or saline following 1-h access to a saccharin solution. Baclofen did not alter the magnitude of ethanol-induced CTA at any dose. In addition, baclofen alone did not produce a CTA. Overall, these studies show that activation of GABA(B) receptors with baclofen reduces ethanol-induced locomotor activation, but does not alter ethanol's rewarding or aversive effects in the CPP and CTA paradigms in DBA/2J mice.
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Affiliation(s)
- J A Chester
- Department of Behavioral Neuroscience, and Portland Alcohol Research Center, Oregon Health Sciences University, 97201-3098, USA
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41
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Soini SL, Honkanen A, Hyytiä P, Korpi ER. [3H]ethylketocyclazocine binding to brain opioid receptor subtypes in alcohol-preferring AA and alcohol-avoiding ANA rats. Alcohol 1999; 18:27-34. [PMID: 10386662 DOI: 10.1016/s0741-8329(98)00064-0] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
We measured brain regional patterns of [3H]ethylketocyclazocine binding to brain opioid receptors in ethanol-naive alcohol-preferring Alko, Alcohol (AA) and alcohol-avoiding Alko, Non-Alcohol (ANA) rats, by using quantitative autoradiography. This agonist ligand labels all opioid receptor subtypes. The proportions of mu- and delta-opioid receptor binding were evaluated by displacing the mu- and delta-opioid receptor components by the peptides Tyr-D-Ala-Gly-N(Me)Phe-Gly-ol (DAMGO, 100 nM) and Tyr-D-Pen-Gly-Phe-D-Pen (DPDPE, 100nM), respectively, the K-component being the naltrexone-sensitive binding left after removal of the above two components. The labeling patterns in the brains of the AA and ANA rats were consistent with the well-known distributions of the opioid receptor subtypes in nonselected rat strains and there was no major difference between the lines. The mu-opioid receptor binding was greater in the AA than ANA rats in several brain regions, most interestingly in the substantia nigra pars reticulata and striatal clusters with elevated shell/core ratios in the nucleus accumbens. The delta-opioid receptor binding did not differ between the lines, whereas the AA rats had more K-opioid receptors than the ANA rats in several brain regions, including limbic areas and basal ganglia. The observed results might indicate altered action of the opioidergic system on dopaminergic pathways in rats with differential alcohol preference.
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Affiliation(s)
- S L Soini
- Department of Pharmacology and Clinical Pharmacology, University of Turku, Finland
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42
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Maurel S, De Vry J, Schreiber R. Comparison of the effects of the selective serotonin-reuptake inhibitors fluoxetine, paroxetine, citalopram and fluvoxamine in alcohol-preferring cAA rats. Alcohol 1999; 17:195-201. [PMID: 10231167 DOI: 10.1016/s0741-8329(98)00046-9] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Clinical studies indicate that selective serotonin-reuptake inhibitors (SSRIs) may decrease alcohol intake and craving in particular subgroups of alcoholics. The aim of the present study was to compare the behavioral profile of various SSRIs in alcohol-preferring cAA rats, a genetic model of alcoholism. The effects of acute IP administration of fluoxetine (doses in mg/kg 1-10), citalopram (3-30), fluvoxamine (3-30) and paroxetine (1-10) on ethanol (EtOH) intake and preference, as well as food and total fluid intake, were determined in a 12-h access, water vs. 10% v/v EtOH two-bottle choice paradigm. Each compound reduced EtOH intake [Minimal Effective Doses (MEDs) 5, 10, 30 and 1 mg/kg for fluoxetine, citalopram, fluvoxamine, and paroxetine, respectively]. The degree of selectivity, that is, the extent to which reductions in EtOH intake could be separated from reductions in food and/or total fluid intake varied across the compounds. Thus, whereas EtOH intake was more markedly affected than food intake by fluoxetine, both parameters were equally affected by citalopram, and food intake was more markedly affected than EtOH intake by fluvoxamine and paroxetine. The anti-alcohol effect also differed with respect to specificity, that is, the degree to which effects on EtOH intake coincided with effects on EtOH preference. Whereas fluoxetine showed the highest level of specificity, followed by citalopram and fluvoxamine, the effect of paroxetine was nonspecific. The observed variation in the degree of selectivity and specificity of the anti-alcohol effect of SSRIs suggests that reductions in EtOH intake are not merely a consequence of a general suppressive effect on consummatory behavior. It is hypothesized that differences between the behavioral profiles of these compounds reflect a differential involvement of 5-HT receptor subtypes.
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Affiliation(s)
- S Maurel
- CNS Research, Bayer AG, Cologne, Germany
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43
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Kostowski W, Bieńkowski P. Discriminative stimulus effects of ethanol: neuropharmacological characterization. Alcohol 1999; 17:63-80. [PMID: 9895039 DOI: 10.1016/s0741-8329(98)00035-4] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Generally, compounds discriminated by animals possess psychotropic effects in animals and humans. As with many other drugs of abuse, strength of the ethanol discriminative stimulus is dose related. The majority of studies show that doses close to 1.0 g/kg are close to the minimum at which the discrimination can be learned easily. Substitution studies suggest that anxiolytic, sedative, atactic, and myorelaxant effects of ethanol all play an important role in the formation of its intercoeptive stimulus. Low doses of ethanol produce more excitatory cues, similar to amphetamine-like subjective stimuli, whereas higher doses produce rather sedative/hypnotic stimuli similar to those elicited by barbiturates. Substitution studies have shown that the complete substitution for ethanol may be exerted by certain GABA-mimetic drugs acting through different sites within the GABA(A)-benzodiazepine receptor complex (e.g., diazepam, pentobarbital, certain neurosteroids), gamma-hydroxybutyrate, and antagonists of the glutamate NMDA receptor. Among the NMDA receptor antagonists both noncompetitive (e.g., dizocilpine) and competitive antagonists (e.g., CGP 40116) are capable of substituting for ethanol. Further, some antagonists of strychnine-insensitive glycine modulatory sites among the NMDA receptor complex (e.g., L-701,324) dose-dependently substitute for the ethanol discriminative stimulus. On the other hand, neither GABA-benzodiazepine antagonists nor NMDA receptor agonists produce contradictory effects (i.e., reduce the ethanol discriminative stimulus). There is influence of a particular training dose of ethanol on the substitution pattern of different compounds. For example, 5-HT(1B/2C) agonists substitute for intermediate (1.0 g/kg) but not higher (2.0 g/kg) ethanol training doses. Discrimination studies with ethanol and drugs acting on NMDA and GABA receptors consistently indicate asymmetrical generalization. For example, ethanol is able to generalize to barbiturates and benzodiazepines, but neither the benzodiazepine nor barbiturate response generalizes to ethanol. Only a few drugs are able to antagonize, at least to some extent, the discriminative stimulus of ethanol (e.g., partial inverse GABA-benzodiazepine receptor antagonist Ro 15-4513 and the opioid antagonist naloxone). The ethanol stimulus effect may be increased (i.e., stronger recognition) by N-cholinergic drugs (nicotine), dopaminergic drugs (apomorphine), and 5-HT3 receptor agonists (m-chlorophenylbiguanide). Thus, the ethanol stimulus is composed of the several components, with the NMDA receptor and GABA(A) receptor complex being of particular importance. This suggests that a drug mixture may be more capable of substituting for ethanol (or block its stimulus) than a single compound. The ability of drugs to substitute for the ethanol discriminative stimulus is frequently, although not preclusively, associated with the reduction of voluntary ethanol consumption. The examples of positive correlation are gamma-hydroxybutyrate, possibly memantine and certain serotonergic drugs such as fluoxetine. However, it remains uncertain to what extent the discriminative stimulus of ethanol can be seen as relevant in the understanding of the complex mechanisms of dependence.
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Affiliation(s)
- W Kostowski
- Department of Pharmacology & Physiology of the Nervous System, Institute of Psychiatry & Neurology, Warsaw, Poland
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Ciccocioppo R, Ge J, Barnes NM, Cooper SJ. Central 5-HT3 receptors in P and in AA alcohol-preferring rats: An autoradiographic study. Brain Res Bull 1998; 46:311-5. [PMID: 9671260 DOI: 10.1016/s0361-9230(98)00016-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Considerable evidence exists for an involvement of serotonergic mechanisms in the control of alcohol consumption. In the present study, an extensive 5-hydroxytryptamine (5-HT3) receptor autoradiographical investigation was performed using two genetically selected rat strains, alcohol preferring (P) and Alko alcohol (AA) alcohol-preferring rats, as well as the corresponding alcohol nonpreferring (NP) and Alko nonalcohol (ANA) alcohol-nonpreferring rats. The aim was to determine if there are any differences in 5-HT3 binding levels that may illuminate mechanisms of alcohol preference in these animals. For quantitating 5-HT3 binding sites, [3H]S(-)zacopride (0.5 nM) was used. Non-specific binding was measured in the presence of granisetron 10(-6) M. The [3H]S(-)zacopride binding density was measured in two subregions of the amygdaloid nucleus, frontal cortex, piriform cortex, cingulate laminae, parietal anterior cortex, parietal medial cortex, hippocampus CA1, hippocampus CA3, and entorhinal cortex. In all the brain areas investigated, the results showed no differences between AA and ANA rats. In P rats, compared to NP controls, there was a 30% lower 5-HT3 binding level in the lateral nucleus and the posteromedial cortical nucleus of the amygdala. These findings suggest that the expression of high alcohol preference in genetically selected P and AA rats is not associated with a general alteration of central 5-HT3 receptors, although a lower 5-HT3 receptor level in the amygdala of P rats may contribute to the phenotype of this strain of animals.
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Affiliation(s)
- R Ciccocioppo
- Department of Pharmacological Sciences and Experimental Medicine, University of Camerino, Italy.
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Soini SL, Ovaska T, Honkanen A, Hyytiä P, Korpi ER. Brain opioid receptor binding of [3H]CTOP and [3H]naltrindole in alcohol-preferring AA and alcohol-avoiding ANA rats. Alcohol 1998; 15:227-32. [PMID: 9539380 DOI: 10.1016/s0741-8329(97)00125-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
We compared mu- and delta-opioid receptor distributions between the brains of alcohol-preferring Alko, Alcohol (AA) and alcohol-avoiding Alko, Non-Alcohol (ANA) rat lines, using autoradiography on brain sections with mu- and delta-opioid receptor antagonist ligands [3H]CTOP and [3H]naltrindole, respectively. The labeling patterns of the ligands were consistent with the known opioid receptor distributions in both rat lines and no major genetic differences were found between the lines. However, the binding density of mu- and delta-opioid receptors differed slightly in several brain areas: in the AA brain sections, limbic areas, such as hippocampus and amygdala, showed decreased mu- and delta-opioid receptor binding, whereas the striatal patches were larger and the substantia nigra showed higher binding density of the mu-receptors compared to the ANA sections. The small differences observed between the rat lines could be due to adaptations to altered endogenous opioid peptide levels or neural circuits, and associated with the differences in alcohol drinking or other behaviors.
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Affiliation(s)
- S L Soini
- Department of Pharmacology and Clinical Pharmacology, University of Turku, Finland
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Buczek Y, Le AD, Sellers EM, Tomkins DM. Effect of Pentylenetetrazole on Ethanol Intake, Ethanol Kinetics, and Social Behavior in Male Wistar Rats. Alcohol Clin Exp Res 1998. [DOI: 10.1111/j.1530-0277.1998.tb03670.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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47
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June HL, Torres L, Cason CR, Hwang BH, Braun MR, Murphy JM. The novel benzodiazepine inverse agonist RO19-4603 antagonizes ethanol motivated behaviors: neuropharmacological studies. Brain Res 1998; 784:256-75. [PMID: 9518641 DOI: 10.1016/s0006-8993(97)01380-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The novel imidazothienodiazepine inverse agonist RO19-4603 has been reported to attenuate EtOH intake in home cage drinking tests for at least 24 h post-drug administration after systemic administration. In the present study, selectively bred alcohol-preferring (P) rats were trained under a concurrent (FR4-FR4) operant schedule to press one lever for EtOH (10% v/v) and another lever for saccharin (0.05% or 0.75% g/v), then dose-response and timecourse effects of RO19-4603 were evaluated. Systemic RO19-4603 injections (0.0045-0.3 mg/kg; i.p.) profoundly reduced EtOH responding by as much as 97% of vehicle control on day 1. No effects were seen on saccharin responding except with the highest dose level (0.3 mg/kg). In a second experiment, microinjections of RO19-4603 (2-100 ng) directly into the nucleus accumbens (NA) suppressed EtOH responding on day 1 by as much as 53% of control: Control injections dorsal to the NA or ventral tegmental area did not significantly alter EtOH or saccharin responding. On day 2, rats in both experiments received no RO19-4603 treatments; however, all 7 of the i.p. doses, and all 3 of the intra-NA infusions continued to significantly suppress EtOH responding by 43-85% of vehicle control levels. In addition, i.p. injections of RO19-4603 produced a dose-dependent decrease in the slope of the cumulative record for EtOH responding, while concomitantly producing a dose-dependent increase in the slope for saccharin responding. RO19-4603's actions appear to be mediated via recognition sites at GABAA-BDZ receptors which regulate EtOH reinforcement, and not via mechanisms regulating ingestive behaviors. Based on recent in situ hybridization studies in our laboratory, we hypothesize that occupation of alpha4 containing GABAA diazepam insensitive (DI) receptors in the NA, may mediate in part, the RO19-4603 suppression of EtOH responding in EtOH-seeking P rats.
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Affiliation(s)
- H L June
- Department of Psychology, Indiana University School of Medicine, Indiana University-Purdue University, Indianapolis, IN 46202, USA
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Buczek Y, Tomkins DM, Le AD, Sellers EM. Opposite Effects of Ro 15-4513 on Acquisition and Maintenance of Ethanol Drinking Behavior in Male Wistar Rats. Alcohol Clin Exp Res 1997. [DOI: 10.1111/j.1530-0277.1997.tb04505.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Honkanen A, Ahtee L, Korpi ER. Voluntary alcohol drinking selectively accelerates dopamine release in the ventral striatum as reflected by 3-methoxytyramine levels. Brain Res 1997; 774:207-10. [PMID: 9452210 DOI: 10.1016/s0006-8993(97)81705-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Alcohol-preferring Alko, Alcohol (AA) rats with free access to food and water were taught to voluntarily consume 10% alcohol solution during 20-min sessions. After the drinking session, rats had elevated dopamine release (as reflected by 3-methoxytyramine concentrations) in the nucleus accumbens, olfactory tubercle, and caudate-putamen. When alcohol solution was replaced by plain water, dopamine release was increased only in the caudate-putamen, indicating selective activation of the mesolimbic dopaminergic pathway by alcohol.
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Affiliation(s)
- A Honkanen
- Department of Pharmacy, University of Helsinki, Finland.
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Petty F, Kramer GL, Davis LL, Fulton M, Adinoff B. Plasma gamma-aminobutyric acid (GABA) predicts outcome in patients with alcohol dependence. Prog Neuropsychopharmacol Biol Psychiatry 1997; 21:809-16. [PMID: 9278952 DOI: 10.1016/s0278-5846(97)00081-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
1. Previous studies have suggested that low plasma GABA levels (< or = 100 pmol/ml) may characterize a subset of patients with alcohol dependence. 2. In order to assess the clinical relevance of this biologic finding, the authors followed 49 alcohol dependent patients for up to 18 months following inpatient treatment. Treatment outcome was assessed by continuous abstinence and continued contact with research personnel. 3. Alcohol dependent patients with low plasma GABA had significantly better outcome than patients with plasma GABA in the normal control range (101-150 pmol/ml). 4. These findings suggest that plasma GABA measures may prove to be clinically useful in identifying alcohol dependent patients at risk for relapse.
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Affiliation(s)
- F Petty
- Veterans Affairs Medical Center, Dallas, TX, USA
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