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Moore CF, Zamarripa CA, Weerts EM. Oral Cannabidiol does not alter Alcohol Seeking and Self-Administration in Baboons. Drug Alcohol Depend 2023; 245:109829. [PMID: 36871377 PMCID: PMC10033431 DOI: 10.1016/j.drugalcdep.2023.109829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Revised: 02/16/2023] [Accepted: 02/17/2023] [Indexed: 03/07/2023]
Abstract
BACKGROUND The cannabinoid cannabidiol (CBD) is currently under investigation as a pharmacotherapy for alcohol use disorder. The aim of the present study was to examine whether acute and chronic treatment with pure CBD would decrease alcohol seeking and consumption behaviors or alter drinking patterns in male baboons with extensive histories of daily alcohol intake (1 g/kg/day). METHODS Seven male baboons self-administered oral alcohol (4% w/v) in a validated chained schedule of reinforcement (CSR) procedure that modeled periods of anticipation, seeking, and consumption. In Experiment 1, CBD (5-40 mg/kg) or vehicle (peanut oil, USP) was administered orally 15- or 90-minutes prior to the start of the session. In Experiment 2, oral doses of CBD (10-40 mg/kg) or vehicle were administered for 5 consecutive days during ongoing alcohol access under the CSR. In addition, behavioral observations were conducted to assess potential drug side effects (e.g., sedation, motor incoordination) following chronic CBD treatment immediately after the session and 24-hours after drug administration. RESULTS Across both experiments, baboons self-administered an average of 1 g/kg/day of alcohol under baseline conditions. Administration of acute or chronic CBD (150-1200 mg total CBD dose/day) that encompassed the purported therapeutic dose range did not significantly reduce alcohol seeking, self-administration or intake (g/kg). Drinking patterns (i.e., number of drinks/bouts, bout duration, nor interdrink interval) also were not altered. There were no observable behavioral disruptions following CBD treatment. CONCLUSIONS In sum, the current data do not support use of pure CBD as an effective pharmacotherapy to reduce ongoing excessive drinking.
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Affiliation(s)
| | - C Austin Zamarripa
- Behavioral Pharmacology Research Unit, Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, 5510 Nathan Shock Dr., Baltimore, MD 21224, USA
| | - Elise M Weerts
- Division of Behavioral Biology, USA; Behavioral Pharmacology Research Unit, Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, 5510 Nathan Shock Dr., Baltimore, MD 21224, USA.
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Abstract
Preclinical research over the past several decades has demonstrated a role for the γ-aminobutyric acidB (GABAB) receptor in alcohol use disorder (AUD). This chapter offers an examination of preclinical evidence on the role of the GABAB receptor on alcohol-related behaviors with a particular focus on the GABAB receptor agonist baclofen, for which effects have been most extensively studied, and positive allosteric modulators (PAMs) of the GABAB receptor. Studies employing rodent and non-human primate models have shown that activation of the GABAB receptor can reduce (1) stimulating and rewarding effects of alcohol; (2) signs of alcohol withdrawal in rats made physically dependent on alcohol; (3) acquisition and maintenance of alcohol drinking under a two-bottle alcohol versus water choice procedure; (4) alcohol intake under oral operant self-administration procedures; (5) motivational properties of alcohol measured using extinction and progressive ratio procedures; (6) the increase in alcohol intake after a period of alcohol abstinence (the alcohol deprivation effect or ADE); and (7) the ability of alcohol cues and stress to reinstate alcohol seeking when alcohol is no longer available. Baclofen and GABAB PAMs reduce the abovementioned behaviors across different preclinical models, which provides strong evidence for a significant role of the GABAB receptor in alcohol-related behaviors and supports development of medications targeting GABAB receptors for the treatment of AUD. This chapter highlights the value of examining mechanisms of alcohol-related behaviors across multiple animal models to increase the confidence in identification of new therapeutic targets.
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Affiliation(s)
- August F Holtyn
- Johns Hopkins University School of Medicine, Baltimore, MD, USA.
| | - Elise M Weerts
- Johns Hopkins University School of Medicine, Baltimore, MD, USA
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3
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Piacentino D, Grant-Beurmann S, Vizioli C, Li X, Moore CF, Ruiz-Rodado V, Lee MR, Joseph PV, Fraser CM, Weerts EM, Leggio L. Gut microbiome and metabolome in a non-human primate model of chronic excessive alcohol drinking. Transl Psychiatry 2021; 11:609. [PMID: 34853299 PMCID: PMC8636625 DOI: 10.1038/s41398-021-01728-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 10/27/2021] [Accepted: 11/05/2021] [Indexed: 02/08/2023] Open
Abstract
A relationship between the gut microbiome and alcohol use disorder has been suggested. Excessive alcohol use produces changes in the fecal microbiome and metabolome in both rodents and humans. Yet, these changes can be observed only in a subgroup of the studied populations, and reversal does not always occur after abstinence. We aimed to analyze fecal microbial composition and function in a translationally relevant baboon model of chronic heavy drinking that also meets binge criteria (drinking too much, too fast, and too often), i.e., alcohol ~1 g/kg and blood alcohol levels (BALs) ≥ 0.08 g/dL in a 2-hour period, daily, for years. We compared three groups of male baboons (Papio anubis): L = Long-term alcohol drinking group (12.1 years); S = Short-term alcohol drinking group (2.7 years); and C = Control group, drinking a non-alcoholic reinforcer (Tang®) (8.2 years). Fecal collection took place during 3 days of Drinking (D), followed by a short period (3 days) of Abstinence (A). Fecal microbial alpha- and beta-diversity were significantly lower in L vs. S and C (p's < 0.05). Members of the commensal families Lachnospiraceae and Prevotellaceae showed a relative decrease, whereas the opportunistic pathogen Streptococcus genus showed a relative increase in L vs. S and C (p's < 0.05). Microbiota-related metabolites of aromatic amino acids, tricarboxylic acid cycle, and pentose increased in L vs. S and C (FDR-corrected p < 0.01), with the latter two suggesting high energy metabolism and enhanced glycolysis in the gut lumen in response to alcohol. Consistent with the long-term alcohol exposure, mucosal damage and oxidative stress markers (N-acetylated amino acids, 2-hydroxybutyrate, and metabolites of the methionine cycle) increased in L vs. S and C (FDR-corrected p < 0.01). Overall, S showed few differences vs. C, possibly due to the long-term, chronic alcohol exposure needed to alter the normal gut microbiota. In the three groups, the fecal microbiome barely differed between conditions D and A, whereas the metabolome shifted in the transition from condition D to A. In conclusion, changes in the fecal microbiome and metabolome occur after significant long-term excessive drinking and are only partially affected by acute forced abstinence from alcohol. These results provide novel information on the relationship between the fecal microbiome and metabolome in a controlled experimental setting and using a unique non-human primate model of chronic excessive alcohol drinking.
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Affiliation(s)
- Daria Piacentino
- grid.94365.3d0000 0001 2297 5165Clinical Psychoneuroendocrinology and Neuropsychopharmacology Section, Translational Addiction Medicine Branch, National Institute on Drug Abuse Intramural Research Program and National Institute on Alcohol Abuse and Alcoholism Division of Intramural Clinical and Biological Research, National Institutes of Health, 251 Bayview Blvd, Baltimore, MD 21224 USA ,grid.94365.3d0000 0001 2297 5165Center on Compulsive Behaviors, National Institutes of Health, 10 Center Dr, Bethesda, MD 20892 USA
| | - Silvia Grant-Beurmann
- grid.411024.20000 0001 2175 4264Institute for Genome Sciences, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD USA
| | - Carlotta Vizioli
- grid.420085.b0000 0004 0481 4802Sensory Science and Metabolism Unit, National Institute on Alcohol Abuse and Alcoholism Division of Intramural Clinical and Biological Research and National Institute of Nursing Research Division of Intramural Research, 10 Center Dr, Bethesda, MD 20892 USA
| | - Xiaobai Li
- grid.94365.3d0000 0001 2297 5165Biostatistics and Clinical Epidemiology Services, National Institutes of Health, Bethesda, MD USA
| | - Catherine F. Moore
- grid.21107.350000 0001 2171 9311Division of Behavioral Biology, Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Nathan Shock Drive, Baltimore, MD 21224 USA
| | - Victor Ruiz-Rodado
- grid.94365.3d0000 0001 2297 5165Neuro-Oncology Branch, National Cancer Institute, National Institutes of Health, 10 Center Dr, Bethesda, MD 20892 USA
| | - Mary R. Lee
- grid.94365.3d0000 0001 2297 5165Clinical Psychoneuroendocrinology and Neuropsychopharmacology Section, Translational Addiction Medicine Branch, National Institute on Drug Abuse Intramural Research Program and National Institute on Alcohol Abuse and Alcoholism Division of Intramural Clinical and Biological Research, National Institutes of Health, 251 Bayview Blvd, Baltimore, MD 21224 USA
| | - Paule V. Joseph
- grid.420085.b0000 0004 0481 4802Sensory Science and Metabolism Unit, National Institute on Alcohol Abuse and Alcoholism Division of Intramural Clinical and Biological Research and National Institute of Nursing Research Division of Intramural Research, 10 Center Dr, Bethesda, MD 20892 USA
| | - Claire M. Fraser
- grid.411024.20000 0001 2175 4264Institute for Genome Sciences, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD USA
| | - Elise M. Weerts
- grid.21107.350000 0001 2171 9311Division of Behavioral Biology, Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Nathan Shock Drive, Baltimore, MD 21224 USA
| | - Lorenzo Leggio
- Clinical Psychoneuroendocrinology and Neuropsychopharmacology Section, Translational Addiction Medicine Branch, National Institute on Drug Abuse Intramural Research Program and National Institute on Alcohol Abuse and Alcoholism Division of Intramural Clinical and Biological Research, National Institutes of Health, 251 Bayview Blvd, Baltimore, MD, 21224, USA. .,Center on Compulsive Behaviors, National Institutes of Health, 10 Center Dr, Bethesda, MD, 20892, USA. .,Medication Development Program, National Institute on Drug Abuse Intramural Research Program, National Institutes of Health, 251 Bayview Blvd, Baltimore, MD, 21224, USA. .,Center for Alcohol and Addiction Studies, Department of Behavioral and Social Sciences, Brown University School of Public Health, 121 South Main Street, Providence, RI, USA. .,Division of Addiction Medicine, Department of Medicine, Johns Hopkins University School of Medicine, 733 N Broadway, Baltimore, MD, 21205, USA. .,Department of Neuroscience, Georgetown University Medical Center, 3970 Reservoir Rd NW, Washington, DC, 20007, USA.
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Holtyn AF, Davis CM, Weerts EM. Development of a novel alcohol and nicotine concurrent access (ANCA) self-administration procedure in baboons. Drug Alcohol Depend 2020; 206:107665. [PMID: 31801108 PMCID: PMC6980761 DOI: 10.1016/j.drugalcdep.2019.107665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 09/03/2019] [Accepted: 09/22/2019] [Indexed: 10/25/2022]
Abstract
BACKGROUND Self-administration of either alcohol or nicotine under single-access conditions has been studied extensively in laboratory animals. Relatively few studies have examined the co-use of these substances, even though alcohol and nicotine use and abuse commonly co-occur in humans. The objectives of this study were to develop a baboon model of concurrent alcohol and nicotine self-administration, and examine effects of varenicline on alcohol and nicotine co-use. METHODS In Experiment 1, five male baboons were trained to self-administer drinks of alcohol (4% w/v) and injections of nicotine (0.032-0.1 mg/kg) under single-access and then concurrent-access conditions, and intake of alcohol (g/kg) and nicotine (mg/kg) was compared under single- and concurrent-access conditions. In Experiment 2, three male baboons self-administered drinks of alcohol (4% w/v) and injections of nicotine (0.056 mg/kg) under concurrent-access conditions. Pretreatment with varenicline (0.32-1.0 mg/kg, s.c.) or an equal volume of its vehicle before concurrent-access sessions was repeated for 5 consecutive days. RESULTS Self-administration of nicotine and alcohol was successfully established under both single- and concurrent-access conditions that produced reliable levels of voluntary alcohol and nicotine intake. Co-self-administration of both drugs produced levels of intake similar to that produced by each drug alone. Varenicline significantly reduced intake of both alcohol and nicotine when compared to the vehicle condition. CONCLUSIONS This baboon model provides a valuable tool for further investigation of the behavioral and pharmacological mechanisms involved in co-use of nicotine and alcohol. A single pharmacotherapeutic agent (e.g., varenicline) may be useful in treating nicotine and alcohol co-use.
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Holtyn AF, Weerts EM. Evaluation of mifepristone effects on alcohol-seeking and self-administration in baboons. Exp Clin Psychopharmacol 2019; 27:227-235. [PMID: 30570274 PMCID: PMC6727199 DOI: 10.1037/pha0000246] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Mifepristone, a type II glucocorticoid receptor antagonist, is under investigation as a potential pharmacotherapy for alcohol use disorder. This study examined effects of chronic administration of mifepristone on alcohol-seeking and self-administration in large nonhuman primates. Adult baboons (n = 5) self-administered alcohol 7 days/week under a chained schedule of reinforcement (CSR). The CSR comprised 3 components in which distinct cues were paired with different schedule requirements, with alcohol available for self-administration only in the final component, to model different phases of alcohol anticipation, seeking, and consumption. Under baseline conditions, baboons self-administered an average of 1g/kg/day of alcohol in the self-administration period. Mifepristone (10, 20, and 30 mg/kg) or vehicle was administered orally 30 min before each CSR session for 7 consecutive days. In a separate group of baboons (n = 5) acute doses of mifepristone (10, 20, and 30 mg/kg) were administered, and blood samples were collected over 72 hr to examine mifepristone pharmacokinetics. Some samples also were collected from the baboons that self-administered alcohol under the CSR after the chronic mifepristone condition. Mifepristone did not alter alcohol-seeking or self-administration under the CSR when compared with the vehicle condition. Mifepristone pharmacokinetics were nonlinear, and appear to be capacity limited. In sum, mifepristone did not reduce alcohol-maintained behaviors when administered to baboons drinking 1g/kg daily. (PsycINFO Database Record (c) 2019 APA, all rights reserved).
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Affiliation(s)
- August F. Holtyn
- Johns Hopkins University School of Medicine, 5200 Eastern Ave, Baltimore, MD 21224, USA
| | - Elise M. Weerts
- Johns Hopkins University School of Medicine, 5510 Nathan Shock Dr, Baltimore, MD 21224, USA
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6
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McCaul ME, Wand GS, Weerts EM, Xu X. A paradigm for examining stress effects on alcohol-motivated behaviors in participants with alcohol use disorder. Addict Biol 2018; 23:836-845. [PMID: 28419649 PMCID: PMC5645206 DOI: 10.1111/adb.12511] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Revised: 03/07/2017] [Accepted: 03/09/2017] [Indexed: 11/30/2022]
Abstract
Although epidemiological research has shown an increase in drinking following stressors and trauma, limited paradigms have been validated to study the relationship between stress and drinking in the human laboratory. The current study developed a progressive ratio (PR) operant procedure to examine the effects of psychosocial stress on alcohol craving and several alcohol-motivated behaviors in persons with alcohol use disorder. Current heavy, nontreatment-seeking drinkers (N = 30) were media-recruited and completed a comprehensive assessment of recent drinking, mood and health. Participants were admitted to the clinical research unit and underwent 4-day, physician-monitored alcohol abstinence. On days 4 and 5, participants underwent the Trier Social Stress Test or a neutral session in random order followed by the alcohol-motivated response (AMR) procedure in which subjects worked for money or alcohol under a PR operant procedure. Subjects received earned money vouchers or alcohol at the conclusion of the session. The Trier Social Stress Test increased alcohol craving and rate of responding and decreased the number of changeovers between alcohol versus money reinforcers on the PR schedule. There was a positive relationship between alcohol craving and drinks earned during the stress session. This novel paradigm provides an experimental platform to examine motivation to drink without confounding by actual alcohol ingestion during the work session, thereby setting the stage for future studies of alcohol interventions.
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Affiliation(s)
- Mary E. McCaul
- Department of Psychiatry and Behavioral SciencesThe Johns Hopkins University School of MedicineBaltimoreMDUSA
| | - Gary S. Wand
- Department of MedicineThe Johns Hopkins University School of MedicineBaltimoreMDUSA
| | - Elise M. Weerts
- Department of Psychiatry and Behavioral SciencesThe Johns Hopkins University School of MedicineBaltimoreMDUSA
| | - Xiaoqiang Xu
- Department of Psychiatry and Behavioral SciencesThe Johns Hopkins University School of MedicineBaltimoreMDUSA
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7
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Holtyn AF, Kaminski BJ, Weerts EM. Baclofen and naltrexone effects on alcohol self-administration: Comparison of treatment initiated during abstinence or ongoing alcohol access in baboons. Drug Alcohol Depend 2017; 179:47-54. [PMID: 28753481 PMCID: PMC5599358 DOI: 10.1016/j.drugalcdep.2017.06.019] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Revised: 06/09/2017] [Accepted: 06/12/2017] [Indexed: 12/20/2022]
Abstract
BACKGROUND Baclofen, a GABAB receptor agonist, is under investigation as a pharmacotherapy for alcohol use disorder. Treatment with a pharmacotherapeutic can be initiated during alcohol abstinence or active drinking, which may influence treatment outcomes. This study examined whether baclofen treatment initiated and maintained during alcohol abstinence would reduce alcohol seeking and self-administration upon return to alcohol access, and whether effects differed from treatment initiated and maintained during ongoing alcohol access. Naltrexone was tested under similar conditions for comparison. METHODS Five baboons self-administered alcohol under a three-component chained schedule of reinforcement that modeled periods of anticipation (Component 1), seeking (Component 2), and consumption (Component 3). Alcohol was only available in Component 3. In Experiment 1, baclofen (0.1-1.8mg/kg) or naltrexone (1.0-5.6mg/kg) was administered daily beginning on the first day of a 5-day abstinence period and treatment was continued for 5days of alcohol access. In Experiment 2, selected doses of both drugs were administered during ongoing alcohol access. RESULTS When treatment was initiated during alcohol abstinence, baclofen and naltrexone did not significantly reduce total alcohol intake (g/kg) or alcohol seeking. In comparison, when treatment was initiated during ongoing alcohol access, both baclofen (1.8mg/kg) and naltrexone (3.2 and 5.6mg/kg) significantly reduced total alcohol intake (g/kg). Naltrexone (5.6mg/kg), but not baclofen, significantly reduced alcohol seeking. CONCLUSIONS Initiation of baclofen treatment (or other alcohol use disorder treatments) during abstinence or active drinking may be an important factor in influencing efficacy and appropriate dose selection.
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Holtyn AF, Tiruveedhula VVNPB, Stephen MR, Cook JM, Weerts EM. Effects of the benzodiazepine GABA A α1-preferring antagonist 3-isopropoxy-β-carboline hydrochloride (3-ISOPBC) on alcohol seeking and self-administration in baboons. Drug Alcohol Depend 2017; 170:25-31. [PMID: 27865151 PMCID: PMC5183547 DOI: 10.1016/j.drugalcdep.2016.10.036] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Revised: 10/28/2016] [Accepted: 10/28/2016] [Indexed: 01/09/2023]
Abstract
BACKGROUND The major inhibitory neurotransmitter, gamma-aminobutyric acid (GABA), modulates many of the behavioral effects of alcohol, including sedation, tolerance, and withdrawal. The α1 subunit of the benzodiazepine GABAA receptor is the most widely expressed alpha subunit in the brain, and has been implicated in the reinforcing- and abuse-related effects of alcohol. The aim of the present study was to examine whether treatment with a benzodiazepine GABAA α1-preferring ligand, 3-isopropoxy-β-carboline hydrochloride (3-ISOPBC), selectively decreases alcohol seeking and consumption. METHODS Eight baboons self-administered alcohol (4% w/v; n=5; alcohol group) or a non-alcoholic beverage (n=3; control group) in Component 3 of a chained schedule of reinforcement. Responses in Component 2 provided indices of motivation to drink (seeking). Doses of 3-ISOPBC (5.0-30.0mg/kg) and vehicle were administered before drinking sessions under both acute and chronic (5day) conditions. RESULTS Chronic, and not acute, administration of 3-ISOPBC significantly decreased self-administration responses, g/kg alcohol consumed, and the number of drinks in and duration of the first drinking bout in the alcohol group. In the control group, chronic administration of 3-ISOPBC did not significantly decrease any of these measures at any of the doses. CONCLUSIONS The GABAA α1-preferring ligand 3-ISOPBC may have therapeutic potential in the treatment of alcohol use disorder due to its ability to selectively reduce alcohol use.
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Affiliation(s)
- August F Holtyn
- Johns Hopkins University School of Medicine, Division of Behavioral Biology, 5510 Nathan Shock Dr, Baltimore, MD 21224, USA
| | - V V N Phani Babu Tiruveedhula
- University of Wisconsin-Milwaukee, Department of Chemistry & Biochemistry, 3210 N Cramer St, Milwaukee, WI 53201, USA
| | - Michael Rajesh Stephen
- University of Wisconsin-Milwaukee, Department of Chemistry & Biochemistry, 3210 N Cramer St, Milwaukee, WI 53201, USA
| | - James M Cook
- University of Wisconsin-Milwaukee, Department of Chemistry & Biochemistry, 3210 N Cramer St, Milwaukee, WI 53201, USA
| | - Elise M Weerts
- Johns Hopkins University School of Medicine, Division of Behavioral Biology, 5510 Nathan Shock Dr, Baltimore, MD 21224, USA.
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McKim TH, Shnitko TA, Robinson DL, Boettiger CA. Translational Research on Habit and Alcohol. CURRENT ADDICTION REPORTS 2016; 3:37-49. [PMID: 26925365 DOI: 10.1007/s40429-016-0089-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Habitual actions enable efficient daily living, but they can also contribute to pathological behaviors that resistant change, such as alcoholism. Habitual behaviors are learned actions that appear goal-directed but are in fact no longer under the control of the action's outcome. Instead, these actions are triggered by stimuli, which may be exogenous or interoceptive, discrete or contextual. A major hallmark characteristic of alcoholism is continued alcohol use despite serious negative consequences. In essence, although the outcome of alcohol seeking and drinking is dramatically devalued, these actions persist, often triggered by environmental cues associated with alcohol use. Thus, alcoholism meets the definition of an initially goal-directed behavior that converts to a habit-based process. Habit and alcohol have been well investigated in rodent models, with comparatively less research in non-human primates and people. This review focuses on translational research on habit and alcohol with an emphasis on cross-species methodology and neural circuitry.
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Affiliation(s)
- Theresa H McKim
- University of North Carolina at Chapel Hill, Department of Psychology and Neuroscience, Davie Hall, CB #3270, Chapel Hill, NC 27599
| | - Tatiana A Shnitko
- University of North Carolina at Chapel Hill, Bowles Center for Alcohol Studies, CB #7178, Chapel Hill, NC 27599
| | - Donita L Robinson
- University of North Carolina at Chapel Hill, Department of Psychiatry, Bowles Center for Alcohol Studies, CB #7178, Chapel Hill, NC 27599
| | - Charlotte A Boettiger
- Biomedical Research Imaging Center, Bowles Center for Alcohol Studies, Davie Hall, CB #3270, Chapel Hill, NC 27599
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Giuliano C, Goodlett CR, Economidou D, García-Pardo MP, Belin D, Robbins TW, Bullmore ET, Everitt BJ. The Novel μ-Opioid Receptor Antagonist GSK1521498 Decreases Both Alcohol Seeking and Drinking: Evidence from a New Preclinical Model of Alcohol Seeking. Neuropsychopharmacology 2015; 40:2981-92. [PMID: 26044906 PMCID: PMC4864633 DOI: 10.1038/npp.2015.152] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2015] [Revised: 05/07/2015] [Accepted: 05/08/2015] [Indexed: 02/02/2023]
Abstract
Distinct environmental and conditioned stimuli influencing ethanol-associated appetitive and consummatory behaviors may jointly contribute to alcohol addiction. To develop an effective translational animal model that illuminates this interaction, daily seeking responses, maintained by alcohol-associated conditioned stimuli (CSs), need to be dissociated from alcohol drinking behavior. For this, we established a procedure whereby alcohol seeking maintained by alcohol-associated CSs is followed by a period during which rats have the opportunity to drink alcohol. This cue-controlled alcohol-seeking procedure was used to compare the effects of naltrexone and GSK1521498, a novel selective μ-opioid receptor antagonist, on both voluntary alcohol-intake and alcohol-seeking behaviors. Rederived alcohol-preferring, alcohol-nonpreferring, and high-alcohol-drinking replicate 1 line of rats (Indiana University) first received 18 sessions of 24 h home cage access to 10% alcohol and water under a 2-bottle choice procedure. They were trained subsequently to respond instrumentally for access to 15% alcohol under a second-order schedule of reinforcement, in which a prolonged period of alcohol-seeking behavior was maintained by contingent presentations of an alcohol-associated CS acting as a conditioned reinforcer. This seeking period was terminated by 20 min of free alcohol drinking access that achieved significant blood alcohol concentrations. The influence of pretreatment with either naltrexone (0.1-1-3 mg/kg) or GSK1521498 (0.1-1-3 mg/kg) before instrumental sessions was measured on both seeking and drinking behaviors, as well as on drinking in the 2-bottle choice procedure. Naltrexone and GSK1521498 dose-dependently reduced both cue-controlled alcohol seeking and alcohol intake in the instrumental context as well as alcohol intake in the choice procedure. However, GSK1521498 showed significantly greater effectiveness than naltrexone, supporting its potential use for promoting abstinence and preventing relapse in alcohol addiction.
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Affiliation(s)
- Chiara Giuliano
- Behavioral and Clinical Neuroscience Institute and Department of Psychology, University of Cambridge, Cambridge, UK,Department of Psychology, University of Cambridge, Downing Street, Cambridge CB2 3EB, UK, Tel: +44 (0)1223 65292, Fax: +44 (0)1223 333564, E-mail:
| | - Charles R Goodlett
- Department of Psychology, Indiana University–Purdue University Indianapolis, Indianapolis, IN, USA
| | - Daina Economidou
- Behavioral and Clinical Neuroscience Institute and Department of Psychology, University of Cambridge, Cambridge, UK
| | - Maria P García-Pardo
- Unit of Research Psychobiology of Drug Dependence, Department of Psychobiology, School of Psychology, University of Valencia, Valencia, Spain
| | - David Belin
- Department of Pharmacology, University of Cambridge, Cambridge, UK
| | - Trevor W Robbins
- Behavioral and Clinical Neuroscience Institute and Department of Psychology, University of Cambridge, Cambridge, UK
| | - Edward T Bullmore
- Behavioral and Clinical Neuroscience Institute and Department of Psychology, University of Cambridge, Cambridge, UK,Department of Psychiatry, University of Cambridge, Cambridge, UK,Clinical Unit Cambridge and Academic DPU, GlaxoSmithKline R&D, Clinical Unit Cambridge, Addenbrooke's Hospital, Cambridge, UK
| | - Barry J Everitt
- Behavioral and Clinical Neuroscience Institute and Department of Psychology, University of Cambridge, Cambridge, UK
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Operant self-administration of ethanol in infant rats. Physiol Behav 2015; 148:87-99. [DOI: 10.1016/j.physbeh.2014.08.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Revised: 08/06/2014] [Accepted: 08/25/2014] [Indexed: 11/19/2022]
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12
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Ethanol self-administration in mice under a second-order schedule. Alcohol 2015; 49:561-70. [PMID: 26254963 DOI: 10.1016/j.alcohol.2015.06.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Revised: 06/09/2015] [Accepted: 06/20/2015] [Indexed: 11/23/2022]
Abstract
Long Fixed-Interval (FI) schedules, particularly second-order schedules, can engender substantial responding before drug or ethanol delivery that is uninfluenced by the direct effects of the drug or ethanol. Thus, these schedules can be used to study the effects of medications upon drug- or ethanol-seeking, uninfluenced by the direct effects of the self-administered drug or ethanol. Long FI second-order schedules are frequently used in primates and occasionally in rats. Under second-order schedules, completion of one response requirement, e.g., a Fixed Ratio 10 (FR10:S), produces a brief stimulus presentation, e.g., a 1-s 80-dB 4-kHZ tone, and this FR10:S serves as the response unit under another schedule, e.g., an FI 1800-s. Thus, the first FR10 completed after 1800 s would result in delivery both of the tone and of reinforcement, e.g., 10 × 0.01 mL 16% (w/v) ethanol. To examine if such schedules could be effectively used in mice, which have advantages in neurobiological and genetic studies, we trained eight C57BL/6J mice to respond under the schedule just described. This schedule maintained substantial responding. The temporal pattern of behavior was typical of an FI schedule with responding accelerating across the interval. We also examined the effects of acute and chronic administration of fluvoxamine on this responding, and these were modest. Finally, we examined responding when alcohol and/or tone deliveries were withheld, and found that extinction occurred most rapidly when both were withheld. This work demonstrates that long FI schedules of ethanol delivery may be useful in studying ethanol seeking in mice.
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Holtyn AF, Kaminski BJ, Wand GS, Weerts EM. Differences in extinction of cue-maintained conditioned responses associated with self-administration: alcohol versus a nonalcoholic reinforcer. Alcohol Clin Exp Res 2014; 38:2639-46. [PMID: 25336025 DOI: 10.1111/acer.12537] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Accepted: 07/30/2014] [Indexed: 11/27/2022]
Abstract
BACKGROUND Stimuli paired with alcohol may evoke conditioned responses that influence consumption and relapse. Understanding extinction of conditioned responses for both alcohol and nonalcoholic reinforcers, and their relation to subsequent consumption, may be useful in identifying methods to maintain abstinence. METHODS Nine baboons self-administered alcohol (n = 4) or a nonalcoholic reinforcer (orange-flavored Tang(®) , n = 5) under a 3-component chained schedule of reinforcement (CSR). Each component was associated with distinct stimuli and response requirements, which modeled periods of anticipation (Component 1), seeking (Component 2), and consumption (Component 3). No behavioral contingencies were in effect during Component 1. Responses in Component 2, required to gain access to Component 3, provided indices of seeking behavior. Alcohol or Tang® was available only in Component 3. Initial conditions parametrically manipulated the concentration of alcohol (2 to 6% w/v) or Tang (25 to 100%) that was available for self-administration. The breaking point (BP) of alcohol- and Tang-seeking responses at each of the concentrations was determined by adding a progressive ratio schedule to Component 2. Extinction of responding under stimulus conditions identical to those during baseline, but with no access to alcohol or Tang, was examined using across- and within-session extinction procedures. RESULTS The BP for 2% w/v alcohol was lower than that for 4 and 6%, which were closely similar. For Tang, BPs increased as the concentration increased. When concentrations of alcohol and Tang were adjusted to produce comparable BPs, self-administration of Tang was higher when compared to alcohol; however, alcohol-related cues maintained higher BPs than Tang-related cues when only water was available for self-administration. Alcohol seeking and self-administration responses were more resistant to extinction than those for Tang. CONCLUSIONS Stimuli paired with alcohol or nonalcoholic reinforcers will gain different motivational properties. Alcohol-related stimuli produced persistent responding that was highly resistant to change, highlighting the role of environmental stimuli in compulsive drinking and relapse.
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Affiliation(s)
- August F Holtyn
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland
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Kaminski BJ, Weerts EM. The effects of varenicline on alcohol seeking and self-administration in baboons. Alcohol Clin Exp Res 2014; 38:376-83. [PMID: 24033702 PMCID: PMC3868628 DOI: 10.1111/acer.12233] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Accepted: 06/16/2013] [Indexed: 11/27/2022]
Abstract
BACKGROUND Nicotinic acetylcholine receptors (nAChRs) may play a critical role in alcohol reinforcement and consumption. The effects of varenicline, an nAChR partial agonist, on alcohol seeking and self-administration responses were evaluated in 2 groups of baboons trained under a 3-component chained schedule of reinforcement (CSR). METHODS Alcohol (4% w/v; n = 4; alcohol group) or a preferred nonalcoholic beverage (n = 4; control group) was available for self-administration only in component 3 of the CSR. Responses in component 2, required to gain access to alcohol, provided indices of seeking behavior. Varenicline (0.032 to 0.32 mg/kg; 0.32 mg/kg twice daily [BID]) and vehicle were administered before CSR sessions subchronically (5 consecutive days). Higher doses (0.56, 1.0 mg/kg) were attempted, but discontinued due to adverse effects. RESULTS Subchronic varenicline administration significantly (p < 0.05) decreased the seeking response rate and increased the time to complete the response requirement to gain access to the daily supply of alcohol at the higher doses (0.32 mg/kg, 0.32 mg/kg BID dosing) in the alcohol group compared with the control group. Mean number of drinks was significantly decreased (p < 0.05), but effects did not differ between groups. The pattern of drinking was characterized by a high rate during an initial bout. Number of drinks during and duration of the initial bout were significantly decreased in the alcohol group, compared with the control group, at 0.32 mg/kg (p < 0.05). CONCLUSIONS Varenicline may be clinically useful for reducing alcohol-seeking behaviors prior to alcohol exposure. Given the modest effects on drinking itself, varenicline may be better suited as a treatment in combination with a pharmacotherapy that significantly reduces alcohol consumption.
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Affiliation(s)
- Barbara J. Kaminski
- Division of Behavioral Biology, Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, 5510 Nathan Shock Drive, Baltimore, MD, 21224
| | - Elise M. Weerts
- Division of Behavioral Biology, Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, 5510 Nathan Shock Drive, Baltimore, MD, 21224
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Duke AN, Kaminski BJ, Weerts EM. Baclofen effects on alcohol seeking, self-administration and extinction of seeking responses in a within-session design in baboons. Addict Biol 2014; 19:16-26. [PMID: 22458648 DOI: 10.1111/j.1369-1600.2012.00448.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Baclofen, a gamma-aminobutyric acidB receptor agonist, is currently under investigation as a potential treatment to prevent relapse to drinking in alcohol-dependent persons. In the current study, two groups of baboons were trained under a chained schedule of reinforcement (CSR), with three linked components, which were each correlated with different response requirements and cues. Fulfilling the requirement in the second link initiated the third link where either alcohol (n = 4) or a preferred non-alcoholic beverage (Tang, n = 5) was available for self-administration; failure to complete the response requirement in Link 2 ended the session (no access to alcohol or Tang). Seeking responses in Link 2 were used as indices of the motivational processes thought to be involved in relapse. The effects of baclofen (0.1-2.4 mg/kg) were examined under conditions with alcohol or Tang access and under extinction. Under the CSR, baclofen (1.8 and 2.4 mg/kg) significantly decreased (P < 0.05) alcohol self-administration responses and total g/kg alcohol intake. In contrast, only the highest dose of baclofen (2.4 mg/kg) reduced Tang self-administration and consumption. Under within-session extinction conditions, baclofen (1.8 and 2.4 mg/kg) facilitated extinction of responding for both alcohol and Tang, particularly during the first 10 minutes of extinction. Baclofen may be effective in reducing craving and alcohol drinking, although the facilitation of extinction and suppression of both alcohol and Tang self-administration by baclofen suggests these effects may be related to a more general suppression of consummatory and conditioned behaviors.
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Affiliation(s)
- Angela N Duke
- Department of Psychiatry and Behavioral Sciences, Division of Behavioral Biology, Johns Hopkins University School of Medicine, Suite, Baltimore, MD, USA
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Kaminski BJ, Van Linn ML, Cook JM, Yin W, Weerts EM. Effects of the benzodiazepine GABAA α1-preferring ligand, 3-propoxy-β-carboline hydrochloride (3-PBC), on alcohol seeking and self-administration in baboons. Psychopharmacology (Berl) 2013; 227:127-36. [PMID: 23271191 PMCID: PMC3624026 DOI: 10.1007/s00213-012-2946-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2012] [Accepted: 12/01/2012] [Indexed: 12/18/2022]
Abstract
RATIONALE The various α subtypes of GABAA receptors have been strongly implicated in alcohol reinforcement and consumption. OBJECTIVES The effects of the GABAA α1-preferring ligand, 3-propoxy-β-carboline hydrochloride (3-PBC), on seeking and self-administration responses were evaluated in two groups of baboons trained under a 3-component chained schedule of reinforcement (CSR). METHODS Alcohol (4 % w/v; n = 5; alcohol group) or a preferred nonalcoholic beverage (n = 4; control group) was available for self-administration only in component 3 of the CSR. Responses in component 2 provided indices of motivation to drink (seeking). 3-PBC (1.0-30.0 mg/kg) and saline were administered before drinking sessions under both acute and 5-day dosing conditions. RESULTS Repeated, and not acute, doses of 3-PBC significantly decreased total self-administration responses (p < 0.05), volume consumed (p < 0.05), and gram per kilogram of alcohol (p < 0.05) in the alcohol group. In the control group, 5-day administration of 3-PBC significantly decreased total self-administration responses (p < 0.05) but produced nonsignificant decreases in volume consumed. Within-session pattern of drinking was characterized by a high level of drinking in the first 20 min of the session for both groups, which was significantly (p < 0.05) decreased by all doses of 3-PBC (1.0-18.0 mg/kg) only in the alcohol group. In contrast, the first drinking bout in the control group was only reduced at the highest doses of 3-PBC (10.0 and 18.0 mg/kg). CONCLUSIONS The results support the involvement of the GABAA α1 subtype receptor in alcohol reinforcement and consumption.
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Affiliation(s)
- Barbara J. Kaminski
- Division of Behavioral Biology, Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, 5510 Nathan Shock Drive, Baltimore, MD, 21224
| | - Michael L. Van Linn
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, WI 53201
| | - James M. Cook
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, WI 53201
| | - Wenyuan Yin
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, WI 53201
| | - Elise M. Weerts
- Division of Behavioral Biology, Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, 5510 Nathan Shock Drive, Baltimore, MD, 21224
- Corresponding Author: Elise M. Weerts, Ph.D., Johns Hopkins Bayview Campus, Behavioral Biology Research Center, 5510 Nathan Shock Drive, Suite 3000, Baltimore, MD 21224, USA Tel.: 410-550-2781; Fax: 410-550-2780;
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Effects of naltrexone on alcohol drinking patterns and extinction of alcohol seeking in baboons. Psychopharmacology (Berl) 2012; 223:55-66. [PMID: 22451093 PMCID: PMC3419300 DOI: 10.1007/s00213-012-2688-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2011] [Accepted: 03/01/2012] [Indexed: 02/05/2023]
Abstract
RATIONALE Understanding naltrexone's effect on motivation to drink and pattern of drinking is important for better treatment outcomes and for comparison with novel medications. OBJECTIVES Naltrexone's effects on number and pattern of seeking, self-administration, and extinction responses were evaluated in two groups of baboons trained under a three-component chained schedule of reinforcement (CSR). METHODS Alcohol (4 % w/v; n = 4; alcohol group) or a preferred nonalcoholic beverage (n = 4; control group) was available for self-administration only in component 3 of the CSR. Responses in component 2 provided indices of motivation to drink (seeking). Naltrexone (0.32-3.2 mg/kg) and saline were administered before drinking and component 2 extinction sessions. RESULTS Acute doses of naltrexone significantly decreased total self-administration responses (p < 0.01), intake volume (p < 0.001), and grams per kilogram of alcohol (p < 0.01) in the alcohol group only. Pattern of drinking did not change, but the number of drinks during the initial drinking bout was decreased significantly by naltrexone for both groups (p < 0.05). During within-session extinction tests, acute naltrexone significantly decreased time to reach extinction (p < 0.01) and number of seeking responses (p < 0.05), particularly early in the extinction period in the alcohol group only. When administered chronically, naltrexone did not decrease progressive ratio breaking points to gain access to alcohol, but dose dependently reduced alcohol self-administration (p < 0.05) by decreasing the magnitude of the initial drinking bout. CONCLUSIONS The results support clinical observations that naltrexone may be most effective at reducing self-administration in the context of ongoing alcohol availability and may reduce motivation to drink in the presence of alcohol-related cues.
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Who is at risk? Population characterization of alcohol self-administration in nonhuman primates helps identify pathways to dependence. ALCOHOL RESEARCH & HEALTH : THE JOURNAL OF THE NATIONAL INSTITUTE ON ALCOHOL ABUSE AND ALCOHOLISM 2008; 31:289-97. [PMID: 23584006 PMCID: PMC3860464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Alcohol abuse and dependence are human conditions for which no full equivalent exists in animals. Nevertheless, animal models frequently are used to study various aspects of alcohol dependence that cannot be easily or ethically assessed in humans, including neurobiological mechanisms underlying alcohol dependence. Many of these animal models involve rodents; however, the characteristics (i.e., phenotypes) of chronic heavy drinking may be limited in these species. Nonhuman primates add an important translational aspect to the study of alcohol abuse and alcoholism. Their genetic, anatomical, physiological, and behavioral similarity to humans offers unique opportunities for identifying risk factors that may predispose a person to or accelerate the course of alcohol addiction. Studying alcohol consumption in nonhuman primates, including the distribution of drinking levels in a population, also can be uniquely informative to alcohol research. For example, research on the self-administration procedures in primates can help scientists identify risk factors for excessive alcohol consumption in humans. The phenotype of excessive drinking then can serve as the starting point to test and verify the underlying genetic and environmental influences. The resulting findings, in turn, can help guide prevention and treatment strategies.
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