1
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Heilig M. Stress-related neuropeptide systems as targets for treatment of alcohol addiction: A clinical perspective. J Intern Med 2023; 293:559-573. [PMID: 37052145 DOI: 10.1111/joim.13636] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 04/14/2023]
Abstract
Alcohol use is a major cause of disability and death globally. These negative consequences disproportionately affect people who develop alcohol addiction, a chronic relapsing condition characterized by increased motivation to use alcohol, choice of alcohol over healthy, natural rewards, and continued use despite negative consequences. Available pharmacotherapies for alcohol addiction are few, have effect sizes in need of improvement, and remain infrequently prescribed. Research aimed at developing novel therapeutics has in large part focused on attenuating pleasurable or "rewarding" properties of alcohol, but this targets processes that primarily play a role as initiation factors. As clinical alcohol addiction develops, long-term changes in brain function result in a shift of affective homeostasis, and rewarding alcohol effects become progressively reduced. Instead, increased stress sensitivity and negative affective states emerge in the absence of alcohol and create powerful incentives for relapse and continued use through negative reinforcement, or "relief." Based on research in animal models, several neuropeptide systems have been proposed to play an important role in this shift, suggesting that these systems could be targeted by novel medications. Two mechanisms in this category, antagonism at corticotropin-releasing factor type 1, and neurokinin 1/substance P receptors, have been subject to initial evaluation in humans. A third, kappa-opioid receptor antagonism, has been evaluated in nicotine addiction and could soon be tested for alcohol. This paper discusses findings with these mechanisms to date, and their prospects as future targets for novel medications.
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Affiliation(s)
- Markus Heilig
- Center for Social and Affective Neuroscience, BKV, Linköping University and Department of Psychiatry, Linköping University Hospital, Linköping, Sweden
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2
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Margolis EB, Moulton MG, Lambeth PS, O'Meara MJ. The life and times of endogenous opioid peptides: Updated understanding of synthesis, spatiotemporal dynamics, and the clinical impact in alcohol use disorder. Neuropharmacology 2023; 225:109376. [PMID: 36516892 PMCID: PMC10548835 DOI: 10.1016/j.neuropharm.2022.109376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 12/03/2022] [Accepted: 12/08/2022] [Indexed: 12/14/2022]
Abstract
The opioid G-protein coupled receptors (GPCRs) strongly modulate many of the central nervous system structures that contribute to neurological and psychiatric disorders including pain, major depressive disorder, and substance use disorders. To better treat these and related diseases, it is essential to understand the signaling of their endogenous ligands. In this review, we focus on what is known and unknown about the regulation of the over two dozen endogenous peptides with high affinity for one or more of the opioid receptors. We briefly describe which peptides are produced, with a particular focus on the recently proposed possible synthesis pathways for the endomorphins. Next, we describe examples of endogenous opioid peptide expression organization in several neural circuits and how they appear to be released from specific neural compartments that vary across brain regions. We discuss current knowledge regarding the strength of neural activity required to drive endogenous opioid peptide release, clues about how far peptides diffuse from release sites, and their extracellular lifetime after release. Finally, as a translational example, we discuss the mechanisms of action of naltrexone (NTX), which is used clinically to treat alcohol use disorder. NTX is a synthetic morphine analog that non-specifically antagonizes the action of most endogenous opioid peptides developed in the 1960s and FDA approved in the 1980s. We review recent studies clarifying the precise endogenous activity that NTX prevents. Together, the works described here highlight the challenges and opportunities the complex opioid system presents as a therapeutic target.
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Affiliation(s)
- Elyssa B Margolis
- UCSF Weill Institute for Neurosciences, Department of Neurology, University of California, San Francisco, CA, USA; Neuroscience Graduate Program, University of California, San Francisco, CA, USA.
| | - Madelyn G Moulton
- UCSF Weill Institute for Neurosciences, Department of Neurology, University of California, San Francisco, CA, USA
| | - Philip S Lambeth
- UCSF Weill Institute for Neurosciences, Department of Neurology, University of California, San Francisco, CA, USA
| | - Matthew J O'Meara
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI, 48109, USA
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3
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Ray LA, Du H, Green R, Roche DJO, Bujarski S. Do behavioral pharmacology findings predict clinical trial outcomes? A proof-of-concept in medication development for alcohol use disorder. Neuropsychopharmacology 2021; 46:519-527. [PMID: 33235284 PMCID: PMC8026961 DOI: 10.1038/s41386-020-00913-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2020] [Revised: 10/31/2020] [Accepted: 11/05/2020] [Indexed: 12/21/2022]
Abstract
Behavioral pharmacology paradigms have been used for early efficacy testing of novel compounds for alcohol use disorder (AUD). However, the degree to which early efficacy in the human laboratory predicts clinical efficacy remains unclear. To address this gap in the literature we employed a novel meta-analytic approach. We searched the literature for medications tested for AUD using both behavioral pharmacology (i.e., alcohol administration) and randomized clinical trials (RCTs). For behavioral pharmacology, we computed medication effects on alcohol-induced stimulation, sedation, and craving during the alcohol administration (k = 51 studies, 24 medications). For RCTs, we computed medication effects on any drinking and heavy drinking (k = 118 studies, 17 medications). We used medication as the unit of analysis and applied the Williamson-York bivariate weighted least squares estimation to preserve the errors in both the independent and dependent variables. Results, with correction for publication bias, revealed a significant and positive relationship between medication effects on alcohol-induced stimulation (β = 1.18 p < 0.05), sedation (β = 2.38, p < 0.05), and craving (β = 3.28, p < 0.001) in the laboratory, and drinking outcomes in RCTs, such that medications that reduced stimulation, sedation, and craving during the alcohol administration were associated with better clinical outcomes. A leave-one-out Monte Carlo analysis examined the predictive utility of these laboratory endpoints for each medication. The observed clinical effect size was within one standard deviation of the mean predicted effect size for all but three pharmacotherapies. This proof-of-concept study demonstrates that behavioral pharmacology endpoints of alcohol-induced stimulation, sedation, and craving track medication effects from the human laboratory to clinical trial outcomes. These results apply to alcohol administration phenotypes and may be especially useful to medications for which the mechanisms of action involve alterations in subjective responses to alcohol (e.g., antagonist medication). These methods and results can be applied to a host of clinical questions and can streamline the process of screening novel compounds for AUD. For instance, this approach can be used to quantify the predictive utility of cue-reactivity screening models and even preclinical models of medication development.
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Affiliation(s)
- Lara A. Ray
- grid.19006.3e0000 0000 9632 6718University of California, Department of Psychology, Los Angeles, CA USA ,grid.19006.3e0000 0000 9632 6718University of California, Department of Psychiatry and Biobehavioral Sciences, Los Angeles, CA USA
| | - Han Du
- grid.19006.3e0000 0000 9632 6718University of California, Department of Psychology, Los Angeles, CA USA
| | - ReJoyce Green
- grid.19006.3e0000 0000 9632 6718University of California, Department of Psychology, Los Angeles, CA USA
| | - Daniel J. O. Roche
- grid.19006.3e0000 0000 9632 6718University of California, Department of Psychology, Los Angeles, CA USA
| | - Spencer Bujarski
- grid.19006.3e0000 0000 9632 6718University of California, Department of Psychology, Los Angeles, CA USA
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4
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Crabbe JC, Ozburn AR, Hitzemann RJ, Spence SE, Hack WR, Schlumbohm JP, Metten P. Tetracycline derivatives reduce binge alcohol consumption in High Drinking in the Dark mice. Brain Behav Immun Health 2020; 4:100061. [PMID: 34589846 PMCID: PMC8474687 DOI: 10.1016/j.bbih.2020.100061] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Accepted: 03/13/2020] [Indexed: 01/28/2023] Open
Abstract
Alcohol use disorders (AUDs) are prevalent, and are characterized by binge-like drinking, defined by patterns of focused drinking where dosages ingested in 2-4 h reach intoxicating blood alcohol levels (BALs). Current medications are few and compliance with the relatively rare prescribed usage is low. Hence, novel and more effective medications are needed. We developed a mouse model of genetic risk for binge drinking (HDID: High Drinking in the Dark mice) by selectively breeding for high BALs after binge drinking. A transcriptional analysis of HDID brain tissue with RNA-Seq implicated neuroinflammatory mechanisms, and, more specifically extracellular matrix genes, including those encoding matrix metalloproteinases (MMPs). Prior experiments from other groups have shown that the tetracycline derivatives doxycycline, minocycline, and tigecycline, reduce binge drinking in inbred C57BL/6J mice. We tested these three compounds in female and male HDID mice and found that all three reduced DID and BAL. They had drug-specific effects on intake of water or saccharin in the DID assay. Thus, our results show that the effectiveness of synthetic tetracycline derivatives as potential therapeutic agents for AUDs is not limited to the single C57BL/6J genotype previously targeted, but extends to a mouse model of a population at high risk for AUDs.
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Affiliation(s)
- John C. Crabbe
- Portland Alcohol Research Center, Department of Behavioral Neuroscience, Oregon Health & Science University and Portland VA Health Care System (R&D 12), 3710 SW US Veterans Hospital Road, Portland, OR, 97239, USA
| | - Angela R. Ozburn
- Portland Alcohol Research Center, Department of Behavioral Neuroscience, Oregon Health & Science University and Portland VA Health Care System (R&D 12), 3710 SW US Veterans Hospital Road, Portland, OR, 97239, USA
| | - Robert J. Hitzemann
- Portland Alcohol Research Center, Department of Behavioral Neuroscience, Oregon Health & Science University and Portland VA Health Care System (R&D 12), 3710 SW US Veterans Hospital Road, Portland, OR, 97239, USA
| | - Stephanie E. Spence
- Portland Alcohol Research Center, Department of Behavioral Neuroscience, Oregon Health & Science University and Portland VA Health Care System (R&D 12), 3710 SW US Veterans Hospital Road, Portland, OR, 97239, USA
| | - Wyatt R. Hack
- Portland Alcohol Research Center, Department of Behavioral Neuroscience, Oregon Health & Science University and Portland VA Health Care System (R&D 12), 3710 SW US Veterans Hospital Road, Portland, OR, 97239, USA
| | - Jason P. Schlumbohm
- Portland Alcohol Research Center, Department of Behavioral Neuroscience, Oregon Health & Science University and Portland VA Health Care System (R&D 12), 3710 SW US Veterans Hospital Road, Portland, OR, 97239, USA
| | - Pamela Metten
- Portland Alcohol Research Center, Department of Behavioral Neuroscience, Oregon Health & Science University and Portland VA Health Care System (R&D 12), 3710 SW US Veterans Hospital Road, Portland, OR, 97239, USA
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5
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Litten RZ, Falk DE, Ryan ML, Fertig J, Leggio L. Five Priority Areas for Improving Medications Development for Alcohol Use Disorder and Promoting Their Routine Use in Clinical Practice. Alcohol Clin Exp Res 2019; 44:23-35. [PMID: 31803968 DOI: 10.1111/acer.14233] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Accepted: 11/02/2019] [Indexed: 12/31/2022]
Affiliation(s)
- Raye Z Litten
- National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland
| | - Daniel E Falk
- National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland
| | - Megan L Ryan
- National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland
| | - Joanne Fertig
- National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland
| | - Lorenzo Leggio
- Section on Clinical Psychoneuroendocrinology and Neuropsychopharmacology, National Institute on Alcohol Abuse and Alcoholism and National Institute on Drug Abuse, National Institutes of Health, Bethesda, Maryland.,Medication Development Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, Maryland.,Center for Alcohol and Addiction Studies, Brown University, Providence, Rhode Island
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6
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Hansson AC, Gründer G, Hirth N, Noori HR, Spanagel R, Sommer WH. Dopamine and opioid systems adaptation in alcoholism revisited: Convergent evidence from positron emission tomography and postmortem studies. Neurosci Biobehav Rev 2019; 106:141-164. [DOI: 10.1016/j.neubiorev.2018.09.010] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 09/08/2018] [Accepted: 09/14/2018] [Indexed: 12/20/2022]
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7
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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: 1.0] [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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8
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Huynh N, Arabian NM, Asatryan L, Davies DL. Murine Drinking Models in the Development of Pharmacotherapies for Alcoholism: Drinking in the Dark and Two-bottle Choice. J Vis Exp 2019. [PMID: 30663649 DOI: 10.3791/57027] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Alcohol Use Disorder (AUD) is a major problem with more than an estimated 76 million people worldwide meeting the diagnostic criteria. Current treatments are limited to three FDA-approved medications that are largely ineffective even when combined with psychosocial intervention, as is evident by the high relapse rate. As such, the search for more novel treatments represents an important public health goal. To this end, the following protocol utilizes two simple rodent drinking models to assess the preclinical efficacy of lead anti-alcohol compounds: two-bottle choice (TBC) and drinking in the dark (DID). The former allows mice to voluntary drink in moderation while the latter induces mice to voluntary consume a large amount of alcohol in a short period that mimics binge drinking. The simple and high throughput nature of both of these paradigms allow for rapid screening of pharmacological agents or for identifying strains of mice that exhibit certain voluntary drinking behavior.
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Affiliation(s)
- Nhat Huynh
- Titus Family Department of Clinical Pharmacy and Pharmaceutical Economics & Policy, School of Pharmacy, University of Southern California
| | - Natalie M Arabian
- Titus Family Department of Clinical Pharmacy and Pharmaceutical Economics & Policy, School of Pharmacy, University of Southern California
| | - Liana Asatryan
- Titus Family Department of Clinical Pharmacy and Pharmaceutical Economics & Policy, School of Pharmacy, University of Southern California
| | - Daryl L Davies
- Titus Family Department of Clinical Pharmacy and Pharmaceutical Economics & Policy, School of Pharmacy, University of Southern California;
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9
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Ray LA, Bujarski S, Roche DJO, Magill M. Overcoming the "Valley of Death" in Medications Development for Alcohol Use Disorder. Alcohol Clin Exp Res 2018; 42:1612-1622. [PMID: 29969156 PMCID: PMC6146966 DOI: 10.1111/acer.13829] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Accepted: 06/27/2018] [Indexed: 12/29/2022]
Abstract
As the development of novel pharmacotherapies for alcohol use disorder (AUD) has been slow, the discovery and testing of more efficacious pharmacotherapies for AUD represent a high priority research area. In fact, the transition from preclinical to clinical testing of novel compounds has been termed the "valley of death" in medications development. One key obstacle consists of the lack of an articulated set of goals for each stage of medications development. Specifically, the knowledge outputs required to make the transition from safety testing, to early efficacy detection, to confirming clinical efficacy remain unclear, and this is despite a great deal of interest and substantial financial investment in developing novel therapeutics for AUD. This qualitative critical review seeks to draw parallels and lessons from the well-established stage model for behavioral therapies research with alcohol and other substance use disorders and to apply these insights into AUD pharmacotherapy development. We argue that human laboratory models and/or pilot randomized controlled trials should serve as intermediaries in the transition from preclinical studies to large, and costly, randomized controlled efficacy trials. The relative strengths and weaknesses of pilot clinical trials versus human laboratory studies for bridging the "valley of death" are discussed and explored via a Monte Carlo data simulation study. Multiple permutations of suitable research designs informed by the behavioral therapies development model are discussed with the overall goal of promoting consilience and maximizing efficiency across all phases of clinical testing of novel AUD pharmacotherapies.
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Affiliation(s)
- Lara A. Ray
- Department of Psychology, University of California, Los
Angeles, Los Angeles, CA, USA
| | - Spencer Bujarski
- Department of Psychology, University of California, Los
Angeles, Los Angeles, CA, USA
| | | | - Molly Magill
- Center for Alcohol and Addiction Studies, Brown University,
Providence, RI, USA
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10
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Abstract
Animal models provide rapid, inexpensive assessments of an investigational drug's therapeutic potential. Ideally, they support the plausibility of therapeutic efficacy and provide a rationale for further investigation. Here, I discuss how the absence of clear effective-ineffective categories for alcohol use disorder (AUD) medications and biases in the clinical and preclinical literature affect the development of predictive preclinical alcohol dependence (AD) models. Invoking the analogical argument concept from the philosophy of science field, I discuss how models of excessive alcohol drinking support the plausibility of clinical pharmacotherapy effects. Even though these models are not likely be completely discriminative, they are sensitive to clinically effective medications and have revealed dozens of novel medication targets. In that context, I discuss recent preclinical work on GLP-1 receptor agonists, phosphodiesterase inhibitors, glucocorticoid receptor antagonists, nociception agonists and antagonists, and CRF1 antagonists. Clinically approved medications are available for each of these drug classes. I conclude by advocating a translational approach in which drugs are evaluated highly congruent preclinical models and human laboratory studies. Once translation is established, I suggest the burden is to develop hypothesis-based therapeutic interventions maximizing the impact of the confirmed pharmacotherapeutic effects in the context of additional variables falling outside the model.
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Affiliation(s)
- Mark Egli
- Division of Neuroscience and Behavior, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, USA.
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11
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Pomrenze MB, Fetterly TL, Winder DG, Messing RO. The Corticotropin Releasing Factor Receptor 1 in Alcohol Use Disorder: Still a Valid Drug Target? Alcohol Clin Exp Res 2017; 41:1986-1999. [PMID: 28940382 PMCID: PMC5711524 DOI: 10.1111/acer.13507] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Accepted: 09/15/2017] [Indexed: 01/20/2023]
Abstract
Corticotropin releasing factor (CRF) is a neuropeptide that plays a key role in behavioral and physiological responses to stress. A large body of animal literature implicates CRF acting at type 1 CRF receptors (CRFR1) in consumption by alcohol-dependent subjects, stress-induced reinstatement of alcohol seeking, and possibly binge alcohol consumption. These studies have encouraged recent pilot studies of CRFR1 antagonists in humans with alcohol use disorder (AUD). It was a great disappointment to many in the field that these studies failed to show an effect of these compounds on stress-induced alcohol craving. Here, we examine these studies to explore potential limitations and discuss preclinical and human literature to ask whether CRFR1 is still a valid drug target to pursue for the treatment of AUD.
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Affiliation(s)
| | - Tracy L. Fetterly
- Department of Molecular Physiology & Biophysics, Vanderbilt
University, Nashville, TN
- Vanderbilt Neuroscience Graduate Program, Vanderbilt University,
Nashville, TN
| | - Danny G. Winder
- Department of Molecular Physiology & Biophysics, Vanderbilt
University, Nashville, TN
- Vanderbilt Center for Addiction Research, Vanderbilt University,
Nashville, TN
- Vanderbilt Neuroscience Graduate Program, Vanderbilt University,
Nashville, TN
| | - Robert O. Messing
- Institute for Neuroscience, University of Texas at Austin, Austin,
TX
- Departments of Neuroscience and Neurology, University of Texas at
Austin, Austin, TX
- Waggoner Center for Alcohol and Addiction Research, University of
Texas at Austin, Austin, TX
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12
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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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13
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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: 1.3] [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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14
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Crabbe JC, Ozburn AR, Metten P, Barkley-Levenson A, Schlumbohm JP, Spence SE, Hack WR, Huang LC. High Drinking in the Dark (HDID) mice are sensitive to the effects of some clinically relevant drugs to reduce binge-like drinking. Pharmacol Biochem Behav 2017; 160:55-62. [PMID: 28827047 PMCID: PMC5603423 DOI: 10.1016/j.pbb.2017.08.002] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Revised: 07/14/2017] [Accepted: 08/04/2017] [Indexed: 11/22/2022]
Abstract
BACKGROUND There is a serious public health need for better understanding of alcohol use disorder disease mechanisms and for improved treatments. At this writing, only three drugs are approved by the Food and Drug Administration as medications to treat alcohol use disorders - disulfiram, naltrexone, and acamprosate. Binge drinking is a form of abusive alcohol drinking defined by the NIAAA as a drinking to blood alcohol levels (BALs)>0.08% during a period of approximately 2h. To model genetic risk for binge-like drinking, we have used selective breeding to create a unique animal model, High Drinking in the Dark (HDID) mice. Behavioral characterization of HDID mice has revealed that HDID mice exhibit behavioral impairment after drinking, withdrawal after a single binge-drinking session, and escalate their intake in response to induction of successive cycles of dependence. Notably, HDID mice do not exhibit altered tastant preference or alcohol clearance rates. We therefore asked whether drugs of known clinical relevance could modulate binge-like ethanol drinking in HDID mice, reasoning that this characterization of HDID responses should inform future use of this genetic animal model for screening and development of novel potential therapeutics. METHODS We tested the efficacy of acamprosate and naltrexone to reduce binge-like drinking in HDID mice. Additionally, we tested the GABAB receptor agonist, baclofen, based on recent pre-clinical and clinical studies demonstrating that it reduces alcohol drinking. We elected not to include disulfiram due to its more limited clinical usage. Mice were tested after acute doses of drugs in the limited-access Drinking in the Dark (DID) paradigm. RESULTS HDID mice were sensitive to the effects of acamprosate and baclofen, but not naltrexone. Both drugs reduced binge-like drinking. However, naltrexone failed to reduce drinking in HDID mice. Thus, HDID mice may represent a useful model for screening novel compounds.
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Affiliation(s)
- John C Crabbe
- Portland Alcohol Research Center, Department of Behavioral Neuroscience, Oregon Health & Science University, and VA Portland Health Care System, Portland, OR 97239, USA.
| | - Angela R Ozburn
- Portland Alcohol Research Center, Department of Behavioral Neuroscience, Oregon Health & Science University, and VA Portland Health Care System, Portland, OR 97239, USA
| | - Pamela Metten
- Portland Alcohol Research Center, Department of Behavioral Neuroscience, Oregon Health & Science University, and VA Portland Health Care System, Portland, OR 97239, USA
| | - Amanda Barkley-Levenson
- Portland Alcohol Research Center, Department of Behavioral Neuroscience, Oregon Health & Science University, and VA Portland Health Care System, Portland, OR 97239, USA
| | - Jason P Schlumbohm
- Portland Alcohol Research Center, Department of Behavioral Neuroscience, Oregon Health & Science University, and VA Portland Health Care System, Portland, OR 97239, USA
| | - Stephanie E Spence
- Portland Alcohol Research Center, Department of Behavioral Neuroscience, Oregon Health & Science University, and VA Portland Health Care System, Portland, OR 97239, USA
| | - Wyatt R Hack
- Portland Alcohol Research Center, Department of Behavioral Neuroscience, Oregon Health & Science University, and VA Portland Health Care System, Portland, OR 97239, USA
| | - Lawrence C Huang
- Portland Alcohol Research Center, Department of Behavioral Neuroscience, Oregon Health & Science University, and VA Portland Health Care System, Portland, OR 97239, USA
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15
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Cosa A, Moreno A, Pacheco-Torres J, Ciccocioppo R, Hyytiä P, Sommer WH, Moratal D, Canals S. Multi-modal MRI classifiers identify excessive alcohol consumption and treatment effects in the brain. Addict Biol 2017; 22:1459-1472. [PMID: 27273582 DOI: 10.1111/adb.12418] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Revised: 04/22/2016] [Accepted: 05/13/2016] [Indexed: 12/14/2022]
Abstract
Robust neuroimaging markers of neuropsychiatric disorders have proven difficult to obtain. In alcohol use disorders, profound brain structural deficits can be found in severe alcoholic patients, but the heterogeneity of unimodal MRI measurements has so far precluded the identification of selective biomarkers, especially for early diagnosis. In the present work we used a combination of multiple MRI modalities to provide comprehensive and insightful descriptions of brain tissue microstructure. We performed a longitudinal experiment using Marchigian-Sardinian (msP) rats, an established model of chronic excessive alcohol consumption, and acquired multi-modal images before and after 1 month of alcohol consumption (6.8 ± 1.4 g/kg/day, mean ± SD), as well as after 1 week of abstinence with or without concomitant treatment with the antirelapse opioid antagonist naltrexone (2.5 mg/kg/day). We found remarkable sensitivity and selectivity to accurately classify brains affected by alcohol even after the relative short exposure period. One month drinking was enough to imprint a highly specific signature of alcohol consumption. Brain alterations were regionally specific and affected both gray and white matter and persisted into the early abstinence state without any detectable recovery. Interestingly, naltrexone treatment during early abstinence resulted in subtle brain changes that could be distinguished from non-treated abstinent brains, suggesting the existence of an intermediate state associated with brain recovery from alcohol exposure induced by medication. The presented framework is a promising tool for the development of biomarkers for clinical diagnosis of alcohol use disorders, with capacity to further inform about its progression and response to treatment.
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Affiliation(s)
- Alejandro Cosa
- Instituto de Neurociencias; Consejo Superior de Investigaciones Científicas and Universidad Miguel Hernández; Sant Joan d'Alacant Spain
- Center for Biomaterials and Tissue Engineering; Universitat Politècnica de València; Valencia Spain
| | - Andrea Moreno
- Instituto de Neurociencias; Consejo Superior de Investigaciones Científicas and Universidad Miguel Hernández; Sant Joan d'Alacant Spain
| | - Jesús Pacheco-Torres
- Instituto de Neurociencias; Consejo Superior de Investigaciones Científicas and Universidad Miguel Hernández; Sant Joan d'Alacant Spain
| | | | - Petri Hyytiä
- Department of Pharmacology, Faculty of Medicine; University of Helsinki; Helsinki Finland
| | - Wolfgang H. Sommer
- Department of Psychopharmacology, Central Institute of Mental Health; University of Heidelberg; Mannheim Germany
| | - David Moratal
- Center for Biomaterials and Tissue Engineering; Universitat Politècnica de València; Valencia Spain
| | - Santiago Canals
- Instituto de Neurociencias; Consejo Superior de Investigaciones Científicas and Universidad Miguel Hernández; Sant Joan d'Alacant Spain
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16
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The glucagon-like peptide 1 receptor agonist Exendin-4 decreases relapse-like drinking in socially housed mice. Pharmacol Biochem Behav 2017; 160:14-20. [PMID: 28778739 DOI: 10.1016/j.pbb.2017.07.014] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Revised: 06/26/2017] [Accepted: 07/31/2017] [Indexed: 12/21/2022]
Abstract
Glucagon-like peptide-1 (GLP-1) is a gut peptide that regulates food intake and glucose metabolism. GLP-1 is also produced and released in the brain, and GLP-1 receptors are expressed in brain regions important for alcohol and drug reward, and for the development of addiction. GLP-1 receptor agonists can decrease alcohol intake acutely in rodents. However, alcohol use disorder is a chronic condition that requires treatments to be effective in promoting abstinence from excessive alcohol consumption over time. Here, we assessed the effect of daily treatment with the GLP-1 receptor agonist Exendin-4 in an assay of relapse-like drinking in socially housed mice. Male C57BL/6NTac mice were allowed continuous access to alcohol without tastant in the home cage for 37days. Then, alcohol bottles were removed and Exendin-4 (1.5μg/kg/day) or saline was administered subcutaneously for 8days during alcohol deprivation. Treatment continued for 8 additional days after reintroducing access to alcohol. A high-precision automated fluid consumption system was used to monitor intake of alcohol and water, drinking kinetics, and locomotor activity. Exendin-4 prevented the deprivation-induced increase in alcohol intake observed in control mice, without significantly affecting total fluid intake, body weight, or locomotor activity. The reduced alcohol intake was caused by a protracted latency to the first drink of alcohol and a reduced number of drinking bouts, while bout size and duration were not affected. The effect was maintained undiminished throughout the treatment period. These findings support the possible use of GLP-1 receptor agonists in the treatment of alcohol use disorder.
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17
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Lidö HH, Jonsson S, Hyytiä P, Ericson M, Söderpalm B. Further characterization of the GlyT-1 inhibitor Org25935: anti-alcohol, neurobehavioral, and gene expression effects. J Neural Transm (Vienna) 2017; 124:607-619. [PMID: 28161754 PMCID: PMC5399095 DOI: 10.1007/s00702-017-1685-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Accepted: 01/22/2017] [Indexed: 12/25/2022]
Abstract
The glycine transporter-1 inhibitor Org25935 is a promising candidate in a treatment concept for alcohol use disorder targeting the glycine system. Org25935 inhibits ethanol-induced dopamine elevation in brain reward regions and reduces ethanol intake in Wistar rats. This study aimed to further characterise the compound and used ethanol consumption, behavioral measures, and gene expression as parameters to investigate the effects in Wistar rats and, as pharmacogenetic comparison, Alko-Alcohol (AA) rats. Animals were provided limited access to ethanol in a two-bottle free-choice paradigm with daily drug administration. Acute effects of Org25935 were estimated using locomotor activity and neurobehavioral status. Effects on gene expression in Wistar rats were measured with qPCR. The higher but not the lower dose of Org25935 reduced alcohol intake in Wistar rats. Unexpectedly, Org25935 reduced both ethanol and water intake and induced strong CNS-depressive effects in AA-rats (withdrawn from further studies). Neurobehavioral effects by Org25935 differed between the strains (AA-rats towards sedation). Org25935 did not affect gene expression at the mRNA level in the glycine system of Wistar rats. The data indicate a small therapeutic range for the anti-alcohol properties of Org25935, a finding that may guide further evaluations of the clinical utility of GlyT-1 inhibitors. The results point to the importance of pharmacogenetic considerations when developing drugs for alcohol-related medical concerns. Despite the lack of successful clinical outcomes, to date, the heterogeneity of drug action of Org25935 and similar agents and the unmet medical need justify further studies of glycinergic compounds in alcohol use disorder.
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Affiliation(s)
- Helga Höifödt Lidö
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden. .,Beroendekliniken, Sahlgrenska University Hospital, Gothenburg, Sweden.
| | - Susanne Jonsson
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Petri Hyytiä
- Department of Pharmacology, University of Helsinki, Helsinki, Finland
| | - Mia Ericson
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Bo Söderpalm
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.,Beroendekliniken, Sahlgrenska University Hospital, Gothenburg, Sweden
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18
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Litten RZ, Falk DE, Ryan ML, Fertig JB. Discovery, Development, and Adoption of Medications to Treat Alcohol Use Disorder: Goals for the Phases of Medications Development. Alcohol Clin Exp Res 2016; 40:1368-79. [PMID: 27184259 PMCID: PMC4930402 DOI: 10.1111/acer.13093] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Accepted: 04/04/2016] [Indexed: 01/05/2023]
Abstract
For more than 25 years, advances have been made in developing medications to treat alcohol use disorder (AUD), highlighted by the U.S. Food and Drug Administration's approval of naltrexone (oral and long-acting) and acamprosate. Despite this progress, more work remains to be done in this area because these medications, although effective for some people, do not work for everyone. A high priority for the National Institute on Alcohol Abuse and Alcohol is to put into place a solid infrastructure to aid in the development of medications that are more effective than those currently available and with few side effects. Medication development, especially for a disorder as complex as AUD, is challenging and involves multiple phases, including discovery of "druggable" targets, preclinical studies, human clinical trials, and the adoption and implementation of the new medication into mainstream medicine. A successful medications development program requires clearly established goals for each phase to ensure that a candidate compound is not trapped in one particular phase, a condition known as "the valley of death." In this article, the phases of medication development are described as they apply to AUD, and specific goals of each phase are identified for the next decade. In addition, several important crosscutting themes are outlined for each phase, all of which are essential for advancing medications development. These include identifying and validating screening models and druggable targets, making use of precision medicine, and establishing partnerships among key stakeholders. Our goal in writing this article is to provide a guide on medications development that will aid the alcohol research community in planning, testing, and developing medications for AUD.
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Affiliation(s)
- Raye Z Litten
- NIAAA's Clinical Investigations Group (NCIG), Division of Medications Development, National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland
| | - Daniel E Falk
- NIAAA's Clinical Investigations Group (NCIG), Division of Medications Development, National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland
| | - Megan L Ryan
- NIAAA's Clinical Investigations Group (NCIG), Division of Medications Development, National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland
| | - Joanne B Fertig
- NIAAA's Clinical Investigations Group (NCIG), Division of Medications Development, National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland
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19
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Kasten CR, Boehm SL. Preclinical Medication Development: New Targets and New Drugs. Alcohol Clin Exp Res 2016; 40:1418-24. [PMID: 27177689 PMCID: PMC4930385 DOI: 10.1111/acer.13105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Accepted: 04/17/2016] [Indexed: 11/26/2022]
Affiliation(s)
- Chelsea R. Kasten
- Department of Psychology and Indiana Alcohol Research Center, Indiana University – Purdue University of Indianapolis, Indianapolis, IN 46202
| | - Stephen L. Boehm
- Department of Psychology and Indiana Alcohol Research Center, Indiana University – Purdue University of Indianapolis, Indianapolis, IN 46202
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20
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Helms CM, Bell RL, Bennett AJ, Davies DL, Chester JA, Kosten TA, Leeman RF, Panicker S, Platt DM, Weiner JL, Edwards S. The importance of animals in advancing research on alcohol use disorders. Alcohol Clin Exp Res 2016; 39:575-8. [PMID: 25833015 DOI: 10.1111/acer.12668] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Revised: 12/18/2014] [Accepted: 12/30/2014] [Indexed: 01/01/2023]
Affiliation(s)
- Christa M Helms
- Division of Neuroscience, Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, Oregon
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21
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Egli M, White DA, Acri JB. Considerations in the Evaluation of Potential Efficacy of Medications for Alcohol and Drug Use Disorders: An Editorial. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2016; 126:1-14. [PMID: 27055609 DOI: 10.1016/bs.irn.2016.02.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
Abstract
The societal burden created by alcohol and drug use disorders is estimated to be on the order of hundreds of billions of dollars, creating a need for effective medications to reduce use and prevent relapse. While there are FDA-approved medications to facilitate abstinence and prevent relapse for some indications including, alcohol, tobacco, and opiate use disorders, there are no approved treatments for other abused substances, including cocaine, methamphetamine, and cannabis, leaving these critical medical needs unmet. The development of such medications has fallen largely to the government with efforts spearheaded by the National Institute on Drug Abuse and the National Institute on Alcoholism and Alcohol Abuse. Both agencies have medication development programs with preclinical components that include the standardized evaluation of compounds using animal models. This chapter describes the rationale and considerations involved in the use of such models, including reinstatement of drug self-administration.
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Affiliation(s)
- M Egli
- National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, United States
| | - D A White
- National Institute on Drug Abuse, National Institutes of Health, Bethesda, MD, United States.
| | - J B Acri
- National Institute on Drug Abuse, National Institutes of Health, Bethesda, MD, United States
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22
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Heilig M, Sommer WH, Spanagel R. The Need for Treatment Responsive Translational Biomarkers in Alcoholism Research. Curr Top Behav Neurosci 2016; 28:151-171. [PMID: 27240677 DOI: 10.1007/7854_2015_5006] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Over the past two decades, major advances have been made in the basic neuroscience of alcohol addiction. However, few of these have been translated into clinically useful treatments, which remain limited. In the past decade, psychiatric drug development in general has been stalled, with many preclinically validated mechanisms failing in clinical development. Despite the existence of appealing preclinical models in the area of addictive disorders, drug development for these conditions has been impacted by the exodus of major pharma from psychiatric neuroscience. Here, we discuss translational biomarker strategies that may help turn this tide. Following an approach patterned on an endophenotype approach to complex behavioral traits, we hypothesize that relatively simple biological measures should be sought that can be obtained both in experimental animals and in humans, and that may be responsive to alcoholism medications. These biomarkers have to be tailored to the specific mechanism targeted by candidate medications and may in fact also help identify biologically more homogeneous subpopulations of patients. We introduce as examples alcohol-induced dopamine (DA) release, measures of central glutamate levels, and network connectivity, and discuss our experience to date with these biomarker strategies.
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Affiliation(s)
- Markus Heilig
- Center for Social and Affective Neuroscience, Department of Clinical and Experimental Medicine, Linköping University, SE-58183, Linköping, Sweden.
| | - Wolfgang H Sommer
- Institute of Psychopharmacology, Central Institute of Mental Health, Faculty of Medicine Mannheim, University of Heidelberg, Heidelberg, Germany
| | - Rainer Spanagel
- Institute of Psychopharmacology, Central Institute of Mental Health, Faculty of Medicine Mannheim, University of Heidelberg, Heidelberg, Germany
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23
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Phillips TJ, Reed C, Pastor R. Preclinical evidence implicating corticotropin-releasing factor signaling in ethanol consumption and neuroadaptation. GENES BRAIN AND BEHAVIOR 2015; 14:98-135. [PMID: 25565358 DOI: 10.1111/gbb.12189] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Revised: 11/22/2014] [Accepted: 11/25/2014] [Indexed: 12/15/2022]
Abstract
The results of many studies support the influence of the corticotropin-releasing factor (CRF) system on ethanol (EtOH) consumption and EtOH-induced neuroadaptations that are critical in the addiction process. This review summarizes the preclinical data in this area after first providing an overview of the components of the CRF system. This complex system involves hypothalamic and extra-hypothalamic mechanisms that play a role in the central and peripheral consequences of stressors, including EtOH and other drugs of abuse. In addition, several endogenous ligands and targets make up this system and show differences in their involvement in EtOH drinking and in the effects of chronic or repeated EtOH treatment. In general, genetic and pharmacological approaches paint a consistent picture of the importance of CRF signaling via type 1 CRF receptors (CRF(1)) in EtOH-induced neuroadaptations that result in higher levels of intake, encourage alcohol seeking during abstinence and alter EtOH sensitivity. Furthermore, genetic findings in rodents, non-human primates and humans have provided some evidence of associations of genetic polymorphisms in CRF-related genes with EtOH drinking, although additional data are needed. These results suggest that CRF(1) antagonists have potential as pharmacotherapeutics for alcohol use disorders. However, given the broad and important role of these receptors in adaptation to environmental and other challenges, full antagonist effects may be too profound and consideration should be given to treatments with modulatory effects.
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Affiliation(s)
- T J Phillips
- VA Portland Health Care System, Portland Alcohol Research Center, Methamphetamine Abuse Research Center, Oregon Health & Science University, Portland, OR, USA; Department of Behavioral Neuroscience, Portland Alcohol Research Center, Methamphetamine Abuse Research Center, Oregon Health & Science University, Portland, OR, USA
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24
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Lee KM, Coehlo M, McGregor HA, Waltermire RS, Szumlinski KK. Binge alcohol drinking elicits persistent negative affect in mice. Behav Brain Res 2015; 291:385-398. [PMID: 26048424 PMCID: PMC4513951 DOI: 10.1016/j.bbr.2015.05.055] [Citation(s) in RCA: 84] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Revised: 05/26/2015] [Accepted: 05/31/2015] [Indexed: 01/21/2023]
Abstract
Cessation from chronic alcohol abuse often produces a dysphoric state that can persist into protracted withdrawal. This dysphoric state is theorized to function as a negative reinforcer that maintains excessive alcohol consumption and/or precipitates relapse in those struggling to abstain from alcohol. However, we know relatively little regarding the impact of cessation from binge drinking on behavioral measures of negative affect and related neurobiology. Male C57BL/6J mice were given access to unsweetened 20% alcohol for 6 weeks under modified Drinking-in-the-dark procedures, followed by behavioral testing beginning either 1 or 21 days into withdrawal. Mice were administered a behavioral test battery consisting of: the elevated plus maze, light/dark box, novel object test, marble burying test, Porsolt forced swim test and sucrose preference test to assess anxiogenic and depressive signs. Egr1 immunostaining was used to quantify cellular activity within the central nucleus of the amygdala (CEA), basolateral amygdala (BLA), bed nucleus of the stria terminalis (BNST), and the nucleus accumbens (Acb) shell (AcbSh) and core (AcbC). Compared to water controls, alcohol-drinking mice exhibited higher indices of emotionality in the majority of behavioral assays. The hyper-emotionality exhibited by binge drinking mice was apparent at both withdrawal time-points and correlated with higher Egr1+ cell counts in the CEA and BNST, compared to controls. These data show that affective symptoms emerge very early after cessation of binge drinking and persist into protracted withdrawal. A history of binge drinking is capable of producing enduring neuroadaptations within brain circuits mediating emotional arousal.
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Affiliation(s)
- Kaziya M Lee
- Department of Psychological and Brain Sciences, Neuroscience Research Institute, University of California, Santa Barbara, CA, USA
| | - Michal Coehlo
- Department of Psychological and Brain Sciences, Neuroscience Research Institute, University of California, Santa Barbara, CA, USA
| | - Hadley A McGregor
- Department of Psychological and Brain Sciences, Neuroscience Research Institute, University of California, Santa Barbara, CA, USA
| | - Ryan S Waltermire
- Department of Psychological and Brain Sciences, Neuroscience Research Institute, University of California, Santa Barbara, CA, USA
| | - Karen K Szumlinski
- Department of Psychological and Brain Sciences, Neuroscience Research Institute, University of California, Santa Barbara, CA, USA.
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25
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de Bejczy A, Nations KR, Szegedi A, Schoemaker J, Ruwe F, Söderpalm B. Efficacy and safety of the glycine transporter-1 inhibitor org 25935 for the prevention of relapse in alcohol-dependent patients: a randomized, double-blind, placebo-controlled trial. Alcohol Clin Exp Res 2015; 38:2427-35. [PMID: 25257291 DOI: 10.1111/acer.12501] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Accepted: 05/16/2014] [Indexed: 01/21/2023]
Abstract
BACKGROUND Org 25935 is a glycine transporter inhibitor that increases extracellular glycine levels and attenuates alcohol-induced dopaminergic activity in the nucleus accumbens. In animal models, Org 25935 has dose-dependent effects on ethanol intake, preference, and relapse-like behavior without tolerance. The current study aimed to translate these animal findings to humans by examining whether Org 25935 prevents relapse in detoxified alcohol-dependent patients. METHODS This was a multicenter, randomized, double-blind, placebo-controlled clinical trial. Adult patients diagnosed with alcohol dependence were randomly assigned to receive Org 25935 12 mg twice a day or placebo for 84 days. The primary end point was percentage heavy drinking days (defined as ≥ 5 standard drinks per day for men and ≥ 4 for women). Secondary end points included other measures of relapse-related drinking behavior (e.g., drinks per day, time to relapse), as well as measures of global functioning, alcohol-related thoughts and cravings, and motivation. RESULTS A total of 140 subjects were included in the intent-to-treat analysis. The trial was stopped approximately midway after a futility analysis showing that the likelihood of detecting a signal at study term was <40%. There was no significant difference between Org 25935 and placebo on percentage heavy drinking days or any other measure of relapse-related drinking behavior. Org 25935 showed no safety issues and was fairly well tolerated, with fatigue, dizziness, and transient visual events as the most commonly occurring side effects. CONCLUSIONS Org 25935 demonstrated no benefit over placebo in preventing alcohol relapse. Study limitations and implications are discussed.
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Affiliation(s)
- Andrea de Bejczy
- Addiction Biology Unit, Institute of Neuroscience and Physiology, University of Gothenburg, Gothenburg, Sweden
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26
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Bell RL, Lopez MF, Cui C, Egli M, Johnson KW, Franklin KM, Becker HC. Ibudilast reduces alcohol drinking in multiple animal models of alcohol dependence. Addict Biol 2015; 20:38-42. [PMID: 24215262 PMCID: PMC4017009 DOI: 10.1111/adb.12106] [Citation(s) in RCA: 111] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Neuroinflammatory signaling pathways in the central nervous system are of current interest as potential pharmacotherapy targets for alcohol dependence. In this study, we examined the ability of ibudilast, a non-selective phosphodiesterase inhibitor, to reduce alcohol drinking and relapse in alcohol-preferring P rats, high-alcohol drinking HAD1 rats, and in mice made dependent on alcohol through cycles of alcohol vapor exposure. When administered twice daily, ibudilast reduced alcohol drinking in rats by approximately 50% and reduced drinking by alcohol-dependent mice at doses which had no effect in non-dependent mice. These findings support the viability of ibudilast as a possible treatment for alcohol dependence.
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Affiliation(s)
- Richard L. Bell
- Department of Psychiatry and Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Marcelo F. Lopez
- Department of Psychiatry and Behavioral Sciences, Charleston Alcohol Research Center, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Changhai Cui
- Division of Neuroscience and Behavior, National Institute on Alcohol Abuse and Alcoholism, NIH, DHHS, Bethesda, MD 20892, USA
| | - Mark Egli
- Division of Neuroscience and Behavior, National Institute on Alcohol Abuse and Alcoholism, NIH, DHHS, Bethesda, MD 20892, USA
| | | | - Kelle M. Franklin
- Department of Psychiatry and Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Howard C. Becker
- Department of Psychiatry and Behavioral Sciences, Charleston Alcohol Research Center, Medical University of South Carolina, Charleston, SC 29425, USA
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27
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Meinhardt MW, Sommer WH. Postdependent state in rats as a model for medication development in alcoholism. Addict Biol 2015; 20:1-21. [PMID: 25403107 DOI: 10.1111/adb.12187] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Rational development of novel therapeutic strategies for alcoholism requires understanding of its underlying neurobiology and pathophysiology. Obtaining this knowledge largely relies on animal studies. Thus, choosing the appropriate animal model is one of the most critical steps in pre-clinical medication development. Among the range of animal models that have been used to investigate excessive alcohol consumption in rodents, the postdependent model stands out. It was specifically developed to test the role of negative affect as a key driving force in a perpetuating addiction cycle for alcoholism. Here, we will describe our approach to make rats dependent via chronic intermittent exposure to alcohol, discuss the validity of this model, and compare it with other commonly used animal models of alcoholism. We will summarize evidence that postdependent rats fulfill several criteria of a 'Diagnostic and Statistical Manual of Mental Disorders IV/V-like' diagnostic system. Importantly, these animals show long-lasting excessive consumption of and increased motivation for alcohol, and evidence for loss of control over alcohol intake. Our conclusion that postdependent rats are an excellent model for medication development for alcoholism is underscored by a summary of more than two dozen pharmacological tests aimed at reversing these abnormal alcohol responses. We will end with open questions on the use of this model. In the tradition of the Sanchis-Segura and Spanagel review, we provide comic strips that illustrate the postdependent procedure and relevant phenotypes in this review.
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Affiliation(s)
| | - Wolfgang H. Sommer
- Institute of Psychopharmacology; University of Heidelberg; Germany
- Department of Addiction Medicine; Central Institute of Mental Health; Medical Faculty Mannheim; University of Heidelberg; Germany
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28
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Leonelli S, Ankeny RA, Nelson NC, Ramsden E. Making organisms model human behavior: situated models in North-American alcohol research, since 1950. SCIENCE IN CONTEXT 2014; 27:485-509. [PMID: 25233743 PMCID: PMC4274764 DOI: 10.1017/s0269889714000155] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
We examine the criteria used to validate the use of nonhuman organisms in North-American alcohol addiction research from the 1950s to the present day. We argue that this field, where the similarities between behaviors in humans and non-humans are particularly difficult to assess, has addressed questions of model validity by transforming the situatedness of non-human organisms into an experimental tool. We demonstrate that model validity does not hinge on the standardization of one type of organism in isolation, as often the case with genetic model organisms. Rather, organisms are viewed as necessarily situated: they cannot be understood as a model for human behavior in isolation from their environmental conditions. Hence the environment itself is standardized as part of the modeling process; and model validity is assessed with reference to the environmental conditions under which organisms are studied.
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Affiliation(s)
| | - Rachel A. Ankeny
- School of History & Politics, University of Adelaide, Napier 423, Adelaide 5005 SA, Australia,
| | - Nicole C. Nelson
- Department of Social Studies of Medicine, McGill University, 3647 Peel Room 207, Montreal QC, H3A 1X1, Canada,
| | - Edmund Ramsden
- Centre for the History of Science, Technology and Medicine, Faculty of Life Sciences, University of Manchester, Simon Building, Manchester, M13 9PL, UK
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29
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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: 2.6] [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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Abstract
Alcoholism (alcohol dependence and alcohol use disorder, AUD) is quintessentially behavioral in nature. AUD is behaviorally and genetically complex. This review discusses behavioral assessment of alcohol sensitivity, tolerance, dependence, withdrawal, and reinforcement. The focus is on using laboratory animal models to explore genetic contributions to individual differences in alcohol responses. Rodent genetic animal models based on selective breeding for high vs low alcohol response, and those based on the use of inbred strains, are reviewed. Genetic strategies have revealed the complexity of alcohol responses where genetic influences on multiple alcohol-related behaviors are mostly discrete. They have also identified areas where genetic influences are consistent across behavioral assays and have been used to model genetic differences among humans at different risk for AUD.
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Affiliation(s)
- John C Crabbe
- Portland Alcohol Research Center and Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR, USA.
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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: 1.5] [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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Perspectives on the neuroscience of alcohol from the National Institute on Alcohol Abuse and Alcoholism. HANDBOOK OF CLINICAL NEUROLOGY 2014; 125:15-29. [PMID: 25307566 DOI: 10.1016/b978-0-444-62619-6.00002-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Mounting evidence over the last 40 years clearly indicates that alcoholism (alcohol dependence) is a disorder of the brain. The National Institute on Alcohol Abuse and Alcoholism (NIAAA) has taken significant steps to advance research into the neuroscience of alcohol. The Division of Neuroscience and Behavior (DNB) was formed within NIAAA in 2002 to oversee, fund, and direct all research areas that examine the effects of alcohol on the brain, the genetic underpinnings of alcohol dependence, the neuroadaptations resulting from excessive alcohol consumption, advanced behavioral models of the various stages of the addiction cycle, and preclinical medications development. This research portfolio has produced important discoveries in the etiology, treatment, and prevention of alcohol abuse and dependence. Several of these salient discoveries are highlighted and future areas of neuroscience research on alcohol are presented.
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Crabbe JC. Rodent models of genetic contributions to motivation to abuse alcohol. NEBRASKA SYMPOSIUM ON MOTIVATION. NEBRASKA SYMPOSIUM ON MOTIVATION 2014; 61:5-29. [PMID: 25306777 PMCID: PMC4988659 DOI: 10.1007/978-1-4939-0653-6_2] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
In summary, there are remarkably few studies focused on the genetic contributions to alcohol's reinforcing values. Almost all such studies examine the two-bottle preference test. Despite the deficiencies I have raised in its interpretation, a rodent genotype's willingness to drink ethanol when water is freely available offers a reasonable aggregate estimate of alcohol's reinforcing value relative to other genotypes (Green and Grahame 2008). As indicated above, however, preference drinking studies will likely never avoid the confounding role of taste preferences and most often yield intake levels not sufficient to yield a pharmacologically significant BAL. Thus, the quest for improved measures of reinforcing value continues. Of the potential motivational factors considered by McClearn in his seminal review in this series, we can safely conclude that rodent alcohol drinking is not primarily directed at obtaining calories. The role of taste (and odor) remains a challenge. McClearn appears to have been correct that especially those genotypes that avoid alcohol are probably doing so based on preingestive sensory cues; however, postingestive consequences are also important. Cunningham's intragastric model shows the role of both preingestional and postingestional modulating factors for the best known examples, the usually nearly absolutely alcohol-avoiding DBA/2J and HAP-2 mice. Much subsequent data reinforce McClearn's earlier conclusion that C57BL/6J mice, at least, do not regulate their intake around a given self-administered dose of alcohol by adjusting their intake. This leaves us with the puzzle of why nearly all genotypes, even those directionally selectively bred for high voluntary intake for many generations, fail to self-administer intoxicating amounts of alcohol. Since McClearn's review, many ingenious assays to index alcohol's motivational effects have been used extensively, and new methods for inducing dependence have supplanted the older ones prevalent in 1968. I have tried to identify promising areas where the power of genetics could be fruitfully harvested and generally feel that we have a much more clear idea now about some important experiments remaining to be performed.
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Affiliation(s)
- John C. Crabbe
- Portland Alcohol Research Center, Department of Behavioral Neuroscience, Oregon Health & Science University, and VA Medical Center (R&D 12), 3710 SW US Veterans Hospital Road, Portland, Oregon 97239 USA, Phone: 503-273-5298, FAX: 503-721-1029
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Tomie A, Azogu I, Yu L. Effects of naltrexone on post-abstinence alcohol drinking in C57BL/6NCRL and DBA/2J mice. Prog Neuropsychopharmacol Biol Psychiatry 2013; 44:240-7. [PMID: 23499782 PMCID: PMC3713418 DOI: 10.1016/j.pnpbp.2013.03.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Revised: 02/20/2013] [Accepted: 03/01/2013] [Indexed: 11/18/2022]
Abstract
The present experiment evaluated the effects of naltrexone, a non-selective opioid receptor antagonist, on post-abstinence alcohol drinking in C57BL/6NCRL and DBA/2J male mice. Home cage 2-bottle (alcohol vs. water) free-choice procedures were employed. During the pre-abstinence period, alcohol intake was much lower for the DBA/2J mice relative to the C57BL/6NCRL mice, and this strain difference was observed for groups receiving either 3% or 10% alcohol concentrations. The four-day abstinence period effectively reduced alcohol intakes (i.e., a negative alcohol deprivation effect, negative ADE) in both groups of DBA/2J mice, but had no effect on alcohol intakes in either group of C57BL/6NCRL mice. Both groups trained with 3% alcohol received the second four-day abstinence period, where the effects of acute administration of either naltrexone or saline on post-abstinence alcohol drinking were assessed. Naltrexone was more effective in reducing post-abstinence drinking of 3% alcohol in the DBA/2J mice than in the C57BL/6NCRL mice. In the DBA/2J mice, naltrexone further reduced, relative to saline-injected controls, the low levels of post-abstinence alcohol intake. Thus, the low baseline levels of alcohol drinking in DBA/2J mice were further diminished by the four-day abstinence period (negative ADE), and this suppressed post-abstinence level of alcohol drinking was still further reduced by acute administration of naltrexone. The results indicate that naltrexone is effective in reducing further the low levels of alcohol drinking induced by the negative ADE.
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Affiliation(s)
- Arthur Tomie
- Department of Psychology and Center of Alcohol Studies, Rutgers University, 607 Allison Road, Piscataway, NJ 08854-8001, USA.
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35
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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: 1.0] [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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36
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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: 1.2] [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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Litten RZ, Egli M, Heilig M, Cui C, Fertig JB, Ryan ML, Falk DE, Moss H, Huebner R, Noronha A. Medications development to treat alcohol dependence: a vision for the next decade. Addict Biol 2012; 17:513-27. [PMID: 22458728 PMCID: PMC3484365 DOI: 10.1111/j.1369-1600.2012.00454.x] [Citation(s) in RCA: 166] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
More than 76 million people world-wide are estimated to have diagnosable alcohol use disorders (AUDs) (alcohol abuse or dependence), making these disorders a major global health problem. Pharmacotherapy offers promising means for treating AUDs, and significant progress has been made in the past 20 years. The US Food and Drug Administration approved three of the four medications for alcoholism in the last two decades. Unfortunately, these medications do not work for everyone, prompting the need for a personalized approach to optimize clinical benefit or more efficacious medications that can treat a wider range of patients, or both. To promote global health, the potential reorganization of the National Institutes of Health (NIH) must continue to support the National Institute on Alcohol Abuse and Alcoholism's (NIAAA's) vision of ensuring the development and delivery of new and more efficacious medications to treat AUDs in the coming decade. To achieve this objective, the NIAAA Medications Development Team has identified three fundamental long-range goals: (1) to make the drug development process more efficient; (2) to identify more efficacious medications, personalize treatment approaches, or both; and (3) to facilitate the implementation and adaptation of medications in real-world treatment settings. These goals will be carried out through seven key objectives. This paper describes those objectives in terms of rationale and strategy. Successful implementation of these objectives will result in the development of more efficacious and safe medications, provide a greater selection of therapy options and ultimately lessen the impact of this devastating disorder.
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Affiliation(s)
- Raye Z Litten
- National Institute on Alcohol Abuse and Alcoholism, Bethesda, MD, USA.
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38
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Heilig M, Goldman D, Berrettini W, O'Brien CP. Pharmacogenetic approaches to the treatment of alcohol addiction. Nat Rev Neurosci 2011; 12:670-84. [PMID: 22011682 PMCID: PMC3408029 DOI: 10.1038/nrn3110] [Citation(s) in RCA: 171] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Addictive disorders are partly heritable, chronic, relapsing conditions that account for a tremendous disease burden. Currently available addiction pharmacotherapies are only moderately successful, continue to be viewed with considerable scepticism outside the scientific community and have not become widely adopted as treatments. More effective medical treatments are needed to transform addiction treatment and address currently unmet medical needs. Emerging evidence from alcoholism research suggests that no single advance can be expected to fundamentally change treatment outcomes. Rather, studies of opioid, corticotropin-releasing factor, GABA and serotonin systems suggest that incremental advances in treatment outcomes will result from an improved understanding of the genetic heterogeneity among patients with alcohol addiction, and the development of personalized treatments.
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Affiliation(s)
- Markus Heilig
- Laboratory of Clinical and Translational Studies, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland 20892, USA. markus.heilig@mail. nih.gov
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Cippitelli A, Damadzic R, Singley E, Thorsell A, Ciccocioppo R, Eskay RL, Heilig M. Pharmacological blockade of corticotropin-releasing hormone receptor 1 (CRH1R) reduces voluntary consumption of high alcohol concentrations in non-dependent Wistar rats. Pharmacol Biochem Behav 2011; 100:522-9. [PMID: 22036774 DOI: 10.1016/j.pbb.2011.10.016] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2011] [Revised: 09/15/2011] [Accepted: 10/14/2011] [Indexed: 11/15/2022]
Abstract
BACKGROUND A dysregulation of the corticotropin-releasing hormone (CRH) system has been implicated in the development of excessive alcohol consumption and dependence. The aim of the present study was to evaluate whether the CRH system is also recruited when non-dependent Wistar rats escalate to high alcohol intake in the intermittent (alternate days) model of drinking. METHODS We compared intermittent and continuous access to 20% (v/v) alcohol in a two-bottle free choice drinking paradigm. Following a total of twenty 24-hour exposures for every experimental group, we assessed signs of alcohol withdrawal, including anxiety-like behavior and sensitivity to stress. The selective CRH1 receptor (CRH1R) antagonist antalarmin (0, 10, 20 mg/kg, i.p.) was tested on alcohol consumption. RESULTS Intermittent access to 20% alcohol led non-selected Wistar rats to escalate their voluntary intake to a high and stable level, whereas continuously exposed animals maintained a lower consumption. These groups did not differ in physical withdrawal signs. In addition, no differences were found when anxiogenic-like behavior was studied, neither under basal conditions or following restraint stress. Nevertheless, sensitivity to the treatment with the CRH1R antalarmin was observed since a reduction of 20% alcohol intake was found in both groups of animals regardless of the regimen of alcohol exposure. In addition, antalarmin was effective when injected to animals exposed to intermittent 10% (v/v) alcohol whereas it failed to suppress 10% continuous alcohol intake. CONCLUSIONS Pharmacological blockade of CRH1R reduced alcohol drinking when sustained high levels of intake were achieved suggesting that the CRH system plays a key role when high doses of ethanol are consumed by non-dependent subjects. This supports the notion that CRH system not only maintains the dependent state but also engages the transition to dependence.
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Affiliation(s)
- Andrea Cippitelli
- Laboratory of Clinical and Translational Studies, National Institute on Alcohol Abuse and Alcoholism (NIAAA), National Institutes of Health (NIH), Bethesda, MD 20892-1108, USA.
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Ripley TL, Stephens DN. Critical thoughts on current rodent models for evaluating potential treatments of alcohol addiction and withdrawal. Br J Pharmacol 2011; 164:1335-56. [PMID: 21470204 PMCID: PMC3229765 DOI: 10.1111/j.1476-5381.2011.01406.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2010] [Revised: 02/21/2011] [Accepted: 02/24/2011] [Indexed: 12/27/2022] Open
Abstract
Despite years of neurobiological research that have helped to identify potential therapeutic targets, we do not have a reliable pharmacological treatment for alcoholism. There are a range of possible explanations for this failure, including arguments that alcoholism is a spectrum disorder and that different population subtypes may respond to different treatments. This view is supported by categorisations such as early- and late-onset alcoholism, whilst multifactorial genetic factors may also alter responsivity to pharmacological agents. Furthermore, experience of alcohol withdrawal may play a role in future drinking in a way that may distinguish alcoholism from other forms of addiction. Additionally, our neurobiological models, based largely upon results from rodent studies, may not mimic specific aspects of the human condition and may reflect different underlying phenomena and biological processes from the clinical pattern. As a result, potential treatments may be targeting inappropriate aspects of alcohol-related behaviours. Instead, we suggest a more profitable approach is (a) to identify well-defined intermediate behavioural phenotypes in human experimental models that reflect defined aspects of the human clinical disorder and (b) to develop animal models that are homologous with those phenotypes in terms of psychological processes and underlying neurobiological mechanisms. This review describes an array of animal models currently used in the addiction field and what they tell us about alcoholism. We will then examine how established pharmacological agents have been developed using only a limited number of these models, before describing some alternative novel approaches to achieving homology between animal and human experimental measures.
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Affiliation(s)
- Tamzin L Ripley
- School of Psychology, University of Sussex, Falmer, Brighton, UK.
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Heilig M, Thorsell A, Sommer WH, Hansson AC, Ramchandani VA, George DT, Hommer D, Barr CS. Translating the neuroscience of alcoholism into clinical treatments: from blocking the buzz to curing the blues. Neurosci Biobehav Rev 2010; 35:334-44. [PMID: 19941895 PMCID: PMC2891917 DOI: 10.1016/j.neubiorev.2009.11.018] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2009] [Revised: 11/16/2009] [Accepted: 11/18/2009] [Indexed: 11/16/2022]
Abstract
Understanding the pathophysiology of addictive disorders is critical for development of new treatments. A major focus of addiction research has for a long time been on systems that mediate acute positively reinforcing effects of addictive drugs, most prominently the mesolimbic dopaminergic (DA) system and its connections. This research line has been successful in shedding light on the physiology of both natural and drug reward, but has not led to therapeutic breakthroughs. The role of classical reward systems is perhaps least clear in alcohol addiction. Here, recent work is summarized that points to some clinically important conclusions. First, important pharmacogenetic differences exist with regard to positively reinforcing effects of alcohol and the ability of this drug to activate classical reward pathways. This offers an opportunity for personalized treatment approaches in alcoholism. Second, brain stress and fear systems become pathologically activated in later stages of alcoholism and their activation is a major influence in escalation of alcohol intake, sensitization of stress responses, and susceptibility to relapse. These findings offer a new category of treatment mechanisms. Corticotropin-releasing hormone (CRH) signaling through CRH1 receptors is a major candidate target in this category, but recent data indicate that antagonists for substance P (SP) neurokinin 1 (NK1) receptors may have a similar potential.
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Affiliation(s)
- Markus Heilig
- Laboratory of Clinical and Translational Studies, National Inst. on Alcohol Abuse and Alcoholism, National Inst of Health, Bethesda, MD, United States.
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Crabbe JC, Phillips TJ, Belknap JK. The complexity of alcohol drinking: studies in rodent genetic models. Behav Genet 2010; 40:737-50. [PMID: 20552264 DOI: 10.1007/s10519-010-9371-z] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2010] [Accepted: 05/22/2010] [Indexed: 02/01/2023]
Abstract
Risk for alcohol dependence in humans has substantial genetic contributions. Successful rodent models generally attempt to address only selected features of the human diagnosis. Most such models target the phenotype of oral administration of alcohol solutions, usually consumption of or preference for an alcohol solution versus water. Data from rats and mice for more than 50 years have shown genetic influences on preference drinking and related phenotypes. This paper summarizes some key findings from that extensive literature. Much has been learned, including the genomic location and possible identity of several genes influencing preference drinking. We report new information from congenic lines confirming QTLs for drinking on mouse chromosomes 2 and 9. There are many strengths of the various phenotypic assays used to study drinking, but there are also some weaknesses. One major weakness, the lack of drinking excessively enough to become intoxicated, has recently been addressed with a new genetic animal model, mouse lines selectively bred for their high and intoxicating blood alcohol levels after a limited period of drinking in the circadian dark. We report here results from a second replicate of that selection and compare them with the first replicate.
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Affiliation(s)
- John C Crabbe
- Portland Alcohol Research Center, Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR 97239, USA.
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Leeman RF, Heilig M, Cunningham CL, Stephens DN, Duka T, O'Malley SS. Ethanol consumption: how should we measure it? Achieving consilience between human and animal phenotypes. Addict Biol 2010; 15:109-24. [PMID: 20148775 DOI: 10.1111/j.1369-1600.2009.00192.x] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
There is only modest overlap in the most common alcohol consumption phenotypes measured in animal studies and those typically studied in humans. To address this issue, we identified a number of alcohol consumption phenotypes of importance to the field that have potential for consilience between human and animal models. These phenotypes can be broken down into three categories: (1) abstinence/the decision to drink or abstain; (2) the actual amount of alcohol consumed; and (3) heavy drinking. A number of suggestions for human and animal researchers are made in order to address these phenotypes and enhance consilience. Laboratory studies of the decision to drink or to abstain are needed in both human and animal research. In human laboratory studies, heavy or binge drinking that meets cut-offs used in epidemiological and clinical studies should be reported. Greater attention to patterns of drinking over time is needed in both animal and human studies. Individual differences pertaining to all consumption phenotypes should be addressed in animal research. Lastly, improved biomarkers need to be developed in future research for use with both humans and animals. Greater precision in estimating blood alcohol levels in the field, together with consistent measurement of breath/blood alcohol levels in human laboratory and animal studies, provides one means of achieving greater consilience of alcohol consumption phenotypes.
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Affiliation(s)
- Robert F Leeman
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT 06519, USA
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Björk K, Hansson AC, Sommer WH. Genetic Variation and Brain Gene Expression in Rodent Models of Alcoholism. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2010; 91:129-71. [DOI: 10.1016/s0074-7742(10)91005-2] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Functional CRH variation increases stress-induced alcohol consumption in primates. Proc Natl Acad Sci U S A 2009; 106:14593-8. [PMID: 19706546 DOI: 10.1073/pnas.0902863106] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Corticotropin-releasing factor (CRF), encoded by the CRH gene, is a key integrator of stress responses, and, as such, CRH gene variation may contribute to individual differences in susceptibility to stress-related pathology. In rhesus macaques, a single nucleotide polymorphism (SNP) is found within the CRH promoter (-248C--> T). Here, we assessed whether this variant influenced stress responding and, because increased CRF system activity drives alcohol drinking in rodents, we examined whether it predicted voluntary alcohol consumption as a function of prior stress exposure. Using a hypothalamic nuclear extract, we showed that the -248 T allele resulted in increased DNA protein interactions relative to the C allele. In vitro, the T allele resulted in CRH promoter activity that was higher following both stimulation with forskolin and treatment with dexamethasone. Endocrine and behavioral responses to social separation stress (release of ACTH and cortisol, and suppression of environmental exploration, respectively) were higher among carriers of the T allele, particularly among those exposed to early adversity in the form of peer rearing. We also found that T allele carriers with a history of early life adversity consumed more alcohol in a limited-access paradigm. Our data suggest that CRH promoter variation that confers increased stress reactivity increases the risk for alcohol use disorders in stress-exposed individuals.
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Correia D, Ribeiro AF, Brunialti Godard AL, Boerngen-Lacerda R. Trait anxiety and ethanol: anxiolysis in high-anxiety mice and no relation to intake behavior in an addiction model. Prog Neuropsychopharmacol Biol Psychiatry 2009; 33:880-8. [PMID: 19394387 DOI: 10.1016/j.pnpbp.2009.04.015] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2009] [Revised: 04/15/2009] [Accepted: 04/16/2009] [Indexed: 10/20/2022]
Abstract
Anxiety has been proposed to play a role in the development of alcohol addiction, but the exact mechanisms by which this occurs remain unclear. The present study aimed to verify the relationship between basal anxiety levels, the anxiolytic-like effect of ethanol, and ethanol intake in mice exposed to an addiction model. In one experiment Swiss mice were characterized as high-anxiety (HA), medium-anxiety (MA), or non-anxiety (NA) in the elevated plus maze and then received saline or ethanol 2 g/kg acutely and chronically and were again exposed to the same test. NA mice decreased while MA mice maintained anxiety indices over the test days, regardless of treatment. HA ethanol-treated mice showed an anxiolytic-like effect, both acutely and chronically, while the saline-treated ones maintained their basal anxiety levels. In another experiment HA and MA mice were exposed to an addiction model based on a 3-bottle free-choice paradigm (ethanol 5% and 10%, and water) consisting of four phases: acquisition (10 weeks), withdrawal (W, 2 weeks), reexposure (2 weeks), and quinine-adulteration (2 weeks). HA and MA control mice had access only to water. Mice were characterized as addicted, heavy-drinker and light-drinker [Fachin-Scheit DJ, Ribeiro AF, Pigatto G, Goeldner FO, Boerngen-Lacerda R. Development of a mouse model of ethanol addiction: naltrexone efficacy in reducing consumption but not craving. J Neural Transm 2006;113:1305-21.]. No difference was observed between HA and MA mice in their preference for and intake of ethanol. No correlation was observed between ethanol intake, during any phase, and anxiety indices measured in the basal tests and during the W phase. The differences in anxiety indices between HA and MA groups persisted in the test performed during ethanol withdrawal, suggesting a "trait" anxiety profile. The data suggest that despite the fact that high anxiety trait levels are important for the anxiolytic-like effects of ethanol, they are not a determining factor for high ethanol intake, at least not under these experimental conditions.
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Affiliation(s)
- Diego Correia
- Department of Pharmacology, Universidade Federal do Paraná, Jardim das Américas, Curitiba, Paraná, CEP 81531-990; Brazil
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Neznanova O, Björk K, Rimondini R, Hansson AC, Hyytiä P, Heilig M, Sommer WH. Acute ethanol challenge inhibits glycogen synthase kinase-3beta in the rat prefrontal cortex. Int J Neuropsychopharmacol 2009; 12:275-80. [PMID: 19007447 PMCID: PMC2698134 DOI: 10.1017/s1461145708009620] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Intracellular signalling pathways emerge as key mediators of the molecular and behavioural effects of addictive drugs including ethanol. Previously, we demonstrated that the innate high ethanol preference in AA rats is driven by dysfunctional endocannabinoid signalling in the medial prefrontal cortex (mPFC). Here, we report that acute ethanol challenge, at a dose commonly regarded as reinforcing, strongly phosphorylates glycogen synthase kinase-3beta (GSK-3beta) in this region with corresponding increased phosphorylation of AKT, a major regulator of GSK-3beta. In the non-preferring counterpart ANA line we found a weaker, AKT-independent phosphorylation of GSK-3beta by ethanol. Furthermore, AA rats showed rapid and transient dephosphorylation of ERK1/2 upon acute ethanol challenge in the medial prefrontal cortex (mPFC) and to a lesser degree in the nucleus accumbens; ANA rats were completely non-responsive for this mechanism. Together, these results identify candidate pathways for mediating high ethanol preference and emphasize the importance of the mPFC in controlling this behaviour.
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Affiliation(s)
- Olga Neznanova
- Laboratory of Clinical and Translational Studies, NIAAA, National Institutes of Health, Bethesda, MD, USA
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A blocker of N- and T-type voltage-gated calcium channels attenuates ethanol-induced intoxication, place preference, self-administration, and reinstatement. J Neurosci 2008; 28:11712-9. [PMID: 18987207 DOI: 10.1523/jneurosci.3621-08.2008] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
There is a clear need for new therapeutics to treat alcoholism. Here, we test our hypothesis that selective inhibitors of neuronal calcium channels will reduce ethanol consumption and intoxication, based on our previous studies using knock-out mice and cell culture systems. We demonstrate that pretreatment with the novel mixed N-type and T-type calcium channel antagonist 1-(6,6-bis(4-fluorophenyl)hexyl)-4-(3,4,5-trimethoxybenzyl)piperazine (NP078585) reduced ethanol intoxication. NP078585 also attenuated the reinforcing and rewarding properties of ethanol, measured by operant self-administration and the expression of an ethanol conditioned place preference, and abolished stress-induced reinstatement of ethanol seeking. NP078585 did not affect alcohol responses in mice lacking N-type calcium channels. These results suggest that selective calcium channel inhibitors may be useful in reducing acute ethanol intoxication and alcohol consumption by human alcoholics.
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Gupta T, Syed YM, Revis AA, Miller SA, Martinez M, Cohn KA, Demeyer MR, Patel KY, Brzezinska WJ, Rhodes JS. Acute effects of acamprosate and MPEP on ethanol Drinking-in-the-Dark in male C57BL/6J mice. Alcohol Clin Exp Res 2008; 32:1992-8. [PMID: 18782337 DOI: 10.1111/j.1530-0277.2008.00787.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Recently, a simple procedure in mice, Drinking-in-the-Dark (DID), was hypothesized to have value for medication development for human alcoholism. In DID, mice are offered intermittent, limited access to ethanol over a series of days during the dark phase that results in rapid drinking to intoxication in predisposed genotypes. METHODS We measured the effects of acamprosate or MPEP, metabotropic glutamate 5 receptor (mGluR5) antagonist, on intake of 20% ethanol, plain tap water or 10% sugar water using the DID procedure in male C57BL/6J mice. RESULTS Acamprosate (100, 200, 300, or 400 mg/kg) dose dependently decreased ethanol drinking with 300 mg/kg reducing ethanol intake by approximately 20% without affecting intake of plain water or 10% sugar water. MPEP (1, 3, 5, 10, 20, or 40 mg/kg) was more potent than acamprosate with 20 mg/kg reducing ethanol intake by approximately 20% and for longer duration without affecting intake of plain water or 10% sugar water. CONCLUSIONS These results support the hypothesis that mGluR5 signaling plays a role in excessive ethanol intake in DID and suggest DID may have value for screening novel compounds that reduce overactive glutamate signaling for potential pharmaceutical treatment of excessive ethanol drinking behavior.
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Affiliation(s)
- Tripta Gupta
- Department of Psychology, The Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
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Sommer WH, Saavedra JM. Targeting brain angiotensin and corticotrophin-releasing hormone systems interaction for the treatment of mood and alcohol use disorders. J Mol Med (Berl) 2008; 86:723-8. [PMID: 18449521 DOI: 10.1007/s00109-008-0333-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2008] [Revised: 02/15/2008] [Accepted: 02/20/2008] [Indexed: 01/16/2023]
Abstract
The brain renin-angiotensin system (RAS) participates importantly in the regulation of endocrine, autonomic, and behavioral response to stress. Recent data indicate that central action of AT(1) receptor antagonists can reduce anxiety symptoms in experimental animals. Furthermore, central inhibition of RAS activity decreases ethanol intake in an animal model of alcoholism. Pathological anxiety responses and the development of substance dependence are both critically mediated through corticotrophin-releasing hormone (CRH) systems, and the RAS is positioned to interact both with hypothalamic as well as extrahypothalamic CRH systems. The thesis of this paper is that the RAS is part of the neurochemical dysregulation underlying negative affective states, anxiety disorders, and ethanol dependence and that medications targeting the RAS should be considered to augment the treatment of these disorders.
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Affiliation(s)
- Wolfgang H Sommer
- Laboratory of Clinical and Translational Studies, National Institute of Alcohol Abuse and Alcoholism, National Institutes of Health, 10 Center Drive, Bethesda, MD 20892-1108, USA.
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