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Becker HC, Lopez MF. Animal Models of Excessive Alcohol Consumption in Rodents. Curr Top Behav Neurosci 2024. [PMID: 38340255 DOI: 10.1007/7854_2024_461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2024]
Abstract
The development of animal models that demonstrate excessive levels of alcohol consumption has played an important role in advancing our knowledge about neurobiological underpinnings and environmental circumstances that engender such maladaptive behavior. The use of these preclinical models has also provided valuable opportunities for discovering new and novel therapeutic targets that may be useful in the treatment of alcohol use disorder (AUD). While no single model can fully capture the complexities of AUD, the goal is to develop animal models that closely approximate characteristics of heavy alcohol drinking in humans to enhance their translational value and utility. A variety of experimental approaches have been employed to produce the desired phenotype of interest-robust and reliable excessive levels of alcohol drinking. Here we provide an updated review of five animal models that are commonly used. The models entail procedural manipulations of scheduled access to alcohol (time of day, duration, frequency), periods of time when access to alcohol is withheld, and history of alcohol exposure. Specially, the models involve (a) scheduled access to alcohol, (b) scheduled periods of alcohol deprivation, (c) scheduled intermittent access to alcohol, (d) scheduled-induced polydipsia, and (e) chronic alcohol (dependence) and withdrawal experience. Each of the animal models possesses unique experimental features that engender excessive levels of alcohol consumption. Both advantages and disadvantages of each model are described along with discussion of future work to be considered in developing more optimal models. Ultimately, the validity and utility of these models will lie in their ability to aid in the discovery of new and novel potential therapeutic targets as well as serve as a platform to evaluate treatment strategies that effectively reduce excessive levels of alcohol consumption associated with AUD.
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Affiliation(s)
- Howard C Becker
- Charleston Alcohol Research Center, Medical University of South Carolina, Charleston, SC, USA.
- Departments of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, SC, USA.
- Departments of Psychiatry and Neuroscience, Medical University of South Carolina, Charleston, SC, USA.
- RHJ Veterans Administration Health Care System, Medical University of South Carolina, Charleston, SC, USA.
| | - Marcelo F Lopez
- Charleston Alcohol Research Center, Medical University of South Carolina, Charleston, SC, USA
- Departments of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, SC, USA
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Wong K, Wang ZC, Patarino M, Baskin B, Lee SJ, Schindler AG. Socially Integrated Polysubstance (SIP) system: An open-source solution for continuous monitoring of polysubstance fluid intake in group housed mice. ADDICTION NEUROSCIENCE 2023; 7:10.1016/j.addicn.2023.100101. [PMID: 37560335 PMCID: PMC10411158 DOI: 10.1016/j.addicn.2023.100101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 08/11/2023]
Abstract
Despite impressive results from neuroscience research using rodent models, there is a paucity of successful translation from preclinical findings to effective pharmacological interventions for treatment of substance use disorder (SUD) in humans. One potential reason for lack of translation from animal models is difficulty in accurately replicating the lived experience of people who use drugs. Aspects of substance use in humans that are often not modeled in animal research include but are not limited to 1) voluntary timing and frequency of substance intake, 2) social environment during substance use, and 3) access to multiple substances and multiple concentrations of each substance. Critically, existing commercial equipment that allows for social housing and voluntary polysubstance use (e.g., home cage monitoring system) is prohibitively expensive and no open-source solutions exist. With these goals in mind, here we detail development of the Socially Integrated Polysubstance (SIP) system, an open-source and lower cost solution that allows for group housed rodents to self-administer multiple substances with continuous monitoring and measurement. In our current setup, each SIP cage contains four drinking stations, and each station is equipped with a RFID sensor and sipper tube connected to a unique fluid reservoir. Using this system, we can track which animal (implanted with unique RFID transponder) visits which drinking location and the amount they drink during each visit (in 20 ul increments). Using four flavors of Kool-Aid, here we demonstrate that the SIP system is reliable and accurate with high temporal resolution for long term monitoring of substance intake and behavior tracking in a social environment. The SIP cage system is a first step towards designing an accessible and flexible rodent model of substance use that more closely resembles the experience of people who use drugs.
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Affiliation(s)
- Katrina Wong
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA, USA 98195
- VA Northwest Geriatric Research Education and Clinical Center, VA Puget Sound Health Care System, Seattle, WA 98108, USA
| | - Ziheng Christina Wang
- VA Northwest Geriatric Research Education and Clinical Center, VA Puget Sound Health Care System, Seattle, WA 98108, USA
| | - Makenzie Patarino
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA, USA 98195
- Graduate Program in Neuroscience, University of Washington, Seattle, WA, USA 98195
- VA Northwest Geriatric Research Education and Clinical Center, VA Puget Sound Health Care System, Seattle, WA 98108, USA
| | - Britahny Baskin
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA, USA 98195
- Graduate Program in Neuroscience, University of Washington, Seattle, WA, USA 98195
- VA Northwest Geriatric Research Education and Clinical Center, VA Puget Sound Health Care System, Seattle, WA 98108, USA
| | - Suhjung Janet Lee
- VA Northwest Geriatric Research Education and Clinical Center, VA Puget Sound Health Care System, Seattle, WA 98108, USA
| | - Abigail G. Schindler
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA, USA 98195
- Graduate Program in Neuroscience, University of Washington, Seattle, WA, USA 98195
- VA Northwest Geriatric Research Education and Clinical Center, VA Puget Sound Health Care System, Seattle, WA 98108, USA
- VA Northwest Mental Illness Research, Education, and Clinical Center, VA Puget Sound Health Care System, Seattle, WA 98108, USA
- Department of Medicine, University of Washington, Seattle, WA 98195, USA
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Marchant NJ, McDonald AJ, Matsuzaki R, van Mourik Y, Schetters D, De Vries TJ. Rats choose alcohol over social reward in an operant choice procedure. Neuropsychopharmacology 2023; 48:585-593. [PMID: 36109596 PMCID: PMC9938232 DOI: 10.1038/s41386-022-01447-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 08/24/2022] [Accepted: 08/26/2022] [Indexed: 11/09/2022]
Abstract
The interaction between social factors and alcohol addiction is complex, with potential for both positive and negative contributions to drug use and abstinence. Positive social connections are an important component in successful abstinence, and yet the social context of alcohol use can also lead to relapse. Recently it was shown that rats overwhelmingly choose social reward over methamphetamine, cocaine, and heroin in a discrete choice procedure, and that prolonged choice for social reward attenuates incubation of drug craving. The extent to which this effect generalises to rats trained to self-administer alcohol is not known. In this study we aimed to test the effect of social reward on choice for alcohol in male and female rats. We first validated social reward self-administration in both male and female Long-Evans rats, and found that 60 s access to a social partner of the same sex can serve as an operant reinforcer. Next we trained rats to self-administer both social reward and alcohol (20% ethanol in water), and then used discrete choice trial based tests to determine whether there is a choice preference for alcohol or social reward. Our main finding is that both male and female rats showed persistent choice for alcohol over social reward, with only minor differences between the sexes. We also show that choice for alcohol could be reduced via increased response requirement for alcohol, pre-choice alcohol exposure, and also decreasing the alcohol percentage. This study shows that preference for social rewards over drugs may not generalise to rats self-administering alcohol, and we describe several conditions where choice for social reward can be developed. This study highlights the important contribution of social factors to alcohol abuse, and future studies can investigate the neurobiology underlying a shift in preference from alcohol to social rewards.
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Affiliation(s)
- Nathan J Marchant
- Department of Anatomy & Neurosciences, Amsterdam UMC location Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.
- Compulsivity Impulsivity and Attention, Amsterdam Neuroscience, Amsterdam, The Netherlands.
| | - Allison J McDonald
- Department of Anatomy & Neurosciences, Amsterdam UMC location Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
- Compulsivity Impulsivity and Attention, Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - Rie Matsuzaki
- Department of Anatomy & Neurosciences, Amsterdam UMC location Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
- Compulsivity Impulsivity and Attention, Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - Yvar van Mourik
- Department of Anatomy & Neurosciences, Amsterdam UMC location Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
- Compulsivity Impulsivity and Attention, Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - Dustin Schetters
- Department of Anatomy & Neurosciences, Amsterdam UMC location Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
- Compulsivity Impulsivity and Attention, Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - Taco J De Vries
- Department of Anatomy & Neurosciences, Amsterdam UMC location Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
- Compulsivity Impulsivity and Attention, Amsterdam Neuroscience, Amsterdam, The Netherlands
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Körber C, Sommer WH. From ensembles to meta-ensembles: Specific reward encoding by correlated network activity. Front Behav Neurosci 2022; 16:977474. [PMID: 36177094 PMCID: PMC9513968 DOI: 10.3389/fnbeh.2022.977474] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Accepted: 08/15/2022] [Indexed: 11/29/2022] Open
Abstract
Neuronal ensembles are local, sparsely distributed populations of neurons that are reliably re-activated by a specific stimulus, context or task. Such discrete cell populations can be defined either functionally, by electrophysiological recordings or in vivo calcium imaging, or anatomically, using the expression of markers such as the immediate early gene cFos. A typical example of tasks that involve the formation of neuronal ensembles is reward learning, such as the cue-reward pairing during operant conditioning. These ensembles are re-activated during cue-presentation and increasing evidence suggests that this re-activation is the neurophysiological basis for the execution of reward-seeking behavior. Whilst the pursuit of rewards is a common daily activity, it is also related to the consumption of drugs, such as alcohol, and may result in problematic behaviors including addiction. Recent research has identified neuronal ensembles in several reward-related brain regions that control distinct aspects of a conditioned response, e.g., contextual information about the availability of a specific reward or the actions needed to retrieve this reward under the given circumstances. Here, we review studies using the activity marker cFos to identify and characterize neuronal ensembles related to alcohol and non-drug rewards with a special emphasis on the discrimination between different rewards by meta-ensembles, i.e., by dynamic co-activation of multiple ensembles across different brain areas.
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Affiliation(s)
- Christoph Körber
- Department of Functional Neuroanatomy, Institute of Anatomy and Cell Biology, Heidelberg University, Heidelberg, Germany
| | - Wolfgang H Sommer
- Medical Faculty Mannheim, Institute of Psychopharmacology, Central Institute of Mental Health, Heidelberg University, Mannheim, Germany
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From concepts to treatment: a dialog between a preclinical researcher and a clinician in addiction medicine. Transl Psychiatry 2022; 12:401. [PMID: 36130939 PMCID: PMC9492712 DOI: 10.1038/s41398-022-02177-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 09/06/2022] [Accepted: 09/12/2022] [Indexed: 11/08/2022] Open
Abstract
The debate surrounding the brain disease model and the associated questioning of the relevance of animal models is polarizing the field of addiction, and tends to widen the gap between preclinical research and addiction medicine. Here, we aimed at bridging this gap by establishing a dialog between a preclinical researcher and a clinician in addiction medicine. Our objective was to evaluate animal models and the neuroscientific conceptualization of addiction in light of alcohol or drug dependence and treatment in patients struggling with an addiction. We sought to determine how preclinical research influenced addiction medicine over past decades, and reciprocally, what can preclinical researchers learn from addiction medicine that could lead to more effective approaches. In this dialog, we talk about the co-evolution of addiction concepts and treatments from neuroscientific and medical perspectives. This dialog illustrates the reciprocal influences and mutual enrichment between the two disciplines and reveals that, although preclinical research might not produce new pharmacotherapies, it does shape the theoretical conceptualization of addiction and could thereby contribute to the implementation of therapeutic approaches.
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Vandaele Y, Ahmed SH. Choosing between cocaine and sucrose under the influence: testing the effect of cocaine tolerance. Psychopharmacology (Berl) 2022; 239:1053-1063. [PMID: 34596725 DOI: 10.1007/s00213-021-05987-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 09/14/2021] [Indexed: 01/05/2023]
Abstract
RATIONALE Cocaine use not only depends on the reinforcing properties of the drug, but also on its pharmacological effects on alternative nondrug activities. In animal models investigating choice between cocaine and alternative sweet rewards, the latter influence can have a dramatic impact on choice outcomes. When choosing under cocaine influence is prevented by imposing sufficiently long intervals between choice trials, animals typically prefer the sweet reward. However, when choosing under the drug influence is permitted, animals shift their preference in favor of cocaine. OBJECTIVES We previously hypothesized that this preference shift is mainly due to a direct suppression of responding for sweet reward by cocaine pharmacological effects. Here we tested this hypothesis by making rats tolerant to this drug-induced behavioral suppression. RESULTS Contrary to our expectation, tolerance did not prevent rats from shifting their preference to cocaine when choosing under the influence. CONCLUSION Thus, other mechanisms must be invoked to explain the influence of cocaine intoxication on choice outcomes.
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Affiliation(s)
| | - S H Ahmed
- Institut Des Maladies Neurodégénératives, Université de Bordeaux, Bordeaux, France.,Institut Des Maladies Neurodégénératives, CNRS, Bordeaux, France
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Sommer WH, Canals S, Bifone A, Heilig M, Hyytiä P. From a systems view to spotting a hidden island: A narrative review implicating insula function in alcoholism. Neuropharmacology 2022; 209:108989. [PMID: 35217032 DOI: 10.1016/j.neuropharm.2022.108989] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 01/30/2022] [Accepted: 02/07/2022] [Indexed: 12/31/2022]
Abstract
Excessive use of alcohol promotes the development of alcohol addiction, but the understanding of how alcohol-induced brain alterations lead to addiction remains limited. To further this understanding, we adopted an unbiased discovery strategy based on the principles of systems medicine. We used functional magnetic resonance imaging data from patients and animal models of alcohol addiction-like behaviors, and developed mathematical models of the 'relapse-prone' network states to identify brain sites and functional networks that can be selectively targeted by therapeutic interventions. Our systems level, non-local, and largely unbiased analyses converged on a few well-defined brain regions, with the insula emerging as one of the most consistent finding across studies. In proof-of-concept experiments we were able to demonstrate that it is possible to guide network dynamics towards increased resilience in animals but an initial translation into a clinical trial targeting the insula failed. Here, in a narrative review, we summarize the key experiments, methodological developments and knowledge gained from this completed round of a discovery cycle moving from identification of 'relapse-prone' network states in humans and animals to target validation and intervention trial. Future concerted efforts are necessary to gain a deeper understanding of insula function a in a state-dependent, circuit-specific and cell population perspective, and to develop the means for insula-directed interventions, before therapeutic targeting of this structure may become possible.
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Affiliation(s)
- Wolfgang H Sommer
- Institute of Psychopharmacology, Central Institute of Mental Health, University of Heidelberg, Medical Faculty Mannheim, Bethania Hospital for Psychiatry, Psychosomatics, and Psychotherapy, Greifswald, Germany.
| | - Santiago Canals
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas and Universidad Miguel Hernández, 03550, Sant Joan d'Alacant, Spain
| | - Angelo Bifone
- Department of Molecular Biotechnology and Health Sciences, University of Torino, Istituto Italiano di Tecnologia, Center for Sustainable Future Technologies, Torino, Italy
| | - Markus Heilig
- Center for Social and Affective Neuroscience, Linköping University and Dept. of Psychiatry, Linköping Univ. Hospital, S-581 85, Linköping, Sweden
| | - Petri Hyytiä
- Department of Pharmacology, Faculty of Medicine, University of Helsinki, Finland
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Vanderschuren LJMJ, Ahmed SH. Animal Models of the Behavioral Symptoms of Substance Use Disorders. Cold Spring Harb Perspect Med 2021; 11:cshperspect.a040287. [PMID: 32513674 PMCID: PMC8327824 DOI: 10.1101/cshperspect.a040287] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
To more effectively manage substance use disorders, it is imperative to understand the neural, genetic, and psychological underpinnings of addictive behavior. To contribute to this understanding, considerable efforts have been made to develop translational animal models that capture key behavioral characteristics of addiction on the basis of DSM5 criteria of substance use disorders. In this review, we summarize empirical evidence for the occurrence of addiction-like behavior in animals. These symptoms include escalation of drug use, neurocognitive deficits, resistance to extinction, exaggerated motivation for drugs, increased reinstatement of drug seeking after extinction, preference for drugs over nondrug rewards, and resistance to punishment. The occurrence of addiction-like behavior in laboratory animals has opened the opportunity to investigate the neural, genetic, and psychological background of key aspects of addiction, which may ultimately contribute to the prevention and treatment of substance use disorders.
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Affiliation(s)
- Louk J M J Vanderschuren
- Department of Animals in Science and Society, Division of Behavioural Neuroscience, Faculty of Veterinary Medicine, Utrecht University, 3584 CM Utrecht, the Netherlands
| | - Serge H Ahmed
- Université de Bordeaux, Bordeaux Neurocampus, Institut des Maladies Neurodégénératives, CNRS UMR 5293, F-33000 Bordeaux, France
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Alaux‐Cantin S, Alarcon R, Audegond C, Simon O'Brien E, Martinetti MP, Ahmed SH, Nalpas B, Perney P, Naassila M. Sugar, a powerful substitute for ethanol in ethanol postdependent rats: Relevance for clinical consideration? Addict Biol 2021; 26:e13023. [PMID: 33559189 DOI: 10.1111/adb.13023] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 01/10/2021] [Accepted: 01/29/2021] [Indexed: 01/01/2023]
Abstract
Sugar has been shown to be a powerful substitute for drugs in preclinical studies on addiction. However, the link between sugar intake and alcohol use disorder (AUD) is poorly understood. We assessed the influence of sucrose on ethanol drinking in both nondependent (ND) and dependent (D) Long-Evans rats during acute withdrawal using the postdependent state model. Ethanol (10%-40%) and sucrose (1%-4%) solutions were offered in an operant paradigm either independently or concurrently under ratio schedules of reinforcement. We showed that D rats displayed an enhanced motivation for both 10% ethanol solution (10E) and 4% sucrose solution (4S) as compared with ND rats, and a clear preference for 4S was observed in both groups. During acute withdrawal, D rats showed a strong motivation for 30% ethanol (30E), even when adulterated with quinine, but still preferred 4S despite the fact that a high level of negative reinforcement could be expected. However, when a premix solution (30E4S) was offered concurrently with 4S, the preference for 4S was lost in D animals, which consumed as much premix as 4S, whereas ND animals displayed preference for 4S. Altogether, those results suggest that reinforcing properties of sucrose surpass those of ethanol in D rats under acute withdrawal, which indicates that sugar is a powerful substitute for ethanol. Our results suggest that craving for sugar may be increased in AUD patients during withdrawal and raise the issue of dependence transfer from alcohol to sugar.
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Affiliation(s)
- Stéphanie Alaux‐Cantin
- INSERM UMR1247, Groupe de Recherche sur l'Alcool et les Pharmacodépendances (GRAP) Université de Picardie Jules Verne Amiens France
| | - Régis Alarcon
- Service d'Addictologie Centre Hospitalier Universitaire Caremeau Nîmes France
| | - Clément Audegond
- INSERM UMR1247, Groupe de Recherche sur l'Alcool et les Pharmacodépendances (GRAP) Université de Picardie Jules Verne Amiens France
| | - Emmanuelle Simon O'Brien
- INSERM UMR1247, Groupe de Recherche sur l'Alcool et les Pharmacodépendances (GRAP) Université de Picardie Jules Verne Amiens France
| | - Margaret P. Martinetti
- INSERM UMR1247, Groupe de Recherche sur l'Alcool et les Pharmacodépendances (GRAP) Université de Picardie Jules Verne Amiens France
- Department of Psychology The College of New Jersey Ewing New Jersey USA
| | - Serge H. Ahmed
- Institut des Maladies Neurodégénératives, UMR 5293 Université de Bordeaux Bordeaux France
| | - Bertrand Nalpas
- Service d'Addictologie Centre Hospitalier Universitaire Caremeau Nîmes France
| | - Pascal Perney
- Service d'Addictologie Centre Hospitalier Universitaire Caremeau Nîmes France
| | - Mickael Naassila
- INSERM UMR1247, Groupe de Recherche sur l'Alcool et les Pharmacodépendances (GRAP) Université de Picardie Jules Verne Amiens France
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Marti‐Prats L, Belin‐Rauscent A, Fouyssac M, Puaud M, Cocker PJ, Everitt BJ, Belin D. Baclofen decreases compulsive alcohol drinking in rats characterized by reduced levels of GAT-3 in the central amygdala. Addict Biol 2021; 26:e13011. [PMID: 33527681 PMCID: PMC8603926 DOI: 10.1111/adb.13011] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 01/12/2021] [Accepted: 01/14/2021] [Indexed: 11/29/2022]
Abstract
While most individuals with access to alcohol drink it recreationally, some vulnerable individuals eventually lose control over their intake and progressively develop compulsive alcohol drinking and decreased interest in alternative sources of reinforcement, two key features of addiction. The neural and molecular mechanisms underlying this vulnerability to switch from controlled to compulsive alcohol intake have not been fully elucidated. It has been shown that rats having reduced levels of expression of the gamma-aminobutyric acid (GABA) transporter, GAT-3, in the amygdala tend to persist in seeking and drinking alcohol even when adulterated with quinine, suggesting that pharmacological interventions aimed at restoring GABA homeostasis in these individuals may provide a targeted treatment to limit compulsive alcohol drinking. Here, we tested the hypothesis that the GABAB receptor agonist baclofen, which decreases GABA release, specifically reduces compulsive alcohol drinking in vulnerable individuals. In a large cohort of Sprague-Dawley rats allowed to drink alcohol under an intermittent two-bottle choice procedure, a cluster of individuals was identified that persisted in drinking alcohol despite adulteration with quinine or when an alternative ingestive reinforcer, saccharin, was available. In these rats, which were characterized by decreased GAT-3 mRNA levels in the central amygdala, acute baclofen administration (1.5 mg/kg, intraperitoneal) resulted in a decrease in compulsive drinking. These results indicate that low GAT-3 mRNA levels in the central amygdala may represent an endophenotype of vulnerability to develop a compulsive drinking of alcohol that is shown here to be mitigated by baclofen.
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Affiliation(s)
| | | | - Maxime Fouyssac
- Department of Psychology University of Cambridge Cambridge UK
| | - Mickaël Puaud
- Department of Psychology University of Cambridge Cambridge UK
| | - Paul J Cocker
- Department of Psychology University of Cambridge Cambridge UK
| | - Barry J Everitt
- Department of Psychology University of Cambridge Cambridge UK
| | - David Belin
- Department of Psychology University of Cambridge Cambridge UK
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Hogarth L. Addiction is driven by excessive goal-directed drug choice under negative affect: translational critique of habit and compulsion theory. Neuropsychopharmacology 2020; 45:720-735. [PMID: 31905368 PMCID: PMC7265389 DOI: 10.1038/s41386-020-0600-8] [Citation(s) in RCA: 127] [Impact Index Per Article: 31.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 12/09/2019] [Accepted: 12/18/2019] [Indexed: 01/21/2023]
Abstract
Drug addiction may be a goal-directed choice driven by excessive drug value in negative affective states, a habit driven by strong stimulus-response associations, or a compulsion driven by insensitivity to costs imposed on drug seeking. Laboratory animal and human evidence for these three theories is evaluated. Excessive goal theory is supported by dependence severity being associated with greater drug choice/economic demand. Drug choice is demonstrably goal-directed (driven by the expected value of the drug) and can be augmented by stress/negative mood induction and withdrawal-effects amplified in those with psychiatric symptoms and drug use coping motives. Furthermore, psychiatric symptoms confer risk of dependence, and coping motives mediate this risk. Habit theory of addiction has weaker support. Habitual behaviour seen in drug-exposed animals often does not occur in complex decision scenarios, or where responding is rewarded, so habit is unlikely to explain most human addictive behaviour where these conditions apply. Furthermore, most human studies have not found greater propensity to habitual behaviour in drug users or as a function of dependence severity, and the minority that have can be explained by task disengagement producing impaired explicit contingency knowledge. Compulsion theory of addiction also has weak support. The persistence of punished drug seeking in animals is better explained by greater drug value (evinced by the association with economic demand) than by insensitivity to costs. Furthermore, human studies have provided weak evidence that propensity to discount cost imposed on drug seeking is associated with dependence severity. These data suggest that human addiction is primarily driven by excessive goal-directed drug choice under negative affect, and less by habit or compulsion. Addiction is pathological because negative states powerfully increase expected drug value acutely outweighing abstinence goals.
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Affiliation(s)
- Lee Hogarth
- School of Psychology, University of Exeter, Washington Singer Building, Perry Road, Exeter, EX4 4QG, UK.
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12
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Marcolin ML, Baumbach JL, Hodges TE, McCormick CM. The effects of social instability stress and subsequent ethanol consumption in adolescence on brain and behavioral development in male rats. Alcohol 2020; 82:29-45. [PMID: 31465790 DOI: 10.1016/j.alcohol.2019.08.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 07/25/2019] [Accepted: 08/15/2019] [Indexed: 12/30/2022]
Abstract
Excessive drinking in adolescence continues to be a problem, and almost a quarter of young Canadians have reported consuming five or more alcoholic drinks in one occasion in recent surveys. The consequences of such drinking may be more pronounced when commenced in adolescence, given the ongoing brain development during this period of life. Here, we investigated the consequences of 3 weeks' intermittent access to ethanol in mid-adolescence to early adulthood in rats, and the extent to which a stress history moderated the negative consequences of ethanol access. In experiment 1, male rats that underwent adolescent social instability stress (SS; daily 1 h isolation + return to unfamiliar cage partner every day from postnatal day [PND] 30-45) did not differ from control (CTL) rats in intake of 10% ethanol sweetened with 0.1% saccharin (access period; PND 47-66). Ethanol drinking reduced proteins relevant for synaptic plasticity (αCaMKII, βCaMKII, and PSD-95) in the dorsal hippocampus, and in CTL rats only in the prefrontal cortex (αCaMKII and PSD 95), attenuating the difference between CTL and SS rats in the water-drinking group. In experiment 2, ethanol also attenuated the difference between SS and CTL rats in a social interaction test by reducing social interaction in SS rats; CTL rats, however, had a higher intake of ethanol than did SS rats during the access period. Ethanol drinking reduced baseline and fear recall recovery concentrations of corticosterone relative to those exposed only to water, although there was no effect of either ethanol or stress history on fear conditioning. Ethanol drinking did not influence intake after 9 days of withdrawal; however, ethanol-naïve SS rats drank more than did CTL rats when given a 24-h access in adulthood. These results reveal a complex relationship between stress history and ethanol intake in adolescence on outcomes in adulthood.
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Affiliation(s)
- Marina L Marcolin
- Department of Biological Sciences, Brock University, St. Catharines, Ontario, L2S 3A1, Canada
| | - Jennet L Baumbach
- Department of Psychology, Brock University, St. Catharines, Ontario, L2S 3A1, Canada
| | - Travis E Hodges
- Department of Psychology, Brock University, St. Catharines, Ontario, L2S 3A1, Canada
| | - Cheryl M McCormick
- Department of Psychology, Brock University, St. Catharines, Ontario, L2S 3A1, Canada; Centre for Neuroscience, Brock University, St. Catharines, Ontario, L2S 3A1, Canada.
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Reduced ethanol self-administration in rats produced by the introduction of a high value non-drug alternative reinforcer. Pharmacol Biochem Behav 2019; 184:172744. [PMID: 31351907 DOI: 10.1016/j.pbb.2019.172744] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 07/01/2019] [Accepted: 07/24/2019] [Indexed: 11/23/2022]
Abstract
Previous studies have shown that providing rats with a non-drug alternative in a choice situation can reduce ethanol taking in rats. There is also evidence that brief experience with non-drug reinforcers can reduce the reinforcing effects of drugs like cocaine, even when those non-drug alternatives are not pitted against the drug in a choice procedure. The goal of the present experiment was to determine whether experience with sucrose - a high value non-drug reinforcer in rats - in a non-choice situation would reduce ethanol's reinforcing effects, as measured within a behavioral economic framework. In a first phase, separate groups of rats worked on fixed-ratio schedules for ethanol, sucrose, or ethanol plus sucrose (during separate components within a session). In a second phase, all rats worked for ethanol and sucrose during alternating components. The introduction of sucrose components in the second phase to the group that previously only had experience with ethanol caused a significant decrease in ethanol self-administration. There was also a significant interaction whereby the effect of phase on the elasticity of demand for ethanol differed between the group that only had ethanol and the group that had ethanol plus sucrose in the first phase. These results indicate that a high value non-drug alternative reinforcer can reduce ethanol's reinforcing effects even when that alternative is not available at the time when ethanol is available. These findings suggest that treatments aiming to increase exposure to non-alcohol sources of reinforcement might be beneficial in reducing alcohol drinking.
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Funk D, Coen K, Tamadon S, Lê AD. Effect of chronic alcohol vapor exposure on reinstatement of alcohol seeking induced by U50,488. Neuropharmacology 2019; 148:210-219. [PMID: 30659838 DOI: 10.1016/j.neuropharm.2019.01.017] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Revised: 01/10/2019] [Accepted: 01/15/2019] [Indexed: 02/07/2023]
Abstract
Alcohol dependence and stress are associated with relapse to alcohol during abstinence, but the underlying mechanisms are poorly understood. Kappa opioid receptors (KOR) are involved in alcohol reward and in the effects of stress. Previously, in non-dependent rats, we showed that KOR in the bed nucleus of the stria terminalis (BNST) mediate reinstatement of alcohol seeking induced by the selective KOR agonist U50,488. Here, we determine the effects of chronic, intermittent exposure to alcohol vapor on U50,488-induced reinstatement of alcohol seeking. We also study brain mechanisms involved using the neuronal activity marker Fos and phosphorylated p38 MAPK (p-p38), an intracellular messenger implicated in the effects of KOR stimulation. We trained male Long-Evans rats to self-administer alcohol (12% w/v) and exposed them to alcohol vapor (14 h vapor/10 h air) daily for 24 d or to the control condition, extinguished alcohol-reinforced responding and determined the dose response for U50,488-induced reinstatement. We then determined the effects of vapor exposure on U50,488-induced Fos and p-p38 expression. Vapor-exposed rats were more sensitive to U50,488-induced reinstatement. U50,488 increased Fos expression in brain areas involved in stress-induced relapse, and Fos activation in the ventral BNST was greater in vapor exposed rats. Vapor exposed rats had increased basal p-p38 expression in the dorsal BNST, LC and NTS. Our findings suggest that changes in the neuronal responses to KOR stimulation in the ventral BNST may be involved in the increased sensitivity to U50,488 accompanying dependence.
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Affiliation(s)
- Douglas Funk
- Neurobiology of Alcohol Laboratory, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Canada.
| | - Kathleen Coen
- Neurobiology of Alcohol Laboratory, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Canada
| | - Sahar Tamadon
- Neurobiology of Alcohol Laboratory, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Canada
| | - A D Lê
- Neurobiology of Alcohol Laboratory, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Canada; Department of Pharmacology and Toxicology, University of Toronto, Canada; Department of Psychiatry, University of Toronto, Canada
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Hogarth L, Hardy L, Bakou A, Mahlberg J, Weidemann G, Cashel S, Moustafa AA. Negative Mood Induction Increases Choice of Heroin Versus Food Pictures in Opiate-Dependent Individuals: Correlation With Self-Medication Coping Motives and Subjective Reactivity. Front Psychiatry 2019; 10:274. [PMID: 31156470 PMCID: PMC6529569 DOI: 10.3389/fpsyt.2019.00274] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Accepted: 04/10/2019] [Indexed: 01/29/2023] Open
Abstract
Acute growth in negative affect is thought to play a major role in triggering relapse in opiate-dependent individuals. Consistent with this view, three lab studies have demonstrated that negative mood induction increases opiate craving in opiate-dependent individuals. The current study sought to confirm these effects with a behavioral measure of heroin seeking, and test whether the effect is associated with self-reported opiate use to cope with negative affect and subjective reactivity to mood induction. Participants were heroin-dependent individuals engaged with treatment services (n = 47) and control participants (n = 25). Heroin users completed a questionnaire assessing reasons for using heroin: negative affect, social pressure, and cued craving. Baseline heroin choice was measured by preference to enlarge heroin versus food thumbnail pictures in two-alternative forced-choice trials. Negative mood was then induced by depressive statements and music before heroin choice was tested again. Subjective reactivity was indexed by negative and positive mood reported at the pre-induction to post-test timepoints. Heroin users chose heroin images more frequently than controls overall ( p = .001) and showed a negative mood-induced increase in heroin choice compared to control participants (interaction p < .05). Mood-induced heroin choice was associated with self-reported heroin use to cope with negative affect ( p < .05), but not social pressure ( p = .39) or cued craving ( p = .52), and with subjective mood reactivity ( p = .007). These data suggest that acute negative mood is a trigger for heroin seeking in heroin-dependent individuals, and this effect is pronounced in those who report using heroin to cope with negative affect, and those who show greater subjective reactivity to negative triggers. Interventions should seek to target negative coping motives to build resilience to affective triggers for relapse.
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Affiliation(s)
- Lee Hogarth
- School of Psychology, University of Exeter, Exeter, United Kingdom
| | - Lorna Hardy
- School of Psychology, University of Exeter, Exeter, United Kingdom
| | - Alexandra Bakou
- School of Psychology, University of Exeter, Exeter, United Kingdom
| | - Justin Mahlberg
- School of Social Sciences and Psychology, Western Sydney University, Sydney, NSW, Australia
| | - Gabrielle Weidemann
- School of Social Sciences and Psychology, Western Sydney University, Sydney, NSW, Australia.,MARCS Institute for Brain, Behaviour and Development, Western Sydney University, Sydney, NSW, Australia
| | - Sharon Cashel
- School of Social Sciences and Psychology, Western Sydney University, Sydney, NSW, Australia
| | - Ahmed A Moustafa
- School of Social Sciences and Psychology, Western Sydney University, Sydney, NSW, Australia.,MARCS Institute for Brain, Behaviour and Development, Western Sydney University, Sydney, NSW, Australia
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