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Li YT, Huang YL, Chen JJJ, Hyland BI, Wickens JR. Phasic dopamine signals are reduced in the spontaneously hypertensive rat and increased by methylphenidate. Eur J Neurosci 2024; 59:1567-1584. [PMID: 38314648 DOI: 10.1111/ejn.16269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2023] [Revised: 12/27/2023] [Accepted: 01/17/2024] [Indexed: 02/06/2024]
Abstract
The spontaneously hypertensive rat (SHR) is a selectively bred animal strain that is frequently used to model attention-deficit hyperactivity disorder (ADHD) because of certain genetically determined behavioural characteristics. To test the hypothesis that the characteristically altered response to positive reinforcement in SHRs may be due to altered phasic dopamine response to reward, we measured phasic dopamine signals in the SHRs and Sprague Dawley (SD) rats using in vivo fast-scan cyclic voltammetry. The effects of the dopamine reuptake inhibitor, methylphenidate, on these signals were also studied. Phasic dopamine signals during the pairing of a sensory cue with electrical stimulation of midbrain dopamine neurons were significantly smaller in the SHRs than in the SD rats. Over repeated pairings, the dopamine response to the sensory cue increased, whereas the response to the electrical stimulation of dopamine neurons decreased, similarly in both strains. However, the final amplitude of the response to the sensory cue after pairing was significantly smaller in SHRs than in the SD rats. Methylphenidate increased responses to sensory cues to a significantly greater extent in the SHRs than in the SD rats, due largely to differences in the low dose effect. At a higher dose, methylphenidate increased responses to sensory cues and electrical stimulation similarly in SHRs and SD rats. The smaller dopamine responses may explain the reduced salience of reward-predicting cues previously reported in the SHR, whereas the action of methylphenidate on the cue response suggests a potential mechanism for the therapeutic effects of low-dose methylphenidate in ADHD.
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Affiliation(s)
- Yu-Ting Li
- Neurobiology Research Unit, Okinawa Institute of Science and Technology, Okinawa, Japan
- Taiwan Instrument Research Institute, National Applied Research Laboratories, Hsinchu, Taiwan
| | - Yi-Ling Huang
- Neurobiology Research Unit, Okinawa Institute of Science and Technology, Okinawa, Japan
| | - Jia-Jin Jason Chen
- Department of Biomedical Engineering, National Cheng Kung University, Tainan, Taiwan
| | - Brian Ian Hyland
- Department of Physiology, Brain Health Research Centre, University of Otago, Dunedin, New Zealand
| | - Jeffery R Wickens
- Neurobiology Research Unit, Okinawa Institute of Science and Technology, Okinawa, Japan
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2
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Söderpalm B, Ericson M. Alcohol and the dopamine system. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2024; 175:21-73. [PMID: 38555117 DOI: 10.1016/bs.irn.2024.02.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/02/2024]
Abstract
The mesolimbic dopamine pathway plays a major role in drug reinforcement and is likely involved also in the development of drug addiction. Ethanol, like most addictive drugs, acutely activates the mesolimbic dopamine system and releases dopamine, and ethanol-associated stimuli also appear to trigger dopamine release. In addition, chronic exposure to ethanol reduces the baseline function of the mesolimbic dopamine system. The molecular mechanisms underlying ethanol´s interaction with this system remain, however, to be unveiled. Here research on the actions of ethanol in the mesolimbic dopamine system, focusing on the involvement of cystein-loop ligand-gated ion channels, opiate receptors, gastric peptides and acetaldehyde is briefly reviewed. In summary, a great complexity as regards ethanol´s mechanism(s) of action along the mesolimbic dopamine system has been revealed. Consequently, several new targets and possibilities for pharmacotherapies for alcohol use disorder have emerged.
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Affiliation(s)
- Bo Söderpalm
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; Department of Addiction and Dependency, Sahlgrenska University Hospital, Gothenburg, Sweden.
| | - Mia Ericson
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
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Allain F, Ehrlich AT, McNicholas M, Gross F, Ma W, Kieffer BL, Darcq E. Chronic tianeptine induces tolerance in analgesia and hyperlocomotion via mu-opioid receptor activation in mice. Front Psychiatry 2023; 14:1186397. [PMID: 37287667 PMCID: PMC10242025 DOI: 10.3389/fpsyt.2023.1186397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Accepted: 04/24/2023] [Indexed: 06/09/2023] Open
Abstract
Introduction Tianeptine is approved in some countries to treat depression and anxiety. In addition to its activity on serotonin and glutamate neurotransmission, tianeptine has been proven to be a mu-opioid receptor (MOR) agonist, but only a few preclinical studies have characterized the opioid-like behavioral effects of tianeptine. Methods In this study, we tested tianeptine activity on G protein activation using the [S35] GTPγS binding assay in brain tissue from MOR+/+ and MOR-/- mice. Then, to determine whether tianeptine behavioral responses are MOR-dependent, we characterized the analgesic, locomotor, and rewarding responses of tianeptine in MOR+/+ and MOR-/- mice using tail immersion, hot plate, locomotor, and conditioned place preference tests. Results Using the [S35] GTPγS binding assay, we found that tianeptine signaling is mediated by MOR in the brain with properties similar to those of DAMGO (a classic MOR agonist). Furthermore, we found that the MOR is necessary for tianeptine's analgesic (tail immersion and hot plate), locomotor, and rewarding (conditioned place preference) effects. Indeed, these behavioral effects could only be measured in MOR+/+ mice but not in MOR-/- mice. Additionally, chronic administration of tianeptine induced tolerance to its analgesic and hyperlocomotor effects. Discussion These findings suggest that tianeptine's opioid-like effects require MOR and that chronic use could lead to tolerance.
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Affiliation(s)
- Florence Allain
- Douglas Hospital Research Center, Department of Psychiatry, McGill University, Montreal, QC, Canada
- Centre de Recherche en Biomédecine de Strasbourg, INSERM, Université de Strasbourg, Strasbourg, France
| | - Aliza T. Ehrlich
- Douglas Hospital Research Center, Department of Psychiatry, McGill University, Montreal, QC, Canada
| | - Michael McNicholas
- Douglas Hospital Research Center, Department of Psychiatry, McGill University, Montreal, QC, Canada
| | - Florence Gross
- Douglas Hospital Research Center, Department of Psychiatry, McGill University, Montreal, QC, Canada
| | - Weiya Ma
- Douglas Hospital Research Center, Department of Psychiatry, McGill University, Montreal, QC, Canada
| | - Brigitte L. Kieffer
- Douglas Hospital Research Center, Department of Psychiatry, McGill University, Montreal, QC, Canada
- Centre de Recherche en Biomédecine de Strasbourg, INSERM, Université de Strasbourg, Strasbourg, France
| | - Emmanuel Darcq
- Douglas Hospital Research Center, Department of Psychiatry, McGill University, Montreal, QC, Canada
- Centre de Recherche en Biomédecine de Strasbourg, INSERM, Université de Strasbourg, Strasbourg, France
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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: 5] [Impact Index Per Article: 2.5] [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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Sustkova-Fiserova M, Charalambous C, Khryakova A, Certilina A, Lapka M, Šlamberová R. The Role of Ghrelin/GHS-R1A Signaling in Nonalcohol Drug Addictions. Int J Mol Sci 2022; 23:761. [PMID: 35054944 PMCID: PMC8776007 DOI: 10.3390/ijms23020761] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 01/05/2022] [Accepted: 01/06/2022] [Indexed: 01/27/2023] Open
Abstract
Drug addiction causes constant serious health, social, and economic burden within the human society. The current drug dependence pharmacotherapies, particularly relapse prevention, remain limited, unsatisfactory, unreliable for opioids and tobacco, and even symptomatic for stimulants and cannabinoids, thus, new more effective treatment strategies are researched. The antagonism of the growth hormone secretagogue receptor type A (GHS-R1A) has been recently proposed as a novel alcohol addiction treatment strategy, and it has been intensively studied in experimental models of other addictive drugs, such as nicotine, stimulants, opioids and cannabinoids. The role of ghrelin signaling in these drugs effects has also been investigated. The present review aims to provide a comprehensive overview of preclinical and clinical studies focused on ghrelin's/GHS-R1A possible involvement in these nonalcohol addictive drugs reinforcing effects and addiction. Although the investigation is still in its early stage, majority of the existing reviewed experimental results from rodents with the addition of few human studies, that searched correlations between the genetic variations of the ghrelin signaling or the ghrelin blood content with the addictive drugs effects, have indicated the importance of the ghrelin's/GHS-R1As involvement in the nonalcohol abused drugs pro-addictive effects. Further research is necessary to elucidate the exact involved mechanisms and to verify the future potential utilization and safety of the GHS-R1A antagonism use for these drug addiction therapies, particularly for reducing the risk of relapse.
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Affiliation(s)
- Magdalena Sustkova-Fiserova
- Department of Pharmacology, Third Faculty of Medicine, Charles University, Ruska 87, 100 00 Prague, Czech Republic; (C.C.); (A.K.); (A.C.); (M.L.)
| | - Chrysostomos Charalambous
- Department of Pharmacology, Third Faculty of Medicine, Charles University, Ruska 87, 100 00 Prague, Czech Republic; (C.C.); (A.K.); (A.C.); (M.L.)
| | - Anna Khryakova
- Department of Pharmacology, Third Faculty of Medicine, Charles University, Ruska 87, 100 00 Prague, Czech Republic; (C.C.); (A.K.); (A.C.); (M.L.)
| | - Alina Certilina
- Department of Pharmacology, Third Faculty of Medicine, Charles University, Ruska 87, 100 00 Prague, Czech Republic; (C.C.); (A.K.); (A.C.); (M.L.)
| | - Marek Lapka
- Department of Pharmacology, Third Faculty of Medicine, Charles University, Ruska 87, 100 00 Prague, Czech Republic; (C.C.); (A.K.); (A.C.); (M.L.)
| | - Romana Šlamberová
- Department of Physiology, Third Faculty of Medicine, Charles University, Ke Karlovu 4, 120 00 Prague, Czech Republic;
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6
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Greenberg D, St. Peter JV. Sugars and Sweet Taste: Addictive or Rewarding? INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph18189791. [PMID: 34574716 PMCID: PMC8468293 DOI: 10.3390/ijerph18189791] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Revised: 09/10/2021] [Accepted: 09/14/2021] [Indexed: 11/16/2022]
Abstract
The notion of food "addiction" often focuses on the overconsumption of sweet tasting foods or so-called sugar "addiction". In the extreme, some have suggested that sugar and sweet tastes elicit neural and behavioral responses analogous to those observed with drugs of abuse. These concepts are complicated by the decades long uncertainty surrounding the validity and reproducibility of functional magnetic resonance imaging (fMRI) methodologies used to characterize neurobiological pathways related to sugar and sweet taste stimuli. There are also questions of whether sweet taste or post-ingestion metabolic consequences of sugar intake would lead to addiction or excessive caloric intake. Here, we present a focused narrative review of literature related to the reward value of sweet taste which suggests that reward value can be confounded with the construct of "addictive potential". Our review seeks to clarify some key distinctions between these constructs and questions the applicability of the addiction construct to human over-eating behaviors. To adequately frame this broad discussion requires the flexibility offered by the narrative review paradigm. We present selected literature on: techniques used to link sugar and sweet tastes to addiction neurobiology and behaviors; sugar and sweet taste "addiction"; the relationship of low calorie sweetener (LCS) intake to addictive behaviors and total calorie intake. Finally, we examined the reward value of sweet tastes and contrasted that with the literature describing addiction. The lack of reproducibility of fMRI data remains problematic for attributing a common neurobiological pathway activation of drugs and foods as conclusive evidence for sugar or sweet taste "addiction". Moreover, the complicated hedonics of sweet taste and reward value are suggested by validated population-level data which demonstrate that the consumption of sweet taste in the absence of calories does not increase total caloric intake. We believe the neurobiologies of reward value and addiction to be distinct and disagree with application of the addiction model to sweet food overconsumption. Most hypotheses of sugar "addiction" attribute the hedonics of sweet foods as the equivalent of "addiction". Further, when addictive behaviors and biology are critically examined in totality, they contrast dramatically from those associated with the desire for sweet taste. Finally, the evidence is strong that responses to the palatability of sweets rather than their metabolic consequences are the salient features for reward value. Thus, given the complexity of the controls of food intake in humans, we question the usefulness of the "addiction" model in dissecting the causes and effects of sweet food over-consumption.
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Affiliation(s)
- Danielle Greenberg
- NutriSci Inc., Mt. Kisco, NY 10549, USA
- Correspondence: ; Tel.: +1-(914)572-2972
| | - John V. St. Peter
- Deptartment of Experimental & Clinical Pharmacology, University of Minnesota, Minneapolis, MN 55455, USA;
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Gordon-Fennell A, Stuber GD. Illuminating subcortical GABAergic and glutamatergic circuits for reward and aversion. Neuropharmacology 2021; 198:108725. [PMID: 34375625 DOI: 10.1016/j.neuropharm.2021.108725] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 07/13/2021] [Accepted: 07/15/2021] [Indexed: 02/07/2023]
Abstract
Reinforcement, reward, and aversion are fundamental processes for guiding appropriate behaviors. Longstanding theories have pointed to dopaminergic neurons of the ventral tegmental area (VTA) and the limbic systems' descending pathways as crucial systems for modulating these behaviors. The application of optogenetic techniques in neurotransmitter- and projection-specific circuits has supported and enhanced many preexisting theories but has also revealed many unexpected results. Here, we review the past decade of optogenetic experiments to study the neural circuitry of reinforcement and reward/aversion with a focus on the mesolimbic dopamine system and brain areas along the medial forebrain bundle (MFB). The cumulation of these studies to date has revealed generalizable findings across molecularly defined cell types in areas of the basal forebrain and anterior hypothalamus. Optogenetic stimulation of GABAergic neurons in these brain regions drives reward and can support positive reinforcement and optogenetic stimulation of glutamatergic neurons in these regions drives aversion. We also review studies of the activity dynamics of neurotransmitter defined populations in these areas which have revealed varied response patterns associated with motivated behaviors.
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Affiliation(s)
- Adam Gordon-Fennell
- Center for the Neurobiology of Addiction, Pain, and Emotion, Department of Anesthesiology and Pain Medicine, Department of Pharmacology, University of Washington, 98195, Seattle, WA, USA
| | - Garret D Stuber
- Center for the Neurobiology of Addiction, Pain, and Emotion, Department of Anesthesiology and Pain Medicine, Department of Pharmacology, University of Washington, 98195, Seattle, WA, USA.
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8
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Nieto SJ, Baskerville W, Donato S, Bujarski S, Ray L. Lifetime heavy drinking years predict alcohol use disorder severity over and above current alcohol use. THE AMERICAN JOURNAL OF DRUG AND ALCOHOL ABUSE 2021; 47:630-637. [PMID: 34134588 DOI: 10.1080/00952990.2021.1938100] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Background: Preclinical studies demonstrate that chronic and heavy alcohol use facilitates neuroadaptations that perpetuate addiction-like behaviors. In clinical studies, it is unclear whether the extent of heavy alcohol use over the lifetime contributes to alcohol use disorder (AUD) severity over and above current alcohol use patterns (i.e. last 30 days to 3-months). Such information may improve our understanding of the phenomenology of AUD.Objectives: The purpose of this study was to examine lifetime heavy drinking years in relation to a clinical assessment of AUD.Methods: Participants, who were non-treatment-seeking and engaged in heavy drinking (n = 140; 50% male), completed an interview-based assessment of lifetime regular and heavy drinking years along with a battery of measures indexing alcohol use and problems, drinking motives, and depression and anxiety symptomatology.Results: Lifetime heavy drinking years was positively associated with lifetime regular drinking years, current alcohol use, alcohol problems, tonic alcohol craving, drinking for the enhancing effects of alcohol, and drinking to cope (r's = .21-.58). Adjusting for lifetime regular drinking years and current alcohol use, lifetime heavy drinking years predicted higher scores on the Alcohol Use Disorder Identification Test (AUDIT; B = .382; SE = .123). A multivariate logistic regression found that lifetime heavy drinking years predicted greater odds of more severe AUD over and above current alcohol use (OR = 1.147).Conclusion: Our findings suggest that lifetime heavy drinking years are a clinically meaningful indicator of AUD severity that is not redundant with current alcohol use measures.
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Affiliation(s)
- Steven J Nieto
- Department of Psychology, University of California Los Angeles, Los Angeles, CA, USA
| | - Wave Baskerville
- Department of Psychology, University of California Los Angeles, Los Angeles, CA, USA
| | - Suzanna Donato
- 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
| | - Lara Ray
- Department of Psychology, University of California Los Angeles, Los Angeles, CA, USA.,Department of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles, Los Angeles, CA, USA.,Brain Research Institute, University of California Los Angeles, Los Angeles, CA, USA
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9
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Epstein LH, O'Donnell S, Biondolillo MJ, Hostler D, Roemmich JN. Comparing the reinforcing value of high intensity interval training versus moderate intensity aerobic exercise in sedentary adults. Physiol Behav 2021; 238:113468. [PMID: 34033846 DOI: 10.1016/j.physbeh.2021.113468] [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: 04/26/2021] [Revised: 05/18/2021] [Accepted: 05/19/2021] [Indexed: 10/21/2022]
Abstract
Exercise is a reinforcer for both animals and humans, as they will work progressively harder to gain access for the opportunity to exercise. Exercise activates brain reward pathways similar to drugs of abuse, and the magnitude of the reinforcing value of exercise is a predictor of exercise behavior. The majority of research on exercise reinforcement has studied moderate intensity aerobic exercise (MIAE) or resistance training. There is limited research on the relative reinforcing value (RRV) of high intensity interval training (HIIT), which is often reported to be a preferred form of exercise in comparison to MIAE. Experiment 1 was a pilot study of 20 sedentary females designed to compare the reliability of differences in RRVHIIT vs RRVMIAE over two sessions, assess protocols comparing different volumes of HIIT in comparison to MIAE, and estimate sample sizes needed for a fully powered study to assess which type of exercise protocol was a better substitute for a highly liked sedentary activity. Experiment 2 studied 44 participants to assess whether HIIT or MIAE would be better substitutes for highly liked sedentary activities. Experiment 1 showed that measures of RRVHIIT or RRVMIAE were reliable, and that volume of HIIT did not influence RRVHIIT, even if it was of equal amount or duration to MIAE. Experiment 2 showed that HIIT was a more preferred substitute for sedentary behaviors than MIAE. Predictors of RRVMIAE were liking of MIAE and pleasantness of affect post MIAE. These results suggest inactive people may find interval training to be more reinforcing than MIAE, and may be more likely to adopt and maintain an exercise program involving HIIT rather than MIAE. The next stage of research should be to understand how to sensitize the RRV of exercise to motivate sedentary people to be more active.
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Affiliation(s)
- Leonard H Epstein
- Department of Pediatrics, University at Buffalo Jacobs School of Medicine and Biomedical Sciences, Buffalo, New York.
| | - Sara O'Donnell
- Department of Pediatrics, University at Buffalo Jacobs School of Medicine and Biomedical Sciences, Buffalo, New York
| | - Mathew J Biondolillo
- Department of Pediatrics, University at Buffalo Jacobs School of Medicine and Biomedical Sciences, Buffalo, New York
| | - David Hostler
- Department of Exercise and Nutrition Sciences, University at Buffalo School of Public Health and Health Sciences, Buffalo, New York
| | - James N Roemmich
- Grand Forks Human Nutrition Research Center, USDA Agricultural Research Service, Grand Forks, North Dakota
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Edvardsson CE, Vestlund J, Jerlhag E. A ghrelin receptor antagonist reduces the ability of ghrelin, alcohol or amphetamine to induce a dopamine release in the ventral tegmental area and in nucleus accumbens shell in rats. Eur J Pharmacol 2021; 899:174039. [PMID: 33737011 DOI: 10.1016/j.ejphar.2021.174039] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 03/10/2021] [Accepted: 03/11/2021] [Indexed: 11/24/2022]
Abstract
The orexigenic peptide ghrelin increases the release of dopamine in the nucleus accumbens (NAc) shell via central ghrelin receptors, especially those located in the ventral tegmental area (VTA). The activity of the VTA dopamine neurons projecting to NAc shell, involves somatodendritic dopamine release within the VTA. However, the effects of ghrelin on the concomitant dopamine release in the VTA and NAc shell is unknown. It is further unknown whether addictive drugs, such as alcohol and amphetamine, enhance the dopamine levels in both these areas via ghrelin receptor dependent mechanisms. Thus, the effects of a ghrelin receptor antagonist, JMV2959, on the ability of i) central ghrelin ii) systemic alcohol or iii) systemic amphetamine to increase the dopamine release in the VTA and in the NAc shell in rats by using in vivo microdialysis was explored. We showed that systemic administration of JMV2959 blocks the ability of central ghrelin to increases dopamine release in the VTA and the NAc shell, and reduces the alcohol- and amphetamine-induced dopamine release in both these areas. Locomotor activity studies was then conducted in an attempt to correlate the ghrelin-induced dopamine release in the VTA to a behavioural outcome. These revealed that local infusion of a dopamine D1 receptor antagonist into the VTA blocks the ability of central ghrelin to cause a locomotor stimulation in mice. Collectively, this study adds to the growing body of evidence indicating that ghrelin signalling modulates the ability of ghrelin, and addictive drugs, to activate the mesoaccumbal dopamine pathway.
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Affiliation(s)
- Christian E Edvardsson
- Institute of Neuroscience and Physiology, Department of Pharmacology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Jesper Vestlund
- Institute of Neuroscience and Physiology, Department of Pharmacology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Elisabet Jerlhag
- Institute of Neuroscience and Physiology, Department of Pharmacology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden.
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11
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Grover T, Gupta R, Arora G, Bal CS, Ambekar A, Basu Ray S, Vaswani M, Sharma A. Dopamine transporter availability in alcohol and opioid dependent subjects - a 99mTc-TRODAT-1SPECT imaging and genetic association study. Psychiatry Res Neuroimaging 2020; 305:111187. [PMID: 32947183 DOI: 10.1016/j.pscychresns.2020.111187] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Revised: 09/05/2020] [Accepted: 09/08/2020] [Indexed: 11/24/2022]
Abstract
Drug dependence associated with increased dopamine neurotransmission and neuroplastic changes is influenced by Dopamine transporters (DAT) which are modulated by genetic and epigenetic factors. This study assesses DAT availability in relation to the 40bp DAT1 VNTR (genetic) and DAT1 promoter methylation (epigenetic) changes in patients with alcohol dependence (AD) and opioid dependence (OD). A total of 60 subjects (n=20 each of AD, OD and controls) were recruited. SPECT/CT imaging using 99mTc-TRODAT-1 was performed for measuring striatal DAT availability and DNA screened to check DAT1promoter methylation and 40bp VNTR polymorphism. SPECT/CT imaging revealed significant decrease in DAT availability in the striatum and putamen and significant increase in DAT1 promoter methylation in AD compared to control and OD. The 40bp VNTR distribution was similar in all three groups with 10repeat and 9repeat alleles being the most common. The AD individuals with DAT1promoter methylation showed significantly lower TRODAT-1 uptake compared to the ones with no methylation. AD individuals homozygous for the 10repeat VNTR also showed reduced DAT availability. This is the first imaging study using 99mTc-TRODAT-1 from India documenting significantly reduced striatal DAT availability, increased DAT methylation and frequency of 10repeat individuals associated with decreased DAT availability in AD.
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Affiliation(s)
- Tripti Grover
- Laboratory of Cyto-Molecular Genetics, Department of Anatomy, AIIMS, New Delhi 110029, India
| | - Ranjan Gupta
- Laboratory of Cyto-Molecular Genetics, Department of Anatomy, AIIMS, New Delhi 110029, India
| | | | | | - Atul Ambekar
- National Drug Dependence Treatment Center, Department of Psychiatry, AIIMS, New Delhi 110029, India
| | - Subrata Basu Ray
- Laboratory of Cyto-Molecular Genetics, Department of Anatomy, AIIMS, New Delhi 110029, India
| | - Meera Vaswani
- National Drug Dependence Treatment Center, Department of Psychiatry, AIIMS, New Delhi 110029, India; University of Minnesota, USA
| | - Arundhati Sharma
- Laboratory of Cyto-Molecular Genetics, Department of Anatomy, AIIMS, New Delhi 110029, India.
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Moose JE, Leets KA, Mate NA, Chisholm JD, Hougland JL. An overview of ghrelin O-acyltransferase inhibitors: a literature and patent review for 2010-2019. Expert Opin Ther Pat 2020; 30:581-593. [PMID: 32564644 DOI: 10.1080/13543776.2020.1776263] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
INTRODUCTION The peptide hormone ghrelin regulates physiological processes associated with energy homeostasis such as appetite, insulin signaling, glucose metabolism, and adiposity. Ghrelin has also been implicated in a growing number of neurological pathways involved in stress response and addiction behavior. For ghrelin to bind the growth hormone secretagogue receptor 1a (GHS-R1a) and activate signaling, the hormone must first be octanoylated on a specific serine side chain. This key transformation is performed by the enzyme ghrelin O-acyltransferase (GOAT), and therefore GOAT inhibitors may be useful in treating disorders related to ghrelin signaling such as diabetes, obesity, and related metabolic syndromes. AREAS COVERED This report covers ghrelin and GOAT as potential therapeutic targets and summarizes work on GOAT inhibitors through the end of 2019, highlighting recent successes with both peptidomimetics and small molecule GOAT inhibitors as potent modulators of GOAT-catalyzed ghrelin octanoylation. EXPERT OPINION A growing body of biochemical and structural knowledge regarding the ghrelin/GOAT system now enables multiple avenues for identifying and optimizing GOAT inhibitors. We are at the beginning of a new era with increased opportunities for leveraging ghrelin and GOAT in the understanding and treatment of multiple health conditions including diabetes, obesity, and addiction.
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Affiliation(s)
- Jacob E Moose
- Department of Chemistry and BioInspired Syracuse, Syracuse University , Syracuse, NY, USA
| | - Katelyn A Leets
- Department of Chemistry and BioInspired Syracuse, Syracuse University , Syracuse, NY, USA
| | - Nilamber A Mate
- Department of Chemistry and BioInspired Syracuse, Syracuse University , Syracuse, NY, USA
| | - John D Chisholm
- Department of Chemistry and BioInspired Syracuse, Syracuse University , Syracuse, NY, USA
| | - James L Hougland
- Department of Chemistry and BioInspired Syracuse, Syracuse University , Syracuse, NY, USA
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13
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Carr KD. Homeostatic regulation of reward via synaptic insertion of calcium-permeable AMPA receptors in nucleus accumbens. Physiol Behav 2020; 219:112850. [PMID: 32092445 PMCID: PMC7108974 DOI: 10.1016/j.physbeh.2020.112850] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 01/23/2020] [Accepted: 02/18/2020] [Indexed: 10/25/2022]
Abstract
The incentive effects of food and related cues are determined by stimulus properties and the internal state of the organism. Enhanced hedonic reactivity and incentive motivation in energy deficient subjects have been demonstrated in animal models and humans. Defining the neurobiological underpinnings of these state-based modulatory effects could illuminate fundamental mechanisms of adaptive behavior, as well as provide insight into maladaptive consequences of weight loss dieting and the relationship between disturbed eating behavior and substance abuse. This article summarizes research of our laboratory aimed at identifying neuroadaptations induced by chronic food restriction (FR) that increase the reward magnitude of drugs and associated cues. The main findings are that FR decreases basal dopamine (DA) transmission, upregulates signaling downstream of the D1 DA receptor (D1R), and triggers synaptic incorporation of calcium-permeable AMPA receptors (CP-AMPARs) in the nucleus accumbens (NAc). Selective antagonism of CP-AMPARs decreases excitatory postsynaptic currents in NAc medium spiny neurons of FR rats and blocks the enhanced rewarding effects of d-amphetamine and a D1R, but not a D2R, agonist. These results suggest that FR drives CP-AMPARs into the synaptic membrane of D1R-expressing MSNs, possibly as a homeostatic response to reward loss. FR subjects also display diminished aversion for contexts associated with LiCl treatment and centrally infused cocaine. An encompassing, though speculative, hypothesis is that NAc synaptic incorporation of CP-AMPARs in response to food scarcity and other forms of sustained reward loss adaptively increases incentive effects of reward stimuli and, at the same time, diminishes responsiveness to aversive stimuli that have potential to interfere with goal pursuit.
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Affiliation(s)
- Kenneth D Carr
- Departments of Psychiatry and Biochemistry and Molecular Pharmacology, New York University School of Medicine, 435 East 30th Street, New York, NY 10016, United States.
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14
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Grodin EN, Bujarski S, Venegas A, Baskerville WA, Nieto SJ, Jentsch JD, Ray LA. Reward, Relief and Habit Drinking: Initial Validation of a Brief Assessment Tool. Alcohol Alcohol 2020; 54:574-583. [PMID: 31557278 DOI: 10.1093/alcalc/agz075] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 08/13/2019] [Accepted: 08/14/2019] [Indexed: 12/21/2022] Open
Abstract
AIMS Alcohol use disorder is highly heterogeneous. One approach to understanding this heterogeneity is the identification of drinker subtypes. A candidate classification consists of reward and relief subtypes. The current study examines a novel self-report measure of reward, relief, and habit drinking for its clinical correlates and subjective response (SR) to alcohol administration. METHODS Non-treatment-seeking heavy drinkers (n = 140) completed the brief reward, relief, habit drinking scale (RRHDS). A subset of this sample (n = 67) completed an intravenous alcohol administration. Individuals were classified into drinker subtypes. A crowdsourced sample of heavy drinkers (n = 187) completed the RRHDS and a validated reward relief drinking scale to compare drinking classification results. RESULTS The majority of the sample was classified as reward drinkers (n = 100), with fewer classified as relief (n = 19) and habit (n = 21) drinkers. Relief and habit drinkers reported greater tonic alcohol craving compared to reward drinkers. Reward drinkers endorsed drinking for enhancement, while relief drinkers endorsed drinking for coping. Regarding the alcohol administration, the groups differed in negative mood, such that relief/habit drinkers reported a decrease in negative mood during alcohol administration, compared to reward drinkers. The follow-up crowdsourcing study found a 62% agreement in reward drinker classification between measures and replicated the tonic craving findings. CONCLUSIONS Our findings suggest that reward drinkers are dissociable from relief/habit drinkers using the brief measure. However, relief and habit drinkers were not successfully differentiated, which suggests that these constructs may overlap phenotypically. Notably, measures of dysphoric mood were better at detecting group differences than measures capturing alcohol's rewarding effects.
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Affiliation(s)
- Erica N Grodin
- Department of Psychology, University of California 1285 Franz Hall, Box 951563 Los Angeles, CA 90095.,Department of Psychiatry and Biobehavioral Sciences University of California 760 Westwood Plaza Los Angeles, CA 90095
| | - Spencer Bujarski
- Department of Psychology, University of California 1285 Franz Hall, Box 951563 Los Angeles, CA 90095
| | - Alexandra Venegas
- Department of Psychology, University of California 1285 Franz Hall, Box 951563 Los Angeles, CA 90095
| | - Wave-Ananda Baskerville
- Department of Psychology, University of California 1285 Franz Hall, Box 951563 Los Angeles, CA 90095
| | - Steven J Nieto
- Department of Psychology, University of California 1285 Franz Hall, Box 951563 Los Angeles, CA 90095
| | - J David Jentsch
- Department of Psychology Binghamton University State University of New York PO Box 6000 Binghamton NY 13902
| | - Lara A Ray
- Department of Psychology, University of California 1285 Franz Hall, Box 951563 Los Angeles, CA 90095.,Department of Psychiatry and Biobehavioral Sciences University of California 760 Westwood Plaza Los Angeles, CA 90095
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15
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Junghanns K, Backhaus J, Tietz U, Lange W, Rink L, Wetterling T, Driessen M. The consumption of cigarettes, coffee and sweets in detoxified alcoholics and its association with relapse and a family history of alcoholism. Eur Psychiatry 2020; 20:451-5. [PMID: 16171658 DOI: 10.1016/j.eurpsy.2004.09.011] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2003] [Revised: 06/14/2004] [Accepted: 08/25/2004] [Indexed: 10/26/2022] Open
Abstract
AbstractThirty male alcohol dependent inpatients without concurrent depressive disorder, 13 of them with a positive family history of alcohol dependence in a first degree relative (PFH), were questioned about their desire and consumption habits with respect to cigarettes, coffee, and sweets while on a three-week inpatient treatment after detoxification from alcohol. Six weeks after discharge from hospital, the patients were reassessed for relapse. Eleven patients (36.6%) had relapsed at follow-up. Relapsers were younger than abstainers. The days until relapse correlated negatively with intensity of desire to drink alcohol, desire to smoke cigarettes, and with a higher consumption of cigarettes. PFH patients did not relapse earlier but they had a stronger desire to drink coffee and eat sweets and had a higher coffee consumption.
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Affiliation(s)
- Klaus Junghanns
- Department of Psychiatry and Psychotherapy, University of Luebeck, Ratzeburger Allee 160, D-23538 Luebeck, Germany.
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16
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Boecker L, Pauli P. Affective startle modulation and psychopathology: Implications for appetitive and defensive brain systems. Neurosci Biobehav Rev 2019; 103:230-266. [PMID: 31129237 DOI: 10.1016/j.neubiorev.2019.05.019] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Revised: 05/12/2019] [Accepted: 05/18/2019] [Indexed: 02/06/2023]
Abstract
Startle reflex potentiation versus startle attenuation to unpleasant versus pleasant stimuli likely reflect priming of the defensive versus appetitive motivational systems, respectively. This review summarizes and systemizes the literature on affective startle modulation related to psychopathologies with the aim to reveal underlying mechanisms across psychopathologies. We found evidence for psychopathologies characterized by increased startle potentiation to unpleasant stimuli (anxiety disorders), decreased startle potentiation to unpleasant stimuli (psychopathy), decreased startle attenuation to pleasant stimuli (ADHD), as well as a general hyporeactivity to affective stimuli (depression). Increased versus decreased startle responses to disorder-specific stimuli characterize specific phobia and drug dependence. No psychopathology is characterized by increased startle attenuation to standard pleasant stimuli or a general hyperreactivity to affective stimuli. This review indicates that the defensive and the appetitive systems operate independently mostly in accordance with the motivational priming hypothesis and that affective startle modulation is a highly valuable paradigm to unraveling dysfunctions of the defensive and appetitive systems in psychopathologies as requested by the Research Domain Criteria initiative.
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Affiliation(s)
- Lea Boecker
- Department of Economic Psychology, Social Psychology & Experimental Methods, Leuphana University of Lüneburg, Universitätsallee 1, 21335 Lüneburg, Germany.
| | - Paul Pauli
- Department of Psychology (Biological Psychology, Clinical Psychology, and Psychotherapy), University of Würzburg, Marcusstraße 9-11, 97070 Germany; Center of Mental Health, Medical Faculty, University of Würzburg, Germany
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17
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Burchi E, Makris N, Lee MR, Pallanti S, Hollander E. Compulsivity in Alcohol Use Disorder and Obsessive Compulsive Disorder: Implications for Neuromodulation. Front Behav Neurosci 2019; 13:70. [PMID: 31139059 PMCID: PMC6470293 DOI: 10.3389/fnbeh.2019.00070] [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] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 03/22/2019] [Indexed: 01/22/2023] Open
Abstract
Alcohol use Disorder (AUD) is one of the leading causes of morbidity and mortality worldwide. The progression of the disorder is associated with the development of compulsive alcohol use, which in turn contributes to the high relapse rate and poor longer term functioning reported in most patients, even with treatment. While the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) defines AUD by a cluster of symptoms, parsing its heterogeneous phenotype by domains of behavior such as compulsivity may be a critical step to improve outcomes of this condition. Still, neurobiological underpinnings of compulsivity need to be fully elucidated in AUD in order to better design targeted treatment strategies. In this manuscript, we review and discuss findings supporting common mechanisms between AUD and OCD, dissecting the construct of compulsivity and focusing specifically on characteristic disruptions in habit learning and cognitive control in the two disorders. Finally, neuromodulatory interventions are proposed as a probe to test compulsivity as key pathophysiologic feature of AUD, and as a potential therapy for the subgroup of individuals with compulsive alcohol use, i.e., the more resistant stage of the disorder. This transdiagnostic approach may help to destigmatize the disorder, and suggest potential treatment targets across different conditions.
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Affiliation(s)
- Elisabetta Burchi
- Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, NY, United States.,Department of Health Sciences, University of Florence, Florence, Italy
| | - Nikolaos Makris
- Center for Morphometric Analysis, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States.,Psychiatry Neuroimaging Laboratory, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States
| | - Mary R Lee
- Section on Clinical Psychoneuroendocrinology and Neuropsychopharmacology, National Institute on Alcohol Abuse and Alcoholism and National Institute on Drug Abuse, Bethesda, MD, United States
| | - Stefano Pallanti
- Department of Psychiatry and Behavioral Sciences, Stanford University Medical Center, Stanford, CA, United States
| | - Eric Hollander
- Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, NY, United States
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18
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Stanford SC, Heal DJ. Catecholamines: Knowledge and understanding in the 1960s, now, and in the future. Brain Neurosci Adv 2019; 3:2398212818810682. [PMID: 32166174 PMCID: PMC7058270 DOI: 10.1177/2398212818810682] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Indexed: 11/16/2022] Open
Abstract
The late 1960s was a heyday for catecholamine research. Technological developments made it feasible to study the regulation of sympathetic neuronal transmission and to map the distribution of noradrenaline and dopamine in the brain. At last, it was possible to explain the mechanism of action of some important drugs that had been used in the clinic for more than a decade (e.g. the first generation of antidepressants) and to contemplate the rational development of new treatments (e.g. l-dihydroxyphenylalanine therapy, to compensate for the dopaminergic neuropathy in Parkinson’s disease, and β1-adrenoceptor antagonists as antihypertensives). The fact that drug targeting noradrenergic and/or dopaminergic transmission are still the first-line treatments for many psychiatric disorders (e.g. depression, schizophrenia, and attention deficit hyperactivity disorder) is a testament to the importance of these neurotransmitters and the research that has helped us to understand the regulation of their function. This article celebrates some of the highlights of research at that time, pays tribute to some of the subsequent landmark studies, and appraises the options for where it could go next.
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Affiliation(s)
- S Clare Stanford
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
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19
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Jerlhag E. Gut-brain axis and addictive disorders: A review with focus on alcohol and drugs of abuse. Pharmacol Ther 2018; 196:1-14. [PMID: 30439457 DOI: 10.1016/j.pharmthera.2018.11.005] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Due to the limited efficacy of existing medications for addictive disorders including alcohol use disorder (AUD), the need for additional medications is substantial. Potential new medications for addiction can be identified through investigation of the neurochemical substrates mediating the ability of drugs of abuse such as alcohol to activate the mesolimbic dopamine system. Interestingly, recent studies implicate neuropeptides of the gut-brain axis as modulators of reward and addiction processes. The present review therefore summarizes the current studies investigating the ability of the gut-brain peptides ghrelin, glucagon-like peptide-1 (GLP-1), amylin and neuromedin U (NMU) to modulate alcohol- and drug-related behaviors in rodents and humans. Extensive literature demonstrates that ghrelin, the only known orexigenic neuropeptide to date, enhances reward as well as the intake of alcohol, and other drugs of abuse, while ghrelin receptor antagonism has the opposite effects. On the other hand, the anorexigenic peptides GLP-1, amylin and NMU independently inhibits reward from alcohol and drugs of abuse in rodents. Collectively, these rodent and human studies imply that central ghrelin, GLP-1, amylin and NMU signaling may contribute to addiction processes. Therefore, the need for randomized clinical trials investigating the effects of agents targeting these aforementioned systems on drug/alcohol use is substantial.
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Affiliation(s)
- Elisabet Jerlhag
- Institute of Neuroscience and Physiology, Department of Pharmacology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden.
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20
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Role of glutamatergic system and mesocorticolimbic circuits in alcohol dependence. Prog Neurobiol 2018; 171:32-49. [PMID: 30316901 DOI: 10.1016/j.pneurobio.2018.10.001] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 09/08/2018] [Accepted: 10/08/2018] [Indexed: 02/06/2023]
Abstract
Emerging evidence demonstrates that alcohol dependence is associated with dysregulation of several neurotransmitters. Alterations in dopamine, glutamate and gamma-aminobutyric acid release are linked to chronic alcohol exposure. The effects of alcohol on the glutamatergic system in the mesocorticolimbic areas have been investigated extensively. Several studies have demonstrated dysregulation in the glutamatergic systems in animal models exposed to alcohol. Alcohol exposure can lead to an increase in extracellular glutamate concentrations in mesocorticolimbic brain regions. In addition, alcohol exposure affects the expression and functions of several glutamate receptors and glutamate transporters in these brain regions. In this review, we discussed the effects of alcohol exposure on glutamate receptors, glutamate transporters and glutamate homeostasis in each area of the mesocorticolimbic system. In addition, we discussed the genetic aspect of alcohol associated with glutamate and reward circuitry. We also discussed the potential therapeutic role of glutamate receptors and glutamate transporters in each brain region for the treatment of alcohol dependence. Finally, we provided some limitations on targeting the glutamatergic system for potential therapeutic options for the treatment alcohol use disorders.
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21
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Abstract
Drug addiction or substance-use disorder is a chronically relapsing disorder that progresses through binge/intoxication, withdrawal/negative affect and preoccupation/anticipation stages. These stages represent diverse neurobiological mechanisms that are differentially involved in the transition from recreational to compulsive drug use and from positive to negative reinforcement. The progression from recreational to compulsive substance use is associated with downregulation of the brain reward systems and upregulation of the brain stress systems. Individual differences in the neurobiological systems that underlie the processing of reward, incentive salience, habits, stress, pain, and executive function may explain (i) the vulnerability to substance-use disorder; (ii) the diversity of emotional, motivational, and cognitive profiles of individuals with substance-use disorders; and (iii) heterogeneous responses to cognitive and pharmacological treatments. Characterization of the neuropsychological mechanisms that underlie individual differences in addiction-like behaviors is the key to understanding the mechanisms of addiction and development of personalized pharmacotherapy.
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Affiliation(s)
- Olivier George
- Department of Neuroscience, The Scripps Research Institute, La Jolla, California, USA
| | - George F Koob
- National Institute on Alcohol Abuse and Alcoholism, Rockville, Maryland, USA
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22
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Even-Chen O, Barak S. The role of fibroblast growth factor 2 in drug addiction. Eur J Neurosci 2018; 50:2552-2561. [PMID: 30144335 DOI: 10.1111/ejn.14133] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 08/08/2018] [Accepted: 08/16/2018] [Indexed: 12/21/2022]
Abstract
Fibroblast growth factor 2 (FGF2) is a member of the FGF-family, which consists of 22 members, with four known FGF receptors (five in humans). Over the last 30 years, FGF2 has been extensively studied for its role in cell proliferation, differentiation, growth, survival and angiogenesis during development, as well as for its role in adult neurogenesis and regenerative plasticity. Over the past decade, FGF2 has been implicated in learning and memory, as well as in several neuropsychiatric disorders, including anxiety, stress, depression and drug addiction. In this review, we present accumulating evidence indicating the involvement of FGF2 in neuroadaptations caused by drugs of abuse, namely, amphetamine, cocaine, nicotine and alcohol. Moreover, evidence suggests that FGF2 is a positive regulator of alcohol and drug-related behaviors. Thus, although additional studies are yet required, we suggest that reducing FGF2 activity may provide a novel therapeutic approach for substance use disorders.
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Affiliation(s)
- Oren Even-Chen
- School of Psychological Sciences, Tel Aviv University, 69978, Tel Aviv, Israel
| | - Segev Barak
- School of Psychological Sciences, Tel Aviv University, 69978, Tel Aviv, Israel.,Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
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23
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Hogg DW, Chen Y, D'Aquila AL, Xu M, Husić M, Tan LA, Bull C, Lovejoy DA. A novel role of the corticotrophin-releasing hormone regulating peptide, teneurin C-terminal associated peptide 1, on glucose uptake into the brain. J Neuroendocrinol 2018; 30:e12579. [PMID: 29411913 DOI: 10.1111/jne.12579] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Revised: 01/11/2018] [Accepted: 01/31/2018] [Indexed: 02/06/2023]
Abstract
Teneurin C-terminal associated peptide (TCAP) is an ancient paracrine signalling agent that evolved via lateral gene transfer from prokaryotes into an early metazoan ancestor. Although it bears structural similarity to corticotrophin-releasing hormone (CRH), it inhibits the in vivo actions of CRH. The TCAPs are highly expressed in neurones, where they induce rapid cytoskeletal rearrangement and are neuroprotective. Because these processes are highly energy-dependent, this suggests that TCAP has the potential to regulate glucose uptake because glucose is the primary energy substrate in brain, and neurones require a steady supply to meet the high metabolic demands of neuronal communication. Therefore, the objective of the present study was to assess the effect of TCAP-mediated glucose uptake in the brain and in neuronal cell models. TCAP-mediated 18 F-deoxyglucose (FDG) uptake into brain tissue was assessed in male wild-type Wistar rats by functional positron emission tomography. TCAP-1 increased FDG uptake by over 40% into cortical regions of the brain, demonstrating that TCAP-1 can significantly enhance glucose supply. Importantly, a single nanomolar injection of TCAP-1 increased brain glucose after 3 days and decreased blood glucose after 1 week. This is corroborated by a decreased serum concentration of insulin and an increased serum concentration of glucagon. In immortalised hypothalamic neurones, TCAP-1 increased ATP production and enhanced glucose uptake by increasing glucose transporter recruitment to the plasma membrane likely via AKT and mitogen-activated protein kinase/ERK phosphorylation events. Taken together, these data demonstrate that TCAP-1 increases glucose metabolism in neurones, and may represent a peptide signalling agent that regulated glucose uptake before insulin and related peptides.
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Affiliation(s)
- D W Hogg
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
| | - Y Chen
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
| | - A L D'Aquila
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
| | - M Xu
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
| | - M Husić
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
| | - L A Tan
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
| | - C Bull
- Molecular Imaging Inc., Ann Arbor, MI, USA
| | - D A Lovejoy
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
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24
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Demontis F, Serra F, Serra G. Antidepressant-induced Dopamine Receptor Dysregulation: A Valid Animal Model of Manic-Depressive Illness. Curr Neuropharmacol 2018; 15:417-423. [PMID: 28503114 PMCID: PMC5405612 DOI: 10.2174/1570159x14666160715165648] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2016] [Revised: 03/05/2016] [Accepted: 05/24/2016] [Indexed: 11/22/2022] Open
Abstract
Background: Mania seems to be associated with an increased dopamine (DA) transmission. Antidepressant treatments can induce mania in humans and potentiated DA transmission in animals, by sensitizing DA D2 receptors in the mesolimbic system. We have suggested that the sensitization of D2 receptors may be responsible of antidepressant-induced mania. This review aims to report the experimental evidence that led to the hypothesis that antidepressant-induced DA receptors dysregulation can be considered an animal model of bipolar disorder. Methods: We reviewed papers reporting preclinical and clinical studies on the role of DA in the mechanism of action of antidepressant treatments and in the patho-physiology of mood disorders. Results: A number of preclinical and clinical evidence suggests that mania could be associated with an increased DA activity, while a reduced function of this neurotransmission might underlie depression. Chronic treatment with imipramine induces a sensitization of DA D2 receptors in the mesolimbic system, followed, after drug discontinuation, by a reduced sensitivity associated with an increased immobility time in forced swimming test of depression (FST). Blockade of glutamate NMDA receptors by memantine administration prevents the imipramine effect on DA receptors sensitivity and on the FST. Conclusion: We suggest that chronic treatment with antidepressants induces a behavioural syndrome that mimics mania (the sensitization of DA receptors), followed by depression (desensitization of DA receptors and increased immobility time in the FST), i.e. an animal model of bipolar disorder. Moreover the observation that memantine prevents the “bipolar-like” behavior, suggests that the drug may have an antimanic and mood stabilizing effect. Preliminary clinical observations support this hypothesis.
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Affiliation(s)
- Francesca Demontis
- Department of Biomedical Sciences, University of Sassari, 07100 Sassari, Italy
| | - Francesca Serra
- Department of General Psychology, University of Padua, Italy
| | - Gino Serra
- Department of Biomedical Sciences, University of Sassari, 07100 Sassari, Italy
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25
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Jerlhag E. GLP-1 signaling and alcohol-mediated behaviors; preclinical and clinical evidence. Neuropharmacology 2018; 136:343-349. [PMID: 29337226 DOI: 10.1016/j.neuropharm.2018.01.013] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 12/18/2017] [Accepted: 01/09/2018] [Indexed: 12/20/2022]
Abstract
Alcohol addiction, affecting approximately four percent of the population, contributes significantly to the global burden of diseases and is a substantial cost to the society. The neurochemical mechanisms regulating alcohol mediated behaviors is complex and in more recent years a new physiological role of the gut-brain peptides, traditionally known to regulate appetite and food intake, have been suggested. Indeed, regulators of alcohol-mediated behaviors. One of these gut-brain peptides is the annorexigenic peptide glucagon-like peptide-1 (GLP-1), Preclinical studies show that GLP-1 receptor activation, either by GLP-1 or analogues, attenuate the ability of alcohol to activate the mesolimbic dopamine system as well as decrease alcohol consumption and operant self-administration. In further support for the endogenous GLP-1 system in addiction processes are the experimental data showing that a GLP-1 receptor antagonist increases alcohol intake. Moreover, GLP-1 receptor agonists prevent the ability of other addictive drugs to activate the mesolimbic dopamine system. The number of clinical studies is limited, but show i) that genetic variation in the GLP-1 receptor gene is associated with alcohol addiction as well as increased alcohol infusion in humans, ii) that plasma levels of GLP-1 are associated with the subjective experience of cocaine and iii) that a GLP-1 receptor agonist reduces alcohol intake in patients with type-2 diabetes mellitus. These experimental and clinical studies raises the concern that clinically available GLP-1 receptor agonists deserves to be tested as potential treatments of patients with addictive disorders including alcohol addiction. This article is part of the Special Issue entitled 'Metabolic Impairment as Risk Factors for Neurodegenerative Disorders.'
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Affiliation(s)
- Elisabet Jerlhag
- Department of Pharmacology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Medicinaregatan 13A, SE-405 30 Gothenburg, Sweden.
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26
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Bickel WK, Mellis AM, Snider SE, Athamneh LN, Stein JS, Pope DA. 21st century neurobehavioral theories of decision making in addiction: Review and evaluation. Pharmacol Biochem Behav 2018; 164:4-21. [PMID: 28942119 PMCID: PMC5747999 DOI: 10.1016/j.pbb.2017.09.009] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Revised: 08/24/2017] [Accepted: 09/12/2017] [Indexed: 01/21/2023]
Abstract
This review critically examines neurobehavioral theoretical developments in decision making in addiction in the 21st century. We specifically compare each theory reviewed to seven benchmarks of theoretical robustness, based on their ability to address: why some commodities are addictive; developmental trends in addiction; addiction-related anhedonia; self-defeating patterns of behavior in addiction; why addiction co-occurs with other unhealthy behaviors; and, finally, means for the repair of addiction. We have included only self-contained theories or hypotheses which have been developed or extended in the 21st century to address decision making in addiction. We thus review seven distinct theories of decision making in addiction: learning theories, incentive-sensitization theory, dopamine imbalance and systems models, opponent process theory, strength models of self-control failure, the competing neurobehavioral decision systems theory, and the triadic systems theory of addiction. Finally, we have directly compared the performance of each of these theories based on the aforementioned benchmarks, and highlighted key points at which several theories have coalesced.
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Affiliation(s)
- Warren K Bickel
- Addiction Recovery Research Center, Virginia Tech Carilion Research Institute, Roanoke, VA, United States; Graduate Program in Translational Biology, Medicine, and Health, Roanoke, VA, United States; Department of Psychology, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States; Department of Neuroscience, Virginia Polytechnic Institute and State University, United States; Faculty of Health Sciences, Virginia Polytechnic Institute and State University, United States; Department of Psychiatry and Behavioral Medicine, Virginia Tech Carilion School of Medicine, United States.
| | - Alexandra M Mellis
- Addiction Recovery Research Center, Virginia Tech Carilion Research Institute, Roanoke, VA, United States; Graduate Program in Translational Biology, Medicine, and Health, Roanoke, VA, United States
| | - Sarah E Snider
- Addiction Recovery Research Center, Virginia Tech Carilion Research Institute, Roanoke, VA, United States
| | - Liqa N Athamneh
- Addiction Recovery Research Center, Virginia Tech Carilion Research Institute, Roanoke, VA, United States; Graduate Program in Translational Biology, Medicine, and Health, Roanoke, VA, United States
| | - Jeffrey S Stein
- Addiction Recovery Research Center, Virginia Tech Carilion Research Institute, Roanoke, VA, United States
| | - Derek A Pope
- Addiction Recovery Research Center, Virginia Tech Carilion Research Institute, Roanoke, VA, United States
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Panlilio LV, Justinova Z. Preclinical Studies of Cannabinoid Reward, Treatments for Cannabis Use Disorder, and Addiction-Related Effects of Cannabinoid Exposure. Neuropsychopharmacology 2018; 43:116-141. [PMID: 28845848 PMCID: PMC5719102 DOI: 10.1038/npp.2017.193] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 08/17/2017] [Accepted: 08/22/2017] [Indexed: 12/21/2022]
Abstract
Cannabis use has become increasingly accepted socially and legally, for both recreational and medicinal purposes. Without reliable information about the effects of cannabis, people cannot make informed decisions regarding its use. Like alcohol and tobacco, cannabis can have serious adverse effects on health, and some people have difficulty discontinuing their use of the drug. Many cannabis users progress to using and becoming addicted to other drugs, but the reasons for this progression are unclear. The natural cannabinoid system of the brain is complex and involved in many functions, including brain development, reward, emotion, and cognition. Animal research provides an objective and controlled means of obtaining information about: (1) how cannabis affects the brain and behavior, (2) whether medications can be developed to treat cannabis use disorder, and (3) whether cannabis might produce lasting changes in the brain that increase the likelihood of becoming addicted to other drugs. This review explains the tactics used to address these issues, evaluates the progress that has been made, and offers some directions for future research.
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Affiliation(s)
- Leigh V Panlilio
- Preclinical Pharmacology Section, Behavioral Neuroscience Research Branch, Intramural Research Program, National Institute on Drug Abuse, NIH, DHHS, Baltimore, MD, USA
| | - Zuzana Justinova
- Preclinical Pharmacology Section, Behavioral Neuroscience Research Branch, Intramural Research Program, National Institute on Drug Abuse, NIH, DHHS, Baltimore, MD, USA
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Skupio U, Sikora M, Korostynski M, Wawrzczak-Bargiela A, Piechota M, Ficek J, Przewlocki R. Behavioral and transcriptional patterns of protracted opioid self-administration in mice. Addict Biol 2017; 22:1802-1816. [PMID: 27578564 DOI: 10.1111/adb.12449] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Revised: 08/10/2016] [Accepted: 08/11/2016] [Indexed: 12/31/2022]
Abstract
Chronic exposure to opioids induces adaptations in brain function that lead to the formation of the behavioral and physiological symptoms of drug dependence and addiction. Animal models commonly used to test these symptoms typically last less than two weeks, which is presumably too short to observe the alterations in the brain that accompany drug addiction. Here, we analyzed the phenotypic and molecular effects of nearly lifelong morphine or saccharin intake in C57BL/6J mice. We used multiple paradigms to evaluate the symptoms of compulsive drug intake: a progressive ratio schedule, intermittent access and a schedule involving a risk of punishment were programmed into an automated IntelliCage system. Gene expression profiles were evaluated in the striatum using whole-genome microarrays and further validated using quantitative polymerase chain reaction in the striatum and the prefrontal cortex. Mice voluntary self-administering morphine showed addiction-related behavioral pattern that included: higher motivation to work for a drug reward, increased reward seeking and increased craving. The analysis of molecular changes revealed a tolerance effect in the transcriptional response to morphine injection (20 mg/kg, ip), as well as some long-lasting alterations in gene expression profiles between the analyzed groups of animals. Interestingly, among the morphine-drinking animals, certain transcriptional profiles were found to be associated with alterations in behavior. In conclusion, our model represents a novel approach for investigating the behavioral and molecular mechanisms underlying opioid addiction. Prolonged morphine intake caused adaptive processes in the brain that manifested as altered behavior and transcriptional sensitivity to opioids.
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Affiliation(s)
- Urszula Skupio
- Department of Molecular Neuropharmacology, Institute of Pharmacology; Polish Academy of Sciences; Poland
| | - Magdalena Sikora
- Department of Molecular Neuropharmacology, Institute of Pharmacology; Polish Academy of Sciences; Poland
| | - Michal Korostynski
- Department of Molecular Neuropharmacology, Institute of Pharmacology; Polish Academy of Sciences; Poland
| | | | - Marcin Piechota
- Department of Molecular Neuropharmacology, Institute of Pharmacology; Polish Academy of Sciences; Poland
| | - Joanna Ficek
- Department of Molecular Neuropharmacology, Institute of Pharmacology; Polish Academy of Sciences; Poland
| | - Ryszard Przewlocki
- Department of Molecular Neuropharmacology, Institute of Pharmacology; Polish Academy of Sciences; Poland
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A Feedforward Inhibitory Circuit Mediated by CB1-Expressing Fast-Spiking Interneurons in the Nucleus Accumbens. Neuropsychopharmacology 2017; 42:1146-1156. [PMID: 27929113 PMCID: PMC5506784 DOI: 10.1038/npp.2016.275] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2016] [Revised: 11/18/2016] [Accepted: 12/03/2016] [Indexed: 11/08/2022]
Abstract
The nucleus accumbens (NAc) gates motivated behaviors through the functional output of principle medium spiny neurons (MSNs), whereas dysfunctional output of NAc MSNs contributes to a variety of psychiatric disorders. Fast-spiking interneurons (FSIs) are sparsely distributed throughout the NAc, forming local feedforward inhibitory circuits. It remains elusive how FSI-based feedforward circuits regulate the output of NAc MSNs. Here, we investigated a distinct subpopulation of NAc FSIs that express the cannabinoid receptor type-1 (CB1). Using a combination of paired electrophysiological recordings and pharmacological approaches, we characterized and compared feedforward inhibition of NAc MSNs from CB1+ FSIs and lateral inhibition from recurrent MSN collaterals. We observed that CB1+ FSIs exerted robust inhibitory control over a large percentage of nearby MSNs in contrast to local MSN collaterals that provided only sparse and weak inhibitory input to their neighboring MSNs. Furthermore, CB1+ FSI-mediated feedforward inhibition was preferentially suppressed by endocannabinoid (eCB) signaling, whereas MSN-mediated lateral inhibition was unaffected. Finally, we demonstrated that CB1+ FSI synapses onto MSNs are capable of undergoing experience-dependent long-term depression in a voltage- and eCB-dependent manner. These findings demonstrated that CB1+ FSIs are a major source of local inhibitory control of MSNs and a critical component of the feedforward inhibitory circuits regulating the output of the NAc.
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Glueck E, Ginder D, Hyde J, North K, Grimm JW. Effects of dopamine D1 and D2 receptor agonists on environmental enrichment attenuated sucrose cue reactivity in rats. Psychopharmacology (Berl) 2017; 234:815-825. [PMID: 28032125 PMCID: PMC5891328 DOI: 10.1007/s00213-016-4516-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Accepted: 12/17/2016] [Indexed: 12/25/2022]
Abstract
RATIONALE Acute or chronic environmental enrichment (EE) reduces sucrose cue reactivity in rats. This effect may be mediated by dopamine receptors. OBJECTIVES We examined whether dopamine D1 or D2 receptor agonism could reverse the EE effect. We also examined whether any reversal effects would vary with the incubation of sucrose craving. METHODS Following 10 days (2 h/day) of sucrose self-administration, rats experienced either 1 or 30 days of forced abstinence and either overnight (acute) or 29 day (chronic) EE. D1 (SKF 81297; 0, 0.3, or 1 mg/kg) or D2 (quinpirole; 0, 0.1, or 0.3 mg/kg) agonist was administered systemically immediately prior to a subsequent 2-h cue reactivity test the next day (n = 9-12 per group). RESULTS Dose-dependent effects were limited to the day 1 test. High doses of the agonists increased day 1 acute EE cue reactivity to levels comparable to control animals. On the day 30 test, SKF 81297 increased cue reactivity in acute EE, chronic EE, and control rats. In contrast, quinpirole resulted in similar cue reactivity for control and enriched rats, more from a reduction in responding by controls vs. a recovery of responding by EE-experienced rats. CONCLUSIONS Both D1 and D2 receptors may be involved in the acute EE-mediated decrease in cue reactivity observed following 1 day of forced abstinence. In contrast, at 30 days of forced abstinence, D1 receptors may be critical in cue reactivity as SKF 81297 was effective at both restoring responding of enriched animals and potentiating responding of controls.
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Affiliation(s)
- Edwin Glueck
- Department of Psychology and Program in Behavioral Neuroscience, Western Washington University, 516 High Street, Bellingham, WA 98225-9172, USA
| | - Darren Ginder
- Department of Psychology and Program in Behavioral Neuroscience, Western Washington University, 516 High Street, Bellingham, WA 98225-9172, USA
| | - Jeff Hyde
- Department of Psychology and Program in Behavioral Neuroscience, Western Washington University, 516 High Street, Bellingham, WA 98225-9172, USA
| | - Katherine North
- Department of Psychology and Program in Behavioral Neuroscience, Western Washington University, 516 High Street, Bellingham, WA 98225-9172, USA
| | - Jeffrey W. Grimm
- Department of Psychology and Program in Behavioral Neuroscience, Western Washington University, 516 High Street, Bellingham, WA 98225-9172, USA
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Counterconditioning During Reconsolidation Prevents Relapse of Cocaine Memories. Neuropsychopharmacology 2017; 42:716-726. [PMID: 27468918 PMCID: PMC5240172 DOI: 10.1038/npp.2016.140] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Revised: 07/19/2016] [Accepted: 07/25/2016] [Indexed: 11/08/2022]
Abstract
Relapse to drug abuse is often caused by exposure to drug-associated cues that evoke craving. Therefore, disruption of the cue-drug memory can prevent relapse. Memories destabilize and become temporarily labile upon their retrieval, and re-stabilize in a process termed reconsolidation. Pharmacological disruption of reconsolidation prevents relapse in animal models, yet may evoke side effects. Therefore, behavioral procedures capable of preventing cue-induced craving and relapse are extremely valuable. Aversion therapies, in which drug-paired cues are re-associated (counterconditioned) with aversive consequences, have limited success, because the previous cue-drug memory may recover, triggering relapse. Here, we prevented the memory recovery and relapse to cocaine seeking by applying aversive counterconditioning during memory reconsolidation. Mice were trained to seek cocaine in a conditioned place preference procedure. The cocaine-associated compartment was then counterconditioned with lithium chloride (LiCl)-induced malaise, preceded by a brief exposure to the compartment (memory retrieval). Relapse was assessed in a reinstatement test. We found that aversive counterconditioning conducted shortly after memory retrieval (during reconsolidation) induced a long-lasting prevention of relapse to cocaine seeking. However, mice relapsed when counterconditioned without, before, or long after memory retrieval, or when receiving LiCl without place counterconditioning. Our findings suggest that post-retrieval aversive counterconditioning leads to relapse prevention, possibly by replacing the cue-drug with a cue-aversion memory, thereby the cue ceases to evoke craving. Moreover, we found that a similar memory replacement procedure prevented relapse of conditioned place aversion. Hence, this novel procedure can also prevent relapse of aversive memories, providing a safe approach to alter various maladaptive behaviors.
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Rothwell PE. Autism Spectrum Disorders and Drug Addiction: Common Pathways, Common Molecules, Distinct Disorders? Front Neurosci 2016; 10:20. [PMID: 26903789 PMCID: PMC4742554 DOI: 10.3389/fnins.2016.00020] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Accepted: 01/15/2016] [Indexed: 11/17/2022] Open
Abstract
Autism spectrum disorders (ASDs) and drug addiction do not share substantial comorbidity or obvious similarities in etiology or symptomatology. It is thus surprising that a number of recent studies implicate overlapping neural circuits and molecular signaling pathways in both disorders. The purpose of this review is to highlight this emerging intersection and consider implications for understanding the pathophysiology of these seemingly distinct disorders. One area of overlap involves neural circuits and neuromodulatory systems in the striatum and basal ganglia, which play an established role in addiction and reward but are increasingly implicated in clinical and preclinical studies of ASDs. A second area of overlap relates to molecules like Fragile X mental retardation protein (FMRP) and methyl CpG-binding protein-2 (MECP2), which are best known for their contribution to the pathogenesis of syndromic ASDs, but have recently been shown to regulate behavioral and neurobiological responses to addictive drug exposure. These shared pathways and molecules point to common dimensions of behavioral dysfunction, including the repetition of behavioral patterns and aberrant reward processing. The synthesis of knowledge gained through parallel investigations of ASDs and addiction may inspire the design of new therapeutic interventions to correct common elements of striatal dysfunction.
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Affiliation(s)
- Patrick E Rothwell
- Department of Neuroscience, University of Minnesota Minneapolis, MN, USA
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Dong Y. Silent Synapse-Based Circuitry Remodeling in Drug Addiction. Int J Neuropsychopharmacol 2015; 19:pyv136. [PMID: 26721952 PMCID: PMC4886671 DOI: 10.1093/ijnp/pyv136] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Accepted: 12/14/2015] [Indexed: 12/01/2022] Open
Abstract
Exposure to cocaine, and likely other drugs of abuse, generates α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor-silent glutamatergic synapses in the nucleus accumbens. These immature synaptic contacts evolve after drug withdrawal to redefine the neurocircuital properties. These results raise at least three critical questions: (1) what are the molecular and cellular mechanisms that mediate drug-induced generation of silent synapses; (2) how are neurocircuits remodeled upon generation and evolution of drug-generated silent synapses; and (3) what behavioral consequences are produced by silent synapse-based circuitry remodeling? This short review analyzes related experimental results, and extends them to some speculations.
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Affiliation(s)
- Yan Dong
- Department of Neuroscience, University of Pittsburgh, Pennsylvania (Dr Dong).
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D'Souza MS. Glutamatergic transmission in drug reward: implications for drug addiction. Front Neurosci 2015; 9:404. [PMID: 26594139 PMCID: PMC4633516 DOI: 10.3389/fnins.2015.00404] [Citation(s) in RCA: 84] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Accepted: 10/12/2015] [Indexed: 12/12/2022] Open
Abstract
Individuals addicted to drugs of abuse such as alcohol, nicotine, cocaine, and heroin are a significant burden on healthcare systems all over the world. The positive reinforcing (rewarding) effects of the above mentioned drugs play a major role in the initiation and maintenance of the drug-taking habit. Thus, understanding the neurochemical mechanisms underlying the reinforcing effects of drugs of abuse is critical to reducing the burden of drug addiction in society. Over the last two decades, there has been an increasing focus on the role of the excitatory neurotransmitter glutamate in drug addiction. In this review, pharmacological and genetic evidence supporting the role of glutamate in mediating the rewarding effects of the above described drugs of abuse will be discussed. Further, the review will discuss the role of glutamate transmission in two complex heterogeneous brain regions, namely the nucleus accumbens (NAcc) and the ventral tegmental area (VTA), which mediate the rewarding effects of drugs of abuse. In addition, several medications approved by the Food and Drug Administration that act by blocking glutamate transmission will be discussed in the context of drug reward. Finally, this review will discuss future studies needed to address currently unanswered gaps in knowledge, which will further elucidate the role of glutamate in the rewarding effects of drugs of abuse.
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Affiliation(s)
- Manoranjan S D'Souza
- Pharmaceutical and Biomedical Sciences, Raabe College of Pharmacy, Ohio Northern University Ada, OH, USA
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35
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Gomez JL, Ryabinin AE. The effects of ghrelin antagonists [D-Lys(3) ]-GHRP-6 or JMV2959 on ethanol, water, and food intake in C57BL/6J mice. Alcohol Clin Exp Res 2015; 38:2436-44. [PMID: 25257292 DOI: 10.1111/acer.12499] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Accepted: 05/21/2014] [Indexed: 12/20/2022]
Abstract
BACKGROUND Alcohol use and abuse patterns have created a need for novel treatment models. Current research has turned its focus on reward pathways associated with intrinsic necessities, such as feeding. Theories suggest that drugs of abuse seize control of natural reward pathways and dysregulate normal function, leading to chronic addiction. One such pathway involving the hunger stimulating peptide, ghrelin, is the focus of our study. METHODS Male C57BL/6J mice were randomly assigned to groups and treated with vehicle or a ghrelin antagonist, either [D-Lys(3) ]-GHRP-6 (DLys) or JMV2959. Three experiments tested ghrelin antagonism using different doses; experiment 1 tested 12 mg/kg JMV2959; experiment 2 tested 15 mg/kg DLys; experiment 3 tested 9 mg/kg JMV2959. Using a 2-bottle choice 24-hour access paradigm, data were collected for ethanol intake, preference, water intake, and food intake at 4 and 24 hours after injection. RESULTS Experiment 1 showed that 12 mg/kg of JMV2959 decreased ethanol, water, and food intake, without affecting preference. Experiment 2 showed that 15 mg/kg of DLys decreased ethanol intake, preference, and water intake only on the first day of treatment. Experiment 3 showed that 9 mg/kg of JMV2959 decreased only ethanol and food intake. No change was seen during deprivation, and JMV2959 was still effective at reducing ethanol intake upon reintroduction. Despite the change in food intake, there were no differences in body weight throughout the experiments. It should be noted that the majority of significant effects were only found 4 hours postinjection. CONCLUSIONS The results show that compounds that block ghrelin receptor activity are effective at decreasing ethanol intake. However, DLys was only effective at reducing intake and preference on the first day, suggesting a quick tolerance and selectivity for ethanol. JMV2959 consistently reduced ethanol intake, but at the higher dose also reduced all other consummatory behaviors. Thus, ghrelin antagonists provide a viable potential for treatment of alcohol abuse disorders, but further research is needed to determine an appropriate dose and administration paradigm.
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Affiliation(s)
- Juan L Gomez
- Department of Behavioral Neuroscience, Oregon Health and Science University, Portland, Oregon
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Abstract
There is abundant evidence that the dopamine (DA) neurons that project to the nucleus accumbens play a central role in neurobiological mechanisms underpinning drug dependence. This chapter considers the ways in which these projections facilitate the addiction to nicotine and tobacco. It focuses on the complimentary roles of the two principal subdivisions of the nucleus accumbens, the accumbal core and shell, in the acquisition and maintenance of nicotine-seeking behavior. The ways in which tonic and phasic firing of the neurons contributes to the ways in which the accumbens mediate the behavioral responses to nicotine are also considered. Experimental studies suggest that nicotine has relatively weak addictive properties which are insufficient to explain the powerful addictive properties of tobacco smoke. This chapter discusses hypotheses that seek to explain this conundrum. They implicate both discrete sensory stimuli closely paired with the delivery of tobacco smoke and contextual stimuli habitually associated with the delivery of the drug. The mechanisms by which each type of stimulus influence tobacco dependence are hypothesized to depend upon the increased DA release and overflow, respectively, in the two subdivisions of the accumbens. It is suggested that a majority of pharmacotherapies for tobacco dependence are not more successful because they fail to address this important aspect of the dependence.
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Affiliation(s)
- David J K Balfour
- Medical Research Institute, Division of Neuroscience, Ninewells Hospital and Medical School, Dundee, DD1 9SY, Scotland,
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Abstract
Drug addiction is a syndrome of dysregulated motivation, evidenced by intense drug craving and compulsive drug-seeking behavior. In the search for 'common neurobiological substrates of addiction to different classes of drugs, behavioral neuroscientists have attempted to determine the neural basis for a number of motivational concepts and describe how they are changed by repeated drug use. Here, we describe these concepts and summarize previous work describing three major neural systems that play distinct roles in different conceptual aspects of motivation: (1) a nigrostriatal system that is involved in two forms of instrumental learning, (2) a ventral striatal system that is involved in Pavlovian incentive motivation and negative reinforcement, and (3) frontal cortical areas that regulate decision making and motivational processes. Within striatal systems, drug addiction can involve a transition from goal-oriented, incentive processes to automatic, habit-based responding. In the cortex, weak inhibitory control is a predisposing factor to, as well as a consequence of, repeated drug intake. However, these transitions are not absolute, and addiction can occur without a transition to habit-based responding, occurring as a result of the overvaluation of drug outcomes and hypersensitivity to incentive properties of drug-associated cues. Finally, we point out that addiction is not monolithic and can depend not only on individual differences between addicts, but also on the neurochernical action of specific drug classes.
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Dong Y, Nestler EJ. The neural rejuvenation hypothesis of cocaine addiction. Trends Pharmacol Sci 2014; 35:374-83. [PMID: 24958329 DOI: 10.1016/j.tips.2014.05.005] [Citation(s) in RCA: 115] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Revised: 05/27/2014] [Accepted: 05/27/2014] [Indexed: 12/16/2022]
Abstract
A leading hypothesis guiding current molecular and cellular research into drug addiction conceptualizes key aspects of addiction as a form of memory in which common neuroplasticity mechanisms that mediate normal learning and memory processes are 'hijacked' by exposure to drugs of abuse to produce pathologic addiction-related memories. Such addiction-related memories are particularly robust and long-lasting and once formed are less amenable to updating. Here we propose a neural rejuvenation hypothesis of cocaine addiction. According to this hypothesis, repeated exposure to drugs of abuse induces some plasticity mechanisms normally associated with brain development within the reward circuitry that mediate the highly efficient and unusually stable memory abnormalities that characterize addiction.
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Affiliation(s)
- Yan Dong
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA15260, USA.
| | - Eric J Nestler
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
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“Sexy stimulants”: The interaction between psychomotor stimulants and sexual behavior in the female brain. Pharmacol Biochem Behav 2014; 121:53-61. [DOI: 10.1016/j.pbb.2013.11.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Accepted: 11/06/2013] [Indexed: 11/19/2022]
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Serum proteomic analysis reveals high frequency of haptoglobin deficiency and elevated thyroxine level in heroin addicts. PLoS One 2014; 9:e95345. [PMID: 24743330 PMCID: PMC3990700 DOI: 10.1371/journal.pone.0095345] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Accepted: 03/25/2014] [Indexed: 11/19/2022] Open
Abstract
Heroin addiction is a chronic, complex disease, often accompanied by other concomitant disorders, which may encumber effective prevention and treatment. To explore the differences in expression profiles of serum proteins in control and heroin addicts, we used two-dimensional electrophoresis coupled to MALDI-TOF/TOF, and identified 4 proteins of interest. Following validation of the increase in serum transthyretin, we assessed serum levels of thyroid stimulating hormone (TSH), triiodothyronine (T3), and thyroxine (T4), and observed a robust increase in T4 in heroin addicts compared to controls. In addition, we performed haptoglobin (Hp) phenotyping, and showed that the frequency of Hp0 (serum devoid of haptoglobin) was significantly higher in heroin addicts. Altogether, these findings indicated that: (1) thyroid hormone imbalance is present in heroin addicts; (2) anhaptoglobinemia (Hp0) might a risk factor or a deleterious effect of heroin abuse.
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Food consumption and weight gain after cessation of chronic amphetamine administration. Appetite 2014; 78:76-80. [PMID: 24667154 DOI: 10.1016/j.appet.2014.03.013] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2014] [Revised: 03/04/2014] [Accepted: 03/12/2014] [Indexed: 12/31/2022]
Abstract
Cessation of drug use often coincides with increased food consumption and weight gain in recovering addicts. However, it is not known whether this phenomenon (particularly the weight gain) is uniquely human, or whether it represents a consequence of drug cessation common across species. To address this issue, rats (n = 10/group) were given systemic injections of D-amphetamine (3 mg/kg) or an equal volume of saline vehicle for 9 consecutive days. Beginning 2 days after the final injection, rats were given free access to a highly palatable food mixture (consisting of sugar and butter) along with their standard chow diet, and food consumption and body weight were measured every 48 h for 30 days. Consistent with clinical observations, amphetamine-treated rats showed a greater increase in body weight over the course of the 30 days relative to vehicle-treated rats. Surprisingly, there was no difference in highly palatable food consumption between amphetamine- and vehicle-treated groups, but the amphetamine-treated group consumed significantly more standard chow than the control group. The finding that a history of chronic amphetamine exposure increases food consumption is consistent with previous work in humans showing that withdrawal from drugs of abuse is associated with overeating and weight gain. The current findings may reflect amphetamine-induced sensitization of mechanisms involved in reward motivation, suggesting that weight gain following drug cessation in humans could be due to similar mechanisms.
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Barker DJ, Simmons SJ, Servilio LC, Bercovicz D, Ma S, Root DH, Pawlak AP, West MO. Ultrasonic vocalizations: evidence for an affective opponent process during cocaine self-administration. Psychopharmacology (Berl) 2014; 231:909-18. [PMID: 24197178 PMCID: PMC3989366 DOI: 10.1007/s00213-013-3309-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Accepted: 09/29/2013] [Indexed: 12/01/2022]
Abstract
RATIONALE Preclinical models of cocaine addiction in the rodent have shown that cocaine induces both positive and negative affective states. These observations have led to the notion that the initial positive/euphoric state induced by cocaine administration may be followed by an opposing, negative process. In the rodent, one method for inferring positive and negative affective states involves measuring their ultrasonic vocalizations (USVs). Previous USV recordings from our laboratory suggested that the transition between positive and negative affect might involve decaying or sub-satiety levels of self-administered cocaine. OBJECTIVES In order to explicitly test the role of cocaine levels on these affective states, the present study examined USVs when calculated body levels of cocaine were clamped (i.e., held at a constant level via experimenter-controlled infusions) at, below, or above subjects' self-determined drug satiety thresholds. RESULTS USVs indicated that (1) positive affect was predominantly observed during the drug loading period, but declined quickly to near zero during maintenance and exhibited little relation to calculated drug level, and (2) in contrast, negative affect was observed at sub-satiety cocaine levels, but was relatively absent when body levels of cocaine were clamped at or above subjects' satiety thresholds. CONCLUSIONS The results reinforce the opponent-process hypothesis of addiction and suggest that an understanding of the mechanisms underlying negative affect might serve to inform behavioral and pharmacological therapies.
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Affiliation(s)
- David J. Barker
- Department of Psychology, Rutgers University, 152 Frelinghuysen Road, Piscataway, New Jersey, 08854, USA
| | - Steven J. Simmons
- Department of Psychology, Rutgers University, 152 Frelinghuysen Road, Piscataway, New Jersey, 08854, USA
| | - Lisa C. Servilio
- Department of Psychology, Rutgers University, 152 Frelinghuysen Road, Piscataway, New Jersey, 08854, USA
| | - Danielle Bercovicz
- Department of Psychology, Rutgers University, 152 Frelinghuysen Road, Piscataway, New Jersey, 08854, USA
| | - Sisi Ma
- Department of Psychology, Rutgers University, 152 Frelinghuysen Road, Piscataway, New Jersey, 08854, USA
| | - David H. Root
- Neuronal Networks Section: Integrative Neuroscience Research Branch, National Institute on Drug Abuse, 251 Bayview Blvd, Suite 200, Baltimore, MD 21224
| | - Anthony P. Pawlak
- Department of Psychology, Rutgers University, 152 Frelinghuysen Road, Piscataway, New Jersey, 08854, USA
| | - Mark O. West
- Department of Psychology, Rutgers University, 152 Frelinghuysen Road, Piscataway, New Jersey, 08854, USA
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A general theory of transition to addiction it was and a general theory of transition to addiction it is: reply to the commentaries of Ahmed, Badiani, George & Koob, Kalivas & Gipson, and Tiffany. Psychopharmacology (Berl) 2014; 231:3929-37. [PMID: 24908270 PMCID: PMC4159574 DOI: 10.1007/s00213-014-3628-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Accepted: 05/13/2014] [Indexed: 02/04/2023]
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Réus GZ, Abelaira HM, dos Santos MAB, Carlessi AS, Tomaz DB, Neotti MV, Liranço JLG, Gubert C, Barth M, Kapczinski F, Quevedo J. Ketamine and imipramine in the nucleus accumbens regulate histone deacetylation induced by maternal deprivation and are critical for associated behaviors. Behav Brain Res 2013; 256:451-6. [PMID: 24004850 DOI: 10.1016/j.bbr.2013.08.041] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Revised: 08/20/2013] [Accepted: 08/24/2013] [Indexed: 10/26/2022]
Abstract
Studies indicate that histone deacetylation is important for long term changes related to stress and antidepressant treatment. The present study aimed to evaluate the effects of the classic antidepressant imipramine, and of an antagonist of the N-methyl-d-asparte (NMDA) receptor, ketamine, on behavior and histone deacetylase (HDAC) activity in the brains of maternally deprived adult rats. To this aim, deprived and non-deprived (control) male Wistar rats were divided into the following groups: non-deprived+saline; non-deprived+imipramine (30 mg/kg); non-deprived+ketamine (15 mg/kg); deprived+saline; deprived+imipramine (30 mg/kg); and deprived+ketamine (15 mg/kg). The drugs were administrated once a day for 14 days during their adult phase. Their behavior were then assessed using the forced swimming and open field tests. In addition, the HDAC activity was evaluated in the prefrontal cortex, hippocampus, amygdala and nucleus accumbens using the kit ELISA-sandwich test. In deprived rats treated with saline, we observed an increase in the immobility time, but treatments with imipramine and ketamine were able to reverse this alteration, decreasing the immobility time. Also, there was a decrease on number of crossings with imipramine treatment in non-deprived rats, and an increase on number of crossings with ketamine treatment in deprived rats. The HDAC activity did not alter in the prefrontal cortex, hippocampus and amygdala by deprivation or via treatment with imipramine or ketamine. However, in the nucleus accumbens we observed an increase of HDAC activity in the deprived rats, and interestingly, imipramine and ketamine treatments were able to decrease HDAC activity in this brain area. These findings provide a novel insight into the epigenetic regulation of histone deacetylase in the nucleus accumbens caused by imipramine and ketamine, and indicate that molecular events are necessary to reverse specific stress-induced behavior.
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Affiliation(s)
- Gislaine Z Réus
- Laboratório de Neurociências, Instituto Nacional de Ciência e Tecnologia Translacional em Medicina (INCT-TM), and Núcleo de Excelência em Neurociências Aplicadas de Santa Catarina (NENASC), Programa de Pós-Graduação em Ciências da Saúde, Unidade Acadêmica de Ciências da Saúde, Universidade do Extremo Sul Catarinense, 88806-000 Criciúma, SC, Brazil.
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Ishikawa M, Otaka M, Neumann PA, Wang Z, Cook JM, Schlüter OM, Dong Y, Huang YH. Exposure to cocaine regulates inhibitory synaptic transmission from the ventral tegmental area to the nucleus accumbens. J Physiol 2013; 591:4827-41. [PMID: 23918773 DOI: 10.1113/jphysiol.2013.262915] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Synaptic projections from the ventral tegmental area (VTA) to the nucleus accumbens (NAc) make up the backbone of the brain reward pathway, a neural circuit that mediates behavioural responses elicited by natural rewards as well as by cocaine and other drugs of abuse. In addition to the well-known modulatory dopaminergic projection, the VTA also provides fast excitatory and inhibitory synaptic input to the NAc, directly regulating NAc medium spiny neurons (MSNs). However, the cellular nature of VTA-to-NAc fast synaptic transmission and its roles in drug-induced adaptations are not well understood. Using viral-mediated in vivo expression of channelrhodopsin 2, the present study dissected fast excitatory and inhibitory synaptic transmission from the VTA to NAc MSNs in rats. Our results suggest that, following repeated exposure to cocaine (15 mg kg(-1) day(-1) × 5 days, i.p., 1 or 21 day withdrawal), a presynaptic enhancement of excitatory transmission and suppression of inhibitory transmission occurred at different withdrawal time points at VTA-to-NAc core synapses. In contrast, no postsynaptic alterations were detected at either type of synapse. These results suggest that changes in VTA-to-NAc fast excitatory and inhibitory synaptic transmissions may contribute to cocaine-induced alteration of the brain reward circuitry.
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Affiliation(s)
- Masago Ishikawa
- Y. Dong, Y. Huang: University of Pittsburgh, 210 Langley Hall, Department of Neuroscience, PA 15260, USA. ;
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Abstract
As a classic neuromodulator, dopamine has long been thought to modulate, rather than trigger, synaptic plasticity. In contrast, our present results demonstrate that within the parallel projections of dopaminergic and GABAergic terminals from the ventral tegmental area to the nucleus accumbens core (NAcCo), action-potential-activated release of dopamine heterosynaptically triggers LTD at GABAergic synapses, which is likely mediated by activating presynaptically located dopamine D1 class receptors and expressed by inhibiting presynaptic release of GABA. Moreover, this dopamine-mediated heterosynaptic LTD is abolished after withdrawal from cocaine exposure. These results suggest that action-potential-dependent dopamine release triggers very different cellular consequences from those induced by volume release or pharmacological manipulation. Activation of the ventral tegmental area to NAcCo projections is essential for emotional and motivational responses. This dopamine-mediated LTD allows a flexible output of NAcCo neurons, whereas disruption of this LTD may contribute to the rigid emotional and motivational state observed in addicts during cocaine withdrawal.
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Social modulation of learned behavior by dopamine in the basal ganglia: Insights from songbirds. ACTA ACUST UNITED AC 2013; 107:219-29. [DOI: 10.1016/j.jphysparis.2012.09.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2012] [Revised: 08/22/2012] [Accepted: 09/18/2012] [Indexed: 01/25/2023]
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D'Souza MS, Markou A. The "stop" and "go" of nicotine dependence: role of GABA and glutamate. Cold Spring Harb Perspect Med 2013; 3:3/6/a012146. [PMID: 23732855 DOI: 10.1101/cshperspect.a012146] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Nicotine plays an important role in the initiation and maintenance of tobacco smoking. Importantly, chronic nicotine exposure alters the function of brain reward systems, resulting in the development of a nicotine-dependent state. This nicotine-dependent state is associated with aversive affective and somatic signs upon abstinence from smoking, often leading to relapse in abstinent smokers. This article reviews the role of the major excitatory and inhibitory neurotransmitters glutamate and γ-aminobutyric acid (GABA), respectively, in both the reinforcing effects of nicotine and development of nicotine dependence. Evidence suggests that blockade of glutamatergic neurotransmission attenuates both nicotine intake and nicotine seeking. In contrast, both nicotine intake and nicotine seeking are attenuated when GABA neurotransmission is facilitated. In conclusion, medications that either attenuate/negatively modulate glutamatergic neurotransmission or facilitate/positively modulate GABA neurotransmission may be useful for promoting smoking cessation in humans.
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Affiliation(s)
- Manoranjan S D'Souza
- Department of Psychiatry, School of Medicine, University of California San Diego, La Jolla, California 92093, USA
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