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Smith AC, Ghoshal S, Centanni SW, Heyer MP, Corona A, Wills L, Andraka E, Lei Y, O’Connor RM, Caligiuri SP, Khan S, Beaumont K, Sebra RP, Kieffer BL, Winder DG, Ishikawa M, Kenny PJ. A master regulator of opioid reward in the ventral prefrontal cortex. Science 2024; 384:eadn0886. [PMID: 38843332 PMCID: PMC11323237 DOI: 10.1126/science.adn0886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Accepted: 04/17/2024] [Indexed: 06/16/2024]
Abstract
In addition to their intrinsic rewarding properties, opioids can also evoke aversive reactions that protect against misuse. Cellular mechanisms that govern the interplay between opioid reward and aversion are poorly understood. We used whole-brain activity mapping in mice to show that neurons in the dorsal peduncular nucleus (DPn) are highly responsive to the opioid oxycodone. Connectomic profiling revealed that DPn neurons innervate the parabrachial nucleus (PBn). Spatial and single-nuclei transcriptomics resolved a population of PBn-projecting pyramidal neurons in the DPn that express μ-opioid receptors (μORs). Disrupting μOR signaling in the DPn switched oxycodone from rewarding to aversive and exacerbated the severity of opioid withdrawal. These findings identify the DPn as a key substrate for the abuse liability of opioids.
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Affiliation(s)
- Alexander C.W. Smith
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York 10029, USA
- Present address: Department of Neuroscience, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Soham Ghoshal
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York 10029, USA
| | - Samuel W. Centanni
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Mary P. Heyer
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York 10029, USA
| | - Alberto Corona
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York 10029, USA
| | - Lauren Wills
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York 10029, USA
| | - Emma Andraka
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York 10029, USA
| | - Ye Lei
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York 10029, USA
| | - Richard M. O’Connor
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York 10029, USA
| | - Stephanie P.B. Caligiuri
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York 10029, USA
| | - Sohail Khan
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York 10029, USA
| | - Kristin Beaumont
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Robert P. Sebra
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Brigitte L. Kieffer
- Douglas Research Center, Department of Psychiatry, McGill University, Montréal, Quebec, Canada, and INSERM U1114, Department of Psychiatry, University of Strasbourg, Strasbourg, France
| | - Danny G. Winder
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Masago Ishikawa
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York 10029, USA
| | - Paul J. Kenny
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York 10029, USA
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Milella MS, D'Ottavio G, De Pirro S, Barra M, Caprioli D, Badiani A. Heroin and its metabolites: relevance to heroin use disorder. Transl Psychiatry 2023; 13:120. [PMID: 37031205 PMCID: PMC10082801 DOI: 10.1038/s41398-023-02406-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 03/17/2023] [Accepted: 03/21/2023] [Indexed: 04/10/2023] Open
Abstract
Heroin is an opioid agonist commonly abused for its rewarding effects. Since its synthesis at the end of the nineteenth century, its popularity as a recreational drug has ebbed and flowed. In the last three decades, heroin use has increased again, and yet the pharmacology of heroin is still poorly understood. After entering the body, heroin is rapidly deacetylated to 6-monoacetylmorphine (6-MAM), which is then deacetylated to morphine. Thus, drug addiction literature has long settled on the notion that heroin is little more than a pro-drug. In contrast to these former views, we will argue for a more complex interplay among heroin and its active metabolites: 6-MAM, morphine, and morphine-6-glucuronide (M6G). In particular, we propose that the complex temporal pattern of heroin effects results from the sequential, only partially overlapping, actions not only of 6-MAM, morphine, and M6G, but also of heroin per se, which, therefore, should not be seen as a mere brain-delivery system for its active metabolites. We will first review the literature concerning the pharmacokinetics and pharmacodynamics of heroin and its metabolites, then examine their neural and behavioral effects, and finally discuss the possible implications of these data for a better understanding of opioid reward and heroin addiction. By so doing we hope to highlight research topics to be investigated by future clinical and pre-clinical studies.
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Affiliation(s)
- Michele Stanislaw Milella
- Toxicology Unit, Policlinico Umberto I University Hospital, Rome, Italy.
- Laboratory affiliated to the Institute Pasteur Italia-Fondazione Cenci Bolognetti-Department of Physiology and Pharmacology, Sapienza University of Rome, Rome, Italy.
| | - Ginevra D'Ottavio
- Laboratory affiliated to the Institute Pasteur Italia-Fondazione Cenci Bolognetti-Department of Physiology and Pharmacology, Sapienza University of Rome, Rome, Italy
- Santa Lucia Foundation (IRCCS Fondazione Santa Lucia), Rome, Italy
| | - Silvana De Pirro
- Laboratory affiliated to the Institute Pasteur Italia-Fondazione Cenci Bolognetti-Department of Physiology and Pharmacology, Sapienza University of Rome, Rome, Italy
- Norwegian Centre for Addiction Research (SERAF), Faculty of Medicine, University of Oslo, Oslo, Norway
- Sussex Addiction and Intervention Centre (SARIC), School of Psychology, University of Sussex, Brighton, UK
| | | | - Daniele Caprioli
- Laboratory affiliated to the Institute Pasteur Italia-Fondazione Cenci Bolognetti-Department of Physiology and Pharmacology, Sapienza University of Rome, Rome, Italy.
- Santa Lucia Foundation (IRCCS Fondazione Santa Lucia), Rome, Italy.
| | - Aldo Badiani
- Laboratory affiliated to the Institute Pasteur Italia-Fondazione Cenci Bolognetti-Department of Physiology and Pharmacology, Sapienza University of Rome, Rome, Italy.
- Sussex Addiction and Intervention Centre (SARIC), School of Psychology, University of Sussex, Brighton, UK.
- Fondazione Villa Maraini, Rome, Italy.
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3
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Abstract
Drug addiction is a chronic relapsing disorder, and a significant amount of research has been devoted to understand the factors that contribute to the development, loss of control, and persistence of compulsive addictive behaviors. In this review, we provide an overview of various theories of addiction to drugs of abuse and the neurobiology involved in elements of the addiction cycle. Specific focus is devoted to the role of the mesolimbic pathway in acute drug reinforcement and occasional drug use, the role of the mesocortical pathway and associated areas (e.g., the dorsal striatum) in escalation/dependence, and the contribution of these pathways and associated circuits to conditioned responses, drug craving, and loss of behavioral control that may underlie drug relapse. By enhancing the understanding of the neurobiological factors that mediate drug addiction, continued preclinical and clinical research will aid in the development of novel therapeutic interventions that can serve as effective long-term treatment strategies for drug-dependent individuals.
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Affiliation(s)
- Matthew W Feltenstein
- Department of Neuroscience, Medical University of South Carolina, Charleston, South Carolina 29425, USA
| | - Ronald E See
- Department of Neuroscience, Medical University of South Carolina, Charleston, South Carolina 29425, USA
- Department of Psychology, Westmont College, Santa Barbara, California 93108, USA
| | - Rita A Fuchs
- Integrative Physiology and Neuroscience, Washington State University College of Veterinary Medicine, Pullman, Washington 99164-7620, USA
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4
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Galaj E, Han X, Shen H, Jordan CJ, He Y, Humburg B, Bi GH, Xi ZX. Dissecting the Role of GABA Neurons in the VTA versus SNr in Opioid Reward. J Neurosci 2020; 40:8853-8869. [PMID: 33046548 PMCID: PMC7659457 DOI: 10.1523/jneurosci.0988-20.2020] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Revised: 08/22/2020] [Accepted: 09/21/2020] [Indexed: 01/03/2023] Open
Abstract
Opioid reward has traditionally been thought to be mediated by GABA-induced disinhibition of dopamine (DA) neurons in the VTA. However, direct behavioral evidence supporting this hypothesis is still lacking. In this study, we found that the μ opioid receptor (MOR) gene, Oprm1, is highly expressed in GABA neurons, with ∼50% of GABA neurons in the substantia nigra pars reticulata (SNr), ∼30% in the VTA, and ∼70% in the tail of the VTA (also called the rostromedial tegmental nucleus) in male rats. No Oprm1 mRNA was detected in midbrain DA neurons. We then found that optogenetic inhibition of VTA DA neurons reduced intravenous heroin self-administration, whereas activation of these neurons produced robust optical intracranial self-stimulation in DAT-Cre mice, supporting an important role of DA neurons in opioid reward. Unexpectedly, pharmacological blockade of MORs in the SNr was more effective than in the VTA in reducing heroin reward. Optogenetic activation of VTA GABA neurons caused place aversion and inhibited cocaine, but not heroin, self-administration, whereas optogenetic activation of SNr GABA neurons caused a robust increase in heroin self-administration with an extinction pattern, suggesting a compensatory response in drug intake due to reduced heroin reward. In addition, activation of SNr GABA neurons attenuated heroin-primed, but not cue-induced, reinstatement of drug-seeking behavior, whereas inhibition of SNr GABA neurons produced optical intracranial self-stimulation and place preference. Together, these findings suggest that MORs on GABA neurons in the SNr play more important roles in opioid reward and relapse than MORs on VTA GABA neurons.SIGNIFICANCE STATEMENT Opioid reward has long been believed to be mediated by inhibition of GABA interneurons in the VTA that subsequently leads to disinhibition of DA neurons. In this study, we found that more μ opioid receptors (MORs) are expressed in GABA neurons in the neighboring SNr than in the VTA, and that pharmacological blockade of MORs in the SNr is more effective in reducing heroin reward than blockade of MORs in the VTA. Furthermore, optogenetic activation of VTA GABA neurons inhibited cocaine, but not heroin, self-administration, whereas activation of SNr GABA neurons inhibited heroin reward and relapse. These findings suggest that opioid reward is more likely mediated by stimulation of MORs in GABA afferents from other brain regions than in VTA GABA neurons.
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Affiliation(s)
- Ewa Galaj
- Addiction Biology Unit, Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse, Intramural Research Program, Baltimore, Maryland 21224
| | - Xiao Han
- Addiction Biology Unit, Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse, Intramural Research Program, Baltimore, Maryland 21224
| | - Hui Shen
- Synaptic Plasticity Section, National Institute on Drug Abuse, Intramural Research Program, Baltimore, Maryland 21224
| | - Chloe J Jordan
- Addiction Biology Unit, Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse, Intramural Research Program, Baltimore, Maryland 21224
| | - Yi He
- Addiction Biology Unit, Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse, Intramural Research Program, Baltimore, Maryland 21224
| | - Bree Humburg
- Addiction Biology Unit, Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse, Intramural Research Program, Baltimore, Maryland 21224
| | - Guo-Hua Bi
- Addiction Biology Unit, Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse, Intramural Research Program, Baltimore, Maryland 21224
| | - Zheng-Xiong Xi
- Addiction Biology Unit, Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse, Intramural Research Program, Baltimore, Maryland 21224
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Galaj E, Newman AH, Xi ZX. Dopamine D3 receptor-based medication development for the treatment of opioid use disorder: Rationale, progress, and challenges. Neurosci Biobehav Rev 2020; 114:38-52. [PMID: 32376243 PMCID: PMC7252042 DOI: 10.1016/j.neubiorev.2020.04.024] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 04/28/2020] [Indexed: 01/11/2023]
Abstract
Opioid abuse and related overdose deaths continue to rise in the United States, contributing to the current national opioid crisis. Although several opioid-based pharmacotherapies are available (e.g., methadone, buprenorphine, naloxone), they show limited effectiveness in long-term relapse prevention. In response to the opioid crisis, the National Institute on Drug Abuse proposed a list of pharmacological targets of highest priority for medication development for the treatment of opioid use disorders (OUD). Among these are antagonists of dopamine D3 receptors (D3R). In this review, we first review recent progress in research of the dopamine hypothesis of opioid reward and abuse and then describe the rationale and recent development of D3R ligands for the treatment of OUD. Herein, an emphasis is placed on the effectiveness of newly developed D3R antagonists in the animal models of OUD. These new drug candidates may also potentiate the analgesic effects of clinically used opioids, making them attractive as adjunctive medications for pain management and treatment of OUD.
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Affiliation(s)
- Ewa Galaj
- Molecular Targets and Medication Discovery Branch, National Institute on Drug Abuse, Intramural Research Program, Baltimore, MD, United States
| | - Amy Hauck Newman
- Molecular Targets and Medication Discovery Branch, National Institute on Drug Abuse, Intramural Research Program, Baltimore, MD, United States
| | - Zheng-Xiong Xi
- Molecular Targets and Medication Discovery Branch, National Institute on Drug Abuse, Intramural Research Program, Baltimore, MD, United States.
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6
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Spagnolo PA, Kimes A, Schwandt ML, Shokri-Kojori E, Thada S, Phillips KA, Diazgranados N, Preston KL, Herscovitch P, Tomasi D, Ramchandani VA, Heilig M. Striatal Dopamine Release in Response to Morphine: A [ 11C]Raclopride Positron Emission Tomography Study in Healthy Men. Biol Psychiatry 2019; 86:356-364. [PMID: 31097294 PMCID: PMC6699765 DOI: 10.1016/j.biopsych.2019.03.965] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 02/04/2019] [Accepted: 03/05/2019] [Indexed: 11/19/2022]
Abstract
BACKGROUND Preclinical and human positron emission tomography studies have produced inconsistent results regarding the effects of opioids on mesolimbic dopamine (DA). Here, we quantify striatal DA release (measured by [11C]raclopride displacement) in response to an intravenous infusion of morphine, and its relationship with morphine-induced subjective effects, in healthy, nondependent opioid-experienced participants. METHODS Fifteen healthy male participants were initially included. Sessions were on separate days. On session 1, participants received intravenous morphine (10 mg/70 kg) in the clinic to ensure tolerability. Participants without adverse reactions (n = 10) then received intravenous morphine and placebo (saline) sessions, in counterbalanced order, while undergoing [11C]raclopride positron emission tomography scans. Subjective and physiological responses were assessed. Region-of-interest and voxelwise image analyses were used to assess changes in [11C]raclopride nondisplaceable binding potential. RESULTS Morphine produced marked subjective and physiological effects and induced a significant decrease in [11C]raclopride nondisplaceable binding potential, particularly in the nucleus accumbens and globus pallidus, where the change in [11C]raclopride nondisplaceable binding potential was approximately 9%. However, the subjective effects of morphine did not show a simple pattern of correlation with DA release. CONCLUSIONS This is, to our knowledge, the first study providing in vivo human evidence that DA transmission in the ventral striatum is affected by morphine. Further studies are required to fully delineate the DA contribution to the reinforcing effects of opioids.
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Affiliation(s)
- Primavera A Spagnolo
- Human Motor Control Section, National Institute on Neurological Disorders and Stroke, National Instutes of Health, Bethesda, Maryland
| | - Alane Kimes
- Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, Maryland
| | - Melanie L Schwandt
- Office of the Clinical Director, National Institute on Alcohol Abuse and Alcoholism, National Instutes of Health, Bethesda, Maryland
| | - Ehsan Shokri-Kojori
- Laboratory of Neuroimaging, National Institute on Alcohol Abuse and Alcoholism, National Instutes of Health, Bethesda, Maryland
| | - Shantalaxmi Thada
- Positron Emission Tomography Department, Clinical Center, National Institute on Drug Abuse, National Institutes of Health, Baltimore, Maryland
| | - Karran A Phillips
- Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, Maryland
| | - Nancy Diazgranados
- Office of the Clinical Director, National Institute on Alcohol Abuse and Alcoholism, National Instutes of Health, Bethesda, Maryland
| | - Kenzie L Preston
- Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, Maryland
| | - Peter Herscovitch
- Positron Emission Tomography Department, Clinical Center, National Institute on Drug Abuse, National Institutes of Health, Baltimore, Maryland
| | - Dardo Tomasi
- Laboratory of Neuroimaging, National Institute on Alcohol Abuse and Alcoholism, National Instutes of Health, Bethesda, Maryland
| | - Vijay A Ramchandani
- Section on Human Psychopharmacology, National Institute on Alcohol Abuse and Alcoholism, National Instutes of Health, Bethesda, Maryland.
| | - Markus Heilig
- Center for Social and Affective Neuroscience, Linköping University, Linköping, Sweden.
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7
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Frontal cortex dysfunction as a target for remediation in opiate use disorder: Role in cognitive dysfunction and disordered reward systems. PROGRESS IN BRAIN RESEARCH 2018; 239:179-227. [DOI: 10.1016/bs.pbr.2018.07.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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8
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Porter-Stransky KA, Bentzley BS, Aston-Jones G. Individual differences in orexin-I receptor modulation of motivation for the opioid remifentanil. Addict Biol 2017; 22:303-317. [PMID: 26598295 DOI: 10.1111/adb.12323] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Revised: 08/29/2015] [Accepted: 09/30/2015] [Indexed: 01/18/2023]
Abstract
Orexin-1 receptors (Ox1Rs) have been implicated in the motivation for drugs of abuse. Here, we utilized a within-session behavioral-economics threshold procedure to screen for individual differences in economic demand for the ultra-short-acting opioid remifentanil and to test whether antagonism of Ox1Rs reduces remifentanil demand. The behavioral-economics procedure revealed robust individual differences in free consumption of remifentanil (Q0 parameter; hedonic set point). Rats with low baseline Q0 (low takers) displayed high demand elasticity (α parameter; reduced responding as drug price increased indicating low motivation for drug), whereas subjects with a higher Q0 (high takers) exhibit low demand elasticity (low α) by continuing to self-administer remifentanil despite increased cost (reflecting higher motivation for drug). In a punished responding paradigm utilizing footshock, subjects that were classified as high takers at baseline withstood twice as much shock as low takers to continue self-administering remifentanil. Interestingly, Ox1R antagonism with SB-334867 reduced Q0 and increased α in low takers but not in high takers. Similarly, the Ox1R antagonist attenuated cue-induced, but not drug-induced, reinstatement of remifentanil seeking in low takers but had no significant effect on reinstatement of drug seeking in high takers. Together, these data reveal a novel role of orexins in demand for remifentanil: Ox1Rs modulate demand in low takers but not in individuals that exhibit addictive-like behaviors (high takers). Finally, the behavioral assays in this study can serve as a novel laboratory model for studying individual differences in opioid use disorders.
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Affiliation(s)
| | - Brandon S. Bentzley
- Department of Neurosciences; Medical University of South Carolina; Charleston SC USA
| | - Gary Aston-Jones
- Department of Neurosciences; Medical University of South Carolina; Charleston SC USA
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9
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Ellenbroek BA. Histamine H₃ receptors, the complex interaction with dopamine and its implications for addiction. Br J Pharmacol 2014; 170:46-57. [PMID: 23647606 DOI: 10.1111/bph.12221] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Revised: 04/10/2013] [Accepted: 04/18/2013] [Indexed: 01/08/2023] Open
Abstract
Histamine H₃ receptors are best known as presynaptic receptors inhibiting the release of histamine, as well as other neurotransmitters including acetylcholine and dopamine. However, in the dorsal and ventral striatum, the vast majority of H₃ receptors are actually located postsynaptically on medium sized spiny output neurons. These cells also contain large numbers of dopamine (D₁ and D₂) receptors and it has been shown that H₃ receptors form heterodimers with both D₁ and D₂ receptors. Thus, the anatomical localization of H₃ receptors suggests a complex interaction that could both enhance and inhibit dopaminergic neurotransmission. Dopamine, especially within the striatal complex, plays a crucial role in the development of addiction, both in the initial reinforcing effects of drugs of abuse, as well as in maintenance, relapse and reinstatement of drug taking behaviour. It is, therefore, conceivable that H₃ receptors can moderate the development and maintenance of drug addiction. In the present review, we appraise the current literature on the involvement of H₃ receptors in drug addiction and try to explain these data within a theoretical framework, as well as provide suggestions for further research.
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Affiliation(s)
- B A Ellenbroek
- School of Psychology, Victoria University, Wellington, New Zealand.
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10
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Abstract
Drug addiction is a chronic relapsing disorder for which research has been dedicated to understand the various factors that contribute to development, loss of control, and persistence of compulsive addictive behaviors. In this review, we provide a broad overview of various theories of addiction, drugs of abuse, and the neurobiology involved across the addiction cycle. Specific focus is devoted to the role of the mesolimbic pathway in acute drug reinforcement and occasional drug use, the mesocortical pathway and associated areas (e.g., the dorsal striatum) in escalation/dependence, and the involvement of these pathways and associated circuits in mediating conditioned responses, drug craving, and loss of behavioral control thought to underlie withdrawal and relapse. With a better understanding of the neurobiological factors that underlie drug addiction, continued preclinical and clinical research will aid in the development of novel therapeutic interventions that can serve as effective long-term treatment strategies for drug-dependent individuals.
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Affiliation(s)
- Matthew W Feltenstein
- Department of Neurosciences, Medical University of South Carolina, Charleston, SC 29425, USA
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11
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Gao J, Li Y, Zhu N, Brimijoin S, Sui N. Roles of dopaminergic innervation of nucleus accumbens shell and dorsolateral caudate-putamen in cue-induced morphine seeking after prolonged abstinence and the underlying D1- and D2-like receptor mechanisms in rats. J Psychopharmacol 2013; 27:181-91. [PMID: 23151613 PMCID: PMC3746592 DOI: 10.1177/0269881112466181] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Drug-associated cues can elicit relapse to drug seeking after abstinence. Studies with extinction-reinstatement models implicate dopamine (DA) in the nucleus accumbens shell (NAshell) and dorsolateral caudate-putamen (dlCPu) in cocaine seeking. However, less is known about their roles in cue-induced opiate seeking after prolonged abstinence. Using a morphine self-administration and abstinence-relapse model, we explored the roles of NAshell and dlCPu DA and the D1/D2-like receptor mechanisms underlying morphine rewarding and/or seeking. Acquisition of morphine self-administration was examined following 6-Hydroxydopamine hydrobromide (6-OHDA) lesions of the NAshell and dlCPu. For morphine seeking, rats underwent 3 weeks' morphine self-administration followed by 3 weeks' abstinence from morphine and the training environment. Prior to testing, 6-OHDA, D1 antagonist SCH23390, or D2 antagonist eticlopride was locally injected; then rats were exposed to morphine-associated contextual and discrete cues. Results show that acquisition of morphine self-administration was inhibited by NAshell (not dlCPu) lesions, while morphine seeking was attenuated by lesions of either region, by D1 (not D2) receptor blockade in NAshell, or by blockade of either D1 or D2 receptors in dlCPu. These data indicate a critical role of dopaminergic transmission in the NAshell (via D1-like receptors) and dlCPu (via D1- and D2-like receptors) in morphine seeking after prolonged abstinence.
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Affiliation(s)
- Jun Gao
- Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China,Graduate University of Chinese Academy of Sciences, Beijing, China
| | - Yonghui Li
- Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
| | - Ning Zhu
- Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
| | - Stephen Brimijoin
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, USA
| | - Nan Sui
- Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
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Puglisi-Allegra S, Ventura R. Prefrontal/accumbal catecholamine system processes high motivational salience. Front Behav Neurosci 2012; 6:31. [PMID: 22754514 PMCID: PMC3384081 DOI: 10.3389/fnbeh.2012.00031] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Accepted: 06/02/2012] [Indexed: 12/24/2022] Open
Abstract
Motivational salience regulates the strength of goal seeking, the amount of risk taken, and the energy invested from mild to extreme. Highly motivational experiences promote highly persistent memories. Although this phenomenon is adaptive in normal conditions, experiences with extremely high levels of motivational salience can promote development of memories that can be re-experienced intrusively for long time resulting in maladaptive outcomes. Neural mechanisms mediating motivational salience attribution are, therefore, very important for individual and species survival and for well-being. However, these neural mechanisms could be implicated in attribution of abnormal motivational salience to different stimuli leading to maladaptive compulsive seeking or avoidance. We have offered the first evidence that prefrontal cortical norepinephrine (NE) transmission is a necessary condition for motivational salience attribution to highly salient stimuli, through modulation of dopamine (DA) in the nucleus accumbens (NAc), a brain area involved in all motivated behaviors. Moreover, we have shown that prefrontal-accumbal catecholamine (CA) system determines approach or avoidance responses to both reward- and aversion-related stimuli only when the salience of the unconditioned stimulus (UCS) is high enough to induce sustained CA activation, thus affirming that this system processes motivational salience attribution selectively to highly salient events.
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Affiliation(s)
- Stefano Puglisi-Allegra
- Dipartimento di Psicologia and Centro "Daniel Bovet", "Sapienza" University of Rome Rome, Italy
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13
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Badiani A, Belin D, Epstein D, Calu D, Shaham Y. Opiate versus psychostimulant addiction: the differences do matter. Nat Rev Neurosci 2011; 12:685-700. [PMID: 21971065 DOI: 10.1038/nrn3104] [Citation(s) in RCA: 355] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The publication of the psychomotor stimulant theory of addiction in 1987 and the finding that addictive drugs increase dopamine concentrations in the rat mesolimbic system in 1988 have led to a predominance of psychobiological theories that consider addiction to opiates and addiction to psychostimulants as essentially identical phenomena. Indeed, current theories of addiction - hedonic allostasis, incentive sensitization, aberrant learning and frontostriatal dysfunction - all argue for a unitary account of drug addiction. This view is challenged by behavioural, cognitive and neurobiological findings in laboratory animals and humans. Here, we argue that opiate addiction and psychostimulant addiction are behaviourally and neurobiologically distinct and that the differences have important implications for addiction treatment, addiction theories and future research.
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Affiliation(s)
- Aldo Badiani
- Department of Physiology and Pharmacology Vittorio Erspamer, Sapienza University of Rome, Rome, Italy.
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Wang Y, Zhang F, Tang S, Lai M, Hao W, Zhang Y, Yang J, Zhou W. Lack of effect of habenula lesion on heroin self-administration in rats. Neurosci Lett 2009; 461:167-71. [PMID: 19539705 DOI: 10.1016/j.neulet.2009.06.029] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2009] [Revised: 05/25/2009] [Accepted: 06/02/2009] [Indexed: 12/01/2022]
Abstract
We examined the effects of bilateral electric lesion of the habenula (Hb) on the acquisition and maintenance of heroin self-administration. The rats were trained to self-administer heroin (0.05 mg/kg/infusion) under FR1 schedule in daily 4h sessions. A progressive ratio schedule (PR3-4) was used to evaluate the relative motivational value of heroin reinforcement. Compared with the controls, neither pre-training nor post-training of Hb lesions had any effects on the total amount of infusions and motivational value of heroin reward. However, pre-training Hb lesion caused transient active and inactive nose-poke responding in the early phase of training, suggesting increased locomotor exploration. The results suggest that Hb might not play an important role in mediating the acute reinforcing effect of heroin.
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Affiliation(s)
- Yuhong Wang
- Mental Health Institute and WHO Collaborating Center for Drug Abuse and Health, The 2nd Xiangya Affiliated Hospital, Central South University, Changsha, China
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15
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Operant sensation seeking engages similar neural substrates to operant drug seeking in C57 mice. Neuropsychopharmacology 2009; 34:1685-94. [PMID: 19145223 PMCID: PMC2720253 DOI: 10.1038/npp.2008.226] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Novelty and sensation seeking have been associated with elevated drug intake in human and animal studies, suggesting overlap in the circuitry mediating these behaviors. In this study, we found that C57Bl/6J mice readily acquired operant responding for dynamic visual stimuli, a phenomenon we term operant sensation seeking (OSS). Like operant studies using other reinforcers, mice responded on fixed and progressive ratio schedules, were resistant to extinction, and had sustained responding with extended access. We also found that OSS, like psychostimulant self-administration, is sensitive to disruption of dopamine signaling. Low doses of the dopamine antagonist cis-flupenthixol increased active lever responding, an effect reported for psychostimulant self-administration. Additionally, D1-deficient mice failed to acquire OSS, although they readily acquired lever pressing for food. Finally, we found that one common measure of novelty seeking, locomotor activity in a novel open field, did not predict OSS performance. OSS may have predictive validity for screening compounds for use in the treatment of drug addiction. In addition, we also discuss the potential relevance of this animal model to the field of behavioral addictions.
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Celentano M, Caprioli D, Dipasquale P, Cardillo V, Nencini P, Gaetani S, Badiani A, Badiani A. Drug context differently regulates cocaine versus heroin self-administration and cocaine- versus heroin-induced Fos mRNA expression in the rat. Psychopharmacology (Berl) 2009; 204:349-60. [PMID: 19169671 DOI: 10.1007/s00213-009-1467-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2008] [Accepted: 01/05/2009] [Indexed: 11/24/2022]
Abstract
RATIONALE We have previously reported that cocaine self-administration is facilitated in male rats not residing in the test chambers (Non Resident rats) relative to rats living in the test chambers at all times (Resident rats). Surprisingly, the opposite was found for heroin. MATERIALS AND METHODS We predicted that, when given access to both cocaine and heroin on alternate days, Non Resident rats would take more cocaine relative to heroin than Resident rats. Heroin (25.0 microg/kg) and cocaine (400 microg/kg), were made alternately available for 14 self-administration sessions, on a fixed ratio (FR) schedule that was progressively increased from FR1 to FR5. Next, some rats underwent a progressive-ratio procedure for heroin and cocaine. The other rats continued to alternate heroin and cocaine self-administration for 12 additional sessions, during which the FR schedule was progressively increased from FR10 to FR100. The second aim of the study was to investigate Fos mRNA expression in Resident and Non Resident rats treated with non-contingent intravenous infusion of "self-administration doses" of heroin (25.0 microg/kg) and cocaine (400 microg/kg). RESULTS We found that: (1) drug-taking context differentially modulates intravenous cocaine versus heroin self-administration; (2) very low doses of cocaine and heroin are sufficient to induce Fos mRNA expression in the posterior caudate; (3) drug-administration context differentially modulates cocaine- versus heroin-induced Fos mRNA expression. CONCLUSIONS Our study indicates that the context of drug taking can play a powerful role in modulating cocaine versus heroin intake in the laboratory rat.
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Affiliation(s)
- Michele Celentano
- Department of Physiology and Pharmacology Vittorio Erspamer, Sapienza University of Rome, Rome, Italy
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Koob GF. Dynamics of neuronal circuits in addiction: reward, antireward, and emotional memory. PHARMACOPSYCHIATRY 2009; 42 Suppl 1:S32-41. [PMID: 19434554 PMCID: PMC2739305 DOI: 10.1055/s-0029-1216356] [Citation(s) in RCA: 160] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Drug addiction is conceptualized as chronic, relapsing compulsive use of drugs with significant dysregulation of brain hedonic systems. Compulsive drug use is accompanied by decreased function of brain substrates for drug positive reinforcement and recruitment of brain substrates mediating the negative reinforcement of motivational withdrawal. The neural substrates for motivational withdrawal ("dark side" of addiction) involve recruitment of elements of the extended amygdala and the brain stress systems, including corticotropin-releasing factor and norepinephrine. These changes, combined with decreased reward function, are hypothesized to persist in the form of an allostatic state that forms a powerful motivational background for relapse. Relapse also involves a key role for the basolateral amygdala in mediating the motivational effects of stimuli previously paired with drug seeking and drug motivational withdrawal. The basolateral amygdala has a key role in mediating emotional memories in general. The hypothesis argued here is that brain stress systems activated by the motivational consequences of drug withdrawal can not only form the basis for negative reinforcement that drives drug seeking, but also potentiate associative mechanisms that perpetuate the emotional state and help drive the allostatic state of addiction.
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Affiliation(s)
- G F Koob
- Committee on the Neurobiology of Addictive Disorders, The Scripps Research Institute, La Jolla, California 92037, USA.
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18
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Mickiewicz AL, Dallimore JE, Napier TC. The ventral pallidum is critically involved in the development and expression of morphine-induced sensitization. Neuropsychopharmacology 2009; 34:874-86. [PMID: 18668032 DOI: 10.1038/npp.2008.111] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Repeated, intermittent exposure to drugs of abuse results in response enhancements to subsequent drug treatments, a phenomenon referred to as sensitization. As persistent neuronal sensitization may contribute to the long-lasting consequences of drug abuse, characterizing the neuroanatomical substrates of sensitization is providing insights into addiction. It is known that the ventral tegmental area (VTA) is necessary for induction, and expression involves the nucleus accumbens (NAc). We reveal here that the ventral pallidum (VP), a brain region reciprocally innervated by the VTA and the NAc, is a critical mediator of opiate-induced behavioral sensitization. Blockade of VP mu-opioid receptors (via intra-VP CTOP injections) negated the ability of systemic administration of the opiate, morphine to induce motor sensitization, and for sensitized rats to subsequently express enhanced responding to a morphine challenge. Intra-VP morphine was sufficient to induce motor sensitization, and this sensitization was expressed following 17 days of withdrawal. Rats with a treatment history of intra-VP morphine demonstrated cross-sensitization to a challenge injection of systemically administered morphine. Conversely, repeated systemic treatments of morphine cross-sensitized to an intra-VP morphine challenge. These results indicate that activation of VP mu-opioid receptors is sufficient to evoke behavioral sensitization and that these receptors are necessary for sensitized responding to systemic morphine. The study pioneers the concept that both development and expression of drug-induced sensitization are regulated by the VP. Thus, the VP is likely an important contributor to neuronal adaptations that underlie addiction.
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Affiliation(s)
- Amanda L Mickiewicz
- Department of Pharmacology and Experimental Therapeutics, Stritch School of Medicine, Loyola University Chicago, Maywood, IL, USA.
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19
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Abstract
Drug addiction presents as a chronic relapsing disorder characterized by persistent drug-seeking and drug-taking behaviours. Given the significant detrimental effects of this disease both socially and economically, a considerable amount of research has been dedicated to understanding a number of issues in addiction, including behavioural and neuropharmacological factors that contribute to the development, loss of control and persistence of compulsive addictive behaviours. In this review, we will give a broad overview of various theories of addiction, animal models of addiction and relapse, drugs of abuse, and the neurobiology of drug dependence and relapse. Although drugs of abuse possess diverse neuropharmacological profiles, activation of the mesocorticolimbic system, particularly the ventral tegmental area, nucleus accumbens, amygdala and prefrontal cortex via dopaminergic and glutamatergic pathways, constitutes a common pathway by which various drugs of abuse mediate their acute reinforcing effects. However, long-term neuroadaptations in this circuitry likely underlie the transition to drug dependence and cycles of relapse. As further elucidated in more comprehensive reviews of various subtopics on addiction in later sections of this special issue, it is anticipated that continued basic neuroscience research will aid in the development of effective therapeutic interventions for the long-term treatment of drug-dependent individuals.
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Affiliation(s)
- M W Feltenstein
- Department of Neurosciences, Medical Universiy of South Carolina, Charleston, SC 29425, USA.
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20
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Abstract
Fueled by anatomical, electrophysiological, and pharmacological analyses of endogenous brain reward systems, norepinephrine (NE) was identified as a key mediator of both natural and drug-induced reward in the late 1960s and early 1970s. However, reward experiments from the mid-1970s that could distinguish between the noradrenergic and dopaminergic systems resulted in the prevailing view that dopamine (DA) was the primary 'reward transmitter' (a belief holding some sway still today), thereby pushing NE into the background. Most damaging to the NE hypothesis of reward were studies demonstrating that NE receptor antagonists and NE reuptake inhibitors failed to impact drug self-administration. In recent years new tools, such as genetically engineered mice, and new experimental paradigms, such as reinstatement of drug seeking following withdrawal, have propelled NE back into the awareness of addiction researchers. Of particular interest is disulfiram, an inhibitor of the NE biosynthetic enzyme dopamine beta-hydroxylase, which has demonstrated promising efficacy in the treatment of cocaine dependence in preliminary clinical trials. The purpose of this review is to synthesize the new data linking NE to critical aspects of DA signaling and drug addiction, with a focus on psychostimulants (eg, cocaine), opiates (eg, morphine), and alcohol.
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Affiliation(s)
- David Weinshenker
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322, USA.
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Frenois F, Le Moine C, Cador M. The motivational component of withdrawal in opiate addiction: role of associative learning and aversive memory in opiate addiction from a behavioral, anatomical and functional perspective. Rev Neurosci 2006; 16:255-76. [PMID: 16323564 DOI: 10.1515/revneuro.2005.16.3.255] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
A major challenge in current drug addiction research is not only to understand the immediate effects of drugs of abuse on brain operations, but also to define at the behavioral and neural levels how cognitive, emotional and motivational processes interact with drug use in order to lead to this psychopathological state which defines addiction. It is now clear that factors other than the direct effects of drugs of abuse are able to powerfully affect drug-seeking and drug-taking behaviors. In former opiate addicts, re-exposure to environmental situations previously paired with withdrawal is able to induce strong craving episodes. It has been proposed that these conditioned stimuli could be strongly involved in precipitating relapse in drug-taking behavior by re-activating the neurobiological circuits which are engaged in an unconditioned way by the withdrawal state itself, leading to a powerful aversive state relieved by drug consumption renewal. In the present review, we provide evidence from a neuropsychopharmacological viewpoint that environmental situations previously paired with the opiate withdrawal syndrome might be able to maintain drug-seeking motivation. Using behavioral models which allow assessment of the aversive and motivational properties of opiate withdrawal both in the unconditioned and conditioned situations, we have recently investigated using extensive mapping the neurobiological correlates which underlie acute withdrawal and the trace of its memory in the brain in terms of localization and neuronal population involved, with an anatomical and functional approach. Thus, on the basis of our results, and together with a number of data in the literature, we provide a functional model for the formation and retrieval of opiate withdrawal memories.
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Affiliation(s)
- François Frenois
- Interactions Neuronales et Comportements, Université Victor Segalen, Bordeaux, France.
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22
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Pierce RC, Kumaresan V. The mesolimbic dopamine system: the final common pathway for the reinforcing effect of drugs of abuse? Neurosci Biobehav Rev 2005; 30:215-38. [PMID: 16099045 DOI: 10.1016/j.neubiorev.2005.04.016] [Citation(s) in RCA: 590] [Impact Index Per Article: 31.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2005] [Revised: 04/05/2005] [Accepted: 04/19/2005] [Indexed: 11/23/2022]
Abstract
In this review we will critically assess the hypothesis that the reinforcing effect of virtually all drugs of abuse is primarily dependent on activation of the mesolimbic dopamine system. The focus is on five classes of abused drugs: psychostimulants, opiates, ethanol, cannabinoids and nicotine. For each of these drug classes, the pharmacological and physiological mechanisms underlying the direct or indirect influence on mesolimbic dopamine transmission will be reviewed. Next, we evaluate behavioral pharmacological experiments that specifically assess the influence of activation of the mesolimbic dopamine system on drug reinforcement, with particular emphasis on animal experiments using drug self-administration paradigms. There is overwhelming evidence that all five classes of abused drugs increase dopamine transmission in limbic regions of the brain through interactions with a variety of transporters, ionotropic receptors and metabotropic receptors. Behavioral pharmacological experiments indicate that increased dopamine transmission is clearly both necessary and sufficient to promote psychostimulant reinforcement. For the other four classes of abused substances, self-administration experiments suggest that although increasing mesolimbic dopamine transmission plays an important role in the reinforcing effects of opiates, ethanol, cannabinoids and nicotine, there are also dopamine-independent processes that contribute significantly to the reinforcing effects of these compounds.
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Affiliation(s)
- R Christopher Pierce
- Department of Pharmacology, Boston University School of Medicine, 715 Albany Street, L603 Boston, MA 02118, USA.
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23
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Cornish JL, Lontos JM, Clemens KJ, McGregor IS. Cocaine and heroin ('speedball') self-administration: the involvement of nucleus accumbens dopamine and mu-opiate, but not delta-opiate receptors. Psychopharmacology (Berl) 2005; 180:21-32. [PMID: 15682301 DOI: 10.1007/s00213-004-2135-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2004] [Accepted: 11/22/2004] [Indexed: 10/25/2022]
Abstract
RATIONALE The combined administration of heroin and cocaine ('speedball') is common among intravenous drug users. Dopamine receptors in the nucleus accumbens play a key role in cocaine self-administration; however, their role in speedball self-administration is unknown, as is the role of opiate receptors in this region. OBJECTIVES The effect of blocking dopamine D1, D2, mu-opiate or delta-opiate receptors in the nucleus accumbens on the intravenous self-administration of combined heroin and cocaine was examined in rats. METHODS Rats with bilateral cannulae implanted into the nucleus accumbens were trained to self-administer intravenous speedball (ratio of cocaine/heroin, 17:1) under a progressive ratio (PR) schedule. Prior to their self-administration session, rats were then microinjected with the dopamine D1 receptor antagonist SCH 23390 (1 and 6 nmol side(-1)), the D2 receptor antagonist raclopride (3 and 10 nmol side(-1)), the mu-opiate receptor antagonist CTOP (0.1, 0.3 and 1.0 nmol side(-1)), the delta-opiate receptor antagonist naltrindole (1.0, 3.0 and 10 nmol side(-1)) or a cocktail of SCH 23390 (1 nmol side(-1)) and CTOP (0.1 nmol side(-1)) into the nucleus accumbens. RESULTS Microinjection of SCH 23390, raclopride or CTOP into the nucleus accumbens produced dose-dependent decreases in breakpoints under the PR schedule, while naltrindole was without effect. The highest dose of SCH 23390 also significantly reduced locomotor activity measured during speedball self-administration. The combination of SCH 23390 and CTOP significantly reduced breakpoints, while not affecting locomotor activity. CONCLUSIONS These results indicate that dopamine and mu-opiate receptors, but not delta-opiate receptors, in the nucleus accumbens are involved in the reinforcing effects of speedball. Combined administration of D1 and mu-opiate receptor antagonists may be more selective at reducing the reinforcing effects of speedball self-administration than either drug alone.
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MESH Headings
- Animals
- Cocaine/administration & dosage
- Cocaine/pharmacology
- Dose-Response Relationship, Drug
- Drug Interactions
- Heroin/administration & dosage
- Heroin/pharmacology
- Male
- Nucleus Accumbens/drug effects
- Nucleus Accumbens/metabolism
- Rats
- Receptors, Dopamine/physiology
- Receptors, Dopamine D1/physiology
- Receptors, Dopamine D2/physiology
- Receptors, Opioid/physiology
- Receptors, Opioid, mu/physiology
- Receptors, sigma/physiology
- Reinforcement Schedule
- Self Administration
- Substance Abuse, Intravenous/metabolism
- Substance Abuse, Intravenous/physiopathology
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24
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Chapter VI Dopamine, motivation and reward. ACTA ACUST UNITED AC 2005. [DOI: 10.1016/s0924-8196(05)80010-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
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25
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Narayanan S, Lam H, Christian L, Levine MS, Grandy D, Rubinstein M, Maidment NT. Endogenous opioids mediate basal hedonic tone independent of dopamine D-1 or D-2 receptor activation. Neuroscience 2004; 124:241-6. [PMID: 14960355 DOI: 10.1016/j.neuroscience.2003.11.011] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/13/2003] [Indexed: 10/26/2022]
Abstract
Exogenously administered opiates are recognized as rewarding and the involvement of dopamine systems in mediating their apparent pleasurable effects is contentious. The aversive response to naloxone administration observed in animal studies suggests the presence of an endogenous opioid tone regulating hedonic state. We sought evidence for the requirement for dopamine systems in mediating this action of endogenous opioids by determining whether mice deficient in dopamine D-1 or D-2 receptors were able to display conditioned place aversion to naloxone. Mice received saline in the morning in one chamber and either saline or naloxone (10 mg/kg, s.c.) in the afternoon in another chamber, each day for 3 days. On the test day they were given free access to the testing chambers in the afternoon. Similar to their wild-type littermates, D-1 and D-2 receptor knockout mice receiving naloxone in the afternoon spent significantly less time on the test day in the compartment in which they previously received naloxone, compared with animals receiving saline in the afternoon. The persistence of naloxone-conditioned place aversion in D-1 and D-2 knockout mice suggests that endogenous opioid peptides maintain a basal level of positive affect that is not dependent on downstream activation of dopamine systems involving D-1 or D-2 receptors.
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Affiliation(s)
- S Narayanan
- Department of Psychiatry and Biobehavioral Sciences, University of California at Los Angeles Neuropsychiatric Institute, 760 Westwood Plaza, Los Angeles, CA 90024, USA
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26
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Zheng F, Johnson SW. Dual modulation of gabaergic transmission by metabotropic glutamate receptors in rat ventral tegmental area. Neuroscience 2003; 119:453-60. [PMID: 12770559 DOI: 10.1016/s0306-4522(03)00190-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The effects of metabotropic glutamate receptor (mGluR) activation on non-dopamine (putative GABAergic) neurons and inhibitory synaptic transmission in the ventral tegmental area were examined using intracellular recordings from rat midbrain slices. Perfusion of (+/-)-1-aminocyclopentane-trans-1,3-dicarboxylic acid (t-ACPD; agonist for group I and II mGluRs), but not L-amino-4-phosphonobutyric acid (L-AP4; agonist for group III mGluRs), produced membrane depolarization (current clamp) and inward current (voltage clamp) in non-dopamine neurons. The t-ACPD-induced depolarization was concentration-dependent (concentration producing 50% maximal depolarization [EC(50)]=6.1+/-2.5 microM), and was blocked by the antagonist (+/-)-alpha-methyl-4-carboxyphenylglycine, but not by tetrodotoxin and ionotropic glutamate-receptor antagonists. The t-ACPD-evoked responses were mimicked comparably by selective group I mGluR agonist (RS)-3,5-dihydroxyphenylglycine (DHPG). Furthermore, the DHPG-induced depolarization in non-dopamine neurons was greatly reduced by mGluR1-specific antagonist 7(hydroxyimino)cyclopropachromen-1a-carboxylate ethyl ester. When recorded in dopamine neurons, the frequency of spontaneous GABA(A) receptor-mediated inhibitory postsynaptic potentials was increased by t-ACPD but not L-AP4. However, the amplitude of evoked inhibitory postsynaptic currents in dopamine neurons was reduced by all three group mGluR agonists. These results reveal a dual modulation of mGLuR activation on inhibitory transmission in midbrain ventral tegmental area: enhancing putative GABAergic neuronal excitability and thus potentiating tonic inhibitory synaptic transmission while reducing evoked synaptic transmission at inhibitory terminals.
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Affiliation(s)
- F Zheng
- Department of Neurology, Oregon Health and Science University, Portland, OR 97239, USA
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27
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Skoubis PD, Maidment NT. Blockade of ventral pallidal opioid receptors induces a conditioned place aversion and attenuates acquisition of cocaine place preference in the rat. Neuroscience 2003; 119:241-9. [PMID: 12763085 DOI: 10.1016/s0306-4522(03)00121-0] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Peripheral administration of naloxone is known to produce a conditioned place aversion and to block cocaine-induced conditioned place preference. The ventral pallidum receives a dense enkephalinergic projection from the nucleus accumbens and is implicated as a locus mediating the rewarding and reinforcing effects of psychostimulant and opiate drugs. We sought to provide evidence for the involvement of pallidal opioid receptors in modulating affective state using the place-conditioning paradigm. Microinjection of naloxone (0.01-10 microg) into the ventral pallidum once a day for 3 days dose-dependently produced a conditioned place aversion when tested in the drug-free state 24 h after the last naloxone injection. This effect was reproduced using the mu-opioid receptor selective agonist D-Phe-Cys-Tyr-D-Trp-Orn-Thr-Pen-Thr-NH(2) (CTOP, 1 microg). Locomotor activity was reduced following injection of the highest dose of naloxone (10 microg) but elevated following CTOP (1 microg). Daily injection of cocaine (10 mg/kg) for 3 days produced a conditioned place preference 24 h later. This effect of cocaine was attenuated by concomitant intra-ventral pallidal injection of naloxone at a dose (0.01 microg) that had no significant aversive property when injected alone. In contrast, the locomotor activation induced by peripheral cocaine injection was unaffected by naloxone injection into the ventral pallidum. The data implicate endogenous opioid peptide systems within the ventral pallidum as regulators of hedonic status.
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Affiliation(s)
- P D Skoubis
- Department of Psychiatry and Biobehavioral Sciences, Neuropsychiatric Institute, University of California at Los Angeles, 760 Westwood Plaza, Los Angeles, CA 90024, USA
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28
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Smith JE, Koves TR, Co C. Brain neurotransmitter turnover rates during rat intravenous cocaine self-administration. Neuroscience 2003; 117:461-75. [PMID: 12614686 DOI: 10.1016/s0306-4522(02)00819-9] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The turnover rates of dopamine, norepinephrine, serotonin, aspartate, glutamate and GABA were measured in 27 brain regions of rats self-administering cocaine and in yoked cocaine- and yoked vehicle-infused controls using radioactive pulse-labeling procedures to identify brain neuronal systems underlying self-administration. Changes in the activity of heretofore unrecognized dopamine, norepinephrine, serotonin, glutamate and GABA innervations of the forebrain specific to cocaine self-administration were found. This included innervations of the nucleus accumbens, ventral pallidum, lateral hypothalamus and the anterior and posterior cingulate, entorhinal-subicular and visual cortices. Turnover rates also were calculated using metabolite/neurotransmitter ratios which were inconsistent with the pulse-label technologies indicating that ratio procedures are not accurate measures of neurotransmitter utilization. Results with the pulse-label technique provide evidence of the involvement of neuronal systems in cocaine self-administration not previously known, some of which may have a broader role in brain reinforcement processes for natural reinforcers (i.e. food, water, etc.) since drugs of abuse are thought to produce reinforcing effects by modulating activity in these endogenous systems.
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Affiliation(s)
- J E Smith
- Center for the Neurobiological Investigation of Drug Abuse, Department of Physiology and Pharmacology, Wake Forest University School of Medicine, Wake Forest University, Medical Center Boulevard, Winston-Salem, NC 27157-1083, USA.
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Salamone JD, Correa M. Motivational views of reinforcement: implications for understanding the behavioral functions of nucleus accumbens dopamine. Behav Brain Res 2002; 137:3-25. [PMID: 12445713 DOI: 10.1016/s0166-4328(02)00282-6] [Citation(s) in RCA: 555] [Impact Index Per Article: 25.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Although the Skinnerian 'Empirical Law of Effect' does not directly consider the fundamental properties of stimuli that enable them to act as reinforcers, such considerations are critical for determining if nucleus accumbens dopamine systems mediate reinforcement processes. Researchers who have attempted to identify the critical characteristics of reinforcing stimuli or activities have generally arrived at an emphasis upon motivational factors. A thorough review of the behavioral literature indicates that, across several different investigators offering a multitude of theoretical approaches, motivation is seen by many as being fundamental to the process of reinforcement. The reinforcer has been described as a goal, a commodity, an incentive, or a stimulus that is being approached, self-administered, attained or preserved. Reinforcers also have been described as activities that are preferred, deprived or in some way being regulated. It is evident that this 'motivational' or 'regulatory' view of reinforcement has had enormous influence over the hypothesis that DA directly mediates 'reward' or 'reinforcement' processes. Indeed, proponents of the DA/reward hypothesis regularly cite motivational theorists and employ their language. Nevertheless, considerable evidence indicates that low/moderate doses of DA antagonists, and depletions of DA in nucleus accumbens, can suppress instrumental responding for food while, at the same time, these conditions leave fundamental aspects of reinforcement (i.e. primary or unconditioned reinforcement; primary motivation or primary incentive properties of natural reinforcers) intact. Several complex features of the literature on dopaminergic involvement in reinforcement are examined below, and it is argued that the assertions that DA mediates 'reward' or 'reinforcement' are inaccurate and grossly oversimplified. Thus, it appears as though it is no longer tenable to assert that drugs of abuse are simply turning on the brain's natural 'reward system'. In relation to the hypothesis that DA systems are involved in 'wanting', but not 'liking', it is suggested in the present review that 'wanting' has both directional aspects (e.g. appetite to consume food) and activational aspects (e.g. activation for initiating and sustaining instrumental actions; tendency to work for food). The present paper reviews findings in support of the hypothesis that low doses of DA antagonists and accumbens DA depletions do not impair appetite to consume food, but do impair activational aspects of motivation. This suggestion is consistent with the studies showing that low doses of DA antagonists and accumbens DA depletions alter the relative allocation of instrumental responses, making the animals less likely to engage in instrumental responses that have a high degree of work-related response costs. In addition, this observation is consistent with studies demonstrating that accumbens DA depletions make rats highly sensitive to ratio requirements on operant schedules. Although accumbens DA is not seen as directly mediating appetite to consume food, principles of behavioral economics indicate that accumbens DA could be involved in the elasticity of demand for food in terms of the tendency to pay work-related response costs. Future research must focus upon how specific aspects of task requirements (i.e. ratio requirements, intermittence of reinforcement, temporal features of response requirements, dependence upon conditioned stimuli) interact with the effects of accumbens DA depletions, and which particular factors determine sensitivity to the effects of DA antagonism or depletion.
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Affiliation(s)
- John D Salamone
- Department of Psychology, University of Connecticut, Storrs, CT 06269-1020, USA.
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30
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Abstract
There is substantial evidence that dopamine is involved in reward learning and appetitive conditioning. However, the major reinforcement learning-based theoretical models of classical conditioning (crudely, prediction learning) are actually based on rules designed to explain instrumental conditioning (action learning). Extensive anatomical, pharmacological, and psychological data, particularly concerning the impact of motivational manipulations, show that these models are unreasonable. We review the data and consider the involvement of a rich collection of different neural systems in various aspects of these forms of conditioning. Dopamine plays a pivotal, but complicated, role.
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Affiliation(s)
- Peter Dayan
- Gatsby Computational Neuroscience Unit, University College London, 17 Queen Square, WC1N 3AR, London, United Kingdom.
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31
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Abstract
The effects of morphine on extracellular dopamine levels in brain have never been studied over a wide range of doses within a single study. This has made it difficult to make definitive interpretations of drug interactions with morphine. An inhibition of morphine-induced increases in dopamine could be interpreted as either antagonism or potentiation depending the shape of the morphine dose-response curve. Accordingly, the aim of the present study was to determine the effects of a wide range of morphine doses (0, 5, 10, 20 and 30 mg/kg, i.p.) on extracellular dopamine, DOPAC and HVA levels in the nucleus accumbens and striatum of awake and freely moving female Sprague-Dawley rats. The results show that, in both brain regions, the dose-response curve for morphine-induced increases in dopamine is non-monotonic while the dose-response curve for morphine-induced increases in DOPAC and HVA is monotonic in the nucleus accumbens. The results of this study are discussed in terms of their implications for interpreting drug interactions with morphine and with relationship to morphine's mode of action at mu and kappa opioid receptors.
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Affiliation(s)
- I M Maisonneuve
- Center for Neuropharmacology and Neuroscience, MC-136, Albany Medical College, 47 New Scotland Ave, Albany, NY 12208, USA.
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32
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Pettit HO, Batsell WR, Mueller K. Triazolam attenuates amphetamine but not morphine conditioned place preferences. Psychopharmacology (Berl) 2001; 98:483-6. [PMID: 2505288 DOI: 10.1007/bf00441946] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
In a series of four experiments the benzodiazepine triazolam was tested for reinforcing effects and for effects on reinforcement induced by amphetamine and morphine. Reinforcement was assessed in a conditioned place preference paradigm. Triazolam did not produce reinforcing or aversive effects when administered in doses ranging from 0.0625 to 0.5 mg/kg. Triazolam did attenuate reinforcing effects produced by 0.75 and 1.25 mg/kg amphetamine. No effect of triazolam was observed on morphine-induced reinforcement. These results indicate that the administration of triazolam can affect the brain mechanisms that mediate the reinforcing effects of amphetamine but not morphine.
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Affiliation(s)
- H O Pettit
- Department of Chemistry, Emory University, Atlanta, GA
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33
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Dockstader CL, Rubinstein M, Grandy DK, Low MJ, van der Kooy D. The D2 receptor is critical in mediating opiate motivation only in opiate-dependent and withdrawn mice. Eur J Neurosci 2001; 13:995-1001. [PMID: 11264672 DOI: 10.1046/j.1460-9568.2001.01455.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
According to the dual systems model for opiate reward, dopamine mediates opiate motivation when an animal is in a deprived motivational state (i.e. opiate-dependent and in withdrawal) and not when an animal is in a nondeprived state (i.e. previously drug-naive). To determine the role of the D2 dopamine receptor subtype in mediating opiate motivation, we examined the behaviour of N5 congenic D2 receptor knockout mice and their wild-type siblings in opiate-naive and opiate-dependent and withdrawn place conditioning paradigms. Opiate-naive D2 receptor knockout mice demonstrated acquisition of morphine-conditioned place preference but failed to acquire place preference when conditioned in the deprived state. We propose that D2 receptor function is critical in mediating the motivational effects of opiates only when the animal is in an opiate-dependent and withdrawn motivational state. These findings also underscore the important influence of the genetic background to a given phenotype, as evidenced by the observation that increasing the allelic contribution from the 129/SvJ strain abolishes morphine place preference in C57BL/6 wild-type mice.
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Affiliation(s)
- C L Dockstader
- Department of Anatomy and Cell Biology, University of Toronto, Toronto, On M5S 1A8, Canada.
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34
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Ikemoto S, Panksepp J. The role of nucleus accumbens dopamine in motivated behavior: a unifying interpretation with special reference to reward-seeking. BRAIN RESEARCH. BRAIN RESEARCH REVIEWS 1999; 31:6-41. [PMID: 10611493 DOI: 10.1016/s0165-0173(99)00023-5] [Citation(s) in RCA: 955] [Impact Index Per Article: 38.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Studies addressing behavioral functions of dopamine (DA) in the nucleus accumbens septi (NAS) are reviewed. A role of NAS DA in reward has long been suggested. However, some investigators have questioned the role of NAS DA in rewarding effects because of its role in aversive contexts. As findings supporting the role of NAS DA in mediating aversively motivated behaviors accumulate, it is necessary to accommodate such data for understanding the role of NAS DA in behavior. The aim of the present paper is to provide a unifying interpretation that can account for the functions of NAS DA in a variety of behavioral contexts: (1) its role in appetitive behavioral arousal, (2) its role as a facilitator as well as an inducer of reward processes, and (3) its presently undefined role in aversive contexts. The present analysis suggests that NAS DA plays an important role in sensorimotor integrations that facilitate flexible approach responses. Flexible approach responses are contrasted with fixed instrumental approach responses (habits), which may involve the nigro-striatal DA system more than the meso-accumbens DA system. Functional properties of NAS DA transmission are considered in two stages: unconditioned behavioral invigoration effects and incentive learning effects. (1) When organisms are presented with salient stimuli (e.g., novel stimuli and incentive stimuli), NAS DA is released and invigorates flexible approach responses (invigoration effects). (2) When proximal exteroceptive receptors are stimulated by unconditioned stimuli, NAS DA is released and enables stimulus representations to acquire incentive properties within specific environmental context. It is important to make a distinction that NAS DA is a critical component for the conditional formation of incentive representations but not the retrieval of incentive stimuli or behavioral expressions based on over-learned incentive responses (i.e., habits). Nor is NAS DA essential for the cognitive perception of environmental stimuli. Therefore, even without normal NAS DA transmission, the habit response system still allows animals to perform instrumental responses given that the tasks take place in fixed environment. Such a role of NAS DA as an incentive-property constructor is not limited to appetitive contexts but also aversive contexts. This dual action of NAS DA in invigoration and incentive learning may explain the rewarding effects of NAS DA as well as other effects of NAS DA in a variety of contexts including avoidance and unconditioned/conditioned increases in open-field locomotor activity. Particularly, the present hypothesis offers the following interpretation for the finding that both conditioned and unconditioned aversive stimuli stimulate DA release in the NAS: NAS DA invigorates approach responses toward 'safety'. Moreover, NAS DA modulates incentive properties of the environment so that organisms emit approach responses toward 'safety' (i.e., avoidance responses) when animals later encounter similar environmental contexts. There may be no obligatory relationship between NAS DA release and positive subjective effects, even though these systems probably interact with other brain systems which can mediate such effects. The present conceptual framework may be valuable in understanding the dynamic interplay of NAS DA neurochemistry and behavior, both normal and pathophysiological.
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Affiliation(s)
- S Ikemoto
- Behavioral Neuroscience Branch, Intramural Research Program, National Institute on Drug Abuse, Baltimore, MD 21224, USA.
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35
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Abstract
Mesolimbic dopaminergic neurons are thought to serve as a final common neural pathway for mediating reinforcement processes. However, several recent findings have challenged the view that mesolimbic dopamine has a crucial role in the maintenance of reinforcement processes, or the subjective rewarding actions of natural rewards and drugs of abuse. Instead, there is growing evidence that dopamine is involved in the formation of associations between salient contextual stimuli and internal rewarding or aversive events. This evidence suggests that dopaminergic-neuron activation aids the organism in learning to recognize stimuli associated with such events. Thus, mesolimbic dopaminergic neurons have an important function in the acquisition of behavior reinforced by natural reward and drug stimuli. Furthermore, long-lasting neuroadaptive changes in mesolimbic dopamine-mediated transmission that develop during chronic drug use might contribute to compulsive drug-seeking behavior and relapse.
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Affiliation(s)
- R Spanagel
- Max Planck Institute of Psychiatry, 80804 Munich, Germany
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36
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Abstract
GABAergic neurons in the ventral tegmental area (VTA) play a primary role in local inhibition of mesocorticolimbic dopamine (DA) neurons but are not physiologically or anatomically well characterized. We used in vivo extracellular and intracellular recordings in the rat VTA to identify a homogeneous population of neurons that were distinguished from DA neurons by their rapid-firing, nonbursting activity (19.1 +/- 1.4 Hz), short-duration action potentials (310 +/- 10 microseconds), EPSP-dependent spontaneous spikes, and lack of spike accommodation to depolarizing current pulses. These non-DA neurons were activated both antidromically and orthodromically by stimulation of the internal capsule (IC; conduction velocity, 2.4 +/- 0.2 m/sec; refractory period, 0.6 +/- 0.1 msec) and were inhibited by stimulation of the nucleus accumbens septi (NAcc). Their firing rate was moderately reduced, and their IC-driven activity was suppressed by microelectrophoretic application or systemic administration of NMDA receptor antagonists. VTA non-DA neurons were recorded intracellularly and showed relatively depolarized resting membrane potentials (-61.9 +/- 1.8 mV) and small action potentials (68.3 +/- 2.1 mV). They were injected with neurobiotin and shown by light microscopic immunocytochemistry to be multipolar cells and by electron microscopy to contain GABA but not the catecholamine-synthesizing enzyme tyrosine hydroxylase (TH). Neurobiotin-filled dendrites containing GABA received asymmetric excitatory-type synapses from unlabeled terminals and symmetric synapses from terminals that also contained GABA. These findings indicate that VTA non-DA neurons are GABAergic, project to the cortex, and are controlled, in part, by a physiologically relevant NMDA receptor-mediated input from cortical structures and by GABAergic inhibition.
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37
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Abstract
Drug addiction is characterized by motivational disturbances such as compulsive drug taking and episodes of intense drug craving. Recent advances using animal models of relapse have shown that drug-seeking behaviour can be triggered by drug-associated cues, by stress and by 'priming' injections of the drugs themselves, events also known to trigger drug craving in human drug addicts. Current evidence suggests that these stimuli all induce relapse, at least in part, by their common ability to activate the mesolimbic dopamine system. Drug-associated cues and stress can activate this system via neural circuits from the prefrontal cortex and amygdala and through activation of the hypothalamic-pituitary-adrenal axis. Our studies suggest that dopamine triggers relapse to drug-seeking behaviour by stimulating D2-dopamine receptors which inhibit the cyclic AMP second messenger pathway in the neurones of the nucleus accumbens. In contrast, compounds which activate D1 receptors prevent relapse to drug-seeking behaviour, possibly through satiation of reward pathways. Chronic neuroadaptations in dopamine receptor signalling pathways in the nucleus accumbens caused by repeated drug use are hypothesized to produce tolerance to the rewarding effects of D1-receptor stimulation, leading to increased drug intake during drug self-administration. Conversely, these same neuroadaptations are hypothesized to enhance drug craving by potentiating D2 receptor-mediated signals during abstinence. These findings identify D1 and D2-dopamine receptor mechanisms as potential targets for developing anticraving compounds to treat drug addiction.
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Affiliation(s)
- D W Self
- Division of Molecular Psychiatry, Center for Genes and Behavior, Yale University School of Medicine and Connecticut Mental Health Center, New Haven 06508, USA.
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38
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Abstract
Social play behavior is one of the earliest forms of non-mother-directed social behavior appearing in ontogeny in mammalian species. During the last century, there has been a lot of debate on the significance of social play behavior, but behavioral studies have indicated that social play behavior is a separate and relevant category of behavior. The present review provides a comprehensive survey of studies on the neurobiology of social play behavior. Evidence is presented that opioid and dopamine systems play a role in the reward aspect of social play behavior. The role of cholinergic, noradrenergic and opioid systems in attentional processes underlying the generation of social play behavior and the involvement of androgens in the sexual differentiation of social play behavior in rats is summarized. It is concluded that there is not only behavioral, but also neurobiological evidence to suggest that social play behavior represents a separate category of behavior, instead of a precursor for adult social, sexual or aggressive behavior.
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Affiliation(s)
- L J Vanderschuren
- Department of Medical Pharmacology, Rudolf Magnus Institute for Neurosciences, Faculty of Medicine, Utrecht University, The Netherlands.
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39
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Nader K, Bechara A, van der Kooy D. Neurobiological constraints on behavioral models of motivation. Annu Rev Psychol 1997; 48:85-114. [PMID: 9046556 DOI: 10.1146/annurev.psych.48.1.85] [Citation(s) in RCA: 79] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The application of neurobiological tools to behavioral questions has produced a number of working models of the mechanisms mediating the rewarding and aversive properties of stimuli. The authors review and compare three models that differ in the nature and number of the processes identified. The dopamine hypothesis, a single system model, posits that the neurotransmitter dopamine plays a fundamental role in mediating the rewarding properties of all classes of stimuli. In contrast, both nondeprived/deprived and saliency attribution models claim that separate systems make independent contributions to reward. The former identifies the psychological boundary defined by the two systems as being between states of nondeprivation (e.g. food sated) and deprivation (e.g. hunger). The latter identifies a boundary between liking and wanting systems. Neurobiological dissociations provide tests of and explanatory power for behavioral theories of goal-directed behavior.
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Affiliation(s)
- K Nader
- Department of Anatomy and Cell Biology, University of Toronto, Ontario, Canada
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40
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Olmstead MC, Franklin KB. Differential effects of ventral striatal lesions on the conditioned place preference induced by morphine or amphetamine. Neuroscience 1996; 71:701-8. [PMID: 8867042 DOI: 10.1016/0306-4522(95)00486-6] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The present experiment examined the role of the ventral striatum in the rewarding effect of morphine and amphetamine by testing whether lesions of cell bodies within this region disrupt the development of a conditioned place preference to either drug. Bilateral, N-methyl-D-aspartate- or kainic acid-induced lesions of the ventral striatum block a conditioned place preference to amphetamine (1.5 mg/kg x 3 pairings) but not to morphine (2 mg/kg x 3 pairings). Because both lesions spared anterior portions of the ventral striatum, we examined the effect of larger or more selective ventral striatal lesions on a conditioned place preference induced by morphine. Destruction of the entire ventral striatum reduced, but did not eliminate, a conditioned place preference to morphine, whereas selective lesions of the anterior ventral striatum were ineffective. These results indicate that the ventral striatum is not critically involved in morphine's rewarding effect and support the suggestion that the rewarding effects of opiates and stimulants do not involve identical neural substrates.
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Affiliation(s)
- M C Olmstead
- Department of Psychology, McGill University, Montreal, Quebec, Canada
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41
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Self DW, McClenahan AW, Beitner-Johnson D, Terwilliger RZ, Nestler EJ. Biochemical adaptations in the mesolimbic dopamine system in response to heroin self-administration. Synapse 1995; 21:312-8. [PMID: 8869161 DOI: 10.1002/syn.890210405] [Citation(s) in RCA: 77] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Previous studies have shown that chronic, forced exposure to opiates produces specific biochemical adaptations in the ventral tegmental area (VTA) and nucleus accumbens (NAc). The functional consequences of these adaptations have been hypothesized to contribute to certain motivational aspects of drug addiction. In this study, the possibility that similar adaptations could occur in response to intermittent heroin self-administration was tested by comparing homogenates of VTA and NAc from rats self-administering heroin, rats receiving yoked injections of heroin, and rats receiving yoked injections of saline (controls). Tyrosine hydroxylase (TH) immunoreactivity was increased (31-38%) in the VTA and decreased (11%) in the NAc of heroin-exposed rats relative to controls. Heroin exposure also increased cAMP-dependent protein kinase (PKA) activity in both particulate (19-27%) and soluble (17-20%) fractions of the NAc, and decreased (16-17%) the level of Gi alpha immunoreactivity in this brain region. In contrast, no significant biochemical changes were found in the substantia nigra or caudate-putamen, indicating a selective effect on the mesolimbic dopamine system. Overall, adaptations in the VTA and NAc of heroin-exposed rats were similar to, but generally smaller in magnitude than, adaptations produced by chronic morphine administration. However, in contrast to morphine-treated animals, heroin-exposed animals failed to display overt signs of opiate physical dependence, suggesting that adaptations in motivational systems may occur more readily than adaptations in brain regions associated with physical dependence.
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Affiliation(s)
- D W Self
- Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut 06508, USA
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42
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Wise RA, Leone P, Rivest R, Leeb K. Elevations of nucleus accumbens dopamine and DOPAC levels during intravenous heroin self-administration. Synapse 1995; 21:140-8. [PMID: 8584975 DOI: 10.1002/syn.890210207] [Citation(s) in RCA: 136] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Extracellular dopamine and DOPAC (3,4-dihydroxyphenylacetic acid) levels in nucleus accumbens were sampled by microdialysis and quantified with high-performance liquid chromatography during intravenous heroin self-administration sessions in rats. Dopamine levels in 10 and 20 min samples were elevated following the first injection of each session, reaching a plateau of elevation within the first two or three injections and falling back toward baseline only when drug access was terminated. Elevations were in the range of 150-300% when unit dosages of 0.05-0.2 mg/kg were given. Increasing the work requirement from FR-1 to FR-10 did not appear to alter the degree of elevation of dopamine levels, and dopamine levels fell during extinction while lever-pressing rates increased 20-fold. While animals compensated for unit dose changes between 0.05 and 0.2 mg/kg/injection, adjusting their response rate such that the same hourly drug intake and the same asymptotic dopamine levels were maintained across these conditions, at 0.4 mg/kg/injection hourly drug intake and asymptotic dopamine levels were elevated beyond the levels sustained by the lower doses. These findings confirm that self-administered doses of intravenous heroin are sufficient to activate the mesolimbic dopamine system and suggest that significant heroin "craving" can emerge when dopamine levels are still moderately elevated, long before the development of dopamine depletion associated with opiate withdrawal.
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Affiliation(s)
- R A Wise
- Department of Psychology, Concordia University, Montreal, Quebec, Canada
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43
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Johnson PI, Goodman JB, Condon R, Stellar JR. Reward shifts and motor responses following microinjections of opiate-specific agonists into either the core or shell of the nucleus accumbens. Psychopharmacology (Berl) 1995; 120:195-202. [PMID: 7480552 DOI: 10.1007/bf02246193] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Differences in pharmacology, anatomical connections, and receptor densities between the "core" and "shell" of the nucleus accumbens suggest that behavioral activity normally modulated by the accumbens, such as reward and motor functions, may be differentially regulated across the mediolateral axis. This study investigated the effects of opiate receptor-specific agonists on reward and motor functions in either the accumbens core or shell, using the intracranial self-stimulation (ICSS) rate-frequency curve-shift method. Microinjections of the mu opiate receptor-specific agonist, DAMGO (vehicle, 0.03 nmol, and 0.3 nmol), or the delta opiate receptor-specific agonist DPDPE (vehicle, 0.3 nmol, 3.0 nmol), were administered bilaterally in a random dose order with a minimum of 3 days between injections. Rats were tested over three consecutive 20-min rate-frequency curves immediately following a microinjection to investigate the time course of drug effects. Both opiate agonists decreased the ICSS frequency necessary to maintain half-maximal response rates when injected into the medial and ventral shell region of the accumbens. However, DAMGO microinjections into the lateral accumbens core or the control site of the caudate increased the frequency necessary to elicit half-maximal response rates, while DPDPE microinjections into these regions had no effect. Evaluation of motor effects show that administration of DAMGO resulted in a suppression of activity in all locations. In contrast, DPDPE microinjections resulted in little or no effect on lever pressing activity at any location.
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MESH Headings
- Analgesics/pharmacology
- Animals
- Behavior, Animal/drug effects
- Conditioning, Operant/drug effects
- Dose-Response Relationship, Drug
- Enkephalin, Ala(2)-MePhe(4)-Gly(5)-
- Enkephalin, D-Penicillamine (2,5)-
- Enkephalins/pharmacology
- Male
- Microinjections
- Motor Activity/drug effects
- Nucleus Accumbens/drug effects
- Rats
- Rats, Inbred Strains
- Receptors, Opioid, delta/agonists
- Receptors, Opioid, mu/agonists
- Time Factors
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Affiliation(s)
- P I Johnson
- Department of Psychology, Northeastern University, Boston, MA 02115, USA
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44
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Abstract
Drugs of abuse share with conventional reinforcers the activation of specific neural pathways in the CNS that are the substrate of their motivational properties. Dopamine is recognized as the transmitter of one such neural pathway, being involved in at least three major aspects of motivation: modulation of motivational state, acquisition (incentive learning) and expression of incentive properties by motivational stimuli. Drugs of abuse of different pharmacological classes stimulate in the low dose range dopamine transmission particularly in the ventral striatum. Apart from psychostimulants, the evidence that stimulation of dopamine transmission by drugs of abuse provides the primary motivational stimulus for drug self-administration is either unconvincing or negative. However, stimulation of dopamine transmission is essential for the activational properties of drugs of abuse and might be instrumental for the acquisition of responding to drug-related incentive stimuli (incentive learning). Dopamine is involved in the induction and in the expression of behavioural sensitization by repeated exposure to various drugs of abuse. Sensitization to the dopamine-stimulant properties of specific drug classes leading to facilitation of incentive learning of drug-related stimuli might account for the strong control over behaviour exerted by these stimuli in the addiction state. Withdrawal from drugs of abuse results in a reduction in basal dopamine transmission in vivo and in reduced responding for conventional reinforcers. Although these changes are likely to be the expression of a state of dependence of the dopamine system their contribution to the motivational state of drug addiction is unclear.
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Affiliation(s)
- G Di Chiara
- Department of Toxicology, University of Cagliari, Italy
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45
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Johnson PI, Stellar JR. N-methyl-D-aspartic acid-induced lesions of the nucleus accumbens and/or ventral pallidum fail to attenuate lateral hypothalamic self-stimulation reward. Brain Res 1994; 646:73-84. [PMID: 8055342 DOI: 10.1016/0006-8993(94)90059-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The role of ventral striatum in the maintenance and transmission of a hypothalamic intracranial self-stimulation (ICSS) reward signal was investigated using the rate-frequency multiple-curve shift paradigm. The excitotoxin N-methyl-D-aspartic acid (NMDA) was bilaterally administered into the nucleus accumbens (15 micrograms per side), the ventral pallidum (15 micrograms per side) or the juncture between the two structures (20 micrograms per side) creating three lesion groups. Both the nucleus accumbens (NAC) lesion group and the ventral pallidum (VP) lesion group displayed substantial NMDA-induced damage which was generally restricted to the intended limbic structure. The NMDA lesions in the third group displayed extensive damage to both the NAC and VP, as intended, but also typically diffused into adjacent medial structures. NMDA-induced lesions in all groups caused a suppression in motor/performance activity at all currents tested. Contrary to motor effects, reward efficacy was relatively unaffected for the NAC and VP groups. The lack of reward effects may be due to plasticity of neuronal systems and redundancy of circuit connections. However, this explanation is questionable given the fact that NMDA lesions which encompassed both the NAC and VP had little effect on reward efficacy. The above data suggests that the nucleus accumbens and the ventral pallidum are not critical for ICSS rewards stimulation and that hypothalamic ICSS reward signals are processed downstream from these limbic structures.
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Affiliation(s)
- P I Johnson
- Department of Psychology, Northeastern University, Boston, MA 02115
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46
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Henry DJ, Wise RA, Rompré PP, White FJ. Acute depolarization block of A10 dopamine neurons: interactions of morphine with dopamine antagonists. Brain Res 1992; 596:231-7. [PMID: 1467986 DOI: 10.1016/0006-8993(92)91552-p] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Extracellular single-unit recording techniques were used to determine the effects of morphine, administered either systematically (intravenous) or locally (microiontophoresis), on ventral tegmental area (A10) dopamine (DA) neuronal activity in animals pretreated with D1 (SCH 23390) or D2 (pimozide) DA receptor antagonists. In rats pretreated with the D2 antagonist pimozide, A10 DA neurons readily entered a state of apparent depolarization block in response to either i.v. or iontophoretically applied morphine. Whether the inactivation of DA neurons was induced by systemic or local morphine, it was reversed in 22 of 27 cases by iontophoretic administration of the inhibitory amino acid transmitter gamma-aminobutyric acid (GABA), suggesting depolarization block as the underlying mechanism. Pretreatment of rats with the D1 antagonist SCH 23390 did not significantly alter the tendency of A10 DA neurons to enter apparent depolarization block in response to morphine. These data support recent behavioral evidence suggesting that the combination of systemic pimozide and ventral tegmental area morphine can result in depolarization inactivation of the mesoaccumbens DA reward system.
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Affiliation(s)
- D J Henry
- Wayne State University School of Medicine, Department of Psychiatry, Detroit, MI 48207
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47
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Abstract
The dependence creating properties of drugs are mediated by structures in the brain. The mesolimbic system seems to play a crucial role in the behaviourally reinforcing effects of opiates and other drugs of abuse. The significance of dopamine in opiate reinforcement is still a matter of debate, in spite of the large number of studies on this subject. Dopamine appears to be involved in conditioning processes and in drug self-administration behaviour only once it has been established. Neuropeptides, centrally active fragments of hormones, may play a role in the individual vulnerability for the development of drug dependence. Administration of a number of wellknown neuropeptides attenuates the acquisition of drug self-administration behaviour. The virtues and flaws of some widely used animal models for drug dependence are discussed.
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Affiliation(s)
- N F Ramsey
- Department of Pharmacology, Rudolf Magnus Institute, Medical Faculty, University of Utrecht, The Netherlands
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48
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Stinus L, Cador M, Le Moal M. Interaction between endogenous opioids and dopamine within the nucleus accumbens. Ann N Y Acad Sci 1992; 654:254-73. [PMID: 1321572 DOI: 10.1111/j.1749-6632.1992.tb25972.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- L Stinus
- Laboratoire de Psychobiologie des Comportements Adaptatifs, INSERM U. 259, Université de Bordeaux II, France
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49
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Quarfordt SD, Kalmus GW, Myers RD. Ethanol drinking following 6-OHDA lesions of nucleus accumbens and tuberculum olfactorium of the rat. Alcohol 1991; 8:211-7. [PMID: 1906282 DOI: 10.1016/0741-8329(91)90854-p] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Previous studies have shown that lesions of the dopaminergic system in the brain produced by an intracerebroventricular injection of the neurotoxin, 6-hydroxydopamine (6-OHDA), evoke significant changes in ethanol drinking. In the present experiments, dopaminergic systems of Sprague-Dawley rats were lesioned by 6-OHDA infused into either the tuberculum olfactorium or nucleus accumbens, two of the structures implicated in drug-related reinforcement. Prior to the lesion and immediately thereafter, tests for ethanol preference were undertaken in which water was offered in a self-selection situation together with ethanol which was increased in concentration from 3-30% over a 10-day interval. Following the circumscribed ablation of dopaminergic neurons within either the N. accumbens or tuberculum olfactorium, preference for ethanol increased significantly with absolute intakes exceeding 4.0 g/kg at the 7% concentration during the first postlesion drinking test. During the second postlesion preference test, the mean consumption of ethanol exceeded 6.0 g/kg at the 11% concentration and 4.0 to 5.0 g/kg at the 20 and 30 percent concentrations offered to the rats. When adjacent areas just dorsal or lateral to these structures were lesioned by 6-OHDA, no significant change in consumption of ethanol occurred. Thus, it is envisaged that one of the functional roles for the dopaminergic neurons of the N. accumbens and tuberculum olfactorium is to regulate the craving for a drug with addictive liability such as ethanol. As a result of an impairment of normal function of dopamine receptors or a perturbation in the release of this catecholaminergic neurotransmitter, ethanol becomes reinforcing upon repeated exposure. Thus, an addictive-like state consequently ensues. Finally, it is envisaged that the control mechanism underlying the function of the dopaminergic neurons in the medial-basal forebrain is functionally disinhibited in individuals that consume ethanol to the point of abuse.
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Affiliation(s)
- S D Quarfordt
- Department of Pharmacology, School of Medicine, East Carolina University, Greenville, NC 27858
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Porrino LJ, Dworkin SI, Smith JE. Basal forebrain involvement in self-administration of drugs of abuse. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1991; 295:339-51. [PMID: 1776576 DOI: 10.1007/978-1-4757-0145-6_19] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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