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Kahvandi N, Ebrahimi Z, Sharifi M, Karimi SA, Shahidi S, Salehi I, Haddadi R, Sarihi A. S-3,4-DCPG, a potent orthosteric agonist for the mGlu8 receptor, facilitates extinction and inhibits the reinstatement of morphine-induced conditioned place preference in male rats. Pharmacol Biochem Behav 2024; 240:173772. [PMID: 38653345 DOI: 10.1016/j.pbb.2024.173772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2023] [Revised: 04/13/2024] [Accepted: 04/17/2024] [Indexed: 04/25/2024]
Abstract
The limbic system, particularly the NAc, shows a high concentration of metabotropic glutamate receptors (mGluRs). Recent evidence suggests the significant involvement of mGluRs in mental disorders, including substance abuse and addiction. The objective of this study was to examine the involvement of mGlu8 receptors in the NAc in the mechanisms underlying the extinction and reinstatement of conditioned place preference (CPP) induced by morphine. Male Wistar rats underwent surgical implantation of bilateral cannulas in the NAc and were assessed in a CPP protocol. In study 1 at the same time as the extinction phase, the rats were given varying doses of S-3,4-DCPG (0.03, 0.3, and 3 μg/0.5 μl). In study 2, rats that had undergone CPP extinction were given S-3,4-DCPG (0.03, 0.3, and 3 μg/0.5 μl) five minutes prior to receiving a subthreshold dose of morphine (1 mg/kg) in order to reactivate the previously extinguished morphine response. The findings demonstrated that administering S-3,4-DCPG directly into the accumbens nucleus resulted in a decrease in the duration of the CPP extinction phase. Moreover, dose-dependent administration of S-3,4-DCPG into the NAc inhibited CPP reinstatement. The observations imply that microinjection of S-3,4-DCPG as a potent orthosteric agonist with high selectivity for the mGlu8 receptor into the NAc promotes the process of extinction while concurrently exerting inhibitory effects on the reinstatement of morphine-induced CPP. This effect may be associated with the modulation of glutamate engagement within the NAc and the plasticity of reward pathways at the synaptic level.
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Affiliation(s)
- Nazanin Kahvandi
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran; Department of Physiology, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Zahra Ebrahimi
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran; Department of Physiology, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Maryam Sharifi
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Seyed Asaad Karimi
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran; Department of Neuroscience, School of Sciences and Advanced Technology in Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Siamak Shahidi
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran; Department of Neuroscience, School of Sciences and Advanced Technology in Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Iraj Salehi
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran; Department of Neuroscience, School of Sciences and Advanced Technology in Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Rasool Haddadi
- Department of Pharmacology and Toxicology, School of Pharmacy, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Abdolrahman Sarihi
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran; Department of Neuroscience, School of Sciences and Advanced Technology in Medicine, Hamadan University of Medical Sciences, Hamadan, Iran.
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Nicosia N, Giovenzana M, Misztak P, Mingardi J, Musazzi L. Glutamate-Mediated Excitotoxicity in the Pathogenesis and Treatment of Neurodevelopmental and Adult Mental Disorders. Int J Mol Sci 2024; 25:6521. [PMID: 38928227 PMCID: PMC11203689 DOI: 10.3390/ijms25126521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2024] [Revised: 06/09/2024] [Accepted: 06/11/2024] [Indexed: 06/28/2024] Open
Abstract
Glutamate is the main excitatory neurotransmitter in the brain wherein it controls cognitive functional domains and mood. Indeed, brain areas involved in memory formation and consolidation as well as in fear and emotional processing, such as the hippocampus, prefrontal cortex, and amygdala, are predominantly glutamatergic. To ensure the physiological activity of the brain, glutamatergic transmission is finely tuned at synaptic sites. Disruption of the mechanisms responsible for glutamate homeostasis may result in the accumulation of excessive glutamate levels, which in turn leads to increased calcium levels, mitochondrial abnormalities, oxidative stress, and eventually cell atrophy and death. This condition is known as glutamate-induced excitotoxicity and is considered as a pathogenic mechanism in several diseases of the central nervous system, including neurodevelopmental, substance abuse, and psychiatric disorders. On the other hand, these disorders share neuroplasticity impairments in glutamatergic brain areas, which are accompanied by structural remodeling of glutamatergic neurons. In the current narrative review, we will summarize the role of glutamate-induced excitotoxicity in both the pathophysiology and therapeutic interventions of neurodevelopmental and adult mental diseases with a focus on autism spectrum disorders, substance abuse, and psychiatric disorders. Indeed, glutamatergic drugs are under preclinical and clinical development for the treatment of different mental diseases that share glutamatergic neuroplasticity dysfunctions. Although clinical evidence is still limited and more studies are required, the regulation of glutamate homeostasis is attracting attention as a potential crucial target for the control of brain diseases.
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Affiliation(s)
- Noemi Nicosia
- School of Medicine and Surgery, University of Milano-Bicocca, 20900 Monza, Italy; (N.N.); (M.G.); (P.M.)
- PhD Program in Neuroscience, School of Medicine and Surgery, University of Milano-Bicocca, 20900 Monza, Italy
| | - Mattia Giovenzana
- School of Medicine and Surgery, University of Milano-Bicocca, 20900 Monza, Italy; (N.N.); (M.G.); (P.M.)
- PhD Program in Neuroscience, School of Medicine and Surgery, University of Milano-Bicocca, 20900 Monza, Italy
| | - Paulina Misztak
- School of Medicine and Surgery, University of Milano-Bicocca, 20900 Monza, Italy; (N.N.); (M.G.); (P.M.)
| | - Jessica Mingardi
- School of Medicine and Surgery, University of Milano-Bicocca, 20900 Monza, Italy; (N.N.); (M.G.); (P.M.)
| | - Laura Musazzi
- School of Medicine and Surgery, University of Milano-Bicocca, 20900 Monza, Italy; (N.N.); (M.G.); (P.M.)
- Fondazione IRCCS San Gerardo dei Tintori, 20900 Monza, Italy
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3
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Fitzgerald ND, Liu Y, Wang A, Striley CW, Setlow B, Knackstedt L, Cottler LB. Sequencing hour-level temporal patterns of polysubstance use among persons who use cocaine, alcohol, and cannabis: A back-translational approach. Drug Alcohol Depend 2024; 258:111272. [PMID: 38555662 DOI: 10.1016/j.drugalcdep.2024.111272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 03/07/2024] [Accepted: 03/19/2024] [Indexed: 04/02/2024]
Abstract
BACKGROUND Polysubstance use is highly prevalent among persons who use cocaine; however, little is known about how alcohol and cannabis are used with cocaine. We identified temporal patterns of cocaine+alcohol and cocaine+cannabis polysubstance use to inform more translationally relevant preclinical models. METHODS Participants who used cocaine plus alcohol and/or cannabis at least once in the past 30 days (n=148) were interviewed using the computerized Substance Abuse Module and the newer Polysubstance Use-Temporal Patterns Section. For each day in the past 30 days, participants reported whether they had used cocaine, alcohol, and cannabis; if any combinations of use were endorsed, participants described detailed hourly use of each substance on the most "typical day" for the combination. Sequence analysis and hierarchical clustering were applied to identify patterns of timing of drug intake on typical days of cocaine polysubstance use. RESULTS We identified five temporal patterns among the 180 sequences of reported cocaine polysubstance use: 1) limited cocaine/cocaine+alcohol use (53%); 2) extensive cannabis then cocaine+alcohol+cannabis use (22%); 3) limited alcohol/cannabis then cocaine+alcohol use (13%); 4) extensive cocaine+cannabis then cocaine+alcohol+cannabis use (4%); and 5) extensive cocaine then cocaine+alcohol use (8%). While drug intake patterns differed, prevalence of use disorders did not. CONCLUSIONS Patterns were characterized by cocaine, alcohol, and cannabis polysubstance use and by the timing, order, duration, and quantity of episode-level substance use. The identification of real-world patterns of cocaine polysubstance use represents an important step toward developing laboratory models that accurately reflect human behavior.
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Affiliation(s)
- Nicole D Fitzgerald
- Department of Epidemiology, Colleges of Medicine and Public Health & Health Professions, University of Florida, Gainesville, FL, USA; Center for Addiction Research and Education, University of Florida, Gainesville, FL, USA.
| | - Yiyang Liu
- Department of Epidemiology, Colleges of Medicine and Public Health & Health Professions, University of Florida, Gainesville, FL, USA; Center for Addiction Research and Education, University of Florida, Gainesville, FL, USA
| | - Anna Wang
- Department of Epidemiology, Colleges of Medicine and Public Health & Health Professions, University of Florida, Gainesville, FL, USA; Center for Addiction Research and Education, University of Florida, Gainesville, FL, USA
| | - Catherine W Striley
- Department of Epidemiology, Colleges of Medicine and Public Health & Health Professions, University of Florida, Gainesville, FL, USA; Center for Addiction Research and Education, University of Florida, Gainesville, FL, USA
| | - Barry Setlow
- Center for Addiction Research and Education, University of Florida, Gainesville, FL, USA; Department of Psychiatry, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Lori Knackstedt
- Center for Addiction Research and Education, University of Florida, Gainesville, FL, USA; Department of Psychology, College of Liberal Arts and Sciences, University of Florida, Gainesville, FL, USA
| | - Linda B Cottler
- Department of Epidemiology, Colleges of Medicine and Public Health & Health Professions, University of Florida, Gainesville, FL, USA; Center for Addiction Research and Education, University of Florida, Gainesville, FL, USA
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Clare K, Park K, Pan Y, Lejuez CW, Volkow ND, Du C. Neurovascular effects of cocaine: relevance to addiction. Front Pharmacol 2024; 15:1357422. [PMID: 38455961 PMCID: PMC10917943 DOI: 10.3389/fphar.2024.1357422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Accepted: 01/22/2024] [Indexed: 03/09/2024] Open
Abstract
Cocaine is a highly addictive drug, and its use is associated with adverse medical consequences such as cerebrovascular accidents that result in debilitating neurological complications. Indeed, brain imaging studies have reported severe reductions in cerebral blood flow (CBF) in cocaine misusers when compared to the brains of healthy non-drug using controls. Such CBF deficits are likely to disrupt neuro-vascular interaction and contribute to changes in brain function. This review aims to provide an overview of cocaine-induced CBF changes and its implication to brain function and to cocaine addiction, including its effects on tissue metabolism and neuronal activity. Finally, we discuss implications for future research, including targeted pharmacological interventions and neuromodulation to limit cocaine use and mitigate the negative impacts.
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Affiliation(s)
- Kevin Clare
- New York Medical College, Valhalla, NY, United States
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, United States
| | - Kicheon Park
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, United States
| | - Yingtian Pan
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, United States
| | - Carl W. Lejuez
- Department of Psychology, Stony Brook University, Stony Brook, NY, United States
| | - Nora D. Volkow
- National Institute on Alcohol Abuse and Alcoholism, Bethesda, MD, United States
| | - Congwu Du
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, United States
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Zhang J, Liu Z, Liu X, Wang X, Yu L. Intravenous Injection of GluR2-3Y Inhibits Repeated Morphine-Primed Reinstatement of Drug Seeking in Rats. Brain Sci 2023; 13:brainsci13040590. [PMID: 37190555 DOI: 10.3390/brainsci13040590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Revised: 03/25/2023] [Accepted: 03/28/2023] [Indexed: 04/03/2023] Open
Abstract
Studies have demonstrated that the α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptor is essential to drug addiction. In this study, we explored the influence of GluR2-3Y, an interfering peptide to prevent the endocytosis of AMPA receptors containing the GluR2 subunit, on morphine-seeking behavior in the rat self-administration model. After self-administration was established, the rats received intravenous injections of GluR2-3Y during the extinction sessions. There were no significant differences in both active and inactive pokes compared to the control group of rats that received GluR2-3S, indicating that GluR2-3Y has no significant influences on the extinction of morphine self-administration. The other two groups of rats were trained, extinguished, and reinstated by repeated morphine priming (respectively, called Prime 1, Prime 2, and Prime 3). Only one intravenous injection of GluR2-3Y was performed before Prime 1. Compared to the control group, GluR2-3Y did not affect Prime 1, but significantly attenuated the morphine-seeking behavior during repeated morphine-primed reinstatement, indicating an inhibitory after effect of GluR2-3Y on morphine-seeking behavior in rats. The long-term depression (LTD) in the nucleus accumbens (NAc) shell was also assessed. Pretreatment with GluR2-3Y altered the ability of LTD induction to the level of that in the naive group, while pretreatment with GluR2-3S had no effects on LTD. Our results demonstrated that the intravenous injection of GluR2-3Y, to block the endocytosis of AMPA receptors, inhibited the reinstatement of morphine-seeking behavior, which may be induced by modulating the neuronal plasticity in the NAc shell of rats.
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Affiliation(s)
- Jianjun Zhang
- College of Basic Medical, Shanxi University of Chinese Medicine, Jinzhong 030619, China
- Shanxi Key Laboratory of Chinese Medicine Encephalopathy, Jinzhong 030619, China
- CAS Key Laboratory of Mental Health, Institute of Psychology, Beijing 100101, China
| | - Zhuo Liu
- School of Crime Investigation, People’s Public Security University of China, Beijing 100038, China
| | - Xiaodong Liu
- Beijing Institute of Chinese Medicine, Beijing University of Chinese Medicine, Beijing 100029, China
| | - Xiaoqian Wang
- College of Basic Medical, Shanxi University of Chinese Medicine, Jinzhong 030619, China
- Shanxi Key Laboratory of Chinese Medicine Encephalopathy, Jinzhong 030619, China
| | - Longchuan Yu
- School of Life Sciences, Peking University, Beijing 100871, China
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Avalos MP, Guzman AS, Garcia-Keller C, Mongi-Bragato B, Esparza MA, Rigoni D, Sanchez MA, Calfa GD, Bollati FA, Cancela LM. Impairment of glutamate homeostasis in the nucleus accumbens core underpins cross-sensitization to cocaine following chronic restraint stress. Front Physiol 2022; 13:896268. [PMID: 36091376 PMCID: PMC9462460 DOI: 10.3389/fphys.2022.896268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 07/05/2022] [Indexed: 11/17/2022] Open
Abstract
Though the facilitating influence of stress on drug abuse is well documented, the mechanisms underlying this interaction have yet to be fully elucidated. The present study explores the neurobiological mechanisms underpinning the sensitized response to the psychomotor-stimulating effects of cocaine following chronic restraint stress (CRS), emphasizing the differential contribution of both subcompartments of the nucleus accumbens (NA), the core (NAcore) and shell (NAshell), to this phenomenon. Adult male Wistar rats were restrained for 2 h/day for 7 days and, 2 weeks after the last stress exposure (day 21), all animals were randomly assigned to behavioral, biochemical or neurochemical tests. Our results demonstrated that the enduring CRS-induced increase in psychostimulant response to cocaine was paralleled by an increase of extracellular dopamine levels in the NAcore, but not the NAshell, greater than that observed in the non-stress group. Furthermore, we found that CRS induced an impairment of glutamate homeostasis in the NAcore, but not the NAshell. Its hallmarks were increased basal extracellular glutamate concentrations driven by a CRS-induced downregulation of GLT-1, blunted glutamate levels in response to cocaine and postsynaptic structural remodeling in pre-stressed animals. In addition, ceftriaxone, a known GLT-1 enhancer, prevented the CRS-induced GLT-1 downregulation, increased basal extracellular glutamate concentrations and changes in structural plasticity in the NAcore as well as behavioral cross-sensitization to cocaine, emphasizing the biological importance of GLT-1 in the comorbidity between chronic stress exposure and drug abuse. A future perspective concerning the paramount relevance of the stress-induced disruption of glutamate homeostasis as a vulnerability factor to the development of stress and substance use disorders during early life or adulthood of descendants is provided.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Flavia A. Bollati
- Departamento de Farmacología Otto Orsingher, Instituto de Farmacología Experimental de Córdoba (IFEC-CONICET), Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Liliana M. Cancela
- Departamento de Farmacología Otto Orsingher, Instituto de Farmacología Experimental de Córdoba (IFEC-CONICET), Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
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Abstract
Drug addiction remains a key biomedical challenge facing current neuroscience research. In addition to neural mechanisms, the focus of the vast majority of studies to date, astrocytes have been increasingly recognized as an "accomplice." According to the tripartite synapse model, astrocytes critically regulate nearby pre- and postsynaptic neuronal substrates to craft experience-dependent synaptic plasticity, including synapse formation and elimination. Astrocytes within brain regions that are implicated in drug addiction exhibit dynamic changes in activity upon exposure to cocaine and subsequently undergo adaptive changes themselves during chronic drug exposure. Recent results have identified several key astrocytic signaling pathways that are involved in cocaine-induced synaptic and circuit adaptations. In this review, we provide a brief overview of the role of astrocytes in regulating synaptic transmission and neuronal function, and discuss how cocaine influences these astrocyte-mediated mechanisms to induce persistent synaptic and circuit alterations that promote cocaine seeking and relapse. We also consider the therapeutic potential of targeting astrocytic substrates to ameliorate drug-induced neuroplasticity for behavioral benefits. While primarily focusing on cocaine-induced astrocytic responses, we also include brief discussion of other drugs of abuse where data are available.
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Montemitro C, Angebrandt A, Wang TY, Pettorruso M, Abulseoud OA. Mechanistic insights into the efficacy of memantine in treating certain drug addictions. Prog Neuropsychopharmacol Biol Psychiatry 2021; 111:110409. [PMID: 34324921 DOI: 10.1016/j.pnpbp.2021.110409] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 06/23/2021] [Accepted: 07/22/2021] [Indexed: 01/11/2023]
Abstract
The deleterious effects of the drug addiction epidemic are compounded by treatment strategies that are only marginally efficacious. Memantine is a unique glutamatergic medication with proven ability to attenuate drug addiction in preclinical models. However, clinical translational studies are inconsistent. In this review, we summarize preclinical evidences and clinical trials that investigated the efficacy of memantine in treating patients with alcohol, opiate, cocaine, and nicotine use disorders and discuss the results from a mechanistic point of view. Memantine has shown efficacy in reducing alcohol and opiate craving, consumption, and withdrawal severity. However, in cocaine and nicotine use disorders, memantine did not have significant effect on cravings or consumption. Additionally, memantine was associated with increased subjective effects of alcohol, cocaine, and nicotine. We discuss possible mechanisms behind this variability. Since memantine transiently blocks NMDA receptors and protects neurons from overstimulation by excessive synaptic glutamate, its efficacy should be observed in drug phases that cause hyperglutamatergic states, while hypoglutamatergic drug use states would not resolve with blocking NMDA receptors. Second, memantine pharmacokinetic studies have been done in rodents and healthy volunteers, but not in patients with substance use disorder. Memantine, opiates, cocaine, and nicotine share the same transporter family at the blood brain barrier. This shared transport mechanism could impact brain concentrations of memantine and its effects. In conclusion, memantine remains an intriguing compound in our pharmacopeia with controversial results in treating certain aspects of drug addiction. Further studies are needed to understand the clinical and biological correlates of its efficacy.
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Affiliation(s)
- Chiara Montemitro
- Neuroimaging Research Branch, Intramural Research Program, National Institute on Drug Abuse, Baltimore, MD, USA; Department of Neuroscience & Imaging, Università degli Studi G. d'Annunzio Chieti e Pescara, Italy.
| | - Alexandra Angebrandt
- Neuroimaging Research Branch, Intramural Research Program, National Institute on Drug Abuse, Baltimore, MD, USA
| | - Tzu-Yun Wang
- Neuroimaging Research Branch, Intramural Research Program, National Institute on Drug Abuse, Baltimore, MD, USA; Department of Psychiatry, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Mauro Pettorruso
- Department of Neuroscience & Imaging, Università degli Studi G. d'Annunzio Chieti e Pescara, Italy
| | - Osama A Abulseoud
- Neuroimaging Research Branch, Intramural Research Program, National Institute on Drug Abuse, Baltimore, MD, USA; Department of Psychiatry and Psychology, Mayo Clinic, 5777 E Mayo Blvd, Phoenix, AZ, USA.
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9
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Guzman AS, Avalos MP, De Giovanni LN, Euliarte PV, Sanchez MA, Mongi-Bragato B, Rigoni D, Bollati FA, Virgolini MB, Cancela LM. CB1R activation in nucleus accumbens core promotes stress-induced reinstatement of cocaine seeking by elevating extracellular glutamate in a drug-paired context. Sci Rep 2021; 11:12964. [PMID: 34155271 PMCID: PMC8217548 DOI: 10.1038/s41598-021-92389-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 05/31/2021] [Indexed: 02/08/2023] Open
Abstract
Preclinical models of stress-induced relapse to drug use have shown that the dysregulation of glutamatergic transmission within the nucleus accumbens (NA) contributes notably to the reinstatement of cocaine-seeking behavior in rodents. In this sense, there has been increasing interest in the cannabinoid type-1 receptor (CB1R), due to its crucial role in modulating glutamatergic neurotransmission within brain areas involved in drug-related behaviors. This study explored the involvement of CB1R within the NA subregions in the restraint stress-induced reinstatement of cocaine-conditioned place preference (CPP), as well as in the regulation of glutamatergic transmission, by using a pharmacological approach and the in vivo microdialysis sampling technique in freely moving rats. CB1R blockade by the antagonist/inverse agonist AM251 (5 nmol/0.5 μl/side) or CB1R activation by the agonist ACEA (0.01 fmol/0.5 μl/side), prevented or potentiated restraint stress-induced reinstatement of cocaine-CPP, respectively, after local administration into NAcore, but not NAshell. In addition, microdialysis experiments demonstrated that restraint stress elicited a significant increase in extracellular glutamate in NAcore under reinstatement conditions, with the local administration of AM251 or ACEA inhibiting or potentiating this, respectively. Interestingly, this rise specifically corresponded to the cocaine-associated CPP compartment. We also showed that this context-dependent change in glutamate paralleled the expression of cocaine-CPP, and disappeared after the extinction of this response. Taken together, these findings demonstrated the key role played by CB1R in mediating reinstatement of cocaine-CPP after restraint stress, through modulation of the context-specific glutamate release within NAcore. Additionally, CB1R regulation of basal extracellular glutamate was demonstrated and proposed as the underlying mechanism.
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Affiliation(s)
- Andrea S Guzman
- Departamento de Farmacología, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, X5000HUA, Córdoba, Argentina.,Instituto de Farmacología Experimental de Córdoba (IFEC-CONICET), X5000HUA, Córdoba, Argentina
| | - Maria P Avalos
- Departamento de Farmacología, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, X5000HUA, Córdoba, Argentina.,Instituto de Farmacología Experimental de Córdoba (IFEC-CONICET), X5000HUA, Córdoba, Argentina
| | - Laura N De Giovanni
- Instituto de Farmacología Experimental de Córdoba (IFEC-CONICET), X5000HUA, Córdoba, Argentina
| | - Pia V Euliarte
- Instituto de Farmacología Experimental de Córdoba (IFEC-CONICET), X5000HUA, Córdoba, Argentina
| | - Marianela A Sanchez
- Departamento de Farmacología, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, X5000HUA, Córdoba, Argentina.,Instituto de Farmacología Experimental de Córdoba (IFEC-CONICET), X5000HUA, Córdoba, Argentina
| | - Bethania Mongi-Bragato
- Departamento de Farmacología, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, X5000HUA, Córdoba, Argentina.,Instituto de Farmacología Experimental de Córdoba (IFEC-CONICET), X5000HUA, Córdoba, Argentina
| | - Daiana Rigoni
- Departamento de Farmacología, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, X5000HUA, Córdoba, Argentina.,Instituto de Farmacología Experimental de Córdoba (IFEC-CONICET), X5000HUA, Córdoba, Argentina
| | - Flavia A Bollati
- Departamento de Farmacología, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, X5000HUA, Córdoba, Argentina.,Instituto de Farmacología Experimental de Córdoba (IFEC-CONICET), X5000HUA, Córdoba, Argentina
| | - Miriam B Virgolini
- Departamento de Farmacología, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, X5000HUA, Córdoba, Argentina.,Instituto de Farmacología Experimental de Córdoba (IFEC-CONICET), X5000HUA, Córdoba, Argentina
| | - Liliana M Cancela
- Departamento de Farmacología, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, X5000HUA, Córdoba, Argentina. .,Instituto de Farmacología Experimental de Córdoba (IFEC-CONICET), X5000HUA, Córdoba, Argentina.
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10
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Cocaine use disorder: A look at metabotropic glutamate receptors and glutamate transporters. Pharmacol Ther 2021; 221:107797. [DOI: 10.1016/j.pharmthera.2020.107797] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 11/04/2020] [Indexed: 01/08/2023]
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11
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Restoring glutamate homeostasis in the nucleus accumbens via endocannabinoid-mimetic drug prevents relapse to cocaine seeking behavior in rats. Neuropsychopharmacology 2021; 46:970-981. [PMID: 33514875 PMCID: PMC8115336 DOI: 10.1038/s41386-021-00955-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2020] [Revised: 12/13/2020] [Accepted: 12/29/2020] [Indexed: 12/23/2022]
Abstract
Impaired glutamate homeostasis is a key characteristic of the neurobiology of drug addiction in rodent models and contributes to the vulnerability to relapse to drug seeking. Although disrupted astrocytic and presynaptic regulation of glutamate release has been considered to constitute with impaired glutamate homeostasis in rodent model of drug relapse, the involvement of endocannabinoids (eCBs) in this neurobiological process has remained largely unknown. Here, using cocaine self-administration in rats, we investigated the role of endocannabinoids in impaired glutamate homeostasis in the core of nucleus accumbens (NAcore), which was indicated by augmentation of spontaneous synaptic glutamate release, downregulation of metabotropic glutamate receptor 2/3 (mGluR2/3), and mGluR5-mediated astrocytic glutamate release. We found that the endocannabinoid, anandamide (AEA), rather than 2-arachidonoylglycerol elicited glutamate release through presynaptic transient receptor potential vanilloid 1 (TRPV1) and astrocytic cannabinoid type-1 receptors (CB1Rs) in the NAcore of saline-yoked rats. In rats with a history of cocaine self-administration and extinction training, AEA failed to alter synaptic glutamate release in the NAcore, whereas CB1R-mediated astrocytic glutamate release by AEA remained functional. In order to induce increased astrocytic glutamate release via exogenous AEA, (R)-methanandamide (methAEA, a metabolically stable form of AEA) was chronically infused in the NAcore via osmotic pumps during extinction training. Restoration of mGluR2/3 function and mGluR5-mediated astrocytic glutamate release was observed after chronic methAEA infusion. Additionally, priming or cue-induced reinstatement of cocaine seeking was inhibited in methAEA-infused rats. These results demonstrate that enhancing endocannabinoid signaling is a potential pathway to restore glutamate homeostasis and may represent a promising therapeutic strategy for preventing cocaine relapse.
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Stennett BA, Padovan-Hernandez Y, Knackstedt LA. Sequential cocaine-alcohol self-administration produces adaptations in rat nucleus accumbens core glutamate homeostasis that are distinct from those produced by cocaine self-administration alone. Neuropsychopharmacology 2020; 45:441-450. [PMID: 31266052 PMCID: PMC6969168 DOI: 10.1038/s41386-019-0452-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Revised: 06/07/2019] [Accepted: 06/21/2019] [Indexed: 12/13/2022]
Abstract
There are currently no FDA-approved medications to reduce cocaine relapse. The majority of preclinical studies aimed at identifying the neurobiology underlying relapse involve the self-administration of cocaine alone, whereas many, if not a majority, of cocaine users engage in polysubstance use. Here we developed a rat model of sequential cocaine and alcohol self-administration to test the hypothesis that this combination produces distinct neuroadaptations relative to those produced by cocaine alone. Male rats underwent intravenous cocaine self-administration (2 h/day) followed by 6 h access to unsweetened alcohol (20% v/v) for 12 days. After extinction training, we assessed surface expression of the glutamate transporter GLT-1 and glutamate efflux in the nucleus accumbens (NA) core during the reinstatement of cocaine-seeking. We also tested the ability of ceftriaxone to attenuate the reinstatement of cocaine-seeking and assessed reinstatement-induced Fos expression in several regions critical for reinstatement. Alcohol consumption did not alter cocaine intake, nor did access to cocaine alter alcohol consumption. However, we noted significant changes in glutamate homeostasis in the NA core of cocaine + alcohol rats relative to rats consuming cocaine alone, such as increased surface GLT-1 expression and a lack of increase in glutamate efflux during reinstatement of cocaine-seeking. A history of cocaine + alcohol also altered patterns of reinstatement-induced Fos expression. These changes likely account for the inability of ceftriaxone to attenuate cocaine relapse in cocaine + alcohol rats, while it does so in rats consuming only cocaine. As such glutamate neuroadaptations are targeted by medications to reduce cocaine relapse, preclinical models should consider polysubstance use.
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Affiliation(s)
- Bethany A Stennett
- Psychology Department, University of Florida, Gainesville, FL, USA
- Center for Addiction Research, University of Florida, Gainesville, FL, USA
| | - Yasmin Padovan-Hernandez
- Psychology Department, University of Florida, Gainesville, FL, USA
- Center for Addiction Research, University of Florida, Gainesville, FL, USA
| | - Lori A Knackstedt
- Psychology Department, University of Florida, Gainesville, FL, USA.
- Center for Addiction Research, University of Florida, Gainesville, FL, USA.
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Niedzielska-Andres E, Mizera J, Sadakierska-Chudy A, Pomierny-Chamioło L, Filip M. Changes in the glutamate biomarker expression in rats vulnerable or resistant to the rewarding effects of cocaine and their reversal by ceftriaxone. Behav Brain Res 2019; 370:111945. [DOI: 10.1016/j.bbr.2019.111945] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Revised: 05/11/2019] [Accepted: 05/13/2019] [Indexed: 02/06/2023]
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Li X, Peng XQ, Jordan CJ, Li J, Bi GH, He Y, Yang HJ, Zhang HY, Gardner EL, Xi ZX. mGluR5 antagonism inhibits cocaine reinforcement and relapse by elevation of extracellular glutamate in the nucleus accumbens via a CB1 receptor mechanism. Sci Rep 2018; 8:3686. [PMID: 29487381 PMCID: PMC5829076 DOI: 10.1038/s41598-018-22087-1] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 02/16/2018] [Indexed: 12/02/2022] Open
Abstract
Metabotropic glutamate receptor 5 (mGluR5) antagonism inhibits cocaine self-administration and reinstatement of drug-seeking behavior. However, the cellular and molecular mechanisms underlying this action are poorly understood. Here we report a presynaptic glutamate/cannabinoid mechanism that may underlie this action. Systemic or intra-nucleus accumbens (NAc) administration of the mGluR5 antagonist 2-methyl-6-(phenylethynyl)-pyridine (MPEP) dose-dependently reduced cocaine (and sucrose) self-administration and cocaine-induced reinstatement of drug-seeking behavior. The reduction in cocaine-taking and cocaine-seeking was associated with a reduction in cocaine-enhanced extracellular glutamate, but not cocaine-enhanced extracellular dopamine (DA) in the NAc. MPEP alone, when administered systemically or locally into the NAc, elevated extracellular glutamate, but not DA. Similarly, the cannabinoid CB1 receptor antagonist, rimonabant, elevated NAc glutamate, not DA. mGluR5s were found mainly in striatal medium-spiny neurons, not in astrocytes, and MPEP-enhanced extracellular glutamate was blocked by a NAc CB1 receptor antagonist or N-type Ca++ channel blocker, suggesting that a retrograde endocannabinoid-signaling mechanism underlies MPEP-induced glutamate release. This interpretation was further supported by our findings that genetic deletion of CB1 receptors in CB1-knockout mice blocked both MPEP-enhanced extracellular glutamate and MPEP-induced reductions in cocaine self-administration. Together, these results indicate that the therapeutic anti-cocaine effects of mGluR5 antagonists are mediated by elevation of extracellular glutamate in the NAc via an endocannabinoid-CB1 receptor disinhibition mechanism.
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Affiliation(s)
- Xia Li
- Department of Psychiatry, School of Medicine, University of California San Diego, La Jolla, CA, 92093, USA. .,Molecular Targets and Medications Discovery Branch, Intramural Research Program, National Institute on Drug Abuse, Baltimore, MD, 21224, USA.
| | - Xiao-Qing Peng
- Molecular Targets and Medications Discovery Branch, Intramural Research Program, National Institute on Drug Abuse, Baltimore, MD, 21224, USA.,Psychiatry Residency Training Program, Department of Behavioral Health, Saint Elizabeths Hospital, 1100 Alabama Ave. SE, Washington, DC, 20032, USA
| | - Chloe J Jordan
- Molecular Targets and Medications Discovery Branch, Intramural Research Program, National Institute on Drug Abuse, Baltimore, MD, 21224, USA
| | - Jie Li
- Department of Psychiatry, School of Medicine, University of California San Diego, La Jolla, CA, 92093, USA.,Molecular Targets and Medications Discovery Branch, Intramural Research Program, National Institute on Drug Abuse, Baltimore, MD, 21224, USA
| | - Guo-Hua Bi
- Molecular Targets and Medications Discovery Branch, Intramural Research Program, National Institute on Drug Abuse, Baltimore, MD, 21224, USA
| | - Yi He
- Molecular Targets and Medications Discovery Branch, Intramural Research Program, National Institute on Drug Abuse, Baltimore, MD, 21224, USA
| | - Hong-Ju Yang
- Molecular Targets and Medications Discovery Branch, Intramural Research Program, National Institute on Drug Abuse, Baltimore, MD, 21224, USA
| | - Hai-Ying Zhang
- Molecular Targets and Medications Discovery Branch, Intramural Research Program, National Institute on Drug Abuse, Baltimore, MD, 21224, USA
| | - Eliot L Gardner
- Molecular Targets and Medications Discovery Branch, Intramural Research Program, National Institute on Drug Abuse, Baltimore, MD, 21224, USA
| | - Zheng-Xiong Xi
- Molecular Targets and Medications Discovery Branch, Intramural Research Program, National Institute on Drug Abuse, Baltimore, MD, 21224, USA.
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Extracellular Glutamate in the Nucleus Accumbens Is Nanomolar in Both Synaptic and Non-synaptic Compartments. Cell Rep 2017; 18:2576-2583. [PMID: 28297662 DOI: 10.1016/j.celrep.2017.02.047] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 01/26/2017] [Accepted: 02/15/2017] [Indexed: 12/25/2022] Open
Abstract
In the CNS, glutamate is both phasically and tonically released into the extracellular space and must be removed by excitatory amino acid transporters (EAATs) to prevent excitotoxic accumulation. There remains uncertainty, however, regarding the functional steady-state concentration, with estimates ranging from tens of nanomolar to tens of micromolar. Efforts to reconcile these disparate values have led to a hypothesis that the extracellular space comprises distinct compartments in which basal glutamate concentrations are maintained independently. We used electrophysiology and two-photon Ca2+ imaging to test this hypothesis in the nucleus accumbens (NAc), where it has been proposed that micromolar extracellular glutamate is necessary for normal function. We found that the average concentration of synaptic glutamate is nanomolar, in agreement with previous electrophysiological estimates. Furthermore, this held true when glutamate uptake was inhibited, indicating that extracellular glutamate is not compartmentalized by EAATs.
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Pomierny-Chamiolo L, Miszkiel J, Frankowska M, Mizera J, Filip M. Neuroadaptive changes in metabotropic glutamate mGlu2/3R expression during different phases of cocaine addiction in rats. Pharmacol Rep 2017; 69:1073-1081. [DOI: 10.1016/j.pharep.2017.04.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2017] [Revised: 04/05/2017] [Accepted: 04/20/2017] [Indexed: 12/30/2022]
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Liu XL, Li L, Li JN, Tang JH, Rong JH, Liu B, Hu ZX. Quantifying absolute glutamate concentrations in nucleus accumbens of prescription opioid addicts by using 1H MRS. Brain Behav 2017; 7:e00769. [PMID: 28828225 PMCID: PMC5561325 DOI: 10.1002/brb3.769] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 06/07/2017] [Accepted: 06/13/2017] [Indexed: 02/06/2023] Open
Abstract
INTRODUCTION The diagnosis of psychoactive substance use disorders has been based primarily on descriptive, symptomatic checklist criteria. In opioid addiction, there are no objective biological indicators specific enough to guide diagnosis, monitor disease status, and evaluate efficacy of therapeutic interventions. Proton magnetic resonance spectroscopy (1H MRS) of the brain has potential to identify and quantify biomarkers for the diagnosis of opioid dependence. The purpose of this study was to detect the absolute glutamate concentration in the nucleus accumbens (NAc) of patients with prescription opioid dependence using 1H MRS, and to analyze its clinical associations. METHODS Twenty patients with clinically diagnosed definitive prescription opioid dependent (mean age = 26.5 ± 4.3 years) and 20 matched healthy controls (mean age = 26.1 ± 3.8 years) participated in this study. Patients were evaluated with the Barratt Impulsiveness Scale (BIS-11), the Self-Rating Anxiety Scale (SAS), and the opiate Addiction Severity Inventory (ASI). We used point-resolved spectroscopy to quantify the absolute concentrations of metabolites (glutamate, choline, N-acetylaspartate, glutamine, creatine) within the NAc. The difference between metabolite levels of groups and Pearson's correlation between glutamate levels and psychometric scores in patients were analyzed statistically. RESULTS Glutamate concentrations in the NAc were significantly higher in prescription opiate addicts than in controls (t = 3.84, p = .001). None of the other metabolites differed significantly between the two groups (all ps > .05). The glutamate concentrations correlated positively with BIS-11 scores in prescription opiate addicts (r = .671, p = .001), but not with SAS score and ASI index. CONCLUSIONS Glutamate levels in the NAc measured quantitatively with in vivo 1H MRS could be used as a biomarker to evaluate disease condition in opioid-dependent patients.
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Affiliation(s)
- Xi-Long Liu
- Department of Radiology Guangdong Provincial Corps Hospital of Chinese People's Armed Police Forces Guangzhou Medical University Guangzhou China
| | - Long Li
- Department of Radiology Guangdong Provincial Corps Hospital of Chinese People's Armed Police Forces Guangzhou Medical University Guangzhou China
| | - Jian-Neng Li
- Department of Radiology Guangdong Provincial Corps Hospital of Chinese People's Armed Police Forces Guangzhou Medical University Guangzhou China
| | - Ji-Hua Tang
- Department of Psychology and Addiction Medicine Guangdong Provincial Corps Hospital of Chinese People's Armed Police Forces Guangzhou Medical University Guangzhou China
| | - Jia-Hui Rong
- Department of Radiology Guangdong Provincial Corps Hospital of Chinese People's Armed Police Forces Guangzhou Medical University Guangzhou China
| | - Bo Liu
- Department of Radiology Guangdong Provincial Corps Hospital of Chinese People's Armed Police Forces Guangzhou Medical University Guangzhou China
| | - Ze-Xuan Hu
- Department of Radiology Guangdong Provincial Corps Hospital of Chinese People's Armed Police Forces Guangzhou Medical University Guangzhou China
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Pomierny-Chamiolo L, Miszkiel J, Frankowska M, Bystrowska B, Filip M. Cocaine self-administration, extinction training and drug-induced relapse change metabotropic glutamate mGlu5 receptors expression: Evidence from radioligand binding and immunohistochemistry assays. Brain Res 2016; 1655:66-76. [PMID: 27871824 DOI: 10.1016/j.brainres.2016.11.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Revised: 10/28/2016] [Accepted: 11/11/2016] [Indexed: 12/24/2022]
Abstract
Several behavioral findings highlight the importance of glutamatergic transmission and its metabotropic receptor type 5 (mGlu5) in the controlling of cocaine reward and seeking behaviors. The molecular or neurochemical nature of such interactions is not well recognized, so in the present paper we determine if cocaine self-administration and extinction/reinstatement models with the yoked triad control procedure alter mGlu5 receptor density in rats. [³H]MPEP was used to evaluate mGlu5 receptors density and affinity in selected brain structures, while immunofluorescence analysis was used to detect changes in mGlu5 receptors' brain location. Cocaine self-administration and yoked cocaine delivery evoked a significant elevation in mGlu5 receptors' density in the dorsal striatum, while receptor protein expression was importantly elevated in the substantia nigra and reduced in the nucleus accumbens shell. Cocaine administration followed by 10 extinction training sessions resulted in biphasic mGlu5 receptor density changes in the prefrontal cortex-nucleus accumbens pathway. mGlu5 receptors' up-regulation was noted for cocaine self-administration and extinction training in the hippocampus and in yoked cocaine controls following drug abstinence in the dorsal striatum. A cocaine priming dose (but not a saline priming) resulted in a significant decrease of mGlu5 receptors' density in the nucleus accumbens of rats previously treated with the drug and in the hippocampus of rats previously self-administered cocaine. The latter decrease in mGlu5 receptors' density and protein expression in the hippocampus was parallel to an increase in [³H]MPEP affinity and opposite to a rise observed after single cocaine administration (ip) to drug-naïve yoked saline controls. Additionally, we also observed a significant elevation in the protein expression of the tested receptors in the limbic cortex in both cocaine groups. The present results shown modality dependent and brain-region specific changes in mGlu5 receptors' localization and membrane specific binding.
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Affiliation(s)
- Lucyna Pomierny-Chamiolo
- Department of Toxicology, Faculty of Pharmacy, Jagiellonian University, Medical College, Medyczna 9, PL 30-688 Kraków, Poland.
| | - Joanna Miszkiel
- Institute of Pharmacology Polish Academy of Sciences, Laboratory of Drug Addiction Pharmacology, Smętna 12, PL 31-343 Kraków, Poland
| | - Malgorzata Frankowska
- Institute of Pharmacology Polish Academy of Sciences, Laboratory of Drug Addiction Pharmacology, Smętna 12, PL 31-343 Kraków, Poland
| | - Beata Bystrowska
- Department of Toxicology, Faculty of Pharmacy, Jagiellonian University, Medical College, Medyczna 9, PL 30-688 Kraków, Poland
| | - Malgorzata Filip
- Institute of Pharmacology Polish Academy of Sciences, Laboratory of Drug Addiction Pharmacology, Smętna 12, PL 31-343 Kraków, Poland
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Zhou L, Andersen H, Arreola AC, Turner JR, Ortinski PI. Behavioral History of Withdrawal Influences Regulation of Cocaine Seeking by Glutamate Re-Uptake. PLoS One 2016; 11:e0163784. [PMID: 27685834 PMCID: PMC5042528 DOI: 10.1371/journal.pone.0163784] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Accepted: 09/14/2016] [Indexed: 11/17/2022] Open
Abstract
Withdrawal from cocaine regulates expression of distinct glutamate re-uptake transporters in the nucleus accumbens (NAc). In this study, we examined the cumulative effect of glutamate re-uptake by multiple excitatory amino acid transporters (EAATs) on drug-seeking at two different stages of withdrawal from self-administered cocaine. Rats were trained on fixed ratio 1 (FR1), progressing to FR5 schedule of reinforcement. After one day of withdrawal, microinfusion of a broad non-transportable EAAT antagonist, DL-threo-beta-benzyloxyaspartate (DL-TBOA), into the NAc shell dose-dependently attenuated self-administration of cocaine. Sucrose self-administration was not affected by DL-TBOA, indicating an effect specific to reinforcing properties of cocaine. The attenuating effect on cocaine seeking was not due to suppression of locomotor response, as DL-TBOA was found to transiently increase spontaneous locomotor activity. Previous studies have established a role for EAAT2-mediated re-uptake on reinstatement of cocaine seeking following extended withdrawal and extinction training. We found that blockade of NAc shell EAATs did not affect cocaine-primed reinstatement of cocaine seeking. These results indicate that behavioral history of withdrawal influences the effect of re-uptake mediated glutamate clearance on cocaine seeking. Dynamic regulation of glutamate availability by re-uptake mechanisms may impact other glutamate signaling pathways to account for such differences.
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Affiliation(s)
- Luyi Zhou
- Department of Pharmacology, Physiology, and Neuroscience, University of South Carolina School of Medicine, Columbia, SC, 29208, United States of America.,South Carolina College of Pharmacy, Department of Drug Discovery and Biomedical Sciences, University of South Carolina, Columbia, SC, 29208, United States of America
| | - Haley Andersen
- Department of Pharmacology, Physiology, and Neuroscience, University of South Carolina School of Medicine, Columbia, SC, 29208, United States of America
| | - Adrian C Arreola
- Center for Neurobiology and Behavior, Department of Psychiatry, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, 19104, United States of America
| | - Jill R Turner
- South Carolina College of Pharmacy, Department of Drug Discovery and Biomedical Sciences, University of South Carolina, Columbia, SC, 29208, United States of America
| | - Pavel I Ortinski
- Department of Pharmacology, Physiology, and Neuroscience, University of South Carolina School of Medicine, Columbia, SC, 29208, United States of America
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N-acetylcysteine amide (AD4) reduces cocaine-induced reinstatement. Psychopharmacology (Berl) 2016; 233:3437-48. [PMID: 27469021 DOI: 10.1007/s00213-016-4388-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Accepted: 07/12/2016] [Indexed: 02/07/2023]
Abstract
RATIONALE Chronic exposure to drugs of abuse changes glutamatergic transmission in human addicts and animal models. N-acetylcysteine (NAC) is a cysteine prodrug that indirectly activates cysteine-glutamate antiporters. In the extrasynaptic space, NAC restores basal glutamate levels during drug abstinence and normalizes increased glutamatergic tone in rats during reinstatement to drugs of abuse. In initial clinical trials, repeated NAC administration seems to be promising for reduced craving in cocaine addicts. OBJECTIVE In this study, NAC-amide, called AD4 or NACA, was examined in intravenous cocaine self-administration and extinction/reinstatement procedures in rats. We investigated the behavioral effects of AD4 in the olfactory bulbectomized (OBX) rats, considered an animal model of depression. Finally, we tested rats injected with AD4 or NAC during 10-daily extinction training sessions to examine subsequent cocaine seeking. RESULTS AD4 (25-75 mg kg(-1)) given acutely did not alter the rewarding effects of cocaine in OBX rats and sham-operated controls. However, at 6.25-50 mg kg(-1), AD4 decreased dose-dependently cocaine seeking and relapse triggered by cocaine priming or drug-associated conditioned cues in both phenotypes. Furthermore, repeated treatment with AD4 (25 mg kg(-1)) or NAC (100 mg kg(-1)) during daily extinction trials reduced reinstatement of drug-seeking behavior in sham-operated controls. In the OBX rats only, AD4 effectively blocked cocaine-seeking behavior. CONCLUSIONS Our results demonstrate that AD4 is effective at blocking cocaine-seeking behavior, highlighting its potential clinical use toward cocaine use disorder.
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D'Souza MS. Glutamatergic transmission in drug reward: implications for drug addiction. Front Neurosci 2015; 9:404. [PMID: 26594139 PMCID: PMC4633516 DOI: 10.3389/fnins.2015.00404] [Citation(s) in RCA: 84] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Accepted: 10/12/2015] [Indexed: 12/12/2022] Open
Abstract
Individuals addicted to drugs of abuse such as alcohol, nicotine, cocaine, and heroin are a significant burden on healthcare systems all over the world. The positive reinforcing (rewarding) effects of the above mentioned drugs play a major role in the initiation and maintenance of the drug-taking habit. Thus, understanding the neurochemical mechanisms underlying the reinforcing effects of drugs of abuse is critical to reducing the burden of drug addiction in society. Over the last two decades, there has been an increasing focus on the role of the excitatory neurotransmitter glutamate in drug addiction. In this review, pharmacological and genetic evidence supporting the role of glutamate in mediating the rewarding effects of the above described drugs of abuse will be discussed. Further, the review will discuss the role of glutamate transmission in two complex heterogeneous brain regions, namely the nucleus accumbens (NAcc) and the ventral tegmental area (VTA), which mediate the rewarding effects of drugs of abuse. In addition, several medications approved by the Food and Drug Administration that act by blocking glutamate transmission will be discussed in the context of drug reward. Finally, this review will discuss future studies needed to address currently unanswered gaps in knowledge, which will further elucidate the role of glutamate in the rewarding effects of drugs of abuse.
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Affiliation(s)
- Manoranjan S D'Souza
- Pharmaceutical and Biomedical Sciences, Raabe College of Pharmacy, Ohio Northern University Ada, OH, USA
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Abstract
Drug withdrawal is often conceptualized as an aversive state that motivates drug-seeking and drug-taking behaviors in humans. Stress is more difficult to define, but is also frequently associated with aversive states. Here we describe evidence for the simple theory that drug withdrawal is a stress-like state, on the basis of common effects on behavioral, neurochemical, and molecular endpoints. We also describe data suggesting a more complex relationship between drug withdrawal and stress. As one example, we will highlight evidence that, depending on drug class, components of withdrawal can produce effects that have characteristics consistent with mood elevation. In addition, some stressors can act as positive reinforcers, defined as having the ability to increase the probability of a behavior that produces it. As such, accumulating evidence supports the general principles of opponent process theory, whereby processes that have an affective valence are followed in time by an opponent process that has the opposite valence. Throughout, we identify gaps in knowledge and propose future directions for research. A better understanding of the similarities, differences, and overlaps between drug withdrawal and stress will lead to the development of improved treatments for addiction, as well as for a vast array of neuropsychiatric conditions that are triggered or exacerbated by stress.
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McIntosh S, Sexton T, Pattison LP, Childers SR, Hemby SE. Increased Sensitivity to Cocaine Self-Administration in HIV-1 Transgenic Rats is Associated with Changes in Striatal Dopamine Transporter Binding. J Neuroimmune Pharmacol 2015; 10:493-505. [PMID: 25749646 DOI: 10.1007/s11481-015-9594-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Accepted: 02/13/2015] [Indexed: 12/14/2022]
Abstract
Cocaine abuse in HIV patients accelerates the progression and severity of neuropathology, motor impairment and cognitive dysfunction compared to non-drug using HIV patients. Cocaine and HIV interact with the dopamine transporter (DAT); however, the effect of their interaction on DAT binding remains understudied. The present study compared the dose-response functions for intravenous self-administration of cocaine and heroin between male HIV-1 transgenic (HIV-1 Tg) and Fischer 344 rats. The cocaine and heroin dose-response functions exhibit an inverted U-shape for both HIV-1 Tg and F344 rats. For cocaine, the number of infusions for each dose on the ascending limb was greater for HIV-1 Tg versus F344 rats. No significant changes in the heroin dose-response function were observed in HIV-1 Tg animals. Following the conclusion of self-administration experiments, DAT binding was assessed in striatal membranes. Saturation binding of the cocaine analog [(125)I] 3β-(4-iodophenyl)tropan-2β-carboxylic acid methyl ester ([(125)I]RTI-55) in rat striatal membranes resulted in binding curves that were best fit to a two-site binding model, allowing for calculation of dissociation constant (Kd) and binding density (Bmax) values that correspond to high- and low-affinity DAT binding sites. Control HIV-1 Tg rats exhibited a significantly greater affinity (i.e., decrease in Kd value) in the low-affinity DAT binding site compared to control F344 rats. Furthermore, cocaine self-administration in HIV-1 Tg rats increased low-affinity Kd (i.e., decreased affinity) compared to levels observed in control F344 rats. Cocaine also increased low-affinity Bmax in HIV-1 Tg rats as compared to controls, indicating an increase in the number of low-affinity DAT binding sites. F344 rats did not exhibit any change in high- or low-affinity Kd or Bmax values following cocaine or heroin self-administration. The increase in DAT affinity in cocaine HIV-1 Tg rats is consistent with the leftward shift of the ascending limb of the cocaine dose-response curve observed in HIV-1 Tg vs. F344 rats, and has major implications for the function of cocaine binding to DAT in HIV patients. The absence of HIV-related changes in heroin intake are likely due to less dopaminergic involvement in the mediation of heroin reward, further emphasizing the preferential influence of HIV on dopamine-related behaviors.
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Affiliation(s)
- Scot McIntosh
- Department of Physiology and Pharmacology, Center for the Neurobiology of Addiction Treatment, Winston-Salem, NC, USA
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Sun WL, Eisenstein SA, Zelek-Molik A, McGinty JF. A single brain-derived neurotrophic factor infusion into the dorsomedial prefrontal cortex attenuates cocaine self-administration-induced phosphorylation of synapsin in the nucleus accumbens during early withdrawal. Int J Neuropsychopharmacol 2015; 18:pyu049. [PMID: 25522393 PMCID: PMC4368877 DOI: 10.1093/ijnp/pyu049] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Dysregulation in the prefrontal cortex-nucleus accumbens pathway has been implicated in cocaine addiction. We have previously demonstrated that one intra-dorsomedial prefrontal cortex brain-derived neurotrophic factor (BDNF) infusion immediately following the last cocaine self-administration session caused a long-lasting inhibition of cocaine-seeking and normalized the cocaine-induced disturbance of glutamate transmission in the nucleus accumbens after extinction and a cocaine prime. However, the molecular mechanism mediating the brain-derived neurotrophic factor effect on cocaine-induced alterations in extracellular glutamate levels is unknown. METHODS In the present study, we determined the effects of brain-derived neurotrophic factor on cocaine-induced changes in the phosphorylation of synapsin (p-synapsin), a family of presynaptic proteins that mediate synaptic vesicle mobilization, in the nucleus accumbens during early withdrawal. RESULTS Two hours after cocaine self-administration, p-synapsin Ser9 and p-synapsin Ser62/67, but not p-synapsin Ser603, were increased in the nucleus accumbens. At 22 hours, only p-synapsin Ser9 was still elevated. Elevations at both time points were attenuated by an intra-dorsomedial prefrontal cortex brain-derived neurotrophic factor infusion immediately after the end of cocaine self-administration. Brain-derived neurotrophic factor also reduced cocaine self-administration withdrawal-induced phosphorylation of the protein phosphatase 2A C-subunit, suggesting that brain-derived neurotrophic factor disinhibits protein phosphatase 2A C-subunit, consistent with p-synapsin Ser9 dephosphorylation. Further, co-immunoprecipitation demonstrated that protein phosphatase 2A C-subunit and synapsin are associated in a protein-protein complex that was reduced after 2 hours of withdrawal from cocaine self-administration and reversed by brain-derived neurotrophic factor. CONCLUSIONS Taken together, these findings demonstrate that brain-derived neurotrophic factor normalizes the cocaine self-administration-induced elevation of p-synapsin in nucleus accumbens that may underlie a disturbance in the probability of neurotransmitter release or represent a compensatory neuroadaptation in response to the hypofunction within the prefrontal cortex-nucleus accumbens pathway during cocaine withdrawal.
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Affiliation(s)
- Wei-Lun Sun
- Department of Neurosciences and Neurobiology of Addiction Research Center, Medical University of South Carolina, Charleston, South Carolina, (Drs Sun and McGinty); Department of Psychiatry, Washington University, St Louis, MO (Dr Eisenstein); Department of Brain Biochemistry, Institute of Pharmacology, Polish Academy of Sciences, Krakow, Poland (Dr Zelek-Molik)
| | - Sarah A Eisenstein
- Department of Neurosciences and Neurobiology of Addiction Research Center, Medical University of South Carolina, Charleston, South Carolina, (Drs Sun and McGinty); Department of Psychiatry, Washington University, St Louis, MO (Dr Eisenstein); Department of Brain Biochemistry, Institute of Pharmacology, Polish Academy of Sciences, Krakow, Poland (Dr Zelek-Molik)
| | - Agnieszka Zelek-Molik
- Department of Neurosciences and Neurobiology of Addiction Research Center, Medical University of South Carolina, Charleston, South Carolina, (Drs Sun and McGinty); Department of Psychiatry, Washington University, St Louis, MO (Dr Eisenstein); Department of Brain Biochemistry, Institute of Pharmacology, Polish Academy of Sciences, Krakow, Poland (Dr Zelek-Molik)
| | - Jacqueline F McGinty
- Department of Neurosciences and Neurobiology of Addiction Research Center, Medical University of South Carolina, Charleston, South Carolina, (Drs Sun and McGinty); Department of Psychiatry, Washington University, St Louis, MO (Dr Eisenstein); Department of Brain Biochemistry, Institute of Pharmacology, Polish Academy of Sciences, Krakow, Poland (Dr Zelek-Molik).
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Doyle SE, Ramôa C, Garber G, Newman J, Toor S, Lynch WJ. A shift in the role of glutamatergic signaling in the nucleus accumbens core with the development of an addicted phenotype. Biol Psychiatry 2014; 76:810-5. [PMID: 24629536 PMCID: PMC4133320 DOI: 10.1016/j.biopsych.2014.02.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Revised: 02/02/2014] [Accepted: 02/03/2014] [Indexed: 12/19/2022]
Abstract
BACKGROUND While dopamine signaling in the nucleus accumbens (NAc) plays a well-established role in motivating cocaine use in early nonaddicted stages, recent evidence suggests that other signaling pathways may be critical once addiction has developed. Given the importance of glutamatergic signaling in the NAc for drug seeking and relapse, here we examined its role in motivating cocaine self-administration under conditions known to produce either a nonaddicted or an addicted phenotype. METHODS Following acquisition, male and female Sprague Dawley rats were given either short access (three fixed-ratio 1 sessions, 20 infusions/day) or extended 24-hour access (10 days; 4 trials/hour; up to 96 infusions/day) to cocaine. Following a 14-day abstinence period, motivation for cocaine was assessed under a progressive-ratio schedule, and once stable, the effects of intra-NAc infusions of the glutamate alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate/kainate receptor antagonist CNQX (0, .01, .03, .1 μg/side) were determined. As an additional measure for the development of an addicted phenotype, separate groups of rats were screened under an extinction/cue-induced reinstatement procedure following abstinence from short-access versus extended-access self-administration. RESULTS Motivation for cocaine and levels of extinction and reinstatement responding were markedly higher following extended-access versus short-access self-administration, confirming the development of an addicted phenotype in the extended-access group. CNQX dose-dependently reduced motivation for cocaine in the extended-access group but was without effect in the short-access group. CONCLUSIONS These results suggest that the role of glutamatergic signaling in the NAc, though not essential for motivating cocaine use in nonaddicted stages, becomes critical once addiction has developed.
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McGinty JF, Zelek-Molik A, Sun WL. Cocaine self-administration causes signaling deficits in corticostriatal circuitry that are reversed by BDNF in early withdrawal. Brain Res 2014; 1628:82-7. [PMID: 25268928 DOI: 10.1016/j.brainres.2014.09.050] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Revised: 09/16/2014] [Accepted: 09/20/2014] [Indexed: 01/05/2023]
Abstract
Cocaine self-administration disturbs intracellular signaling in prefrontal cortical neurons that regulate neurotransmission in the nucleus accumbens. The deficits in dorsomedial prefrontal cortex (dmPFC) signaling change over time, resulting in different neuroadaptations during early withdrawal from cocaine self-administration than after one or more weeks of abstinence. Within the first few hours of withdrawal, there is a marked decrease in tyrosine phosphorylation of critical intracellular and membrane-bound proteins in the dmPFC that include ERK/MAP kinase and the NMDA receptor subunits, GluN1 and GluN2B. These changes are accompanied by a marked increase in STEP tyrosine phosphatase activation. Simultaneously, ERK and PKA-dependent synapsin phosphorylation in presynaptic terminals of the nucleus accumbens is increased that may have a destabilizing impact on glutamatergic transmission. Infusion of brain-derived neurotrophic factor (BDNF) into the dmPFC immediately following a final session of cocaine self-administration blocks the cocaine-induced changes in phosphorylation and attenuates relapse to cocaine seeking for as long as three weeks. The intra-dmPFC BDNF infusion also prevents cocaine-induced deficits in prefronto-accumbens glutamatergic transmission that are implicated in cocaine seeking. Thus, intervention with BDNF in the dmPFC during early withdrawal has local and distal effects in target areas that are critical to mediating cocaine-induced neuroadaptations that lead to cocaine seeking.
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Affiliation(s)
- Jacqueline F McGinty
- Department of Neurosciences, Medical University of South Carolina, Charleston, SC 29425, USA.
| | - Agnieska Zelek-Molik
- Department of Neurosciences, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Wei-Lun Sun
- Department of Neurosciences, Medical University of South Carolina, Charleston, SC 29425, USA
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27
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Synapse Density and Dendritic Complexity Are Reduced in the Prefrontal Cortex following Seven Days of Forced Abstinence from Cocaine Self-Administration. PLoS One 2014; 9:e102524. [PMID: 25072653 PMCID: PMC4114454 DOI: 10.1371/journal.pone.0102524] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Accepted: 06/19/2014] [Indexed: 12/03/2022] Open
Abstract
Chronic cocaine exposure in both human addicts and in rodent models of addiction reduces prefrontal cortical activity, which subsequently dysregulates reward processing and higher order executive function. The net effect of this impaired gating of behavior is enhanced vulnerability to relapse. Previously we have shown that cocaine-induced increases in brain-derived neurotrophic factor (BDNF) expression in the medial prefrontal cortex (PFC) is a neuroadaptive mechanism that blunts the reinforcing efficacy of cocaine. As BDNF is known to affect neuronal survival and synaptic plasticity, we tested the hypothesis that abstinence from cocaine self-administration would lead to alterations in neuronal morphology and synaptic density in the PFC. Using a novel technique, array tomography and Golgi staining, morphological changes in the rat PFC were analyzed following 14 days of cocaine self-administration and 7 days of forced abstinence. Our results indicate that overall dendritic branching and total synaptic density are significantly reduced in the rat PFC. In contrast, the density of thin dendritic spines are significantly increased on layer V pyramidal neurons of the PFC. These findings indicate that dynamic structural changes occur during cocaine abstinence that may contribute to the observed hypo-activity of the PFC in cocaine-addicted individuals.
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28
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Lutgen V, Kong L, Kau KS, Madayag A, Mantsch JR, Baker DA. Time course of cocaine-induced behavioral and neurochemical plasticity. Addict Biol 2014; 19:529-38. [PMID: 22970924 PMCID: PMC3525779 DOI: 10.1111/j.1369-1600.2012.00493.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Factors that result in augmented reinstatement, including increased withdrawal period duration and high levels of cocaine consumption, may provide insight into relapse vulnerability. The neural basis of augmented reinstatement may arise from more pronounced changes in plasticity required for reinstatement and/or the emergence of plasticity expressed only during a specific withdrawal period or under specific intake conditions. In this study, we examined the impact of withdrawal period duration and cocaine intake on the magnitude of cocaine-primed reinstatement and extracellular glutamate in the nucleus accumbens, which has been shown to be required for cocaine-primed reinstatement. Rats were assigned to self-administer under conditions resulting in low (2 hours/day; 0.5 mg/kg/infusion, IV) or high (6 hours/day; 1.0 mg/kg/infusion, IV) levels of cocaine intake. After 1, 21 or 60 days of withdrawal, drug seeking and extracellular glutamate levels in the nucleus accumbens were measured before and after a cocaine injection. Cocaine-reinstated lever pressing and elevated extracellular glutamate at every withdrawal time point tested, which is consistent with the conclusion that increased glutamatergic signaling in the nucleus accumbens, is required for cocaine-induced reinstatement. Interestingly, high-intake rats exhibited augmented reinstatement at every time point tested, yet failed to exhibit higher levels of cocaine-induced increases in extracellular glutamate relative to low-intake rats. Our current data indicate that augmented reinstatement in high-intake rats is not due to relative differences in extracellular levels of glutamate in the nucleus accumbens, but rather may stem from intake-dependent plasticity.
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Affiliation(s)
- Victoria Lutgen
- Department of Biomedical Sciences, Marquette University, Suite 446, 561 N. 15 St, Milwaukee, WI 53233
| | - Linghai Kong
- Department of Biomedical Sciences, Marquette University, Suite 446, 561 N. 15 St, Milwaukee, WI 53233
| | - Kristen S. Kau
- Department of Biomedical Sciences, Marquette University, Suite 446, 561 N. 15 St, Milwaukee, WI 53233
| | - Aric Madayag
- Department of Biomedical Sciences, Marquette University, Suite 446, 561 N. 15 St, Milwaukee, WI 53233
| | - John R. Mantsch
- Department of Biomedical Sciences, Marquette University, Suite 446, 561 N. 15 St, Milwaukee, WI 53233
| | - David A. Baker
- Department of Biomedical Sciences, Marquette University, Suite 446, 561 N. 15 St, Milwaukee, WI 53233
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29
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Pomierny-Chamioło L, Rup K, Pomierny B, Niedzielska E, Kalivas PW, Filip M. Metabotropic glutamatergic receptors and their ligands in drug addiction. Pharmacol Ther 2014; 142:281-305. [DOI: 10.1016/j.pharmthera.2013.12.012] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Accepted: 12/02/2013] [Indexed: 02/07/2023]
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30
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Hulka LM, Treyer V, Scheidegger M, Preller KH, Vonmoos M, Baumgartner MR, Johayem A, Ametamey SM, Buck A, Seifritz E, Quednow BB. Smoking but not cocaine use is associated with lower cerebral metabotropic glutamate receptor 5 density in humans. Mol Psychiatry 2014; 19:625-32. [PMID: 23628984 DOI: 10.1038/mp.2013.51] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Accepted: 03/18/2013] [Indexed: 12/18/2022]
Abstract
Long-lasting neuroadaptations in the glutamatergic corticostriatal circuitry have been suggested to be responsible for the persisting nature of drug addiction. In particular, animal models have linked the metabotropic glutamate receptor 5 (mGluR5) to drug-seeking behavior and extinction learning. Accordingly, blocking mGluR5s attenuated self-administration of cocaine and other addictive drugs in rats. How these animal findings extend to humans remains unclear. Therefore, we investigated if human cocaine users (CU) exhibit altered mGluR5 availability compared with drug-naïve control subjects. Seventeen male controls (11 smokers) and 18 male cocaine users (13 smokers) underwent positron emission tomography with (11)C-ABP688 to quantify mGluR5 availability in 12 volumes of interest in addiction-related brain areas. Drug use was assessed by self-report and quantitative hair toxicology. CU and controls did not significantly differ in regional mGluR5 availability. In contrast, smokers (n=24) showed significantly lower mGluR5 density throughout the brain (mean 20%) compared with non-smokers (n=11). In terms of effect sizes, lower mGluR5 availability was most pronounced in the caudate nucleus (d=1.50, 21%), insula (d=1.47, 20%), and putamen (d=1.46, 18%). Duration of smoking abstinence was positively associated with mGluR5 density in all brain regions of interest, indicating that lower mGluR5 availability was particularly pronounced in individuals who had smoked very recently. Specifically tobacco smoking was associated with lower mGluR5 availability in both CU and controls, while cocaine use was not linked to detectable mGluR5 alterations. These findings have important implications regarding the development of novel pharmacotherapies aimed at facilitating smoking cessation.
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Affiliation(s)
- L M Hulka
- Experimental and Clinical Pharmacopsychology, University Hospital of Psychiatry Zurich, Zurich, Switzerland
| | - V Treyer
- Division of Nuclear Medicine, University Hospital Zurich, Zurich, Switzerland
| | - M Scheidegger
- 1] Department of Psychiatry, Psychotherapy, and Psychosomatics, University Hospital of Psychiatry Zurich, Zurich, Switzerland [2] Institute for Biomedical Engineering, University and Swiss Federal Institute of Technology Zurich, Zurich, Switzerland
| | - K H Preller
- Experimental and Clinical Pharmacopsychology, University Hospital of Psychiatry Zurich, Zurich, Switzerland
| | - M Vonmoos
- Experimental and Clinical Pharmacopsychology, University Hospital of Psychiatry Zurich, Zurich, Switzerland
| | - M R Baumgartner
- Institute of Legal Medicine, University of Zurich, Zurich, Switzerland
| | - A Johayem
- Department of Chemistry and Applied Biosciences, Institute of Pharmaceutical Sciences, Swiss Federal Institute of Technology Zurich, University of Zurich, Zurich, Switzerland
| | - S M Ametamey
- 1] Department of Chemistry and Applied Biosciences, Institute of Pharmaceutical Sciences, Swiss Federal Institute of Technology Zurich, University of Zurich, Zurich, Switzerland [2] Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - A Buck
- 1] Division of Nuclear Medicine, University Hospital Zurich, Zurich, Switzerland [2] Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - E Seifritz
- 1] Department of Psychiatry, Psychotherapy, and Psychosomatics, University Hospital of Psychiatry Zurich, Zurich, Switzerland [2] Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - B B Quednow
- 1] Experimental and Clinical Pharmacopsychology, University Hospital of Psychiatry Zurich, Zurich, Switzerland [2] Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
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31
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Keck TM, Zou MF, Bi GH, Zhang HY, Wang XF, Yang HJ, Srivastava R, Gardner EL, Xi ZX, Newman AH. A novel mGluR5 antagonist, MFZ 10-7, inhibits cocaine-taking and cocaine-seeking behavior in rats. Addict Biol 2014; 19:195-209. [PMID: 24001208 DOI: 10.1111/adb.12086] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Pre-clinical studies suggest that negative allosteric modulators (NAMs) of the metabotropic glutamate receptor subtype 5 (mGluR5), including 2-methyl-6-(phenylethynyl)pyridine (MPEP), 3-[(2-methyl-1,3-thiazol-4-yl)ethynyl]pyridine (MTEP) and fenobam are highly effective in attenuating drug-taking and drug-seeking behaviors. However, both MPEP and MTEP have no translational potential for use in humans because of their off-target effects and short half-lives. Here, we report that 3-fluoro-5-[(6-methylpyridin-2-yl)ethynyl]benzonitrile (MFZ 10-7), a novel mGluR5 NAM, is more potent and selective than MPEP, MTEP and fenobam in both in vitro binding and functional assays. Similar to MTEP, intraperitoneal administration of MFZ 10-7 inhibited intravenous cocaine self-administration, cocaine-induced reinstatement of drug-seeking behavior and cocaine-associated cue-induced cocaine-seeking behavior in rats. Although MFZ 10-7 and MTEP lowered the rate of oral sucrose self-administration, they did not alter total sucrose intake. Further, MFZ 10-7 appeared to be more potent than MTEP in inducing downward shifts in the cocaine dose-response curve, but less effective than MTEP in attenuating sucrose-induced reinstatement of sucrose-seeking behavior. MFZ 10-7 and MTEP had no effect on basal locomotor behavior. These findings not only provide additional evidence supporting an important role for mGluR5 in cocaine reward and addiction, but also introduce a new tool for both in vitro and in vivo investigations with which to further characterize this role.
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Affiliation(s)
- Thomas M. Keck
- Medicinal Chemistry Section; Molecular Targets and Medications Discovery Branch; National Institute on Drug Abuse. NIH, DHHS; Baltimore MD USA
| | - Mu-Fa Zou
- Medicinal Chemistry Section; Molecular Targets and Medications Discovery Branch; National Institute on Drug Abuse. NIH, DHHS; Baltimore MD USA
| | - Guo-Hua Bi
- Neuropsychopharmacology Section; Chemical Biology Research Branch; Intramural Research Program; National Institute on Drug Abuse. NIH, DHHS; Baltimore MD USA
| | - Hai-Ying Zhang
- Neuropsychopharmacology Section; Chemical Biology Research Branch; Intramural Research Program; National Institute on Drug Abuse. NIH, DHHS; Baltimore MD USA
| | - Xiao-Fei Wang
- Neuropsychopharmacology Section; Chemical Biology Research Branch; Intramural Research Program; National Institute on Drug Abuse. NIH, DHHS; Baltimore MD USA
| | - Hong-Ju Yang
- Neuropsychopharmacology Section; Chemical Biology Research Branch; Intramural Research Program; National Institute on Drug Abuse. NIH, DHHS; Baltimore MD USA
| | - Ratika Srivastava
- Neuropsychopharmacology Section; Chemical Biology Research Branch; Intramural Research Program; National Institute on Drug Abuse. NIH, DHHS; Baltimore MD USA
| | - Eliot L. Gardner
- Neuropsychopharmacology Section; Chemical Biology Research Branch; Intramural Research Program; National Institute on Drug Abuse. NIH, DHHS; Baltimore MD USA
| | - Zheng-Xiong Xi
- Neuropsychopharmacology Section; Chemical Biology Research Branch; Intramural Research Program; National Institute on Drug Abuse. NIH, DHHS; Baltimore MD USA
| | - Amy Hauck Newman
- Medicinal Chemistry Section; Molecular Targets and Medications Discovery Branch; National Institute on Drug Abuse. NIH, DHHS; Baltimore MD USA
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Martinez D, Slifstein M, Nabulsi N, Grassetti A, Urban N, Perez A, Liu F, Lin SF, Ropchan J, Mao X, Kegeles LS, Shungu DC, Carson RE, Huang Y. Imaging glutamate homeostasis in cocaine addiction with the metabotropic glutamate receptor 5 positron emission tomography radiotracer [(11)C]ABP688 and magnetic resonance spectroscopy. Biol Psychiatry 2014; 75:165-71. [PMID: 24035345 PMCID: PMC4106018 DOI: 10.1016/j.biopsych.2013.06.026] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Revised: 06/05/2013] [Accepted: 06/28/2013] [Indexed: 12/22/2022]
Abstract
BACKGROUND Preclinical studies demonstrate that glutamate homeostasis in the striatum is disrupted following cocaine exposure, including a decrease in metabotropic glutamate receptor type 5 (mGluR5) expression and reduced glutamate turnover. The goal of this study was to use imaging of the human brain to investigate alterations in the glutamate signaling in cocaine addiction. METHODS Positron emission tomography imaging with the radiotracer [(11)C]ABP688 was used to measure mGluR5 binding and magnetic resonance spectroscopy was used to measure glutamate-glutamine levels in the striatum of cocaine-addicted participants (n = 15) compared with healthy control subjects (n = 15). Following the scans, the cocaine-addicted volunteers performed cocaine self-administration sessions to investigate the correlation between cocaine-seeking behavior and mGluR5 receptor binding. RESULTS The results of the study showed that cocaine addiction was associated with a 20% to 22% reduction in [(11)C]ABP688 binding in the striatum. A secondary analysis of cortical and subcortical regions other than the striatum showed a similar reduction in [(11)C]ABP688 binding, suggesting that the decrease was widespread. No between-group differences were seen in the magnetic resonance spectroscopy measures of glutamate-glutamine in the left striatum. In addition, no correlation was seen between [(11)C]ABP688 binding in the striatum and the choice to self-administer cocaine. CONCLUSIONS Overall, these results show that long-term cocaine use is associated with a decrease in mGluR5 availability compared with matched healthy control subjects and suggests that this receptor may serve as a viable target for treatment development for this disorder.
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Affiliation(s)
- Diana Martinez
- Department of Psychiatry, Columbia University College of Physicians and Surgeons and the New York State Psychiatric Institute, New York, New York.
| | - Mark Slifstein
- Department of Psychiatry, Columbia University College of Physicians and Surgeons and the New York State Psychiatric Institute, New York, NY, USA
| | - Nabeel Nabulsi
- The Department of Psychiatry, Yale PET Center, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Alexander Grassetti
- Department of Psychiatry, Columbia University College of Physicians and Surgeons and the New York State Psychiatric Institute, New York, NY, USA
| | - Nina Urban
- Department of Psychiatry, Columbia University College of Physicians and Surgeons and the New York State Psychiatric Institute, New York, NY, USA
| | - Audrey Perez
- Department of Psychiatry, Columbia University College of Physicians and Surgeons and the New York State Psychiatric Institute, New York, NY, USA
| | - Fei Liu
- Department of Psychiatry, Columbia University College of Physicians and Surgeons and the New York State Psychiatric Institute, New York, NY, USA
| | - Shu-fei Lin
- The Department of Psychiatry, Yale PET Center, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Jim Ropchan
- The Department of Psychiatry, Yale PET Center, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Xiangling Mao
- Department of Radiology, Weill Medical College of Cornell University, New York, NY, USA
| | - Lawrence S. Kegeles
- Department of Psychiatry, Columbia University College of Physicians and Surgeons and the New York State Psychiatric Institute, New York, NY, USA
| | - Dikoma C. Shungu
- Department of Radiology, Weill Medical College of Cornell University, New York, NY, USA
| | - Richard E. Carson
- The Department of Psychiatry, Yale PET Center, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Yiyun Huang
- The Department of Psychiatry, Yale PET Center, Yale University School of Medicine, New Haven, Connecticut, USA
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Gonçalves J, Baptista S, Silva AP. Psychostimulants and brain dysfunction: a review of the relevant neurotoxic effects. Neuropharmacology 2014; 87:135-49. [PMID: 24440369 DOI: 10.1016/j.neuropharm.2014.01.006] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2013] [Revised: 12/18/2013] [Accepted: 01/06/2014] [Indexed: 12/21/2022]
Abstract
Psychostimulants abuse is a major public concern because is associated with serious health complications, including devastating consequences on the central nervous system (CNS). The neurotoxic effects of these drugs have been extensively studied. Nevertheless, numerous questions and uncertainties remain in our understanding of these toxic events. Thus, the purpose of the present manuscript is to review cellular and molecular mechanisms that might be responsible for brain dysfunction induced by psychostimulants. Topics reviewed include some classical aspects of neurotoxicity, such as monoaminergic system and mitochondrial dysfunction, oxidative stress, excitotoxicity and hyperthermia. Moreover, recent literature has suggested new phenomena regarding the toxic effects of psychostimulants. Thus, we also reviewed the impact of these drugs on neuroinflammatory response, blood-brain barrier (BBB) function and neurogenesis. Assessing the relative importance of these mechanisms on psychostimulants-induced brain dysfunction presents an exciting challenge for future research efforts. This article is part of the Special Issue entitled 'CNS Stimulants'.
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Affiliation(s)
- Joana Gonçalves
- Laboratory of Pharmacology and Experimental Therapeutics, Institute for Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine, University of Coimbra, Azinhaga Santa Comba, Celas, 3000-548 Coimbra Portugal
| | - Sofia Baptista
- Laboratory of Pharmacology and Experimental Therapeutics, Institute for Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine, University of Coimbra, Azinhaga Santa Comba, Celas, 3000-548 Coimbra Portugal
| | - Ana Paula Silva
- Laboratory of Pharmacology and Experimental Therapeutics, Institute for Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine, University of Coimbra, Azinhaga Santa Comba, Celas, 3000-548 Coimbra Portugal.
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Keck TM, Yang HJ, Bi GH, Huang Y, Zhang HY, Srivastava R, Gardner EL, Newman AH, Xi ZX. Fenobam sulfate inhibits cocaine-taking and cocaine-seeking behavior in rats: implications for addiction treatment in humans. Psychopharmacology (Berl) 2013; 229:253-65. [PMID: 23615919 PMCID: PMC4191672 DOI: 10.1007/s00213-013-3106-9] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2012] [Accepted: 03/30/2013] [Indexed: 12/14/2022]
Abstract
RATIONALE The metabotropic glutamate receptor subtype 5 (mGluR5) has been reported to be critically involved in drug reward and addiction. Because the mGluR5 negative allosteric modulators (NAMs) 2-methyl-6-(phenylethynyl)pyridine (MPEP) and 3-((2-methyl-1,3-thiazol-4-yl)ethynyl)pyridine (MTEP) significantly inhibit addictivelike behaviors of cocaine and other drugs of abuse in experimental animals, it has been suggested that mGluR5 NAMs may have translational potential for treatment of addiction in humans. However, neither MPEP nor MTEP have been evaluated in humans due to their off-target actions and rapid metabolism. OBJECTIVES Herein, we evaluate a potential candidate for translational addiction research: a new sulfate salt formulation of fenobam, a selective mGluR5 NAM that has been investigated in humans. RESULTS In rats, fenobam sulfate had superior pharmacokinetics compared to the free base, with improved maximal plasma concentration (C max) and longer half life. Oral (p.o.) administration of fenobam sulfate (30 or 60 mg/kg) inhibited intravenous (i.v.) cocaine self-administration, cocaine-induced reinstatement of drug-seeking behavior, and cocaine-associated cue-induced cocaine-seeking behavior in rats. Fenobam sulfate also inhibited p.o. sucrose self-administration and sucrose-induced reinstatement of sucrose-seeking behavior, but had no effect on locomotion. CONCLUSIONS This study provides additional support for the role of mGluR5 signaling in cocaine addiction and suggests that fenobam sulfate may have translational potential in medication development for the treatment of cocaine addiction in humans.
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Affiliation(s)
- Thomas M. Keck
- Medicinal Chemistry Section, Molecular Targets and Medications Discovery Branch, Intramural Research Program, National Institute on Drug Abuse, NIH, DHHS, Baltimore, MD, USA 21224
| | - Hong-Ju Yang
- Neuropsychopharmacology Section, Chemical Biology Research Branch, Intramural Research Program, National Institute on Drug Abuse, NIH, DHHS, Baltimore, MD, USA 21224
| | - Guo-Hua Bi
- Neuropsychopharmacology Section, Chemical Biology Research Branch, Intramural Research Program, National Institute on Drug Abuse, NIH, DHHS, Baltimore, MD, USA 21224
| | - Yong Huang
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA, USA 94143
| | - Hai-Ying Zhang
- Neuropsychopharmacology Section, Chemical Biology Research Branch, Intramural Research Program, National Institute on Drug Abuse, NIH, DHHS, Baltimore, MD, USA 21224
| | - Ratika Srivastava
- Neuropsychopharmacology Section, Chemical Biology Research Branch, Intramural Research Program, National Institute on Drug Abuse, NIH, DHHS, Baltimore, MD, USA 21224
| | - Eliot L. Gardner
- Neuropsychopharmacology Section, Chemical Biology Research Branch, Intramural Research Program, National Institute on Drug Abuse, NIH, DHHS, Baltimore, MD, USA 21224
| | - Amy Hauck Newman
- Medicinal Chemistry Section, Molecular Targets and Medications Discovery Branch, Intramural Research Program, National Institute on Drug Abuse, NIH, DHHS, Baltimore, MD, USA 21224
- Corresponding authors: Z.-X. Xi – Phone: (443) 740-2517. Fax: (443) 740-2781. ; A. H. Newman – Phone: (443) 740-2887. Fax: (443) 740-2111.
| | - Zheng-Xiong Xi
- Neuropsychopharmacology Section, Chemical Biology Research Branch, Intramural Research Program, National Institute on Drug Abuse, NIH, DHHS, Baltimore, MD, USA 21224
- Corresponding authors: Z.-X. Xi – Phone: (443) 740-2517. Fax: (443) 740-2781. ; A. H. Newman – Phone: (443) 740-2887. Fax: (443) 740-2111.
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Extrasynaptic targeting of NMDA receptors following D1 dopamine receptor activation and cocaine self-administration. J Neurosci 2013; 33:9451-61. [PMID: 23719812 DOI: 10.1523/jneurosci.5730-12.2013] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
We previously showed that after repeated exposure to cocaine, D1-like dopamine receptor (D1DR) stimulation reverses plastic changes of AMPA receptor-mediated signaling in the nucleus accumbens shell. However, there is little information on the impact of cocaine self-administration on D1-NMDA receptor interactions in this brain region. Here, using whole-cell patch-clamp recordings, we assessed whether cocaine self-administration alters the effects of D1DR stimulation on synaptic and extrasynaptic NMDA receptors (NMDARs). In slices from cocaine-naive rats, pretreatment with a D1DR agonist decreased synaptic NMDAR-mediated currents and increased the contribution of extrasynaptic NMDARs. In contrast, neither cocaine self-administration alone nor cocaine experience followed by D1DR stimulation had an effect on synaptic or extrasynaptic NMDAR signaling. Activation of extrasynaptic NMDARs relies on the availability of extracellular glutamate, which is regulated primarily by glutamate transporters. In cocaine-experienced animals, relative to cocaine-naive rats, administration of a glutamate reuptake blocker, DL-threo-β-benzyloxyaspartic acid, revealed increased extrasynaptic NMDAR activity and stronger baseline activity of glutamate uptake transporters. In cocaine-naive rats, the D1DR-mediated increase in extrasynaptic NMDAR signaling was independent of the activity of glutamate reuptake transporters. Together, these results indicate that cocaine experience blunts the influence of D1DRs on synaptic and extrasynaptic NMDAR signaling. Additionally, prior cocaine self-administration limits activation of the extrasynaptic NMDAR pool by increasing glutamate reuptake. These findings outline a pattern of adaptive interactions between D1DRs and NMDARs in the nucleus accumbens shell and demonstrate upregulation of extrasynaptic NMDAR signaling as a novel consequence of cocaine self-administration.
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Miguéns M, Botreau F, Olías O, Del Olmo N, Coria SM, Higuera-Matas A, Ambrosio E. Genetic differences in the modulation of accumbal glutamate and γ-amino butyric acid levels after cocaine-induced reinstatement. Addict Biol 2013; 18:623-32. [PMID: 22004520 DOI: 10.1111/j.1369-1600.2011.00404.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The Lewis (LEW) and Fischer 344 (F344) inbred rat strains are frequently used to study the role of genetic factors in vulnerability to drug addiction and relapse. Glutamate and γ-amino butyric acid (GABA) transmission are significantly altered after cocaine-induced reinstatement, although whether LEW and F344 rats differ in their accumbal glutamate and GABA responsiveness to cocaine-induced reinstatement remains unknown. To investigate this, we measured by in vivo microdialysis extracellular glutamate and GABA levels in the core division of the nucleus accumbens after extinction of cocaine self-administration and during cocaine-induced reinstatement (7.5mg/kg, i.p.) in these two strains of rats. No strain differences were evident in cocaine self-administration or extinction behavior, although cocaine priming did induce a higher rate of lever pressing in LEW compared with F344 rats. After extinction, F344 rats that self-administered cocaine had less GABA than the saline controls, while the glutamate levels remained constant in both strains. There was more accumbal glutamate after cocaine priming in LEW rats that self-administered cocaine, while GABA levels were unaffected. By contrast, GABA increased transiently in F344 rats that self-administered cocaine, while glutamate levels were unaltered. In F344 saline controls, cocaine priming provoked contrasting effects in glutamate and GABA levels, inducing a delayed increase in glutamate and a delayed decrease in GABA levels. These amino acids were unaffected by cocaine priming in LEW saline rats. Together, these results suggest that genetic differences in cocaine-induced reinstatement reflect different responses of the accumbal GABA and glutamate systems to cocaine priming.
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Affiliation(s)
- Miguel Miguéns
- Departamento de Psicología Básica I, Facultad de Psicología, UNED, Spain.
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Rao PSS, Sari Y. Glutamate transporter 1: target for the treatment of alcohol dependence. Curr Med Chem 2013; 19:5148-56. [PMID: 22680643 DOI: 10.2174/092986712803530511] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2012] [Revised: 05/04/2012] [Accepted: 05/07/2012] [Indexed: 12/19/2022]
Abstract
Emerging evidence indicates that many aspects of alcohol and drug dependence involve changes in glutamate transmission. A number of studies have reported that drugs of abuse, including alcohol and cocaine, alter glutamate transport. Extracellular glutamate is regulated by a number of glutamate transporters in various brain regions. Of these transporters, glutamate transporter (GLT1) is a key player in the removal of most of the extracellular glutamate. Similar to neurodegenerative disease models, in which there is dysfunction of the glutamatergic excitatory system, the role of GLT1 has been tested in drug dependence models that show dysfunction of glutamate transmission. We and others have recently found that ceftriaxone, an FDA-approved drug known to elevate GLT1 expression, attenuates cue-induced cocaine relapse. Moreover, we recently found that alcohol-preferring rats treated with ceftriaxone showed a significant dosedependent reduction in alcohol consumption. We also demonstrated that ceftriaxone-induced upregulation of GLT1 expression was associated with increases in glutamate uptake in Huntington's disease mouse model. Importantly, ceftriaxone is currently in clinical trials for the treatment of amyotrophic lateral sclerosis. This review provides information about the potential therapeutic role of GLT1 for the treatment of alcohol abuse and dependence.
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Affiliation(s)
- P S S Rao
- University of Toledo, College of Pharmacy and Pharmaceutical Sciences, Department of Pharmacology, Health Science Campus, 3000 Arlington Avenue, Toledo, OH 43614, USA
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Sari Y. Potential therapeutic role of glutamate transporter 1 for the treatment of alcohol dependence. ACTA ACUST UNITED AC 2013; 1:6. [PMID: 24409344 DOI: 10.13172/2053-0285-1-1-574] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
INTRODUCTION Evidence has demonstrated that deficits in glutamate transmission impair neurocircuits involved in drug abuse or drug-seeking behaviour and affect many aspects of neuroplasticity associated with alcohol and drug addiction. Alcohol-seeking behaviour is promoted by increased glutamate transmission in key regions of the mesocorticolimbic reward circuit, including the nucleus accumbens and prefrontal cortex. Glutamate transmission or glutamate uptake is regulated by a number of glutamate transporters in the brain regions. Among these glutamate transporters, glutamate transporter 1 (GLT1; its human homolog is the excitatory amino acid transporter 2, EAAT2) regulates the removal of majority of the extracellular glutamate. The role of GLT1 has been tested in alcohol and other drugs of abuse models with dysfunction in glutamate transmission. We recently reported that treatment of alcohol-preferring rats with compounds ceftriaxone and GPI-1046, known to upregulate GLT1 levels, showed reduction in alcohol intake and attenuation of relapse-like ethanol-drinking behaviour. Furthermore, we demonstrated that upregulation of GLT1 was associated with attenuation of cue-induced cocaine relapse. Together, we suggest that GLT1 is considered as a potential therapeutic target for the treatment of drug dependence, including alcohol. The aim of this critical review was to discuss the potential therapeutic role of GLT1 for the treatment of alcohol dependence. CONCLUSION Dysfunction of glutamate transmission has been suggested to impair neurocircuits involved in alcohol dependence, which affect neuroplasticity that is associated with ethanol intake.
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Affiliation(s)
- Y Sari
- University of Toledo, College of Pharmacy and Pharmaceutical Sciences, Department of Pharmacology, Toledo, Ohio, USA
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Ding ZM, Rodd ZA, Engleman EA, Bailey JA, Lahiri DK, McBride WJ. Alcohol drinking and deprivation alter basal extracellular glutamate concentrations and clearance in the mesolimbic system of alcohol-preferring (P) rats. Addict Biol 2013; 18:297-306. [PMID: 23240885 PMCID: PMC3584204 DOI: 10.1111/adb.12018] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The present study determined the effects of voluntary ethanol drinking and deprivation on basal extracellular glutamate concentrations and clearance in the mesolimbic system and tested the hypothesis that chronic ethanol drinking would persistently increase basal glutamate neurotransmission. Three groups of alcohol-preferring (P) rats were used: 'water group (WG),' 'ethanol maintenance group (MG; 24-hour free choice water versus 15% ethanol)' and 'ethanol deprivation group (DG; 2 weeks of deprivation).' Quantitative microdialysis and Western blots were conducted to measure basal extracellular glutamate concentrations, clearance and proteins associated with glutamate clearance. Chronic alcohol drinking produced a 70-100% increase of basal extracellular glutamate concentrations in the posterior ventral tegmental area (4.0 versus 7.0 μM) and nucleus accumbens shell (3.0 versus 6.0 μM). Glutamate clearances were reduced by 30-40% in both regions of MG rats compared with WG rats. In addition, Western blots revealed a 40-45% decrease of excitatory amino transporter 1 (EAAT1) protein, but no significant changes in the levels of EAAT2 or cystine-glutamate antiporter in these regions of MG versus WG rats. The enhanced glutamate concentrations returned to control levels, accompanied by a recovery of glutamate clearance following deprivation. These results indicated that chronic alcohol drinking enhanced extracellular glutamate concentrations in the mesolimbic system, as a result, in part, of reduced clearance, suggesting that enhanced glutamate neurotransmission may contribute to the maintenance of alcohol drinking. However, because the increased glutamate levels returned to normal after deprivation, elevated glutamate neurotransmission may not contribute to the initiation of relapse drinking.
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Affiliation(s)
- Zheng-Ming Ding
- Institute of Psychiatric Research, Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN 46202-4887, USA.
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Gabriele A, Pacchioni AM, See RE. Dopamine and glutamate release in the dorsolateral caudate putamen following withdrawal from cocaine self-administration in rats. Pharmacol Biochem Behav 2012; 103:373-9. [PMID: 23026056 PMCID: PMC3494757 DOI: 10.1016/j.pbb.2012.09.015] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Revised: 09/18/2012] [Accepted: 09/23/2012] [Indexed: 12/01/2022]
Abstract
Evidence suggests that cocaine addiction may involve progressive neuroadaptive changes in the dorsolateral caudate putamen (dlCPu). While cocaine seeking following abstinence from chronic self-administration requires intact dlCPu function, in vivo neurotransmitter release in the dlCPu has not been investigated. The current study measured dlCPu dopamine (DA) and glutamate (GLU) release during drug seeking following limited or extended abstinence, as well as in response to a cocaine priming injection alone. Male, Sprague-Dawley rats self-administered cocaine (0.2mg/50μl infusion, i.v.) for 10days (2h/day). In vivo microdialysis occurred in the self-administration chamber after 1 and 14days of abstinence (Experiment 1). A separate set of animals that completed self-administration as well as drug naïve controls received a cocaine priming injection (20mg/kg) during concurrent microdialysis (Experiment 2). DA release increased during drug seeking in the self-administration context at both 1 and 14days post abstinence. In contrast, GLU release only increased after 1day of abstinence. Furthermore, animals with a cocaine self-administration history showed enhanced DA and GLU release following cocaine challenge as compared to drug naïve controls. These results indicate that chronic cocaine self-administration enhances dlCPu DA and GLU under both drug-paired context and drug-primed conditions.
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Affiliation(s)
- Amanda Gabriele
- Department of Neurosciences, Medical University of South Carolina, Charleston, SC 29425, USA
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Effects of alcohol on the membrane excitability and synaptic transmission of medium spiny neurons in the nucleus accumbens. Alcohol 2012; 46:317-27. [PMID: 22445807 DOI: 10.1016/j.alcohol.2011.12.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2011] [Revised: 12/05/2011] [Accepted: 12/19/2011] [Indexed: 12/29/2022]
Abstract
Chronic and excessive alcohol drinking lead to alcohol dependence and loss of control over alcohol consumption, with serious detrimental health consequences. Chronic alcohol exposure followed by protracted withdrawal causes profound alterations in the brain reward system that leads to marked changes in reinforcement mechanisms and motivational state. These long-lasting neuroadaptations are thought to contribute to the development of cravings and relapse. The nucleus accumbens (NAcc), a central component of the brain reward system, plays a critical role in alcohol-induced neuroadaptive changes underlying alcohol-seeking behaviors. Here we review the findings that chronic alcohol exposure produces long-lasting neuroadaptive changes in various ion channels that govern intrinsic membrane properties and neuronal excitability, as well as excitatory and inhibitory synaptic transmission in the NAcc that underlie alcohol-seeking behavior during protracted withdrawal.
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Zachar G, Wagner Z, Tábi T, Bálint E, Szökő É, Csillag A. Differential Changes of Extracellular Aspartate and Glutamate in the Striatum of Domestic Chicken Evoked by High Potassium or Distress: An In Vivo Microdialysis Study. Neurochem Res 2012; 37:1730-7. [DOI: 10.1007/s11064-012-0783-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2011] [Revised: 04/01/2012] [Accepted: 04/12/2012] [Indexed: 02/03/2023]
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Distinct neurochemical adaptations within the nucleus accumbens produced by a history of self-administered vs non-contingently administered intravenous methamphetamine. Neuropsychopharmacology 2012; 37:707-22. [PMID: 22030712 PMCID: PMC3260984 DOI: 10.1038/npp.2011.248] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Methamphetamine is a highly addictive psychomotor stimulant yet the neurobiological consequences of methamphetamine self-administration remain under-characterized. Thus, we employed microdialysis in rats trained to self-administer intravenous (IV) infusions of methamphetamine (METH-SA) or saline (SAL) and a group of rats receiving non-contingent IV infusions of methamphetamine (METH-NC) at 1 or 21 days withdrawal to determine the dopamine and glutamate responses in the nucleus accumbens (NAC) to a 2 mg/kg methamphetamine intraperitoneal challenge. Furthermore, basal NAC extracellular glutamate content was assessed employing no net-flux procedures in these three groups at both time points. At both 1- and 21-day withdrawal points, methamphetamine elicited a rise in extracellular dopamine in SAL animals and this effect was sensitized in METH-NC rats. However, METH-SA animals showed a much greater sensitized dopamine response to the drug challenge compared with the other groups. Additionally, acute methamphetamine decreased extracellular glutamate in both SAL and METH-NC animals at both time-points. In contrast, METH-SA rats exhibited a modest and delayed rise in glutamate at 1-day withdrawal and this rise was sensitized at 21 days withdrawal. Finally, no net-flux microdialysis revealed elevated basal glutamate and increased extraction fraction at both withdrawal time-points in METH-SA rats. Although METH-NC rats exhibited no change in the glutamate extraction fraction, they exhibited a time-dependent elevation in basal glutamate levels. These data illustrate for the first time that a history of methamphetamine self-administration produces enduring changes in NAC neurotransmission and that non-pharmacological factors have a critical role in the expression of these methamphetamine-induced neurochemical adaptations.
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Higuera-Matas A, Miguéns M, Coria SM, Assis MA, Borcel E, del Olmo N, Ambrosio E. Sex-specific disturbances of the glutamate/GABA balance in the hippocampus of adult rats subjected to adolescent cannabinoid exposure. Neuropharmacology 2012; 62:1975-84. [PMID: 22245681 DOI: 10.1016/j.neuropharm.2011.12.028] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2011] [Revised: 12/22/2011] [Accepted: 12/23/2011] [Indexed: 10/14/2022]
Abstract
Adolescence is a period of active synaptic remodelling and plasticity and as such, a developmental phase of particular vulnerability to the effects of environmental insults. The endogenous cannabinoid system regulates central nervous system development and cannabinoid exposure during adolescence has been linked to several alterations to hippocampal-dependent processes such as cognition and emotion, which rely on intact glutamatergic and GABAergic systems. Here we show that K(+)-induced γ-amino butyric acid (GABA) release increases in the CA1 hippocampal field of Wistar rats of both sexes that were treated chronically with the cannabinoid agonist CP 55,940 (CP55940) during adolescence. GABA(B) receptors levels also increased in cannabinoid-exposed rats. In addition, CP55940-treated females exhibit reduced GABA transporter gene expression (GAT-1), increased GABA(A) receptor expression, as well as decreased K(+)-induced glutamate release and NMDA receptor levels. CP55940 administration did not affect the glial (EAAT2) or neuronal (EAAT3) glutamate transporter gene expression in either males or females, and nor were any changes in the mGlu5 receptor protein levels observed. Taken together, these results show that while the exacerbated GABA release induced by early cannabinoid exposure may be compensated by an increment in GABA(B) receptors, which normally function as inhibitory autoreceptors, adolescent cannabinoid exposure in the females disturbs the normal balance between glutamate and GABA transmission. These observations may provide important insight into the neuronal basis of the well-documented alterations in cognitive and emotional processes induced by adolescent cannabinoid exposure.
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Affiliation(s)
- Alejandro Higuera-Matas
- Department of Psychobiology, School of Psychology, UNED, C/Juan del Rosal no 10, 28040 Madrid, Spain.
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Van den Oever MC, Spijker S, Smit AB. The synaptic pathology of drug addiction. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 970:469-91. [PMID: 22351069 DOI: 10.1007/978-3-7091-0932-8_21] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
A hallmark of drug addiction is the uncontrollable desire to consume drugs at the expense of severe negative consequences. Moreover, addicts that successfully refrain from drug use have a high vulnerability to relapse even after months or years of abstinence. In this chapter, we will discuss the current understanding of drug-induced neuroplasticity within the mesocorticolimbic brain system that contributes to the development of addiction and the persistence of relapse to drug seeking. I particular, we will focus at animal models that can be translated to human addiction. Although dopaminergic transmission is important for the acute effects of drug intake, the long-lived behavioral abnormalities associated with addiction are thought to arise from pathological plasticity in glutamatergic neurotransmission. The nature of changes in excitatory synaptic plasticity depends on several factors, including the type of drug, the brain area, and the time-point studied in the transition of drug exposure to withdrawal and relapse to drug seeking. Identification of drug-induced neuroplasticity is crucial to understand how molecular and cellular adaptations contribute to the end stage of addiction, which from a clinical perspective, is a time-point where pharmacotherapy may be most effectively employed.
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Affiliation(s)
- Michel C Van den Oever
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, VU University, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands
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Neural Changes Developed during the Extinction of Cocaine Self-Administration Behavior. Pharmaceuticals (Basel) 2011; 4:1315-27. [PMID: 26791639 PMCID: PMC4060127 DOI: 10.3390/ph4101315] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2011] [Accepted: 09/20/2011] [Indexed: 02/06/2023] Open
Abstract
The high rate of recidivism in cocaine addiction after prolonged periods of abstinence poses a significant problem for the effective treatment of this condition. Moreover, the neurobiological basis of this relapse phenomenon remains poorly understood. In this review, we will discuss the evidence currently available regarding the neurobiological changes during the extinction of cocaine self-administration. Specifically, we will focus on alterations in the dopaminergic, opioidergic, glutamatergic, cholinergic, serotoninergic and CRF systems described in self-administration experiments and extinction studies after chronic cocaine administration. We will also discuss the differences related to contingent versus non-contingent cocaine administration, which highlights the importance of environmental cues on drug effects and extinction. The findings discussed in this review may aid the development of more effective therapeutic approaches to treat cocaine relapse.
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Chronic cocaine exposure induces putamen glutamate and glutamine metabolite abnormalities in squirrel monkeys. Psychopharmacology (Berl) 2011; 217:367-75. [PMID: 21494788 PMCID: PMC3169716 DOI: 10.1007/s00213-011-2292-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2010] [Accepted: 03/26/2011] [Indexed: 12/17/2022]
Abstract
RATIONALE Chronic cocaine exposure has been associated with progressive brain structural and functional changes. Clarifying mechanisms underlying cocaine's progressive brain effects may help in the development of effective cocaine abuse treatments. OBJECTIVES We used a controlled squirrel monkey model of chronic cocaine exposure (45 mg/kg/week for 9 months) combined with ultra-high magnetic field (9.4 T) proton magnetic resonance spectroscopy to prospectively measure putamen metabolite changes. METHODS Proton metabolites were measured with a STEAM sequence, quantified with LCModel using a simulated basis set, and expressed as metabolite/total creatine (tCr) ratios. RESULTS We found cocaine-induced time-dependent changes in putamen glutamate/tCr and glutamine/tCr metabolite ratios suggestive of altered glutamate compartmentalization, neurotransmission, and metabolism. By contrast, saline-treated monkeys exhibited no metabolite changes over time. The time course of cocaine-induced metabolite abnormalities we detected is consistent with the apparent time course of glutamate abnormalities identified in a cross-sectional study in human cocaine users, as well as with microdialysis findings in rodent models of repeated cocaine exposure. CONCLUSIONS Together, these findings suggests that this squirrel monkey model may be useful for characterizing glutamatergic changes associated with cocaine exposure and for determining efficacies of treatments designed to mitigate cocaine-induced glutamatergic system dysfunction.
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48
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Effects of chronic cocaine administration on spatial learning and hippocampal spine density in two genetically different strains of rats. Neurobiol Learn Mem 2011; 95:491-7. [DOI: 10.1016/j.nlm.2011.02.012] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2010] [Revised: 02/03/2011] [Accepted: 02/22/2011] [Indexed: 12/31/2022]
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Duncan JR, Lawrence AJ. The role of metabotropic glutamate receptors in addiction: evidence from preclinical models. Pharmacol Biochem Behav 2011; 100:811-24. [PMID: 21443897 DOI: 10.1016/j.pbb.2011.03.015] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2010] [Revised: 02/21/2011] [Accepted: 03/16/2011] [Indexed: 11/25/2022]
Abstract
Addiction is a chronic disorder characterised by repeated bouts of drug taking, abstinence and relapse. The addicted state may be in part due to drug-induced neuroadaptations in the mesocorticolimbic and corticostriatal pathways. Recently focus has been on the role of aberrant glutamate transmission and its contribution to the hierarchical control over these systems. This review will expand our current knowledge of the most recent advances that have been made in preclinical animal models that provide evidence that implicate metabotropic glutamate receptors (mGluRs) in contributing to the neuroadaptations pertinent to addiction, as well as the role of Homer proteins in regulating these responses. The recent discovery of receptor mosaics will be discussed which add an additional dimension to the complexity of understanding the mechanism of glutamate mediated behaviours. Finally this review introduces a new area related to glutamatergic responses, namely microRNAs, that may become pivotal in directing our future understanding of how to best target intervention strategies to prevent addictive behaviours.
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Affiliation(s)
- Jhodie R Duncan
- Florey Neuroscience Institutes, University of Melbourne, Parkville, Vic., 3010, Australia.
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50
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Beveridge TJR, Smith HR, Nader MA, Porrino LJ. Group II metabotropic glutamate receptors in the striatum of non-human primates: dysregulation following chronic cocaine self-administration. Neurosci Lett 2011; 496:15-9. [PMID: 21458540 DOI: 10.1016/j.neulet.2011.03.077] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2011] [Revised: 03/22/2011] [Accepted: 03/24/2011] [Indexed: 10/18/2022]
Abstract
A growing body of evidence has demonstrated a role for group II metabotropic glutamate receptors (mGluRs) in the reinforcing effects of cocaine. These receptors are important given their location in limbic-related areas, and their ability to control the release of glutamate and other neurotransmitters. They are also potential targets for novel pharmacotherapies for cocaine addiction. The present study investigated the impact of chronic cocaine self-administration (9.0mg/kg/session for 100 sessions, 900 mg/kg total intake) on the densities of group II mGluRs, as assessed with in vitro receptor autoradiography, in the striatum of adult male rhesus monkeys. Binding of [(3)H]LY341495 to group II mGluRs in control animals was heterogeneous, with a medial to lateral gradient in binding density. Significant elevations in the density of group II mGluRs following chronic cocaine self-administration were measured in the dorsal, central and ventral portions of the caudate nucleus (P<0.05), compared to controls. No differences in receptor density were observed between the groups in either the putamen or nucleus accumbens. These data demonstrate that group II mGluRs in the dorsal striatum are more sensitive to the effects of chronic cocaine exposure than those in the ventral striatum. Cocaine-induced dysregulation of the glutamate system, and its consequent impact on plasticity and synaptic remodeling, will likely be an important consideration in the development of novel pharmacotherapies for cocaine addiction.
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Affiliation(s)
- T J R Beveridge
- Department of Physiology and Pharmacology, Wake Forest University School of Medicine, Medical Center Boulevard, Winston Salem, NC 27157, USA.
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