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Lutfy K, Zaveri NT. The Nociceptin Receptor as an Emerging Molecular Target for Cocaine Addiction. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2015; 137:149-81. [PMID: 26810001 DOI: 10.1016/bs.pmbts.2015.10.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Cocaine addiction is a global public health and socioeconomic issue that requires pharmacological and cognitive therapies. Currently there are no FDA-approved medications to treat cocaine addiction. However, in preclinical studies, interventions ranging from herbal medicine to deep-brain stimulation have shown promise for the therapy of cocaine addiction. Recent developments in molecular biology, pharmacology, and medicinal chemistry have enabled scientists to identify novel molecular targets along the pathways involved in drug addiction. In 1994, a receptor that showed a great deal of homology to the traditional opioid receptors was characterized. However, endogenous and exogenous opioids failed to bind to this receptor, which led scientists to name it opioid receptor-like receptor, now referred to as the nociceptin receptor. The endogenous ligand of NOPr was identified a year later and named orphanin FQ/nociceptin. Nociceptin and NOPr are widely distributed throughout the CNS and are involved in many physiological responses, such as food intake, nociceptive processing, neurotransmitter release, etc. Furthermore, exogenous nociceptin has been shown to regulate the activity of mesolimbic dopaminergic neurons, glutamate, and opioid systems, and the stress circuit. Importantly, exogenous nociceptin has been shown to reduce the rewarding and addictive actions of a number of drugs of abuse, such as psychostimulants, alcohol, and opioids. This paper reviews the existing literature on the role of endogenous nociceptin in the rewarding and addictive actions of cocaine. The effect of exogenous nociceptin on these processes is also reviewed. Furthermore, the effects of novel small-molecule NOPr ligands on these actions of cocaine are discussed. Overall, a review of the literature suggests that NOPr could be an emerging target for cocaine addiction pharmacotherapy.
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Affiliation(s)
- Kabirullah Lutfy
- Department of Pharmaceutical Sciences, College of Pharmacy, Western University of Health Sciences, Pomona, California, USA.
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Hypothalamic Amylin Acts in Concert with Leptin to Regulate Food Intake. Cell Metab 2015; 22:1059-67. [PMID: 26655697 DOI: 10.1016/j.cmet.2015.10.012] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Revised: 08/05/2015] [Accepted: 10/22/2015] [Indexed: 11/21/2022]
Abstract
In this report we evaluated the functions of hypothalamic amylin in vivo and in vitro. Profiling of hypothalamic neurons revealed that islet amyloid polypeptide (Iapp, precursor to amylin) is expressed in neurons in the lateral hypothalamus, arcuate nucleus, medial preoptic area, and elsewhere. Hypothalamic expression of lapp is markedly decreased in ob/ob mice and normalized by exogenous leptin. In slices, amylin and leptin had similar electrophysiologic effects on lateral hypothalamic leptin receptor ObRb-expressing neurons, while the amylin antagonist AC187 inhibited their activity and blunted the effect of leptin. Finally, i.c.v. infusion of AC187 acutely reduced the anorectic effects of leptin. These data show that hypothalamic amylin is transcriptionally regulated by leptin, that it can act directly on ObRb neurons in concert with leptin, and that it regulates feeding. These findings provide a potential mechanism for the increased efficacy of a metreleptin/pramlintide combination therapy for obesity.
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Crowley NA, Kash TL. Kappa opioid receptor signaling in the brain: Circuitry and implications for treatment. Prog Neuropsychopharmacol Biol Psychiatry 2015; 62:51-60. [PMID: 25592680 PMCID: PMC4465498 DOI: 10.1016/j.pnpbp.2015.01.001] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Revised: 12/20/2014] [Accepted: 01/04/2015] [Indexed: 12/15/2022]
Abstract
Kappa opioid receptors (KORs) in the central nervous system have been known to be important regulators of a variety of psychiatry illnesses, including anxiety and addiction, but their precise involvement in these disorders is complex and has yet to be fully elucidated. Here, we briefly review the pharmacology of KORs in the brain, including KOR's involvement in anxiety, depression, and drug addiction. We also review the known neuronal circuitry impacted by KOR signaling, and interactions with corticotrophin-releasing factor (CRF), another key peptide in anxiety-related illnesses, as well as the role of glucocorticoids. We suggest that KORs are a promising therapeutic target for a host of neuropsychiatric conditions.
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Affiliation(s)
- Nicole A. Crowley
- Neurobiology Curriculum, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA,Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Thomas L. Kash
- Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA,Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
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Cohen A, Whitfield TW, Kreifeldt M, Koebel P, Kieffer BL, Contet C, George O, Koob GF. Virus-mediated shRNA knockdown of prodynorphin in the rat nucleus accumbens attenuates depression-like behavior and cocaine locomotor sensitization. PLoS One 2014; 9:e97216. [PMID: 24816773 PMCID: PMC4016270 DOI: 10.1371/journal.pone.0097216] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Accepted: 04/16/2014] [Indexed: 01/10/2023] Open
Abstract
Dynorphins, endogenous opioid peptides that arise from the precursor protein prodynorphin (Pdyn), are hypothesized to be involved in the regulation of mood states and the neuroplasticity associated with addiction. The current study tested the hypothesis that dynorphin in the nucleus accumbens (NAcc) mediates such effects. More specifically, we examined whether knockdown of Pdyn within the NAcc in rats would alter the expression of depressive-like and anxiety-like behavior, as well as cocaine locomotor sensitization. Wistar rats were injected with adeno-associated viral (AAV) vectors encoding either a Pdyn-specific short hairpin RNA (AAV-shPdyn) or a scrambled shRNA (AAV-shScr) as control. Four weeks later, rats were tested for anxiety-like behavior in the elevated plus maze test and depressive-like behavior in the forced swim test (FST). Finally, rats received one daily injection of saline or cocaine (20 mg/kg, i.p.), followed by assessment of locomotion for 4 consecutive days. Following 3 days of abstinence, the rats completed 2 additional daily cocaine/saline locomotor trials. Pdyn knockdown in the NAcc led to a significant reduction in depressive-like behavior in the FST, but had no effect on anxiety-like behavior in the elevated plus maze. Pdyn knockdown did not alter baseline locomotor behavior, the locomotor response to acute cocaine, or the initial sensitization of the locomotor response to cocaine over the first 4 cocaine treatment days. However, following 3 days abstinence the locomotor response to the cocaine challenge returned to their original levels in the AAV-shPdyn rats while remaining heightened in the AAV-shScr rats. These results suggest that dynorphin in a very specific area of the nucleus accumbens contributes to depressive-like states and may be involved in neuroadaptations in the NAcc that contribute to the development of cocaine addiction as a persistent and lasting condition.
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Affiliation(s)
- Ami Cohen
- Committee on the Neurobiology of Addictive Disorders, The Scripps Research Institute, La Jolla, California, United States of America
- * E-mail:
| | - Timothy W. Whitfield
- Committee on the Neurobiology of Addictive Disorders, The Scripps Research Institute, La Jolla, California, United States of America
| | - Max Kreifeldt
- Committee on the Neurobiology of Addictive Disorders, The Scripps Research Institute, La Jolla, California, United States of America
| | - Pascale Koebel
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Translational Medicine and Neurogenetic Programme, UdS Université de Strasbourg, INSERM U964, CNRS UMR7104, Illkirch, France
| | - Brigitte L. Kieffer
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Translational Medicine and Neurogenetic Programme, UdS Université de Strasbourg, INSERM U964, CNRS UMR7104, Illkirch, France
| | - Candice Contet
- Committee on the Neurobiology of Addictive Disorders, The Scripps Research Institute, La Jolla, California, United States of America
| | - Olivier George
- Committee on the Neurobiology of Addictive Disorders, The Scripps Research Institute, La Jolla, California, United States of America
| | - George F. Koob
- Committee on the Neurobiology of Addictive Disorders, The Scripps Research Institute, La Jolla, California, United States of America
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Charbogne P, Kieffer BL, Befort K. 15 years of genetic approaches in vivo for addiction research: Opioid receptor and peptide gene knockout in mouse models of drug abuse. Neuropharmacology 2013; 76 Pt B:204-17. [PMID: 24035914 DOI: 10.1016/j.neuropharm.2013.08.028] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2013] [Revised: 08/19/2013] [Accepted: 08/23/2013] [Indexed: 12/21/2022]
Abstract
The endogenous opioid system is expressed throughout the brain reinforcement circuitry, and plays a major role in reward processing, mood control and the development of addiction. This neuromodulator system is composed of three receptors, mu, delta and kappa, interacting with a family of opioid peptides derived from POMC (β-endorphin), preproenkephalin (pEnk) and preprodynorphin (pDyn) precursors. Knockout mice targeting each gene of the opioid system have been created almost two decades ago. Extending classical pharmacology, these mutant mice represent unique tools to tease apart the specific role of each opioid receptor and peptide in vivo, and a powerful approach to understand how the opioid system modulates behavioral effects of drugs of abuse. The present review summarizes these studies, with a focus on major drugs of abuse including morphine/heroin, cannabinoids, psychostimulants, nicotine or alcohol. Genetic data, altogether, set the mu receptor as the primary target for morphine and heroin. In addition, this receptor is essential to mediate rewarding properties of non-opioid drugs of abuse, with a demonstrated implication of β-endorphin for cocaine and nicotine. Delta receptor activity reduces levels of anxiety and depressive-like behaviors, and facilitates morphine-context association. pEnk is involved in these processes and delta/pEnk signaling likely regulates alcohol intake. The kappa receptor mainly interacts with pDyn peptides to limit drug reward, and mediate dysphoric effects of cannabinoids and nicotine. Kappa/dynorphin activity also increases sensitivity to cocaine reward under stressful conditions. The opioid system remains a prime candidate to develop successful therapies in addicted individuals, and understanding opioid-mediated processes at systems level, through emerging genetic and imaging technologies, represents the next challenging goal and a promising avenue in addiction research. This article is part of a Special Issue entitled 'NIDA 40th Anniversary Issue'.
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Affiliation(s)
- Pauline Charbogne
- IGBMC Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS UMR 7104 - Inserm U964, Illkirch F-67404, France; CNRS, UMR7104, Illkirch F-67404, France; UdS Université de Strasbourg, CNRS UMR 7104 - Inserm U964, Illkirch F-67404, France; Inserm U964, Illkirch F-67404, France
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Kitaichi Y, Hashimoto R, Inoue T, Abekawa T, Kakuta A, Hattori S, Koyama T. Abnormalities in extracellular glycine and glutamate levels in the striatum of sandy mice. Acta Neuropsychiatr 2013; 25:215-20. [PMID: 25287634 DOI: 10.1111/acn.12018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVE Glycine regulates glutamatergic neurotransmission, and several papers have reported the relationship between glycine and schizophrenia. The dysbindin-1 (DTNBP1: dystrobrevin-binding protein 1) gene is related to glutamatergic neurotransmission and has been found to be a strong candidate gene for schizophrenia. In this study, we clarified the relationship between dysbindin, glutamate, and glycine with in vivo microdialysis methods. METHODS We measured extracellular glycine and glutamate levels in the striatum of sandy (sdy) mice using in vivo microdialysis methods. Sdy mice express no dysbindin protein owing to a deletion in the dysbindin-1 gene. In addition, we measured changes in those amino acids after methamphetamine (METH) administration. RESULTS The basal levels of extracellular glycine and glutamate in the striatum of sdy mice were elevated. These extracellular glutamate levels decreased gradually after METH administration and were not subsequently different from those of wild-type mice. CONCLUSIONS These results suggest that dysbindin might modulate glycine and glutamate release in vivo.
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Affiliation(s)
- Yuji Kitaichi
- 1 Department of Psychiatry, Hokkaido University Graduate School of Medicine, Kita-ku, Sapporo, Japan
| | - Ryota Hashimoto
- 2 Molecular Research Center for Children's Mental Development, United Graduate School of Child Development, Osaka University, Osaka, Japan
| | - Takeshi Inoue
- 1 Department of Psychiatry, Hokkaido University Graduate School of Medicine, Kita-ku, Sapporo, Japan
| | - Tomohiro Abekawa
- 1 Department of Psychiatry, Hokkaido University Graduate School of Medicine, Kita-ku, Sapporo, Japan
| | - Aya Kakuta
- 1 Department of Psychiatry, Hokkaido University Graduate School of Medicine, Kita-ku, Sapporo, Japan
| | - Satoko Hattori
- 4 Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, Japan
| | - Tsukasa Koyama
- 1 Department of Psychiatry, Hokkaido University Graduate School of Medicine, Kita-ku, Sapporo, Japan
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Yoo JH, Kitchen I, Bailey A. The endogenous opioid system in cocaine addiction: what lessons have opioid peptide and receptor knockout mice taught us? Br J Pharmacol 2012; 166:1993-2014. [PMID: 22428846 DOI: 10.1111/j.1476-5381.2012.01952.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Cocaine addiction has become a major concern in the UK as Britain tops the European 'league table' for cocaine abuse. Despite its devastating health and socio-economic consequences, no effective pharmacotherapy for treating cocaine addiction is available. Identifying neurochemical changes induced by repeated drug exposure is critical not only for understanding the transition from recreational drug use towards compulsive drug abuse but also for the development of novel targets for the treatment of the disease and especially for relapse prevention. This article focuses on the effects of chronic cocaine exposure and withdrawal on each of the endogenous opioid peptides and receptors in rodent models. In addition, we review the studies that utilized opioid peptide or receptor knockout mice in order to identify and/or clarify the role of different components of the opioid system in cocaine-addictive behaviours and in cocaine-induced alterations of brain neurochemistry. The review of these studies indicates a region-specific activation of the µ-opioid receptor system following chronic cocaine exposure, which may contribute towards the rewarding effect of the drug and possibly towards cocaine craving during withdrawal followed by relapse. Cocaine also causes a region-specific activation of the κ-opioid receptor/dynorphin system, which may antagonize the rewarding effect of the drug, and at the same time, contribute to the stress-inducing properties of the drug and the triggering of relapse. These conclusions have important implications for the development of effective pharmacotherapy for the treatment of cocaine addiction and the prevention of relapse.
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Affiliation(s)
- Ji Hoon Yoo
- Division of Biochemistry, Faculty of Health & Medical Sciences, University of Surrey, Guildford, Surrey, UK
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Tejeda HA, Natividad LA, Orfila JE, Torres OV, O’Dell LE. Dysregulation of kappa-opioid receptor systems by chronic nicotine modulate the nicotine withdrawal syndrome in an age-dependent manner. Psychopharmacology (Berl) 2012; 224:289-301. [PMID: 22659976 PMCID: PMC3482308 DOI: 10.1007/s00213-012-2752-7] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2011] [Accepted: 05/16/2012] [Indexed: 11/25/2022]
Abstract
RATIONALE Mechanisms that mediate age differences during nicotine withdrawal are unclear. OBJECTIVE This study compared kappa-opioid receptor (KOR) activation in naïve and nicotine-treated adolescent and adult rats using behavioral and neurochemical approaches to study withdrawal. METHODS The behavioral models used to assess withdrawal included conditioned place and elevated plus maze procedures. Deficits in dopamine transmission in the nucleus accumbens (NAcc) were examined using microdialysis procedures. Lastly, the effects of KOR stimulation and blockade on physical signs produced upon removal of nicotine were examined in adults. RESULTS Nicotine-treated adults displayed a robust aversion to an environment paired with a KOR agonist versus naïve adults. Neither of the adolescent groups displayed a place aversion. KOR activation produced an increase in anxiety-like behavior that was highest in nicotine-treated adults versus all other groups. KOR activation produced a decrease in NAcc dopamine that was largest in nicotine-treated adults versus all other groups. Lastly, KOR activation facilitated physical signs of withdrawal upon removal of nicotine and KOR blockade reduced this effect. CONCLUSION Chronic nicotine enhanced the affective, anxiogenic, and neurochemical effects produced by KOR activation in adult rats. Our data suggest that chronic nicotine elicits an increase in KOR function, and this may contribute to nicotine withdrawal since KOR activation facilitated and KOR blockade prevented withdrawal signs upon removal of nicotine. Given that chronic nicotine facilitated the neurochemical effects of KOR agonists in adults but not in adolescents, it is suggested that KOR regulation of mesolimbic dopamine may contribute to age differences in nicotine withdrawal.
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MESH Headings
- 3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer/administration & dosage
- 3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer/pharmacology
- Aging
- Animals
- Behavior, Animal/drug effects
- Dopamine/metabolism
- Dose-Response Relationship, Drug
- Male
- Naltrexone/administration & dosage
- Naltrexone/analogs & derivatives
- Naltrexone/pharmacology
- Nicotine/pharmacology
- Nucleus Accumbens/metabolism
- Rats
- Rats, Wistar
- Receptors, Opioid, kappa/agonists
- Receptors, Opioid, kappa/antagonists & inhibitors
- Substance Withdrawal Syndrome/drug therapy
- Tobacco Use Disorder/drug therapy
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Affiliation(s)
- Hugo A. Tejeda
- Department of Psychology, The University of Texas at El Paso, 500 West University Avenue, El Paso, Texas, 79968
- Integrative Neuroscience Section, Integrative Neuroscience Branch, National Institute on Drug Abuse Intramural Research Program, 333 Cassell Dr., Baltimore, Maryland, 21224
- Program in Neuroscience, University of Maryland, Baltimore School of Medicine, 20 Penn Street, Baltimore, Maryland, 21201
| | - Luis A. Natividad
- Department of Psychology, The University of Texas at El Paso, 500 West University Avenue, El Paso, Texas, 79968
| | - James E. Orfila
- Department of Psychology, The University of Texas at El Paso, 500 West University Avenue, El Paso, Texas, 79968
| | - Oscar V. Torres
- Department of Psychology, The University of Texas at El Paso, 500 West University Avenue, El Paso, Texas, 79968
| | - Laura E. O’Dell
- Department of Psychology, The University of Texas at El Paso, 500 West University Avenue, El Paso, Texas, 79968
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Femenía T, Manzanares J. Increased ethanol intake in prodynorphin knockout mice is associated to changes in opioid receptor function and dopamine transmission. Addict Biol 2012; 17:322-37. [PMID: 21966993 DOI: 10.1111/j.1369-1600.2011.00378.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The purpose of this study was to examine the role of the prodynorphin gene in alcohol sensitivity, preference and vulnerability to alcohol consumption. Handling-induced convulsion (HIC) associated to alcohol, alcohol-induced loss of righting reflex (LORR), hypothermic effects in response to acute ethanol challenge, blood ethanol levels (BELs), conditioned place preference, voluntary ethanol consumption and preference, tyrosine hydroxylase (TH), dopamine transporter (DAT) and proenkephalin (PENK) gene expression, and µ-, δ- and κ-opioid agonist-stimulated [S(35) ]- guanosine 5'-triphosphate-binding autoradiography were studied in prodynorphin knockout (PDYN KO) and wild-type (WT) mice. There were no differences in HIC, LORR or the decrease in body temperature in response to acute ethanol challenge between PDYN KO and WT mice. PDYN KO mice presented higher BEL, higher ethanol-conditioned place preference and more ethanol consumption and preference in a two-bottle choice paradigm than WT mice. These findings were associated with lower TH and higher DAT gene expression in the ventral tegmental area and substantia nigra, and with lower PENK gene expression in the caudate-putamen (CPu), accumbens core (AcbC) and accumbens shell (AcbSh) in PDYN KO. The functional activity of the µ-opioid receptor was lower in the CPu, AcbC, AcbSh and cingulate cortex (Cg) of PDYN KO mice. In contrast, δ- and κ-opioid receptor-binding autoradiographies were increased in the CPu and Cg (δ), and in the CPu, AcbC and Cg (κ) of PDYN KO. These results suggest that deletion of the PDYN gene increased vulnerability for ethanol consumption by altering, at least in part, PENK, TH and DAT gene expression, and µ-, δ- and κ-opioid receptor functional activity in brain areas closely related to ethanol reinforcement.
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Affiliation(s)
- Teresa Femenía
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, San Juan de Alicante, Spain
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Nguyen K, Tseng A, Marquez P, Hamid A, Lutfy K. The role of endogenous dynorphin in ethanol-induced state-dependent CPP. Behav Brain Res 2011; 227:58-63. [PMID: 22074899 DOI: 10.1016/j.bbr.2011.10.035] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2011] [Revised: 10/18/2011] [Accepted: 10/23/2011] [Indexed: 11/29/2022]
Abstract
The aim of this study was to determine the role of the endogenous dynorphin/kappa opioid receptor (DYN/KOP) system in ethanol-induced state-dependent conditioned place preference (CPP). To this end, mice lacking the pro-DYN gene and their wild-type littermates/controls were tested for baseline place preference on day 1, received 15-min morning and afternoon conditionings with saline or ethanol (2g/kg) each day for three consecutive days and were then tested for CPP under a drug-free state on day 5 and following a saline or ethanol (1 or 2g/kg) challenge on day 8. Given that compensatory developmental changes may occur in knockout mice, the effect of nor-binaltorphimine (nor-BNI), a KOP antagonist, on state-dependent CPP induced by ethanol was also studied in wild-type mice. On day 1, mice were tested for baseline place preference and, 4h later, treated with saline or nor-BNI (10mg/kg). On days 2-4, mice received 15-min morning and afternoon conditionings and were tested for CPP under a drug-free state on day 5 and following an ethanol (1g/kg) challenge on day 8. A comparable CPP was observed in mice lacking the pro-DYN gene and their wild-type littermates/controls as well as in wild-type mice treated with nor-BNI and their saline-treated controls. However, these mice compared to their respective controls exhibited a greater CPP response following an ethanol (1g/kg) challenge, suggesting that the endogenous DYN/KOP system may negatively regulate ethanol-induced state-dependent CPP.
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Affiliation(s)
- Khanh Nguyen
- Department of Pharmaceutical Sciences, College of Pharmacy, Western University of Health Sciences, Pomona, CA 91766, United States
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11
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Han W, Takamatsu Y, Yamamoto H, Kasai S, Endo S, Shirao T, Kojima N, Ikeda K. Inhibitory role of inducible cAMP early repressor (ICER) in methamphetamine-induced locomotor sensitization. PLoS One 2011; 6:e21637. [PMID: 21738744 PMCID: PMC3125264 DOI: 10.1371/journal.pone.0021637] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2011] [Accepted: 06/04/2011] [Indexed: 12/02/2022] Open
Abstract
Background The inducible cyclic adenosine monophosphate (cAMP) early repressor (ICER) is highly expressed in the central nervous system and functions as a repressor of cAMP response element-binding protein (CREB) transcription. The present study sought to clarify the role of ICER in the effects of methamphetamine (METH). Methods and Findings We tested METH-induced locomotor sensitization in wildtype mice, ICER knockout mice, and ICER I-overexpressing mice. Both ICER wildtype mice and knockout mice displayed increased locomotor activity after continuous injections of METH. However, ICER knockout mice displayed a tendency toward higher locomotor activity compared with wildtype mice, although no significant difference was observed between the two genotypes. Moreover, compared with wildtype mice, ICER I-overexpressing mice displayed a significant decrease in METH-induced locomotor sensitization. Furthermore, Western blot analysis and quantitative real-time reverse transcription polymerase chain reaction demonstrated that ICER overexpression abolished the METH-induced increase in CREB expression and repressed cocaine- and amphetamine-regulated transcript (CART) and prodynorphin (Pdyn) expression in mice. The decreased CART and Pdyn mRNA expression levels in vivo may underlie the inhibitory role of ICER in METH-induced locomotor sensitization. Conclusions Our data suggest that ICER plays an inhibitory role in METH-induced locomotor sensitization.
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Affiliation(s)
- Wenhua Han
- Research Project for Addictive Substances, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Yukio Takamatsu
- Research Project for Addictive Substances, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Hideko Yamamoto
- Research Project for Addictive Substances, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Shinya Kasai
- Research Project for Addictive Substances, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Shogo Endo
- Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan
| | - Tomoaki Shirao
- Department of Neurobiology and Behavior, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Nobuhiko Kojima
- Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan
- Department of Neurobiology and Behavior, Gunma University Graduate School of Medicine, Maebashi, Japan
- Laboratory for Neurobiology of Emotion, RIKEN Brain Science Institute, Wako, Japan
- * E-mail:
| | - Kazutaka Ikeda
- Research Project for Addictive Substances, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
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Yoo JH, Bailey A, Ansonoff M, Pintar JE, Matifas A, Kieffer BL, Kitchen I. Lack of genotype effect on D1, D2 receptors and dopamine transporter binding in triple MOP-, DOP-, and KOP-opioid receptor knockout mice of three different genetic backgrounds. Synapse 2010; 64:520-7. [PMID: 20196137 DOI: 10.1002/syn.20757] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
We investigated D1, D2 receptors and dopamine transporter (DAT) binding levels in mice lacking all three opioid receptors and wild-type (WT) mice on three different genetic backgrounds. Quantitative autoradiography was used to determine the level of radioligand binding to the D1 and D2 receptors and DAT labeled with [(3)H]SCH23390, [(3)H]raclopride, and [(3)H]mazindol, respectively in triple-opioid receptor knockout (KO) and WT maintained on C57BL/6 (B6) and 129/SvEvTac (129) as well as C57BL/6 x 129/SvPas (B6 x 129) strains. No significant genotype effect was observed in D1, D2 receptors and DAT binding in any regions analyzed in any of the strains studied, suggesting that a lack of all three opioid receptors does not influence D1, D2 receptors and DAT expression, irrespective of their genetic strain background. However, strain differences were observed in D1 binding between the three strains of mice studied. Lower levels of D1 binding were observed in the substantia nigra of B6 x 129 WT mice compared with the 129 WT mice and in the olfactory tubercle of B6 x 129 WT compared with B6 WT and 129 WT mice. Lower levels of D1 binding were observed in the caudate putamen of B6 x 129 KO mice compared with 129 KO mice. In contrast, no significant strain differences were observed in D2 and DAT binding between the three strains of mice in any regions analyzed. Overall, these results indicate a lack of modulation of the dopaminergic system by the deletion of all three opioid receptors regardless of different background strains.
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Affiliation(s)
- Ji-Hoon Yoo
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey, GU2 7XH, United Kingdom
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Tejeda HA, Chefer VI, Zapata A, Shippenberg TS. The effects of kappa-opioid receptor ligands on prepulse inhibition and CRF-induced prepulse inhibition deficits in the rat. Psychopharmacology (Berl) 2010; 210:231-40. [PMID: 20232058 PMCID: PMC2946822 DOI: 10.1007/s00213-010-1799-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2009] [Accepted: 02/10/2010] [Indexed: 11/30/2022]
Abstract
RATIONALE Kappa-opioid receptor (KOR) agonists produce dysphoria and psychotomimesis in humans. KORs are enriched in the prefrontal cortex and other brain regions that regulate mood and cognitive function. Dysregulation of the dynorphin/KOR system has been implicated in the pathogenesis of schizophrenia, depression, and bipolar disorder. Prepulse inhibition of the acoustic startle reflex (PPI), a sensorimotor gating process, is disrupted in many psychiatric disorders. OBJECTIVES The present study determined whether KOR ligands alter PPI in rats. RESULTS Utilizing a range of doses of the synthetic KOR agonists (+/-) U50,488, (-) U50,488, and U69,593 and the naturally occurring KOR agonist, Salvinorin A, we demonstrate that KOR activation does not alter PPI or startle reactivity in rats. Similarly, selective KOR blockade using the long-acting antagonist nor-binaltorphimine (nor-BNI) was without effect. In contrast to KOR ligands, MK-801 and quinpirole produced deficits in PPI. Stress and corticotropin-releasing factor (CRF) decrease PPI levels. The dynorphin/KOR system has been suggested to be a key mediator of various behavioral effects produced by stress and CRF. We therefore examined the contribution of KORs to CRF-induced alterations in PPI. Intracerebroventricular infusion of CRF decreased PPI. Administration of nor-BNI failed to affect the CRF-evoked disruption in PPI. CONCLUSIONS Together, these results provide no evidence of a link between the dynorphin/KOR system and deficits in sensory gating processes. Additional studies, however, examining whether dysregulation of this opioid system contributes to cognitive deficits and other behavioral abnormalities associated with psychiatric disorders are warranted.
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MESH Headings
- 3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer/pharmacology
- Animals
- Benzeneacetamides/pharmacology
- Corticotropin-Releasing Hormone/pharmacology
- Diterpenes, Clerodane/pharmacology
- Dose-Response Relationship, Drug
- Ligands
- Male
- Naltrexone/analogs & derivatives
- Naltrexone/pharmacology
- Neural Inhibition
- Pyrrolidines/pharmacology
- Rats
- Rats, Sprague-Dawley
- Receptors, Opioid, kappa/agonists
- Receptors, Opioid, kappa/antagonists & inhibitors
- Reflex, Startle/drug effects
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Affiliation(s)
- Hugo A. Tejeda
- Integrative Neuroscience Section, Integrative Neuroscience Branch, National Institute on Drug Abuse, National Institutes of Health, NIDA/IRP 333 Cassell Dr., Baltimore, MD 21224, USA
- Program in Neuroscience, University of Maryland, Baltimore, 20 Penn St., Baltimore, MD 21201, USA
| | - Vladimir I. Chefer
- Integrative Neuroscience Section, Integrative Neuroscience Branch, National Institute on Drug Abuse, National Institutes of Health, NIDA/IRP 333 Cassell Dr., Baltimore, MD 21224, USA
| | - Agustin Zapata
- Integrative Neuroscience Section, Integrative Neuroscience Branch, National Institute on Drug Abuse, National Institutes of Health, NIDA/IRP 333 Cassell Dr., Baltimore, MD 21224, USA
| | - Toni S. Shippenberg
- Integrative Neuroscience Section, Integrative Neuroscience Branch, National Institute on Drug Abuse, National Institutes of Health, NIDA/IRP 333 Cassell Dr., Baltimore, MD 21224, USA
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14
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Briand LA, Blendy JA. Molecular and genetic substrates linking stress and addiction. Brain Res 2009; 1314:219-34. [PMID: 19900417 DOI: 10.1016/j.brainres.2009.11.002] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2009] [Revised: 11/02/2009] [Accepted: 11/03/2009] [Indexed: 12/19/2022]
Abstract
Drug addiction is one of the top three health concerns in the United States in terms of economic and health care costs. Despite this, there are very few effective treatment options available. Therefore, understanding the causes and molecular mechanisms underlying the transition from casual drug use to compulsive drug addiction could aid in the development of treatment options. Studies in humans and animal models indicate that stress can lead to both vulnerability to develop addiction, and increased drug taking and relapse in addicted individuals. Exposure to stress or drugs of abuse results in long-term adaptations in the brain that are likely to involve persistent alterations in gene expression or activation of transcription factors, such as the cAMP Response Element Binding (CREB) protein. The signaling pathways controlled by CREB have been strongly implicated in drug addiction and stress. Many potential CREB target genes have been identified based on the presence of a CRE element in promoter DNA sequences. These include, but are not limited to CRF, BDNF, and dynorphin. These genes have been associated with initiation or reinstatement of drug reward and are altered in one direction or the other following stress. While many reviews have examined the interactions between stress and addiction, the goal of this review was to focus on specific molecules that play key roles in both stress and addiction and are therefore posed to mediate the interaction between the two. Focus on these molecules could provide us with new targets for pharmacological treatments for addiction.
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Affiliation(s)
- Lisa A Briand
- Department of Pharmacology, The University of Pennsylvania School of Medicine, TRL, 125 South 31(st) Street, USA
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15
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Nguyen XV, Liu M, Kim HC, Bing G. Effects of prodynorphin deletion on striatal dopamine in mice during normal aging and in response to MPTP. Exp Neurol 2009; 219:228-38. [PMID: 19500577 DOI: 10.1016/j.expneurol.2009.05.028] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2009] [Revised: 05/21/2009] [Accepted: 05/23/2009] [Indexed: 11/17/2022]
Abstract
Dynorphins, endogenous neuropeptides found in striatonigral neurons, have been observed to exhibit dopamine-inhibitory actions and under some circumstances possess intrinsic neurotoxic activity. To test the hypothesis that dynorphin suppression mitigates effects of aging on the striatal dopaminergic system, HPLC quantitation of dopamine and related amines was performed on striatal homogenates of wild-type (WT) mice and mice lacking the prodynorphin (Pdyn) gene at varying ages. Pdyn knockout (KO) mice at 10 and 20 months show significant elevations in striatal dopamine compared to 3-month mice. Differences in tyrosine hydroxylase (TH) immunoreactivity could not account for these findings, but phosphorylation of TH at Ser40, but not Ser31, was enhanced in aged Pdyn KO mice. Systemic administration of MPTP produced significant dopamine depletion in an age-dependent manner, but Pdyn deletion conferred no protection against MPTP-induced dopamine loss, arguing against a mechanism by which Pdyn deletion enhances dopaminergic neuron survival. The above findings demonstrate an age-dependent inhibitory effect of dynorphins on striatal dopamine synthesis via modulation of TH activity.
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Affiliation(s)
- Xuan V Nguyen
- Department of Anatomy and Neurobiology, University of Kentucky College of Medicine, 800 Rose Street, Lexington, KY 40536, USA
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16
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Léna I, Bradshaw S, Pintar J, Kitchen I. Adaptive changes in the expression of central opioid receptors in mice lacking the dopamine D2 receptor gene. Neuroscience 2008; 153:773-88. [DOI: 10.1016/j.neuroscience.2008.02.070] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2007] [Revised: 02/22/2008] [Accepted: 02/23/2008] [Indexed: 10/22/2022]
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17
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Gehrke BJ, Chefer VI, Shippenberg TS. Effects of acute and repeated administration of salvinorin A on dopamine function in the rat dorsal striatum. Psychopharmacology (Berl) 2008; 197:509-17. [PMID: 18246329 PMCID: PMC3700373 DOI: 10.1007/s00213-007-1067-6] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2007] [Accepted: 12/21/2007] [Indexed: 12/15/2022]
Abstract
RATIONALE Acute systemic administration of salvinorin A, a naturally occurring kappa-opioid receptor (KOPr) agonist, decreases locomotion and striatal dopamine (DA) overflow. OBJECTIVES Conventional and quantitative microdialysis techniques were used to determine whether salvinorin A infusion into the dorsal striatum (DSTR) decreases DA overflow by altering DA uptake or release. The influence of repeated salvinorin A administration on basal DA dynamics and cocaine-evoked alterations in DA overflow and locomotion was also assessed. MATERIALS AND METHODS Salvinorin A was administered via the dialysis probe (0; 20-200 nM) or via intraperitoneal (i.p.) injection (1.0 or 3.2 mg/kg per day x 5 days). The effects of a challenge dose of cocaine were examined 48 h after repeated salvinorin treatment. RESULTS Retrodialysis of salvinorin A produced a dose-related, KOPr antagonist reversible, decrease in DA levels. Extracellular DA levels were decreased whereas DA extraction fraction, which provides an estimate of DA uptake, was unaltered. In contrast to its acute administration, repeated salvinorin A administration did not modify dialysate DA levels. Similarly, neither basal extracellular DA levels nor DA uptake was altered. Unlike synthetic KOPr agonists, prior repeated administration of salvinorin A did not attenuate the locomotor activating effects of an acute cocaine (20 mg/kg, i.p.) challenge. However, cocaine-evoked DA overflow was enhanced. CONCLUSIONS These data demonstrate that acute, but not repeated, salvinorin A administration decreases mesostriatal neurotransmission and that activation of DSTR KOPr is sufficient for this effect. Differences in the interaction of salvinorin and synthetic KOPr agonists with cocaine suggest that the pharmacology of these agents may differ.
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Affiliation(s)
- Brenda J Gehrke
- Integrative Neuroscience Section, NIH/NIDA Intramural Research Program, Baltimore, MD 21224, USA.
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18
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Logrip ML, Janak PH, Ron D. Dynorphin is a downstream effector of striatal BDNF regulation of ethanol intake. FASEB J 2008; 22:2393-404. [PMID: 18310464 DOI: 10.1096/fj.07-099135] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We recently identified brain-derived neurotrophic factor (BDNF) in the dorsal striatum to be a major component of a homeostatic pathway controlling ethanol consumption. We hypothesized that ethanol-mediated activation of the BDNF signaling cascade is required for the ethanol-related function of the neurotrophic factor. Here, we demonstrate that exposure of striatal neurons to ethanol results in the activation of the BDNF receptor TrkB, leading to the activation of the mitogen-activated protein kinase (MAP kinase) signaling pathway and the subsequent increase in the expression of preprodynorphin (Pdyn) via BDNF. Finally, we show that activation of the dynorphin receptor, the kappa opioid receptor (KOR), is required for the BDNF-mediated decrease in ethanol intake, illustrating a function of dynorphin in BDNF's homeostatic control of ethanol consumption. Taken together, these results demonstrate that BDNF regulates ethanol intake by initiation of MAP kinase signaling and the ensuing production of downstream gene products, including Pdyn.
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19
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Abstract
This paper is the 29th consecutive installment of the annual review of research concerning the endogenous opioid system, now spanning 30 years of research. It summarizes papers published during 2006 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (Section 2), and the roles of these opioid peptides and receptors in pain and analgesia (Section 3); stress and social status (Section 4); tolerance and dependence (Section 5); learning and memory (Section 6); eating and drinking (Section 7); alcohol and drugs of abuse (Section 8); sexual activity and hormones, pregnancy, development and endocrinology (Section 9); mental illness and mood (Section 10); seizures and neurological disorders (Section 11); electrical-related activity and neurophysiology (Section 12); general activity and locomotion (Section 13); gastrointestinal, renal and hepatic functions (Section 14); cardiovascular responses (Section 15); respiration and thermoregulation (Section 16); and immunological responses (Section 17).
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Affiliation(s)
- Richard J Bodnar
- Department of Psychology and Neuropsychology Doctoral Sub-Program, Queens College, City University of New York, CUNY, 65-30 Kissena Blvd., Flushing, NY 11367, United States.
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20
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Barbier E, Zapata A, Oh E, Liu Q, Zhu F, Undie A, Shippenberg T, Wang JB. Supersensitivity to amphetamine in protein kinase-C interacting protein/HINT1 knockout mice. Neuropsychopharmacology 2007; 32:1774-82. [PMID: 17203012 DOI: 10.1038/sj.npp.1301301] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Protein kinase C interacting protein/histidine triad nucleotide binding protein 1 (PKCI/HINT1) is a member of the histidine triad protein family. Although this protein is widely expressed in the mammalian brain including mesocorticolimbic and mesostriatal regions, its physiological function in CNS remains unknown. Recent microarray studies reported decreased mRNA expression of PKCI/HINT1 in the frontal cortex of individuals with schizophrenia, suggesting the possible involvement of this protein in the pathophysiology of the disease. In view of the documented link between dopamine (DA) transmission and schizophrenia, the present study used behavioral and neurochemical approaches to examine the influence of constitutive PKCI/HINT1 deletion upon: (i) basal and amphetamine (AMPH)-evoked locomotor activity; (ii) DA dynamics in the dorsal striatum, and (iii) postsynaptic DA receptor function. PKCI/HINT1(-/-) (KO) mice displayed lower spontaneous locomotion relative to wild-type (WT) controls. Acute AMPH administration significantly increased locomotor activity in WT mice; nonetheless, the effect was enhanced in KO mice. Quantitative microdialysis studies revealed no alteration in basal DA dynamics in the striatum or nucleus accumbens of KO mice. The ability of acute AMPH to increase DA levels was unaltered indicating that function in presynaptic DA neurotransmission in these regions do not underlie the behavioral phenotype of KO mice. In contrast to WT mice, systemic administration of the direct-acting DA receptor agonist apomorphine (10 mg/kg) significantly increased locomotor activity in KO mice suggesting that postsynaptic DA function is altered in these animals. These results demonstrate an important role of PKCI/HINT1 in modulating the behavioral response to AMPH. Furthermore, they indicate that the absence of this protein may be associated with dysregulation of postsynaptic DA transmission.
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Affiliation(s)
- Elisabeth Barbier
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, MD 21201, USA
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21
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Bailey A, Yoo JH, Racz I, Zimmer A, Kitchen I. Preprodynorphin mediates locomotion and D2 dopamine and mu-opioid receptor changes induced by chronic 'binge' cocaine administration. J Neurochem 2007; 102:1817-1830. [PMID: 17532787 DOI: 10.1111/j.1471-4159.2007.04661.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Evidence suggests that the kappa-opioid receptor (KOP-r) system plays an important role in cocaine addiction. Indeed, cocaine induces endogenous KOP activity, which is a mechanism that opposes alterations in behaviour and brain function resulting from repeated cocaine use. In this study, we have examined the influence of deletion of preprodynorphin (ppDYN) on cocaine-induced behavioural effects and on hypothalamic-pituitary-adrenal axis activity. Furthermore, we have measured mu-opioid receptor (MOP-r) agonist-stimulated [(35)S]GTPgammaS, dopamine D(1), D(2) receptor and dopamine transporter (DAT) binding. Male wild-type (WT) and ppDYN knockout (KO) mice were injected with saline or cocaine (45 mg/kg/day) in a 'binge' administration paradigm for 14 days. Chronic cocaine produced an enhancement of locomotor sensitisation in KO. No genotype effect was found on stereotypy behaviour. Cocaine-enhanced MOP-r activation in WT but not in KO. There was an overall decrease in D(2) receptor binding in cocaine-treated KO but not in WT mice. No changes were observed in D(1) and DAT binding. Cocaine increased plasma corticosterone levels in WT but not in KO. The data confirms that the endogenous KOP system inhibits dopamine neurotransmission and that ppDYN may mediate the enhancement of MOP-r activity and the activation of the hypothalamic-pituitary-adrenal axis after chronic cocaine treatment.
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MESH Headings
- Analgesics, Opioid/metabolism
- Analgesics, Opioid/pharmacology
- Animals
- Binding, Competitive/drug effects
- Binding, Competitive/physiology
- Cocaine/adverse effects
- Cocaine-Related Disorders/genetics
- Cocaine-Related Disorders/metabolism
- Cocaine-Related Disorders/physiopathology
- Corticosterone/metabolism
- Dopamine Plasma Membrane Transport Proteins/drug effects
- Dopamine Plasma Membrane Transport Proteins/metabolism
- Dopamine Uptake Inhibitors/adverse effects
- Drug Administration Schedule
- Dynorphins/genetics
- Dynorphins/metabolism
- Guanosine 5'-O-(3-Thiotriphosphate)/metabolism
- Hypothalamo-Hypophyseal System/drug effects
- Hypothalamo-Hypophyseal System/metabolism
- Hypothalamo-Hypophyseal System/physiopathology
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Motor Activity/drug effects
- Motor Activity/physiology
- Pituitary-Adrenal System/drug effects
- Pituitary-Adrenal System/physiology
- Protein Precursors/genetics
- Protein Precursors/metabolism
- Receptors, Dopamine D1/drug effects
- Receptors, Dopamine D1/metabolism
- Receptors, Dopamine D2/drug effects
- Receptors, Dopamine D2/metabolism
- Receptors, Opioid, kappa/drug effects
- Receptors, Opioid, kappa/metabolism
- Receptors, Opioid, mu/drug effects
- Receptors, Opioid, mu/metabolism
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Affiliation(s)
- A Bailey
- School of Biomedical and Molecular Sciences, University of Surrey, Guildford, UKDepartment of Molecular Psychiatry, Life & Brain Center, University of Bonn, Bonn, Germany
| | - J H Yoo
- School of Biomedical and Molecular Sciences, University of Surrey, Guildford, UKDepartment of Molecular Psychiatry, Life & Brain Center, University of Bonn, Bonn, Germany
| | - I Racz
- School of Biomedical and Molecular Sciences, University of Surrey, Guildford, UKDepartment of Molecular Psychiatry, Life & Brain Center, University of Bonn, Bonn, Germany
| | - A Zimmer
- School of Biomedical and Molecular Sciences, University of Surrey, Guildford, UKDepartment of Molecular Psychiatry, Life & Brain Center, University of Bonn, Bonn, Germany
| | - I Kitchen
- School of Biomedical and Molecular Sciences, University of Surrey, Guildford, UKDepartment of Molecular Psychiatry, Life & Brain Center, University of Bonn, Bonn, Germany
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22
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Qi CT, Zou H, Zhang CH, Xie QL, Jin ML, Yu L. Effect of GNTI, a kappa opioid receptor antagonist, on MK-801-induced hyperlocomotion and stereotypy in mice. Acta Pharmacol Sin 2006; 27:1401-8. [PMID: 17049114 DOI: 10.1111/j.1745-7254.2006.00448.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
AIM To examine the effect of GNTI [5'-guanidinyl-17-(cyclopropylmethyl)-6,7- dehydro-4,5alpha-epoxy-3,14-dihydroxy-6,7-2',3'-indolomorphinan], a selective antagonist for the kappa opioid receptor, in the MK-801 (dizocilpine maleate)-induced behavioral model of psychosis in schizophrenia as a way to explore the involvement of the kappa opioid receptor in modulating psychotic symptoms of schizophrenia. METHODS Two doses of MK-801 (0.3 mg/kg and 0.6 mg/kg) were administered by systemic injection in mice to induce psychosis-like behavior as a rodent schizophrenia model, preceded by an injection of different doses of GNTI. Both locomotion and stereotypy were measured as the behavioral endpoints for quantitative analysis. RESULTS GNTI inhibited MK-801-induced hyperlocomotion and stereotypy. In particular, GNTI showed differential modulation of stereotypy induced by 0.3 mg/kg vs 0.6 mg/kg MK-801. CONCLUSION Antagonism of kappa opioid receptors attenuates MK-801-induced behavior, suggesting a potential involvement of the kappa opioid receptor in psychosis-like symptoms of schizophrenia. GNTI appears to be a useful pharmacological tool to explore the kappa opioid receptor function in vivo.
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Affiliation(s)
- Chun-ting Qi
- Research Center for Biotechnology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200233, China
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23
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Blednov YA, Walker D, Martinez M, Harris RA. Reduced alcohol consumption in mice lacking preprodynorphin. Alcohol 2006; 40:73-86. [PMID: 17307643 PMCID: PMC1850187 DOI: 10.1016/j.alcohol.2006.12.002] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2006] [Revised: 11/30/2006] [Accepted: 12/22/2006] [Indexed: 11/29/2022]
Abstract
Many studies suggest a role for endogenous opioid peptides and their receptors in regulation of ethanol intake. It is commonly accepted that the kappa-opioid receptors and their endogenous ligands, dynorphins, produce a dysphoric state and therefore may be responsible for avoidance of alcohol. We used mutant mice lacking preprodynorphin in a variety of behavioral tests of alcohol actions. Null mutant female, but not male, mice showed significantly lower preference for alcohol and consumed lower amounts of alcohol in a two-bottle choice test as compared with wild-type littermates. In the same test, knockout mice of both sexes showed a strong reduction of preference for saccharin compared to control mice. In contrast, under conditions of limited (4 h) access (light phase of the light/dark cycle), null mutant mice did not show any differences in consumption of saccharin, but they showed significantly reduced intake of sucrose. To determine the possible cause for reduction of ethanol preference and intake, we studied other ethanol-related behaviors in mice lacking the preprodynorphin gene. There were no differences between null mutant and wild-type mice in ethanol-induced loss of righting reflex, acute ethanol withdrawal, ethanol-induced conditioned place preference, or conditioned taste aversion to ethanol. These results indicate that deletion of preprodynorphin leads to substantial reduction of alcohol intake in female mice, and suggest that this is caused by decreased orosensory reward of alcohol (sweet taste and/or palatability).
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Affiliation(s)
- Yuri A Blednov
- University of Texas, Waggoner Center for Alcohol and Addiction Research, 1 University Station A4800, Austin, TX 78712-0159, USA.
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