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Zhang YZ, Wang SY, Guo XC, Liu XH, Wang XF, Wang MM, Qiu TT, Han FT, Zhang Y, Wang CL. Novel endomorphin analogues CEMR-1 and CEMR-2 produce potent and long-lasting antinociception with a favourable side effect profile at the spinal level. Br J Pharmacol 2024; 181:1268-1289. [PMID: 37990825 DOI: 10.1111/bph.16287] [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: 12/22/2022] [Revised: 10/09/2023] [Accepted: 11/08/2023] [Indexed: 11/23/2023] Open
Abstract
BACKGROUND AND PURPOSE Endomorphins have shown great promise as pharmaceutics for the treatment of pain. We have previously confirmed that novel endomorphin analogues CEMR-1 and CEMR-2 behaved as potent μ agonists and displayed potent antinociceptive activities at the supraspinal and peripheral levels. The present study was undertaken to evaluate the antinociceptive properties of CEMR-1 and CEMR-2 following intrathecal (i.t.) administration. Furthermore, their antinociceptive tolerance and opioid-like side effects were also determined. EXPERIMENTAL APPROACH The spinal antinociceptive effects of CEMR-1 and CEMR-2 were determined in a series of pain models, including acute radiant heat paw withdrawal test, spared nerve injury-induced neuropathic pain, complete Freund's adjuvant-induced inflammatory pain, visceral pain and formalin pain. Antinociceptive tolerance was evaluated in radiant heat paw withdrawal test. KEY RESULTS Spinal administration of CEMR-1 and CEMR-2 produced potent and prolonged antinociceptive effects in acute pain. CEMR-1 and CEMR-2 may produce their antinociception through distinct μ receptor subtypes. These two analogues also exhibited significant analgesic activities in neuropathic, inflammatory, visceral and formalin pain at the spinal level. It is noteworthy that CEMR-1 showed non-tolerance-forming analgesic properties, while CEMR-2 exhibited substantially reduced antinociceptive tolerance. Furthermore, both analogues displayed no or reduced side effects on conditioned place preference response, physical dependence, locomotor activity and gastrointestinal transit. CONCLUSIONS AND IMPLICATIONS The present investigation demonstrated that CEMR-1 and CEMR-2 displayed potent and long-lasting antinociception with a favourable side effect profile at the spinal level. Therefore, CEMR-1 and CEMR-2 might serve as promising analgesic compounds with minimal opioid-like side effects.
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Affiliation(s)
- Yu-Zhe Zhang
- School of Life Science and Technology, Harbin Institute of Technology, Harbin, China
| | - Si-Yu Wang
- School of Life Science and Technology, Harbin Institute of Technology, Harbin, China
| | - Xue-Ci Guo
- School of Life Science and Technology, Harbin Institute of Technology, Harbin, China
| | - Xiao-Han Liu
- School of Life Science and Technology, Harbin Institute of Technology, Harbin, China
| | | | - Meng-Meng Wang
- School of Life Science and Technology, Harbin Institute of Technology, Harbin, China
| | - Ting-Ting Qiu
- School of Life Science and Technology, Harbin Institute of Technology, Harbin, China
| | - Feng-Tong Han
- School of Life Science and Technology, Harbin Institute of Technology, Harbin, China
| | - Yao Zhang
- School of Life Science and Technology, Harbin Institute of Technology, Harbin, China
| | - Chang-Lin Wang
- School of Life Science and Technology, Harbin Institute of Technology, Harbin, China
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, Guangxi Normal University, Guilin, China
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Zhang YZ, Wang MM, Wang SY, Wang XF, Yang WJ, Zhao YN, Han FT, Zhang Y, Gu N, Wang CL. Novel Cyclic Endomorphin Analogues with Multiple Modifications and Oligoarginine Vector Exhibit Potent Antinociception with Reduced Opioid-like Side Effects. J Med Chem 2021; 64:16801-16819. [PMID: 34781680 DOI: 10.1021/acs.jmedchem.1c01631] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Endomorphins (EMs) are potent pharmaceuticals for the treatment of pain. Herein, we investigated several novel EM analogues with multiple modifications and oligoarginine conjugation. Our results showed that analogues 1-6 behaved as potent μ-opioid agonists and enhanced stability and lipophilicity. Analogues 5 and 6 administered centrally and peripherally induced significant and prolonged antinociceptive effects in acute pain. Both analogues also produced long-acting antiallodynic effects against neuropathic and inflammatory pain. Furthermore, they showed a reduced acute antinociceptive tolerance. Analogue 6 decreased the extent of chronic antinociceptive tolerance, and analogue 5 exhibited no tolerance at the supraspinal level. Particularly, they displayed nontolerance-forming antinociception at the peripheral level. In addition, analogues 5 and 6 exhibited reduced or no opioid-like side effects on gastrointestinal transit, conditioned place preference (CPP), and motor impairment. The present investigation established that multiple modifications and oligoarginine-vector conjugation of EMs would be helpful in developing novel analgesics with fewer side effects.
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Affiliation(s)
- Yu-Zhe Zhang
- School of Life Science and Technology, Harbin Institute of Technology, 92 West Dazhi Street, Harbin 150001, China
| | - Meng-Meng Wang
- School of Life Science and Technology, Harbin Institute of Technology, 92 West Dazhi Street, Harbin 150001, China
| | - Si-Yu Wang
- School of Life Science and Technology, Harbin Institute of Technology, 92 West Dazhi Street, Harbin 150001, China
| | - Xiao-Fang Wang
- Jiangxi University of Chinese Medicine, Nanchang 330004, China
| | - Wen-Jiao Yang
- School of Life Science and Technology, Harbin Institute of Technology, 92 West Dazhi Street, Harbin 150001, China
| | - Ya-Nan Zhao
- School of Life Science and Technology, Harbin Institute of Technology, 92 West Dazhi Street, Harbin 150001, China
| | - Feng-Tong Han
- School of Life Science and Technology, Harbin Institute of Technology, 92 West Dazhi Street, Harbin 150001, China
| | - Yao Zhang
- School of Life Science and Technology, Harbin Institute of Technology, 92 West Dazhi Street, Harbin 150001, China
| | - Ning Gu
- School of Life Science and Technology, Harbin Institute of Technology, 92 West Dazhi Street, Harbin 150001, China
| | - Chang-Lin Wang
- School of Life Science and Technology, Harbin Institute of Technology, 92 West Dazhi Street, Harbin 150001, China.,Stake Key Laboratory of Natural and Biomimetic Drugs, Peking University, Beijing 100191, China
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Exposure to morphine-associated cues increases mu opioid receptor mRNA expression in the nucleus accumbens of Wistar Kyoto rats. Behav Brain Res 2016; 313:208-213. [DOI: 10.1016/j.bbr.2016.07.017] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Revised: 06/21/2016] [Accepted: 07/11/2016] [Indexed: 11/22/2022]
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Wang ZL, Li N, Wang P, Tang HH, Han ZL, Song JJ, Li XH, Yu HP, Zhang T, Zhang R, Xu B, Zhang MN, Fang Q, Wang R. Pharmacological characterization of EN-9, a novel chimeric peptide of endomorphin-2 and neuropeptide FF that produces potent antinociceptive activity and limited tolerance. Neuropharmacology 2016; 108:364-72. [DOI: 10.1016/j.neuropharm.2016.03.017] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Revised: 03/08/2016] [Accepted: 03/08/2016] [Indexed: 01/19/2023]
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Sanchez-Catalan MJ, Kaufling J, Georges F, Veinante P, Barrot M. The antero-posterior heterogeneity of the ventral tegmental area. Neuroscience 2014; 282:198-216. [PMID: 25241061 DOI: 10.1016/j.neuroscience.2014.09.025] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Revised: 09/09/2014] [Accepted: 09/10/2014] [Indexed: 11/16/2022]
Abstract
The ventral tegmental area (VTA) is a brain region processing salient sensory and emotional information, controlling motivated behaviors, natural or drug-related reward, reward-related learning, mood, and participating in their associated psychopathologies. Mostly studied for its dopamine neurons, the VTA also includes functionally important GABA and glutamate cell populations. Behavioral evidence supports the presence of functional differences between the anterior VTA (aVTA) and the posterior VTA (pVTA), which is the topic of this review. This antero-posterior heterogeneity concerns locomotor activity, conditioned place preference and intracranial self-administration, and can be seen in response to ethanol, acetaldehyde, salsolinol, opioids including morphine, cholinergic agonists including nicotine, cocaine, cannabinoids and after local manipulation of GABA and serotonin receptors. It has also been observed after viral-mediated manipulation of GluR1, phospholipase Cγ (PLCγ) and cAMP response element binding protein (CREB) expression, with impact on reward and aversion-related responses, on anxiety and depression-related behaviors and on pain sensitivity. In this review, the substrates potentially underlying these aVTA/pVTA differences are discussed, including the VTA sub-nuclei and the heterogeneity in connectivity, cell types and molecular characteristics. We also review the role of the tail of the VTA (tVTA), or rostromedial tegmental nucleus (RMTg), which may also participate to the observed antero-posterior heterogeneity of the VTA. This region, partly located within the pVTA, is an inhibitory control center for dopamine activity. It controls VTA and substantia nigra dopamine cells, thus exerting a major influence on basal ganglia functions. This review highlights the need for a more comprehensive analysis of VTA heterogeneity.
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Affiliation(s)
- M J Sanchez-Catalan
- Institut des Neurosciences Cellulaires et Intégratives, Centre National de la Recherche Scientifique, Strasbourg, France; Université de Strasbourg, Strasbourg, France
| | - J Kaufling
- Centre National de la Recherche Scientifique, Interdisciplinary Institute for Neuroscience, UMR 5297, Bordeaux, France; Université de Bordeaux, Interdisciplinary Institute for Neuroscience, UMR 5297, Bordeaux, France
| | - F Georges
- Centre National de la Recherche Scientifique, Interdisciplinary Institute for Neuroscience, UMR 5297, Bordeaux, France; Université de Bordeaux, Interdisciplinary Institute for Neuroscience, UMR 5297, Bordeaux, France
| | - P Veinante
- Institut des Neurosciences Cellulaires et Intégratives, Centre National de la Recherche Scientifique, Strasbourg, France; Université de Strasbourg, Strasbourg, France
| | - M Barrot
- Institut des Neurosciences Cellulaires et Intégratives, Centre National de la Recherche Scientifique, Strasbourg, France; Université de Strasbourg, Strasbourg, France.
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Paredes R. Opioids and sexual reward. Pharmacol Biochem Behav 2014; 121:124-31. [DOI: 10.1016/j.pbb.2013.11.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Revised: 10/16/2013] [Accepted: 11/07/2013] [Indexed: 10/26/2022]
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7
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Han ZL, Wang ZL, Tang HZ, Li N, Fang Q, Li XH, Yang XL, Zhang XY, Wang R. Neuropeptide FF attenuates the acquisition and the expression of conditioned place aversion to endomorphin-2 in mice. Behav Brain Res 2013; 248:51-6. [DOI: 10.1016/j.bbr.2013.03.046] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Revised: 03/25/2013] [Accepted: 03/28/2013] [Indexed: 12/28/2022]
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Infusion of endomorphin-1 (EM-1) in the MPOA and the Me modulate sexual and socio-sexual behavior in the male rat. Brain Res 2013; 1517:36-43. [DOI: 10.1016/j.brainres.2013.04.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Revised: 03/06/2013] [Accepted: 04/02/2013] [Indexed: 11/23/2022]
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Jhou TC, Xu SP, Lee MR, Gallen CL, Ikemoto S. Mapping of reinforcing and analgesic effects of the mu opioid agonist endomorphin-1 in the ventral midbrain of the rat. Psychopharmacology (Berl) 2012; 224:303-12. [PMID: 22669129 PMCID: PMC3482303 DOI: 10.1007/s00213-012-2753-6] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Accepted: 05/16/2012] [Indexed: 12/30/2022]
Abstract
INTRODUCTION Agonists at the mu opioid receptor (MOR) are widely recognized for their effects on reward and pain. Although prior studies have attributed some of these effects to MORs on GABA neurons in the ventral tegmental area (VTA), recent studies have identified a region of particularly strong MOR immunostaining residing caudal to the VTA, in a region denoted the rostromedial tegmental nucleus (RMTg). METHODS Hence, we examined whether rats would self-administer small doses (50-250 pmol) of the selective MOR agonist endomorphin-1 (EM1) into the RMTg and adjacent sites. EM1 was chosen due to its short half-life, thus limiting drug spread, and due to its presence endogenously in brain neurons, including some afferents to the RMTg. RESULTS The highest rates of EM1 self-administration occurred within 0.5 mm of the RMTg center, in a region roughly 0.8-1.6 mm caudal to the majority of VTA DA neurons. In contrast, self-administration rates were much lower in the adjacent VTA, interpeduncular nucleus, central linear nucleus, or median raphe nucleus. Furthermore, EM1 infusions into the RMTg, but not surrounding regions, produced conditioned place preference, while EM1 infusions into the RMTg but not anterior VTA markedly reduced formalin-induced pain behaviors. EM1 effects were mimicked by infusions of the GABA agonist muscimol into the same region, consistent with EM1 having inhibitory actions on its target neurons. CONCLUSION These results implicate a novel brain region in modulating MOR influences on both appetitive and aversive behavior.
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Affiliation(s)
- Thomas C. Jhou
- Behavioral Neuroscience Branch, National Institute on Drug Abuse, National Institutes of Health, Department of Health and Human Services, Baltimore, MD, USA,Department of Neurosciences, Medical University of South Carolina, 173 Ashley Avenue, Charleston, SC 29425, USA
| | - Sheng-Ping Xu
- Behavioral Neuroscience Branch, National Institute on Drug Abuse, National Institutes of Health, Department of Health and Human Services, Baltimore, MD, USA
| | - Mary R. Lee
- Neuroimaging Research Branch, National Institute on Drug Abuse, National Institutes of Health, Department of Health and Human Services, Baltimore, MD, USA
| | - Courtney L. Gallen
- Neuroimaging Research Branch, National Institute on Drug Abuse, National Institutes of Health, Department of Health and Human Services, Baltimore, MD, USA
| | - Satoshi Ikemoto
- Behavioral Neuroscience Branch, National Institute on Drug Abuse, National Institutes of Health, Department of Health and Human Services, Baltimore, MD, USA
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Nocjar C, Zhang J, Feng P, Panksepp J. The social defeat animal model of depression shows diminished levels of orexin in mesocortical regions of the dopamine system, and of dynorphin and orexin in the hypothalamus. Neuroscience 2012; 218:138-53. [DOI: 10.1016/j.neuroscience.2012.05.033] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2012] [Revised: 05/11/2012] [Accepted: 05/11/2012] [Indexed: 01/13/2023]
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Lack of a rewarding effect and a locomotor-enhancing effect of the selective μ-opioid receptor agonist amidino-TAPA. Psychopharmacology (Berl) 2010; 212:215-25. [PMID: 20683583 DOI: 10.1007/s00213-010-1946-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2010] [Accepted: 06/29/2010] [Indexed: 10/19/2022]
Abstract
RATIONALE AND OBJECTIVES Psychological dependence is one of the worst side effects of morphine. It limits the clinical availability of morphine and non-patient morphine users suffer from addiction. An analgesic, which is more potent than morphine but without the liability of psychological dependence, has long been sought in the clinic. We have recently developed a new μ-opioid receptor agonist, N(α)-amidino-Tyr-D-Arg-Phe-β-Ala (amidino-TAPA), as a potent analgesic with an antinociceptive profile that is distinct from morphine, including the release of endogenous κ-opioid peptides. The activation of κ-opioid receptors has been suggested to suppress the development of psychological dependence by μ-opioid receptor agonists. In the present study, the psychological dependence liability and the related locomotor-enhancing effect of amidino-TAPA were evaluated. RESULTS Amidino-TAPA injected subcutaneously produced an extremely potent and longer lasting antinociception than morphine in ddY mice, prodynorphin-knockout mice, and wild-type C57BL/6J mice. Unlike subcutaneously injected morphine, which had potent locomotor-enhancing and rewarding effects at antinociceptive doses in ddY mice, amidino-TAPA injected subcutaneously did not induce significant locomotor-enhancing and rewarding effects at antinociceptive or even higher doses in ddY mice. In wild-type C57BL/6J mice, amidino-TAPA showed the same pharmacological profile (potent antinociception, lack of locomotor-enhancing and rewarding effects) as in ddY mice. However, amidino-TAPA produced potent locomotor-enhancing and rewarding effects at antinociceptive doses in prodynorphin-knockout mice. CONCLUSIONS The present results suggest that amidino-TAPA is a potent analgesic without the liability of psychological dependence because it releases endogenous κ-opioid peptides.
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Yang CH, Yoon SS, Hansen DM, Wilcox JD, Blumell BR, Park JJ, Steffensen SC. Acupuncture inhibits GABA neuron activity in the ventral tegmental area and reduces ethanol self-administration. Alcohol Clin Exp Res 2010; 34:2137-46. [PMID: 20860620 DOI: 10.1111/j.1530-0277.2010.01310.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Withdrawal from chronic ethanol enhances ventral tegmental area (VTA) GABA neuron excitability and reduces mesolimbic dopamine (DA) neurotransmission, which is suppressed by acupuncture at Shenmen (HT7) points (Zhao et al., 2006). The aim of this study was to evaluate the effects of HT7 acupuncture on VTA GABA neuron excitability, ethanol inhibition of VTA GABA neuron firing rate, and ethanol self-administration. A role for opioid receptors (ORs) in ethanol and acupuncture effects is also explored. METHODS Using electrophysiological methods in mature rats, we evaluated the effects of HT7 stimulation and opioid antagonists on VTA GABA neuron firing rate. Using behavioral paradigms in rats, we evaluated the effects of HT7 stimulation and opioid antagonists on ethanol self-administration using a modification of the sucrose-fading procedure. RESULTS HT7 stimulation produced a biphasic modulation of VTA GABA neuron firing rate characterized by transient enhancement followed by inhibition and subsequent recovery in 5 minutes. HT7 inhibition of VTA GABA neuron firing rate was blocked by systemic administration of the nonselective μ-opioid receptor antagonist naloxone. HT7 stimulation significantly reduced ethanol suppression of VTA GABA neuron firing rate, which was also blocked by naloxone. HT7 acupuncture reduced ethanol self-administration without affecting sucrose consumption. Systemic administration of the δ-opioid receptor (DOR) antagonist naltrindole blocked ethanol suppression of VTA GABA neuron firing rate and significantly reduced ethanol self-administration without affecting sucrose consumption. CONCLUSIONS These findings suggest that DOR-mediated opioid modulation of VTA GABA neurons may mediate acupuncture's role in modulating mesolimbic DA release and suppressing the reinforcing effects of ethanol.
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Le Merrer J, Becker JAJ, Befort K, Kieffer BL. Reward processing by the opioid system in the brain. Physiol Rev 2009; 89:1379-412. [PMID: 19789384 DOI: 10.1152/physrev.00005.2009] [Citation(s) in RCA: 647] [Impact Index Per Article: 43.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The opioid system consists of three receptors, mu, delta, and kappa, which are activated by endogenous opioid peptides processed from three protein precursors, proopiomelanocortin, proenkephalin, and prodynorphin. Opioid receptors are recruited in response to natural rewarding stimuli and drugs of abuse, and both endogenous opioids and their receptors are modified as addiction develops. Mechanisms whereby aberrant activation and modifications of the opioid system contribute to drug craving and relapse remain to be clarified. This review summarizes our present knowledge on brain sites where the endogenous opioid system controls hedonic responses and is modified in response to drugs of abuse in the rodent brain. We review 1) the latest data on the anatomy of the opioid system, 2) the consequences of local intracerebral pharmacological manipulation of the opioid system on reinforced behaviors, 3) the consequences of gene knockout on reinforced behaviors and drug dependence, and 4) the consequences of chronic exposure to drugs of abuse on expression levels of opioid system genes. Future studies will establish key molecular actors of the system and neural sites where opioid peptides and receptors contribute to the onset of addictive disorders. Combined with data from human and nonhuman primate (not reviewed here), research in this extremely active field has implications both for our understanding of the biology of addiction and for therapeutic interventions to treat the disorder.
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Affiliation(s)
- Julie Le Merrer
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Département Neurobiologie et Génétique, Illkirch, France
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Parra-Gámez L, García-Hidalgo AA, Salazar-Juárez A, Antón B, Paredes RG. Endomorphin-1, effects on male sexual behavior. Physiol Behav 2009; 97:98-101. [DOI: 10.1016/j.physbeh.2009.02.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2008] [Revised: 01/30/2009] [Accepted: 02/04/2009] [Indexed: 02/01/2023]
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Delta-opioid receptor expression in the ventral tegmental area protects against elevated alcohol consumption. J Neurosci 2009; 28:12672-81. [PMID: 19036960 DOI: 10.1523/jneurosci.4569-08.2008] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Alcoholism is a complex and debilitating syndrome affecting approximately 140 million people worldwide. However, not everyone who consumes ethanol develops abuse, raising the possibility that some individuals have a protective mechanism that inhibits elevated alcohol consumption. We tested the hypothesis that the delta-opioid receptor (DOR) plays such a protective role. Here we show that DOR activity in the ventral tegmental area (VTA) robustly decreases ethanol consumption in rats and that these effects depend on baseline ethanol consumption. Intra-VTA microinjection of the DOR agonist DPDPE decreases drinking, particularly in low-drinking animals. Furthermore, VTA microinjection of the DOR selective antagonist TIPP-Psi increases drinking in low, but not high, drinkers and this increase is blocked by comicroinjection of the GABA(A) antagonist bicuculline. Using electrophysiological techniques we found that in VTA brain slices from drinking rats DPDPE presynaptically inhibits GABA(A) receptor mediated IPSCs in low drinkers, but not in high drinkers or naive animals, most likely through activation of DORs on GABA terminals. This DOR-mediated inhibition of IPSCs also correlates inversely with behavioral correlates of anxiety measured in the elevated plus maze. In contrast, presynaptic inhibition of VTA GABA(A) IPSCs by the mu-opioid receptor agonist DAMGO is significantly reduced in both high- and low-drinking rats (<30%) compared with age-matched nondrinking controls (>70%). Together, our findings demonstrate the protective nature of VTA DORs and identify an important new target for therapeutic intervention for alcoholism.
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Mitchell JM, Bergren LJ, Chen KS, Rowbotham MC, Fields HL. Naltrexone aversion and treatment efficacy are greatest in humans and rats that actively consume high levels of alcohol. Neurobiol Dis 2009; 33:72-80. [DOI: 10.1016/j.nbd.2008.09.018] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2008] [Revised: 09/10/2008] [Accepted: 09/12/2008] [Indexed: 11/26/2022] Open
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Botros M, Johansson T, Zhou Q, Lindeberg G, Tömböly C, Tóth G, Le Grevès P, Nyberg F, Hallberg M. Endomorphins interact with the substance P (SP) aminoterminal SP(1-7) binding in the ventral tegmental area of the rat brain. Peptides 2008; 29:1820-4. [PMID: 18597894 DOI: 10.1016/j.peptides.2008.05.014] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2008] [Revised: 05/15/2008] [Accepted: 05/17/2008] [Indexed: 10/22/2022]
Abstract
We have recently identified a specific binding site for the tachykinin peptide substance P (SP) fragment SP(1-7) in the rat spinal cord. This site appeared very specific for SP(1-7) as the binding affinity of this compound highly exceeded those of other SP fragments. We also observed that endomorphin-2 (EM-2) exhibited high potency in displacing SP(1-7) from this site. In the present work using a [(3)H]-labeled derivative of the heptapeptide we have identified and characterized [(3)H]-SP(1-7) binding in the rat ventral tegmental area (VTA). Similarly to the [(3)H]-SP(1-7) binding in the spinal cord the affinity of unlabeled SP(1-7) to the specific site in VTA was significantly higher than those of other SP fragments. Further, the tachykinin receptor NK-1, NK-2 and NK-3 ligands showed no or negligible binding to the identified site. However, the mu-opioid peptide (MOP) receptor agonists DAMGO, EM-1 and EM-2 did, and significant difference was observed in the binding affinity between the two endomorphins. As recorded from displacement curves the affinity of EM-2 for the SP(1-7) site was 4-5 times weaker than that for SP(1-7) but about 5 times higher than that of EM-1. The opioid receptor antagonists naloxone and naloxonazine showed weak or negligible binding. It was concluded that the specific site identified for SP(1-7) binding in the rat VTA is distinct from the MOP receptor although it exhibits high affinity for EM-2.
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Affiliation(s)
- Milad Botros
- Department of Pharmaceutical Biosciences, Uppsala University, SE-751 24 Uppsala, Sweden
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Sakurada S, Sawai T, Mizoguchi H, Watanabe H, Watanabe C, Yonezawa A, Morimoto M, Sato T, Komatsu T, Sakurada T. Possible involvement of dynorphin A release via mu1-opioid receptor on supraspinal antinociception of endomorphin-2. Peptides 2008; 29:1554-60. [PMID: 18571771 DOI: 10.1016/j.peptides.2008.04.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2008] [Revised: 04/17/2008] [Accepted: 04/18/2008] [Indexed: 11/26/2022]
Abstract
It has been demonstrated that the antinociception induced by i.t. or i.c.v. administration of endomorphins is mediated through mu-opioid receptors. Moreover, though endomorphins do not have appreciable affinity for kappa-opioid receptors, pretreatment with the kappa-opioid receptor antagonist nor-binaltorphimine markedly blocks the antinociception induced by i.c.v.- or i.t.-injected endomorphin-2, but not endomorphin-1. These evidences propose the hypothesis that endomorphin-2 may initially stimulate the mu-opioid receptors, which subsequently induces the release of dynorphins acting on kappa-opioid receptors to produce antinociception. The present study was performed to determine whether the release of dynorphins by i.c.v.-administered endomorphin-2 is mediated through mu-opioid receptors for producing antinociception. Intracerebroventricular pretreatment with an antiserum against dynorphin A, but not dynorphin B or alpha-neo-endorphin, and s.c. pretreatment with kappa-opioid receptor antagonist nor-binaltorphimine dose-dependently attenuated the antinociception induced by i.c.v.-administered endomorphin-2, but not endomorphin-1 and DAMGO. The attenuation of endomorphin-2-induced antinociception by pretreatment with antiserum against dynorphin A or nor-binaltorphimine was dose-dependently eliminated by additional s.c. pretreatment with a selective mu-opioid receptor antagonist beta-funaltrexamine or a selective mu1-opioid receptor antagonist naloxonazine at ultra low doses, which are inactive against micro-opioid receptor agonists in antinociception, suggesting that endomorphin-2 stimulates distinct subclass of micro1-opioid receptor that induces the release of dynorphin A acting on kappa-opioid receptors in the brain. It concludes that the antinociception induced by supraspinally administered endomorphin-2 is in part mediated through the release of endogenous kappa-opioid peptide dynorphin A, which is caused by the stimulation of distinct subclass of micro1-opioid receptor.
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Affiliation(s)
- Shinobu Sakurada
- Department of Physiology and Anatomy, Tohoku Pharmaceutical University, 4-4-1 Komatsushima, Sendai 981-8558, Japan.
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19
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Terashvili M, Wu HE, Schwasinger ET, Hung KC, Hong JS, Tseng LF. (+)-Morphine attenuates the (-)-morphine-produced conditioned place preference and the mu-opioid receptor-mediated dopamine increase in the posterior nucleus accumbens of the rat. Eur J Pharmacol 2008; 587:147-54. [PMID: 18448094 PMCID: PMC2566855 DOI: 10.1016/j.ejphar.2008.03.020] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2007] [Revised: 01/08/2008] [Accepted: 03/10/2008] [Indexed: 11/18/2022]
Abstract
An unbiased conditioned place preference paradigm and the microdialysis technique was used to evaluate the effect of (+)-morphine pretreatment on the conditioned place preference produced by (-)-morphine and the increased release of the dopamine produced by mu-opioid ligand endomorphin-1, respectively, in the posterior nucleus accumbens shell of the male CD rat. (-)-Morphine (2.5-10 microg) microinjected into the posterior nucleus accumbens shell dose-dependently produced the conditioned place preference. Pretreatment with (+)-morphine (0.1-10 pg) given into the posterior accumbens shell for 45 min dose-dependently attenuated the conditioned place preference produced by (-)-morphine (5 microg) given into the same posterior accumbens shell. However, higher doses of (+)-morphine (0.1 and 1 ng) were less effective in attenuating the (-)-morphine-produced conditioned place preference. Thus, like given systemically, (+)-morphine given into the posterior nucleus accumbens shell also induces a U-shaped dose-response curve for attenuating the (-)-morphine-produced conditioned place preference. Microinjection of mu-opioid agonist endomorphin-1 (1-10 microg) given into the ventral tegmental area dose-dependently increased the release of the extracellular dopamine in the posterior nucleus accumbens shell in the urethane-anesthetized rats. The increased dopamine caused by endomorphin-1 (10 microg) was completed blocked by the (+)-morphine (10 pg) pretreatment given into ventral tegmental area. It is concluded that (+)-morphine attenuates the (-)-morphine-produced conditioned place preference and the mu-opioid receptor-mediated increase of extracellular dopamine in the posterior nucleus accumbens shell of the rat.
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Affiliation(s)
- Maia Terashvili
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI 53226
| | - Hsiang-En Wu
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI 53226
| | - Emma T. Schwasinger
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI 53226
| | - Kuei-Chun Hung
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI 53226
| | - Jau-Shyong Hong
- Neuropharmacology Section, Laboratory of Pharmacology and Chemistry, National Institute of Environmental Health Sciences, National Institute of Health, Research Triangle Park, NC 27709
| | - Leon F. Tseng
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI 53226
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20
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Terashvili M, Tseng LF, Wu HE, Narayanan J, Hart LM, Falck JR, Pratt PF, Harder DR. Antinociception produced by 14,15-epoxyeicosatrienoic acid is mediated by the activation of beta-endorphin and met-enkephalin in the rat ventrolateral periaqueductal gray. J Pharmacol Exp Ther 2008; 326:614-22. [PMID: 18492947 DOI: 10.1124/jpet.108.136739] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Cytochrome P450 genes catalyze formation of epoxyeicosatrienoic acids (EETs) from arachidonic acid. The effects of 5,6-EET, 8,9-EET, 11,12-EET, and 14,15-EET microinjected into the ventrolateral periaqueductal gray (vlPAG) on the thermally produced tail-flick response were studied in male Sprague-Dawley rats. 14,15-EET microinjected into vlPAG (3-156 pmol) dose-dependently inhibited the tail-flick response (ED50 = 32.5 pmol). In contrast, 5,6-EET, 8,9-EET, and 11,12-EET at a dose of 156 pmol were not active when injected into the vlPAG. 14,15-EET failed to displace the radiobinding of [3H][D-Ala2,NHPe4, Gly-ol5]enkephalin (mu-opioid receptor ligand) or [3H]naltrindole (delta-opioid receptor ligand) in crude membrane fractions of rat brain. Tail-flick inhibition produced by 14,15-EET from vlPAG was blocked by intra-vlPAG pretreatment with antiserum against beta-endorphin or Met-enkephalin or the mu-opioid receptor antagonist D-Phe-Cys-Tyr-D-Trp-Orn-Thr-Pen-Thr-NH2 (CTOP) or the delta-opioid receptor antagonist naltrindole but not with dynorphin A[1-17] antiserum or the kappa-opioid receptor antagonist nor-binaltorphimine. In addition, tail-flick inhibition produced by 14,15-EET treatment was blocked by intrathecal pretreatment with Met-enkephalin antiserum, naltrindole, or CTOP but not with beta-endorphin antiserum. It is concluded that 1) 14,15-EET itself does not have any affinity for mu- or delta-opioid receptors and 2) 14,15-EET activates beta-endorphin and Met-enkephalin, which subsequently act on mu- and delta-opioid receptors to produce antinociception.
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Affiliation(s)
- Maia Terashvili
- Department of Physiology, Cardiovascular Research Center, Medical College of Wisconsin, Milwaukee, WI 53226, USA
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21
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Tzschentke TM. Measuring reward with the conditioned place preference (CPP) paradigm: update of the last decade. Addict Biol 2007; 12:227-462. [PMID: 17678505 DOI: 10.1111/j.1369-1600.2007.00070.x] [Citation(s) in RCA: 994] [Impact Index Per Article: 58.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Conditioned place preference (CPP) continues to be one of the most popular models to study the motivational effects of drugs and non-drug treatments in experimental animals. This is obvious from a steady year-to-year increase in the number of publications reporting the use this model. Since the compilation of the preceding review in 1998, more than 1000 new studies using place conditioning have been published, and the aim of the present review is to provide an overview of these recent publications. There are a number of trends and developments that are obvious in the literature of the last decade. First, as more and more knockout and transgenic animals become available, place conditioning is increasingly used to assess the motivational effects of drugs or non-drug rewards in genetically modified animals. Second, there is a still small but growing literature on the use of place conditioning to study the motivational aspects of pain, a field of pre-clinical research that has so far received little attention, because of the lack of appropriate animal models. Third, place conditioning continues to be widely used to study tolerance and sensitization to the rewarding effects of drugs induced by pre-treatment regimens. Fourth, extinction/reinstatement procedures in place conditioning are becoming increasingly popular. This interesting approach is thought to model certain aspects of relapse to addictive behavior and has previously almost exclusively been studied in drug self-administration paradigms. It has now also become established in the place conditioning literature and provides an additional and technically easy approach to this important phenomenon. The enormous number of studies to be covered in this review prevented in-depth discussion of many methodological, pharmacological or neurobiological aspects; to a large extent, the presentation of data had to be limited to a short and condensed summary of the most relevant findings.
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Affiliation(s)
- Thomas M Tzschentke
- Grünenthal GmbH, Preclinical Research and Development, Department of Pharmacology, Aachen, Germany.
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22
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Wu HE, Schwasinger ET, Terashvili M, Tseng LF. dextro-Morphine attenuates the morphine-produced conditioned place preference via the sigma(1) receptor activation in the rat. Eur J Pharmacol 2007; 562:221-6. [PMID: 17335800 PMCID: PMC1936970 DOI: 10.1016/j.ejphar.2007.01.083] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2006] [Revised: 01/11/2007] [Accepted: 01/30/2007] [Indexed: 11/18/2022]
Abstract
An unbiased conditioned place preference paradigm was used to evaluate the effect of dextro-morphine on the morphine-produced reward in male CD rats. Morphine sulfate (1-10 mg/kg) given intraperitoneally dose-dependently produced the conditioned place preference. Pretreatment with dextro-morphine at a dose from 0.1 to 3 microg/kg given subcutaneously dose-dependently attenuated the morphine-produced conditioned place preference. However, dextro-morphine at a higher dose 100 microg/kg did not affect the morphine-produced conditioned place preference. Thus, dextro-morphine pretreatment induces a U-shaped dose-response curve for attenuating the morphine-produced conditioned place preference. The attenuation of the morphine-produced conditioned place preference was reversed by the pretreatment with the sigma(1) receptor antagonist BD1047 (N-[2-(3,4-Dichlorophenyl)ethyl]-N-methyl-2-(dimethylamino)ethylamine dihydrobromide. dextro-Morphine or BD1047 given alone did not affect the baseline place conditioning. It is concluded that dextro-morphine attenuated the morphine-produced conditioned place preference via the sigma(1) receptor activation.
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Affiliation(s)
- Hsiang-en Wu
- Dept. of Anesthesiology, Medical College of Wisconsin, Milwaukee, Wisconsin
53226
| | - Emma T. Schwasinger
- Dept. of Anesthesiology, Medical College of Wisconsin, Milwaukee, Wisconsin
53226
| | - Maia Terashvili
- Dept. of Anesthesiology, Medical College of Wisconsin, Milwaukee, Wisconsin
53226
| | - Leon F. Tseng
- Dept. of Anesthesiology, Medical College of Wisconsin, Milwaukee, Wisconsin
53226
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23
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Abstract
This paper is the 27th consecutive installment of the annual review of research concerning the endogenous opioid system, now spanning over 30 years of research. It summarizes papers published during 2004 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, and the roles of these opioid peptides and receptors in pain and analgesia; stress and social status; tolerance and dependence; learning and memory; eating and drinking; alcohol and drugs of abuse; sexual activity and hormones, pregnancy, development and endocrinology; mental illness and mood; seizures and neurologic disorders; electrical-related activity and neurophysiology; general activity and locomotion; gastrointestinal, renal and hepatic functions; cardiovascular responses; respiration and thermoregulation; and immunological responses.
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Affiliation(s)
- Richard J Bodnar
- Department of Psychology and Neuropsychology Doctoral Sub-Program, Queens College, City University of New York, Flushing, NY 11367, USA.
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24
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Kosson P, Bonney I, Carr DB, Lipkowski AW. Endomorphins interact with tachykinin receptors. Peptides 2005; 26:1667-9. [PMID: 16112408 DOI: 10.1016/j.peptides.2005.02.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2004] [Revised: 02/02/2005] [Accepted: 02/03/2005] [Indexed: 11/20/2022]
Abstract
Soon after the discovery of endomorphins several studies indicated differences between pharmacological effects of endomorphins and other MOR selective ligands, as well as differences between the effects of endomorphin I and endomorphin II. We now propose that these differences are the result of an additional non-opioid property of endomorphins, namely, their weak antagonist properties with respect to tachykinin NK1 and NK1 receptors.
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MESH Headings
- Animals
- Binding, Competitive
- CHO Cells
- Cell Membrane/metabolism
- Cricetinae
- Cricetulus
- Guinea Pigs
- Humans
- Ileum/drug effects
- Ileum/physiology
- In Vitro Techniques
- Molecular Structure
- Neurokinin-1 Receptor Antagonists
- Oligopeptides/chemistry
- Oligopeptides/metabolism
- Peptide Fragments/pharmacology
- Radioligand Assay
- Receptors, Neurokinin-1/genetics
- Receptors, Neurokinin-1/metabolism
- Receptors, Neurokinin-2/antagonists & inhibitors
- Receptors, Neurokinin-2/genetics
- Receptors, Neurokinin-2/metabolism
- Receptors, Neurokinin-3/genetics
- Receptors, Neurokinin-3/metabolism
- Receptors, Opioid/metabolism
- Receptors, Tachykinin/antagonists & inhibitors
- Receptors, Tachykinin/metabolism
- Substance P/pharmacology
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Affiliation(s)
- Piotr Kosson
- Medical Research Centre, Polish Academy of Sciences, 02106 Warsaw, Poland
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25
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Burgdorf J, Panksepp J. The neurobiology of positive emotions. Neurosci Biobehav Rev 2005; 30:173-87. [PMID: 16099508 DOI: 10.1016/j.neubiorev.2005.06.001] [Citation(s) in RCA: 456] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2005] [Revised: 05/20/2005] [Accepted: 06/10/2005] [Indexed: 11/26/2022]
Abstract
Compared to the study of negative emotions such as fear, the neurobiology of positive emotional processes and the associated positive affect (PA) states has only recently received scientific attention. Biological theories conceptualize PA as being related to (i) signals indicating that bodies are returning to equilibrium among those studying homeostasis, (ii) utility estimation among those favoring neuroeconomic views, and (iii) approach and other instinctual behaviors among those cultivating neuroethological perspectives. Indeed, there are probably several distinct forms of positive affect, but all are closely related to ancient sub-neocortical limbic brain regions we share with other mammals. There is now a convergence of evidence to suggest that various regions of the limbic system, including especially ventral striatal dopamine systems are implemented in an anticipatory (appetitive) positive affective state. Dopamine independent mechanisms utilizing opiate and GABA receptors in the ventral striatum, amygdala and orbital frontal cortex are important in elaborating consummatory PA (i.e. sensory pleasure) states, and various neuropeptides mediate homeostatic satisfactions.
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Affiliation(s)
- Jeffrey Burgdorf
- Department of Psychology, J.P. Scott Center for Neuroscience Mind and Behavior, Bowling Green State University, Bowling Green, OH 43403, USA
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26
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Wu HE, MacDougall RS, Clithero AD, Leitermann RJ, Terashvili M, Tseng LF. Opposite conditioned place preference responses to endomorphin-1 and endomorphin-2 in the mouse. Neurosci Lett 2004; 365:157-61. [PMID: 15246539 DOI: 10.1016/j.neulet.2004.03.093] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2003] [Revised: 03/28/2004] [Accepted: 03/31/2004] [Indexed: 10/26/2022]
Abstract
An unbiased conditioned place preference paradigm was used to evaluate the reward effect of selective endogenous mu-opioid ligands, endomorphin-1 and endomorphin-2, in male CD-1 mice. Pre- and post-conditioning free-movement were measured on day 1 and day 5, respectively. Conditioning sessions were conducted twice daily from day 2 through day 4 consisting of the alternate injection of conditioning drug or vehicle. Intracerebroventricular (i.c.v.) injection of endomorphin-1 (0.3-10 microg) induced place preference in a dose-dependent manner; whereas, endomorphin-2 (1-10 microg) dose-dependently induced place aversion. Both endomorphin-1-induced place preference and endomorphin-2-induced place aversion were blocked by pretreatment i.c.v. with mu-opioid receptor antagonist, beta-funaltrexamine. Selective delta-opioid receptor antagonist, naltrindole, co-administered i.c.v. with endomorphin-1 or endomorphin-2 did not affect reward effect. However, endomorphin-2-induced place aversion, but not endomorphin-1-induced place preference, was blocked by the i.c.v.-administered selective kappa-opioid receptor antagonist, WIN 44,441-3. It is concluded that endomorphin-1 produces conditioned place preference, which is mediated by the stimulation of mu-, but not delta- or kappa-opioid receptors, while endomorphin-2 produces conditioned place aversion, which is mediated by the stimulation of mu- and kappa-, but not delta-opioid receptors.
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MESH Headings
- Animals
- Azocines/pharmacology
- Conditioning, Operant/drug effects
- Injections, Intraventricular
- Ligands
- Male
- Mice
- Naltrexone/analogs & derivatives
- Naltrexone/pharmacology
- Oligopeptides/administration & dosage
- Oligopeptides/metabolism
- Oligopeptides/pharmacology
- Receptors, Opioid, delta/antagonists & inhibitors
- Receptors, Opioid, kappa/antagonists & inhibitors
- Receptors, Opioid, mu/antagonists & inhibitors
- Receptors, Opioid, mu/metabolism
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Affiliation(s)
- Hsiang-en Wu
- Department of Anesthesiology, Medical College of Wisconsin, Medical Education Building, M4308 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
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