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Bielecka-Papierz G, Serefko A, Szopa A, Talarek S, Wróbel A, Szewczyk B, Radziwoń-Zaleska M, Kołtun-Jasion M, Poleszak E. The role of the L-arginine-NO-cGMP-dependent pathway in the development of sensitization to mephedrone effects on the locomotor activity in mice. Behav Brain Res 2023; 437:114103. [PMID: 36089098 DOI: 10.1016/j.bbr.2022.114103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2021] [Revised: 09/04/2022] [Accepted: 09/05/2022] [Indexed: 10/14/2022]
Abstract
Mephedrone, a popular psychostimulating substance widely used illegally in recreational purposes, exerts in rodents that regularly and intermittently were exposed to it a sensitized response to the drug. Behavioral sensitization is one of experimental models of drug dependency/abuse liability. In the present study we evaluated a potential involvement of the L-arginine-NO-cGMP pathway in the development of sensitization to the mephedrone-induced hyperlocomotion. Locomotor activity was measured automatically and experiments were performed on male Albino Swiss mice. We demonstrated that a 5-day administration of 7-nitroindazole (10 or 20 mg/kg/day) and L-NAME (50 mg/kg/day) suppressed the development of sensitization to the mephedrone-induced hyperlocomotion. As for L-arginine (125 or 250 mg/kg/day) and methylene blue (5 or 10 mg/kg/day) the obtained outcomes are inconclusive. Furthermore, the lower dose of L-NAME (25 mg/kg/day) surprisingly potentiated the development of sensitization to the mephedrone-induced effects on the spontaneous locomotor activity in mice. In conclusion, our data demonstrated that modulators of the L-arginine-NO-cGMP pathway may differently affect the development of sensitization to the locomotor stimulant effects of mephedrone. Inhibition of neuronal nitric oxide synthase (NOS) seems to prevent this process quite profoundly, non-selective inhibition of NOS may have a dual effect, whereas inhibition of soluble guanylate cyclase may only partially suppress the development of sensitization to the mephedrone-induced effects.
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Affiliation(s)
- Gabriela Bielecka-Papierz
- Chair and Department of Applied and Social Pharmacy, Medical University of Lublin, 1 Chodźki Street, 20-093 Lublin, Poland.
| | - Anna Serefko
- Laboratory of Preclinical Testing, Chair and Department of Applied and Social Pharmacy, Medical University of Lublin, 1 Chodźki Street, 20-093 Lublin, Poland.
| | - Aleksandra Szopa
- Laboratory of Preclinical Testing, Chair and Department of Applied and Social Pharmacy, Medical University of Lublin, 1 Chodźki Street, 20-093 Lublin, Poland
| | - Sylwia Talarek
- Department of Pharmacology and Pharmacodynamics, Medical University of Lublin, 4a Chodźki Street, 20-093 Lublin, Poland
| | - Andrzej Wróbel
- Second Department of Gynecology, Medical University of Lublin, 8 Jaczewskiego Street, 20-090 Lublin, Poland
| | - Bernadeta Szewczyk
- Department of Neurobiology, Polish Academy of Sciences, Maj Institute of Pharmacology, 12 Smętna Street, 31-343 Kraków, Poland
| | - Maria Radziwoń-Zaleska
- Department of Psychiatry, Medical University of Warsaw, 27 Nowowiejska Street, 00-665 Warsaw, Poland
| | - Małgorzata Kołtun-Jasion
- Department of Pharmacognosy and Molecular Basis of Phytotherapy, Medical University of Warsaw, 02-097 Warsaw, Poland
| | - Ewa Poleszak
- Laboratory of Preclinical Testing, Chair and Department of Applied and Social Pharmacy, Medical University of Lublin, 1 Chodźki Street, 20-093 Lublin, Poland.
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Dunigan AI, Roseberry AG. Actions of feeding-related peptides on the mesolimbic dopamine system in regulation of natural and drug rewards. ADDICTION NEUROSCIENCE 2022; 2:100011. [PMID: 37220637 PMCID: PMC10201992 DOI: 10.1016/j.addicn.2022.100011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The mesolimbic dopamine system is the primary neural circuit mediating motivation, reinforcement, and reward-related behavior. The activity of this system and multiple behaviors controlled by it are affected by changes in feeding and body weight, such as fasting, food restriction, or the development of obesity. Multiple different peptides and hormones that have been implicated in the control of feeding and body weight interact with the mesolimbic dopamine system to regulate many different dopamine-dependent, reward-related behaviors. In this review, we summarize the effects of a selected set of feeding-related peptides and hormones acting within the ventral tegmental area and nucleus accumbens to alter feeding, as well as food, drug, and social reward.
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Affiliation(s)
- Anna I. Dunigan
- Department of Biology and Neuroscience Institute, Georgia State University, Atlanta, GA 30303, USA
| | - Aaron G. Roseberry
- Department of Biology and Neuroscience Institute, Georgia State University, Atlanta, GA 30303, USA
- Neuroscience Institute, Georgia State University, Atlanta, GA 30303, USA
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Novoa C, Solano JL, Ballesteros-Acosta HN, Lamprea MR, Ortega LA. Nicotine Differentially Modulates Emotional-Locomotor Interactions for Adult or Adolescent Rats. REVISTA COLOMBIANA DE PSICOLOGÍA 2022. [DOI: 10.15446/rcp.v31n1.89822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Previous research has shown that exposure to nicotine and other drugs of abuse stimulate dopaminergic neurons in the mesolimbic circuit. Sustained activation of this circuit by prolonged exposure to drugs promotes locomotor sensitization. However, there are inconsistent reports about nicotine-induced locomotor sensitization when assessed among different developmental stages. We evaluated exploratory behavior on specific areas of the open field as an indicator of behavioral disinhibition and general locomotor activity as an indicator of nicotine-induced locomotor sensitization, to further explore the mechanisms underlying behavioral adaptations to nicotine exposure in animals from different developmental stages. We found that while adolescent and adult rats are equally responsive to nicotine-induced locomotor sensitization, nicotine disrupts inhibition of risk-related behavior only in adolescent rats. Together, our results suggest that chronic daily exposure to nicotine promotes potentiation of its stimulant effects on locomotor activity. In adolescents, this effect is accompanied by a decreased capacity to inhibit risk-related behaviors under the acute effect of the drug.
How to cite this article: Novoa, C., Solano, J. L., Ballesteros-Acosta, H., Lamprea, R. M., & Ortega, L. A. (2021). Nicotine Differentially Modulates Emotional-Locomotor Interactions for Adult or Adolescent Rats. Revista Colombiana de Psicología, 31(1), 13-22. https://doi.org/10.15446/rcp.v31n1.89822
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Schroeder LE, Leinninger GM. Role of central neurotensin in regulating feeding: Implications for the development and treatment of body weight disorders. Biochim Biophys Acta Mol Basis Dis 2017; 1864:900-916. [PMID: 29288794 DOI: 10.1016/j.bbadis.2017.12.036] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 12/11/2017] [Accepted: 12/26/2017] [Indexed: 02/06/2023]
Abstract
The peptide neurotensin (Nts) was discovered within the brain over 40years ago and is implicated in regulating analgesia, body temperature, blood pressure, locomotor activity and feeding. Recent evidence suggests, however, that these disparate processes may be controlled via specific populations of Nts neurons and receptors. The neuronal mediators of Nts anorectic action are now beginning to be understood, and, as such, modulating specific Nts pathways might be useful in treating feeding and body weight disorders. This review considers mechanisms through which Nts normally regulates feeding and how disruptions in Nts signaling might contribute to the disordered feeding and body weight of schizophrenia, Parkinson's disease, anorexia nervosa, and obesity. Defining how Nts specifically mediates feeding vs. other aspects of physiology will inform the design of therapeutics that modify body weight without disrupting other important Nts-mediated physiology.
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Affiliation(s)
- Laura E Schroeder
- Department of Physiology, Michigan State University, East Lansing, MI 48823, United States
| | - Gina M Leinninger
- Department of Physiology, Michigan State University, East Lansing, MI 48823, United States.
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Pittenger ST, Swalve N, Chou S, Smith MD, Hoonakker AJ, Pudiak CM, Fleckenstein AE, Hanson GR, Bevins RA. Sex differences in neurotensin and substance P following nicotine self-administration in rats. Synapse 2016; 70:336-46. [PMID: 27074301 DOI: 10.1002/syn.21907] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Revised: 03/21/2016] [Accepted: 04/08/2016] [Indexed: 02/02/2023]
Abstract
Investigator-administered nicotine alters neurotensin and substance P levels in Sprague-Dawley rats. This finding suggested a role of the dopamine-related endogenous neuropeptides in nicotine addiction. We sought to extend this observation by determining the responses of neurotensin and substance P systems (assessed using radioimmunoassay) in male and female rats following nicotine self-administration (SA). Male and female Sprague-Dawley were trained to self-administer nicotine, or receive saline infusions yoked to a nicotine-administering rat during daily sessions (1-h; 21 days). Brains were extracted 3 h after the last SA session. Nicotine SA increased tissue levels of neurotensin in the males in the anterior and posterior caudate, globus pallidus, frontal cortex, nucleus accumbens core and shell, and ventral tegmental area. Nicotine SA also increased tissue levels of neurotensin in the females in the anterior caudate, globus pallidus, nucleus accumbens core and shell, but not in the posterior caudate, frontal cortex, or ventral tegmental area. There were fewer sex differences observed in the substance P systems. Nicotine SA increased tissue levels of substance P in both the males and females in the posterior caudate, globus pallidus, frontal cortex, nucleus accumbens shell, and ventral tegmental area. A sex difference was observed in the nucleus accumbens core, where nicotine SA increased tissue levels of substance P in the males, yet decreased levels in the females. The regulation of neuropeptides following nicotine SA may play a role in the susceptibility to nicotine dependence in females and males. Synapse 70:336-346, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Steven T Pittenger
- Department of Psychology, University of Nebraska-Lincoln, 238 Burnett Hall, Lincoln, Nebraska, 68588-0308
| | - Natashia Swalve
- Department of Psychology, University of Nebraska-Lincoln, 238 Burnett Hall, Lincoln, Nebraska, 68588-0308
| | - Shinnyi Chou
- Department of Psychology, University of Nebraska-Lincoln, 238 Burnett Hall, Lincoln, Nebraska, 68588-0308
| | - Misty D Smith
- School of Dentistry, University of Utah, 530 so. Wakara Way, Salt Lake City, Utah, 84108.,Department of Pharmacology and Toxicology, University of Utah, Skaggs Hall, Salt Lake City, Utah, 84112
| | - Amanda J Hoonakker
- School of Dentistry, University of Utah, 530 so. Wakara Way, Salt Lake City, Utah, 84108
| | - Cindy M Pudiak
- Department of Psychology, University of Nebraska-Lincoln, 238 Burnett Hall, Lincoln, Nebraska, 68588-0308
| | - Annette E Fleckenstein
- School of Dentistry, University of Utah, 530 so. Wakara Way, Salt Lake City, Utah, 84108
| | - Glen R Hanson
- School of Dentistry, University of Utah, 530 so. Wakara Way, Salt Lake City, Utah, 84108.,Department of Pharmacology and Toxicology, University of Utah, Skaggs Hall, Salt Lake City, Utah, 84112
| | - Rick A Bevins
- Department of Psychology, University of Nebraska-Lincoln, 238 Burnett Hall, Lincoln, Nebraska, 68588-0308
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Ferraro L, Tiozzo Fasiolo L, Beggiato S, Borelli AC, Pomierny-Chamiolo L, Frankowska M, Antonelli T, Tomasini MC, Fuxe K, Filip M. Neurotensin: A role in substance use disorder? J Psychopharmacol 2016; 30:112-27. [PMID: 26755548 DOI: 10.1177/0269881115622240] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Neurotensin is a tridecapeptide originally identified in extracts of bovine hypothalamus. This peptide has a close anatomical and functional relationship with the mesocorticolimbic and nigrostriatal dopamine system. Neural circuits containing neurotensin were originally proposed to play a role in the mechanism of action of antipsychotic agents. Additionally, neurotensin-containing pathways were demonstrated to mediate some of the rewarding and/or sensitizing properties of drugs of abuse.This review attempts to contribute to the understanding of the role of neurotensin and its receptors in drug abuse. In particular, we will summarize the potential relevance of neurotensin, its related compounds and neurotensin receptors in substance use disorders, with a focus on the preclinical research.
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Affiliation(s)
- Luca Ferraro
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy Laboratory for Technologies of Advanced Therapies (LTTA), University of Ferrara, Ferrara, Italy
| | - Laura Tiozzo Fasiolo
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Sarah Beggiato
- Department of Medical Sciences, University of Ferrara, Ferrara, Italy
| | - Andrea C Borelli
- Department of Medical Sciences, University of Ferrara, Ferrara, Italy
| | | | - Malgorzata Frankowska
- Laboratory of Drug Addiction Pharmacology, Institute of Pharmacology, Polish Academy of Sciences, Kraków, Poland
| | - Tiziana Antonelli
- Department of Medical Sciences, University of Ferrara, Ferrara, Italy
| | - Maria C Tomasini
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Kjell Fuxe
- Department of Medical Sciences, University of Ferrara, Ferrara, Italy
| | - Malgorzata Filip
- Laboratory of Drug Addiction Pharmacology, Institute of Pharmacology, Polish Academy of Sciences, Kraków, Poland
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7
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Elucidating the role of neurotensin in the pathophysiology and management of major mental disorders. Behav Sci (Basel) 2014; 4:125-153. [PMID: 25379273 PMCID: PMC4219245 DOI: 10.3390/bs4020125] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Revised: 05/15/2014] [Accepted: 05/21/2014] [Indexed: 12/30/2022] Open
Abstract
Neurotensin (NT) is a neuropeptide that is closely associated with, and is thought to modulate, dopaminergic and other neurotransmitter systems involved in the pathophysiology of various mental disorders. This review outlines data implicating NT in the pathophysiology and management of major mental disorders such as schizophrenia, drug addiction, and autism. The data suggest that NT receptor analogs have the potential to be used as novel therapeutic agents acting through modulation of neurotransmitter systems dys-regulated in these disorders.
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8
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Neurotensin agonist attenuates nicotine potentiation to cocaine sensitization. Behav Sci (Basel) 2014; 4:42-52. [PMID: 25379267 PMCID: PMC4219249 DOI: 10.3390/bs4010042] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Revised: 01/13/2014] [Accepted: 01/14/2014] [Indexed: 12/17/2022] Open
Abstract
Tobacco usage typically precedes illicit drug use in adolescent and young adult populations. Several animal studies suggest nicotine increases the risk for subsequent cocaine abuse, and may be a negative prognostic factor for treatment of cocaine addiction; i.e., a “gateway drug”. Neurotensin (NT) is a 13-amino acid neuropeptide that modulates dopamine, acetylcholine, glutamate, and GABA neurotransmission in brain reward pathways. NT69L, a NT(8-13) analog, blocks behavioral sensitization (an animal model for psychostimulant addiction) to nicotine, and nicotine self-administration in rats. The present study tested the effect of NT69L on the potentiating effects of nicotine on cocaine-induced locomotor sensitization. Male Wistar rats were injected daily for seven days with nicotine or saline (control) followed by four daily injections of cocaine. NT69L was administered 30 min prior to the last cocaine injection. Behavior was recorded with the use of activity chambers. Subchronic administration of nicotine enhanced cocaine-induced behavioral sensitization in Wistar rats, consistent with an hypothesized gateway effect. These behavioral effects of cocaine were attenuated by pretreatment with NT69L. The effect of the neurotensin agonist on cocaine sensitization in the nicotine treated group indicated a possible therapeutic effect for cocaine addiction, even in the presence of enhanced behavioral sensitization induced by nicotine.
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9
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Gozen O, Balkan B, Yildirim E, Koylu EO, Pogun S. The epigenetic effect of nicotine on dopamine D1 receptor expression in rat prefrontal cortex. Synapse 2013; 67:545-52. [PMID: 23447334 DOI: 10.1002/syn.21659] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Accepted: 02/22/2013] [Indexed: 12/14/2022]
Abstract
Nicotine is a highly addictive drug and exerts its effect partially through causing dopamine release, thereby increasing intrasynaptic dopamine levels in the brain reward systems. Dopaine D1 receptor (DRD1) mRNAs and receptors are localized in reward-related brain regions, which receive cholinergic input. The aim of this study is to evaluate whether nicotine administration affects the expression of DRD1s, and if so, whether epigenetic mechanisms, such as histone acetylation, are involved. Twenty Male Sprague Dawley rats received nicotine (0.4 mg/kg/day, s.c.) or saline injections for 15 days. After nicotine/saline treatment, rats were perfused with saline; prefrontal cortex (PFC), corpus striatum (STR), and ventral tegmental area (VTA) were dissected. Homogenates were divided into two parts for total RNA isolation and histone H4 acetylation studies. DRD1 mRNA expression was significantly higher in the PFC of the nicotine-treated group compared with controls; similar trends were observed in the VTA and STR. To study epigenetic regulation, the 2kb upstream region of the DRD1 gene promoter was investigated for histone H4 acetylation in PFC samples. After chromatin immunoprecipitation with anti-acetyl histone H4 antibody, we found an increase in histone acetylation by two different primer pairs which amplified the -1365 to -1202 (P < 0.005) and -170 to +12 (P < 0.05) upstream regions of the DRD1 promoter. Our results suggest that intermittent subcutaneous nicotine administration increases the expression of DRD1 mRNA in the PFC of rats, and this increase may be due to changes in histone H4 acetylation of the 2kb promoter of the DRD1 gene.
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Affiliation(s)
- Oguz Gozen
- Ege University School of Medicine Department of Physiology, Izmir, Turkey.
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10
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Boules M, Li Z, Smith K, Fredrickson P, Richelson E. Diverse roles of neurotensin agonists in the central nervous system. Front Endocrinol (Lausanne) 2013; 4:36. [PMID: 23526754 PMCID: PMC3605594 DOI: 10.3389/fendo.2013.00036] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2012] [Accepted: 03/06/2013] [Indexed: 01/10/2023] Open
Abstract
Neurotensin (NT) is a tridecapeptide that is found in the central nervous system (CNS) and the gastrointestinal tract. NT behaves as a neurotransmitter in the brain and as a hormone in the gut. Additionally, NT acts as a neuromodulator to several neurotransmitter systems including dopaminergic, sertonergic, GABAergic, glutamatergic, and cholinergic systems. Due to its association with such a wide variety of neurotransmitters, NT has been implicated in the pathophysiology of several CNS disorders such as schizophrenia, drug abuse, Parkinson's disease (PD), pain, central control of blood pressure, eating disorders, as well as, cancer and inflammation. The present review will focus on the role that NT and its analogs play in schizophrenia, endocrine function, pain, psychostimulant abuse, and PD.
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Affiliation(s)
- Mona Boules
- Neuropsychopharmacology Laboratory, Department of Neuroscience, Mayo Clinic FloridaJacksonville, FL, USA
- *Correspondence: Mona Boules, Neuropsychopharmacology Laboratory, Department of Neuroscience, Mayo Clinic, 4500 San Pablo Road, Jacksonville, FL 32224, USA. e-mail:
| | - Zhimin Li
- Neuropsychopharmacology Laboratory, Department of Neuroscience, Mayo Clinic FloridaJacksonville, FL, USA
| | - Kristin Smith
- Neuropsychopharmacology Laboratory, Department of Neuroscience, Mayo Clinic FloridaJacksonville, FL, USA
| | - Paul Fredrickson
- Neuropsychopharmacology Laboratory, Department of Neuroscience, Mayo Clinic FloridaJacksonville, FL, USA
| | - Elliott Richelson
- Neuropsychopharmacology Laboratory, Department of Neuroscience, Mayo Clinic FloridaJacksonville, FL, USA
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Listos J, Talarek S, Poleszak E, Wróbel A, Fidecka S. Attenuating effect of adenosine receptor agonists on the development of behavioral sensitization induced by sporadic treatment with morphine. Pharmacol Biochem Behav 2011; 98:356-61. [DOI: 10.1016/j.pbb.2011.01.019] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2010] [Revised: 01/17/2011] [Accepted: 01/24/2011] [Indexed: 10/18/2022]
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12
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Boules M, Oliveros A, Liang Y, Williams K, Shaw A, Robinson J, Fredrickson P, Richelson E. A neurotensin analog, NT69L, attenuates intravenous nicotine self-administration in rats. Neuropeptides 2011; 45:9-16. [PMID: 21047685 DOI: 10.1016/j.npep.2010.09.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2010] [Revised: 09/22/2010] [Accepted: 09/28/2010] [Indexed: 11/20/2022]
Abstract
NT69L is a neurotensin analog that blocks nicotine-induced locomotor activity and has sustained efficacy in a rat model of nicotine-induced sensitization when administered peripherally. Additionally, NT69L attenuates food-reinforcement in rats. The present study tested the effect of acute administration of NT69L on nicotine self-infusion in Sprague-Dawley rats. Rats were trained to self-infuse nicotine intravenously (0.03mg/kg per infusion) following operant training. Once the rats acquired stable responding to nicotine self-infusion they were pretreated with NT69L (1mg/kg, i.p.) or saline 30min before being assessed for nicotine self-infusion. Pretreatment with NT69L significantly attenuated nicotine self-infusion under FR1 (fixed ratio of 1) and FR5 schedule of reinforcement as compared to saline pretreatment. Control rats that were response-independent "yoked" as well as rats that self-infused saline or NT69L showed minimal responses, indicating that nicotine served as a reinforcer. Additionally, NT69L modulated serum corticosterone; brain norepinephrine serotonin; and dopamine receptors mRNA levels altered in the nicotine self-infused rats after a 24h withdrawal period. Pretreatment with NT69L significantly decreased the nicotine-induced increase in serum corticosterone levels and striatal norepinephrine and increased the nicotine-induced reduction in serotonin in both the striatum and the prefrontal cortex (PFC). NT69L might modulate dopamine neurotransmission implicated in the reinforcing effects of nicotine by modulating tyrosine hydroxylase and dopamine receptor mRNA levels in the PFC and striatum. These data support further study of the effects of NT analogs on attenuating the reinforcing effects of psychostimulants.
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Affiliation(s)
- Mona Boules
- Neuropsychopharmacology Laboratory, Mayo Clinic Jacksonville, 4500 San Pablo Road, Jacksonville, FL 32224, USA.
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13
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Li Z, Boules M, Richelson E. NT69L blocks ethanol-induced increase of dopamine and glutamate levels in striatum of mouse. Neurosci Lett 2010; 487:322-4. [PMID: 20974215 DOI: 10.1016/j.neulet.2010.10.048] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2010] [Revised: 10/05/2010] [Accepted: 10/16/2010] [Indexed: 12/16/2022]
Abstract
Recent study shows that NT69L, an analog of neurotensin (NT) (8-13), reduces ethanol consumption and preference in mice through modulation of neurotensin receptor subtype one. The current study showed that NT69L significantly decreased ethanol-induced increase of dopamine and glutamate levels in striatum of mouse. These data suggest that NT69L prevents ethanol consumption through the modulation of both dopaminergic and glutamatergic systems implicated in ethanol addiction. NT agonists may provide novel treatment for alcohol addiction.
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Affiliation(s)
- Zhimin Li
- Neuroscience Laboratory and Mayo Foundation for Medical Education and Research, Mayo Clinic, 4500 San Pablo Road, Jacksonville, FL 32224, USA.
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14
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Liang Y, Boules M, Shaw AM, Williams K, Fredrickson P, Richelson E. Effect of a novel neurotensin analog, NT69L, on nicotine-induced alterations in monoamine levels in rat brain. Brain Res 2008; 1231:6-15. [DOI: 10.1016/j.brainres.2008.07.037] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2008] [Revised: 07/08/2008] [Accepted: 07/09/2008] [Indexed: 10/21/2022]
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15
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DiFranza JR, Ursprung WWSA. The latency to the onset of nicotine withdrawal: a test of the sensitization-homeostasis theory. Addict Behav 2008; 33:1148-53. [PMID: 18547736 DOI: 10.1016/j.addbeh.2008.04.011] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2007] [Revised: 04/03/2008] [Accepted: 04/29/2008] [Indexed: 11/30/2022]
Abstract
The latency to withdrawal (LTW) is the expired time between the last cigarette and when the smoker feels the need to smoke again. The sensitization-homeostasis theory predicts that the LTW is inversely related to the frequency and duration of smoking such that more frequent cigarette consumption and a longer history of tobacco use will be associated with a shorter LTW. An anonymous cross-sectional survey of 1055 10th and 11th grade students of mixed ethnicity was conducted in two schools using self-completed questionnaires. Participants were asked "After you have smoked a cigarette, how long can you go before you feel you need to smoke again?" Of 162 current smokers, 73.5% reported a regular need to smoke and a LTW. Reported values for the LTW ranged from .05 h to "3 weeks or more." Monthly cigarette consumption ranged from 1 to 895. The LTW correlated inversely with monthly cigarette consumption (Kendall's tau b=-.53, P<.001) and the duration of smoking (Kendall's tau b=-.25, P<.001) as predicted by the sensitization-homeostasis theory.
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Affiliation(s)
- Joseph R DiFranza
- Department of Family Medicine and Community Health, University of Massachusetts Medical School, Worcester, Massachusetts 01655, USA.
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16
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Listos J, Talarek S, Fidecka S. Adenosine receptor agonists attenuate the development of diazepam withdrawal-induced sensitization in mice. Eur J Pharmacol 2008; 588:72-7. [PMID: 18466897 DOI: 10.1016/j.ejphar.2008.04.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2007] [Revised: 03/19/2008] [Accepted: 04/02/2008] [Indexed: 10/22/2022]
Abstract
In the present study, the effects of adenosine agonists on the development of sensitization to withdrawal signs precipitated after sporadic treatment with diazepam, in mice, were investigated. To obtain the sensitization, the animals were divided into groups: continuously and sporadically treated with diazepam (15.0 mg/kg, s.c.). The adenosine receptor agonists (CPA, CGS 21,680 and NECA) were administered in sporadically diazepam treated mice during two diazepam-free periods. Concomitant administration of pentetrazole (55.0 mg/kg, s.c.) with flumazenil (5.0 mg/kg, i.p.) after the last injection of diazepam or vehicle, induced the withdrawal signs, such as clonic seizures, tonic convulsion and death episodes. The major finding of our experiments is attenuation of withdrawal signs in sensitized mice, inducing by all adenosine agonists. Only higher dose of CPA produced significantly decreased the number of withdrawal incidents, while both used doses of CGS 21,680 and NECA produced more clear effects. These results support the hypothesis that adenosinergic system is involved in the mechanisms of sensitization to the benzodiazepine withdrawal signs, and adenosine A(2A) receptors play more important role in that process.
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Affiliation(s)
- Joanna Listos
- Department of Pharmacology and Pharmacodynamics, Medical University of Lublin, Staszica 4, 20-081 Lublin, Poland.
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17
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Alburges ME, Hoonakker AJ, Hanson GR. Nicotinic and dopamine D2 receptors mediate nicotine-induced changes in ventral tegmental area neurotensin system. Eur J Pharmacol 2007; 573:124-32. [PMID: 17689525 PMCID: PMC2707996 DOI: 10.1016/j.ejphar.2007.06.063] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2006] [Revised: 06/14/2007] [Accepted: 06/18/2007] [Indexed: 11/30/2022]
Abstract
Neuropeptides have been implicated in the psychopathology of stimulants of abuse. Neurotensin is a neuropeptide associated with the regulation of the nigrostriatal and mesolimbic dopamine pathways. In addition, the ventral tegmental area, a midbrain region implicated in the rewarding effects of most, if not all, addictive drugs, appears to be a particularly critical target for nicotine action. Because neurotensin has been linked with both mesolimbic and mesocortical dopamine function, we examined the impact of nicotine treatment on central nervous neurotensin systems by measuring changes in neurotensin tissue content because it has been shown that such changes reflect alterations in release and activity of this peptide system. Male Sprague-Dawley rats received multiple administrations of (+/-) nicotine 4.0 mg/kg/day (0.8 mg/kg, i.p.; 5 x 2-h intervals) in the presence or absence of selective dopamine receptor antagonists (dopamine D(1); SCH 23390 or dopamine D(2); eticlopride) or two doses of the non-selective nicotinic acetylcholine receptor antagonist (mecamylamine; 3.0 and 6.0 mg/kg, s.c.). The nicotine treatment significantly decreased neurotensin-like immunoreactivity content in the ventral tegmental area, as well as related regions such as prefrontal cortex, substantia nigra, and anterior striatal region 12-18 h after drug treatment, but not the nucleus accumbens. The nicotine-mediated decrease in the neurotensin-like immunoreactivity of the ventral tegmental area was selectively blocked by a specific dopamine D(2), but not a dopamine D(1), receptor antagonist, while mecamylamine attenuated at the low (3.0 mg/kg) and completely blocked at high (6.0 mg/kg) dose this nicotine effect. These findings with previous studies, suggest that nicotine-mediated dopamine release activates D(2) receptors which in turn increases neurotensin release, turnover and acutely reduces tissue levels in the ventral tegmental area and other limbic and basal ganglia structures.
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Affiliation(s)
- Mario E Alburges
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, Utah, USA.
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18
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Abstract
Neurotensin (NT) is a neuropeptide that, for decades, has been implicated in the biology of schizophrenia. It is closely associated with, and is thought to modulate, dopaminergic and other neurotransmitter systems involved in the pathophysiology of various neuropsychiatric diseases, including schizophrenia. This review outlines the neurochemistry and function of the NT system and the data implicating its role in schizophrenia. The data suggest that NT receptor agonists have the potential to be used as novel therapeutic agents for the treatment of schizophrenia, with the added benefits of (i) not causing weight gain, an adverse effect that is problematic with some of the currently used atypical antipsychotic drugs; and (ii) helping patients to stop smoking, a behaviour that is highly prevalent in those with schizophrenia.
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Affiliation(s)
- Mona Boules
- Neuropsychopharmacology Laboratory, Mayo Foundation for Medical Education and Research, Mayo Clinic Jacksonville, Florida 32224, USA.
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19
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Boules M, Iversen I, Oliveros A, Shaw A, Williams K, Robinson J, Fredrickson P, Richelson E. The neurotensin receptor agonist NT69L suppresses sucrose-reinforced operant behavior in the rat. Brain Res 2007; 1127:90-8. [PMID: 17113052 DOI: 10.1016/j.brainres.2006.10.025] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2006] [Revised: 10/02/2006] [Accepted: 10/04/2006] [Indexed: 10/23/2022]
Abstract
NT69L is a neurotensin analog that can be administered peripherally. It blocks amphetamine- and cocaine-induced hyperactivity in rats. It also blocks nicotine-induced locomotor activity and has shown sustained efficacy in a rat model of nicotine-induced sensitization. The present study tested the effect of NT69L on responding for sucrose reinforcement on a continuous reinforcement schedule (CRF) and incrementing (FR1-FR5) discrimination schedule. Male Sprague-Dawley rats, on restricted food intake, were trained to press a lever for sucrose pellets on a CRF and incrementing discrimination schedule of reinforcement. On the following day, the testing session was followed by an extinction session, where lever pressing was not reinforced. Immediately after extinction, a reversal to CRF was implemented to test for relapse. Trained rats were injected with NT69L (1 mg/kg) or saline 30 min before each testing session. Dopamine, tyrosine 3-hydroxylase, and dopamine receptor mRNA levels were determined. NT69L significantly suppressed the lever pressing behavior for sucrose reinforcement on CRF which measures the "hedonic" value of the reward. NT69L also suppressed sucrose self-administration on the incrementing discrimination schedule of reinforcement (FR3-FR5) that is analogous to the motivational incentive. Reversal to CRF was significantly reduced by pretreatment with NT69L. The suppression of sucrose self-administration behavior by pretreatment with NT69L had a pattern similar to that for extinction. The effect of NT69L on dopamine, tyrosine 3-hydroxylase, and dopamine receptor mRNA levels is discussed relative to changes occurring during extinction.
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MESH Headings
- Animals
- Behavior, Animal/drug effects
- Behavior, Animal/physiology
- Brain/drug effects
- Brain/metabolism
- Conditioning, Operant/drug effects
- Conditioning, Operant/physiology
- Dopamine/metabolism
- Extinction, Psychological/drug effects
- Extinction, Psychological/physiology
- Food Deprivation/physiology
- Male
- Neurotensin/analogs & derivatives
- Neurotensin/metabolism
- Neurotensin/pharmacology
- Peptide Fragments/pharmacology
- RNA, Messenger/drug effects
- RNA, Messenger/metabolism
- Rats
- Rats, Sprague-Dawley
- Receptors, Dopamine/metabolism
- Receptors, Neurotensin/agonists
- Receptors, Neurotensin/metabolism
- Reinforcement, Psychology
- Self Administration
- Sucrose/pharmacology
- Tyrosine 3-Monooxygenase/genetics
- Tyrosine 3-Monooxygenase/metabolism
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Affiliation(s)
- Mona Boules
- Mayo Foundation for Medical Education and Research and Mayo Clinic Jacksonville, 4500 San Pablo Road, Jacksonville, FL 32224, USA.
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20
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Boules M, Fredrickson P, Richelson E. Neurotensin agonists as an alternative to antipsychotics. Expert Opin Investig Drugs 2006; 14:359-69. [PMID: 15882113 DOI: 10.1517/13543784.14.4.359] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Neurotensin (NT) is a 13 amino acid neuropeptide that is found in the central nervous system and in the gastrointestinal tract. In brain, this peptide is prominently associated anatomically with dopaminergic, as well as other neurotransmitter systems. Based on animal studies, already decades old, researchers have hypothesised that NT receptor agonists will have antipsychotic properties in patients. However, to date no one has obtained a non-peptide NT receptor agonist. Therefore, there has been great interest in obtaining peptide analogues of NT, that, unlike NT resist degradation by peptidases and cross the blood-brain barrier, yet have the pharmacological characteristics of native NT, for therapeutic use in the treatment of schizophrenia, as well as other neuropsychiatric diseases such as Parkinson's disease and addiction to psychostimulants. In this review, we present the rationale for development of NT receptor agonists for treatment of certain central nervous system diseases, as well as a review of those peptide agonists that are in early stages of development.
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Affiliation(s)
- Mona Boules
- Neuropsychopharmacology Laboratory and Nicotine Dependence Center, Mayo Foundation for Medical Education and Research, 4500 San Pablo Road, Jacksonville, FL 32224, USA
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21
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Boules M, Fredrickson P, Richelson E. Bioactive analogs of neurotensin: focus on CNS effects. Peptides 2006; 27:2523-33. [PMID: 16882457 DOI: 10.1016/j.peptides.2005.12.018] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2005] [Accepted: 12/01/2005] [Indexed: 11/17/2022]
Abstract
Neurotensin (NT) is a 13-amino acid neuropeptide found in the central nervous system and in the gastrointestinal tract. It is closely associated anatomically with dopaminergic and other neurotransmitter systems, and evidence supports a role for NT agonists in the treatment of various neuropsychiatric disorders. However, NT is readily degraded by peptidases, so there is much interest in the development of stable NT agonists, that can be injected systemically, cross the blood-brain barrier (BBB), yet retains the pharmacological characteristics of native NT for therapeutic use in the treatment of diseases such as schizophrenia, Parkinson's disease and addiction.
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Affiliation(s)
- Mona Boules
- Neuropsychopharmacology Laboratory, Mayo Clinic, 4500 San Pablo Road, Jacksonville, FL 32224, USA.
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22
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Cáceda R, Kinkead B, Nemeroff CB. Neurotensin: role in psychiatric and neurological diseases. Peptides 2006; 27:2385-404. [PMID: 16891042 DOI: 10.1016/j.peptides.2006.04.024] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2005] [Accepted: 04/01/2006] [Indexed: 10/24/2022]
Abstract
Neurotensin (NT), an endogenous brain-gut peptide, has a close anatomical and functional relationship with the mesocorticolimbic and neostriatal dopamine system. Dysregulation of NT neurotransmission in this system has been hypothesized to be involved in the pathogenesis of schizophrenia. Additionally, NT containing circuits have been demonstrated to mediate some of the mechanisms of action of antipsychotic drugs, as well as the rewarding and/or sensitizing properties of drugs of abuse. NT receptors have been suggested to be novel targets for the treatment of psychoses or drug addiction.
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Affiliation(s)
- Ricardo Cáceda
- Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Suite 4000 WMRB, 101 Woodruff Circle, Atlanta, GA 30322 4990, USA.
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23
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Fernando WWSA, Wellman RJ, Difranza JR. The relationship between level of cigarette consumption and latency to the onset of retrospectively reported withdrawal symptoms. Psychopharmacology (Berl) 2006; 188:335-42. [PMID: 16953390 DOI: 10.1007/s00213-006-0497-x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2006] [Accepted: 06/22/2006] [Indexed: 11/25/2022]
Abstract
RATIONALE Subthreshold smokers (who smoke < or =5 cigarettes/day) experience withdrawal symptoms, yet they smoke less than is required to maintain serum nicotine levels. OBJECTIVES For study 1, our aim was to determine (1) if adult subthreshold smokers report withdrawal symptoms; (2) how they rate symptom severity; (3) the length of their latency to withdrawal symptoms; (4) and the relationship between level of cigarette consumption and latency to withdrawal. The aim of study 2 was to attempt to replicate the results of study 1 in a nationally representative sample and to compare subthreshold and threshold (> or =6 cigarettes/day) smokers. METHODS Study 1 was conducted through telephone interviews. Study 2 was conducted through secondary analysis of data from the National Youth Tobacco Survey (self-administered in schools). RESULTS In study 1, all subjects experienced withdrawal symptoms. The mean number of symptoms was 4.3; mean intensity of each symptom was >6 (1-10 scale). A quarter of the subjects could go for > or =2 days before experiencing withdrawal. More frequent smokers had a shorter latency to withdrawal (r=-0.43, p<0.001, n=36). In study 2, 63% of subthreshold smokers reported feeling at least one withdrawal symptom. Median latency to withdrawal was 168 h for subthreshold and 2 h for threshold smokers. A negative correlation between level of cigarette consumption and latency to withdrawal was observed for both groups. CONCLUSIONS Although subthreshold smokers experience significant withdrawal symptoms, they can smoke infrequently because symptoms may not appear for one to several days. Consistent with the sensitization-homeostasis theory, low doses of nicotine can suppress withdrawal symptoms over long periods.
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Affiliation(s)
- W W S A Fernando
- Department of Family Medicine and Community Health, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, MA, 01655, USA
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24
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Wang R, Boules M, Gollatz E, Williams K, Tiner W, Richelson E. Effects of 5 daily injections of the neurotensin-mimetic NT69L on the expression of neurotensin receptors in rat brain. ACTA ACUST UNITED AC 2005; 138:24-34. [PMID: 15878217 DOI: 10.1016/j.molbrainres.2005.03.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2004] [Revised: 03/11/2005] [Accepted: 03/27/2005] [Indexed: 11/25/2022]
Abstract
The effects of one or five daily intraperitoneal injections of a neurotensin (NT) receptor agonist NT69L (2 mg/kg, i.p.) on the expression of NT (NTS), dopamine 1 and 2 receptors, tyrosine hydroxylase, and DOPA decarboxylase using immunohistochemical and real-time PCR were investigated in rats. Except for the striatum, acute injection of NT69L did not affect neurotensin receptors as compared to saline control. However, 5 daily injections of NT69L resulted in down-regulation of both NTS-1 protein and mRNA levels in several brain regions with the striatum showing a dramatic decrease in NTS-1 expression (P<0.05). The down-regulation of NTS-1 in the striatum, hypothalamus, and substania nigra (SN) after 5 daily injections was confirmed by autoradiography. Acute injection of NT69L increased NTS-2 mRNA and protein level in prefrontal cortex (PFC). NTS-3 mRNA expression and protein levels were slightly down-regulated in hypothalamus, periaqueductal gray (PAG), and SN, though the difference was not significant. The results indicated a difference in the profile of NT receptors expression in response to NT69L. Tyrosine hydroxylase (TH) and DOPA decarboxylase (DDC) mRNA was significantly down-regulated in striatum but not in SN. Interestingly, Nurr 1, a transcriptional activator of TH, was dramatically up-regulated in striatum, but down-regulated in PFC, suggesting that different modulating mechanisms may participate in NT69L tolerance in different regions. The present results suggest that distinct NT receptors involved in the effects exerted by NT69L may contribute to the interactions of NT69L with both neural networks and cellular proteins.
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Affiliation(s)
- Rui Wang
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 200031, PR China
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25
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Fredrickson P, Boules M, Lin SC, Richelson E. Neurobiologic basis of nicotine addiction and psychostimulant abuse: a role for neurotensin? Psychiatr Clin North Am 2005; 28:737-51, 746. [PMID: 16122577 DOI: 10.1016/j.psc.2005.05.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Addiction to psychostimulant drugs such as nicotine, amphetamine, and cocaine is a serious public health problem for which there is a paucity of accepted forms of pharmacotherapy. Nicotine dependence has become more frequently associated with psychiatric illness in recent decades, and patients who have schizophrenia are at highest risk and have the poorest prognosis for stopping their addiction. Possible mechanisms for this association include self-medication, with nicotine attenuating attentional deficits and negative symptoms. Neurotensin has been postulated to be an endogenous neuroleptic, and the performance of neurotensin analogues in animal models of addiction makes such compounds intriguing candidates for treatment of addiction in high-risk psychiatric populations.
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Affiliation(s)
- Paul Fredrickson
- Department of Psychiatry and Psychology, Mayo Clinic College of Medicine, Jacksonville, FL 32224, USA.
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26
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Fantegrossi WE, Ko MCH, Woods JH, Richelson E. Antinociceptive, hypothermic, hypotensive, and reinforcing effects of a novel neurotensin receptor agonist, NT69L, in rhesus monkeys. Pharmacol Biochem Behav 2005; 80:341-9. [PMID: 15680187 DOI: 10.1016/j.pbb.2004.12.005] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2004] [Revised: 12/02/2004] [Accepted: 12/03/2004] [Indexed: 11/27/2022]
Abstract
Neurotensin (NT) is a tridecapeptide found in the nervous system, as well as elsewhere in the body. It has anatomic and functional relationships to dopaminergic neurons in brain. NT has been implicated in the actions of antipsychotic drugs and psychostimulants, and animal studies suggest that neurotensin directly injected into brain has reinforcing effects. Previously, we showed that one of our brain-penetrating analogs of neurotensin, NT69L (N-methyl-L-Arg, L-Lys, L-Pro, L-neo-Trp, L-tert-Leu, L-Leu), has many pharmacological effects in rats including antinociception, hypothermia, and blockade of the hyperactivity caused by psychostimulants (cocaine, D-amphetamine, and nicotine). Since these studies in rats suggest that this compound may have clinical use in humans, we were interested to know what effects NT69L had in primates. NT69L caused a potent antinociceptive effect against capsaicin (0.1 mg)-induced allodynia in 46 degrees C water in rhesus monkeys, inducing 40% of the maximal possible effect at an intravenous dosage of 0.03 mg/kg; its hypotensive effects precluded evaluation of higher dosages. Core temperature measured by rectal probe was modestly reduced at 0.01 and 0.03 mg/kg. In an intravenous self-administration procedure, NT69L was without reinforcing effects at any dose, including those that caused other pharmacological effects, and did not alter cocaine-maintained behavior when administered as a pretreatment.
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Affiliation(s)
- W E Fantegrossi
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI, USA
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27
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Wang R, Boules M, Tiner W, Richelson E. Effects of repeated injections of the neurotensin analog NT69L on dopamine release and uptake in rat striatum in vitro. Brain Res 2005; 1025:21-8. [PMID: 15464740 DOI: 10.1016/j.brainres.2004.07.069] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/09/2004] [Indexed: 11/24/2022]
Abstract
The effect of five daily intraperitoneal (i.p.) injections of NT69L on in vitro dopamine release, uptake, and [(3)H]NT binding in rat striatal tissue was investigated. NT69L perfusion increased K(+)-evoked and electrically evoked [(3)H]DA release. NT receptor-1 antagonist SR48692 inhibited the stimulatory effect of NT69L on K+-evoked [(3)H]DA release, but not on electrical depolarization. Pretreatment with NT69L, in vivo, daily for 5 days, did not cause significant change in K(+) evoked [(3)H]DA release, but reduced electrically evoked [(3)H]DA release induced by NT69L perfusion. Repeated perfusion with NT69L in vitro caused marked reduction on K(+)-evoked [(3)H]DA release and no change in electrically evoked [(3)H]DA release. [(3)H]NT binding was not significantly changed by one injection but was decreased after five injections of NT69L. Desensitization to the effects of NT69L in vitro was different depending upon whether tissue was preexposed to the compound in vivo or in vitro. These results provide further proof for the involvement of different NT receptor subtypes in mediating the effect of NT69L on dopamine release evoked by K(+) or electrical depolarization.
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Affiliation(s)
- Rui Wang
- Neuropsychopharmacology Laboratory, Mayo Foundation for Medical Education and Research, and Mayo Clinic Jacksonville, 4500 San Pablo Road, Jacksonville, FL 32224, USA
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28
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Abstract
Neurotensin (NT) is a neuropeptide found in the central nervous system and gastrointestinal tract. It is closely associated with dopaminergic and other neurotransmitter systems, and evidence supports a role for NT in various neuropsychiatric disorders. Because NT is readily degraded by peptidases, our group has developed various NT agonists that can be injected systemically, cross the blood brain barrier (BBB), yet retain the characteristics of native NT. The most widely studied and successful of these compounds, called NT69L, holds promise as a therapeutic agent for Parkinson's disease, schizophrenia, psychostimulant abuse and nicotine dependence, and serves as a tool to study the cellular and molecular effects of NT.
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Affiliation(s)
- Mona Boules
- Neuropsychopharmacology Laboratory, Mayo Clinic, 4500 San Pablo Road, Jacksonville, FL 32224, USA.
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29
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Liu X, Koren AO, Yee SK, Pechnick RN, Poland RE, London ED. Self-administration of 5-iodo-A-85380, a beta2-selective nicotinic receptor ligand, by operantly trained rats. Neuroreport 2003; 14:1503-5. [PMID: 12960773 DOI: 10.1097/00001756-200308060-00020] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
It is widely accepted that nicotine is the active ingredient of tobacco smoke that promotes tobacco dependence. Nicotine interacts with several subtypes of nicotinic acetylcholine receptors (nAChRs). In brain, it primarily targets nAChRs that contain beta2 and alpha4 subunits in combination and those composed of solely alpha7 subunits. The present study tested whether operantly trained rats would self-administer a ligand active at beta2-containing (i.e. not alpha7) nAChRs. Male Sprague-Dawley rats were trained to lever press for i.v. cocaine self-administration. After 2 weeks of cocaine washout, rats were given operant access to 5-iodo-A-85380 (5IA), a beta2-selective nAChR ligand, in daily 1 h sessions. The rats rapidly developed a stable level of 5IA self-administration behavior (unit dose = 5 nmol/kg/infusion). This finding suggests that interaction with beta2-containing nAChRs, without direct involvement of alpha7 receptors, can produce reinforcement and thereby can support self-administration behavior.
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Affiliation(s)
- Xiu Liu
- Department of Psychiatry, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA.
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30
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Fredrickson P, Boules M, Yerbury S, Richelson E. Novel neurotensin analog blocks the initiation and expression of nicotine-induced locomotor sensitization. Brain Res 2003; 979:245-8. [PMID: 12850594 DOI: 10.1016/s0006-8993(03)02895-6] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Neurotensin is a tridecapeptide that participates in regulation of dopaminergic pathways implicated in nicotine addiction. Previously, we showed that one of our brain-penetrating neurotensin analogs, NT69L, blocks nicotine-induced locomotor sensitization. The present work demonstrates that NT69L blocks both the initiation and the expression of sensitization. In addition chronic NT69L administration blocked the acute effects of nicotine on norepinephrine and serotonin in prefrontal cortex.
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Affiliation(s)
- Paul Fredrickson
- Nicotine Dependence Center, Mayo Foundation for Medical Education and Research, and Mayo Clinic Jacksonville, 32224, Jacksonville, FL, USA
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