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Straub CJ, Rusali LE, Kremiller KM, Riley AP. What We Have Gained from Ibogaine: α3β4 Nicotinic Acetylcholine Receptor Inhibitors as Treatments for Substance Use Disorders. J Med Chem 2023; 66:107-121. [PMID: 36440853 PMCID: PMC10034762 DOI: 10.1021/acs.jmedchem.2c01562] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
For decades, ibogaine─the main psychoactive alkaloid found in Tabernanthe iboga─has been investigated as a possible treatment for substance use disorders (SUDs) due to its purported ability to interrupt the addictive properties of multiple drugs of abuse. Of the numerous pharmacological actions of ibogaine and its derivatives, the inhibition of α3β4 nicotinic acetylcholine receptors (nAChRs), represents a probable mechanism of action for their apparent anti-addictive activity. In this Perspective, we examine several classes of compounds that have been discovered and developed to target α3β4 nAChRs. Specifically, by focusing on compounds that have proven efficacious in pre-clinical models of drug abuse and have been evaluated clinically, we highlight the promising potential of the α3β4 nAChRs as viable targets to treat a wide array of SUDs. Additionally, we discuss the challenges faced by the existing classes of α3β4 nAChR ligands that must be overcome to develop them into therapeutic treatments.
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Affiliation(s)
- Carolyn J Straub
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, Illinois 60612, United States
| | - Lisa E Rusali
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, Illinois 60612, United States
| | - Kyle M Kremiller
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, Illinois 60612, United States
| | - Andrew P Riley
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, Illinois 60612, United States
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2
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Gellner CA, Carreño D, Belluzzi JD, Leslie FM. Impact of tobacco smoke constituents on nicotine-seeking behavior in adolescent and adult male rats. Front Psychiatry 2023; 14:1096213. [PMID: 36815196 PMCID: PMC9939699 DOI: 10.3389/fpsyt.2023.1096213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Accepted: 01/17/2023] [Indexed: 02/09/2023] Open
Abstract
INTRODUCTION Given the rapid increase in teen vaping over recent years it is critical to understand mechanisms underlying addiction and relapse to tobacco use at this age. To evaluate the role of non-nicotine constituents in cigarette smoke, our lab has previously established a model of intravenous self-administration of aqueous cigarette smoke extract (CSE). We now compare the sensitivity of male adolescent and adult rats who have self-administered CSE or nicotine to reinstatement with the pharmacological stressor, yohimbine, with and without cues. METHODS Adolescents and adults, aged postnatal day (P) 34 and 84, were tested for the effect of yohimbine (0-2.5 mg/kg) on plasma corticosterone levels to establish a dose that was an effective stressor at both ages. Separate groups of animals were trained to lever press for food before beginning 1-hour drug self-administration sessions for nicotine or CSE (15 μg/kg/infusion nicotine content). Once stable responding was reached, drug was removed, and behavior extinguished. Drug-seeking behavior was reinstated with yohimbine, cues, or a combination of yohimbine and cues. RESULTS Although adolescents and adults showed different dose-responses for yohimbine-induced corticosterone release, a dose of 2.5 mg/kg increased stress hormone levels at both ages. Whereas both ages displayed similar responding for CSE and nicotine, adolescents self-administered more CSE and nicotine as compared to adults. Cues and cues + stress reinstated responding to a greater extent in animals that had self-administered CSE, regardless of age. DISCUSSION These findings suggest that non-nicotine tobacco smoke constituents influence later but not earlier stages of addiction in both adolescent and adult male rats.
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Affiliation(s)
- Candice A Gellner
- Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences, University of California, Irvine, Irvine, CA, United States
| | - Diana Carreño
- Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences, University of California, Irvine, Irvine, CA, United States
| | - James D Belluzzi
- Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences, University of California, Irvine, Irvine, CA, United States
| | - Frances M Leslie
- Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences, University of California, Irvine, Irvine, CA, United States
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Kim JS, Kim OH, Ryu IS, Kim YH, Jeon KO, Lim LN, Kim TW, Sohn S, Kim S, Seo JW, Choe ES, Jang EY. Challenge exposure to whole cigarette smoke condensate upregulates locomotor sensitization by stimulating α4β2 nicotinic acetylcholine receptors in the nucleus accumbens of rats. Pharmacol Biochem Behav 2022; 220:173469. [PMID: 36183870 DOI: 10.1016/j.pbb.2022.173469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 09/24/2022] [Accepted: 09/26/2022] [Indexed: 11/18/2022]
Abstract
Nicotine, the primary addictive substance in tobacco, produces the psychomotor, rewarding, and reinforcing effects of tobacco dependence by stimulating nicotinic acetylcholine receptors (nAChRs) in the brain. The present study determined that α4β2 nAChRs regulate locomotor sensitization by altering dopamine concentration in the nucleus accumbens (NAc) after systemic challenge exposure to whole cigarette smoke condensate (WCSC). Rats were administered subcutaneous injection of WCSC (0.2 mg/kg nicotine/day) for 7 consecutive days and then re-exposed to WCSC after 3 days of withdrawal. Challenge exposure to WCSC significantly increased locomotor activity. This increase was decreased by the subcutaneous injection of the α4β2 nAChR antagonist, DHβE (3 mg/kg), but not by the intraperitoneal injection of the α7 nAChR antagonist, MLA (5 mg/kg). In parallel with a decrease in locomotor activity, blockade of α4β2 nAChRs with DHβE decreased dopamine concentration in the NAc which was elevated by challenge exposure to WCSC. These findings suggest that challenge WCSC leads to the expression of locomotor sensitization by elevating dopamine concentration via stimulation of α4β2 nAChRs expressed in neurons of the NAc in rats.
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Affiliation(s)
- Ji Sun Kim
- Department of Advanced Toxicology Research, Korea Institute of Toxicology, Daejeon 34114, Republic of Korea
| | - Oc-Hee Kim
- Department of Advanced Toxicology Research, Korea Institute of Toxicology, Daejeon 34114, Republic of Korea
| | - In Soo Ryu
- Department of Advanced Toxicology Research, Korea Institute of Toxicology, Daejeon 34114, Republic of Korea
| | - Yong-Hyun Kim
- Jeonbuk Department of Inhalation Research, Korea Institute of Toxicology, Jeongeup 56212, Republic of Korea; Department of Environment & Energy, Jeonbuk National University, Jeonju, Jeollabukdo 54896, Republic of Korea; School of Civil, Environmental and Resources-Energy Engineering, Jeonbuk National University, Jeonju, Jeollabukdo 54896, Republic of Korea
| | - Kyung Oh Jeon
- Department of Advanced Toxicology Research, Korea Institute of Toxicology, Daejeon 34114, Republic of Korea; Department of Microbiology and Molecular Biology, Chungnam National University, Daejeon 34134, Republic of Korea
| | - Li-Na Lim
- Department of Advanced Toxicology Research, Korea Institute of Toxicology, Daejeon 34114, Republic of Korea
| | - Tae Wan Kim
- Department of Advanced Toxicology Research, Korea Institute of Toxicology, Daejeon 34114, Republic of Korea
| | - Sumin Sohn
- Department of Biological Sciences, Pusan National University, Busan 46241, Republic of Korea
| | - Sunghyun Kim
- Department of Biological Sciences, Pusan National University, Busan 46241, Republic of Korea
| | - Jeong-Wook Seo
- Department of Advanced Toxicology Research, Korea Institute of Toxicology, Daejeon 34114, Republic of Korea
| | - Eun Sang Choe
- Department of Biological Sciences, Pusan National University, Busan 46241, Republic of Korea.
| | - Eun Young Jang
- Department of Advanced Toxicology Research, Korea Institute of Toxicology, Daejeon 34114, Republic of Korea.
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Mahmood HM, Aldhalaan HM, Alshammari TK, Alqasem MA, Alshammari MA, Albekairi NA, AlSharari SD. The Role of Nicotinic Receptors in the Attenuation of Autism-Related Behaviors in a Murine BTBR T + tf/J Autistic Model. Autism Res 2020; 13:1311-1334. [PMID: 32691528 DOI: 10.1002/aur.2342] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2020] [Revised: 04/28/2020] [Accepted: 05/31/2020] [Indexed: 12/15/2022]
Abstract
Nicotinic receptors are distributed throughout the central and peripheral nervous system. Postmortem studies have reported that some nicotinic receptor subtypes are altered in the brains of autistic people. Recent studies have demonstrated the importance of nicotinic acetylcholine receptors (nAChRs) in the autistic behavior of BTBR T + tf/J mouse model of autism. This study was undertaken to examine the behavioral effects of targeted nAChRs using pharmacological ligands, including nicotine and mecamylamine in BTBR T + tf/J and C57BL/6J mice in a panel of behavioral tests relating to autism. These behavioral tests included the three-chamber social interaction, self-grooming, marble burying, locomotor activity, and rotarod test. We examined the effect of various oral doses of nicotine (50, 100, and 400 mcg/mL; po) over a period of 2 weeks in BTBR T + tf/J mouse model. The results indicated that the chronic administration of nicotine modulated sociability and repetitive behavior in BTBR T + tf/J mice while no effects observed in C57BL/6J mice. Furthermore, the nonselective nAChR antagonist, mecamylamine, reversed nicotine effects on sociability and increased repetitive behaviors in BTBR T + tf/J mice. Overall, the findings indicate that the pharmacological modulation of nicotinic receptors is involved in modulating core behavioral phenotypes in the BTBR T + tf/J mouse model. LAY SUMMARY: The involvement of brain nicotinic neurotransmission system plays a crucial role in regulating autism-related behavioral features. In addition, the brain of the autistic-like mouse model has a low acetylcholine level. Here, we report that nicotine, at certain doses, improved sociability and reduced repetitive behaviors in a mouse model of autism, implicating the potential therapeutic values of a pharmacological intervention targeting nicotinic receptors for autism therapy. Autism Res 2020, 13: 1311-1334. © 2020 International Society for Autism Research, Wiley Periodicals, Inc.
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Affiliation(s)
- Hafiz M Mahmood
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Hesham M Aldhalaan
- Department of Neuroscience, Center for Autism Research, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Tahani K Alshammari
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Mashael A Alqasem
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Musaad A Alshammari
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Norah A Albekairi
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Shakir D AlSharari
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia.,Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia, USA
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Ramachandran Nair L, Liu X. Targeting the α4 β2- and α7-Subtypes of Nicotinic Acetylcholine Receptors for Smoking Cessation Medication Development. JOURNAL OF ADDICTION RESEARCH & THERAPY 2019; 10:381. [PMID: 31404286 PMCID: PMC6688641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Nicotine exerts its reinforcing actions via activating the nicotinic acetylcholine receptors (nAChRs). Among an increasing number of nAChR subtypes, the α4β2 and α7 nAChRs are the two major ones, accounting for about 95% of the whole nAChR population in brain. Research findings from our own laboratory, together with other reports in the field, suggest critical and differential involvement of the α4β2 and α7 nAChRs in the process of nicotine dependence and tobacco addiction. Specifically, rat models of nicotine consumption and cue-induced relapse were used to examine the effects of selective antagonism of these two nAChR subtypes on the primary reinforcement of nicotine and the conditioned reinforcing actions of nicotine-associated environmental stimuli (cues). Results demonstrated that blockade of the α4β2 but not α7 subtype effectively reduced nicotine intake, whereas α7 but not α4β2 nAChR blockade reversed cue-triggered nicotine relapse behavior. These findings lend support for the continued effort to develop cholinergic agents aiming at the α4β2 nAChRs for reducing or stopping smoking. However, it is suggested that manipulation of α7 nAChR activity would be a promising target for preventing smoking relapse triggered by exposure to environmental cues.
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Affiliation(s)
| | - Xiu Liu
- Department of Pathology, University of Mississippi Medical Center, Jackson, MS 39216, USA
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6
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Trigo JM, Le Foll B. Nicotine Self-Administration as Paradigm for Medication Discovery for Smoking Cessation: Recent Findings in Medications Targeting the Cholinergic System. Methods Mol Biol 2019; 2011:165-193. [PMID: 31273700 DOI: 10.1007/978-1-4939-9554-7_11] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Tobacco kills every year approximately six million people as a direct result of direct use, and it is still considered one of the most excruciating threats for human health worldwide. The low successful rates of the currently available pharmacotherapies to assist in quitting tobacco use suggest there is a need for more effective treatments.The intravenous self-administration (IVSA) paradigm is considered the gold standard to study voluntary drug intake in animal models, including nicotine. The IVSA paradigm has been used to identify key mechanisms involved in the addictive properties of nicotine in both rodents and nonhuman primates. In this chapter we describe how the IVSA paradigm has served to further investigate the role of nicotinic acetylcholine receptors (nAChRs) in the reinforcing properties of nicotine. Notably, this review will cover recent advances (i.e., research carried out during the past decade) using the IVSA paradigm, with a focus on the status of research on current smoking cessation medications (such as varenicline and bupropion) and of other nAChR ligands.The combination of the IVSA paradigm with pharmacological and genetic tools (e.g., knockout animals) has greatly contributed to our understanding of the role of specific subtype nAChRs in nicotine reinforcement processes. We also discuss some of the limitations of the IVSA paradigm so these can be taken into consideration when interpreting and designing new studies.
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Affiliation(s)
- Jose M Trigo
- Translational Addiction Research Laboratory, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health (CAMH), Toronto, ON, Canada
| | - Bernard Le Foll
- Translational Addiction Research Laboratory, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health (CAMH), Toronto, ON, Canada.
- Addictions Division, CAMH, Toronto, ON, Canada.
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7
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Kozak K, Lucatch AM, Lowe DJE, Balodis IM, MacKillop J, George TP. The neurobiology of impulsivity and substance use disorders: implications for treatment. Ann N Y Acad Sci 2018; 1451:71-91. [PMID: 30291624 DOI: 10.1111/nyas.13977] [Citation(s) in RCA: 94] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 09/11/2018] [Accepted: 09/13/2018] [Indexed: 12/20/2022]
Abstract
Impulsivity is strongly associated with substance use disorders (SUDs). Our review discusses impulsivity as an underlying vulnerability marker for SUDs, and treatment of co-occurring impulsivity in SUDs. Three factors should be considered for the complex relationship between impulsivity and a SUD: (1) the trait effect of impulsivity, centering on decreased cognitive and response inhibition, (2) the state effect resulting from either acute or chronic substance use on brain structure and function, and (3) the genetic and environmental factors (e.g., age and sex) may influence impulsive behavior associated with SUDs. Both subjective and objective measures are used to assess impulsivity. Together, treatment developments (pharmacological, behavioral, and neurophysiological) should consider these clinically relevant dimensions assessed by a variety of measures, which have implications for treatment matching in individuals with SUD. Despite its heterogeneity, impulsivity is a marker associated with SUDs and may be understood as an imbalance of bottom-up and top-down neural systems. Further investigation of these relationships may lead to more effective SUD treatments.
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Affiliation(s)
- Karolina Kozak
- Addictions Division, Centre for Addiction and Mental Health (CAMH), University of Toronto, Toronto, Ontario, Canada.,Division of Brain and Therapeutics, Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada.,Institute of Medical Sciences, University of Toronto, Toronto, Ontario, Canada
| | - Aliya M Lucatch
- Addictions Division, Centre for Addiction and Mental Health (CAMH), University of Toronto, Toronto, Ontario, Canada
| | - Darby J E Lowe
- Addictions Division, Centre for Addiction and Mental Health (CAMH), University of Toronto, Toronto, Ontario, Canada
| | - Iris M Balodis
- Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, Ontario, Canada
| | - James MacKillop
- Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, Ontario, Canada
| | - Tony P George
- Addictions Division, Centre for Addiction and Mental Health (CAMH), University of Toronto, Toronto, Ontario, Canada.,Division of Brain and Therapeutics, Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada.,Institute of Medical Sciences, University of Toronto, Toronto, Ontario, Canada
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8
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Kroemer NB, Veldhuizen MG, Delvy R, Patel BP, O'Malley SS, Small DM. Sweet taste potentiates the reinforcing effects of e-cigarettes. Eur Neuropsychopharmacol 2018; 28:1089-1102. [PMID: 30093174 DOI: 10.1016/j.euroneuro.2018.07.102] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Revised: 07/16/2018] [Accepted: 07/17/2018] [Indexed: 12/20/2022]
Abstract
Electronic cigarettes (e-cigarettes) are becoming increasingly popular. The popularity of fruit flavors among e-cigarette users suggests that sweet taste may contribute to e-cigarette appeal. We therefore tested whether sweet taste potentiates the reinforcing effects of nicotine. Using a conditioning paradigm adapted to study e-cigarettes, we tested whether exposure to flavored e-cigarettes containing nicotine plus sweet taste would be more reinforcing than unsweetened e-cigarettes. Sixteen light cigarette smokers smoked 4 distinctly colored e-cigarettes containing sweetened and unsweetened flavors with or without nicotine for 2 days each. Brain response was then assessed to the sight and smell of the 4 exposed e-cigarettes using fMRI. After exposure, sweet-paired flavors were wanted (p = .024) and tended to be liked (p = .053) more than nicotine-paired flavors. Moreover, sweet taste supra-additively increased liking for nicotine-paired flavors in individuals who did not show increased liking for nicotine alone (r = -.67, p = .005). Accordingly, cues predicting sweet compared to non-sweet flavors elicited a stronger response in the nucleus accumbens (NAcc, pSVC = .050) and the magnitude of response to the sight (pSVC = .022) and smell (pSVC = .017) of the e-cigarettes correlated with changes in liking. By contrast, the sight and smell of cues predicting nicotine alone failed to elicit NAcc response. However, the sight and smell of e-cigarettes paired with sweet+nicotine (pSVC = .035) produced supra-additive NAcc responses. Collectively, these findings demonstrate that sweet taste potentiates the reinforcing effects of nicotine in e-cigarettes resulting in heightened brain cue-reactivity.
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Affiliation(s)
- Nils B Kroemer
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT 06511, USA; The John B. Pierce Laboratory, New Haven, CT 06519, USA; Department of Psychiatry and Psychotherapy, University of Tübingen, 72076 Tübingen, Germany; Department of Psychiatry and Neuroimaging Center, Technische Universität Dresden, 01187 Dresden, Germany.
| | - Maria G Veldhuizen
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT 06511, USA; The John B. Pierce Laboratory, New Haven, CT 06519, USA
| | - Roberta Delvy
- The John B. Pierce Laboratory, New Haven, CT 06519, USA; School of Nursing, Yale University, Orange, CT 06477, USA
| | - Barkha P Patel
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT 06511, USA; The John B. Pierce Laboratory, New Haven, CT 06519, USA; Division of Endocrinology, The Hospital for Sick Children, Toronto, ON M5G 1X8, Canada
| | - Stephanie S O'Malley
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Dana M Small
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT 06511, USA; The John B. Pierce Laboratory, New Haven, CT 06519, USA; Department of Psychology, Yale University, New Haven, CT 06520, USA.
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Cippitelli A, Brunori G, Schoch J, Armishaw CJ, Wu J, Zaveri NT, Giulianotti MA, Welmaker GS, Toll L. Differential regulation of alcohol taking and seeking by antagonism at α4β2 and α3β4 nAChRs. Psychopharmacology (Berl) 2018; 235:1745-1757. [PMID: 29572652 PMCID: PMC5949259 DOI: 10.1007/s00213-018-4883-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Accepted: 03/13/2018] [Indexed: 12/17/2022]
Abstract
RATIONALE Alcoholism is a serious public health problem throughout the world. Current pharmacotherapies for the treatment of this disorder are poorly effective. Preclinical and clinical findings point to nicotinic acetylcholine receptors (nAChRs) as a promising target for the development of novel and effective medications. Assuage Pharmaceuticals, in collaboration with Torrey Pines Institute for Molecular Studies, has discovered a new class of potent and selective α4β2 nAChR antagonists. OBJECTIVE Here, it was hypothesized that α4β2 nAChR antagonism is a viable approach for treatment of alcohol use disorders. RESULTS When tested in rats, one lead compound, AP-202, attenuated both operant alcohol and nicotine self-administration in a paradigm in which the two reinforcers were concurrently available. The conotoxin TP2212-59, a selective α3β4 nAChR antagonist, was only effective in reducing nicotine self-administration. AP-202 also reduced alcohol but not food responding when alcohol was presented as the only reinforcer, whereas the commercially available α4β2 nAChR antagonist dihydro-β-erythroidine failed to alter alcohol self-administration. AP-202 did not block relapse-like behavior induced by previously alcohol-associated stimuli or yohimbine stress. In a reinstatement paradigm, in which alcohol seeking was triggered by a nicotine challenge, a behavior successfully inhibited by the nonselective nAChR antagonist mecamylamine, AP-202 was not effective, while pretreatment with TP2212-59 abolished nicotine-induced reinstatement of alcohol seeking. CONCLUSIONS These findings suggest differential roles for α4β2 and α3β4 nAChR on alcohol taking and seeking with selective blockade of α4β2 nAChR being more implicated in modulating alcohol taking while selective blockade of α3β4 nAChR is involved in nicotine-induced alcohol seeking.
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Affiliation(s)
- Andrea Cippitelli
- Torrey Pines Institute for Molecular Studies, 11350 SW Village Parkway, Port St. Lucie, FL, 34987, USA.
| | - Gloria Brunori
- Torrey Pines Institute for Molecular Studies, 11350 SW Village Parkway, Port St. Lucie, FL 34987, USA
| | - Jennifer Schoch
- Torrey Pines Institute for Molecular Studies, 11350 SW Village Parkway, Port St. Lucie, FL 34987, USA
| | - Christopher J. Armishaw
- Torrey Pines Institute for Molecular Studies, 11350 SW Village Parkway, Port St. Lucie, FL 34987, USA
| | - Jinhua Wu
- Torrey Pines Institute for Molecular Studies, 11350 SW Village Parkway, Port St. Lucie, FL 34987, USA,Assuage Pharmaceuticals, Inc., 11350 SW Village Parkway, Port St. Lucie, FL 34987, USA
| | - Nurulain T. Zaveri
- Astraea Therapeutics, LLC, 320 Logue Avenue, Mountain View, CA 94043, USA
| | - Marc A. Giulianotti
- Torrey Pines Institute for Molecular Studies, 11350 SW Village Parkway, Port St. Lucie, FL 34987, USA,Assuage Pharmaceuticals, Inc., 11350 SW Village Parkway, Port St. Lucie, FL 34987, USA
| | - Gregory S. Welmaker
- Torrey Pines Institute for Molecular Studies, 11350 SW Village Parkway, Port St. Lucie, FL 34987, USA,Assuage Pharmaceuticals, Inc., 11350 SW Village Parkway, Port St. Lucie, FL 34987, USA
| | - Lawrence Toll
- Torrey Pines Institute for Molecular Studies, 11350 SW Village Parkway, Port St. Lucie, FL 34987, USA,Assuage Pharmaceuticals, Inc., 11350 SW Village Parkway, Port St. Lucie, FL 34987, USA
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10
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Kosheleff AR, Araki J, Hsueh J, Le A, Quizon K, Ostlund SB, Maidment NT, Murphy NP. Pattern of access determines influence of junk food diet on cue sensitivity and palatability. Appetite 2018; 123:135-145. [PMID: 29248689 PMCID: PMC5817006 DOI: 10.1016/j.appet.2017.12.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 11/03/2017] [Accepted: 12/07/2017] [Indexed: 12/31/2022]
Abstract
AIMS Like drug addiction, cues associated with palatable foods can trigger food-seeking, even when sated. However, whether susceptibility to the motivating influence of food-related cues is a predisposing factor in overeating or a consequence of poor diet is difficult to determine in humans. Using a rodent model, we explored whether a highly palatable 'junk food' diet impacts responses to reward-paired cues in a Pavlovian-to-instrumental transfer test, using sweetened condensed milk (SCM) as the reward. The hedonic impact of SCM consumption was also assessed by analyzing licking microstructure. METHODS To probe the effects of pattern and duration of junk food exposure, we provided rats with either regular chow ad libitum (controls) or chow plus access to junk food for either 2 or 24 h per day for 1, 3, or 6 weeks. We also examined how individual susceptibility to weight gain related to these measures. RESULTS Rats provided 24 h access to the junk food diet were insensitive to the motivational effects of a SCM-paired cue when tested sated even though their hedonic experience upon reward consumption was similar to controls. In contrast, rats provided restricted, 2 h access to junk food exhibited a cue generalization phenotype under sated conditions, lever-pressing with increased vigor in response to both a SCM-paired cue, and a cue not previously paired with reward. Hedonic response was also significantly higher in these animals relative to controls. CONCLUSIONS These data demonstrate that the pattern of junk food exposure differentially alters the hedonic impact of palatable foods and susceptibility to the motivating influence of cues in the environment to promote food-seeking actions when sated, which may be consequential for understanding overeating and obesity.
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Affiliation(s)
- Alisa R Kosheleff
- Hatos Center for Neuropharmacology, Department of Psychiatry and Biobehavioral Sciences, Semel Institute for Neuroscience and Human Behavior, University of California, 675 Charles E Young Dr. South, MRL #2762, Los Angeles, CA 90095, USA; Department of Psychology, University of California, Los Angeles, CA, USA.
| | - Jingwen Araki
- Hatos Center for Neuropharmacology, Department of Psychiatry and Biobehavioral Sciences, Semel Institute for Neuroscience and Human Behavior, University of California, 675 Charles E Young Dr. South, MRL #2762, Los Angeles, CA 90095, USA
| | - Jennifer Hsueh
- Hatos Center for Neuropharmacology, Department of Psychiatry and Biobehavioral Sciences, Semel Institute for Neuroscience and Human Behavior, University of California, 675 Charles E Young Dr. South, MRL #2762, Los Angeles, CA 90095, USA
| | - Andrew Le
- Hatos Center for Neuropharmacology, Department of Psychiatry and Biobehavioral Sciences, Semel Institute for Neuroscience and Human Behavior, University of California, 675 Charles E Young Dr. South, MRL #2762, Los Angeles, CA 90095, USA
| | - Kevin Quizon
- Hatos Center for Neuropharmacology, Department of Psychiatry and Biobehavioral Sciences, Semel Institute for Neuroscience and Human Behavior, University of California, 675 Charles E Young Dr. South, MRL #2762, Los Angeles, CA 90095, USA
| | - Sean B Ostlund
- Hatos Center for Neuropharmacology, Department of Psychiatry and Biobehavioral Sciences, Semel Institute for Neuroscience and Human Behavior, University of California, 675 Charles E Young Dr. South, MRL #2762, Los Angeles, CA 90095, USA; Department of Anesthesiology and Perioperative Care, University of California, 3111 Gillespie Neuroscience Research Facility 837 Health Sciences Rd, Irvine, CA 92697, USA
| | - Nigel T Maidment
- Hatos Center for Neuropharmacology, Department of Psychiatry and Biobehavioral Sciences, Semel Institute for Neuroscience and Human Behavior, University of California, 675 Charles E Young Dr. South, MRL #2762, Los Angeles, CA 90095, USA
| | - Niall P Murphy
- Hatos Center for Neuropharmacology, Department of Psychiatry and Biobehavioral Sciences, Semel Institute for Neuroscience and Human Behavior, University of California, 675 Charles E Young Dr. South, MRL #2762, Los Angeles, CA 90095, USA
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11
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The α3β4 nAChR partial agonist AT-1001 attenuates stress-induced reinstatement of nicotine seeking in a rat model of relapse and induces minimal withdrawal in dependent rats. Behav Brain Res 2017; 333:251-257. [PMID: 28693859 DOI: 10.1016/j.bbr.2017.07.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Revised: 06/14/2017] [Accepted: 07/06/2017] [Indexed: 11/22/2022]
Abstract
The strong reinforcing effects of nicotine and the negative symptoms such as anxiety experienced during a quit attempt often lead to relapse and low success rates for smoking cessation. Treatments that not only block the reinforcing effects of nicotine but also attenuate the motivation to relapse are needed to improve cessation rates. Recent genetic and preclinical studies have highlighted the involvement of the α3, β4, and α5 nicotinic acetylcholine receptor (nAChR) subunits and the α3β4 nAChR subtype in nicotine dependence and withdrawal. However, the involvement of these nAChR in relapse is not fully understood. We previously reported that the α3β4 nAChR partial agonist AT-1001 selectively decreases nicotine self-administration in rats without affecting food responding. In the present experiments, we examined the efficacy of AT-1001 in attenuating reinstatement of nicotine-seeking behavior in a model of stress-induced relapse. Rats extinguished from nicotine self-administration were treated with the pharmacological stressor yohimbine prior to AT-1001 treatment and reinstatement testing. We also examined whether AT-1001 produced any withdrawal-related effects when administered to nicotine-dependent rats. We found that AT-1001 dose-dependently reduced yohimbine stress-induced reinstatement of nicotine seeking. When administered to nicotine-dependent rats at the dose that significantly blocked nicotine reinstatement, AT-1001 elicited minimal somatic withdrawal signs in comparison to the nicotinic antagonist mecamylamine, which is known to produce robust withdrawal. Our data suggest that α3β4 nAChR-targeted compounds may be a promising approach for nicotine addiction treatment because they can not only block nicotine's reinforcing effects, but also decrease motivation to relapse without producing significant withdrawal effects.
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12
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Chiamulera C, Marzo CM, Balfour DJK. Metabotropic glutamate receptor 5 as a potential target for smoking cessation. Psychopharmacology (Berl) 2017; 234:1357-1370. [PMID: 27847973 DOI: 10.1007/s00213-016-4487-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 11/07/2016] [Indexed: 12/21/2022]
Abstract
RATIONALE Most habitual smokers find it difficult to quit smoking because they are dependent upon the nicotine present in tobacco smoke. Tobacco dependence is commonly treated pharmacologically using nicotine replacement therapy or drugs, such as varenicline, that target the nicotinic receptor. Relapse rates, however, remain high, and there remains a need to develop novel non-nicotinic pharmacotherapies for the dependence that are more effective than existing treatments. OBJECTIVE The purpose of this paper is to review the evidence from preclinical and clinical studies that drugs that antagonise the metabotropic glutamate receptor 5 (mGluR5) in the brain are likely to be efficacious as treatments for tobacco dependence. RESULTS Imaging studies reveal that chronic exposure to tobacco smoke reduces the density of mGluR5s in human brain. Preclinical results demonstrate that negative allosteric modulators (NAMs) at mGluR5 attenuate both nicotine self-administration and the reinstatement of responding evoked by exposure to conditioned cues paired with nicotine delivery. They also attenuate the effects of nicotine on brain dopamine pathways implicated in addiction. CONCLUSIONS Although mGluR5 NAMs attenuate most of the key facets of nicotine dependence, they potentiate the symptoms of nicotine withdrawal. This may limit their value as smoking cessation aids. The NAMs that have been employed most widely in preclinical studies of nicotine dependence have too many "off-target" effects to be used clinically. However, newer mGluR5 NAMs have been developed for clinical use in other indications. Future studies will determine if these agents can also be used effectively and safely to treat tobacco dependence.
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Affiliation(s)
- Cristiano Chiamulera
- Neuropsychopharmacology Lab., Section Pharmacology, Department Diagnostic and Public Health, University of Verona, P.le Scuro 10, 37134, Verona, Italy.
| | - Claudio Marcello Marzo
- Neuropsychopharmacology Lab., Section Pharmacology, Department Diagnostic and Public Health, University of Verona, P.le Scuro 10, 37134, Verona, Italy
| | - David J K Balfour
- Division of Neuroscience, University of Dundee Medical School, Mailbox 6, Ninewells Hospital, Dundee, DD1 9SY, UK
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13
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Bruijnzeel AW. Neuropeptide systems and new treatments for nicotine addiction. Psychopharmacology (Berl) 2017; 234:1419-1437. [PMID: 28028605 PMCID: PMC5420481 DOI: 10.1007/s00213-016-4513-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Accepted: 12/12/2016] [Indexed: 01/08/2023]
Abstract
RATIONALE The mildly euphoric and cognitive enhancing effects of nicotine play a role in the initiation of smoking, while dysphoria and anxiety associated with smoking cessation contribute to relapse. After the acute withdrawal phase, smoking cues, a few cigarettes (i.e., lapse), and stressors can cause relapse. Human and animal studies have shown that neuropeptides play a critical role in nicotine addiction. OBJECTIVES The goal of this paper is to describe the role of neuropeptide systems in the initiation of nicotine intake, nicotine withdrawal, and the reinstatement of extinguished nicotine seeking. RESULTS The reviewed studies indicate that several drugs that target neuropeptide systems diminish the rewarding effects of nicotine by preventing the activation of dopaminergic systems. Other peptide-based drugs diminish the hyperactivity of brain stress systems and diminish withdrawal-associated symptom severity. Blockade of hypocretin-1 and nociceptin receptors and stimulation of galanin and neurotensin receptors diminishes the rewarding effects of nicotine. Both corticotropin-releasing factor type 1 and kappa-opioid receptor antagonists diminish dysphoria and anxiety-like behavior associated with nicotine withdrawal and inhibit stress-induced reinstatement of nicotine seeking. Furthermore, blockade of vasopressin 1b receptors diminishes dysphoria during nicotine withdrawal, and melanocortin 4 receptor blockade prevents stress-induced reinstatement of nicotine seeking. The role of neuropeptide systems in nicotine-primed and cue-induced reinstatement is largely unexplored, but there is evidence for a role of hypocretin-1 receptors in cue-induced reinstatement of nicotine seeking. CONCLUSION Drugs that target neuropeptide systems might decrease the euphoric effects of smoking and improve relapse rates by diminishing withdrawal symptoms and improving stress resilience.
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Affiliation(s)
- Adriaan W. Bruijnzeel
- Department of Psychiatry, University of Florida, Gainesville, Florida, USA,Department of Neuroscience, University of Florida, Gainesville, Florida, USA,Center for Addiction Research and Education, University of Florida, Gainesville, Florida, USA
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14
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Gueye AB, Pryslawsky Y, Trigo JM, Poulia N, Delis F, Antoniou K, Loureiro M, Laviolette SR, Vemuri K, Makriyannis A, Le Foll B. The CB1 Neutral Antagonist AM4113 Retains the Therapeutic Efficacy of the Inverse Agonist Rimonabant for Nicotine Dependence and Weight Loss with Better Psychiatric Tolerability. Int J Neuropsychopharmacol 2016; 19:pyw068. [PMID: 27493155 PMCID: PMC5203757 DOI: 10.1093/ijnp/pyw068] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Accepted: 07/31/2016] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Multiple studies suggest a pivotal role of the endocannabinoid system in regulating the reinforcing effects of various substances of abuse. Rimonabant, a CB1 inverse agonist found to be effective for smoking cessation, was associated with an increased risk of anxiety and depression. Here we evaluated the effects of the CB1 neutral antagonist AM4113 on the abuse-related effects of nicotine and its effects on anxiety and depressive-like behavior in rats. METHODS Rats were trained to self-administer nicotine under a fixed-ratio 5 or progressive-ratio schedules of reinforcement. A control group was trained to self-administer food. The acute/chronic effects of AM4113 pretreatment were evaluated on nicotine taking, motivation for nicotine, and cue-, nicotine priming- and yohimbine-induced reinstatement of nicotine-seeking. The effects of AM4113 in the basal firing and bursting activity of midbrain dopamine neurons were evaluated in a separate group of animals treated with nicotine. Anxiety/depression-like effects of AM4113 and rimonabant were evaluated 24h after chronic (21 days) pretreatment (0, 1, 3, and 10mg/kg, 1/d). RESULTS AM4113 significantly attenuated nicotine taking, motivation for nicotine, as well as cue-, priming- and stress-induced reinstatement of nicotine-seeking behavior. These effects were accompanied by a decrease of the firing and burst rates in the ventral tegmental area dopamine neurons in response to nicotine. On the other hand, AM4113 pretreatment did not have effects on operant responding for food. Importantly, AM4113 did not have effects on anxiety and showed antidepressant-like effects. CONCLUSION Our results indicate that AM4113 could be a promising therapeutic option for the prevention of relapse to nicotine-seeking while lacking anxiety/depression-like side effects.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Bernard Le Foll
- Translational Addiction Research Laboratory (Dr Gueye, Mr Pryslawsky, Dr Trigo, and Dr Le Foll), Alcohol Research and Treatment Clinic, Addiction Medicine Services, Ambulatory Care and Structured Treatments (Dr Le Foll), and Campbell Family Mental Health Research Institute (Dr Le Foll), Centre for Addiction and Mental Health, Toronto, ON, Canada; Department of Family and Community Medicine, Department of Pharmacology, and Department of Psychiatry, Division of Brain and Therapeutics, University of Toronto, Toronto, ON, Canada (Dr Le Foll); Institute of Medical Sciences, University of Toronto, Toronto, ON, Canada (Dr Le Foll); Department of Pharmacology, Faculty of Medicine, School of Health Sciences, University of Ioannina, Greece (Ms Poulia and Drs Delis and Antoniou); Department of Anatomy and Cell Biology, The Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, Canada (Drs Loureiro and Laviolette); Center for Drug Discovery, Department of Pharmaceutical Sciences and Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA (Drs Vemuri and Makriyannis).
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15
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Goodwin AK, Hiranita T, Paule MG. The Reinforcing Effects of Nicotine in Humans and Nonhuman Primates: A Review of Intravenous Self-Administration Evidence and Future Directions for Research. Nicotine Tob Res 2015; 17:1297-310. [PMID: 25673111 DOI: 10.1093/ntr/ntv002] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Accepted: 01/02/2015] [Indexed: 01/21/2023]
Abstract
INTRODUCTION Cigarette smoking is largely driven by the reinforcing properties of nicotine. Intravenous (IV) self-administration procedures are the gold standard for investigating the reinforcing effects of psychoactive drugs. The goal of this review was to examine the results of published investigations of the reinforcing effects of nicotine measured using IV self-administration procedures in humans and nonhuman primates. RESULTS The body of literature using nonhuman primate subjects indicates nicotine functions as a positive reinforcer when available for self-administration via IV catheters. However, it can also be difficult to establish IV nicotine self-administration in nonhuman primates and sometimes supplemental strategies have been required (e.g., priming injections or food deprivation) before subjects acquire the behavior. Although the body of literature using human subjects is limited, the evidence indicates nicotine functions as a reinforcer via the IV route of administration in adult cigarette smokers. Rates of nicotine self-injection can be variable across subjects and responding is sometimes inconsistent across sessions in both humans and nonhuman primates. CONCLUSIONS The Family Smoking Prevention and Tobacco Control Act, enacted in 2009, gave the Food and Drug Administration regulatory authority over the manufacture, marketing, and distribution of tobacco products. Research examining the threshold reinforcing doses for initiation and maintenance of nicotine self-administration, comparisons of the reinforcing effects of nicotine in adolescent versus adult subjects, investigations of gender differences in the reinforcing effects of nicotine, and studies of the abuse liability of non-nicotine tobacco product constituents and their ability to alter the reinforcing effects of nicotine will inform potential tobacco regulatory actions.
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Affiliation(s)
- Amy K Goodwin
- National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR
| | - Takato Hiranita
- National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR
| | - Merle G Paule
- National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR
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Rahman S, Engleman EA, Bell RL. Nicotinic receptor modulation to treat alcohol and drug dependence. Front Neurosci 2015; 8:426. [PMID: 25642160 PMCID: PMC4295535 DOI: 10.3389/fnins.2014.00426] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Accepted: 12/04/2014] [Indexed: 01/10/2023] Open
Abstract
Alcohol and drug dependence are serious public health problems worldwide. The prevalence of alcohol and drug dependence in the United States and other parts of the world is significant. Given the limitations in the efficacy of current pharmacotherapies to treat these disorders, research in developing alternative pharmacotherapies continues. Preclinical and clinical evidence thus far has indicated that brain nicotinic acetylcholine receptors (nAChRs) are important pharmacological targets for the development of medications to treat alcohol and drug dependence. The nAChRs are a super family of ligand gated ion channels, and are expressed throughout the brain with twelve neuronal nAChR subunits (α2–α10 and β2–β4) identified. Here, we review preclinical and clinical evidence involving a number of nAChR ligands that target different nAChR subtypes in alcohol and nicotine addiction. The important ligands include cytisine, lobeline, mecamylamine, varenicline, sazetidine A and others that target α4β2* nAChR subtypes as small molecule modulators of the brain nicotinic cholinergic system are also discussed. Taken together, both preclinical and clinical data exist that support nAChR–based ligands as promising therapeutic agents for the treatment of alcohol and drug dependence.
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Affiliation(s)
- Shafiqur Rahman
- Department of Pharmaceutical Sciences, College of Pharmacy, South Dakota State University Brookings, SD, USA
| | - Eric A Engleman
- Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine Indianapolis, IN, USA
| | - Richard L Bell
- Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine Indianapolis, IN, USA
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17
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Rahman S, Engleman EA, Bell RL. Nicotinic receptor modulation to treat alcohol and drug dependence. Front Neurosci 2015. [DOI: https://doi.org/10.3389/fnins.2014.00426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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18
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Neurobiological Bases of Cue- and Nicotine-induced Reinstatement of Nicotine Seeking: Implications for the Development of Smoking Cessation Medications. Curr Top Behav Neurosci 2015; 24:125-54. [PMID: 25638336 DOI: 10.1007/978-3-319-13482-6_5] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
A better understanding of the neurobiological factors that contribute to relapse to smoking is needed for the development of efficacious smoking cessation medications. Reinstatement procedures allow the preclinical assessment of several factors that contribute to relapse in humans, including re-exposure to nicotine via tobacco smoking and the presentation of stimuli that were previously associated with nicotine administration (i.e., conditioned stimuli). This review provides an integrated discussion of the results of animal studies that used reinstatement procedures to assess the efficacy of pharmacologically targeting various neurotransmitter systems in attenuating the cue- and nicotine-induced reinstatement of nicotine seeking. The results of these animal studies have increased our understanding of the neurobiological processes that mediate the conditioned effects of stimuli that trigger reinstatement to nicotine seeking. Thus, these findings provide important insights into the neurobiological substrates that modulate relapse to tobacco smoking in humans and the ongoing search for novel efficacious smoking cessation medications.
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19
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Rupprecht LE, Smith TT, Schassburger RL, Buffalari DM, Sved AF, Donny EC. Behavioral mechanisms underlying nicotine reinforcement. Curr Top Behav Neurosci 2015; 24:19-53. [PMID: 25638333 PMCID: PMC4536896 DOI: 10.1007/978-3-319-13482-6_2] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Cigarette smoking is the leading cause of preventable deaths worldwide, and nicotine, the primary psychoactive constituent in tobacco, drives sustained use. The behavioral actions of nicotine are complex and extend well beyond the actions of the drug as a primary reinforcer. Stimuli that are consistently paired with nicotine can, through associative learning, take on reinforcing properties as conditioned stimuli. These conditioned stimuli can then impact the rate and probability of behavior and even function as conditioning reinforcers that maintain behavior in the absence of nicotine. Nicotine can also act as a conditioned stimulus (CS), predicting the delivery of other reinforcers, which may allow nicotine to acquire value as a conditioned reinforcer. These associative effects, establishing non-nicotine stimuli as conditioned stimuli with discriminative stimulus and conditioned reinforcing properties as well as establishing nicotine as a CS, are predicted by basic conditioning principles. However, nicotine can also act non-associatively. Nicotine directly enhances the reinforcing efficacy of other reinforcing stimuli in the environment, an effect that does not require a temporal or predictive relationship between nicotine and either the stimulus or the behavior. Hence, the reinforcing actions of nicotine stem both from the primary reinforcing actions of the drug (and the subsequent associative learning effects) as well as the reinforcement enhancement action of nicotine which is non-associative in nature. Gaining a better understanding of how nicotine impacts behavior will allow for maximally effective tobacco control efforts aimed at reducing the harm associated with tobacco use by reducing and/or treating its addictiveness.
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Affiliation(s)
| | | | | | | | - Alan F. Sved
- Department of Neuroscience, University of Pittsburgh
- Department of Psychology, University of Pittsburgh
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20
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Jupp B, Dalley JW. Convergent pharmacological mechanisms in impulsivity and addiction: insights from rodent models. Br J Pharmacol 2014; 171:4729-66. [PMID: 24866553 PMCID: PMC4209940 DOI: 10.1111/bph.12787] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Revised: 05/02/2014] [Accepted: 05/12/2014] [Indexed: 01/15/2023] Open
Abstract
Research over the last two decades has widely demonstrated that impulsivity, in its various forms, is antecedent to the development of drug addiction and an important behavioural trait underlying the inability of addicts to refrain from continued drug use. Impulsivity describes a variety of rapidly and prematurely expressed behaviours that span several domains from impaired response inhibition to an intolerance of delayed rewards, and is a core symptom of attention deficit hyperactivity disorder (ADHD) and other brain disorders. Various theories have been advanced to explain how impulsivity interacts with addiction both causally and as a consequence of chronic drug abuse; these acknowledge the strong overlaps in neural circuitry and mechanisms between impulsivity and addiction and the seemingly paradoxical treatment of ADHD with stimulant drugs with high abuse potential. Recent years have witnessed unprecedented progress in the elucidation of pharmacological mechanisms underpinning impulsivity. Collectively, this work has significantly improved the prospect for new therapies in ADHD as well as our understanding of the neural mechanisms underlying the shift from recreational drug use to addiction. In this review, we consider the extent to which pharmacological interventions that target impulsive behaviour are also effective in animal models of addiction. We highlight several promising examples of convergence based on empirical findings in rodent-based studies.
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Affiliation(s)
- B Jupp
- Behavioural and Clinical Neuroscience Institute and Department of Psychology, University of CambridgeCambridge, UK
- Florey Institute of Neuroscience and Mental Health, University of MelbourneParkville, Australia
| | - J W Dalley
- Behavioural and Clinical Neuroscience Institute and Department of Psychology, University of CambridgeCambridge, UK
- Department of Psychiatry, University of CambridgeCambridge, UK
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Chen H, Luo R, Gong S, Matta SG, Sharp BM. Protection genes in nucleus accumbens shell affect vulnerability to nicotine self-administration across isogenic strains of adolescent rat. PLoS One 2014; 9:e86214. [PMID: 24465966 PMCID: PMC3899218 DOI: 10.1371/journal.pone.0086214] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Accepted: 12/06/2013] [Indexed: 01/20/2023] Open
Abstract
Classical genetic studies show the heritability of cigarette smoking is 0.4–0.6, and that multiple genes confer susceptibility and resistance to smoking. Despite recent advances in identifying genes associated with smoking behaviors, the major source of this heritability and its impact on susceptibility and resistance are largely unknown. Operant self-administration (SA) of intravenous nicotine is an established model for smoking behavior. We recently confirmed that genetic factors exert strong control over nicotine intake in isogenic rat strains. Because the processing of afferent dopaminergic signals by nucleus accumbens shell (AcbS) is critical for acquisition and maintenance of motivated behaviors reinforced by nicotine, we hypothesized that differential basal gene expression in AcbS accounts for much of the strain-to-strain variation in nicotine SA. We therefore sequenced the transcriptome of AcbS samples obtained by laser capture microdissection from 10 isogenic adolescent rat strains and compared all RNA transcript levels with behavior. Weighted gene co-expression network analysis, a systems biology method, found 12 modules (i.e., unique sets of genes that covary across all samples) that correlated (p<0.05) with amount of self-administered nicotine; 9 of 12 correlated negatively, implying a protective role. PCR confirmed selected genes from these modules. Chilibot, a literature mining tool, identified 15 genes within 1 module that were nominally associated with cigarette smoking, thereby providing strong support for the analytical approach. This is the first report demonstrating that nicotine intake by adolescent rodents is associated with the expression of specific genes in AcbS of the mesolimbic system, which controls motivated behaviors. These findings provide new insights into genetic mechanisms that predispose or protect against tobacco addiction.
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Affiliation(s)
- Hao Chen
- Department of Pharmacology, University of Tennessee Health Science Center, Memphis, Tennessee, United States of America
- * E-mail: (HC); (BS)
| | - Rui Luo
- Department of Human Genetics, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | - Suzhen Gong
- Department of Pharmacology, University of Tennessee Health Science Center, Memphis, Tennessee, United States of America
| | - Shannon G. Matta
- Department of Pharmacology, University of Tennessee Health Science Center, Memphis, Tennessee, United States of America
| | - Burt M. Sharp
- Department of Pharmacology, University of Tennessee Health Science Center, Memphis, Tennessee, United States of America
- * E-mail: (HC); (BS)
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Effects of blockade of α4β2 and α7 nicotinic acetylcholine receptors on cue-induced reinstatement of nicotine-seeking behaviour in rats. Int J Neuropsychopharmacol 2014; 17:105-16. [PMID: 23953129 PMCID: PMC3844113 DOI: 10.1017/s1461145713000874] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Exposure to environmental stimuli conditioned to nicotine consumption critically contributes to the high relapse rates of tobacco smoking. Our previous work demonstrated that non-selective blockade of nicotinic acetylcholine receptors (nAChRs) reversed the cue-induced reinstatement of nicotine seeking, indicating a role for cholinergic neurotransmission in the mediation of the conditioned incentive properties of nicotine cues. The present study further examined the relative roles of the two major nAChR subtypes, α4β2 and α7, in the cue-induced reinstatement of nicotine seeking. Male Sprague-Dawley rats were trained to intravenously self-administer nicotine (0.03 mg/kg/infusion, free base) on a fixed-ratio 5 schedule of reinforcement. A nicotine-conditioned cue was established by associating a sensory stimulus with each nicotine infusion. After nicotine-maintained responding was extinguished by withholding the nicotine infusion and its paired cue, reinstatement test sessions were conducted with re-presentation of the cue but without the availability of nicotine. Thirty minutes before the tests, the rats were administered the α4β2-selective antagonist dihydro-β-erythroidine (DHβE) and α7-selective antagonist methyllycaconitine (MLA). Pretreatment with MLA, but not DHβE, significantly reduced the magnitude of the cue-induced reinstatement of responses on the active, previously nicotine-reinforced lever. In different sets of rats, MLA altered neither nicotine self-administration nor cue-induced reinstatement of food seeking. These results demonstrate that activation of α7 nAChRs participates in the mediation of the conditioned incentive properties of nicotine cues and suggest that α7 nAChRs may be a promising target for the development of medications for the prevention of cue-induced smoking relapse.
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Koseki T, Mouri A, Suzuki S, Nakajima A, Mamiya T, Yan Y, Nabeshima T. Galantamine attenuates reinstatement of cue-induced methamphetamine-seeking behavior in mice. Addict Biol 2014; 19:1-4. [PMID: 22260318 DOI: 10.1111/j.1369-1600.2011.00425.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Methamphetamine (METH) dependence is becoming a serious socioeconomic health problem worldwide. The enhancement of the cholinergic nervous system is expected to greatly alleviate drug dependence. We investigated the effect of galantamine on the reinstatement of cue-induced METH-seeking behavior using a self-administration experiment. Treatment with galantamine (1 mg/kg, p.o.) 30 minutes before exposure to the cues suppressed the reinstatement of METH-seeking behavior. However, galantamine did not affect the cue-induced reinstatement of food-seeking behavior or locomotor activity. These results suggest that galantamine may be a candidate drug for treating relapses of METH-seeking behavior.
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Affiliation(s)
- Takenao Koseki
- Department of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, Meijo University, Nagoya, Japan The Academic Frontier Project for Private Universities, Comparative Cognitive Science Institutes, Meijo University, Nagoya, Japan Japanese Drug Organization of Appropriate Use and Research, Nagoya, Japan Department of Neuropsychopharmacology and Hospital Pharmacy, Graduate School of Medicine, Nagoya University, Nagoya, Japan
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Nickell JR, Grinevich VP, Siripurapu KB, Smith AM, Dwoskin LP. Potential therapeutic uses of mecamylamine and its stereoisomers. Pharmacol Biochem Behav 2013; 108:28-43. [PMID: 23603417 PMCID: PMC3690754 DOI: 10.1016/j.pbb.2013.04.005] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2012] [Revised: 04/01/2013] [Accepted: 04/03/2013] [Indexed: 12/17/2022]
Abstract
Mecamylamine (3-methylaminoisocamphane hydrochloride) is a nicotinic parasympathetic ganglionic blocker, originally utilized as a therapeutic agent to treat hypertension. Mecamylamine administration produces several deleterious side effects at therapeutically relevant doses. As such, mecamylamine's use as an antihypertensive agent was phased out, except in severe hypertension. Mecamylamine easily traverses the blood-brain barrier to reach the central nervous system (CNS), where it acts as a nicotinic acetylcholine receptor (nAChR) antagonist, inhibiting all known nAChR subtypes. Since nAChRs play a major role in numerous physiological and pathological processes, it is not surprising that mecamylamine has been evaluated for its potential therapeutic effects in a wide variety of CNS disorders, including addiction. Importantly, mecamylamine produces its therapeutic effects on the CNS at doses 3-fold lower than those used to treat hypertension, which diminishes the probability of peripheral side effects. This review focuses on the pharmacological properties of mecamylamine, the differential effects of its stereoisomers, S(+)- and R(-)-mecamylamine, and the potential for effectiveness in treating CNS disorders, including nicotine and alcohol addiction, mood disorders, cognitive impairment and attention deficit hyperactivity disorder.
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Affiliation(s)
- Justin R Nickell
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, KY 40536, USA.
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Parker CC, Chen H, Flagel SB, Geurts AM, Richards JB, Robinson TE, Solberg Woods LC, Palmer AA. Rats are the smart choice: Rationale for a renewed focus on rats in behavioral genetics. Neuropharmacology 2013; 76 Pt B:250-8. [PMID: 23791960 DOI: 10.1016/j.neuropharm.2013.05.047] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Revised: 05/15/2013] [Accepted: 05/17/2013] [Indexed: 12/13/2022]
Abstract
Due in part to their rich behavioral repertoire rats have been widely used in behavioral studies of drug abuse-related traits for decades. However, the mouse became the model of choice for researchers exploring the genetic underpinnings of addiction after the first mouse study was published demonstrating the capability of engineering the mouse genome through embryonic stem cell technology. The sequencing of the mouse genome and more recent re-sequencing of numerous inbred mouse strains have further cemented the status of mice as the premier mammalian organism for genetic studies. As a result, many of the behavioral paradigms initially developed and optimized for rats have been adapted to mice. However, numerous complex and interesting drug abuse-related behaviors that can be studied in rats are very difficult or impossible to adapt for use in mice, impeding the genetic dissection of those traits. Now, technological advances have removed many of the historical limitations of genetic studies in rats. For instance, the rat genome has been sequenced and many inbred rat strains are now being re-sequenced and outbred rat stocks are being used to fine-map QTLs. In addition, it is now possible to create "knockout" rats using zinc finger nucleases (ZFN), transcription activator-like effector nucleases (TALENs) and related techniques. Thus, rats can now be used to perform quantitative genetic studies of sophisticated behaviors that have been difficult or impossible to study in mice. This article is part of a Special Issue entitled 'NIDA 40th Anniversary Issue'.
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Affiliation(s)
- Clarissa C Parker
- Department of Human Genetics, University of Chicago, Chicago, IL, USA
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26
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Donny EC, Taylor TG, LeSage MG, Levin M, Buffalari DM, Joel D, Sved AF. Impact of tobacco regulation on animal research: new perspectives and opportunities. Nicotine Tob Res 2012; 14:1319-38. [PMID: 22949581 PMCID: PMC3611983 DOI: 10.1093/ntr/nts162] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2012] [Accepted: 05/29/2012] [Indexed: 12/29/2022]
Abstract
INTRODUCTION The Family Smoking Prevention and Tobacco Control Act in the United States and the World Health Organization Framework Convention on Tobacco or Health ratified by over 170 countries render scientific investigations into the abuse liability, harm, and effects of tobacco more critical than ever. A key area to explore relates to the potential regulation of nicotine content in cigarettes. Determining the nicotine content per cigarette below which smokers reliably reduce their consumption of and dependence on cigarettes, an idea proposed almost 20 years ago (Benowitz & Henningfield, 1994), could be a powerful approach to reduce the abuse liability and consequent harm from cigarettes. However, this approach is laden with potentially complex issues. Many of these complications can be studied using animal models, but they require a particular perspective. METHODS Herein, we review several challenges for animal researchers interested in nicotine reduction as examples of how this perspective dictates new approaches to animal research. These include defining the threshold nicotine dose for maintaining self-administration, evaluating the differential impact of various implementation strategies, assessing the factors that could interact with nicotine to alter the reinforcement threshold, describing the role of cues in maintaining low dose nicotine self-administration, and examining individual differences in response to nicotine reduction. CONCLUSIONS Researchers who study tobacco using animal models have the opportunity to play a central role in the regulatory science of tobacco and conduct studies that directly inform policy decisions that could impact the lives of millions.
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Affiliation(s)
- Eric C Donny
- Department of Psychology, Dietrich School of Arts and Sciences, University of Pittsburgh, Pittsburgh, PA, USA.
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27
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Xie X, Arguello AA, Reittinger AM, Wells AM, Fuchs RA. Role of nicotinic acetylcholine receptors in the effects of cocaine-paired contextual stimuli on impulsive decision making in rats. Psychopharmacology (Berl) 2012; 223:271-9. [PMID: 22526542 PMCID: PMC4386831 DOI: 10.1007/s00213-012-2715-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2012] [Accepted: 03/29/2012] [Indexed: 10/28/2022]
Abstract
RATIONALE Chronic cocaine exposure produces unconditioned enhancement in impulsive decision making; however, little is known about the effects of cocaine-paired conditioned stimuli on this behavior. Thus, this study explored the effects of cocaine-paired contextual stimuli on impulsive decision making and the contribution of nicotinic acetylcholine receptors (nAChRs) to this phenomenon. METHODS Rats were trained to achieve stable performance on a delay discounting task, which involved lever press-based choice between a single food pellet (small reward) available immediately and three food pellets (large reward) available after a 10-, 20-, 40-, or 60-s time delay. Rats then received Pavlovian context-cocaine (15 mg/kg, i.p.) and context-saline (1 ml/kg, i.p.) pairings in two other, distinct contexts. Subsequently, delay discounting task performance was assessed in the previously cocaine-paired or saline-paired context following pretreatment with saline or cocaine (15 mg/kg, Experiment 1) or with saline or the nAChR antagonist, mecamylamine (0.2 and 2 mg/kg, Experiment 2), using counterbalanced within-subjects testing designs. RESULTS Independent of cocaine pretreatment, rats exhibited greater decrease in preference for the large reward as a function of delay duration in the cocaine-paired context, relative to the saline-paired context. Furthermore, systemic mecamylamine pretreatment dose-dependently attenuated the decrease in preference for the large reward in the cocaine-paired context, but not in the saline-paired context, as compared to saline. CONCLUSION Cocaine-paired contextual stimuli evoke a state of impulsive decision making, which requires nAChR stimulation. Drug context-induced impulsivity likely increases the propensity for drug relapse in cocaine users, making the nAChR an interesting target for drug relapse prevention.
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Affiliation(s)
| | | | | | | | - Rita A. Fuchs
- Corresponding Author: Rita A. Fuchs, Ph.D., University of North Carolina at Chapel Hill, Department of Psychology, CB# 3270, Davie Hall, Telephone number: (919) 843 – 9112m, FAX number: (919) 962 – 2537,
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Panlilio LV, Justinova Z, Mascia P, Pistis M, Luchicchi A, Lecca S, Barnes C, Redhi GH, Adair J, Heishman SJ, Yasar S, Aliczki M, Haller J, Goldberg SR. Novel use of a lipid-lowering fibrate medication to prevent nicotine reward and relapse: preclinical findings. Neuropsychopharmacology 2012; 37:1838-47. [PMID: 22453137 PMCID: PMC3376316 DOI: 10.1038/npp.2012.31] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Experimental drugs that activate α-type peroxisome proliferator-activated receptors (PPARα) have recently been shown to reduce the rewarding effects of nicotine in animals, but these drugs have not been approved for human use. The fibrates are a class of PPARα-activating medications that are widely prescribed to improve lipid profiles and prevent cardiovascular disease, but these drugs have not been tested in animal models of nicotine reward. Here, we examine the effects of clofibrate, a representative of the fibrate class, on reward-related behavioral, electrophysiological, and neurochemical effects of nicotine in rats and squirrel monkeys. Clofibrate prevented the acquisition of nicotine-taking behavior in naive animals, substantially decreased nicotine taking in experienced animals, and counteracted the relapse-inducing effects of re-exposure to nicotine or nicotine-associated cues after a period of abstinence. In the central nervous system, clofibrate blocked nicotine's effects on neuronal firing in the ventral tegmental area and on dopamine release in the nucleus accumbens shell. All of these results suggest that fibrate medications might promote smoking cessation. The fact that fibrates are already approved for human use could expedite clinical trials and subsequent implementation of fibrates as a treatment for tobacco dependence, especially in smokers with abnormal lipid profiles.
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Affiliation(s)
- Leigh V Panlilio
- Intramural Research Program, Preclinical Pharmacology Section, Department of Health and Human Services, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, USA
| | - Zuzana Justinova
- Intramural Research Program, Preclinical Pharmacology Section, Department of Health and Human Services, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, USA,Department of Psychiatry, Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Paola Mascia
- Intramural Research Program, Preclinical Pharmacology Section, Department of Health and Human Services, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, USA
| | - Marco Pistis
- BB Brodie Department of Neuroscience, University of Cagliari, Cagliari, Italy
| | - Antonio Luchicchi
- BB Brodie Department of Neuroscience, University of Cagliari, Cagliari, Italy
| | - Salvatore Lecca
- BB Brodie Department of Neuroscience, University of Cagliari, Cagliari, Italy
| | - Chanel Barnes
- Intramural Research Program, Preclinical Pharmacology Section, Department of Health and Human Services, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, USA
| | - Godfrey H Redhi
- Intramural Research Program, Preclinical Pharmacology Section, Department of Health and Human Services, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, USA
| | - Jordan Adair
- Intramural Research Program, Preclinical Pharmacology Section, Department of Health and Human Services, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, USA,Department of Psychiatry, Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Stephen J Heishman
- Intramural Research Program, Nicotine Psychopharmacology Section, Department of Health and Human Services, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, USA
| | - Sevil Yasar
- Division of Geriatric Medicine and Gerontology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Mano Aliczki
- Department of Behavioral Neuroscience, Institute of Experimental Medicine, Hungarian Academy of Science, Budapest, Hungary
| | - Jozsef Haller
- Department of Behavioral Neuroscience, Institute of Experimental Medicine, Hungarian Academy of Science, Budapest, Hungary
| | - Steven R Goldberg
- Intramural Research Program, Preclinical Pharmacology Section, Department of Health and Human Services, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, USA,National Institute on Drug Abuse, Biomedical Research Center, 251 Bayview Boulevard, Baltimore, MD 21224, USA, Tel: +1 443 740 2519; Fax: +1 443 740 2733; E-mail:
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Domino EF, Ni L, Domino JS, Yang W, Evans C, Guthrie S, Wang H, Koeppe RA, Zubieta JK. Denicotinized versus average nicotine tobacco cigarette smoking differentially releases striatal dopamine. Nicotine Tob Res 2012; 15:11-21. [PMID: 22491891 DOI: 10.1093/ntr/nts029] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
INTRODUCTION Nicotine has long been recognized as a necessary but insufficient component of tobacco cigarettes to maintain a psychophysiological need to smoke. This study examined venous plasma concentrations effects of nicotine in cigarette smoking after overnight abstinence to release striatal dopamine (DA). METHODS Twenty-two male smokers smoked either denicotinized (denic) or average nicotine (nic) cigarettes under single blind conditions. Each was given [(11)C]raclopride and scanned in a positron emission tomography (PET) facility. RESULTS Smoking either denic or nic cigarettes released striatal DA. Denic cigarette smoking released DA primarily in the right striatum, whereas nic cigarette smoking released DA in both striata, but especially in the left. Increases in venous plasma nicotine concentrations correlated positively with increased DA release in the left caudate nucleus. Smoking denic cigarettes reduced craving as much as smoking nic cigarettes. Craving reduction after nic tobacco smoking correlated with increases in plasma nicotine. CONCLUSIONS Nonnicotine factors in tobacco smoking produce important right brain effects. Nicotine is a pharmacological factor during tobacco smoking that releases bilateral striatal DA, but more in the left brain.
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Affiliation(s)
- Edward F Domino
- Department of Pharmacology, University of Michigan, Ann Arbor, MI 48109-5632, USA.
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Vasic N, Wolf RC, Wolf N, Connemann BJ, Sosic-Vasic Z. [Pharmacotherapeutic treatment strategies for smoking cessation]. DER NERVENARZT 2011; 82:1449-1459. [PMID: 21207000 DOI: 10.1007/s00115-010-3203-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Regular tobacco smoking occurs in about 35% of the male and 25% of the female German population. Individual attempts to independently quit smoking and to remain abstinent for 1 year have been shown to be successful in less than 5% of cases. This rate can be doubled by means of individual consulting and cognitive-behavioral interventions and additional pharmacological treatment might increase abstinence rates up to 25%. Apart from nicotine substitution (e.g. transdermal, oral and inhalative applications) and bupropion, recent studies have shown beneficial effects of varenicline for smoking cessation and abstinence. Varenicline, a selective partial nicotinergic agonist, has been specifically developed for the purpose of smoking cessation. Currently available data suggest that varenicline is more effective compared to nicotine substitution therapy and bupropion, increasing the abstinence likelihood by a factor of 2.3 compared to a placebo. Recent data regarding anti-nicotine vaccines suggest that this approach might yield a comparable treatment outcome and probably even better relapse-preventing effects than conventional psychopharmacological strategies. The first anti-nicotine vaccines are expected to be approved by national authorities within the forthcoming 1-2 years.
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Affiliation(s)
- N Vasic
- Klinik für Psychiatrie und Psychotherapie III, Universitätsklinikum, Ulm, Deutschland.
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31
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Paterson NE, Min W, Hackett A, Lowe D, Hanania T, Caldarone B, Ghavami A. The high-affinity nAChR partial agonists varenicline and sazetidine-A exhibit reinforcing properties in rats. Prog Neuropsychopharmacol Biol Psychiatry 2010; 34:1455-64. [PMID: 20708056 DOI: 10.1016/j.pnpbp.2010.07.037] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2010] [Revised: 07/23/2010] [Accepted: 07/31/2010] [Indexed: 11/29/2022]
Abstract
Varenicline (Chantix®, Champix®) is a nicotinic acetylcholine receptor (nAChR) partial agonist clinically approved for smoking cessation, yet its potential abuse liability properties have not been fully characterized. The nAChR ligand sazetidine-A has been reported as a selective full or partial agonist at α4β2* nAChR subtypes in in vitro studies. In the present studies, varenicline, sazetidine-A and nicotine exhibited inverted U-shaped dose-response functions under fixed-ratio (peak responding at 30, 60 and 10-30 μg/kg/inf, respectively) or progressive-ratio (peak responding at 30-60, 30-100 and 30 μg/kg/inf, respectively) schedules in rats trained to self-administer nicotine. Varenicline (ED(50) 0.2 mg/kg) and sazetidine-A (ED(50) 0.44 mg/kg) fully substituted for nicotine (ED(50) 0.09 mg/kg) in rats trained to discriminate nicotine (0.4 mg/kg, i.p.) from saline. The reinforcing and discriminative stimulus (DS) properties of sazetidine-A, varenicline and nicotine were attenuated by acute pretreatment with the non-selective neuronal non-competitive nAChR antagonist mecamylamine or the α4* nAChR-selective antagonist dihydro-β-erythroidine, but not by the α7 nAChR subtype antagonist methyllycaconitine. Drug-naïve rats acquired stable self-administration of varenicline (30 μg/kg/inf), and sazetidine-A (60 μg/kg/inf), at doses that supported peak responding under a fixed-ratio 3 schedule in nicotine-trained rats. Nonetheless, self-administration and re-acquisition of varenicline and sazetidine-A were less robust than nicotine. Thus, partial activation of α4β2* nAChRs by varenicline or sazetidine-A is sufficient to mimic the DS and reinforcing properties of nicotine in nicotine-experienced rats, although the reinforcing properties of partial agonists are diminished in nicotine-naïve rats. Future studies should assess nicotine withdrawal measures in animals chronically exposed to varenicline or sazetidine-A.
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Affiliation(s)
- Neil E Paterson
- PsychoGenics, Inc., 765 Old Saw Mill River Rd., Tarrytown, NY 10591, United States.
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32
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Jones J, Raiff BR, Dallery J. Nicotine's enhancing effects on responding maintained by conditioned reinforcers are reduced by pretreatment with mecamylamine, but not hexamethonium, in rats. Exp Clin Psychopharmacol 2010; 18:350-8. [PMID: 20695691 PMCID: PMC3626497 DOI: 10.1037/a0020601] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Several studies have indicated that nicotine increases responding maintained by conditioned reinforcers. We assessed the effects of subcutaneous injections of 0.3 mg/kg nicotine and two nicotinic antagonists on responding maintained by conditioned and primary reinforcers and responding during extinction in 8 Long Evans rats. Mecamylamine, a central and peripheral nicotinic antagonist, and hexamethonium, a peripheral nicotinic antagonist, were administered prior to a subset of the experimental sessions. Nicotine selectively increased responding maintained by conditioned reinforcers and mecamylamine, but not hexamethonium, attenuated this effect. These results suggest that nicotine's enhancing effect on responding maintained by conditioned reinforcers is mediated in the central nervous system.
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Affiliation(s)
| | - Bethany R. Raiff
- University of Florida,National Development and Research Institutes
| | - Jesse Dallery
- University of Florida,National Development and Research Institutes
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Forget B, Pushparaj A, Le Foll B. Granular insular cortex inactivation as a novel therapeutic strategy for nicotine addiction. Biol Psychiatry 2010; 68:265-71. [PMID: 20299008 DOI: 10.1016/j.biopsych.2010.01.029] [Citation(s) in RCA: 123] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2009] [Revised: 01/28/2010] [Accepted: 01/29/2010] [Indexed: 10/19/2022]
Abstract
BACKGROUND Nicotine is the principal component of tobacco smoke, resulting in addiction, and recent evidence suggests that damage to the insular cortex (insula) disrupts tobacco addiction in human smokers. However, the effect of an inactivation of this structure in an animal model of nicotine addiction has yet to be evaluated. METHODS To study this question, we investigated the effects of reversible inactivation of the granular insula by local injection of a gamma-aminobutyric acid agonists mixture (baclofen/muscimol) on nicotine self-administration (SA) under fixed and progressive ratio and on reinstatement of nicotine seeking induced by nicotine priming or nicotine-associated cues in rats. We also evaluated the effects of granular insula inactivation on food SA and relapse as a control. RESULTS The inactivation of the granular insula decreased nicotine SA under both fixed and progressive ratios without affecting the SA of food under the same schedules of reinforcement. This inactivation also prevented the reinstatement, after extinction, of nicotine seeking induced by nicotine-associated cues or nicotine priming without modifying the reinstatement of food seeking. CONCLUSIONS Our study indicates that the integrity of the granular insula is necessary for exhibiting motivation to take nicotine and to relapse to nicotine seeking but not for consuming food pellets or to relapse for food seeking. Indeed, it might be interesting to study the effect of methods that are able to modulate the activity of the insula--such as repetitive transcranial magnetic stimulation or deep brain stimulation--on tobacco addiction and relapse in humans.
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Affiliation(s)
- Benoit Forget
- Translational Addiction Research Laboratory, Pharmacology and Psychiatry, Institutes of Medical Sciences, University of Toronto, Toronto, Canada
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Clemens KJ, Caillé S, Cador M. The effects of response operandum and prior food training on intravenous nicotine self-administration in rats. Psychopharmacology (Berl) 2010; 211:43-54. [PMID: 20437028 DOI: 10.1007/s00213-010-1866-z] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2010] [Accepted: 04/10/2010] [Indexed: 10/19/2022]
Abstract
RATIONALE Nicotine intravenous self-administration (IVSA) in rats has been conducted using a variety of methodological procedures with equally variable results. OBJECTIVES Here, we addressed the importance of the type of response operandum and prior instrumental training with a natural reinforcer on nicotine IVSA and reinstatement. METHODS Rats were tested for spontaneous acquisition of IVSA using either nose poke (NP) or lever press (LVR) operandum. A dose-response test was then conducted, followed by extinction and cue- and nicotine-induced reinstatement. RESULTS The use of the NP operandum resulted in markedly higher levels of IVSA across acquisition and across dose-response testing compared with the LVR group. Whereas both groups reinstated following a nicotine prime, only the LVR group demonstrated cue-induced reinstatement. As a positive control, the experiment was repeated with cocaine as the reinforcer: equivalent levels of IVSA were observed across all tests, irrespective of operandum. When rats self-administering nicotine received instrumental training with a sucrose reinforcer prior to IVSA, a facilitated acquisition of IVSA was observed in both LVR and NP groups to a similar extent (the effect of operandum remained), but had little effect on responding thereafter. During reinstatement testing, both groups now displayed cue- and nicotine-induced reinstatement, but this was also evident in saline control animals that had never received nicotine. CONCLUSIONS These results suggest that, unlike cocaine, an increased physical response requirement can decrease nicotine intake. It also indicates that operandum and prior sucrose training may influence the role that visual cues play in nicotine dependence.
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Affiliation(s)
- Kelly J Clemens
- CNRS UMR 5227, Team "Neuropsychopharmacology of Addiction", University of Bordeaux 2, Bordeaux, France.
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Effects of dopamine antagonists on drug cue-induced reinstatement of nicotine-seeking behavior in rats. Behav Pharmacol 2010; 21:153-60. [PMID: 20168211 DOI: 10.1097/fbp.0b013e328337be95] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Dopaminergic neurotransmission has been implicated in associative learning processes related to drugs of abuse. However, it is not clear whether blockade of activation of dopamine receptors alters conditioned incentive properties of nicotine-associated cues. Using a response-reinstatement procedure, this study examined the effects of antagonists selective for the D1 and the D2 subtypes of dopamine receptors on cue-induced reinstatement of nicotine-seeking behavior. Male Sprague-Dawley rats were trained in 30 daily 1 h sessions to intravenously self-administer nicotine (0.03 mg/kg/infusion) on a fixed ratio 5 schedule and associate a conditioned stimulus (cue) with each nicotine delivery. After extinction of responding by withholding nicotine (saline substitution) and its cue, the reinstatement tests were conducted following subcutaneous administration of a D1 antagonist SCH23390 (0, 5, 10, 30 microg/kg) or a D2 antagonist eticlopride (0, 5, 10, 30 microg/kg) in different groups of animals. Both SCH23390 and eticlopride significantly attenuated the magnitude of cue-elicited reinstatement of nicotine-seeking responding. These results indicate that activation of dopaminergic D1 and D2 receptors may play a role in mediating the conditioned motivational effects of nicotine-associated cues as measured in the response-reinstatement procedure. These findings suggest that manipulation of dopaminergic neurotransmission at D1 and/or D2 receptors may prove to be a potential target for the development of pharmacotherapy for prevention of environmental nicotine cue-triggered smoking relapse.
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36
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Biala G, Staniak N. Varenicline and mecamylamine attenuate locomotor sensitization and cross-sensitization induced by nicotine and morphine in mice. Pharmacol Biochem Behav 2010; 96:141-7. [PMID: 20451547 DOI: 10.1016/j.pbb.2010.04.022] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2009] [Revised: 04/19/2010] [Accepted: 04/28/2010] [Indexed: 11/29/2022]
Abstract
The present study focused on the evaluation of behavioural sensitization and cross-sensitization induced by nicotine and morphine in mice. First, we revealed that after 9days of nicotine administration (0.175mg/kg, free base), every other day and following its 7-day withdrawal, challenge doses of nicotine (0.175mg/kg) and morphine (5mg/kg) induced locomotor sensitization in mice. When we examined the influence of varenicline, a partial alpha4beta2 nicotinic receptor agonist (0.5, 1 and 2mg/kg) and mecamylamine (0.5, 1 and 2mg/kg), a non-selective nicotinic receptor antagonist, we found that both agents attenuated the acquisition and expression of nicotine sensitization as well as locomotor cross-sensitization between nicotine and morphine. Our results indicate similar cholinergic mechanisms involved in the locomotor stimulant effects of nicotine and morphine in mice, and as such these data may suggest that nicotinic neurotransmission could be a potential target for developing pharmacotherapeutic strategies to treat and prevent nicotine and/or opioid addiction.
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Affiliation(s)
- Grazyna Biala
- Department of Pharmacology and Pharmacodynamics, Medical University of Lublin, 4 Staszica Street, 20-081 Lublin, Poland.
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O'Connor EC, Parker D, Rollema H, Mead AN. The alpha4beta2 nicotinic acetylcholine-receptor partial agonist varenicline inhibits both nicotine self-administration following repeated dosing and reinstatement of nicotine seeking in rats. Psychopharmacology (Berl) 2010; 208:365-76. [PMID: 19967529 DOI: 10.1007/s00213-009-1739-5] [Citation(s) in RCA: 104] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2008] [Accepted: 11/16/2009] [Indexed: 10/20/2022]
Abstract
INTRODUCTION The alpha4beta2 nicotinic acetylcholine receptor partial agonist varenicline has greater efficacy than other pharmacotherapeutic aids for smoking cessation. This presents an opportunity to evaluate the predictive validity of rat models of nicotine taking and relapse. The aim of this study was to evaluate the ability of varenicline to attenuate nicotine self-administration and relapse, as modelled by the reinstatement model of nicotine relapse in rats. MATERIALS AND METHODS Rats were trained to respond for intravenous nicotine under a fixed ratio schedule of reinforcement. The effects of varenicline (0.3-3.0 mg/kg s.c.) on both nicotine and food self-administration and reinstatement of nicotine seeking were evaluated. RESULTS AND DISCUSSION Varenicline dose-dependently reduced nicotine self-administration and attenuated both nicotine prime and combined nicotine prime plus nicotine-paired cue-induced reinstatement. Varenicline had no effect on cue-induced reinstatement in the absence of a nicotine prime nor did it induce reinstatement when given alone. CONCLUSION The effects of varenicline on nicotine-induced reinstatement of drug-seeking are consistent with the demonstrated clinical efficacy of varenicline for smoking cessation.
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Affiliation(s)
- Eoin C O'Connor
- School of Psychology, University of Sussex, Falmer, Brighton BN19QG, UK
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Dwoskin LP, Smith AM, Wooters TE, Zhang Z, Crooks PA, Bardo MT. Nicotinic receptor-based therapeutics and candidates for smoking cessation. Biochem Pharmacol 2009; 78:732-43. [PMID: 19523455 PMCID: PMC4110684 DOI: 10.1016/j.bcp.2009.06.002] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2009] [Revised: 05/29/2009] [Accepted: 06/01/2009] [Indexed: 12/29/2022]
Abstract
Tobacco dependence is the most preventable cause of death and is a chronic, relapsing disorder in which compulsive tobacco use persists despite known negative health consequences. All currently available cessation agents (nicotine, varenicline and bupropion) have limited efficacy and are associated with high relapse rates, revealing a need for more efficacious, alternative pharmacotherapies. The major alkaloid in tobacco, nicotine, activates nicotinic receptors (nAChRs) which increase brain extracellular dopamine producing nicotine reward leading to addiction. nAChRs are located primarily presynaptically and modulate synaptic activity by regulating neurotransmitter release. Subtype-selective nAChR antagonists that block reward-relevant mesocorticolimbic and nigrostriatal dopamine release induced by nicotine may offer advantages over current therapies. An innovative approach is to provide pharmacotherapies which are antagonists at nAChR subtypes mediating nicotine evoked dopamine release. In addition, providing multiple medications with a wider array of targets and mechanisms should provide more treatment options for individuals who are not responsive to the currently available pharmacotherapies. This review summarizes the currently available smoking cessation therapies and discusses emerging potential therapeutic approaches employing pharmacological agents which act as antagonists at nicotinic receptors.
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Affiliation(s)
- Linda P Dwoskin
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, KY 40536, USA.
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39
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Affiliation(s)
- Mohammed Shoaib
- Psychobiology Research Laboratories, Institute of Neuroscience, Medical School, Newcastle University, Newcastle Upon Tyne, UK.
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Forget B, Coen KM, Le Foll B. Inhibition of fatty acid amide hydrolase reduces reinstatement of nicotine seeking but not break point for nicotine self-administration--comparison with CB(1) receptor blockade. Psychopharmacology (Berl) 2009; 205:613-24. [PMID: 19484221 DOI: 10.1007/s00213-009-1569-5] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2008] [Accepted: 05/05/2009] [Indexed: 12/26/2022]
Abstract
RATIONALE The endocannabinoid system has been recently identified as having critical involvement in drug taking and relapse phenomenon for various drugs of abuse and notably nicotine. The endocannabinoid system consists of endocannabinoids (such as anandamide), their target receptors (mostly cannabinoid CB(1) receptors), and the enzymes that degrade those endocannabinoids (fatty-acid-amide-hydrolase (FAAH) for anandamide). It has been recently identified that the utility of rimonabant for smoking cessation may be limited by its psychiatric side effects. Therefore, there is a great need to develop alternative ways of modulating the cannabinoid system that will be better tolerated. OBJECTIVE The aim of the study was to explore the effect of inhibiting FAAH enzyme by URB597 on nicotine self-administration under a progressive ratio schedule and reinstatement of nicotine seeking, in comparison with the effect of the CB(1) antagonist rimonabant. RESULTS Rimonabant, but not URB597, dose-dependently reduced the break point for nicotine self-administration, an effect that was stable over repeated administrations. Rimonabant and URB597 significantly decreased the reinstatement of nicotine seeking induced either by presentation of nicotine-associated stimuli or by nicotine priming. CONCLUSIONS These results indicate that the integrity of the CB(1) receptors is necessary for the incentive motivation of the rats for nicotine and that FAAH inhibition may be as effective as CB(1) receptor blockade to prevent reinstatement of nicotine seeking. Since FAAH inhibition present antidepressant and anxiolytic properties in rodents, targeting the FAAH may represent a novel strategy to prevent relapse for tobacco smoking that may be better tolerated than rimonabant.
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Affiliation(s)
- Benoit Forget
- Translational Addiction Research Laboratory, Centre for Addiction and Mental Health (CAMH), Toronto, Canada, M5S 2S1
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Nair SG, Adams-Deutsch T, Epstein DH, Shaham Y. The neuropharmacology of relapse to food seeking: methodology, main findings, and comparison with relapse to drug seeking. Prog Neurobiol 2009; 89:18-45. [PMID: 19497349 PMCID: PMC2745723 DOI: 10.1016/j.pneurobio.2009.05.003] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2009] [Revised: 04/09/2009] [Accepted: 05/26/2009] [Indexed: 12/15/2022]
Abstract
Relapse to old, unhealthy eating habits is a major problem in human dietary treatments. The mechanisms underlying this relapse are unknown. Surprisingly, until recently this clinical problem has not been systematically studied in animal models. Here, we review results from recent studies in which a reinstatement model (commonly used to study relapse to abused drugs) was employed to characterize the effect of pharmacological agents on relapse to food seeking induced by either food priming (non-contingent exposure to small amounts of food), cues previously associated with food, or injections of the pharmacological stressor yohimbine. We also address methodological issues related to the use of the reinstatement model to study relapse to food seeking, similarities and differences in mechanisms underlying reinstatement of food seeking versus drug seeking, and the degree to which the reinstatement procedure provides a suitable model for studying relapse in humans. We conclude by discussing implications for medication development and future research. We offer three tentative conclusions: (1)The neuronal mechanisms of food-priming- and cue-induced reinstatement are likely different from those of reinstatement induced by the pharmacological stressor yohimbine. (2)The neuronal mechanisms of reinstatement of food seeking are possibly different from those of ongoing food-reinforced operant responding. (3)The neuronal mechanisms underlying reinstatement of food seeking overlap to some degree with those of reinstatement of drug seeking.
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Affiliation(s)
- Sunila G. Nair
- Behavioral Neuroscience Branch, NIDA/IRP, 251 Bayview Boulevard, Baltimore, MD, 21224
| | - Tristan Adams-Deutsch
- Behavioral Neuroscience Branch, NIDA/IRP, 251 Bayview Boulevard, Baltimore, MD, 21224
| | - David H. Epstein
- Clinical Pharmacology and Therapeutics Research Branch, NIDA/IRP, 251 Bayview Boulevard, Baltimore, MD, 21224
| | - Yavin Shaham
- Behavioral Neuroscience Branch, NIDA/IRP, 251 Bayview Boulevard, Baltimore, MD, 21224
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Coolon RA, Cain ME. Effects of mecamylamine on nicotine-induced conditioned hyperactivity and sensitization in differentially reared rats. Pharmacol Biochem Behav 2009; 93:59-66. [PMID: 19379770 DOI: 10.1016/j.pbb.2009.04.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2008] [Revised: 04/12/2009] [Accepted: 04/13/2009] [Indexed: 10/20/2022]
Abstract
Rats reared in an enriched condition (EC) display less sensitization to nicotine than rats reared in an impoverished condition (IC). However, it is unknown what effect differential rearing has on nicotine-induced conditioned hyperactivity. The present study determined whether differential rearing affects nicotine-induced conditioned hyperactivity. This study also examined the effects of mecamylamine on conditioned hyperactivity and sensitization. EC, IC, and social condition (SC) rats were reared from 21 to 51 days of age before receiving repeated nicotine injections (.4 mg/kg) prior to 1-h locomotor sessions. Following the conditioned-hyperactivity test, rats received additional training sessions followed by a drug-free rest period before the sensitization test. Mecamylamine (1.0 mg/kg) was administered prior to the conditioned-hyperactivity test and sensitization test. Nicotine treatment resulted in sensitization and conditioned hyperactivity in all differential rearing groups. EC rats displayed less locomotor activity in response to nicotine than both IC and SC rats. Pretreatment with mecamylamine blocked the expression of conditioned hyperactivity only in EC and SC rats and attenuated sensitization in all three rearing groups. These findings suggest that environmental enrichment may alter nicotinic acetylcholine receptors during development and may be a protective factor in the initiation and relapse of smoking behavior.
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Affiliation(s)
- Rosemary A Coolon
- Kansas State University, Department of Psychology, 418 Bluemont Hall, 1100 Mid-Campus Drive, Manhattan, KS 66506-5302, USA
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Liu X, Palmatier MI, Caggiula AR, Sved AF, Donny EC, Gharib M, Booth S. Naltrexone attenuation of conditioned but not primary reinforcement of nicotine in rats. Psychopharmacology (Berl) 2009; 202:589-98. [PMID: 18807246 PMCID: PMC2811405 DOI: 10.1007/s00213-008-1335-0] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2007] [Accepted: 09/04/2008] [Indexed: 12/01/2022]
Abstract
RATIONALE Opioid neurotransmission has been implicated in reinforcement-related processes for several drugs of abuse, including opiates, stimulants, and alcohol. However, less is known about its role in the motivational effects of nicotine and nicotine-associated environmental cues. OBJECTIVE This study investigated whether pretreatment with naltrexone, an opioid receptor antagonist, alters conditioned incentive salience of nicotine cues under two conditions: cue-induced reinstatement of nicotine-seeking after extinction and cue-maintained responding during extinction. The effect of naltrexone on nicotine self-administration during the maintenance phase was also examined. MATERIALS AND METHODS Male Sprague-Dawley rats were trained in daily 1-h sessions to self-administer nicotine (0.03 mg/kg/infusion, i.v.) on a fixed-ratio 5 schedule and associate a conditioned stimulus (CS) with each nicotine delivery. Once responding was extinguished by saline substitution for nicotine and omission of the CS, the reinstatement tests were conducted following subcutaneous administration of naltrexone (0, 0.25, 1, 2 mg/kg). In separate groups of rats, naltrexone (0, 2 mg/kg) was chronically given before each extinction sessions, where responses on the active lever resulted in presentations of the CS without nicotine infusion (saline substitution). Self-administration/naltrexone tests were conducted in different groups of rats receiving similar nicotine self-administration training. RESULTS Naltrexone significantly attenuated the CS-reinstated responding on the active, previously nicotine-reinforced lever in the reinstatement tests and the CS-maintained active lever responding during the extinction tests. In contrast, neither acute nor chronic naltrexone produced an effect on nicotine self-administration behavior. CONCLUSIONS These results indicate that activation of opioid receptors is implicated in mediation of the conditioned incentive properties of nicotine cues but not in the maintenance of nicotine self-administration. Therefore, these findings suggest that opioid receptor antagonists might have clinical potential for prevention of smoking relapse associated with exposure to environmental cues.
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Affiliation(s)
- Xiu Liu
- Division of Neurobiology and Behavior Research, Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, 2500 N. State St., Jackson, MS 39216, USA.
| | | | - Anthony R. Caggiula
- Department of Psychology, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Alan F. Sved
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Eric C. Donny
- Department of Psychology, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Maysa Gharib
- Department of Psychology, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Sheri Booth
- Department of Psychology, University of Pittsburgh, Pittsburgh, PA 15260, USA
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Gass JT, Osborne MP, Watson NL, Brown JL, Olive MF. mGluR5 antagonism attenuates methamphetamine reinforcement and prevents reinstatement of methamphetamine-seeking behavior in rats. Neuropsychopharmacology 2009; 34:820-33. [PMID: 18800068 PMCID: PMC2669746 DOI: 10.1038/npp.2008.140] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Addiction to methamphetamine is a significant public health problem, and there are currently no pharmacological agents that are approved for the treatment of addiction to this powerful psychostimulant. Chronic methamphetamine use leads to cognitive dysfunction as well as numerous psychiatric, neurological, and cardiovascular complications. There is a growing body of literature implicating an important role for glutamate neurotransmission in psychostimulant addiction. In the present study, we examined the effects of the selective type 5 metabotropic glutamate receptor (mGluR5) antagonist 3-((2-methyl-1,3-thiazol-4-yl)ethynyl)pyridine (MTEP) on intravenous self-administration of methamphetamine and reinstatement of methamphetamine-seeking behavior. Adult male Sprague-Dawley rats were trained to respond for intravenous methamphetamine (0.1 or 0.2 mg/kg per infusion) or food pellets and were subsequently administered vehicle or MTEP (0.3-3 mg/kg) before drug or food self-administration on a fixed-ratio 1 (FR1) schedule of reinforcement or a progressive ratio (PR) schedule of reinforcement. We also examined the effects of vehicle or MTEP (0.3-3 mg/kg) on cue- and drug-induced reinstatement of methamphetamine-seeking behavior as well as cue-induced reinstatement of food-seeking behavior. Our results show that MTEP dose dependently reduced the reinforcing effects of methamphetamine under FR1 and PR schedules of reinforcement without altering overall responding for food. MTEP also dose dependently prevented cue- and drug-induced reinstatement of methamphetamine-seeking behavior, but did not alter cue-induced reinstatement of food-seeking behavior. Together, these results indicate that mGluR5 receptors mediate methamphetamine reinforcement and methamphetamine-seeking behavior, and that pharmacological inhibitors of mGluR5 receptor function may represent a novel class of potential therapeutic agents for the treatment of methamphetamine addiction.
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Affiliation(s)
- Justin T. Gass
- Center for Drug and Alcohol Programs, Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, SC, USA
| | - Megan P.H. Osborne
- Center for Drug and Alcohol Programs, Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, SC, USA
| | - Noreen L. Watson
- Center for Drug and Alcohol Programs, Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, SC, USA
| | - Jordan L. Brown
- Center for Drug and Alcohol Programs, Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, SC, USA
| | - M. Foster Olive
- Center for Drug and Alcohol Programs, Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, SC, USA
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Le Foll B, Goldberg SR. Effects of nicotine in experimental animals and humans: an update on addictive properties. Handb Exp Pharmacol 2009:335-67. [PMID: 19184655 PMCID: PMC2687081 DOI: 10.1007/978-3-540-69248-5_12] [Citation(s) in RCA: 115] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Tobacco use through cigarette smoking is the leading preventable cause of death in the developed world. Nicotine, a psychoactive component of tobacco, appears to play a major role in tobacco dependence, but the reinforcing effects of nicotine have often been difficult to demonstrate directly in controlled studies with laboratory animals or human subjects. Here we update our earlier review published in Psychopharmacology (Berl) in 2006 on findings obtained with various procedures developed to study dependence-related behavioral effects of nicotine in experimental animals and humans. Results obtained with drug self-administration, conditioned place preference, subjective reports of nicotine effects and nicotine discrimination indicate that nicotine can function as an effective reinforcer of drug-seeking and drug-taking behavior both in experimental animals and humans under appropriate conditions. Interruption of chronic nicotine exposure produces ratings of drug withdrawal and withdrawal symptoms that may contribute to relapse. Difficulties encountered in demonstrating reinforcing effects of nicotine under some conditions, relative to other drugs of abuse, may be due to weaker primary reinforcing effects of nicotine, to aversive effects produced by nicotine, or to a more critical contribution of environmental stimuli to the maintenance of drug-seeking and drug-taking behavior with nicotine than with other drugs of abuse. Several recent reports suggest that other chemical substances inhaled along with nicotine in tobacco smoke may play a role in sustaining smoking behavior. However, conflicting results have been obtained with mice and rats and these findings have not yet been validated in nonhuman primates or human subjects. Taken together, these findings suggest that nicotine acts as a typical drug of abuse in experimental animals and humans in appropriate situations.
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Affiliation(s)
- Bernard Le Foll
- Translational Addiction Research Laboratory, Centre for Addiction and Mental Health, University of Toronto, Toronto, Ontario, Canada
| | - Steven R. Goldberg
- Preclinical Pharmacology Section, Behavioral Neuroscience Research Branch, National Institute on Drug Abuse, National Institutes of Health, Department of Health and Human Services, Baltimore, Maryland, USA
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Liechti ME, Markou A. Role of the glutamatergic system in nicotine dependence : implications for the discovery and development of new pharmacological smoking cessation therapies. CNS Drugs 2008; 22:705-24. [PMID: 18698872 DOI: 10.2165/00023210-200822090-00001] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Preclinical research findings in laboratory animals indicate that the glutamatergic system is critically involved in nicotine dependence. In animals, compounds that decrease glutamatergic neurotransmission, such as antagonists at postsynaptic NMDA receptors, antagonists at excitatory postsynaptic metabotropic glutamate (mGlu) 5 receptors, or agonists at inhibitory presynaptic mGlu(2) and mGlu(3) receptors, decreased nicotine self-administration or reinstatement of nicotine-seeking behaviour. These findings suggest that medications that decrease glutamatergic transmission overall may reduce the reinforcing effects of tobacco smoking and prevent relapse to tobacco smoking in humans. Furthermore, compounds that increase glutamate release, such as antagonists at mGlu(2) and mGlu(3) receptors, ameliorated reward deficits associated with nicotine withdrawal in animals, and thus may alleviate the depression-like symptoms associated with nicotine withdrawal in humans. Animal studies also showed that alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA)/kainate receptors did not appear to be involved in mediating the primary reinforcing effects of nicotine but that they may be involved in the development of nicotine dependence and withdrawal.Taken together, the preclinical data indicate that different glutamatergic receptors are involved in the mediation of different aspects of nicotine dependence. These findings have implications for the discovery and development of new pharmacotherapies that target the glutamatergic system to aid in smoking cessation. At present, very few clinical studies have addressed the effects of glutamatergic compounds on cigarette smoking. Clinical studies involving compounds that have actions at ionotropic glutamate receptors are briefly discussed in this review and suggest the potential of glutamatergic compounds as pharmacotherapies to aid in smoking cessation. Medications that target mGlu receptors have recently been tested in human phase II trials for various indications; however, the potential of these mGlu compounds as medications for nicotine dependence remains to be evaluated in humans. The preclinical data evaluated in this review indicate that such clinical trials for smoking cessation with mGlu compounds are clearly warranted and may reveal novel treatments for nicotine dependence.
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Affiliation(s)
- Matthias E Liechti
- Division of Clinical Pharmacology and Toxicology, University Hospital of Basel, Basel, Switzerland
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Palmatier MI, Coddington SB, Liu X, Donny EC, Caggiula AR, Sved AF. The motivation to obtain nicotine-conditioned reinforcers depends on nicotine dose. Neuropharmacology 2008; 55:1425-30. [PMID: 18809417 PMCID: PMC2873860 DOI: 10.1016/j.neuropharm.2008.09.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2008] [Revised: 09/01/2008] [Accepted: 09/02/2008] [Indexed: 11/15/2022]
Abstract
Stimuli associated with nicotine (NIC) can acquire new meaning via Pavlovian conditioning. If a stimulus is associated with the primary reinforcing effects of NIC, the new conditional properties of the stimulus should make it a more valuable reinforcer (i.e., increase the motivation to obtain the stimulus), and this value should be based, in part, on the strength or intensity of the primary reinforcer (i.e., NIC dose). The purpose of the present study was to investigate whether NIC-conditioned reinforcement increased motivation to obtain non-NIC stimuli, as reflected by performance on a progressive ratio (PR) reinforcement schedule, and whether this increased motivation was systematically related to NIC dose. Two Paired groups were allowed to nose-poke for NIC (0.03 or 0.09mg/kg/infusion, IV) accompanied by 15-s illumination of a stimulus light (conditional stimulus or CS). Two Unpaired groups (0.03 or 0.09mg/kg/infusion) could also make a nose-poke response for the CS; however their NIC infusions were controlled by the Paired group (i.e., yoked design). A fifth group (CS-Only) was allowed to nose-poke for CS presentations and saline infusions. After 29 conditioning sessions the nose-poke operant was prevented by obscuring the receptacle and the CS (accompanied by saline infusion for all groups) was made contingent upon a novel operant response (lever press). During the acquisition of this novel response, each CS/saline infusion earned increased the number of responses required to earn the next CS/saline infusion. Pairings with the primary reinforcing effects of NIC resulted the acquisition of a novel response for the CS. Motivation to obtain the CS depended on salience (dose) of the primary reinforcement (NIC).
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Affiliation(s)
- M I Palmatier
- Department of Psychology, Kansas State University, 469 Bluemont Hall, 1100 Mid Campus Drive, Manhattan, KS 66502, USA.
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Comparison of systemic and local methamphetamine treatment on acetylcholine and dopamine levels in the ventral tegmental area in the mouse. Neuroscience 2008; 156:700-11. [PMID: 18760336 DOI: 10.1016/j.neuroscience.2008.07.052] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2008] [Revised: 07/08/2008] [Accepted: 07/22/2008] [Indexed: 11/21/2022]
Abstract
Acetylcholine (ACh) is an important mediator of dopamine (DA) release and the behavioral reinforcing characteristics of drugs of abuse in the mesocorticolimbic pathway. Within the ventral tegmental area (VTA), the interaction of DA with ACh appears to be integral in mediating motivated behaviors. However, the effects of methamphetamine on VTA ACh and DA release remain poorly characterized. The current investigation performed microdialysis to evaluate the effects of methamphetamine on extracellular levels of ACh and DA. Male C57BL/6J mice received an i.p. injection (saline, 2 mg/kg, or 5 mg/kg) and an intra-VTA infusion (vehicle, 100 microM or 1 mM) of methamphetamine. Locally perfused methamphetamine resulted in no change in extracellular ACh compared with vehicle, but caused a strong, immediate and dose-dependent increase in extrasynaptic DA levels (1240% and 2473% of baseline, respectively) during the 20-min pulse perfusion. An i.p. injection of methamphetamine increased extrasynaptic DA to 275% and 941% of baseline (2 mg/kg and 5 mg/kg, respectively). Systemic methamphetamine significantly increased ACh levels up to 275% of baseline for 40-60 min (2 mg/kg) and 397% of baseline for 40-160 min (5 mg/kg) after injection. ACh remained elevated above baseline for 2-3 h post injection, depending on the methamphetamine dose. Methamphetamine-induced locomotor activity was dose-dependently correlated with extrasynaptic VTA ACh, but not DA levels. These data suggest that methamphetamine acts in the VTA to induce a robust and short-lived increase in extracellular DA release but acts in an area upstream from the VTA to produce a prolonged increase in ACh release in the VTA. We conclude that methamphetamine may activate a recurrent loop in the mesocorticolimbic DA system to stimulate pontine cholinergic nuclei and produce a prolonged ACh release in the VTA.
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Dwoskin LP, Wooters TE, Sumithran SP, Siripurapu KB, Joyce BM, Lockman PR, Manda VK, Ayers JT, Zhang Z, Deaciuc AG, McIntosh JM, Crooks PA, Bardo MT. N,N'-Alkane-diyl-bis-3-picoliniums as nicotinic receptor antagonists: inhibition of nicotine-evoked dopamine release and hyperactivity. J Pharmacol Exp Ther 2008; 326:563-76. [PMID: 18460644 DOI: 10.1124/jpet.108.136630] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The current study evaluated a new series of N,N'-alkane-diyl-bis-3-picolinium (bAPi) analogs with C6-C12 methylene linkers as nicotinic acetylcholine receptor (nAChR) antagonists, for nicotine-evoked [3H]dopamine (DA) overflow, for blood-brain barrier choline transporter affinity, and for attenuation of discriminative stimulus and locomotor stimulant effects of nicotine. bAPi analogs exhibited little affinity for alpha4beta2* (* indicates putative nAChR subtype assignment) and alpha7* high-affinity ligand binding sites and exhibited no inhibition of DA transporter function. With the exception of C6, all analogs inhibited nicotine-evoked [3H]DA overflow (IC50 = 2 nM-6 microM; Imax = 54-64%), with N,N'-dodecane-1,12-diyl-bis-3-picolinium dibromide (bPiDDB; C12) being most potent. bPiDDB did not inhibit electrically evoked [3H]DA overflow, suggesting specific nAChR inhibitory effects and a lack of toxicity to DA neurons. Schild analysis suggested that bPiDDB interacts in an orthosteric manner at nAChRs mediating nicotine-evoked [3H]DA overflow. To determine whether bPiDDB interacts with alpha-conotoxin MII-sensitive alpha6beta2-containing nAChRs, slices were exposed concomitantly to maximally effective concentrations of bPiDDB (10 nM) and alpha-conotoxin MII (1 nM). Inhibition of nicotine-evoked [3H]DA overflow was not different with the combination compared with either antagonist alone, suggesting that bPiDDB interacts with alpha6beta2-containing nAChRs. C7, C8, C10, and C12 analogs exhibited high affinity for the blood-brain barrier choline transporter in vivo, suggesting brain bioavailability. Although none of the analogs altered the discriminative stimulus effect of nicotine, C8, C9, C10, and C12 analogs decreased nicotine-induced hyperactivity in nicotine-sensitized rats, without reducing spontaneous activity. Further development of nAChR antagonists that inhibit nicotine-evoked DA release and penetrate brain to antagonize DA-mediated locomotor stimulant effects of nicotine as novel treatments for nicotine addiction is warranted.
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Affiliation(s)
- Linda P Dwoskin
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, KY 40536-0082, USA.
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Liu X, Caggiula AR, Palmatier MI, Donny EC, Sved AF. Cue-induced reinstatement of nicotine-seeking behavior in rats: effect of bupropion, persistence over repeated tests, and its dependence on training dose. Psychopharmacology (Berl) 2008; 196:365-75. [PMID: 17932656 PMCID: PMC2812900 DOI: 10.1007/s00213-007-0967-9] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2007] [Accepted: 09/23/2007] [Indexed: 10/22/2022]
Abstract
RATIONALE The motivational effects of nicotine-associated cues have been demonstrated in animal studies. However, it is unknown whether the effectiveness of nicotine cues in reinstating nicotine-seeking varies with the extent of prior nicotine self-administration. In addition, the issue of whether bupropion (an FDA-approved smoking cessation medication) interferes with the conditioned incentive of nicotine cues remains to be addressed. OBJECTIVE This study determined the relationship of cue-reinstated nicotine-seeking and the levels of prior self-administration and examined the effect of bupropion on cue-induced reinstatement of nicotine-seeking in comparison with that on self-administration. MATERIALS AND METHODS Male Sprague-Dawley rats were trained in daily 1-h sessions to intravenously self-administer nicotine at different doses (0, 0.015, 0.03, 0.06 mg/kg/infusion) and to associate an auditory/visual cue with each nicotine delivery. After extinction, three reinstatement tests at 15 day intervals were conducted with re-presentation of the cue without nicotine delivery. In separate groups of rats trained with 0.03 mg/kg/infusion nicotine, bupropion (0, 10, 20, 40 mg/kg) was intraperitoneally administered to different groups before the reinstatement and in a within-subject design before the self-administration tests. RESULTS Cue-induced reinstatement of active lever responses was observed at all nicotine doses in the first reinstatement test, but at only the two highest doses during the second and third tests. The magnitude of reinstatement was positively correlated with level of prior responding for nicotine. Bupropion pretreatment decreased nicotine self-administration but enhanced cue-reinstated nicotine-seeking. CONCLUSIONS These results demonstrate the positive correlation of cue-reinstated nicotine-seeking with prior responding for nicotine self-administration and the persistence of the cue effect after taking higher doses of nicotine. The results of pharmacological tests suggest that although it is able to help achieve smoking cessation, bupropion may have little clinical benefit for the prevention of relapse associated with exposure to environmental smoking cues.
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Affiliation(s)
- Xiu Liu
- Department of Psychology, University of Pittsburgh, Pittsburgh, PA 15260, USA.
| | - Anthony R. Caggiula
- Department of Psychology, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | | | - Eric C. Donny
- Department of Psychology, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Alan F. Sved
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260, USA
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