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Chen G, Ghazal M, Rahman S, Lutfy K. The impact of adolescent nicotine exposure on alcohol use during adulthood: The role of neuropeptides. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2021; 161:53-93. [PMID: 34801174 DOI: 10.1016/bs.irn.2021.07.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Nicotine and alcohol abuse and co-dependence represent major public health crises. Indeed, previous research has shown that the prevalence of alcoholism is higher in smokers than in non-smokers. Adolescence is a susceptible period of life for the initiation of nicotine and alcohol use and the development of nicotine-alcohol codependence. However, there is a limited number of pharmacotherapeutic agents to treat addiction to nicotine or alcohol alone. Notably, there is no effective medication to treat this comorbid disorder. This chapter aims to review the early nicotine use and its impact on subsequent alcohol abuse during adolescence and adulthood as well as the role of neuropeptides in this comorbid disorder. The preclinical and clinical findings discussed in this chapter will advance our understanding of this comorbid disorder's neurobiology and lay a foundation for developing novel pharmacotherapies to treat nicotine and alcohol codependence.
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Affiliation(s)
- G Chen
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA, United States; Department of Pharmaceutical Sciences, College of Pharmacy, Western University of Health Sciences, Pomona, CA, United States
| | - M Ghazal
- Department of Pharmaceutical Sciences, College of Pharmacy, Western University of Health Sciences, Pomona, CA, United States
| | - S Rahman
- Department of Pharmaceutical Sciences, South Dakota State University, Brookings, SD, United States
| | - K Lutfy
- Department of Pharmaceutical Sciences, College of Pharmacy, Western University of Health Sciences, Pomona, CA, United States.
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2
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Mooney-Leber SM, Caruso MJ, Gould TJ, Cavigelli SA, Kamens HM. The impact of adolescent stress on nicotine use and affective disorders in rodent models. Eur J Neurosci 2021; 55:2196-2215. [PMID: 34402112 PMCID: PMC9730548 DOI: 10.1111/ejn.15421] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 07/23/2021] [Accepted: 07/28/2021] [Indexed: 12/19/2022]
Abstract
Recent findings indicate that stress exposure during adolescence contributes to the development of both nicotine use and affective disorders, suggesting a potential shared biological pathway. One key system that may mediate the association between adolescent stress and nicotine or affective outcomes is the hypothalamic-pituitary-adrenal (HPA) axis. Here we reviewed evidence regarding the effects of adolescent stress on nicotine responses and affective phenotypes and the role of the HPA-axis in these relationships. Literature indicates that stress, possibly via HPA-axis dysfunction, is a risk factor for both nicotine use and affective disorders. In rodent models, adolescent stress modulates behavioural responses to nicotine and increases the likelihood of affective disorders. The exact role that the HPA-axis plays in altering nicotine sensitivity and affective disorder development after adolescent stress remains unclear. However, it appears likely that adolescent stress-induced nicotine use and affective disorders are precipitated by repetitive activation of a hyperactive HPA-axis. Together, these preclinical studies indicate that adolescent stress is a risk factor for nicotine use and anxiety/depression phenotypes. The findings summarized here suggest that the HPA-axis mediates this relationship. Future studies that pharmacologically manipulate the HPA-axis during and after adolescent stress are critical to elucidate the exact role that the HPA-axis plays in the development of nicotine use and affective disorders following adolescent stress.
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Affiliation(s)
- Sean M Mooney-Leber
- Department of Biobehavioral Health, The Pennsylvania State University, University Park, PA, USA.,Department of Psychology, University of Wisconsin - Stevens Point, Stevens Point, WI, USA
| | - Michael J Caruso
- Department of Biobehavioral Health, The Pennsylvania State University, University Park, PA, USA
| | - Thomas J Gould
- Department of Biobehavioral Health, The Pennsylvania State University, University Park, PA, USA
| | - Sonia A Cavigelli
- Department of Biobehavioral Health, The Pennsylvania State University, University Park, PA, USA.,Center for Brain, Behavior, and Cognition, The Pennsylvania State University, University Park, PA, USA
| | - Helen M Kamens
- Department of Biobehavioral Health, The Pennsylvania State University, University Park, PA, USA.,Center for Brain, Behavior, and Cognition, The Pennsylvania State University, University Park, PA, USA
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3
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Raffetti E, Andersson F, Donato F, Kong L, Efstathopoulos P, Lavebratt C, Forsell Y, Galanti MR. No association of cigarette smoking and depressive symptoms with cortisol concentration in adolescents. Results from a population-based Swedish cohort. Psychiatry Res 2021; 301:113968. [PMID: 33984825 DOI: 10.1016/j.psychres.2021.113968] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Accepted: 04/20/2021] [Indexed: 10/21/2022]
Abstract
Several studies have shown that smoking increases the risk of depressive symptoms, and suggested a possible role of the hypothalamic-pituitary-adrenal axis in the smoking-depression pathway. This study aimed to assess if smokers have higher cortisol levels than non-smokers, and if higher cortisol levels are associated with depressive symptoms. Saliva samples were collected from a subgroup of 409 participants at enrolment (13-14 years old) and two years later (15-16 years old). First, we examined the association between smoking phenotypes and cortisol concentration. Second, we evaluated whether these associations differed between adolescents with and without depressive symptoms. The mean difference between smokers and non-smokers in cortisol concentrations was close to zero at both time points. For instance, the adjusted mean difference for morning cortisol concentration between current and non-current smokers was 0.000 µg/dl [95% CI -0.055, 0.056]. In addition, there were no differences in cortisol concentration at the second time-point between those who had smoked and those who did not during the two previous years. Moreover, cortisol levels were not associated with depressive symptoms. The hypothesis that dysregulation of the hypothalamic-pituitary-adrenal axis might be involved in the association between smoking behavior and depressive symptoms during adolescence was not supported by this data.
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Affiliation(s)
- Elena Raffetti
- Department of Global Public Health, Karolinska Institutet, Stockholm, Sweden.
| | - Filip Andersson
- Department of Global Public Health, Karolinska Institutet, Stockholm, Sweden; Centre for Epidemiology and Community Medicine, Stockholm Region, Stockholm, Sweden
| | - Francesco Donato
- Unit of Hygiene, Epidemiology and Public Health, University of Brescia, Brescia, Italy
| | - Linghua Kong
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden; Center for Molecular Medicine, Karolinska University Hospital, Stockholm, Sweden
| | - Paschalis Efstathopoulos
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden; Center for Molecular Medicine, Karolinska University Hospital, Stockholm, Sweden
| | - Catharina Lavebratt
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden; Center for Molecular Medicine, Karolinska University Hospital, Stockholm, Sweden
| | - Yvonne Forsell
- Department of Global Public Health, Karolinska Institutet, Stockholm, Sweden; Centre for Epidemiology and Community Medicine, Stockholm Region, Stockholm, Sweden
| | - Maria Rosaria Galanti
- Department of Global Public Health, Karolinska Institutet, Stockholm, Sweden; Centre for Epidemiology and Community Medicine, Stockholm Region, Stockholm, Sweden
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Lutz JA, Childs E. Alcohol conditioned contexts enhance positive subjective alcohol effects and consumption. Behav Processes 2021; 187:104340. [PMID: 33545315 DOI: 10.1016/j.beproc.2021.104340] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2020] [Revised: 06/15/2020] [Accepted: 01/26/2021] [Indexed: 10/22/2022]
Abstract
Associations between alcohol and the places it is consumed are important at all stages of alcohol abuse and addiction. However, it is not clear how the associations are formed in humans or how they influence drinking, and there are few effective strategies to prevent their pathological effects on alcohol use. We used a human laboratory model to study the effects of alcohol environments on alcohol consumption. Healthy regular binge drinkers completed conditioned place preference (CPP) with 0 vs. 80 mg/100 mL alcohol (Paired Group). Control participants (Unpaired Group) completed sessions without explicit alcohol-room pairings. After conditioning, participants completed alcohol self-administration in either the alcohol- or no alcohol-paired room. Paired group participants reported greater subjective stimulation and euphoria, and consumed more alcohol in the alcohol-paired room in comparison to the no alcohol-paired room, and controls tested in either room. Moreover, the strength of conditioning significantly predicted drinking; participants who exhibited the strongest CPP consumed the most alcohol in the alcohol-paired room. This is the first empirical evidence that laboratory-conditioned alcohol environments directly influence drinking. The results also confirm the viability of the model to examine the mechanisms by which alcohol environments stimulate drinking and to test strategies to counteract their influence on behavior.
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Affiliation(s)
- Joseph A Lutz
- University of Illinois at Chicago, Department of Psychiatry, 1601 W Taylor St MC912, Chicago, IL, 60612, USA
| | - Emma Childs
- University of Illinois at Chicago, Department of Psychiatry, 1601 W Taylor St MC912, Chicago, IL, 60612, USA; University of Chicago, Department of Psychiatry and Behavioral Neuroscience, 5841 S. Maryland Avenue, Chicago, IL, 60637, USA.
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Vaporized Cannabis Extracts Have Reinforcing Properties and Support Conditioned Drug-Seeking Behavior in Rats. J Neurosci 2020; 40:1897-1908. [PMID: 31953372 DOI: 10.1523/jneurosci.2416-19.2020] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 01/03/2020] [Accepted: 01/08/2020] [Indexed: 01/11/2023] Open
Abstract
Recent trends in cannabis legalization have increased the necessity to better understand the effects of cannabis use. Animal models involving traditional cannabinoid self-administration approaches have been notoriously difficult to establish and differences in the drug used and its route of administration have limited the translational value of preclinical studies. To address this challenge in the field, we have developed a novel method of cannabis self-administration using response-contingent delivery of vaporized Δ9-tetrahydrocannabinol-rich (CANTHC) or cannabidiol-rich (CANCBD) whole-plant cannabis extracts. Male Sprague-Dawley rats were trained to nose-poke for discrete puffs of CANTHC, CANCBD, or vehicle (VEH) in daily 1 h sessions. Cannabis vapor reinforcement resulted in strong discrimination between active and inactive operanda. CANTHC maintained higher response rates under fixed ratio schedules and higher break points under progressive ratio schedules compared with CANCBD or VEH, and the number of vapor deliveries positively correlated with plasma THC concentrations. Moreover, metabolic phenotyping studies revealed alterations in locomotor activity, energy expenditure, and daily food intake that are consistent with effects in human cannabis users. Furthermore, both cannabis regimens produced ecologically relevant brain concentrations of THC and CBD and CANTHC administration decreased hippocampal CB1 receptor binding. Removal of CANTHC reinforcement (but not CANCBD) resulted in a robust extinction burst and an increase in cue-induced cannabis-seeking behavior relative to VEH. These data indicate that volitional exposure to THC-rich cannabis vapor has bona fide reinforcing properties and collectively support the utility of the vapor self-administration model for the preclinical assessment of volitional cannabis intake and cannabis-seeking behaviors.SIGNIFICANCE STATEMENT The evolving legal landscape concerning recreational cannabis use has increased urgency to better understand its effects on the brain and behavior. Animal models are advantageous in this respect; however, current approaches typically used forced injections of synthetic cannabinoids or isolated cannabis constituents that may not capture the complex effects of volitional cannabis consumption. We have developed a novel model of cannabis self-administration using response-contingent delivery of vaporized cannabis extracts containing high concentrations of Δ9 tetrahydrocannabinol (THC) or cannabidiol. Our data indicate that THC-rich cannabis vapor has reinforcing properties that support stable rates of responding and conditioned drug-seeking behavior. This approach will be valuable for interrogating effects of cannabis and delineating neural mechanisms that give rise to aberrant cannabis-seeking behavior.
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Wemm SE, Sinha R. Drug-induced stress responses and addiction risk and relapse. Neurobiol Stress 2019; 10:100148. [PMID: 30937354 PMCID: PMC6430516 DOI: 10.1016/j.ynstr.2019.100148] [Citation(s) in RCA: 77] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 12/07/2018] [Accepted: 01/30/2019] [Indexed: 12/21/2022] Open
Abstract
A number of studies have assessed the effects of psychoactive drugs on stress biology, the neuroadaptations resulting from chronic drug use on stress biology, and their effects on addiction risk and relapse. This review mainly covers human research on the acute effects of different drugs of abuse (i.e., nicotine, cannabis, psychostimulants, alcohol, and opioids) on the hypothalamic-pituitary-adrenal (HPA) axis and the autonomic nervous system (ANS) responses. We review the literature on acute peripheral stress responses in naïve or light recreational users and binge/heavy or chronic drug users. We also discuss evidence of alterations in tonic levels, or tolerance, in the latter relative to the former and associated changes in the phasic stress responses. We discuss the impact of the stress system tolerance in heavy users on their response to drug- and stress-related cue responses and craving as compared to control subjects. A summary is provided of the effects of glucocorticoid responses and their adaptations on brain striatal and prefrontal cortices involved in the regulation of drug seeking and relapse risk. Finally, we summarize important considerations, including individual difference factors such as gender, co-occurring drug use, early trauma and adversity and drug use history and variation in methodologies, that may further influence the effects of these drugs on stress biology.
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Affiliation(s)
- Stephanie E. Wemm
- Yale Stress Center, Yale School of Medicine, 2 Church St South Suite 209, New Haven, CT, 06519, USA
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Oakes JM, Fuchs RM, Gardner JD, Lazartigues E, Yue X. Nicotine and the renin-angiotensin system. Am J Physiol Regul Integr Comp Physiol 2018; 315:R895-R906. [PMID: 30088946 DOI: 10.1152/ajpregu.00099.2018] [Citation(s) in RCA: 202] [Impact Index Per Article: 33.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Cigarette smoking is the single most important risk factor for the development of cardiovascular and pulmonary diseases (CVPD). Although cigarette smoking has been in constant decline since the 1950s, the introduction of e-cigarettes or electronic nicotine delivery systems 10 yr ago has attracted former smokers as well as a new generation of consumers. Nicotine is a highly addictive substance, and it is currently unclear whether e-cigarettes are "safer" than regular cigarettes or whether they have the potential to reverse the health benefits, notably on the cardiopulmonary system, acquired with the decline of tobacco smoking. Of great concern, nicotine inhalation devices are becoming popular among young adults and youths, emphasizing the need for awareness and further study of the potential cardiopulmonary risks of nicotine and associated products. This review focuses on the interaction between nicotine and the renin-angiotensin system (RAS), one of the most important regulatory systems on autonomic, cardiovascular, and pulmonary functions in both health and disease. The literature presented in this review strongly suggests that nicotine alters the homeostasis of the RAS by upregulating the detrimental angiotensin-converting enzyme (ACE)/angiotensin (ANG)-II/ANG II type 1 receptor axis and downregulating the compensatory ACE2/ANG-(1-7)/Mas receptor axis, contributing to the development of CVPD.
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Affiliation(s)
- Joshua M Oakes
- Department of Physiology, Louisiana State University Health Sciences Center , New Orleans, Louisiana
| | - Robert M Fuchs
- Department of Pharmacology and Experimental Therapeutics, Louisiana State University Health Sciences Center , New Orleans, Louisiana
| | - Jason D Gardner
- Department of Physiology, Louisiana State University Health Sciences Center , New Orleans, Louisiana
| | - Eric Lazartigues
- Department of Pharmacology and Experimental Therapeutics, Louisiana State University Health Sciences Center , New Orleans, Louisiana
| | - Xinping Yue
- Department of Physiology, Louisiana State University Health Sciences Center , New Orleans, Louisiana
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8
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Rupprecht LE, Kreisler AD, Spierling SR, de Guglielmo G, Kallupi M, George O, Donny EC, Zorrilla EP, Sved AF. Self-administered nicotine increases fat metabolism and suppresses weight gain in male rats. Psychopharmacology (Berl) 2018; 235:1131-1140. [PMID: 29354872 PMCID: PMC8162771 DOI: 10.1007/s00213-018-4830-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Accepted: 01/03/2018] [Indexed: 12/16/2022]
Abstract
RATIONALE The ability of nicotine to suppress body weight is cited as a factor impacting smoking initiation and the failure to quit. Self-administered nicotine in male rats suppresses weight independent of food intake, suggesting that nicotine increases energy expenditure. OBJECTIVE The current experiment evaluated the impact of self-administered nicotine on metabolism in rats using indirect calorimetry and body composition analysis. METHODS Adult male rats with ad libitum access to powdered standard rodent chow self-administered intravenous infusions of nicotine (60 μg/kg/infusion or saline control) in daily 1-h sessions in the last hour of the light cycle. Indirect calorimetry measured respiratory exchange ratio (RER), energy expenditure, motor activity, and food and water consumption for 22.5 h between select self-administration sessions. RESULTS Self-administered nicotine suppressed weight gain and reduced the percent of body fat without altering the percent of lean mass, as measured by Echo MRI. Nicotine reduced RER, indicating increased fat utilization; this effect was observed prior to weight suppression. Moreover, nicotine intake did not affect motor activity or energy expenditure. Daily food intake was not altered by nicotine self-administration; however, a trend in suppression of meal size, a transient suppression of water intake, and an increase in meal frequency was observed. CONCLUSION These data provide evidence that self-administered nicotine suppresses body weight via increased fat metabolism, independent of significant changes in feeding, activity, or energy expenditure.
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Affiliation(s)
| | - Alison D. Kreisler
- Department of Neuroscience, The Scripps Research Institute, La Jolla, CA, USA
| | | | | | - Marsida Kallupi
- Department of Neuroscience, The Scripps Research Institute, La Jolla, CA, USA
| | - Olivier George
- Department of Neuroscience, The Scripps Research Institute, La Jolla, CA, USA
| | - Eric C. Donny
- Department of Psychology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Eric P. Zorrilla
- Department of Neuroscience, The Scripps Research Institute, La Jolla, CA, USA
| | - Alan F. Sved
- Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA,Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA
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9
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Habitual nicotine-seeking in rats following limited training. Psychopharmacology (Berl) 2017; 234:2619-2629. [PMID: 28589264 DOI: 10.1007/s00213-017-4655-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Accepted: 05/19/2017] [Indexed: 10/19/2022]
Abstract
RATIONALE AND OBJECTIVES A potential reason that cigarette smoking can persist despite multiple quit attempts is that repeated voluntary nicotine intake may facilitate a transition from goal-directed to habitual behavioral control. Although accelerated habit formation for self-administered ethanol or cocaine has been previously demonstrated, this phenomenon has not been extensively studied with nicotine. We therefore examined the liability of nicotine self-administration to become habitual, while also examining that of orally consumed saccharin as an experimental control. METHODS Under fixed ratio 1 (FR-1) schedules, male Sprague-Dawley rats (n = 8-11/group) lever-pressed for intravenous (IV) nicotine (30 μg/kg/infusion) for 10 consecutive days, while also lever-pressing for saccharin solution (0.1% w/v, 0.19 mL/delivery) in separate operant sessions. In experiment 1, either nicotine or saccharin was devalued by pairing with the aversive agent lithium chloride (LiCl; 0.15 M, 14.1 mL/kg) prior to extinction and reacquisition testing. In experiment 2, the contingency between lever pressing and delivery of either nicotine or saccharin was degraded in six sessions, followed by extinction testing. RESULTS LiCl pairings selectively reduced responding for nicotine (-35% from control) and saccharin (-48%) in reacquisition testing, indicating that both rewards were effectively devalued. During extinction testing, saccharin-seeking responses were reduced by both manipulations (devaluation -30%, degradation -79%), suggesting that responding for saccharin was goal-directed. In contrast, nicotine-seeking responses were not significantly affected by either manipulation (devaluation -4%, degradation -21%), suggesting that responding for nicotine was habitually driven. CONCLUSIONS Operant responding for IV nicotine may rapidly come under habitual control, potentially contributing to the tenacity of tobacco use.
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10
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Frenk H, Martin J, Vitouchanskaia C, Dar R, Shalev U. Effects of contingent and noncontingent nicotine on lever pressing for liquids and consumption in water-deprived rats. Eur J Pharmacol 2017; 794:224-233. [DOI: 10.1016/j.ejphar.2016.11.035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Revised: 11/21/2016] [Accepted: 11/21/2016] [Indexed: 11/29/2022]
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Packard AEB, Egan AE, Ulrich-Lai YM. HPA Axis Interactions with Behavioral Systems. Compr Physiol 2016; 6:1897-1934. [PMID: 27783863 DOI: 10.1002/cphy.c150042] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Perhaps the most salient behaviors that individuals engage in involve the avoidance of aversive experiences and the pursuit of pleasurable experiences. Engagement in these behaviors is regulated to a significant extent by an individual's hormonal milieu. For example, glucocorticoid hormones are produced by the hypothalamic-pituitary-adrenocortical (HPA) axis, and influence most aspects of behavior. In turn, many behaviors can influence HPA axis activity. These bidirectional interactions not only coordinate an individual's physiological and behavioral states to each other, but can also tune them to environmental conditions thereby optimizing survival. The present review details the influence of the HPA axis on many types of behavior, including appetitively-motivated behaviors (e.g., food intake and drug use), aversively-motivated behaviors (e.g., anxiety-related and depressive-like) and cognitive behaviors (e.g., learning and memory). Conversely, the manuscript also describes how engaging in various behaviors influences HPA axis activity. Our current understanding of the neuronal and/or hormonal mechanisms that underlie these interactions is also summarized. © 2016 American Physiological Society. Compr Physiol 6:1897-1934, 2016.
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Affiliation(s)
- Amy E B Packard
- Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati, Cincinnati, Ohio, USA
| | - Ann E Egan
- Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati, Cincinnati, Ohio, USA
| | - Yvonne M Ulrich-Lai
- Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati, Cincinnati, Ohio, USA
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12
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O'Rourke KY, Touchette JC, Hartell EC, Bade EJ, Lee AM. Voluntary co-consumption of alcohol and nicotine: Effects of abstinence, intermittency, and withdrawal in mice. Neuropharmacology 2016; 109:236-246. [PMID: 27342124 DOI: 10.1016/j.neuropharm.2016.06.023] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2015] [Revised: 06/16/2016] [Accepted: 06/21/2016] [Indexed: 11/17/2022]
Abstract
Alcohol and nicotine are often used together, and there is a high rate of co-occurrence between alcohol and nicotine addiction. Most animal models studying alcohol and nicotine interactions have utilized passive drug administration, which may not be relevant to human co-addiction. In addition, the interactions between alcohol and nicotine in female animals have been understudied, as most studies have used male animals. To address these issues, we developed models of alcohol and nicotine co-consumption in male and female mice that utilized voluntary, oral consumption of unsweetened alcohol, nicotine and water. We first examined drug consumption and preference in single-drug, sequential alcohol and nicotine consumption tests in male and female C57BL/6 and DBA/2J mice. We then tested chronic continuous and intermittent access alcohol and nicotine co-consumption procedures. We found that male and female C57BL/6 mice readily co-consumed unsweetened alcohol and nicotine. In our continuous co-consumption procedures, we found that varying the available nicotine concentration during an alcohol abstinence period affected compensatory nicotine consumption during alcohol abstinence, and affected rebound alcohol consumption when alcohol was re-introduced. Consumption of alcohol and nicotine in an intermittent co-consumption procedure produced higher alcohol consumption levels, but not nicotine consumption levels, compared with the continuous co-consumption procedures. Finally, we found that intermittent alcohol and nicotine co-consumption resulted in physical dependence. Our data show that these voluntary co-consumption procedures can be easily performed in mice and can be used to study behavioral interactions between alcohol and nicotine consumption, which may better model human alcohol and nicotine co-addiction.
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Affiliation(s)
- Kyu Y O'Rourke
- Department of Pharmacology, University of Minnesota, Minneapolis, MN, 55455, USA
| | | | - Elizabeth C Hartell
- Department of Pharmacology, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Elizabeth J Bade
- Department of Pharmacology, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Anna M Lee
- Department of Pharmacology, University of Minnesota, Minneapolis, MN, 55455, USA.
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13
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A key role for the N/OFQ-NOP receptor system in modulating nicotine taking in a model of nicotine and alcohol co-administration. Sci Rep 2016; 6:26594. [PMID: 27199205 PMCID: PMC4873733 DOI: 10.1038/srep26594] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Accepted: 05/05/2016] [Indexed: 11/08/2022] Open
Abstract
Alcohol and nicotine are often co-abused. Although the N/OFQ-NOP receptor system is considered a potential target for development of drug abuse pharmacotherapies, especially for alcoholism, little is known about the role of this system in nicotine dependence. Furthermore, the effect of prior history of nicotine dependence on subsequent nicotine and alcohol taking is understudied. Using an operant co-administration paradigm, in which rats concurrently self-administer nicotine and alcohol, we found that nicotine dependent rats increased nicotine self-administration over time as compared to non-dependent animals, while patterns of alcohol lever pressing did not change between groups. Pretreatment with the potent NOP receptor agonist AT-202 (0.3–3 mg/kg) increased nicotine lever pressing of both dependent and non-dependent groups, whereas the selective antagonist SB612111 (1–10 mg/kg) elicited a clear reduction of nicotine responses, in both dependent and non-dependent rats. In parallel, AT-202 only produced minor changes on alcohol responses and SB612111 reduced alcohol taking at a dose that also reduced locomotor behavior. Results indicate that a history of nicotine dependence affects subsequent nicotine- but not alcohol-maintained responding, and that NOP receptor antagonism, rather than agonism, blocks nicotine self-administration, which strongly suggests a critical role for the endogenous N/OFQ in the modulation of nicotine reinforcement processes.
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Rupprecht LE, Smith TT, Donny EC, Sved AF. Self-Administered Nicotine Suppresses Body Weight Gain Independent of Food Intake in Male Rats. Nicotine Tob Res 2016; 18:1869-1876. [PMID: 27194544 DOI: 10.1093/ntr/ntw113] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Accepted: 03/31/2016] [Indexed: 01/19/2023]
Abstract
INTRODUCTION The action of nicotine to suppress body weight is often cited as a factor impacting smoking initiation and the failure to quit. Despite the weight-suppressant effects of nicotine, smokers and nonsmokers report equal daily caloric intake. The weight-suppressive effects of nicotine in animal models of smoking are poorly understood. Furthermore, the Food and Drug Administration has authority to implement a policy markedly reducing nicotine levels in cigarettes; such a reduction could reduce smoking behavior, but have detrimental effects on body weight. The aim of this investigation was to examine the effects of self-administered nicotine on body weight and food intake in rats. METHODS In Experiment 1, rats with ad libitum access to chow responded for intravenous infusions of nicotine (60 µg/kg/infusion) or saline in daily 1-hour sessions; body weight and 24-hour food intake were measured. Experiment 2 tested the effects of subcutaneous injections of nicotine on food intake. In Experiment 3, rats were food restricted and self-administered nicotine across a range of doses (3.75-60 µg/kg/infusion) while body weight was measured. In Experiment 4, rats self-administered 60 µg/kg/infusion nicotine before reduction to one of several doses (1.875-15 µg/kg/infusion) for 50 days. RESULTS Self-administered nicotine suppressed weight gain independent of food intake. In food restricted rats, self-administered nicotine dose-dependently suppressed body weight gain. In rats self-administering 60 µg/kg/infusion nicotine, dose reduction increased body weight. CONCLUSIONS Self-administered nicotine, even at low doses, suppressed body independent of food intake; this may have important implications for nicotine reduction policy. IMPLICATIONS The results of the present studies demonstrate that self-administered nicotine suppresses body weight independent of food intake in rats. Further, the present studies establish that self-administered nicotine suppresses body weight even at very low doses and that reduction of nicotine dose results in weight gain. These results have important implications for nicotine reduction policy.
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Affiliation(s)
| | - Tracy T Smith
- Department of Psychology, University of Pittsburgh , Pittsburgh, PA
| | - Eric C Donny
- Department of Psychology, University of Pittsburgh , Pittsburgh, PA
| | - Alan F Sved
- Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA
- Department of Psychology, University of Pittsburgh, Pittsburgh, PA
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA
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Bunney PE, Burroughs D, Hernandez C, LeSage MG. The effects of nicotine self-administration and withdrawal on concurrently available chow and sucrose intake in adult male rats. Physiol Behav 2016; 154:49-59. [PMID: 26548500 PMCID: PMC5022775 DOI: 10.1016/j.physbeh.2015.11.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Revised: 10/17/2015] [Accepted: 11/03/2015] [Indexed: 12/17/2022]
Abstract
Carbohydrate intake, preference, and taste thresholds may be altered in current and former cigarette smokers, which may mediate weight gain and risk for obesity in individuals who quit smoking. Attempts to model these effects in rodents have primarily used noncontingent nicotine administration. The purpose of this research was to characterize changes in chow and sucrose intake in rats during a 23-h access model of i.v. nicotine self-administration (NSA), in which rats lever-pressed for chow, sucrose, and nicotine under concurrent fixed-ratio (FR) 1 schedules. Male rats were assigned to one of three groups that differed in food and drug availability. The Nicotine C+S group had concurrent access to nicotine, chow, and sucrose. The Saline C+S group had access to saline, chow, and sucrose. The Nicotine C-Only group had access to nicotine and chow, but not sucrose. Changes in food intake and weight gain were assessed during baseline, NSA, and nicotine withdrawal (i.e., saline extinction). Weight gain was significantly slowed during NSA and increased during withdrawal, but did not differ between the nicotine groups. NSA produced a significant decrease in both chow and sucrose intake. Gradual tolerance to nicotine's effects on sucrose, but not chow intake, occurred. During withdrawal, chow and sucrose intake increased, with a larger percent increase in sucrose intake compared to chow. The proportion of total food intake from sucrose was greater at the end of withdrawal compared to baseline, indicating a history of nicotine intake changed dietary preference. Combined, these results indicate that sucrose intake is more resistant to nicotine's appetite suppressant effects and withdrawal from nicotine produces a greater increase in sweet food intake alongside general increases in chow intake. Changes in overall food intake in current and ex-smokers may lead to increased risk for obesity and other health problems, potentially limiting the benefit of quitting smoking.
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Affiliation(s)
- Patricia E Bunney
- Department of Medicine, Minneapolis Medical Research Foundation, 701 Park Ave., Minneapolis, MN 55415, United States; Department of Medicine, University of Minnesota School of Medicine, 420 Delaware St. SE, Minneapolis, MN 55455, United States.
| | - Danielle Burroughs
- Department of Medicine, Minneapolis Medical Research Foundation, 701 Park Ave., Minneapolis, MN 55415, United States
| | - Christine Hernandez
- Department of Medicine, Minneapolis Medical Research Foundation, 701 Park Ave., Minneapolis, MN 55415, United States
| | - Mark G LeSage
- Department of Medicine, Minneapolis Medical Research Foundation, 701 Park Ave., Minneapolis, MN 55415, United States; Department of Medicine, University of Minnesota School of Medicine, 420 Delaware St. SE, Minneapolis, MN 55455, United States; Department of Psychology, University of Minnesota, N218 Elliot Hall, 75 E River Rd., Minneapolis, MN 55455, United States
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16
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Brynildsen JK, Najar J, Hsu LM, Vaupel DB, Lu H, Ross TJ, Yang Y, Stein EA. A novel method to induce nicotine dependence by intermittent drug delivery using osmotic minipumps. Pharmacol Biochem Behav 2016; 142:79-84. [PMID: 26751248 DOI: 10.1016/j.pbb.2015.12.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Revised: 12/23/2015] [Accepted: 12/30/2015] [Indexed: 11/30/2022]
Abstract
Although osmotic minipumps are a reliable method for inducing nicotine dependence in rodents, continuous nicotine administration does not accurately model the intermittent pattern of nicotine intake in cigarette smokers. Our objectives, therefore, were to investigate whether intermittent nicotine delivery via osmotic minipumps could induce dependence in rats, and to compare the magnitude and duration of withdrawal following forced abstinence from intermittent nicotine to that induced by continuous nicotine administration. In order to administer nicotine intermittently, rats were surgically implanted with saline-filled osmotic minipumps attached to polyethylene tubing that contained hourly unit doses of nicotine alternating with mineral oil to mimic "injections". Three doses of nicotine (1.2, 2.4, and 4.8mg/kg/day) and saline were administered for 14days using this method. In order to compare our intermittent delivery method with the more traditional continuous nicotine delivery, a second group of rats was implanted with minipumps attached to tubing that delivered continuous nicotine for 14days. Rats were administered a 1.5mg/kg subcutaneous (SC) mecamylamine challenge and observed for somatic signs of withdrawal on days 7, 14, 21, and 28 following minipump implantation. Fifteen somatic withdrawal signs were summed within a 50-minute observation period to obtain a composite Dependence Score. A generalized linear mixed-effects model revealed a significant Day×Dose×Method interaction. Amongst continuously-treated rats, only 4.8mg/kg/d nicotine resulted in dependence scores significantly greater than those of controls at 14days of exposure. In contrast, all intermittent nicotine groups showed significantly higher scores beginning at 7days of exposure and persisting beyond 7days of abstinence. In general, intermittent delivery produced a more robust withdrawal syndrome than continuous delivery, and did so at a lower dose threshold and with greater persistence after forced abstinence.
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Affiliation(s)
- Julia K Brynildsen
- Neuroimaging Research Branch, National Institute on Drug Abuse, Intramural Research Program, 251 Bayview Blvd., Suite 200, Baltimore, MD, USA
| | - Julie Najar
- Neuroimaging Research Branch, National Institute on Drug Abuse, Intramural Research Program, 251 Bayview Blvd., Suite 200, Baltimore, MD, USA
| | - Li-Ming Hsu
- Neuroimaging Research Branch, National Institute on Drug Abuse, Intramural Research Program, 251 Bayview Blvd., Suite 200, Baltimore, MD, USA
| | - D Bruce Vaupel
- Neuroimaging Research Branch, National Institute on Drug Abuse, Intramural Research Program, 251 Bayview Blvd., Suite 200, Baltimore, MD, USA
| | - Hanbing Lu
- Neuroimaging Research Branch, National Institute on Drug Abuse, Intramural Research Program, 251 Bayview Blvd., Suite 200, Baltimore, MD, USA
| | - Thomas J Ross
- Neuroimaging Research Branch, National Institute on Drug Abuse, Intramural Research Program, 251 Bayview Blvd., Suite 200, Baltimore, MD, USA
| | - Yihong Yang
- Neuroimaging Research Branch, National Institute on Drug Abuse, Intramural Research Program, 251 Bayview Blvd., Suite 200, Baltimore, MD, USA
| | - Elliot A Stein
- Neuroimaging Research Branch, National Institute on Drug Abuse, Intramural Research Program, 251 Bayview Blvd., Suite 200, Baltimore, MD, USA.
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Locker AR, Marks MJ, Kamens HM, Klein LC. Exposure to nicotine increases nicotinic acetylcholine receptor density in the reward pathway and binge ethanol consumption in C57BL/6J adolescent female mice. Brain Res Bull 2015; 123:13-22. [PMID: 26428091 DOI: 10.1016/j.brainresbull.2015.09.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Revised: 09/23/2015] [Accepted: 09/24/2015] [Indexed: 10/23/2022]
Abstract
Nearly 80% of adult smokers begin smoking during adolescence. Binge alcohol consumption is also common during adolescence. Past studies report that nicotine and ethanol activate dopamine neurons in the reward pathway and may increase synaptic levels of dopamine in the nucleus accumbens through nicotinic acetylcholine receptor (nAChR) stimulation. Activation of the reward pathway during adolescence through drug use may produce neural alterations affecting subsequent drug consumption. Consequently, the effect of nicotine exposure on binge alcohol consumption was examined along with an assessment of the neurobiological underpinnings that drive adolescent use of these drugs. Adolescent C57BL/6J mice (postnatal days 35-44) were exposed to either water or nicotine (200μg/ml) for ten days. On the final four days, ethanol intake was examined using the drinking-in-the-dark paradigm. Nicotine-exposed mice consumed significantly more ethanol and displayed higher blood ethanol concentrations than did control mice. Autoradiographic analysis of nAChR density revealed higher epibatidine binding in frontal cortical regions in mice exposed to nicotine and ethanol compared to mice exposed to ethanol only. These data show that nicotine exposure during adolescence increases subsequent binge ethanol consumption, and may affect the number of nAChRs in regions of the brain reward pathway, specifically the frontal cortex.
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Affiliation(s)
- Alicia R Locker
- Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Morgantown, WV 26505, United States; The Pennsylvania State University, Department of Biobehavioral Health, University Park, PA 16802, United States.
| | - Michael J Marks
- University of Colorado Boulder, Institute for Behavioral Genetics and Department of Psychology and Neuroscience, Boulder, CO 80303, United States
| | - Helen M Kamens
- The Pennsylvania State University, Department of Biobehavioral Health, University Park, PA 16802, United States
| | - Laura Cousino Klein
- The Pennsylvania State University, Department of Biobehavioral Health, University Park, PA 16802, United States
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18
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Grebenstein PE, Thompson IE, Rowland NE. The effects of extended intravenous nicotine administration on body weight and meal patterns in male Sprague-Dawley rats. Psychopharmacology (Berl) 2013; 228:359-66. [PMID: 23494231 PMCID: PMC3707949 DOI: 10.1007/s00213-013-3043-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Accepted: 02/17/2013] [Indexed: 01/21/2023]
Abstract
RATIONALE Increased appetite and weight gain after cessation is a deterrent for quitting smoking. Attempts to understand the mechanism for these effects using animals have been hampered by the difficulty or inconsistency of modeling the effects seen in humans. OBJECTIVE To examine the effects of extended daily access to intravenous nicotine, via programmed infusions, on body weight and meal patterns in rats. METHODS Intravenous (IV) nicotine infusions (0.06 mg/kg/inf) were administered noncontingently, every 30 min throughout the dark cycle and the last 3 h of the light cycle, to emulate self-administration. The effect of these infusions on food intake, meal patterns, and weight change were examined relative to a control group during treatment and in a post-nicotine phase. RESULTS Nicotine-treated rats gained half the weight that vehicle treated animals gained and ate approximately 20 % less food overall than vehicle-treated rats. Whereas a compensatory increase in meal frequency occurred during the dark period to account for smaller meals, no compensation was observed throughout the light period. In a post-nicotine phase, the nicotine group maintained a lower weight for 1 week and then gained weight back to control levels. The rate of weight gain post-cessation was faster in animals that had received nicotine compared to controls. CONCLUSION Compared to previous studies examining the effects of minipump or intraperitoneal injections of nicotine on food intake, the present study was able to detect previously unknown circadian differences in meal patterns which will be important in the development of smoking cessation and weight gain prevention drugs.
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The volitional nature of nicotine exposure alters anandamide and oleoylethanolamide levels in the ventral tegmental area. Neuropsychopharmacology 2013; 38:574-84. [PMID: 23169348 PMCID: PMC3572454 DOI: 10.1038/npp.2012.210] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Cannabinoid-1 receptors (CB(1)) have an important role in nicotine reward and their function is disrupted by chronic nicotine exposure, suggesting nicotine-induced alterations in endocannabinoid (eCB) signaling. However, the effects of nicotine on brain eCB levels have not been rigorously evaluated. Volitional intake of nicotine produces physiological and behavioral effects distinct from forced drug administration, although the mechanisms underlying these effects are not known. This study compared the effects of volitional nicotine self-administration (SA) and forced nicotine exposure (yoked administration (YA)) on levels of eCBs and related neuroactive lipids in the ventral tegmental area (VTA) and other brain regions. Brain lipid levels were indexed both by in vivo microdialysis in the VTA and lipid extractions from brain tissues. Nicotine SA, but not YA, reduced baseline VTA dialysate oleoylethanolamide (OEA) levels relative to nicotine-naïve controls, and increased anandamide (AEA) release during nicotine intake. In contrast, all nicotine exposure paradigms increased VTA dialysate 2-arachidonoyl glycerol (2-AG) levels. Thus, nicotine differentially modulates brain lipid (2-AG, AEA, and OEA) signaling, and these modulations are influenced by the volitional nature of the drug exposure. Corresponding bulk tissue analysis failed to identify these lipid changes. Nicotine exposure had no effect on fatty acid amide hydrolase activity in the VTA, suggesting that changes in AEA and OEA signaling result from alterations in their nicotine-induced biosynthesis. Both CB(1) (by AEA and 2-AG) and non-CB(1) (by OEA) targets can alter the excitability and activity of the dopaminergic neurons in the VTA. Collectively, these findings implicate disrupted lipid signaling in the motivational effects of nicotine.
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20
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Anderson SM, Brunzell DH. Low dose nicotine and antagonism of β2 subunit containing nicotinic acetylcholine receptors have similar effects on affective behavior in mice. PLoS One 2012; 7:e48665. [PMID: 23144922 PMCID: PMC3492489 DOI: 10.1371/journal.pone.0048665] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Accepted: 09/28/2012] [Indexed: 12/19/2022] Open
Abstract
Nicotine leads to both activation and desensitization (inactivation) of nicotinic acetylcholine receptors (nAChRs). This study tested the hypothesis that nicotine and a selective antagonist of β2*nAChRs would have similar effects on affective behavior. Adult C57BL/6J male mice were tested in a conditioned emotional response (CER) assay which evaluates the ability of an aversive stimulus to inhibit goal-directed behavior. Mice lever-pressed for a saccharin reinforcer according to a variable schedule of reinforcement during sessions in which two presentations of a compound light/tone conditioned stimulus (CS) co-terminated with a 0.1 or 0.3 mA, 0.5 s footshock unconditioned stimulus (US). During testing in the absence of the US, mice received doses of i.p. nicotine (0, 0.0032, 0.01, 0.032, 0.1 mg/kg) or a selective β2 subunit containing nAChR (β2*nAChR) antagonist dihydro-beta-erythroidine (0, 0.1, 0.3, 1.0, 3.0 mg/kg DHβE). There was a dose-dependent effect of nicotine revealing that only low doses (0.01, 0.032 mg/kg) increased CER suppression ratios (SR) in these mice. DHβE also dose-dependently increased SR at the 3 mg/kg dose. In ethological measures of fear-/anxiety-like behavior, these doses of nicotine and DHβE significantly reduced digging behavior in a marble burying task and 0.3 mg/kg DHβE promoted open-arm activity in the elevated plus maze. Doses of nicotine and DHβE that altered affective behavior had no effect on locomotor activity. Similar to previous reports with anxiolytic drugs, low dose nicotine and DHβE reversed SR in a CER assay, decreased digging in a marble burying assay and increased open arm activity in the elevated plus maze. This study provides evidence that inactivation of β2*nAChRs reduces fear-like and anxiety-like behavior in rodents and suggests that smokers may be motivated to smoke in part to desensitize their β2*nAChRs. These data further identify β2*nAChR antagonism as a potential therapeutic strategy for relief of negative affect and anxiety.
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Affiliation(s)
- Shawn M. Anderson
- Department of Pharmacology and Toxicology, Virginia Commonwealth University School of Medicine, Richmond, Virginia, United States of America
| | - Darlene H. Brunzell
- Department of Pharmacology and Toxicology, Virginia Commonwealth University School of Medicine, Richmond, Virginia, United States of America
- Interdepartmental Neuroscience Graduate Program, and Institute for Drug and Alcohol Studies, Virginia Commonwealth University School of Medicine, Richmond, Virginia, United States of America
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21
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Bruijnzeel AW. Tobacco addiction and the dysregulation of brain stress systems. Neurosci Biobehav Rev 2012; 36:1418-41. [PMID: 22405889 PMCID: PMC3340450 DOI: 10.1016/j.neubiorev.2012.02.015] [Citation(s) in RCA: 116] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2011] [Revised: 02/01/2012] [Accepted: 02/23/2012] [Indexed: 11/15/2022]
Abstract
Tobacco is a highly addictive drug and is one of the most widely abused drugs in the world. The first part of this review explores the role of stressors and stress-associated psychiatric disorders in the initiation of smoking, the maintenance of smoking, and relapse after a period of abstinence. The reviewed studies indicate that stressors facilitate the initiation of smoking, decrease the motivation to quit, and increase the risk for relapse. Furthermore, people with depression or an anxiety disorder are more likely to smoke than people without these disorders. The second part of this review describes animal studies that investigated the role of brain stress systems in nicotine addiction. These studies indicate that corticotropin-releasing factor, Neuropeptide Y, the hypocretins, and norepinephrine play a pivotal role in nicotine addiction. In conclusion, the reviewed studies indicate that smoking briefly decreases subjective stress levels but also leads to a further dysregulation of brain stress systems. Drugs that decrease the activity of brain stress systems may diminish nicotine withdrawal and improve smoking cessation rates.
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Affiliation(s)
- Adrie W Bruijnzeel
- Department of Psychiatry, McKnight Brain Institute, University of Florida, 1149 S. Newell Dr., Gainesville, FL 32611, USA.
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22
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Leão RM, Cruz FC, Marin MT, Planeta CDS. Stress induces behavioral sensitization, increases nicotine-seeking behavior and leads to a decrease of CREB in the nucleus accumbens. Pharmacol Biochem Behav 2012; 101:434-42. [PMID: 22330674 DOI: 10.1016/j.pbb.2012.01.025] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2011] [Revised: 01/26/2012] [Accepted: 01/30/2012] [Indexed: 12/17/2022]
Abstract
Experimental evidence shows that exposure to stress engenders behavioral sensitization and increases drug-seeking and leads to intense drug taking. However the molecular mechanisms involved in these processes is not well known yet. The present experiments examined the effects of exposure to variable stress on nicotine-induced locomotor activation, cAMP-response element-binding protein (CREB) and extracellular signal-regulated kinase (ERK) activity and nicotine intravenous self-administration in rats. Male Wistar rats were exposed to variable stress that consisted of the exposure to different stressors twice a day in random order for 10 days. During this period the control group was left undisturbed except for cage cleaning. Ten days after the last stress episode, rats were challenged with either saline or nicotine (0.4 mg/kgs.c.) and the locomotor activity was recorded for 20 min. Immediately after behavioral recordings rats were sacrificed and their brains were removed to posterior western blotting analysis of CREB, phosphoCREB, ERK and phosphoERK in the nucleus accumbens. An independent set of control and stressed animals were subjected to an intravenous nicotine self-administration protocol. The break point during a progressive ratio schedule and nicotine intake patterns during a 24-hour binge was analyzed. Repeated variable stress caused a sensitized motor response to a single challenge of nicotine and decreased CREB in the nucleus accumbens. Furthermore, in the self-administration experiments previous stress exposure caused an increase in the break point and nicotine intake.
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Affiliation(s)
- Rodrigo Molini Leão
- Laboratory of Pharmacology, School of Pharmaceutical Sciences, Univ. Estadual Paulista-UNESP, Rod. Araraquara-Jaú Km 1, 14801-902, Araraquara, São Paulo, Brazil
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23
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Lutfy K, Aimiuwu O, Mangubat M, Shin CS, Nerio N, Gomez R, Liu Y, Friedman TC. Nicotine stimulates secretion of corticosterone via both CRH and AVP receptors. J Neurochem 2012; 120:1108-16. [PMID: 22191943 DOI: 10.1111/j.1471-4159.2011.07633.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Corticosterone-releasing hormone (CRH) and arginine vasopressin (AVP) are crucial components of the hypothalamic-pituitary-adrenal axis that stimulates the release of adrenocorticotropic hormone from the pituitary and mediate the stress response. CRH binds to two subtypes of CRH receptors (CRH-R1 and CRH-R2) that are present in both central and peripheral tissues. We used the CRH-R1-specific antagonist, antalarmin (ANT), the CRH-R1 and CRH-R2 peptide antagonist, astressin (AST), and the CRH-R2-specific peptide antagonist, astressin2b (AST2b), to determine which CRH receptor is involved in the nicotine-stimulated secretion of corticosterone. Male C57BL/6 mice were administered ANT (20 mg/kg, i.p.), AST (0.3 mg/kg, i.p.), AST2b (0.3 mg/kg, i.p.) or vehicle prior to administration of nicotine (1.0 mg/kg, s.c.), CRH (10 μg/kg, s.c.), AVP (10 μg/kg, s.c.) or saline (s.c.), killed 15 min later and trunk blood collected and assayed for corticosterone plasma levels. We found that CRH enhanced corticosterone release, and this response was blocked by both AST and ANT. Nicotine also increased corticosterone secretion, but this effect persisted in the presence of either CRH antagonist. Furthermore, AST but not ANT or AST2b decreased corticosterone levels associated with stress of handling and injection. We also assessed the role of AVP V(1b) -specific receptor antagonist, SSR149415 alone and in combination with AST and AST2b. Although the AVP antagonist did not alter basal or nicotine-stimulated corticosterone secretion, it attenuated the AVP-induced stimulation of corticosterone and its combination with AST but not AST2b completely abolished nicotine-mediated stimulation of corticosterone secretion. Our results demonstrate that the nicotine-induced stimulation of the hypothalamic-pituitary-adrenal axis is mediated by both the CRH-R and the AVP V(1b) receptor and when the CRH receptor is blocked, nicotine may utilize the AVP V(1b) receptor to mediate secretion of corticosterone. These results argue in favor of the development of specific antagonists that block both AVP and CRH receptors to decrease the pleasurable component of nicotine, which may be mediated by corticosterone.
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Affiliation(s)
- Kabirullah Lutfy
- Division of Endocrinology, Molecular Medicine and Metabolism, Department of Internal Medicine, Charles R. Drew University of Medicine & Sciences-David Geffen School of Medicine at UCLA, Los Angeles, California, USA
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24
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Frenk H, Dar R. If the data contradict the theory, throw out the data: Nicotine addiction in the 2010 report of the Surgeon General. Harm Reduct J 2011; 8:12. [PMID: 21595895 PMCID: PMC3116468 DOI: 10.1186/1477-7517-8-12] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2011] [Accepted: 05/19/2011] [Indexed: 11/30/2022] Open
Abstract
The reports of US Surgeon General on smoking are considered the authoritative statement on the scientific state of the art in this field. The previous report on nicotine addiction published in 1988 is one of the most cited references in scientific articles on smoking and often the only citation provided for specific statements of facts regarding nicotine addiction. In this commentary we review the chapter on nicotine addiction presented in the recent report of the Surgeon General. We show that the nicotine addiction model presented in this chapter, which closely resembles its 22 years old predecessor, could only be sustained by systematically ignoring all contradictory evidence. As a result, the present SG's chapter on nicotine addiction, which purportedly "documents how nicotine compares with heroin and cocaine in its hold on users and its effects on the brain," is remarkably biased and misleading.
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Affiliation(s)
- Hanan Frenk
- Department of Psychology, Tel Aviv University, Ramat Aviv 69978, Israel.
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25
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Donny EC, Caggiula AR, Weaver MT, Levin ME, Sved AF. The reinforcement-enhancing effects of nicotine: implications for the relationship between smoking, eating and weight. Physiol Behav 2011; 104:143-8. [PMID: 21549139 DOI: 10.1016/j.physbeh.2011.04.043] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2011] [Revised: 04/22/2011] [Accepted: 04/26/2011] [Indexed: 01/19/2023]
Abstract
Concerns about body weight represent an important barrier to public health efforts aimed at reducing smoking. Epidemiological studies have found that current smokers weigh less than non-smokers, smoking cessation results in weight gain, and weight restriction is commonly cited as a reason for smoking. The mechanisms underlying the relationship between smoking and weight are complex and may involve a number of factors including changes in caloric intake, physical activity, metabolic rate, and lipogenesis. Amongst these possible mechanisms, nicotine-induced enhancement of food reinforcement may be particularly important. In this paper, we first review data from our laboratory that highlight two distinct ways in which nicotine impacts reinforced behavior: 1) by acting as a primary reinforcer; and 2) by directly (non-associatively) enhancing the reinforcing effects of other stimuli. We then elaborate on the reinforcement-enhancing effects of nicotine as they pertain to behaviors and stimuli related to food. Data from both laboratory animals and humans support the assertion that nicotine enhances the reinforcing efficacy of food and suggest that the influence of these effects on eating may be most important after nicotine cessation when nicotine's effects on satiety subside. Finally, we discuss the theoretical and clinical implications of this perspective for understanding and addressing the apparent tradeoff between smoking and weight gain. Better understanding of the mechanisms underlying the reinforcement-enhancing effects of nicotine broadly, and the effects on food reinforcement per se, may aid in the development of new treatments with better long term outcomes.
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Affiliation(s)
- Eric C Donny
- Department of Psychology, University of Pittsburgh, 210 S. Bouquet Street, Pittsburgh, PA 15260, USA.
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26
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Donny EC, Caggiula AR, Sweitzer M, Chaudhri N, Gharib M, Sved AF. Self-administered and yoked nicotine produce robust increases in blood pressure and changes in heart rate with modest effects of behavioral contingency in rats. Pharmacol Biochem Behav 2011; 99:459-67. [PMID: 21554897 DOI: 10.1016/j.pbb.2011.04.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2011] [Revised: 03/29/2011] [Accepted: 04/21/2011] [Indexed: 11/28/2022]
Abstract
Experimenter-administered nicotine produces reliable increases in blood pressure and changes in heart rate. However, an extensive literature demonstrates that the effects of psychoactive drugs are dependent on whether administration is contingent on behavior. The present study assessed the cardiovascular effects of nicotine and whether those effects vary as a function of whether nicotine was self-administered or response-independent. Rats were divided into three groups according to a yoked design. The pattern of infusions for each triad was determined by the animal self-administering nicotine; the other two animals received either yoked nicotine or saline. Heart rate and blood pressure were measured during eighteen daily, 1h drug sessions by radiotelemetry. Each session was preceded and followed by a 20 minute period during which cardiovascular function was monitored in the operant chambers, but drug was not available. Acute exposure to yoked nicotine produced a rapid rise in blood pressure that was larger than the increase observed with self-administered nicotine. Additional infusions during the first session resulted in a similar sustained elevation in blood pressure in the nicotine groups. Over subsequent sessions, self-administered nicotine produced a larger effect on systolic blood pressure particularly early in each session, although for both self-administered and yoked nicotine the hypertensive effects waned partially with repeated test sessions. This decrease was fully accounted for by a pre-session decrease in pressure; relative to pre-session levels the strong hypertensive effects of nicotine persisted. Initial exposure to nicotine produced a short-lived bradycardia that in subsequent sessions was replaced with a longer-lasting nicotine-induced tachycardia; neither effect was related to the behavioral contingency of nicotine delivery. Together, these data provide a rich picture of the cardiovascular effects of nicotine. Effects of behavioral contingency were observed, but differences were limited. Other non-pharmacological factors such as baseline shifts potentially related to nicotine-associated cues deserve further attention.
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Affiliation(s)
- Eric C Donny
- Department of Psychology, University of Pittsburgh, 210 S. Bouquet Street, Pittsburgh, PA 15260, USA.
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27
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Paterson NE. Translational research in addiction: toward a framework for the development of novel therapeutics. Biochem Pharmacol 2011; 81:1388-407. [PMID: 21216239 DOI: 10.1016/j.bcp.2010.12.017] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2010] [Revised: 12/13/2010] [Accepted: 12/15/2010] [Indexed: 12/16/2022]
Abstract
The development of novel substance use disorder (SUD) therapeutics is insufficient to meet the medical needs of a growing SUD patient population. The identification of translatable SUD models and tests is a crucial step in establishing a framework for SUD therapeutic development programs. The present review begins by identifying the clinical features of SUDs and highlights the narrow regulatory end-point required for approval of a novel SUD therapeutic. A conceptual overview of dependence is provided, followed by identification of potential intervention targets in the addiction cycle. The main components of the addiction cycle provide the framework for a discussion of preclinical models and their clinical analogs, all of which are focused on isolated behavioral end-points thought to be relevant to the persistence of compulsive drug use. Thus, the greatest obstacle to successful development is the gap between the multiplicity of preclinical and early clinical end-points and the regulatory end-point of sustained abstinence. This review proposes two pathways to bridging this gap: further development and validation of the preclinical extended access self-administration model; inclusion of secondary end-points comprising all of the measures highlighted in the present discussion in Phase 3 trials. Further, completion of the postdictive validation of analogous preclinical and clinical assays is of high priority. Ultimately, demonstration of the relevance and validity of a variety of end-points to the ultimate goal of abstinence will allow researchers to identify truly relevant therapeutic mechanisms and intervention targets, and establish a framework for SUD therapeutic development that allows optimal decision-making and resource allocation.
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Affiliation(s)
- Neil E Paterson
- Behavioral Pharmacology, PsychoGenics, Inc., 765 Old Saw Mill River Rd., Tarrytown, NY 10591, USA.
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Metaxas A, Bailey A, Barbano MF, Galeote L, Maldonado R, Kitchen I. Differential region-specific regulation of α4β2* nAChRs by self-administered and non-contingent nicotine in C57BL/6J mice. Addict Biol 2010; 15:464-79. [PMID: 20731631 DOI: 10.1111/j.1369-1600.2010.00246.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Neuronal nAChR upregulation is the hallmark of chronic nicotine exposure. Neuroplasticity to abused drugs, however, depends on whether their administration is forced by the experimenter or is under the control of the experimental animal. Neuroadaptation to chronic nicotine self-administration was examined with a yoked-control paradigm, using nose-poking as the operating procedure. Freely moving C57BL/6J mice that responded for 0.03 mg/kg/infusion of intravenous nicotine under a continuous schedule of reinforcement (FR-1), had control over the rate and amount of drug intake that a yoked littermate passively received (n = 11). The impact of response dependency on neurobiological changes in nicotinic and dopaminergic systems was subsequently assessed using quantitative autoradiography. Cytisine-sensitive [(125)I]epibatidine binding, [³H]SCH23390, [³H]raclopride and [³H]mazindol were used to label nAChRs with α4β2* subtype properties, D1 and D2 dopaminergic receptors, and dopamine transporters, respectively. During a period of 12 days, self-administration was reliably initiated and maintained in animals receiving response-contingent nicotine. Region specific changes in the density of α4β2* nAChRs were found to be dependent on the contingency of nicotine treatment. Higher levels of α4β2* receptor binding were observed in the dorsal lateral geniculate nucleus and the ventral tegmental area of self-administering mice, compared to non-contingent animals. Moreover, response-independent increases in D2 binding were observed following chronic nicotine administration. No change in D1 and DAT binding was observed among groups. These findings indicate regional specific alterations in the regulation of the nicotinic cholinergic system following contingent and non-contingent nicotine exposure, and underline the importance of response dependency on the development of nicotine addiction.
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Affiliation(s)
- Athanasios Metaxas
- Faculty of Health & Medical Sciences, Division of Biochemical Sciences, University of Surrey, UK.
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Abstract
Tobacco use became common all over the world after discovery of Americas. Tobacco, a plant carries in its leaves an alkaloid called nicotine, which is responsible not only for several pathophysiological changes in the body but also develops tolerance to its own action with repeated use. Studies suggest that the alpha-4 beta-2 nicotine acetylcholine receptor subtype is the main receptor that mediates nicotine dependence. Nicotine acts on these receptors to facilitate neurotransmitter release (dopamine and others), producing pleasure and mood modulation. Repeated exposure to nicotine develops neuroadaptation of the receptors, resulting in tolerance to many of the effects of nicotine. Withdrawal symptoms appear on stoppage of tobacco use, which are characterized by irritability, anxiety, increased eating, dysphoria, and hedonic dysregulation, among others. Smoking is also reinforced by conditioning. Pharmacotherapies for smoking cessation should reduce withdrawal symptoms and block the reinforcing effects of nicotine obtained from smoking without causing excessive adverse effects.
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Affiliation(s)
- R C Jiloha
- Department of Psychiatry, G. B. Pant Hospital, Maulana Azad Medical College and University of Delhi, India
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Armario A. Activation of the hypothalamic-pituitary-adrenal axis by addictive drugs: different pathways, common outcome. Trends Pharmacol Sci 2010; 31:318-25. [PMID: 20537734 DOI: 10.1016/j.tips.2010.04.005] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2010] [Revised: 04/22/2010] [Accepted: 04/22/2010] [Indexed: 01/20/2023]
Abstract
Addictive drugs (opiates, ethanol, cannabinoids (CBs), nicotine, cocaine, amphetamines) induce activation of the hypothalamic-pituitary-adrenal (HPA) axis, with the subsequent release of adrenocorticotropic hormone and glucocorticoids. The sequence of events leading to HPA activation appears to start within the brain, suggesting that activation is not secondary to peripheral homeostatic alterations. The precise neurochemical mechanisms and brain pathways involved are markedly dependent on the particular drug, although it is assumed that information eventually converges into the hypothalamic paraventricular nucleus (PVN). Whereas some drugs may act on the hypothalamus or directly within PVN neurons (i.e. ethanol), others exert their primary action outside the PVN (i.e. CBs, nicotine, cocaine). Corticotropin-releasing hormone (CRH) has a critical role in most cases, but the changes in c-fos and CRH gene expression in the PVN also reveal differences among drugs. More studies are needed to understand how addictive drugs act on this important neuroendocrine system and their functional consequences.
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Affiliation(s)
- Antonio Armario
- Institute of Neurosciences and Animal Physiology Unit (Department of Cellular Biology, Physiology and Immunology), Autonomous University of Barcelona, 08193 Bellaterra, Barcelona, Spain.
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Lê A, Lo S, Harding S, Juzytsch W, Marinelli PW, Funk D. Coadministration of intravenous nicotine and oral alcohol in rats. Psychopharmacology (Berl) 2010; 208:475-86. [PMID: 20013113 PMCID: PMC2977987 DOI: 10.1007/s00213-009-1746-6] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2009] [Accepted: 11/26/2009] [Indexed: 10/20/2022]
Abstract
RATIONALE AND OBJECTIVES Alcohol and nicotine are the most commonly abused drugs, and they are often taken together. We have developed a procedure in which rats self-administer nicotine intravenously and alcohol orally during the same operant session. METHODS Male Wistar rats were trained to self-administer alcohol (12%, w/v; 0.19 ml/alcohol delivery) or implanted with jugular catheters and trained to self-administer nicotine (30 microg/kg i.v./infusion) by pressing a lever or were trained to self-administer both drugs, some with alcohol first, and others with nicotine first. The effects of extinction of responding for either or both drugs in animals trained to coadminister alcohol and nicotine and the effects of alcohol and nicotine primes on reinstatement were also determined. RESULTS Animals readily coadministered alcohol and nicotine concurrently. Access to alcohol reduced nicotine self-administration significantly. When responding for alcohol was extinguished with nicotine still available, extinction of alcohol seeking was slowed significantly. In rats trained to coadminister nicotine and alcohol, priming with nicotine or alcohol reinstated extinguished responding for both drugs. Reinstatement of extinguished nicotine or alcohol seeking by, respectively, nicotine or alcohol priming was unaffected by continued access to the other drug. CONCLUSIONS These results show that rats will self-administer relevant amounts of intravenous nicotine and oral alcohol concurrently. They also provide further support for the important relationship between nicotine and alcohol.
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Affiliation(s)
- A.D. Lê
- Neuroscience Department, Centre for Addiction and Mental Health, Toronto, Canada,Department of Pharmacology, University of Toronto,Department of Psychiatry, University of Toronto
| | - Steven Lo
- Neuroscience Department, Centre for Addiction and Mental Health, Toronto, Canada,Department of Pharmacology, University of Toronto
| | - Stephen Harding
- Neuroscience Department, Centre for Addiction and Mental Health, Toronto, Canada
| | - Walter Juzytsch
- Neuroscience Department, Centre for Addiction and Mental Health, Toronto, Canada
| | - Peter W. Marinelli
- Neuroscience Department, Centre for Addiction and Mental Health, Toronto, Canada
| | - Douglas Funk
- Neuroscience Department, Centre for Addiction and Mental Health, Toronto, Canada
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Shram MJ, Lê AD. Adolescent male Wistar rats are more responsive than adult rats to the conditioned rewarding effects of intravenously administered nicotine in the place conditioning procedure. Behav Brain Res 2009; 206:240-4. [PMID: 19765617 DOI: 10.1016/j.bbr.2009.09.018] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2009] [Revised: 09/09/2009] [Accepted: 09/11/2009] [Indexed: 10/20/2022]
Abstract
The initiation of smoking typically begins during adolescence, suggesting that nicotine may have different motivational effects during this developmental stage compared to adulthood. Studies using the conditioned place preference (CPP) procedure have demonstrated that adolescent rats are more sensitive to the conditioned rewarding effects of subcutaneously administered nicotine compared to adult rats, whereas intravenous self-administration studies have not demonstrated consistent age differences in the reinforcing effects of nicotine. This study was designed to evaluate if intravenously administered nicotine has age-dependent conditioned rewarding effects. Using an unbiased CPP procedure, adolescent and adult male Wistar rats were conditioned with one of two intravenous doses of nicotine that are sufficient to maintain self-administration (0.03 or 0.06 mg/kg) or vehicle (saline) over a period of 8 conditioning trials (4 nicotine and 4 vehicle). Adolescent rats conditioned with 0.03 mg/kg nicotine demonstrated a significant CPP, whereas adult rats did not at either dose tested. After 8 extinction trials, reinstatement of the CPP was observed following a nicotine priming injection (0.15 mg/kg, s.c.) in adolescents that had previously been conditioned with 0.03 mg/kg nicotine; vehicle-treated rats did not show a significant preference for either compartment. The present data are consistent with previous CPP studies using subcutaneously administered nicotine and suggest that passively administered intravenous nicotine is more rewarding in adolescent compared to adult rats.
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Affiliation(s)
- Megan J Shram
- Department of Neuroscience, Centre for Addiction and Mental Health, Toronto, Ontario, Canada M5S 2S1.
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33
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Abstract
The survival and well-being of all species requires appropriate physiological responses to environmental and homeostatic challenges. The re- establishment and maintenance of homeostasis entails the coordinated activation and control of neuroendocrine and autonomic stress systems. These collective stress responses are mediated by largely overlapping circuits in the limbic forebrain, the hypothalamus and the brainstem, so that the respective contributions of the neuroendocrine and autonomic systems are tuned in accordance with stressor modality and intensity. Limbic regions that are responsible for regulating stress responses intersect with circuits that are responsible for memory and reward, providing a means to tailor the stress response with respect to prior experience and anticipated outcomes.
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Paterson NE. Behavioural and pharmacological mechanisms of bupropion's anti-smoking effects: recent preclinical and clinical insights. Eur J Pharmacol 2008; 603:1-11. [PMID: 19101536 DOI: 10.1016/j.ejphar.2008.12.009] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2008] [Revised: 11/23/2008] [Accepted: 12/09/2008] [Indexed: 11/28/2022]
Abstract
Ongoing studies continue to explore the behavioural and pharmacological effects of bupropion in smoking cessation studies and animal models of nicotine dependence. In the present review, the components of nicotine dependence that form the most likely targets of bupropion are identified within the context of an expanding preclinical and clinical literature regarding the anti-addictive properties of bupropion. Second, preclinical and clinical data that implicate specific pharmacological modes of action of bupropion in mediating the anti-smoking effects of the compound are discussed. Third, it is suggested that the unique mixed pharmacological profile of bupropion provides (1) attenuation of the multiple negative consequences of withdrawal via blockade of dopamine and noradrenaline reuptake; (2) replacement of the reward-facilitating and subjective effects of nicotine via blockade of dopaminergic reuptake; (3) attenuation of the rewarding effects of acute nicotine by nicotinic acetylcholine receptor blockade. The importance of species differences in bupropion metabolism in the interpretation of preclinical studies is highlighted. Finally, future studies are suggested to address identified gaps in the knowledge: most importantly, to provide stronger evidence for the role of noradrenaline reuptake inhibition in bupropion-induced attenuation of nicotine withdrawal. Future studies aimed at providing more evidence for the three-fold nature of the anti-smoking effects of bupropion are also suggested, along with the possibility of utilizing adjunct therapies to improve smoking cessation rates.
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Affiliation(s)
- Neil E Paterson
- Behavioural Pharmacology, PsychoGenics, Inc, Tarrytown, NY 10591, USA.
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35
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Chen H, Fu Y, Sharp BM. Chronic nicotine self-administration augments hypothalamic-pituitary-adrenal responses to mild acute stress. Neuropsychopharmacology 2008; 33:721-30. [PMID: 17551542 DOI: 10.1038/sj.npp.1301466] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
We investigated the effect of chronic nicotine self-administration (SA) on hypothalamic-pituitary-adrenal (HPA) hormonal responses to acute stressors. Adult male Sprague-Dawley rats were given access to nicotine (0.03 mg/kg) for 23 h per day for 20 days. On day 1 of acquisition of nicotine SA, plasma levels of both adrenocorticotropin and corticosterone were significantly increased 15-30 min after the first dose of nicotine. These hormonal changes were no longer significant on day 3, when adrenocorticotropin levels were <60 pg/ml and corticosterone levels were <110 ng/ml during the hour after the first dose of nicotine. Chronic nicotine SA (20 days) significantly augmented (2-3-fold) both hormonal responses to mild foot shock stress (0.6 mA, 0.5 s per shock, 5 shocks per 5 min), but did not affect hormonal responses to moderate shock (1.2 mA, 0.5 s per shock, 5 shocks per 5 min), lipopolysaccharide or immobilization. Similar data were obtained in Lewis rats. These results provide further support for the concept that chronic nicotine SA is a stressor. In alignment with the effects of other stressors, nicotine activated the HPA axis on the first day of SA, but desensitization occurred with repeated exposure. Furthermore, chronic nicotine SA selectively cross-sensitized the HPA response to a novel stressor. These observations suggest that nicotine may selectively increase the HPA response to stressors in human smokers.
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Affiliation(s)
- Hao Chen
- Department of Pharmacology, University of Tennessee Health Science Center, Memphis, TN 38163, USA
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36
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The role of nicotine in smoking: a dual-reinforcement model. NEBRASKA SYMPOSIUM ON MOTIVATION. NEBRASKA SYMPOSIUM ON MOTIVATION 2008; 55:91-109. [PMID: 19013940 DOI: 10.1007/978-0-387-78748-0_6] [Citation(s) in RCA: 165] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
Models of intravenous nicotine self-administration in laboratory animals are being used to investigate the behavioral and neurobiological consequences of nicotine reinforcement, and to aid in the development of novel pharmacotherapies for smoking cessation. Central to these models is the principle of primary reinforcement, which posits that response-contingent presentation of a primary reinforcer, nicotine, engenders robust operant behavior, whereas response-independent drug delivery does not. This dictum of nicotine as a primary reinforcer has been widely used to explain why people smoke tobacco-smoking results in the rapid delivery of nicotine to the brain, setting up a cascade of neurobiological processes that strengthen subsequent smoking behavior. However, there is mounting evidence that the primary reinforcement model of nicotine self-administration fails to fully explain existing data from both the animal self-administration and human smoking literatures. We have recently proposed a "dual reinforcement" model to more fully capture the relationship between nicotine and self-administration, including smoking. Briefly, the "dual reinforcement" model posits that nicotine acts as both a primary reinforcer and a reinforcement enhancer. The latter action of nicotine had originally been uncovered by showing that a reinforcing VS, which accompanies nicotine delivery, synergizes with nicotine in the acquisition and maintenance of self-administration, and that this synergism can be reproduced by combining operant responding for the reinforcing stimulus with non-contingent (response-independent) nicotine. Thus, self-administration (and smoking) is sustained by three actions: (1) nicotine, acting as a primary reinforcer, can sustain behavior that leads to its delivery; (2) nicotine, acting as a primary reinforcer, can establish neutral environmental stimuli as conditioned reinforcers through Pavlovian associations; and (3) nicotine, acting as a reinforcement enhancer, can magnify the incentive value of accompanying stimuli, be they conditioned or unconditioned reinforcers.
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37
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Lutfy K, Brown MC, Nerio N, Aimiuwu O, Tran B, Anghel A, Friedman TC. Repeated stress alters the ability of nicotine to activate the hypothalamic-pituitary-adrenal axis. J Neurochem 2006; 99:1321-7. [PMID: 17064351 DOI: 10.1111/j.1471-4159.2006.04217.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Acute nicotine administration has been shown to activate the hypothalamic-pituitary-adrenal (HPA) axis and stimulate secretion of adrenocorticotrophic hormone (ACTH), corticosterone/cortisol and beta-endorphin (beta-END) in both rodents and humans, raising the possibility that activation of the HPA axis by nicotine may mediate some of the effects of nicotine. Since stress can increase the risk of drug use and abuse, we hypothesized that repeated stress would increase the ability of nicotine to stimulate the secretion of HPA hormones. To test our hypothesis, mice were exposed to repeated stress (swimming in 15 degrees C water for 3 min/day for 5 days) and killed 15 min after injection of saline or nicotine (0.1 mg/kg, s.c.). Repeated exposure to stress increased the ability of nicotine to stimulate plasma ACTH (p<0.05) and beta-END (p<0.05), but not corticosterone secretion. In contrast, repeated exposure to stress increased the post-saline injection levels of corticosterone (p<0.05), but not ACTH and beta-END. The present results suggest that chronic stress leads to an enhanced sensitivity of some components of the HPA axis to a subsequent nicotine challenge.
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Affiliation(s)
- Kabirullah Lutfy
- Division of Endocrinology, Molecular Medicine and Metabolism, Department of Medicine, Charles R. Drew University of Medicine & Sciences-David Geffen School of Medicine at UCLA, Los Angeles, California 90059, USA
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Donny EC, Bigelow GE, Walsh SL. Comparing the physiological and subjective effects of self-administered vs yoked cocaine in humans. Psychopharmacology (Berl) 2006; 186:544-52. [PMID: 16552557 DOI: 10.1007/s00213-006-0312-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2005] [Accepted: 12/07/2005] [Indexed: 10/24/2022]
Abstract
RATIONALE Studies with laboratory animals demonstrating different effects of self- vs experimenter-administered drug suggest that the ability to control or predict drug delivery may be an important determinant of drug action. OBJECTIVE This study assessed whether self-administered and yoked cocaine injections produce different effects in humans. METHODS Ten inpatient volunteers with experience in using cocaine participated in a double-blind, yoked design during which four experimental test sessions were conducted. During two sessions, participants controlled if and when up to six 40 mg/70 kg i.v. cocaine injections were given. During two sessions, participants received noncontingent exposure to the same pattern of injections given during the preceding session (i.e., yoked) under blind conditions. Sessions followed a fixed-order, ABAB design. Measures of subjective and physiological response to cocaine were taken throughout each session. RESULTS Cardiovascular safety parameters were exceeded in some individuals after yoked, but not self-administered, cocaine resulting in some scheduled injections being delayed or withheld. Mean systolic and diastolic blood pressures were higher following yoked compared to self-administered cocaine. In contrast, analysis of the subjective effects revealed only small and generally nonsignificant differences in the effects of self-administered vs yoked cocaine. CONCLUSIONS These results suggest that under the laboratory methods employed, control over the schedule of drug delivery may not alter the subjective effects of cocaine in humans. In contrast, the cardiovascular effects of cocaine appear to be greater when the drug is administered noncontingently.
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Affiliation(s)
- Eric C Donny
- Department of Psychology, University of Pittsburgh, Pittsburgh, PA, USA.
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39
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De La Garza R. Wistar Kyoto rats exhibit reduced sucrose pellet reinforcement behavior and intravenous nicotine self-administration. Pharmacol Biochem Behav 2005; 82:330-7. [PMID: 16226802 DOI: 10.1016/j.pbb.2005.09.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2005] [Revised: 08/25/2005] [Accepted: 09/07/2005] [Indexed: 10/25/2022]
Abstract
A phenotype of heightened anxiety-like behavior is hypothesized to be associated with altered reinforcement behavior. To test this hypothesis, we studied patterns of sucrose pellet intake and intravenous nicotine self-administration in animals that exhibit anxiety-like behavior at baseline, Wistar Kyoto (WKY) rats, as compared to normal controls (Wistar rats). WKY rats exhibited significantly reduced sucrose pellet self-administration behavior as assessed by both fixed and progressive ratio schedules of reinforcement and exhibited significantly reduced self-administration of intravenous nicotine. On the basis of previously published findings, we hypothesize that altered mesolimbic dopamine responses, as well as heightened HPA axis functioning, may account for reduced nicotine self-administration and sucrose pellet reinforcement responding in WKY rats. These studies highlight the role of heightened anxiety-like behavior, resulting from the genetic background of the animal, in altering behavioral responses to reinforcing stimuli.
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Affiliation(s)
- Richard De La Garza
- David Geffen School of Medicine at the University of California Los Angeles, Department of Psychiatry and Biobehavioral Sciences, Los Angeles, CA 90024, USA.
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40
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Paterson NE, Markou A. The metabotropic glutamate receptor 5 antagonist MPEP decreased break points for nicotine, cocaine and food in rats. Psychopharmacology (Berl) 2005; 179:255-61. [PMID: 15619120 DOI: 10.1007/s00213-004-2070-9] [Citation(s) in RCA: 138] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2004] [Accepted: 10/18/2004] [Indexed: 10/26/2022]
Abstract
RATIONALE The metabotropic glutamate (mGlu5) receptor subtype 5 antagonist MPEP attenuates self-administration of numerous drugs of abuse. OBJECTIVES The purpose of the present study was to explore whether MPEP-induced decreases in nicotine and cocaine self-administration reflect attenuation of the reinforcing and incentive motivational effects of nicotine and cocaine. The effects of MPEP on breaking points maintained by nicotine, cocaine or food were assessed using a progressive ratio schedule of reinforcement. Breaking points obtained under such schedules are postulated to reflect both the reinforcing and incentive motivational properties of reinforcers. METHODS Rats were allowed to respond for nicotine (0.05 mg/kg per infusion, free base), cocaine (0.18 mg/kg per infusion, salt), or food (45 mg pellets) under a progressive ratio schedule of reinforcement. After establishing stable and equivalent levels of responding for all three reinforcers, rats underwent one test session where no rewards were presented to assess the effects of 1-day extinction, similar to 1-day pharmacological-induced extinction, on performance in this schedule. Subsequently, rats were again allowed to respond for nicotine, cocaine or food until reestablishment of stable levels of responding. Then, MPEP (1-9 mg/kg) was administered intraperitoneally according to a within-subjects Latin square design, 30 min prior to the testing sessions. RESULTS Responding in the absence of a primary reinforcer was significantly decreased compared to responding under baseline conditions. Further, MPEP decreased break points maintained by nicotine, cocaine and food. CONCLUSIONS The mGlu5 receptor is implicated in mediating the reinforcing and incentive motivational properties of nicotine, cocaine and food.
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Affiliation(s)
- Neil E Paterson
- Department of Neuropharmacology, CVN-7, The Scripps Research Institute, La Jolla, CA 92037, USA
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41
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Frenk H, Dar R. Reward potentiation or behavioral activation? A comment on Donny et al. Psychopharmacology (Berl) 2004; 171:472-3; author reply 474-6. [PMID: 14566447 DOI: 10.1007/s00213-003-1622-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2003] [Accepted: 08/10/2003] [Indexed: 10/26/2022]
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Rahman S, Zhang J, Engleman EA, Corrigall WA. Neuroadaptive changes in the mesoaccumbens dopamine system after chronic nicotine self-administration: A microdialysis study. Neuroscience 2004; 129:415-24. [PMID: 15501598 DOI: 10.1016/j.neuroscience.2004.08.010] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/13/2004] [Indexed: 11/25/2022]
Abstract
There is little evidence to date to indicate if mesoaccumbens dopamine function at the neurochemical level is altered during early abstinence from chronic i.v. nicotine self-administration. Thus, a quantitative microdialysis (no-net-flux) approach was used to measure basal extracellular concentrations and extraction fractions of dopamine in the nucleus accumbens (ACB) of rats that self-administered nicotine i.v. for 25 days, as well as in rats serving as yoked comparison groups (yoked nicotine and yoked saline). After 24-48 h of the final self-administration session, there was a significant reduction in basal extracellular dopamine levels in the ACB of the self-administration group compared with the yoked saline group (1.35+/-0.15 nM versus 3.70+/-0.28 nM). The basal extracellular dopamine levels in the yoked nicotine group (1.46+/-0.20 nM) were not significantly different compared with the nicotine self-administration group. The in vivo extraction fraction of dopamine, an indirect measure of dopamine uptake, was significantly increased in the nicotine self-administration (86%) and yoked nicotine (91%) groups compared with the yoked saline group (77%). In addition, a marked reduction in the elevation of extracellular dopamine levels in the ACB occurred after a nicotine challenge as measured by conventional microdialysis in the self-administration (112% of basal) and yoked nicotine (121% of basal) groups as compared with a yoked saline (154% of basal) group. The reduced basal ACB dopamine levels in the nicotine groups during early abstinence appears to be due to increased clearance, suggesting increased dopamine uptake is occurring as a result of the chronic nicotine treatment. The reduced elevation of extracellular dopamine levels in the ACB upon nicotine challenge suggests a functional desensitization or downregulation phenomenon involving acetylcholine receptors (nicotinic nAChRs). Overall, these results provide clear evidence for a neuroadaptive change that alters dopamine transmission in the ACB during abstinence from chronic i.v. nicotine exposure.
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Affiliation(s)
- S Rahman
- Smoking and Nicotine Dependence Research, Neuroscience Department, Centre for Addiction and Mental Health, University of Toronto, 33 Russell Street, Toronto, Ontario, M5S 2S1 Canada.
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Rahman S, Zhang J, Engleman E, Corrigall W. Neuroadaptive changes in the mesoaccumbens dopamine system after chronic nicotine self-administration: A microdialysis study. Neuroscience 2004. [DOI: https://doi.org/10.1016/j.neuroscience.2004.08.010] [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]
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Caggiula AR, Donny EC, White AR, Chaudhri N, Booth S, Gharib MA, Hoffman A, Perkins KA, Sved AF. Cue dependency of nicotine self-administration and smoking. Pharmacol Biochem Behav 2001; 70:515-30. [PMID: 11796151 DOI: 10.1016/s0091-3057(01)00676-1] [Citation(s) in RCA: 318] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
A paradox exists regarding the reinforcing properties of nicotine. The abuse liability associated with smoking equals or exceeds that of other addictive drugs, yet the euphoric, reinforcing and other psychological effects of nicotine, compared to these other drugs, are more subtle, are manifest under more restricted conditions, and do not readily predict the difficulty most smokers experience in achieving abstinence. One possible resolution to this apparent inconsistency is that environmental cues associated with drug delivery become conditioned reinforcers and take on powerful incentive properties that are critically important for sustaining smoking in humans and nicotine self-administration in animals. We tested this hypothesis by using a widely employed self-administration paradigm in which rats press a lever at high rates for 1 h/day to obtain intravenous infusions of nicotine that are paired with two types of visual stimuli: a chamber light that when turned on signals drug availability and a 1-s cue light that signals drug delivery. We show that these visual cues are at least as important as nicotine in sustaining a high rate of responding once self-administration has been established, in the degree to which withdrawing nicotine extinguishes the behavior, and in the reinstatement of lever pressing after extinction. Additional studies demonstrated that the importance of these cues was manifest under both fixed ratio and progressive ratio (PR) schedules of reinforcement. The possibility that nicotine-paired cues are as important as nicotine in smoking behavior should refocus our attention on the psychology and neurobiology of conditioned reinforcers in order to stimulate the development of more effective treatment programs for smoking cessation.
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Affiliation(s)
- A R Caggiula
- Department of Psychology, 455 Langley Hall, University of Pittsburgh, Pittsburgh, PA 15260, USA.
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