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Smoking family, secondhand smoke exposure at home, and nicotine addiction among adolescent smokers. Addict Behav 2012; 37:743-6. [PMID: 22406053 DOI: 10.1016/j.addbeh.2012.02.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2012] [Revised: 02/14/2012] [Accepted: 02/21/2012] [Indexed: 11/20/2022]
Abstract
INTRODUCTION Smoking family predicts adolescent smoking, but whether the level of nicotine addiction is affected by exposure to secondhand smoke (SHS) is unclear. We investigated the associations of smoking family and SHS exposure at home with morning smoking and heavier smoking among Chinese adolescent smokers. METHODS In a school-based anonymous survey, 2182 adolescent smokers reported their smoking behaviors, smoking status of family members and peers, and SHS exposure at home and outside home in the past 7 days. Families with one or more smoking members (excluding the subject) were classified as smoking families and otherwise as non-smoking families. Smoking or wanting to smoke first thing in the morning (morning smoking), and consuming more cigarettes (heavier smoking) denoted higher levels of nicotine addiction. Regression analysis yielded adjusted odds ratios (AORs) for morning smoking and β-coefficients for heavier smoking adjusting for potential confounders. RESULTS Living with siblings and other co-residing family members who smoked was significantly associated with morning smoking and heavier smoking. Compared with non-smoking families without SHS exposure at home, the AORs (95% CI) for morning smoking were 0.99 (0.76 to 1.29) for 0 day/week, 1.19 (0.95 to 1.50) for 1-3 days/week, 1.76 (1.41 to 2.21) for 4-7 days/week (p for trend <0.001) and 1.50 (1.23 to 1.83) for any days/week of SHS exposure at home in smoking families. Similarly, 4-6 days/week of SHS exposure at home significantly predicted heavier smoking. CONCLUSION Living with smoking family members and SHS exposure at home are associated with nicotine addiction in Chinese adolescent smokers.
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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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Abstract
Among the human population, 15% of drug users develop a pathological drug addiction. This figure increases substantially with nicotine, whereby more than 30% of those who try smoking develop a nicotine addiction. Drug addiction is characterized by compulsive drug-seeking and drug-taking behaviors (craving), and loss of control over intake despite impairment in health, social, and occupational functions. This behavior can be accurately modeled in the rat using an intravenous self-administration (IVSA) paradigm. Initial attempts at establishing nicotine self-administration had been problematic, yet in recent times increasingly reliable models of nicotine self-administration have been developed. The present article reviews different characteristics of the nicotine IVSA model that has been developed to examine nicotine reinforcing and motivational properties in rats.
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Bruijnzeel AW, Rodrick G, Singh RP, Derendorf H, Bauzo RM. Repeated pre-exposure to tobacco smoke potentiates subsequent locomotor responses to nicotine and tobacco smoke but not amphetamine in adult rats. Pharmacol Biochem Behav 2011; 100:109-18. [PMID: 21871478 DOI: 10.1016/j.pbb.2011.08.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2011] [Revised: 07/21/2011] [Accepted: 08/09/2011] [Indexed: 11/19/2022]
Abstract
These studies investigated if pre-exposure to tobacco smoke affects the locomotor response to tobacco smoke, nicotine, and amphetamine in adult rats. The rats were habituated to an open field for 3-4 days and then exposed to tobacco smoke for 2h/day for 13-14 days. The effect of exposure to tobacco smoke on locomotor activity was investigated after 1, 7, and 14 days of smoke exposure and after one 2-hour exposure session that followed a 3-week off period. The effects of tobacco smoke on the locomotor responses to nicotine (0.04 and 0.4 mg/kg, base) and amphetamine (0.1 and 0.5mg/kg) were investigated on day 14, one day after the last smoke exposure session. The locomotor response to tobacco smoke was increased after 7 and 14 days of smoke exposure and after one exposure session after the 3-week off-period. The acute administration of the high dose of nicotine (0.4 mg/kg) led to a brief period of hypoactivity that was followed by a period of hyperactivity. Pre-exposure to tobacco smoke attenuated the nicotine-induced hypoactivity and potentiated the nicotine-induced hyperactivity. The low dose of nicotine (0.04 mg/kg) did not affect locomotor activity in the control rats but increased the total distance traveled in the tobacco smoke exposed rats. Exposure to tobacco smoke did not affect the locomotor response to amphetamine. These findings indicate that exposure to tobacco smoke leads to tolerance to the depressant effects of nicotine and potentiates the stimulant effects of nicotine and tobacco smoke.
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Affiliation(s)
- Adrie W Bruijnzeel
- Department of Psychiatry, College of Medicine, McKnight Brain Institute, University of Florida, 100 S. Newell Dr., Gainesville, FL 32610, USA
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Marti F, Arib O, Morel C, Dufresne V, Maskos U, Corringer PJ, de Beaurepaire R, Faure P. Smoke extracts and nicotine, but not tobacco extracts, potentiate firing and burst activity of ventral tegmental area dopaminergic neurons in mice. Neuropsychopharmacology 2011; 36:2244-57. [PMID: 21716264 PMCID: PMC3176561 DOI: 10.1038/npp.2011.112] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2010] [Revised: 04/21/2011] [Accepted: 05/08/2011] [Indexed: 11/08/2022]
Abstract
Nicotine prominently mediates the behavioral effects of tobacco consumption, either through smoking or when taking tobacco by snuff or chew. However, many studies question the exclusive role of nicotine in these effects. The use of preparations containing all the components of tobacco, such as tobacco and smoke extracts, may be more suitable than nicotine alone to investigate the behavioral effects of smoking and tobacco intake. In the present study, the electrophysiological effects of tobacco and smoke on ventral tegmental area dopaminergic (DA) neurons were examined in vivo in anesthetized wild-type (WT), β2-nicotinic acetylcholine receptor (nAChR) knockout (β2-/-), α4-/-, and α6-/- mice and compared with those of nicotine alone. In WT mice, smoke and nicotine had similar potentiating effects on DA cell activity, but the action of tobacco on neuronal firing was weak and often inhibitory. In particular, nicotine triggered strong bursting activity, whereas no bursting activity was observed after tobacco extract (ToE) administration. In β2-/- mice, nicotine or extract elicited no modification of the firing patterns of DA cells, indicating that extract acts predominantly through nAChRs. The differences between DA cell activation profiles induced by tobacco and nicotine alone observed in WT persisted in α6-/- mice but not in α4-/- mice. These results would suggest that tobacco has lower addiction-generating properties compared with either nicotine alone or smoke. The weak activation and prominent inhibition obtained with ToEs suggest that tobacco contains compounds that counteract some of the activating effects of nicotine and promote inhibition on DA cell acting through α4β2*-nAChRs. The nature of these compounds remains to be elucidated. It nevertheless confirms that nicotine is the main substance involved in the tobacco addiction-related activation of mesolimbic DA neurons.
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Affiliation(s)
- Fabio Marti
- Neurobiologie des Processus Adaptatifs, CNRS UMR 7102, University P. et M. Curie, Paris, France
| | - Ouafa Arib
- Laboratoire de Psychopharmacologie, Centre Hospitalier Paul Guiraud, Villejuif, France
| | - Carole Morel
- Neurobiologie des Processus Adaptatifs, CNRS UMR 7102, University P. et M. Curie, Paris, France
| | - Virginie Dufresne
- Institut Pasteur, Groupe Récepteurs-Canaux, CNRS URA 2182, Paris, France
| | - Uwe Maskos
- Institut Pasteur, Unité Neurobiologie Intégrative des Systèmes Cholinergiques, CNRS URA 2182, Paris, France
| | | | - Renaud de Beaurepaire
- Laboratoire de Psychopharmacologie, Centre Hospitalier Paul Guiraud, Villejuif, France
| | - Philippe Faure
- Neurobiologie des Processus Adaptatifs, CNRS UMR 7102, University P. et M. Curie, Paris, France
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Tobacco smoke diminishes neurogenesis and promotes gliogenesis in the dentate gyrus of adolescent rats. Brain Res 2011; 1413:32-42. [PMID: 21840504 DOI: 10.1016/j.brainres.2011.07.041] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2011] [Revised: 06/28/2011] [Accepted: 07/19/2011] [Indexed: 11/20/2022]
Abstract
Brain disorders and environmental factors can affect neurogenesis and gliogenesis in the hippocampus. These studies investigated the effects of chronic exposure to tobacco smoke on progenitor cell proliferation and the survival and phenotype of new cells in the dentate gyrus of adolescent rats. The rats were exposed to tobacco smoke for 4h/day for 14 days. To investigate cell proliferation, the exogenous marker 5-bromo-2'-deoxyuridine (BrdU, 200mg/kg, ip) was administered 2h into the 4-h smoke exposure session on day 14. The rats were sacrificed 2-4h after the administration of BrdU. To investigate cell survival, the same dose of BrdU was administered 24h before the start of the 14-day smoke exposure period. These rats were sacrificed 24h after the last smoke exposure session. Tobacco smoke exposure decreased both the number of dividing progenitor cells (-19%) and the number of surviving new cells (-20%), labeled with BrdU in the dentate gyrus. The decrease in cell proliferation was not associated with an increase in apoptotic cell death, as shown by TUNEL analysis. Colocalization studies indicated that exposure to tobacco smoke decreased the number of new immature neurons (BrdU/DCX-positive) and transition neurons (BrdU/DCX/NeuN-positive) and increased the number of new glial cells (BrdU/GFAP-positive). These findings demonstrate that exposure to tobacco smoke diminishes neurogenesis and promotes gliogenesis in the dentate gyrus of adolescent rats. These effects may play a role in the increased risk for depression and cognitive impairment in adolescent smokers.
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Dani JA, Balfour DJK. Historical and current perspective on tobacco use and nicotine addiction. Trends Neurosci 2011; 34:383-92. [PMID: 21696833 DOI: 10.1016/j.tins.2011.05.001] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2010] [Revised: 05/03/2011] [Accepted: 05/03/2011] [Indexed: 01/18/2023]
Abstract
Although the addictive influence of tobacco was recognized very early, the modern concepts of nicotine addiction have relied on knowledge of cholinergic neurotransmission and nicotinic acetylcholine receptors (nAChRs). The discovery of the 'receptive substance' by Langley, that would turn out to be nAChRs, and 'Vagusstoff' (acetylcholine) by Loewi, coincided with an exciting time when the concept of chemical synaptic transmission was being formulated. More recently, the application of more powerful techniques and the study of animal models that replicate key features of nicotine dependence have led to important advancements in our understanding of molecular, cellular and systems mechanisms of nicotine addiction. In this review, we present a historical perspective and overview of the research that has led to our present understanding of nicotine addiction.
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Affiliation(s)
- John A Dani
- Center on Addiction, Learning, Memory, Department of Neuroscience, Menninger Department of Psychiatry and Behavioral Science, Baylor College of Medicine, Houston, TX 77030, USA
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Racicot S, McGrath JJ, O'Loughlin J. An investigation of social and pharmacological exposure to secondhand tobacco smoke as possible predictors of perceived nicotine dependence, smoking susceptibility, and smoking expectancies among never-smoking youth. Nicotine Tob Res 2011; 13:926-33. [PMID: 21622492 DOI: 10.1093/ntr/ntr100] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
INTRODUCTION Recent studies evidenced that adolescent never-smokers exposed to secondhand tobacco smoke (SHS) endorsed nicotine dependence symptoms. Other studies showed that SHS exposure measured with biomarkers among never-smokers independently predicted withdrawal sensations and prospective smoking initiation. The aim of the present study was to replicate and extend these findings by investigating whether social and pharmacological measures of SHS exposure predicted precursors to smoking among never-smoking adolescents. METHODS Participants included 327 never-smokers aged 11-15 years attending sixth or seventh grade in French language schools in Montréal, Canada. They completed self-report questionnaires measuring their smoking status, social smoke exposure (number of smokers in their environment and number of situations where SHS exposure occurs), and precursors to smoking initiation (smoking expectancies, perceived nicotine dependence, and smoking susceptibility). Each participant provided a saliva sample from which cotinine biomarkers were derived to measure pharmacological exposure to SHS. RESULTS When predictors were modeled individually, number of smokers predicted perceived nicotine dependence (p ≤ .05), smoking susceptibility (p ≤ .001), and expected benefits (p ≤ .05), whereas number of situations predicted smoking susceptibility (p ≤ .01). When predictors were modeled simultaneously, number of smokers predicted perceived nicotine dependence (p ≤ .01), smoking susceptibility (p ≤ .01), and expected benefits (p ≤ .05). CONCLUSIONS Social smoke exposure was a predictor for smoking precursors. Pharmacological exposure to SHS did not predict smoking precursors, which may be partly attributable to the low cotinine values observed in our sample. Suggestions for improved pharmacological measurement of SHS and implications for public health are discussed.
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Affiliation(s)
- Simon Racicot
- Pediatric Public Health Psychology Laboratory, Department of Psychology, Concordia University, Montréal, Québec, Canada.
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59
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Brody AL, Mandelkern MA, London ED, Khan A, Kozman D, Costello MR, Vellios EE, Archie MM, Bascom R, Mukhin AG. Effect of secondhand smoke on occupancy of nicotinic acetylcholine receptors in brain. ACTA ACUST UNITED AC 2011; 68:953-60. [PMID: 21536968 DOI: 10.1001/archgenpsychiatry.2011.51] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
CONTEXT Despite progress in tobacco control, secondhand smoke (SHS) exposure remains prevalent worldwide and is implicated in the initiation and maintenance of cigarette smoking. OBJECTIVE To determine whether moderate SHS exposure results in brain α(4)β(2)* nicotinic acetylcholine receptor (nAChR) occupancy. DESIGN, SETTING, AND PARTICIPANTS Positron emission tomography scanning and the radiotracer 2-[18F]fluoro-3-(2(S)azetidinylmethoxy) pyridine (also known as 2-[(18)F]fluoro-A-85380, or 2-FA) were used to determine α(4)β(2)* nAChR occupancy from SHS exposure in 24 young adult participants (11 moderately dependent cigarette smokers and 13 nonsmokers). Participants underwent two bolus-plus-continuous-infusion 2-FA positron emission tomography scanning sessions during which they sat in the passenger's seat of a car for 1 hour and either were exposed to moderate SHS or had no SHS exposure. The study took place at an academic positron emission tomography center. Main Outcome Measure Changes induced by SHS in 2-FA specific binding volume of distribution as a measure of α(4)β(2)* nAChR occupancy. RESULTS An overall multivariate analysis of variance using specific binding volume of distribution values revealed a significant main effect of condition (SHS vs control) (F(1,22) = 42.5, P < .001) but no between-group (smoker vs nonsmoker) effect. Exposure to SHS led to a mean 19% occupancy of brain α(4)β(2)* nAChRs (1-sample t test, 2-tailed, P < .001). Smokers had both a mean 23% increase in craving with SHS exposure and a correlation between thalamic α(4)β(2)* nAChR occupancy and craving alleviation with subsequent cigarette smoking (Spearman ρ = -0.74, P = .01). CONCLUSIONS Nicotine from SHS exposure results in substantial brain α(4)β(2)* nAChR occupancy in smokers and nonsmokers. Study findings suggest that such exposure delivers a priming dose of nicotine to the brain that contributes to continued cigarette use in smokers. This study has implications for both biological research into the link between SHS exposure and cigarette use and public policy regarding the need to limit SHS exposure in cars and other enclosed spaces.
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Affiliation(s)
- Arthur L Brody
- Department of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles, USA.
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Pravetoni M, Keyler DE, Raleigh MD, Harris AC, Lesage MG, Mattson CK, Pettersson S, Pentel PR. Vaccination against nicotine alters the distribution of nicotine delivered via cigarette smoke inhalation to rats. Biochem Pharmacol 2011; 81:1164-70. [PMID: 21333633 PMCID: PMC3072463 DOI: 10.1016/j.bcp.2011.02.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2011] [Revised: 02/08/2011] [Accepted: 02/09/2011] [Indexed: 11/19/2022]
Abstract
Preclinical models of nicotine vaccine pharmacology have relied on i.v. or s.c. administration of nicotine. Models using cigarette smoke inhalation might more accurately simulate nicotine exposure in smokers. Nicotine vaccine effects were examined in rats using two cigarette smoke exposure models: a 10 min nose-only exposure (NSE) producing serum nicotine levels equivalent to the nicotine boost from 1 cigarette in a smoker, and a 2h whole-body exposure (WBE) producing serum nicotine levels similar to those associated with regular mid-day smoking. Vaccination prior to 10min smoke NSE reduced nicotine distribution to brain by 90%, comparable to its effect on nicotine administered i.v. Vaccination prior to 2 h smoke WBE reduced nicotine distribution to brain by 35%. The nicotine concentration in broncheoalveolar lavage (BAL) fluid obtained after 2 h WBE was increased by 230% in vaccinated rats but was also increased in rats passively immunized with a nicotine-specific monoclonal antibody, and so was likely due to transfer of antibody from serum rather than local production at the pulmonary mucosa. Nicotine-specific IgA was not detectable in BAL fluid, but titers in serum were appreciable at 21-25% of the IgG titer and could contribute to vaccine efficacy. Both vaccination and passive immunization are effective in reducing nicotine distribution to brain in rats when nicotine is delivered via inhaled cigarette smoke. These data validate results previously obtained in rodents for nicotine vaccines using i.v. or s.c. nicotine dosing and provide a quantitative method for studying aspects of nicotine exposure which are unique to cigarette smoke inhalation.
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Affiliation(s)
- M Pravetoni
- Minneapolis Medical Research Foundation, Minneapolis, MN, USA
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Harris AC, Mattson C, Lesage MG, Keyler DE, Pentel PR. Comparison of the behavioral effects of cigarette smoke and pure nicotine in rats. Pharmacol Biochem Behav 2010; 96:217-27. [PMID: 20494826 DOI: 10.1016/j.pbb.2010.05.008] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2010] [Revised: 05/04/2010] [Accepted: 05/06/2010] [Indexed: 11/16/2022]
Abstract
Animal models of tobacco dependence typically rely on parenteral administration of pure nicotine. Models using cigarette smoke inhalation might more accurately simulate nicotine exposure in smokers. The primary goal of this study was to validate methods for administering cigarette smoke to rats using exposure conditions that were clinically relevant and also produced brain nicotine levels similar to those produced by behaviorally active doses of pure nicotine. A secondary goal was to begin examining the behavioral effects of smoke. Nose-only exposure (NOE) to smoke for 10-45min or whole-body exposure (WBE) to smoke for 1-4h produced serum nicotine concentrations similar to those in smokers (14-55ng/ml), without excessive carbon monoxide exposure. Daily nicotine (0.1mg/kg, s.c.) induced locomotor sensitization whereas 45-min NOE producing brain nicotine levels within the same range did not. Nicotine 0.125mg/kg s.c. reversed withdrawal from a chronic nicotine infusion as measured by elevations in intracranial self-stimulation thresholds whereas 4-h WBE producing similar brain nicotine levels did not. These data demonstrate the feasibility of delivering cigarette smoke to rats at clinically relevant doses, and provide preliminary evidence that the behavioral effects of nicotine delivered in smoke may differ from those of pure nicotine.
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Affiliation(s)
- Andrew C Harris
- Minneapolis Medical Research Foundation, Minneapolis, MN 55404, United States.
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Yamada H, Bishnoi M, Keijzers KFM, van Tuijl IA, Small E, Shah HP, Bauzo RM, Kobeissy FH, Sabarinath SN, Derendorf H, Bruijnzeel AW. Preadolescent tobacco smoke exposure leads to acute nicotine dependence but does not affect the rewarding effects of nicotine or nicotine withdrawal in adulthood in rats. Pharmacol Biochem Behav 2010; 95:401-9. [PMID: 20211642 DOI: 10.1016/j.pbb.2010.02.018] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2009] [Revised: 02/24/2010] [Accepted: 02/28/2010] [Indexed: 10/19/2022]
Abstract
Epidemiological studies indicate that parental smoking increases the risk for smoking in children. However, the underlying mechanisms by which parental smoking increases the risk for smoking are not known. The aim of these studies was to investigate if preadolescent tobacco smoke exposure, postnatal days 21-35, affects the rewarding effects of nicotine and nicotine withdrawal in adult rats. The rewarding effects of nicotine were investigated with the conditioned place preference procedure. Nicotine withdrawal was investigated with the conditioned place aversion procedure and intracranial self-stimulation (ICSS). Elevations in brain reward thresholds in the ICSS paradigm reflect a dysphoric state. Plasma nicotine and cotinine levels in the preadolescent rats immediately after smoke exposure were 188 ng/ml and 716 ng/ml, respectively. Preadolescent tobacco smoke exposure led to the development of nicotine dependence as indicated by an increased number of mecamylamine-precipitated somatic withdrawal signs in the preadolescent tobacco smoke exposed rats compared to the control rats. Nicotine induced a similar place preference in adult rats that had been exposed to tobacco smoke or air during preadolescence. Furthermore, mecamylamine induced place aversion in nicotine dependent rats but there was no effect of preadolescent tobacco smoke exposure. Finally, preadolescent tobacco smoke exposure did not affect the elevations in brain reward thresholds associated with precipitated or spontaneous nicotine withdrawal. These studies indicate that passive exposure to tobacco smoke during preadolescence leads to the development of nicotine dependence but preadolescent tobacco smoke exposure does not seem to affect the rewarding effects of nicotine or nicotine withdrawal in adulthood.
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Affiliation(s)
- Hidetaka Yamada
- Department of Psychiatry, College of Medicine, McKnight Brain Institute, University of Florida, Gainesville, FL 32610, USA
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