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Pochapski JA, Gómez-A A, Stringfield SJ, Jaggers H, Boettiger CA, Da Cunha C, Robinson DL. Adolescent alcohol exposure persistently alters orbitofrontal cortical encoding of Pavlovian conditional stimulus components in female rats. Sci Rep 2024; 14:13775. [PMID: 38877100 PMCID: PMC11178901 DOI: 10.1038/s41598-024-64036-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Accepted: 06/04/2024] [Indexed: 06/16/2024] Open
Abstract
Exposure to alcohol during adolescence impacts cortical and limbic brain regions undergoing maturation. In rodent models, long-term effects on behavior and neurophysiology have been described after adolescent intermittent ethanol (AIE), especially in males. We hypothesized that AIE in female rats increases conditional approach to a reward-predictive cue and corresponding neuronal activity in the orbitofrontal cortex (OFC) and nucleus accumbens (NAc). We evaluated behavior and neuronal firing after AIE (5 g/kg intragastric) or water (CON) in adult female rats. Both AIE and CON groups expressed a ST phenotype, and AIE marginally increased sign-tracking (ST) and decreased goal-tracking (GT) metrics. NAc neurons exhibited phasic firing patterns to the conditional stimulus (CS), with no differences between groups. In contrast, neuronal firing in the OFC of AIE animals was greater at CS onset and offset than in CON animals. During reward omission, OFC responses to CS offset normalized to CON levels, but enhanced OFC firing to CS onset persisted in AIE. We suggest that the enhanced OFC neural activity observed in AIE rats to the CS could contribute to behavioral inflexibility. Ultimately, AIE persistently impacts the neurocircuitry of reward-motivated behavior in female rats.
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Affiliation(s)
- Jose A Pochapski
- Laboratorio de Fisiologia e Farmacologia do Sistema Nervoso Central, Department of Pharmacology, Universidade Federal do Parana, Curitiba, PR, Brazil
| | - Alexander Gómez-A
- Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | | | - Hannah Jaggers
- Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Charlotte A Boettiger
- Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Department of Psychology and Neuroscience, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Claudio Da Cunha
- Laboratorio de Fisiologia e Farmacologia do Sistema Nervoso Central, Department of Pharmacology, Universidade Federal do Parana, Curitiba, PR, Brazil
- Department of Biochemistry, Universidade Federal do Parana, Curitiba, PR, Brazil
| | - Donita L Robinson
- Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
- Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
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King CP, Chitre AS, Leal-Gutiérrez JD, Tripi JA, Hughson AR, Horvath AP, Lamparelli AC, George A, Martin C, Pierre CLS, Sanches T, Bimschleger HV, Gao J, Cheng R, Nguyen KM, Holl KL, Polesskaya O, Ishiwari K, Chen H, Woods LCS, Palmer AA, Robinson TE, Flagel SB, Meyer PJ. Genomic Loci Influencing Cue-Reactivity in Heterogeneous Stock Rats. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.13.584852. [PMID: 38559127 PMCID: PMC10980002 DOI: 10.1101/2024.03.13.584852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Addiction vulnerability is associated with the tendency to attribute incentive salience to reward predictive cues; both addiction and the attribution of incentive salience are influenced by environmental and genetic factors. To characterize the genetic contributions to incentive salience attribution, we performed a genome-wide association study (GWAS) in a cohort of 1,645 genetically diverse heterogeneous stock (HS) rats. We tested HS rats in a Pavlovian conditioned approach task, in which we characterized the individual responses to food-associated stimuli ("cues"). Rats exhibited either cue-directed "sign-tracking" behavior or food-cup directed "goal-tracking" behavior. We then used the conditioned reinforcement procedure to determine whether rats would perform a novel operant response for unrewarded presentations of the cue. We found that these measures were moderately heritable (SNP heritability, h2 = .189-.215). GWAS identified 14 quantitative trait loci (QTLs) for 11 of the 12 traits we examined. Interval sizes of these QTLs varied widely. 7 traits shared a QTL on chromosome 1 that contained a few genes (e.g. Tenm4, Mir708) that have been associated with substance use disorders and other mental health traits in humans. Other candidate genes (e.g. Wnt11, Pak1) in this region had coding variants and expression-QTLs in mesocorticolimbic regions of the brain. We also conducted a Phenome-Wide Association Study (PheWAS) on other behavioral measures in HS rats and found that regions containing QTLs on chromosome 1 were also associated with nicotine self-administration in a separate cohort of HS rats. These results provide a starting point for the molecular genetic dissection of incentive salience and provide further support for a relationship between attribution of incentive salience and drug abuse-related traits.
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Affiliation(s)
- Christopher P. King
- Department of Psychology, University at Buffalo, Buffalo, USA
- Clinical and Research Institute on Addictions, Buffalo, USA
| | - Apurva S. Chitre
- Department of Psychiatry, University of California San Diego, La Jolla, USA
| | | | - Jordan A. Tripi
- Department of Psychology, University at Buffalo, Buffalo, USA
| | - Alesa R. Hughson
- Department of Psychology, University of Michigan, Ann Arbor, USA
| | - Aidan P. Horvath
- Department of Psychology, University of Michigan, Ann Arbor, USA
| | | | - Anthony George
- Clinical and Research Institute on Addictions, Buffalo, USA
| | - Connor Martin
- Clinical and Research Institute on Addictions, Buffalo, USA
| | | | - Thiago Sanches
- Department of Psychiatry, University of California San Diego, La Jolla, USA
| | | | - Jianjun Gao
- Department of Psychiatry, University of California San Diego, La Jolla, USA
| | - Riyan Cheng
- Department of Psychiatry, University of California San Diego, La Jolla, USA
| | - Khai-Minh Nguyen
- Department of Psychiatry, University of California San Diego, La Jolla, USA
| | - Katie L. Holl
- Department of Physiology, Medical College of Wisconsin, Milwaukee, USA
| | - Oksana Polesskaya
- Department of Psychiatry, University of California San Diego, La Jolla, USA
| | - Keita Ishiwari
- Clinical and Research Institute on Addictions, Buffalo, USA
- Department of Pharmacology and Toxicology, University at Buffalo, Buffalo USA
| | - Hao Chen
- Department of Pharmacology, Addiction Science and Toxicology, University of Tennessee Health Science Center, Memphis, USA
| | - Leah C. Solberg Woods
- Department of Internal Medicine, Molecular Medicine, Center on Diabetes, Obesity and Metabolism, Wake Forest School of Medicine, Winston-Salem, USA
| | - Abraham A. Palmer
- Department of Psychiatry, University of California San Diego, La Jolla, USA
- Institute for Genomic Medicine, University of California San Diego, La Jolla, USA
| | | | - Shelly B. Flagel
- Department of Psychiatry, University of Michigan, Ann Arbor, USA
- Michigan Neuroscience Institute, University of Michigan, Ann Arbor, USA
| | - Paul J. Meyer
- Department of Psychology, University at Buffalo, Buffalo, USA
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Maddux JM, Gonzales L, Kregar NP. β2* nicotinic acetylcholine receptor subtypes mediate nicotine-induced enhancement of Pavlovian conditioned responding to an alcohol cue. Front Behav Neurosci 2022; 16:1004368. [PMCID: PMC9596985 DOI: 10.3389/fnbeh.2022.1004368] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Accepted: 09/21/2022] [Indexed: 11/13/2022] Open
Abstract
Nicotine enhances Pavlovian conditioned responses to reward-associated cues. We investigated through which nicotinic acetylcholine receptor (nAChR) subtypes nicotine acts to produce this behavioral effect to an alcohol-associated cue. Male Long-Evans rats with freely available food and water were first accustomed to drinking 15% ethanol in their home cages using an intermittent access, two-bottle choice procedure. Then the rats were given 15 Pavlovian conditioning sessions in which a 15-s audiovisual conditioned stimulus (CS) predicted the delivery of 0.2 ml of ethanol, the unconditioned stimulus (US). Each session contained 12 CS-US trials. A control group received explicitly unpaired presentations of the CS and US. We measured Pavlovian conditioned approach to the site of US delivery during presentations of the CS, accounting for pre-CS baseline activity. Before each conditioning session, rats were injected subcutaneously with nicotine (0.4 mg/kg) or saline (1 ml/kg). During nAChR antagonist test sessions, rats were first injected systemically with the β2*-selective nAChR antagonist dihydro-beta-erythroidine (DHβE; 3 mg/kg) or the α7-selective nAChR antagonist methyllycaconitine (MLA; 6 mg/kg), followed by their assigned nicotine or saline injection before assessing their conditioned response to the alcohol-associated cue. Consistent with previous reports, nicotine enhanced the Pavlovian conditioned response to the alcohol-paired cue. DHβE attenuated this enhancement, whereas MLA did not. These results suggest that nicotine acts via β2*, but not α7, nAChRs to amplify Pavlovian conditioned responding to an alcohol cue. These findings contribute to a growing literature that identifies nAChRs as potential targets for pharmacological treatment of co-morbid alcohol and tobacco use disorders.
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Affiliation(s)
- Jean-Marie Maddux
- Department of Psychology, Lake Forest College, Lake Forest, IL, United States
- Neuroscience Program, Lake Forest College, Lake Forest, IL, United States
- *Correspondence: Jean-Marie Maddux
| | - Leslie Gonzales
- Department of Psychology, Lake Forest College, Lake Forest, IL, United States
- Neuroscience Program, Lake Forest College, Lake Forest, IL, United States
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King CP, Meyer PJ. The incentive amplifying effects of nicotine: Roles in alcohol seeking and consumption. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2022; 93:171-218. [PMID: 35341566 DOI: 10.1016/bs.apha.2021.10.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Nicotine has a unique profile among drugs of abuse. To the noninitiated user, nicotine has powerful aversive effects and its relatively weak euphorigenic effects undergo rapid tolerance. Despite this, nicotine is commonly abused despite negative heath consequences, and nicotine users have enormous difficulty quitting. Further, nicotine is one of the most commonly co-abused substances, in that it is often taken in combination with other drugs. One explanation of this polydrug use is that nicotine has multiple appetitive and consummatory conditioning effects. For example, nicotine is a reinforcement enhancer in that it can potently increase the incentive value of other stimuli, including those surrounding drugs of abuse such as alcohol. In addition, nicotine also has a unique profile of neurobiological effects that alter regulation of alcohol intake and interoception. This review discusses the psychological and biological mechanisms surrounding nicotine's appetitive conditioning and consummatory effects, particularly its interactions with alcohol.
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Affiliation(s)
- Christopher P King
- Department of Psychology, State University of New York at Buffalo, Buffalo, NY, United States; Clinical and Research Institute on Addictions, State University of New York at Buffalo, Buffalo, NY, United States
| | - Paul J Meyer
- Department of Psychology, State University of New York at Buffalo, Buffalo, NY, United States.
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Stowe TA, Pitts EG, Leach AC, Iacino MC, Niere F, Graul B, Raab-Graham KF, Yorgason JT, Ferris MJ. Diurnal rhythms in cholinergic modulation of rapid dopamine signals and associative learning in the striatum. Cell Rep 2022; 39:110633. [PMID: 35385720 PMCID: PMC9148619 DOI: 10.1016/j.celrep.2022.110633] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Revised: 12/20/2021] [Accepted: 03/16/2022] [Indexed: 11/26/2022] Open
Abstract
Dysregulation of biological rhythms plays a role in a wide range of psychiatric disorders. We report mechanistic insights into the rhythms of rapid dopamine signals and cholinergic interneurons (CINs) working in concert in the rodent striatum. These rhythms mediate diurnal variation in conditioned responses to reward-associated cues. We report that the dopamine signal-to-noise ratio varies according to the time of day and that phasic signals are magnified during the middle of the dark cycle in rats. We show that CINs provide the mechanism for diurnal variation in rapid dopamine signals by serving as a gain of function to the dopamine signal-to-noise ratio that adjusts across time of day. We also show that conditioned responses to reward-associated cues exhibit diurnal rhythms, with cue-directed behaviors observed exclusively midway through the dark cycle. We conclude that the rapid dopamine signaling rhythm is mediated by a diurnal rhythm in CIN activity, which influences learning and motivated behaviors across the time of day.
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Affiliation(s)
- Taylor A Stowe
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, 1 Medical Center Blvd., Winston-Salem, NC 27157, USA
| | - Elizabeth G Pitts
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, 1 Medical Center Blvd., Winston-Salem, NC 27157, USA
| | - Amy C Leach
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, 1 Medical Center Blvd., Winston-Salem, NC 27157, USA
| | - Melody C Iacino
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, 1 Medical Center Blvd., Winston-Salem, NC 27157, USA
| | - Farr Niere
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, 1 Medical Center Blvd., Winston-Salem, NC 27157, USA
| | - Benjamin Graul
- Department of Cellular Biology and Physiology, Neuroscience Center, Brigham Young University, Provo, UT 84602, USA
| | - Kimberly F Raab-Graham
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, 1 Medical Center Blvd., Winston-Salem, NC 27157, USA
| | - Jordan T Yorgason
- Department of Cellular Biology and Physiology, Neuroscience Center, Brigham Young University, Provo, UT 84602, USA
| | - Mark J Ferris
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, 1 Medical Center Blvd., Winston-Salem, NC 27157, USA.
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McNealy KR, Houser SD, Barrett ST, Bevins RA. Investigating sex differences and the effect of drug exposure order in the sensory reward-enhancing effects of nicotine and d-amphetamine alone and in combination. Neuropharmacology 2022; 202:108845. [PMID: 34678376 PMCID: PMC8627442 DOI: 10.1016/j.neuropharm.2021.108845] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 09/30/2021] [Accepted: 10/15/2021] [Indexed: 01/03/2023]
Abstract
Nicotine enhances the rewarding effects of other environmental stimuli; this reward-enhancement encourages and maintains nicotine consumption. Nicotine use precedes other psychostimulant use, but receiving a stimulant prescription also predicts future smoking. Previously, no study has investigated effects of drug exposure order in reward-enhancement, nor with nicotine and d-amphetamine. Thus, we aimed to investigate how drug exposure order impacted the reward-enhancing effects of nicotine and d-amphetamine, alone and in combination. We used 20 male and 20 female Sprague-Dawley rats. Enhancement was investigated within-subjects by examining responding maintained by a visual stimulus reinforcer following a pre-session injection of either d-amphetamine (Sal, 0.1, 0.3, or 0.6 mg/kg) or nicotine (Sal, 0.03, 0.06, 0.1, 0.3 mg/kg). Twenty rats (10 M, 10 F) completed enhancement testing with nicotine before d-amphetamine. The other 20 rats (10 M, 10 F) completed testing with d-amphetamine before nicotine. Following these phases, rats were then given two pre-session injections: one of d-amphetamine (Sal, 0.1, 0.3, or 0.6 mg/kg) and another of nicotine (Sal, 0.03, 0.06, 0.1, or 0.3 mg/kg). Experiencing amphetamine before nicotine increased reward-enhancing effects of nicotine. Females exhibited greater effects of d-amphetamine on reward-enhancement, with no effect of exposure order. During the interaction phase, receiving nicotine before amphetamine enhanced the interaction between nicotine and d-amphetamine for females whereas amphetamine before nicotine heightened this interaction for males. From this, prior and current amphetamine use, in addition to sex, should be considered when treating nicotine dependency and when examining factors driving poly-substance use involving nicotine and d-amphetamine. Keywords: Adderall, ADHD, Dexedrine, operant, smoking, polysubstance use.
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Affiliation(s)
- Kathleen R McNealy
- Department of Psychology University of Nebraska-Lincoln, 238 Burnett Hall, Lincoln, NE, 68588-0308, USA
| | - Sydney D Houser
- Department of Psychology University of Nebraska-Lincoln, 238 Burnett Hall, Lincoln, NE, 68588-0308, USA
| | - Scott T Barrett
- Department of Psychology University of Nebraska-Lincoln, 238 Burnett Hall, Lincoln, NE, 68588-0308, USA
| | - Rick A Bevins
- Department of Psychology University of Nebraska-Lincoln, 238 Burnett Hall, Lincoln, NE, 68588-0308, USA.
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Angelyn H, Loney GC, Meyer PJ. Nicotine Enhances Goal-Tracking in Ethanol and Food Pavlovian Conditioned Approach Paradigms. Front Neurosci 2021; 15:561766. [PMID: 34483813 PMCID: PMC8416423 DOI: 10.3389/fnins.2021.561766] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 07/20/2021] [Indexed: 11/13/2022] Open
Abstract
Rationale Nicotine promotes alcohol intake through pharmacological and behavioral interactions. As an example of the latter, nicotine can facilitate approach toward food- and alcohol-associated stimuli ("sign-tracking") in lever-Pavlovian conditioned approach (PavCA) paradigms. However, we recently reported that nicotine can also enhance approach toward locations of reward delivery ("goal-tracking") triggered by ethanol-predictive stimuli when the location of ethanol delivery is non-static (i.e., a retractable sipper bottle). Objective To determine whether the non-static nature of the reward location could have biased the development of goal-tracking in our previous study (Loney et al., 2019); we assessed the effect of nicotine in a lever-PavCA paradigm wherein the location of ethanol delivery was static (i.e., a stationary liquid receptacle). Then, to determine whether nicotine's enhancement of goal-tracking is unique to ethanol-predictive stimuli, we assessed the effect of systemic nicotine on approach triggered by food-predictive stimuli in a lever-PavCA paradigm. Methods Long-Evans rats were used in two PavCA experiments wherein a lever predicted the receipt of ethanol (15% vol/vol; experiment 1) or food (experiment 2) into a stationary receptacle. Prior to testing, rats were administered nicotine (0.4 mg/kg subcutaneously) or saline systemically. Results In both experiments, nicotine increased measures of goal-tracking, but not sign-tracking. Conclusion Nicotine can facilitate approach to reward locations without facilitating approach to reward-predictive stimuli. As such, conceptualization of the mechanisms by which nicotine affects behavior must be expanded to explain an enhancement of goal-tracking by nicotine.
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Affiliation(s)
- Hailley Angelyn
- Behavioral Neuroscience Program, Department of Psychology, State University of New York at Buffalo, Buffalo, NY, United States
| | - Gregory C Loney
- Behavioral Neuroscience Program, Department of Psychology, State University of New York at Buffalo, Buffalo, NY, United States
| | - Paul J Meyer
- Behavioral Neuroscience Program, Department of Psychology, State University of New York at Buffalo, Buffalo, NY, United States
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Robison CL, Kazan T, Miller RLA, Cova N, Charntikov S. Inactivation of posterior but not anterior dorsomedial caudate-putamen impedes learning with self-administered nicotine stimulus in male rats. Behav Brain Res 2021; 413:113438. [PMID: 34224762 DOI: 10.1016/j.bbr.2021.113438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 06/24/2021] [Accepted: 06/27/2021] [Indexed: 11/17/2022]
Abstract
The rodent caudate-putamen is a large heterogeneous neural structure with distinct anatomical connections that differ in their control of learning processes. Previous research suggests that the anterior and posterior dorsomedial caudate-putamen (a- and p-dmCPu) differentially regulate associative learning with a non-contingent nicotine stimulus. The current study used bilateral NMDA-induced excitotoxic lesions to the a-dmCPu and p-dmCPu to determine the functional involvement of a-dmCPu and p-dmCPu in appetitive learning with contingent nicotine stimulus. Rats with a-dmCPu, p-dmCPu, or sham lesions were trained to lever-press for intravenous nicotine (0.03 mg/kg/inf) followed by access to sucrose 30 s later. After 1, 3, 9, and 20 nicotine-sucrose training sessions, appetitive learning in the form of a goal-tracking response was assessed using a non-contingent nicotine-alone test. All rats acquired nicotine self-administration and learned to retrieve sucrose from a receptacle at equal rates. However, rats with lesions to p-dmCPu demonstrated blunted learning of the nicotine-sucrose association. Our primary findings show that rats with lesions to p-dmCPu had a blunted goal-tracking response to a non-contingent nicotine administration after 20 consecutive days of nicotine-sucrose pairing. Our findings extend previous reports to a contingent model of nicotine self-administration and show that p-dmCPu is involved in associative learning with nicotine stimulus using a paradigm where rats voluntarily self-administer nicotine infusions that are paired with access to sucrose-a paradigm that closely resembles learning processes observed in humans.
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Affiliation(s)
| | - Theodore Kazan
- Department of Psychology, University of New Hampshire, United States
| | - Rikki L A Miller
- Department of Psychology, University of Southern Maine, United States
| | - Nicole Cova
- Department of Psychology, University of New Hampshire, United States
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Effects of ad libitum feeding and prefeeding on operant responding in sign- and goal-tracking rats. LEARNING AND MOTIVATION 2020. [DOI: 10.1016/j.lmot.2020.101686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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10
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Varenicline rescues nicotine-induced decrease in motivation for sucrose reinforcement. Behav Brain Res 2020; 397:112887. [PMID: 32931838 DOI: 10.1016/j.bbr.2020.112887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 08/25/2020] [Accepted: 08/26/2020] [Indexed: 11/21/2022]
Abstract
Varenicline is one of the top medications used for smoking cessation and is often prescribed before termination of nicotine use. The effect of this combined nicotine and varenicline use on the reward system and motivation for primary reinforcement is underexplored. The goal of this study was to assess the effects of nicotine and varenicline on motivation for a food reinforcer. In Experiment 1, we first assessed the responding for sucrose after pretreatment with nicotine (0, 0.1, or 0.4 mg/kg) and varenicline (0.0, 0.1, 1.0 mg/kg) using a behavioral economics approach. The responding for sucrose was then assessed using a progressive ratio schedule of reinforcement after pretreatment with all possible combinations of nicotine and varenicline doses. In Experiment 2, rats were assessed for the consumption of sucrose in home cages after pretreatment with nicotine and varenicline. We found that (a) nicotine decreased economic demand for sucrose, (b) varenicline rescued nicotine-induced reduction in economic demand for sucrose, and (c) history of varenicline treatment predicted responding for sucrose on a progressive ratio schedule of reinforcement where rats with a history of varenicline treatment responded significantly lower for sucrose across nicotine doses than rats that had not been exposed to varenicline. The results of Experiment 2 largely confirmed that nicotine decreases motivation for sucrose using a passive consumption protocol and that varenicline rescues this effect. Overall, these findings suggest that varenicline interacts with the effects of nicotine by restoring nicotine-induced reduction in motivation for appetitive rewards.
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Palmatier MI, Smith AL, Odineal EM, Williams EA, Sheppard AB, Bradley CA. Nicotine Self-Administration With Tobacco Flavor Additives in Male Rats. Nicotine Tob Res 2020; 22:224-231. [PMID: 30980717 DOI: 10.1093/ntr/ntz053] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Accepted: 04/11/2019] [Indexed: 01/07/2023]
Abstract
INTRODUCTION Nicotine can robustly increase responding for conditioned reinforcers (CRs), stimuli that acquire reinforcing properties based on association with primary reinforcers. Menthol and licorice are tobacco flavoring agents also found in sweet foods (eg, candy and ice cream), making them putative CRs before they are consumed in tobacco. We sought to determine if intravenous self-administration (IVSA) of nicotine was enhanced by the inclusion of oral tobacco flavor CRs. METHODS Menthol (160 or 320 µM) or licorice root extract (0.1% or 1%) were established as CRs (paired with 20% sucrose) or "neutral" stimuli (paired with water) in separate groups. During subsequent IVSA tests, nicotine was delivered in conjunction with oral presentations of the CR. RESULTS In experiment 1, a menthol CR significantly shifted the peak nicotine dose from 15 µg/kg/infusion (Neutral group) to 3.25 µg/kg/infusion (CR group). In experiment 2, a menthol CR significantly increased operant licks for nicotine (3 µg/kg/infusion) relative to control groups. In experiment 3, both licorice and menthol CRs significantly increased operant licks for nicotine (7.5 µg/kg/infusion) relative to an "inactive" sipper. The licorice CR increased nicotine IVSA in proportion to the strength of the flavor, but both menthol concentrations increased nicotine IVSA to a similar extent. CONCLUSION Tobacco flavor additives with conditioned reinforcing properties promote acquisition of nicotine self-administration at low unit doses and may have robust impact on tobacco consumption when nicotine yield is low. IMPLICATIONS Tobacco flavor additives are found in rewarding foods (eg, ice cream) and gain palatability based on associations with primary rewards (eg, sugar) making them "conditioned reinforcers." Nicotine increases the motivation for flavor conditioned reinforcers and the present studies show that tobacco flavor additives can interact with nicotine to promote more nicotine self-administration. The interaction between flavors additives and nicotine may promote nicotine exposure and subsequently dependence.
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Affiliation(s)
| | - Amanda L Smith
- Department of Psychology, East Tennessee State University, Johnson City, TN
| | - Ethan M Odineal
- Department of Psychology, East Tennessee State University, Johnson City, TN
| | - Emily A Williams
- Department of Psychology, East Tennessee State University, Johnson City, TN
| | - Ashley B Sheppard
- Department of Psychology, East Tennessee State University, Johnson City, TN
| | - Curtis A Bradley
- Department of Psychology, East Tennessee State University, Johnson City, TN
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12
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Nicotine Pretreatment Increases Sensitivity to Reward Devaluation in Extinction. PSYCHOLOGICAL RECORD 2020. [DOI: 10.1007/s40732-020-00422-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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13
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Stringfield SJ, Madayag AC, Boettiger CA, Robinson DL. Sex differences in nicotine-enhanced Pavlovian conditioned approach in rats. Biol Sex Differ 2019; 10:37. [PMID: 31315660 PMCID: PMC6637589 DOI: 10.1186/s13293-019-0244-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Accepted: 05/28/2019] [Indexed: 01/01/2023] Open
Abstract
Background Nicotine exposure enhances Pavlovian conditioned approach (PCA), or the learned approach to reward-predictive cues. While females show elevated approach to conditioned stimuli compared to males, potentially indicating heightened addiction vulnerability, it is unknown how sex may interact with nicotine to influence approach behavior. Additionally, brain-derived neurotrophic factor (BDNF) levels can be altered significantly after repeated nicotine exposure, suggesting a potential mechanism contributing to nicotine-induced behavioral phenotypes. The present study investigated the role of sex on nicotine-induced changes to stimulus-response behavior and associated BDNF protein levels. Methods Male and female rats were exposed to nicotine (0.4 mg/kg, subcutaneously) or saline 15 min prior to each PCA session. PCA training consisted of 29 sessions of 15 trials, in which a 30-s cue presentation ended concurrently with a sucrose reward (20% w/v in water, 100 μL), and a 120-s variable intertrial interval occurred between trials. Approach behavior to the cue and reward receptacle was recorded. Preference toward the reward receptacle indicated a goal-tracking phenotype, and preference toward the cue indicated a sign-tracking phenotype, demonstrating that the cue had gained incentive salience. Twenty-four hours after the last PCA session, brain tissue was collected and BDNF levels were measured in the basolateral amygdala, orbitofrontal cortex, and nucleus accumbens using Western blot analysis. Results Nicotine exposure enhanced both sign- and goal-tracking conditioned approach, and females showed elevated sign-tracking compared to males. There were no sex-by-drug interactions on conditioned approach. Day-to-day variability in conditioned approach was similar between sexes. In contrast to prior studies, neither repeated exposure to nicotine nor sex significantly affected BDNF expression. Conclusions Drug-naïve females exhibited heightened sign-tracking compared to males, and nicotine enhanced conditioned approach similarly in males and females. Further, non-significant changes to BDNF expression in brain regions highly associated with PCA indicate that BDNF is unlikely to drive nicotine-enhanced conditioned behavior.
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Affiliation(s)
- Sierra J Stringfield
- Bowles Center for Alcohol Studies, University of North Carolina, CB #7178, Chapel Hill, NC, 27599-7178, USA.,Neuroscience Curriculum, University of North Carolina, Chapel Hill, NC, USA
| | - Aric C Madayag
- Bowles Center for Alcohol Studies, University of North Carolina, CB #7178, Chapel Hill, NC, 27599-7178, USA
| | - Charlotte A Boettiger
- Bowles Center for Alcohol Studies, University of North Carolina, CB #7178, Chapel Hill, NC, 27599-7178, USA.,Neuroscience Curriculum, University of North Carolina, Chapel Hill, NC, USA.,Department of Psychology and Neuroscience, University of North Carolina, Chapel Hill, NC, USA
| | - Donita L Robinson
- Bowles Center for Alcohol Studies, University of North Carolina, CB #7178, Chapel Hill, NC, 27599-7178, USA. .,Neuroscience Curriculum, University of North Carolina, Chapel Hill, NC, USA. .,Department of Psychiatry, University of North Carolina, Chapel Hill, NC, USA.
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14
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Garcia‐Rivas V, Deroche‐Gamonet V. Not all smokers appear to seek nicotine for the same reasons: implications for preclinical research in nicotine dependence. Addict Biol 2019; 24:317-334. [PMID: 29480575 DOI: 10.1111/adb.12607] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Revised: 12/11/2017] [Accepted: 01/15/2018] [Indexed: 01/08/2023]
Abstract
Tobacco use leads to 6 million deaths every year due to severe long-lasting diseases. The main component of tobacco, nicotine, is recognized as one of the most addictive drugs, making smoking cessation difficult, even when 70 percent of smokers wish to do so. Clinical and preclinical studies have demonstrated consistently that nicotine seeking is a complex behavior involving various psychopharmacological mechanisms. Evidence supports that the population of smokers is heterogeneous, particularly as regards the breadth of motives that determine the urge to smoke. Here, we review converging psychological, genetic and neurobiological data from clinical and preclinical studies supporting that the mechanisms controlling nicotine seeking may vary from individual to individual. It appears timely that basic neuroscience integrates this heterogeneity to refine our understanding of the neurobiology of nicotine seeking, as tremendous progress has been made in modeling the various psychopharmacological mechanisms driving nicotine seeking in rodents. For a better understanding of the mechanisms that drive nicotine seeking, we emphasize the need for individual-based research strategies in which nicotine seeking, and eventually treatment efficacy, are determined while taking into account individual variations in the mechanisms of nicotine seeking.
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Affiliation(s)
- Vernon Garcia‐Rivas
- Université de Bordeaux France
- INSERM U1215, Psychobiology of Drug AddictionNeuroCentre Magendie France
| | - Véronique Deroche‐Gamonet
- Université de Bordeaux France
- INSERM U1215, Psychobiology of Drug AddictionNeuroCentre Magendie France
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15
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Loney GC, Angelyn H, Cleary LM, Meyer PJ. Nicotine Produces a High-Approach, Low-Avoidance Phenotype in Response to Alcohol-Associated Cues in Male Rats. Alcohol Clin Exp Res 2019; 43:1284-1295. [PMID: 30958564 DOI: 10.1111/acer.14043] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Accepted: 04/01/2019] [Indexed: 11/28/2022]
Abstract
BACKGROUND Nicotine and alcohol use are highly comorbid. Modulation of drug-paired extrinsic and intrinsic cues likely plays a role in this interaction, as cues can acquire motivational properties and augment drug seeking. The motivational properties of cues can be measured through Pavlovian conditioning paradigms, in which cues either elicit approach following pairing with the reinforcing properties of alcohol or elicit avoidance following pairing with the aversive consequences of alcohol. The present experiments tested whether nicotine would enhance the incentive properties of an appetitive ethanol (EtOH) cue and diminish the avoidance of an aversive EtOH cue in Pavlovian paradigms. METHODS In experiment 1, male Long-Evans rats with or without prior chronic intermittent access to EtOH were administered nicotine or saline injections prior to Pavlovian conditioned approach (PavCA) sessions, during which conditioned approach to the cue ("sign-tracking") or the EtOH delivery location ("goal-tracking") was measured. In experiment 2, male Long-Evans rats were administered nicotine or saline injections prior to pairing a flavor cue with increasing doses of EtOH (i.p.) in an adaptation of the conditioned taste avoidance (CTA) paradigm. RESULTS Results from PavCA indicate that, regardless of EtOH exposure, nicotine enhanced responding elicited by EtOH-paired cues with no effect on a similar cue not explicitly paired with EtOH. Furthermore, nicotine reduced sensitivity to EtOH-induced CTA, as indicated by a rightward shift in the dose-response curve of passively administered EtOH. The ED50 , or the dose of EtOH that produced a 50% reduction in intake relative to baseline, was significantly higher in nicotine-treated rats compared to saline-treated rats. CONCLUSIONS We conclude that nicotine increases the approach and diminishes the avoidance elicited by Pavlovian cues paired, respectively, with the reinforcing and aversive properties of EtOH consumption in male rats. As such, nicotine may enhance alcoholism liability by engendering an attentional bias toward cues that predict the reinforcing outcomes of drinking.
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Affiliation(s)
- Gregory C Loney
- Department of Psychology, Center for Ingestive Behavior Research, University at Buffalo, Buffalo, New York
| | - Hailley Angelyn
- Department of Psychology, Center for Ingestive Behavior Research, University at Buffalo, Buffalo, New York
| | - Liam M Cleary
- Department of Psychology, Center for Ingestive Behavior Research, University at Buffalo, Buffalo, New York
| | - Paul J Meyer
- Department of Psychology, Center for Ingestive Behavior Research, University at Buffalo, Buffalo, New York
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16
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Marshall AT, Ostlund SB. Repeated cocaine exposure dysregulates cognitive control over cue-evoked reward-seeking behavior during Pavlovian-to-instrumental transfer. ACTA ACUST UNITED AC 2018; 25:399-409. [PMID: 30115761 PMCID: PMC6097769 DOI: 10.1101/lm.047621.118] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 05/16/2018] [Indexed: 11/25/2022]
Abstract
Drug-paired cues acquire powerful motivational properties, but only lead to active drug-seeking behavior if they are potent enough to overwhelm the cognitive control processes that serve to suppress such urges. Studies using the Pavlovian-to-instrumental transfer (PIT) task have shown that rats pretreated with cocaine or amphetamine exhibit heightened levels of cue-motivated food-seeking behavior, suggesting that exposure to these drugs sensitizes the incentive motivational system. However, the PIT testing protocol can also create conflict between two competing behavioral responses to the reward-paired cue: active reward seeking (e.g., lever pressing) and passive conditioned food-cup approach behavior. We therefore investigated whether repeated cocaine exposure alters the way in which rats use cue-based reward expectations to resolve such conflict. In-depth analysis of previously published and new research confirmed that when drug-naïve rats are given a cue that signals the timing of a delayed noncontingent reward, they adaptively transition from reward seeking to conditioned approach behavior, facilitating efficient collection of the predicted reward. In contrast, cocaine-exposed rats exhibit pronounced behavioral dysregulation, increasing, rather than suppressing, their reward-seeking behavior over time, disrupting their ability to passively collect reward. Such findings speak to the important and sometimes overlooked role that cognitive control plays in determining the motivational impact of cues associated with drug and nondrug rewards.
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Affiliation(s)
- Andrew T Marshall
- Department of Anesthesiology and Perioperative Care, Irvine Center for Addiction Neuroscience, University of California, Irvine, Irvine, California 92697, USA
| | - Sean B Ostlund
- Department of Anesthesiology and Perioperative Care, Irvine Center for Addiction Neuroscience, University of California, Irvine, Irvine, California 92697, USA
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17
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Vandaele Y, Noe E, Cador M, Dellu-Hagedorn F, Caille S. Attentional capacities prior to drug exposure predict motivation to self-administer nicotine. Psychopharmacology (Berl) 2018; 235:2041-2050. [PMID: 29704216 DOI: 10.1007/s00213-018-4901-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 04/09/2018] [Indexed: 12/24/2022]
Abstract
RATIONALE Nicotine can enhance attention and attribution of incentive salience to nicotine-associated stimuli. However, it is not clear whether inter-individual differences in attentional capacities prior to any exposure could play a role in vulnerability to nicotine self-administration. We further explored this vulnerability through pre-existing inter-individual differences in attention to a reward-predictive cue in drug-free animals. METHODS A cued version of the Fixed Consecutive Number schedule (FCN16cue) of reinforcement task was used to assess attention. This task consists in completing a long chain of sequential lever presses to obtain a reward, and examines the rats' ability to pay attention to a cue light that signals its availability. Rats were then trained to self-administer nicotine intravenously (30 μg/kg/0.1 mL). Drug-taking and seeking behaviors were investigated. RESULTS Our results showed important inter-individual differences in response for nicotine during the progressive ratio schedule of reinforcement. By comparing rats in the lower and upper quartiles of the mean breaking point, we showed that high-motivated rats were also more sensitive to the reinforcing properties of nicotine than low-motivated ones. We found that while both groups did not differ in premature responding in the FCN16cue task, high-motivated rats were more efficient in taking the cue light into account than low-motivated rats as shown by a higher proportion of optimal chains, indicating a higher level of attention to the reward-predictive cue. Moreover, it was positively correlated with higher motivation for nicotine, a hallmark of nicotine addiction. CONCLUSIONS These results suggest that higher attention to reward-associated cues prior to drug taking predicts vulnerability to nicotine-reinforcing properties.
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Affiliation(s)
- Youna Vandaele
- Université de Bordeaux, Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, BP31, F-33076, Bordeaux, France.,Centre National de la Recherche Scientifique, UMR 5287-Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, F-33076, Bordeaux, France
| | - Emilie Noe
- Université de Bordeaux, Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, BP31, F-33076, Bordeaux, France.,Centre National de la Recherche Scientifique, UMR 5287-Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, F-33076, Bordeaux, France
| | - Martine Cador
- Université de Bordeaux, Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, BP31, F-33076, Bordeaux, France.,Centre National de la Recherche Scientifique, UMR 5287-Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, F-33076, Bordeaux, France
| | - Françoise Dellu-Hagedorn
- Université de Bordeaux, Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, BP31, F-33076, Bordeaux, France. .,Centre National de la Recherche Scientifique, UMR 5287-Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, F-33076, Bordeaux, France.
| | - Stephanie Caille
- Université de Bordeaux, Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, BP31, F-33076, Bordeaux, France. .,Centre National de la Recherche Scientifique, UMR 5287-Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, F-33076, Bordeaux, France.
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18
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Fiorenza AM, Shnitko TA, Sullivan KM, Vemuru SR, Gomez-A A, Esaki JY, Boettiger CA, Da Cunha C, Robinson DL. Ethanol Exposure History and Alcoholic Reward Differentially Alter Dopamine Release in the Nucleus Accumbens to a Reward-Predictive Cue. Alcohol Clin Exp Res 2018; 42:1051-1061. [PMID: 29602178 DOI: 10.1111/acer.13636] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 03/18/2018] [Indexed: 11/27/2022]
Abstract
BACKGROUND Conditioned stimuli (CS) that predict reward delivery acquire the ability to induce phasic dopamine release in the nucleus accumbens (NAc). This dopamine release may facilitate conditioned approach behavior, which often manifests as approach to the site of reward delivery (called "goal-tracking") or to the CS itself (called "sign-tracking"). Previous research has linked sign-tracking in particular to impulsivity and drug self-administration, and addictive drugs may promote the expression of sign-tracking. Ethanol (EtOH) acutely promotes phasic release of dopamine in the accumbens, but it is unknown whether an alcoholic reward alters dopamine release to a CS. We hypothesized that Pavlovian conditioning with an alcoholic reward would increase dopamine release triggered by the CS and subsequent sign-tracking behavior. Moreover, we predicted that chronic intermittent EtOH (CIE) exposure would promote sign-tracking while acute administration of naltrexone (NTX) would reduce it. METHODS Rats received 14 doses of EtOH (3 to 5 g/kg, intragastric) or water followed by 6 days of Pavlovian conditioning training. Rewards were a chocolate solution with or without 10% (w/v) alcohol. We used fast-scan cyclic voltammetry to measure phasic dopamine release in the NAc core in response to the CS and the rewards. We also determined the effect of NTX (1 mg/kg, subcutaneous) on conditioned approach. RESULTS Both CIE and alcoholic reward, individually but not together, associated with greater dopamine to the CS than control conditions. However, this increase in dopamine release was not linked to greater sign-tracking, as both CIE and alcoholic reward shifted conditioned approach from sign-tracking behavior to goal-tracking behavior. However, they both also increased sensitivity to NTX, which reduced goal-tracking behavior. CONCLUSIONS While a history of EtOH exposure or alcoholic reward enhanced dopamine release to a CS, they did not promote sign-tracking under the current conditions. These findings are consistent with the interpretation that EtOH can stimulate conditioned approach, but indicate that the conditioned response may manifest as goal-tracking.
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Affiliation(s)
- Amanda M Fiorenza
- Departamento de Bioquímica, Universidade Federal do Paraná, Curitiba, Paraná, Brazil
| | - Tatiana A Shnitko
- Department of Psychiatry and Bowles Center for Alcohol Studies, University of North Carolina, Chapel Hill, North Carolina
| | - Kaitlin M Sullivan
- Department of Psychiatry and Bowles Center for Alcohol Studies, University of North Carolina, Chapel Hill, North Carolina
| | - Sudheer R Vemuru
- Department of Psychiatry and Bowles Center for Alcohol Studies, University of North Carolina, Chapel Hill, North Carolina
| | - Alexander Gomez-A
- Departamento de Farmacologia, Universidade Federal do Paraná, Curitiba, Paraná, Brazil
| | - Julie Y Esaki
- Departamento de Farmacologia, Universidade Federal do Paraná, Curitiba, Paraná, Brazil
| | - Charlotte A Boettiger
- Department of Psychology & Neuroscience, Bowles Center for Alcohol Studies and Biomedical Research Imaging Center, University of North Carolina, Chapel Hill, North Carolina
| | - Claudio Da Cunha
- Departamento de Bioquímica, Universidade Federal do Paraná, Curitiba, Paraná, Brazil.,Departamento de Farmacologia, Universidade Federal do Paraná, Curitiba, Paraná, Brazil
| | - Donita L Robinson
- Department of Psychiatry and Bowles Center for Alcohol Studies, University of North Carolina, Chapel Hill, North Carolina
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19
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Overby PF, Daniels CW, Del Franco A, Goenaga J, Powell GL, Gipson CD, Sanabria F. Effects of nicotine self-administration on incentive salience in male Sprague Dawley rats. Psychopharmacology (Berl) 2018; 235:1121-1130. [PMID: 29374305 DOI: 10.1007/s00213-018-4829-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2017] [Accepted: 01/03/2018] [Indexed: 12/26/2022]
Abstract
RATIONALE Prolonged use of nicotine appears to enhance incentive salience, a motivational-cognitive process that transforms an otherwise neutral stimulus into a "wanted" stimulus. It has been suggested that nicotinic enhancement of incentive salience contributes to the potential of relapse in individuals with tobacco addiction. However, there are two main limitations of prior research that caution this claim: (a) the use of passive experimentally delivered nicotine and (b) the use of sign-tracking as an index of incentive salience, without acknowledging the competing nature of goal- and sign-tracking responses. OBJECTIVES To determine whether nicotinic enhancement of incentive salience attributed to non-nicotinic stimuli occurs when rats self-administer nicotine, and whether it is facilitated by a prior history of nicotine self-administration. METHODS Twenty-three male rats were trained daily, for 24 days, on a nicotine self-administration (SA) paradigm in the morning, and on a four-conditioned-stimuli Pavlovian conditioned approach (4-CS PCA) task in the afternoon. Self-administration was followed by extinction and cue reinstatement. A subcutaneous nicotine challenge was performed during the last 7 days of the study. RESULTS Nicotine self-administration selectively enhanced sign-tracking in the 4-CS PCA. Upon extinction, sign-tracking quickly declined to control levels. Experimenter-administered nicotine enhanced sign-tracking similarly regardless of nicotine history. CONCLUSIONS The results suggest that nicotinic enhancement of incentive salience is transient, and a previous history of nicotine use does not cause further sensitization. Taken together, these results suggest that nicotine enhances incentive salience, particularly-and perhaps exclusively-while onboard.
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Affiliation(s)
- Paula F Overby
- Department of Psychology, Arizona State University, P.O. Box 871104, Tempe, AZ, 85287-1104, USA
| | - Carter W Daniels
- Department of Psychology, Arizona State University, P.O. Box 871104, Tempe, AZ, 85287-1104, USA
| | - Armani Del Franco
- School of Life Sciences, Arizona State University, P.O. Box 871104, Tempe, AZ, 85287-1104, USA
| | - Julianna Goenaga
- Department of Psychology, Arizona State University, P.O. Box 871104, Tempe, AZ, 85287-1104, USA
| | - Gregory L Powell
- Department of Psychology, Arizona State University, P.O. Box 871104, Tempe, AZ, 85287-1104, USA
- School of Life Sciences, Arizona State University, P.O. Box 871104, Tempe, AZ, 85287-1104, USA
| | - Cassandra D Gipson
- Department of Psychology, Arizona State University, P.O. Box 871104, Tempe, AZ, 85287-1104, USA
| | - Federico Sanabria
- Department of Psychology, Arizona State University, P.O. Box 871104, Tempe, AZ, 85287-1104, USA.
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20
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Zhou Y, Li C, Li R, Zhou C. Exercise improves nicotine reward‐associated cognitive behaviors and related α7 nAChR‐mediated signal transduction in adolescent rats. J Cell Physiol 2018; 233:5756-5767. [DOI: 10.1002/jcp.26295] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 10/04/2017] [Indexed: 11/06/2022]
Affiliation(s)
- Yuehui Zhou
- School of Sport ScienceQufu Normal UniversityShandongChina
| | - Cuicui Li
- Department of Sport PsychologySchool of Sport Science, Shanghai University of SportShanghaiChina
| | - Rena Li
- Department of Sport PsychologySchool of Sport Science, Shanghai University of SportShanghaiChina
- Center for Hormone Advanced Science and EducationRoskamp InstituteSarasotaFlorida
| | - Chenglin Zhou
- Department of Sport PsychologySchool of Sport Science, Shanghai University of SportShanghaiChina
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21
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Romero K, Daniels CW, Gipson CD, Sanabria F. Suppressive and enhancing effects of nicotine on food-seeking behavior. Behav Brain Res 2018; 339:130-139. [PMID: 29175447 PMCID: PMC5736011 DOI: 10.1016/j.bbr.2017.11.023] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Revised: 11/10/2017] [Accepted: 11/17/2017] [Indexed: 12/14/2022]
Abstract
The present study examined how systemic low doses of nicotine affect the microstructure of reinforced food-seeking behavior in rats. Rats were first given an acute saline or nicotine treatment (0.1-0.6mg/kg, with an inter-injection interval of at least 48h), and then a chronic saline or nicotine treatment (0.3mg/kg/day for 10 consecutive days). Immediately after each injection, rats were required to press a lever five times to obtain food that was available at unpredictable times (on average every 80s) with constant probability. Acute nicotine dose-dependently suppressed behavior prior to the delivery of the first reinforcer, but enhanced food-reinforced behavior afterwards. These effects were primarily observed in the time it took rats to initiate food-seeking behavior. Enhancing effects were also observed in the microstructure of food-seeking behavior, with lower nicotine doses (0.1-0.3mg/kg) increasing the rate at which response bouts were initiated, and higher doses (0.3-0.6mg/kg) increasing within-bout response rates. A pre-feeding control suggests that changes in appetite alone cannot explain these effects. Over the course of chronic nicotine exposure, tolerance developed to the suppressive, but not to the enhancing effects of nicotine on food-seeking behavior. These results suggest that (a) lower doses of nicotine enhance the reward value of food and/or food-associated stimuli, (b) higher doses of nicotine enhance motoric activity, and (c) ostensive sensitization effects of nicotine on behavior partially reflect a tolerance to its transient suppressive motoric effects.
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22
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Stringfield SJ, Boettiger CA, Robinson DL. Nicotine-enhanced Pavlovian conditioned approach is resistant to omission of expected outcome. Behav Brain Res 2018; 343:16-20. [PMID: 29407412 DOI: 10.1016/j.bbr.2018.01.023] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Revised: 01/18/2018] [Accepted: 01/19/2018] [Indexed: 11/30/2022]
Abstract
Conditioned stimuli contribute to the resilience of nicotine addiction in that nicotine-associated cues can influence smokers and promote relapse. These stimuli are thought to acquire incentive motivational properties through a Pavlovian mechanism, and this phenomenon can be measured in animals by observing conditioned approach to the conditioned stimulus (sign-tracking) or to the location of unconditioned stimulus delivery (goal-tracking). Goal-tracking is thought to be more flexible than sign-tracking in response to changes in expected outcome. Nicotine exposure can increase the expression of conditioned responses, and we hypothesized that animals exposed to nicotine would also exhibit less flexible conditioned responses after a change in the expected unconditioned stimulus. Adult male rats were exposed to nicotine (0.4mg/kg, s.c.) or saline before Pavlovian conditioned approach training sessions. After training, animals underwent test sessions that reduced (water substitution) or withheld (omission) the unconditioned stimulus (US, 20% sucrose). As expected, nicotine enhanced sign- and goal-tracking. Water substitution moderately and nonspecifically reduced both sign- and goal-tracking in all rats. In contrast, US omission only reduced goal-tracking, with robust effects in saline-exposed rats and smaller effects in nicotine-exposed rats. These data support the hypothesis that both sign-tracking and nicotine exposure confer behavioral inflexibility under US omission.
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Affiliation(s)
- Sierra J Stringfield
- Bowles Center for Alcohol Studies, University of North Carolina, Chapel Hill, NC, USA; Neuroscience Curriculum, University of North Carolina, Chapel Hill, NC, USA
| | - Charlotte A Boettiger
- Bowles Center for Alcohol Studies, University of North Carolina, Chapel Hill, NC, USA; Neuroscience Curriculum, University of North Carolina, Chapel Hill, NC, USA; Department of Psychology and Neuroscience, University of North Carolina, Chapel Hill, NC, USA
| | - Donita L Robinson
- Bowles Center for Alcohol Studies, University of North Carolina, Chapel Hill, NC, USA; Neuroscience Curriculum, University of North Carolina, Chapel Hill, NC, USA; Department of Psychiatry, University of North Carolina, Chapel Hill, NC, USA.
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23
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Madayag AC, Czarnecki KS, Wangler LM, Robinson DL. Chronic Nicotine Exposure Initiated in Adolescence and Unpaired to Behavioral Context Fails to Enhance Sweetened Ethanol Seeking. Front Behav Neurosci 2017; 11:153. [PMID: 28860980 PMCID: PMC5562684 DOI: 10.3389/fnbeh.2017.00153] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2017] [Accepted: 08/02/2017] [Indexed: 01/01/2023] Open
Abstract
Nicotine use in adolescence is pervasive in the United States and, according to the Gateway Hypothesis, may lead to progression towards other addictive substances. Given the prevalence of nicotine and ethanol comorbidity, it is difficult to ascertain if nicotine is a gateway drug for ethanol. Our study investigated the relationship between adolescent exposure to nicotine and whether this exposure alters subsequent alcohol seeking behavior. We hypothesized that rats exposed to nicotine beginning in adolescence would exhibit greater alcohol seeking behavior than non-exposed siblings. To test our hypothesis, beginning at P28, female rats were initially exposed to once daily nicotine (0.4 mg/kg, SC) or saline for 5 days. Following these five initial injections, animals were trained to nose-poke for sucrose reinforcement (10%, w/v), gradually increasing to sweetened ethanol (10% sucrose; 10% ethanol, w/v) on an FR5 reinforcement schedule. Nicotine injections were administered after the behavioral sessions to minimize acute effects of nicotine on operant self-administration. We measured the effects of nicotine exposure on the following aspects of ethanol seeking: self-administration, naltrexone (NTX)-induced decreases, habit-directed behavior, motivation, extinction and reinstatement. Nicotine exposure did not alter self-administration or the effectiveness of NTX to reduce alcohol seeking. Nicotine exposure blocked habit-directed ethanol seeking. Finally, nicotine did not alter extinction learning or cue-induced reinstatement to sweetened ethanol seeking. Our findings suggest that nicotine exposure outside the behavioral context does not escalate ethanol seeking. Further, the Gateway Hypothesis likely applies to scenarios in which nicotine is either self-administered or physiologically active during the behavioral session.
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Affiliation(s)
- Aric C Madayag
- Bowles Center for Alcohol Studies, University of North CarolinaChapel Hill, NC, United States.,Department of Pharmacology, University of North CarolinaChapel Hill, NC, United States
| | - Kyle S Czarnecki
- Bowles Center for Alcohol Studies, University of North CarolinaChapel Hill, NC, United States
| | - Lynde M Wangler
- Bowles Center for Alcohol Studies, University of North CarolinaChapel Hill, NC, United States
| | - Donita L Robinson
- Bowles Center for Alcohol Studies, University of North CarolinaChapel Hill, NC, United States.,Department of Psychiatry, University of North CarolinaChapel Hill, NC, United States
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24
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Stringfield SJ, Palmatier MI, Boettiger CA, Robinson DL. Orbitofrontal participation in sign- and goal-tracking conditioned responses: Effects of nicotine. Neuropharmacology 2017; 116:208-223. [PMID: 28012948 PMCID: PMC5385154 DOI: 10.1016/j.neuropharm.2016.12.020] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Revised: 11/15/2016] [Accepted: 12/21/2016] [Indexed: 11/22/2022]
Abstract
Pavlovian conditioned stimuli can acquire incentive motivational properties, and this phenomenon can be measured in animals using Pavlovian conditioned approach behavior. Drugs of abuse can influence the expression of this behavior, and nicotine in particular exhibits incentive amplifying effects. Both conditioned approach behavior and drug abuse rely on overlapping corticolimbic circuitry. We hypothesize that the orbitofrontal cortex (OFC) regulates conditioned approach, and that one site of nicotine action is in the OFC where it reduces cortical output. To test this, we repeatedly exposed rats to 0.4 mg/kg nicotine (s.c.) during training and then pharmacologically inactivated the lateral OFC or performed in vivo electrophysiological recordings of lateral OFC neurons in the presence or absence of nicotine. In Experiment 1, animals were trained in a Pavlovian conditioning paradigm and behavior was evaluated after inactivation of the OFC by microinfusion of the GABA agonists baclofen and muscimol. In Experiment 2, we monitored phasic firing of OFC neurons during Pavlovian conditioning sessions. Nicotine reliably enhanced conditioned responding to the conditioned cue, and inactivation of the OFC reduced conditioned responding, especially the sign-tracking response. OFC neurons exhibited phasic excitations to cue presentation and during goal tracking, and nicotine acutely blunted this phasic neuronal firing. When nicotine was withheld, both conditioned responding and phasic firing in the OFC returned to the level of controls. These results suggest that the OFC is recruited for the expression of conditioned responses, and that nicotine acutely influences this behavior by reducing phasic firing in the OFC.
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Affiliation(s)
- Sierra J Stringfield
- Bowles Center for Alcohol Studies, University of North Carolina, Chapel Hill, NC, USA; Neurobiology Curriculum, University of North Carolina, Chapel Hill, NC, USA
| | - Matthew I Palmatier
- Department of Psychology, East Tennessee State University, Johnson City, TN, USA
| | - Charlotte A Boettiger
- Bowles Center for Alcohol Studies, University of North Carolina, Chapel Hill, NC, USA; Neurobiology Curriculum, University of North Carolina, Chapel Hill, NC, USA; Department of Psychology and Neuroscience, University of North Carolina, Chapel Hill, NC, USA
| | - Donita L Robinson
- Bowles Center for Alcohol Studies, University of North Carolina, Chapel Hill, NC, USA; Neurobiology Curriculum, University of North Carolina, Chapel Hill, NC, USA; Department of Psychiatry, University of North Carolina, Chapel Hill, NC, USA.
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Madayag AC, Stringfield SJ, Reissner KJ, Boettiger CA, Robinson DL. Sex and Adolescent Ethanol Exposure Influence Pavlovian Conditioned Approach. Alcohol Clin Exp Res 2017; 41:846-856. [PMID: 28196273 DOI: 10.1111/acer.13354] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Accepted: 02/08/2017] [Indexed: 01/03/2023]
Abstract
BACKGROUND Alcohol use among adolescents is widespread and a growing concern due to long-term behavioral deficits, including altered Pavlovian behavior, that potentially contribute to addiction vulnerability. We tested the hypothesis that adolescent intermittent ethanol (AIE) exposure alters Pavlovian behavior in males and females as measured by a shift from goal-tracking to sign-tracking. Additionally, we investigated GLT-1, an astrocytic glutamate transporter, as a potential contributor to a sign-tracking phenotype. METHODS Male and female Sprague-Dawley rats were exposed to AIE (5 g/kg, intragastric) or water intermittently 2 days on and 2 days off from postnatal day (P) 25 to 54. Around P70, animals began 20 daily sessions of Pavlovian conditioned approach (PCA), where they learned that a cue predicted noncontingent reward delivery. Lever pressing indicated interaction with the cue, or sign-tracking, and receptacle entries indicated approach to the reward delivery location, or goal-tracking. To test for effects of AIE on nucleus accumbens (NAcc) excitatory signaling, we isolated membrane subfractions and measured protein levels of the glutamate transporter GLT-1 after animals completed behavior as a measure of glutamate homeostasis. RESULTS Females exhibited elevated sign-tracking compared to males with significantly more lever presses, faster latency to first lever press, and greater probability to lever press in a trial. AIE significantly increased lever pressing while blunting goal-tracking, as indicated by fewer cue-evoked receptacle entries, slower latency to receptacle entry, and lower probability to enter the receptacle in a trial. No significant sex-by-exposure interactions were observed in sign- or goal-tracking metrics. Moreover, we found no significant effects of sex or exposure on membrane GLT-1 expression in the NAcc. CONCLUSIONS Females exhibited enhanced sign-tracking compared to males, while AIE decreased goal-tracking compared to control exposure. Our findings support the hypothesis that adolescent binge ethanol can shift conditioned behavior from goal- to cue-directed in PCA, especially in females.
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Affiliation(s)
- Aric C Madayag
- Bowles Center for Alcohol Studies, University of North Carolina, Chapel Hill, North Carolina.,Department of Pharmacology, University of North Carolina, Chapel Hill, North Carolina
| | - Sierra J Stringfield
- Bowles Center for Alcohol Studies, University of North Carolina, Chapel Hill, North Carolina.,Neurobiology Curriculum, University of North Carolina, Chapel Hill, North Carolina
| | - Kathryn J Reissner
- Neurobiology Curriculum, University of North Carolina, Chapel Hill, North Carolina.,Department of Psychology and Neuroscience, University of North Carolina, Chapel Hill, North Carolina
| | - Charlotte A Boettiger
- Bowles Center for Alcohol Studies, University of North Carolina, Chapel Hill, North Carolina.,Neurobiology Curriculum, University of North Carolina, Chapel Hill, North Carolina.,Department of Psychology and Neuroscience, University of North Carolina, Chapel Hill, North Carolina
| | - Donita L Robinson
- Bowles Center for Alcohol Studies, University of North Carolina, Chapel Hill, North Carolina.,Neurobiology Curriculum, University of North Carolina, Chapel Hill, North Carolina.,Department of Psychiatry, University of North Carolina, Chapel Hill, North Carolina
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Nicotine-induced enhancement of Pavlovian alcohol-seeking behavior in rats. Psychopharmacology (Berl) 2017; 234:727-738. [PMID: 28011981 DOI: 10.1007/s00213-016-4508-2] [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: 09/20/2016] [Accepted: 12/09/2016] [Indexed: 01/02/2023]
Abstract
RATIONALE Nicotine enhances responding elicited by Pavlovian cues that predict positive outcomes. OBJECTIVES We tested the hypothesis that nicotine acting at nicotinic acetylcholine receptors (nAChRs) would augment Pavlovian alcohol-seeking. METHODS Male, Long-Evans rats with unrestricted access to food and water were acclimated to drinking 15% ethanol in their home cages and then given Pavlovian conditioning sessions in which each trial of a 15-s conditioned stimulus (CS, 12 trials/session) was paired with 0.2 ml of ethanol (unconditioned stimulus, US, 2.4 ml/session). Entries into a port where ethanol was delivered were used to assess conditioning. Control groups received explicitly unpaired trials of the CS and US. In experiment 1, systemic injections of saline (1 ml/kg) or nicotine (0.4 mg/kg, freebase) were administered before each session. In experiments 2 and 3, an identical regimen of saline or nicotine injections was administered before the start of Pavlovian conditioning sessions. RESULTS All paired groups acquired conditioned port-entry responding to the CS, indicative of Pavlovian alcohol-seeking, whereas unpaired control group did not. Pre-session nicotine injections increased CS port-entries relative to saline, only in the paired group. This nicotine-induced enhancement of Pavlovian alcohol-seeking was blocked by pre-treatment with the nAChR antagonist mecamylamine. Prior exposure to nicotine did not influence the subsequent acquisition of Pavlovian alcohol-seeking. CONCLUSIONS These findings highlight for the first time that nicotine acting at nAChRs augments Pavlovian alcohol-seeking, specifically in non-restricted rats. Individuals who smoke and drink may thus be particularly susceptible to alcohol cues that could trigger further drinking.
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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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Villaruel FR, Chaudhri N. Individual Differences in the Attribution of Incentive Salience to a Pavlovian Alcohol Cue. Front Behav Neurosci 2016; 10:238. [PMID: 28082877 PMCID: PMC5183577 DOI: 10.3389/fnbeh.2016.00238] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Accepted: 12/08/2016] [Indexed: 01/31/2023] Open
Abstract
Individual differences exist in the attribution of incentive salience to conditioned stimuli associated with food. Here, we investigated whether individual differences also manifested with a Pavlovian alcohol conditioned stimulus (CS). We compiled data from five experiments that used a Pavlovian autoshaping paradigm and tests of conditioned reinforcement. In all experiments, male, Long-Evans rats with unrestricted access to food and water were acclimated to 15% ethanol. Next, rats received Pavlovian autoshaping training, in which a 10 s presentation of a retractable lever served as the CS and 0.2 mL of 15% ethanol served as the unconditioned stimulus (US). Finally, rats underwent conditioned reinforcement tests in which nose-pokes to an active aperture led to brief presentations of the lever-CS, but nose-pokes to an inactive aperture had no consequence. Rats were categorized as sign-trackers, goal-trackers and intermediates based on a response bias score that reflected their tendencies to sign-track or goal-track at different times during training. We found that distinct groups of rats either consistently interacted with the lever-CS (“sign-trackers”) or routinely approached the port during the lever-CS (“goal-trackers”) across a majority of the training sessions. However, some individuals (“shifted sign-trackers”) with an early tendency to goal-track later shifted to comparable asymptotic levels of sign-tracking as the group identified as sign-trackers. The lever-CS functioned as a conditioned reinforcer for sign-trackers and shifted sign-trackers, but not for goal-trackers. These results provide evidence of robust individual differences in the extent to which a Pavlovian alcohol cue gains incentive salience and functions as a conditioned reinforcer.
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Affiliation(s)
- Franz R Villaruel
- Center for Studies in Behavioral Neurobiology/Groupe de Recherche en Neurobiologie Comportementale, Department of Psychology, Concordia University Montreal, QC, Canada
| | - Nadia Chaudhri
- Center for Studies in Behavioral Neurobiology/Groupe de Recherche en Neurobiologie Comportementale, Department of Psychology, Concordia University Montreal, QC, Canada
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The tendency to sign-track predicts cue-induced reinstatement during nicotine self-administration, and is enhanced by nicotine but not ethanol. Psychopharmacology (Berl) 2016; 233:2985-97. [PMID: 27282365 PMCID: PMC4935618 DOI: 10.1007/s00213-016-4341-7] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Accepted: 05/23/2016] [Indexed: 12/15/2022]
Abstract
RATIONALE Some individuals are particularly responsive to reward-associated stimuli ("cues"), including the effects of these cues on craving and relapse to drug-seeking behavior. In the cases of nicotine and alcohol, cues may acquire these abilities via the incentive-enhancing properties of the drug. OBJECTIVES To determine the interaction between cue-responsivity and nicotine reinforcement, we studied the patterns of nicotine self-administration in rats categorized based on their tendency to approach a food-predictive cue ("sign-trackers") or a reward-delivery location ("goal-trackers"). In a second experiment, we determined whether nicotine and ethanol altered the incentive value of a food cue. METHODS Rats were classified as sign- or goal-trackers during a Pavlovian conditioned approach paradigm. Rats then self-administered intravenous nicotine (0.03 mg/kg infusions) followed by extinction and cue-induced reinstatement tests. We also tested the effects of nicotine (0.4 mg/kg base s.c.) or ethanol (0.7 g/kg i.p.) on the approach to, and reinforcing efficacy of, a food cue. RESULTS Sign-trackers showed greater reinstatement in response to a nicotine cue. Further, nicotine enhanced sign-tracking but not goal-tracking to a food cue and also enhanced responding for the food cue during the conditioned reinforcement test. Conversely, ethanol reduced sign-tracking and increased goal-tracking, but had no effect on conditioned reinforcement. CONCLUSIONS Our studies demonstrate that the tendency to attribute incentive value to a food cue predicts enhanced cue-induced reinstatement. Additionally, the incentive value of food cues is differentially modulated by nicotine and ethanol, which may be related to the reinforcing effects of these drugs.
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Diminished Dopamine: Timing, Neuroanatomy, or Drug History? J Neurosci 2016; 36:4907-9. [PMID: 27147645 DOI: 10.1523/jneurosci.0731-16.2016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2016] [Accepted: 03/30/2016] [Indexed: 11/21/2022] Open
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Yager LM, Robinson TE. Individual variation in the motivational properties of a nicotine cue: sign-trackers vs. goal-trackers. Psychopharmacology (Berl) 2015; 232:3149-60. [PMID: 25980485 PMCID: PMC4536151 DOI: 10.1007/s00213-015-3962-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Accepted: 05/08/2015] [Indexed: 12/26/2022]
Abstract
RATIONALE Individuals vary in the extent to which they attribute incentive salience to reward cues. Discrete food and drug (cocaine and opioid) cues become more attractive, eliciting approach toward them, and more "wanted," in that they serve as more effective conditioned reinforcers, in some rats (sign-trackers, STs), than in others (goal-trackers, GTs). OBJECTIVES We asked whether there is similar variation in the extent to which a cue associated with a drug from another class, nicotine, acquires incentive motivational properties. METHODS First, a Pavlovian conditioned approach procedure was used to identify rats that attribute incentive salience to a food cue (i.e., STs and GTs). We then measured the extent to which a cue (a light) paired with intravenous nicotine injections acquired two properties of an incentive stimulus: (1) the ability to elicit approach toward it, and (2) the ability to act as a conditioned reinforcer. RESULTS In contrast to previous findings with food, cocaine, and opioid cues, we found that the nicotine cue was equally attractive in STs and GTs, eliciting dose-dependent approach behavior in both. However, the nicotine cue was a more effective conditioned reinforcer in STs than in GTs. CONCLUSIONS We suggest the dissociation between these two measures of incentive salience attribution may be related to the fact that when present (as in the test of Pavlovian approach), nicotine can act as a potent "incentive amplifier," and by this action, nicotine may render cues especially salient for all animals.
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Affiliation(s)
| | - Terry E. Robinson
- To whom correspondence should be addressed: Terry E. Robinson, Ph.D., Department of Psychology, University of Michigan, 530 Church St, East Hall, Ann Arbor, MI 48109, Tel.: +1 734 763 4361,
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Kirshenbaum A, Green J, Fay M, Parks A, Phillips J, Stone J, Roy T. Reinforcer devaluation as a consequence of acute nicotine exposure and withdrawal. Psychopharmacology (Berl) 2015; 232:1583-94. [PMID: 25401169 PMCID: PMC4397123 DOI: 10.1007/s00213-014-3792-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Accepted: 10/24/2014] [Indexed: 12/24/2022]
Abstract
RATIONALE Nicotine discontinuation produces behaviors in rats that are congruent with anhedonia, and these symptoms may be related to the devaluation of non-nicotine reinforcers. OBJECTIVE Four separate experiments were performed to explore the parameters surrounding nicotine-induced reinforcer devaluation. METHODS In Experiments 1 and 2, nicotine (0.1 or 0.3 mg/kg) or 0.3 mg/kg nicotine plus 1.0 mg/kg mecamylamine was delivered to rats prior to progressive ratio (PR) schedule sessions in which sucrose was used as a reinforcer. In order to evaluate (a) reinforcer enhancement by nicotine and (b) reinforcer devaluation in the absence of nicotine, all rats experienced two PR schedule sessions per day for 10 days. Experiment 3 involved nicotine (0.3 mg/kg) and a visual stimulus in place of sucrose reinforcement. In Experiment 4, rats received nicotine (0.3 mg/kg) either before or after a single PR schedule session for 10 days. RESULTS Experiments 1 and 2 demonstrate that reinforcer devaluation is related to the occupation of nicotinic-acetylcholine receptors. Results from Experiment 3 provide some evidence that devaluation occurs with either sucrose or visual-stimulus reinforcement. Experiment 4 demonstrates that a necessary condition for reinforcer devaluation to occur is the concurrent exposure to the reinforcer and nicotine. CONCLUSIONS Reinforcer devaluation in rats emerges rapidly in a progressive, orderly fashion that coincides with accumulated exposure to nicotine. These results suggest that reinforcer devaluation may be a feature of nicotine that contributes to the abuse liability of tobacco products.
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Affiliation(s)
- Ari Kirshenbaum
- Department of Psychology, Saint Michael's College, 1 Winooski Park Avenue, Colchester, VT, 05439-0001, USA,
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High locomotor reactivity to novelty is associated with an increased propensity to choose saccharin over cocaine: new insights into the vulnerability to addiction. Neuropsychopharmacology 2015; 40:577-89. [PMID: 25120076 PMCID: PMC4289945 DOI: 10.1038/npp.2014.204] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2014] [Revised: 07/22/2014] [Accepted: 07/31/2014] [Indexed: 11/08/2022]
Abstract
Drug addiction is associated with a relative devaluation of natural or socially-valued reinforcers that are unable to divert addicts from seeking and consuming the drug. Before protracted drug exposure, most rats prefer natural rewards, such as saccharin, over cocaine. However, a subpopulation of animals prefer cocaine over natural rewards and are thought to be vulnerable to addiction. Specific behavioral traits have been associated with different dimensions of drug addiction. For example, anxiety predicts loss of control over drug intake whereas sensation seeking and sign-tracking are markers of a greater sensitivity to the rewarding properties of the drug. However, how these behavioral traits predict the disinterest for natural reinforcers remains unknown. In a population of rats, we identified sensation seekers (HR) on the basis of elevated novelty-induced locomotor reactivity, high anxious rats (HA) based on the propensity to avoid open arms in an elevated-plus maze and sign-trackers (ST) that are prone to approach, and interaction with, reward-associated stimuli. Rats were then tested on their preference for saccharin over cocaine in a discrete-trial choice procedure. We show that HR rats display a greater preference for saccharin over cocaine compared with ST and HA whereas the motivation for the drug was comparable between the three groups. The present data suggest that high locomotor reactivity to novelty, or sensation seeking, by predisposing to an increased choice toward non-drug rewards at early stages of drug use history, may prevent the establishment of chronic cocaine use.
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Palmatier MI, Kellicut MR, Brianna Sheppard A, Brown RW, Robinson DL. The incentive amplifying effects of nicotine are reduced by selective and non-selective dopamine antagonists in rats. Pharmacol Biochem Behav 2014; 126:50-62. [PMID: 25230311 PMCID: PMC4440414 DOI: 10.1016/j.pbb.2014.08.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Revised: 08/18/2014] [Accepted: 08/24/2014] [Indexed: 01/18/2023]
Abstract
Nicotine is a psychomotor stimulant with 'reinforcement enhancing' effects--the actions of nicotine in the brain increase responding for non-nicotine rewards. We hypothesized that this latter effect of nicotine depends on increased incentive properties of anticipatory cues; consistent with this hypothesis, multiple laboratories have reported that nicotine increases sign tracking, i.e. approach to a conditioned stimulus (CS), in Pavlovian conditioned-approach tasks. Incentive motivation and sign tracking are mediated by mesolimbic dopamine (DA) transmission and nicotine facilitates mesolimbic DA release. Therefore, we hypothesized that the incentive-promoting effects of nicotine would be impaired by DA antagonists. To test this hypothesis, separate groups of rats were injected with nicotine (0.4mg/kg base) or saline prior to Pavlovian conditioning sessions in which a CS (30s illumination of a light or presentation of a lever) was immediately followed by a sweet reward delivered in an adjacent location. Both saline and nicotine pretreated rats exhibited similar levels of conditioned approach to the reward location (goal tracking), but nicotine pretreatment significantly increased approach to the CS (sign tracking), regardless of type (lever or light). The DAD1 antagonist SCH-23390 and the DAD2/3 antagonist eticlopride reduced conditioned approach in all rats, but specifically reduced goal tracking in the saline pretreated rats and sign tracking in the nicotine pretreated rats. The non-selective DA antagonist flupenthixol reduced sign-tracking in nicotine rats at all doses tested; however, only the highest dose of flupenthixol reduced goal tracking in both nicotine and saline groups. The reductions in conditioned approach behavior, especially those by SCH-23390, were dissociated from simple motor suppressant effects of the antagonists. These experiments are the first to investigate the effects of dopaminergic drugs on the facilitation of sign-tracking engendered by nicotine and they implicate dopaminergic systems both in conditioned approach as well as the incentive-promoting effects of nicotine.
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Affiliation(s)
- Matthew I Palmatier
- Department of Psychology, East Tennessee State University, Johnson City, TN 37641, USA.
| | - Marissa R Kellicut
- Department of Psychology, East Tennessee State University, Johnson City, TN 37641, USA
| | - A Brianna Sheppard
- Department of Psychology, East Tennessee State University, Johnson City, TN 37641, USA
| | - Russell W Brown
- Department of Psychology, East Tennessee State University, Johnson City, TN 37641, USA
| | - Donita L Robinson
- Bowles Center for Alcohol Studies, Department of Psychiatry, University of North Carolina, Chapel Hill, NC 27599, USA
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Meyer PJ, Cogan ES, Robinson TE. The form of a conditioned stimulus can influence the degree to which it acquires incentive motivational properties. PLoS One 2014; 9:e98163. [PMID: 24905195 PMCID: PMC4048203 DOI: 10.1371/journal.pone.0098163] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Accepted: 04/29/2014] [Indexed: 11/19/2022] Open
Abstract
There is considerable individual variation in the extent to which food- and drug-associated cues (conditioned stimuli, CSs) acquire incentive salience, as indicated by whether they elicit approach towards them, and/or act as conditioned reinforcers. Here we asked whether this variation is influenced by properties of the CS itself. In rats, we assessed both the attractiveness and conditioned reinforcing properties of two CSs: a manipulable lever CS versus an auditory (tone) CS. There was considerable individual variation in the extent to which a lever CS acquired incentive motivational properties, as indicated by whether it became attractive (evoked a sign-tracking or goal-tracking conditioned response) or acted as a conditioned reinforcer. However, with a tone CS all rats learned a goal-tracking response, and the tone CS was an equally effective conditioned reinforcer in sign-trackers and goal-trackers. Even when presented in compound (a lever-tone CS), the two elements of the compound differentially acquired motivational properties. In contrast, amphetamine and stress potentiated the conditioned reinforcing properties of both visual and auditory CSs similarly in rats that primarily sign-tracked or goal-tracked. We conclude that variation in the to the ability of CSs to acquire incentive salience, and thus their ability to act as incentive stimuli capable of motivating behavior, is determined in part by properties of the CS itself.
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Affiliation(s)
- Paul J. Meyer
- Department of Psychology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Elizabeth S. Cogan
- Department of Psychology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Terry E. Robinson
- Department of Psychology, University of Michigan, Ann Arbor, Michigan, United States of America
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The effects of nicotine exposure during Pavlovian conditioning in rats on several measures of incentive motivation for a conditioned stimulus paired with water. Psychopharmacology (Berl) 2014; 231:2261-71. [PMID: 24317443 DOI: 10.1007/s00213-013-3375-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2013] [Accepted: 11/24/2013] [Indexed: 12/26/2022]
Abstract
RATIONALE Nicotine enhances approach toward and operant responding for conditioned stimuli (CSs), but the effect of exposure during different phases of Pavlovian incentive learning on these measures remains to be determined. OBJECTIVES These studies examined the effects of administering nicotine early, late or throughout Pavlovian conditioning trials on discriminated approach behavior, nicotine-enhanced responding for conditioned reinforcement, extinction, and the reinstatement of responding for conditioned reinforcement. We also tested the effect of nicotine on approach to a lever-CS in a Pavlovian autoshaping procedure and for this CS to serve as a conditioned reinforcer. METHODS Thirsty rats were exposed to 13 conditioning sessions where a light/tone CS was paired with the delivery of water. Nicotine was administered either prior to the first or last seven sessions, or throughout the entire conditioning procedure. Responding for conditioned reinforcement, extinction, and the reinstatement of responding by the stimulus and nicotine were compared across exposure groups. Separately, the effects of nicotine on conditioned approach toward a lever-CS during autoshaping, and responding for that CS as a conditioned reinforcer, were examined. RESULTS Nicotine exposure was necessary for nicotine-enhanced responding for conditioned reinforcement and the ability for nicotine and the stimulus to additively reinstate responding on the reinforced lever. Nicotine increased contacts with a lever-CS during autoshaping, and removal of nicotine abolished this effect. Prior nicotine exposure was necessary for nicotine-enhanced responding reinforced by the lever. CONCLUSIONS Enhancements in the motivating properties of CSs by nicotine occur independently from duration and timing effects of nicotine exposure during conditioning.
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Nicotine self-administration induces CB1-dependent LTP in the bed nucleus of the stria terminalis. J Neurosci 2014; 34:4285-92. [PMID: 24647948 DOI: 10.1523/jneurosci.3149-13.2014] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Nicotine addiction is characterized by repetitive drug taking and drug seeking, both tightly controlled by cannabinoid CB1 receptors. The responsiveness of neurons of the bed nucleus of the stria terminalis (BNST) to infralimbic cortex (ILCx) excitatory inputs is increased in rats with active, but not passive, nicotine taking. Therefore, we hypothesize that acquisition of the learned association between nicotine infusion and a paired cue light permits the strengthening of the ILCx-BNST synapses after ILCx tetanic stimulation. We exposed rats to intravenous nicotine self-administration for 2 months. Using a combination of in vivo protocols (electrical stimulations, extracellular recordings, and pharmacological manipulations), we characterized the effects of 10 Hz stimulation of the ILCx on BNST excitatory responses, under different conditions of exposure to nicotine. In addition, we tested whether the effects of the stimulation were CB1 receptor-dependent. The results show that nicotine self-administration supports the induction of evoked spike potentiation in the BNST in response to 10 Hz stimulation of ILCx afferents. Although not altered by nicotine abstinence, this cellular adaptation was blocked by CB1 receptor antagonism. Moreover, blockade of BNST CB1 receptors prevented increases in time-out responding subsequent to ILCx stimulation and decreased cue-induced reinstatement. Thus, the synaptic potentiation within the BNST in response to ILCx stimulation seems to contribute to the cue-elicited responding associated with nicotine self-administration and is tightly controlled by CB1 receptors.
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Saunders BT, Robinson TE. Individual variation in resisting temptation: implications for addiction. Neurosci Biobehav Rev 2013; 37:1955-75. [PMID: 23438893 PMCID: PMC3732519 DOI: 10.1016/j.neubiorev.2013.02.008] [Citation(s) in RCA: 114] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2012] [Revised: 01/28/2013] [Accepted: 02/12/2013] [Indexed: 11/29/2022]
Abstract
When exposed to the sights, sounds, smells and/or places that have been associated with rewards, such as food or drugs, some individuals have difficulty resisting the temptation to seek out and consume them. Others have less difficulty restraining themselves. Thus, Pavlovian reward cues may motivate maladaptive patterns of behavior to a greater extent in some individuals than in others. We are just beginning to understand the factors underlying individual differences in the extent to which reward cues acquire powerful motivational properties, and therefore, the ability to act as incentive stimuli. Here we review converging evidence from studies in both human and non-human animals suggesting that a subset of individuals are more "cue reactive", in that certain reward cues are more likely to attract these individuals to them and motivate actions to get them. We suggest that those individuals for whom Pavlovian reward cues become especially powerful incentives may be more vulnerable to impulse control disorders, such as binge eating and addiction.
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Affiliation(s)
| | - Terry E. Robinson
- Department of Psychology (Biopsychology Program), University of Michigan
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