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Mahmoudi S, Madden GJ. Using sign tracking to experimentally increase self-control in rats. J Exp Anal Behav 2024; 122:270-281. [PMID: 39406694 PMCID: PMC11570336 DOI: 10.1002/jeab.4211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Accepted: 08/27/2024] [Indexed: 11/19/2024]
Abstract
Impulsive choice describes a preference for a smaller-sooner reward (SSR) over a larger-later reward (LLR). A large body of research has examined different procedures for decreasing impulsive choice in nonhuman subjects. One limitation of these procedures is the extensive training duration required to achieve the desired results. To address this limitation, the current experiment examined the effects of a brief course of Pavlovian training, designed to establish a conditioned stimulus (CS) that could be strategically used to encourage LLR choices. Forty male Long-Evans rats were randomly assigned to appetitive Pavlovian or unpaired training. A lever insertion signaled an upcoming unconditioned stimulus (i.e., food presentation) for Pavlovian rats and it acquired CS properties. The lever was uncorrelated with the US in the unpaired group, and it did not acquire CS properties. In the subsequent impulsive-choice assessment, the lever from the training phase served as the lever rats pressed to choose the LLR. After an LLR choice, the lever remained in the chamber during the delay to the LLR, just as the SSR lever remained in the chamber until that reward was delivered. Pavlovian-trained rats sign tracked toward the lever CS and made significantly fewer impulsive choices than did rats in the unpaired group.
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Lamb RJ, Schindler CW, Ginsburg BC. Effects of an ethanol-paired conditioned stimulus on responding for ethanol suppressed by a conditioned-taste-aversion. Alcohol 2024; 116:1-8. [PMID: 37774959 DOI: 10.1016/j.alcohol.2023.09.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 09/25/2023] [Accepted: 09/26/2023] [Indexed: 10/01/2023]
Abstract
Ethanol-Paired Conditioned Stimuli (CS) can increase ethanol-responding either in extinction or occurring at low rates late in a session. To examine the generality of CS-induced increases in ethanol-responding, we examined whether a CS could increase responding suppressed by Conditioned-Taste-Aversion (CTA), which presumably suppresses responding by changing ethanol's valence from positive to negative. Rats were trained to respond for ethanol under a Random Interval (RI) schedule. We then removed the lever and paired Random-Time ethanol deliveries with illumination of a stimulus light (i.e., CS) for 10 sessions. Results were compared with a Truly Random Control group, in which the light and ethanol deliveries occurred independently. In a subsequent experiment, rats were treated similarly, except the light served as a discriminative stimulus, as the lever was extended and ethanol deliveries were available under a RI during light presentations. After this training, the lever was returned and rats again responded for ethanol. Subsequently, sessions were followed by LiCl administration. When responding reached low levels, LiCl administration stopped and the light was occasionally illuminated during the session. Responding during the light presentation was compared to responding during the period preceding light presentation. Responding partially recovered across 10 sessions and was greater during light presentations than in the period before it in all three groups. Increases were not reliably different between the groups, indicating that explanations for these increases such as CS-induced increases in motivation or approach toward the light are unlikely to be correct. The most likely explanation for these light-induced increases is that during sessions in which the light had been presented previously, LiCl had never been presented and thus, the light had come to signal that ethanol was safe to drink.
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Affiliation(s)
- R J Lamb
- Department of Psychiatry and Behavioral Sciences, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States.
| | - C W Schindler
- Designer Drug Unit, Intramural Research Program, National Institute on Drug Abuse, Baltimore, MD, United States
| | - Brett C Ginsburg
- Department of Psychiatry and Behavioral Sciences, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States
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AlTfaili H, Ginsburg BC, Lamb RJ. Ethanol-paired conditioned stimulus effects on concurrent reinforced responding for ethanol and food. Alcohol 2023; 111:17-23. [PMID: 36898642 PMCID: PMC10512455 DOI: 10.1016/j.alcohol.2023.02.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 02/09/2023] [Accepted: 02/27/2023] [Indexed: 03/11/2023]
Abstract
The influence of Pavlovian Conditioned Stimuli (CS) on ethanol self-administration and choice between ethanol and an alternative are potentially important. Ethanol-paired CS might increase ethanol self-administration, especially when it has been reduced during recovery, though the selectivity of these increases has been questioned. To date, one study examined the effects of an ethanol-paired CS on ethanol choice and found that the CS increased ethanol-responding more than food-responding when both were in extinction. However, it remains unclear whether ethanol-paired CS increase ethanol-choice that is not in extinction. Here, we examine the effects of an ethanol-paired CS on ethanol-choice when both food- and ethanol-responding are reinforced. Sixteen adult male Lewis rats were trained on a concurrent schedule to respond for ethanol on one lever and for food on the other lever. Ethanol was available under an FR 5 schedule, and food was available under an FR schedule that was adjusted for each rat to earn an equal number of food and ethanol deliveries. Then, 2-min light presentations were paired with an RT 25-sec schedule of ethanol delivery for 10 sessions in the absence of both levers. After this, subjects were placed back on the concurrent schedule for one session, then five sessions with the CS being present or absent on each trial of the concurrent schedule occurred. Rats learned to respond on one lever for ethanol and on the other for food and earned similar numbers of ethanol and food deliveries. During Pavlovian Conditioning, the number of head entries into the head-entry detector was higher in the presence of the CS than in its absence. In the test sessions, rats made more ethanol responses in the presence of the CS than in its absence. However, this effect was small and did not increase the amount of ethanol earned. Thus, ethanol-paired CS could increase ethanol-responding under a choice procedure but did not increase ethanol consumption meaningfully under the studied conditions.
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Affiliation(s)
- Hanana AlTfaili
- Department of Psychiatry and Behavioral Sciences, The University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Brett C Ginsburg
- Department of Psychiatry and Behavioral Sciences, The University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.
| | - R J Lamb
- Department of Psychiatry and Behavioral Sciences, The University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
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4
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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: 0.3] [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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Shields CN, Gremel CM. Prior chronic alcohol exposure enhances Pavlovian-to-instrumental transfer. Alcohol 2021; 96:83-92. [PMID: 34363928 DOI: 10.1016/j.alcohol.2021.07.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 06/29/2021] [Accepted: 07/26/2021] [Indexed: 12/25/2022]
Abstract
Alcohol dependence is associated with aberrant decision-making processes, particularly in the presence of alcohol-related environmental cues. For instance, alcohol cues can trigger alcohol seeking, consumption, and even relapse behavior. Recently, works have suggested that alcohol dependence may induce more general alterations in cued processes that support adaptive behavior, including enhanced cue control of volitional behavior unrelated to alcohol use. Here we examine this hypothesis by combining prior exposure to chronic intermittent ethanol and repeated withdrawal (CIE) procedures with a Pavlovian-to-instrumental transfer (PIT) task in mice. The PIT task entails training a Pavlovian association, separately training an instrumental contingency, and a final test during which the Pavlovian cue and instrumental action are combined for the first time. We first tested two variants of the PIT procedure in ethanol-naïve mice, differing in part in the duration of Pavlovian conditioned cues (short or long). We found in the PIT test that the short cue procedure produced negative transfer, whereas the long cue procedure produced positive transfer. We then used the long cue variant to examine PIT behavior in mice previously exposed to either CIE or air vapor. We found that prior CIE exposure strengthened PIT behavior, with enhanced instrumental responding during presentation of the food-associated cue. We further found that this enhancement in CIE mice persisted even after devaluation of the food outcome. Our findings suggest that ethanol dependence can enhance the influence of reward-predictive cues on ongoing behavior. Greater non-alcohol cue control of behavior may reflect the effect of chronic ethanol exposure on neural circuitry critical for cue-guided behavior in general.
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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: 1.8] [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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7
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Abstract
Abstract
Purpose of Review
Current theories of alcohol use disorders (AUD) highlight the importance of Pavlovian and instrumental learning processes mainly based on preclinical animal studies. Here, we summarize available evidence for alterations of those processes in human participants with AUD with a focus on habitual versus goal-directed instrumental learning, Pavlovian conditioning, and Pavlovian-to-instrumental transfer (PIT) paradigms.
Recent Findings
The balance between habitual and goal-directed control in AUD participants has been studied using outcome devaluation or sequential decision-making procedures, which have found some evidence of reduced goal-directed/model-based control, but little evidence for stronger habitual responding. The employed Pavlovian learning and PIT paradigms have shown considerable differences regarding experimental procedures, e.g., alcohol-related or conventional reinforcers or stimuli.
Summary
While studies of basic learning processes in human participants with AUD support a role of Pavlovian and instrumental learning mechanisms in the development and maintenance of drug addiction, current studies are characterized by large variability regarding methodology, sample characteristics, and results, and translation from animal paradigms to human research remains challenging. Longitudinal approaches with reliable and ecologically valid paradigms of Pavlovian and instrumental processes, including alcohol-related cues and outcomes, are warranted and should be combined with state-of-the-art imaging techniques, computational approaches, and ecological momentary assessment methods.
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Vena AA, Zandy SL, Cofresí RU, Gonzales RA. Behavioral, neurobiological, and neurochemical mechanisms of ethanol self-administration: A translational review. Pharmacol Ther 2020; 212:107573. [PMID: 32437827 PMCID: PMC7580704 DOI: 10.1016/j.pharmthera.2020.107573] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/29/2020] [Indexed: 12/16/2022]
Abstract
Alcohol use disorder has multiple characteristics including excessive ethanol consumption, impaired control over drinking behaviors, craving and withdrawal symptoms, compulsive seeking behaviors, and is considered a chronic condition. Relapse is common. Determining the neurobiological targets of ethanol and the adaptations induced by chronic ethanol exposure is critical to understanding the clinical manifestation of alcohol use disorders, the mechanisms underlying the various features of the disorder, and for informing medication development. In the present review, we discuss ethanol's interactions with a variety of neurotransmitter systems, summarizing findings from preclinical and translational studies to highlight recent progress in the field. We then describe animal models of ethanol self-administration, emphasizing the value, limitations, and validity of commonly used models. Lastly, we summarize the behavioral changes induced by chronic ethanol self-administration, with an emphasis on cue-elicited behavior, the role of ethanol-related memories, and the emergence of habitual ethanol seeking behavior.
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Affiliation(s)
- Ashley A Vena
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, United States of America
| | | | - Roberto U Cofresí
- Psychological Sciences, University of Missouri, United States of America
| | - Rueben A Gonzales
- Division of Pharmacology and Toxicology, College of Pharmacy and Institute for Neuroscience, The University of Texas at Austin, United States of America.
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9
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Lamb RJ, Schindler CW, Ginsburg BC. Ethanol-paired stimuli can increase reinforced ethanol responding. Alcohol 2020; 85:27-34. [PMID: 31689483 DOI: 10.1016/j.alcohol.2019.10.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 10/24/2019] [Accepted: 10/25/2019] [Indexed: 11/29/2022]
Abstract
While ethanol-paired stimuli are frequently postulated to increase drinking motivation and thus increase ethanol responding and precipitate relapse, no study has demonstrated increases in ethanol-reinforced responding following presentation of an ethanol-paired stimulus that had not previously been part of a contingent relationship. Previous studies have shown that food-paired stimuli can increase food responding that is at low rates and increase food consumption in food-sated rats. In Experiment 1, we show that an ethanol-paired stimulus can increase ethanol responding that is at low levels late in the experimental session, presumably due to satiation. However, these increases may have resulted from either associative or non-associative mechanisms. In Experiment 2, we compared the effects of an ethanol-paired stimulus to those of the same stimulus in a Truly-Random-Control group. In a Truly-Random-Control, the stimulus and ethanol each are presented on independent random schedules, and thus any differences between the effects of the stimulus in the experimental and control groups is likely attributable to the association between the stimulus and ethanol. The stimulus increased ethanol-reinforced responding in both the experimental and control groups, but these increases were greater in the experimental than the control group. Thus, both stimulus-change and the pairing of the stimulus with ethanol may result in increases in ethanol-reinforced responding.
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Affiliation(s)
- R J Lamb
- Department of Psychiatry, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States.
| | - Charles W Schindler
- Designer Drug Unit, Intramural Research Program, National Institute on Drug Abuse, Baltimore, MD, United States
| | - Brett C Ginsburg
- Department of Psychiatry, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States
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10
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From sign-tracking to attentional bias: Implications for gambling and substance use disorders. Prog Neuropsychopharmacol Biol Psychiatry 2020; 99:109861. [PMID: 31931091 DOI: 10.1016/j.pnpbp.2020.109861] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 01/07/2020] [Accepted: 01/08/2020] [Indexed: 01/11/2023]
Abstract
Sign-tracking behavior in Pavlovian autoshaping is known to be a relevant index of the incentive salience attributed to reward-related cues. Evidence has accumulated to suggest that animals that exhibit a sign-tracker phenotype are especially vulnerable to addiction and relapse due to their proneness to attribute incentive salience to drug cues, and their relatively weak cognitive and attentional control over their behavior. Interestingly, sign-tracking is also influenced by reward uncertainty in a way that may promote gambling disorder. Research indicates that reward uncertainty sensitizes sign-tracking responses and favors the development of a sign-tracker phenotype, compatible with the conditioned attractiveness of lights and sounds in casinos for problem gamblers. The study of attentional biases in humans (an effect akin to sign-tracking in animals) leads to similar observations, notably that the propensity to develop attraction for conditioned stimuli (CSs) is predictive of addictive behavior. Here we review the literature on drug addiction and gambling disorder, highlighting the similarities between studies of sign-tracking and attentional biases.
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11
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Cofresí RU, Bartholow BD, Piasecki TM. Evidence for incentive salience sensitization as a pathway to alcohol use disorder. Neurosci Biobehav Rev 2019; 107:897-926. [PMID: 31672617 PMCID: PMC6878895 DOI: 10.1016/j.neubiorev.2019.10.009] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 10/14/2019] [Accepted: 10/15/2019] [Indexed: 12/12/2022]
Abstract
The incentive salience sensitization (ISS) theory of addiction holds that addictive behavior stems from the ability of drugs to progressively sensitize the brain circuitry that mediates attribution of incentive salience (IS) to reward-predictive cues and its behavioral manifestations. In this article, we establish the plausibility of ISS as an etiological pathway to alcohol use disorder (AUD). We provide a comprehensive and critical review of evidence for: (1) the ability of alcohol to sensitize the brain circuitry of IS attribution and expression; and (2) attribution of IS to alcohol-predictive cues and its sensitization in humans and non-human animals. We point out gaps in the literature and how these might be addressed. We also highlight how individuals with different alcohol subjective response phenotypes may differ in susceptibility to ISS as a pathway to AUD. Finally, we discuss important implications of this neuropsychological mechanism in AUD for psychological and pharmacological interventions attempting to attenuate alcohol craving and cue reactivity.
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Affiliation(s)
- Roberto U Cofresí
- University of Missouri, Department of Psychological Sciences, Columbia, MO 65211, United States.
| | - Bruce D Bartholow
- University of Missouri, Department of Psychological Sciences, Columbia, MO 65211, United States
| | - Thomas M Piasecki
- University of Missouri, Department of Psychological Sciences, Columbia, MO 65211, United States
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12
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Cofresí RU, Monfils MH, Chaudhri N, Gonzales RA, Lee HJ. Cue-alcohol associative learning in female rats. Alcohol 2019; 81:1-9. [PMID: 31002878 DOI: 10.1016/j.alcohol.2019.03.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Revised: 03/14/2019] [Accepted: 03/19/2019] [Indexed: 12/25/2022]
Abstract
The ability of environmental cues to trigger alcohol-seeking behaviors is believed to facilitate problematic alcohol use. We previously showed that the development of this cue-evoked alcohol approach reflects cue-alcohol learning and memory in the adult male rat; however, we do not know whether the same is true for similarly aged female rats. Consequently, adult Long-Evans female rats were allowed to drink unsweetened alcohol in the home cage (Monday, Wednesday, Friday; 24-h two-bottle choice; 5 weeks) and were subsequently split into two experimental groups: Paired and Unpaired. Groups were matched for ingested doses and alcohol bottle preference across the pre-conditioning home cage period. Both groups were trained in conditioning chambers using a Pavlovian procedure. For the Paired group, the chamber houselight was illuminated to signal access to an alcohol sipper. Houselight onset was yoked for the Unpaired group, but access to the alcohol sipper was scheduled to occur only during the intervening periods (in the absence of light). We found that in the Paired, but not Unpaired group, an alcohol approach reaction was conditioned to houselight illumination, and the level of cue-conditioned reactivity predicted drinking behavior within trials. Groups experienced equivalently low but non-negligible blood alcohol concentrations over the course of conditioning sessions. We conclude that cue-triggered alcohol-seeking behavior in adult female rats reflects associative learning about the relationship between alcohol availability and houselight illumination.
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13
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Lamb R, Ginsburg BC, Greig A, Schindler CW. Effects of rat strain and method of inducing ethanol drinking on Pavlovian-Instrumental-Transfer with ethanol-paired conditioned stimuli. Alcohol 2019; 79:47-57. [PMID: 30641121 DOI: 10.1016/j.alcohol.2019.01.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 01/04/2019] [Accepted: 01/07/2019] [Indexed: 12/21/2022]
Abstract
Ethanol-paired conditioned stimuli (CSs) are widely thought to invigorate ethanol responding, and thus, precipitate relapse to drinking. However, preclinical studies investigating this issue using Pavlovian-Instrumental-Transfer (PIT) procedures have had mixed results, with some studies finding PIT while others did not. The studies failing to show PIT used Lewis rats and induced ethanol drinking using a post-prandial drinking procedure. The present experiments examined whether either of these two variables influenced the magnitude of PIT observed. In the first experiment, ethanol drinking in Lewis rats was induced using either sucrose fading or post-prandial drinking. In the second experiment, ethanol drinking was induced using post-prandial drinking in either Long-Evans Hooded or Lewis rats. In both experiments, rats were trained to respond for ethanol under a random interval schedule. Subsequently with the lever removed, 2-min light presentations were paired with ethanol deliveries. Finally, with the lever returned, the effect of light presentations on responding was tested while responding was in extinction. Light presentations similarly affected responding in Lewis rats regardless of the method of drinking induction. Likewise, light presentations similarly affected responding in both Lewis and Long-Evans Hooded rats. Neither ethanol induction method nor rat strain affected the magnitude of PIT observed, and thus, neither likely explains previous failures to observe PIT with ethanol-maintained behavior.
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14
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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: 2.3] [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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15
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Hellberg SN, Russell TI, Robinson MJF. Cued for risk: Evidence for an incentive sensitization framework to explain the interplay between stress and anxiety, substance abuse, and reward uncertainty in disordered gambling behavior. COGNITIVE, AFFECTIVE & BEHAVIORAL NEUROSCIENCE 2019; 19:737-758. [PMID: 30357661 PMCID: PMC6482104 DOI: 10.3758/s13415-018-00662-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Gambling disorder is an impairing condition confounded by psychiatric co-morbidity, particularly with substance use and anxiety disorders. Yet, our knowledge of the mechanisms that cause these disorders to coalesce remains limited. The Incentive Sensitization Theory suggests that sensitization of neural "wanting" pathways, which attribute incentive salience to rewards and their cues, is responsible for the excessive desire for drugs and cue-triggered craving. The resulting hyper-reactivity of the "wanting' system is believed to heavily influence compulsive drug use and relapse. Notably, evidence for sensitization of the mesolimbic dopamine pathway has been seen across gambling and substance use, as well as anxiety and stress-related pathology, with stress playing a major role in relapse. Together, this evidence highlights a phenomenon known as cross-sensitization, whereby sensitization to stress, drugs, or gambling behaviors enhance the sensitivity and dopaminergic response to any of those stimuli. Here, we review the literature on how cue attraction and reward uncertainty may underlie gambling pathology, and examine how this framework may advance our understanding of co-mordidity with substance-use disorders (e.g., alcohol, nicotine) and anxiety disorders. We argue that reward uncertainty, as seen in slot machines and games of chance, increases dopaminergic activity in the mesolimbic pathway and enhances the incentive value of reward cues. We propose that incentive sensitization by reward uncertainty may interact with and predispose individuals to drug abuse and stress, creating a mechanism through which co-mordidity of these disorders may emerge.
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Affiliation(s)
- Samantha N Hellberg
- Psychology Department and the Neuroscience and Behavior Program, Wesleyan University, 207 High Street, Middletown, CT, 06457, USA
- University of North Carolina Chapel Hill, Chapel Hill, NC, USA
| | - Trinity I Russell
- Psychology Department and the Neuroscience and Behavior Program, Wesleyan University, 207 High Street, Middletown, CT, 06457, USA
- National Institutes on Drug Abuse, Baltimore, MD, USA
| | - Mike J F Robinson
- Psychology Department and the Neuroscience and Behavior Program, Wesleyan University, 207 High Street, Middletown, CT, 06457, USA.
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Alcohol-associated antecedent stimuli elicit alcohol seeking in non-dependent rats and may activate the insula. Alcohol 2019; 76:91-102. [PMID: 30612041 DOI: 10.1016/j.alcohol.2018.08.004] [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: 01/04/2018] [Revised: 07/22/2018] [Accepted: 08/10/2018] [Indexed: 02/07/2023]
Abstract
Alcohol self-administration produces brain and behavior adaptations that facilitate a progressive loss of control over drinking and contribute to relapse. One possible adaptation is the ability of antecedent environmental stimuli that are consistently paired with alcohol to trigger alcohol-seeking behaviors. We previously modeled this adaptation in rats using a Pavlovian conditioning procedure in which illumination of a houselight preceded the presentation of a sipper tube that produced unsweetened alcohol when licked. However, in our previous work we did not demonstrate whether this adaptation represented a consequence of repeated exposure to alcohol or the houselight, or whether it was the consequence of associative learning and memory. Thus, in the present study, we tested the associative basis of alcohol seeking in response to houselight illumination in our task using adult male rats that were not food- or water-deprived and were not dependent on alcohol. Separate groups of rats received houselight illumination that was explicitly paired or unpaired with presentation of the retractable sipper that provided access to unsweetened alcohol. Our primary dependent variable was appetitive alcohol-directed behavior: the frequency of movement toward and interaction with the hole in the wall of the chamber through which the sipper was presented during the period of houselight illumination trial before each sipper presentation. However, we also analyzed consummatory sipper licking behavior and blood ethanol concentration in the same rats. Finally, we explored the brain basis of cue-elicited alcohol seeking using c-Fos immunohistochemistry. Our findings confirmed the associative basis of cue-elicited alcohol seeking in our paradigm and mapped these onto the insular cortex, suggesting a role for this brain region in early stages of brain and behavior adaptation to regular alcohol use.
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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: 0.8] [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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Millan EZ, Kim HA, Janak PH. Optogenetic activation of amygdala projections to nucleus accumbens can arrest conditioned and unconditioned alcohol consummatory behavior. Neuroscience 2017; 360:106-117. [PMID: 28757250 PMCID: PMC5752133 DOI: 10.1016/j.neuroscience.2017.07.044] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 07/13/2017] [Accepted: 07/19/2017] [Indexed: 11/25/2022]
Abstract
Following a Pavlovian pairing procedure, alcohol-paired cues come to elicit behavioral responses that lead to alcohol consumption. Here we used an optogenetic approach to activate basolateral amygdala (BLA) axonal terminals targeting the shell of nucleus accumbens (AcbSh) and investigated a possible influence over cue-conditioned alcohol seeking and alcohol drinking, based on the demonstrated roles of these areas in behavioral responding to Pavlovian cues and in feeding behavior. Rats were trained to anticipate alcohol or sucrose following the onset of a discrete conditioned stimulus (CS). Channelrhodopsin-mediated activation of the BLA-to-AcbSh pathway concurrent with each CS disrupted cued alcohol seeking. Activation of the same pathway caused rapid cessation of alcohol drinking from a sipper tube. Neither effect was accompanied by an overall change in locomotion. Finally, the suppressive effect of photoactivation on cued-triggered seeking was also evidenced in animals trained with sucrose. Together these findings suggest that photoactivation of BLA terminals in the AcbSh can override the conditioned motivational properties of reward-predictive cues as well as unconditioned consummatory responses necessary for alcohol drinking. The findings provide evidence for a limbic-striatal influence over motivated behavior for orally consumed rewards, including alcohol.
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Affiliation(s)
- E Zayra Millan
- Department of Psychological and Brain Sciences, Krieger School of Arts and Sciences, Johns Hopkins University, Baltimore MD 21218, United States.
| | - H Amy Kim
- Department of Psychological and Brain Sciences, Krieger School of Arts and Sciences, Johns Hopkins University, Baltimore MD 21218, United States
| | - Patricia H Janak
- Department of Psychological and Brain Sciences, Krieger School of Arts and Sciences, Johns Hopkins University, Baltimore MD 21218, United States; Solomon H. Snyder Department of Neuroscience, Johns Hopkins School of Medicine, Johns Hopkins University, Baltimore MD 21205, United States.
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19
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Krank M, Robinson J. Automatic Cognitive Processes and Youth Substance Use: Risks and Prevention. CURRENT ADDICTION REPORTS 2017. [DOI: 10.1007/s40429-017-0168-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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20
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Alcohol-seeking and relapse: A focus on incentive salience and contextual conditioning. Behav Processes 2017; 141:26-32. [DOI: 10.1016/j.beproc.2017.04.019] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Revised: 04/27/2017] [Accepted: 04/28/2017] [Indexed: 01/05/2023]
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Lamb RJ, Ginsburg BC, Schindler CW. Conditioned Stimulus Form Does Not Explain Failures to See Pavlovian-Instrumental-Transfer With Ethanol-Paired Conditioned Stimuli. Alcohol Clin Exp Res 2017; 41:1063-1071. [PMID: 28294355 DOI: 10.1111/acer.13376] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Accepted: 03/08/2017] [Indexed: 01/15/2023]
Abstract
BACKGROUND Pavlovian-Instrumental-Transfer (PIT) examines the effects of associative learning upon instrumental responding. Previous studies examining PIT with ethanol (EtOH)-maintained responding showed increases in responding following presentation of an EtOH-paired conditioned stimulus (CS). Recently, we conducted 2 studies examining PIT with an EtOH-paired CS. One of these found increases in responding, while the other did not. This less robust demonstration of PIT may have resulted from the form of the CS used, as we used a 120-second light stimulus as a CS, while the previous studies used either a 120-second auditory stimulus or a 10-second light stimulus. This study examined whether using conditions similar to our earlier study, but with either a 120-second auditory or a 10-second light stimulus as a CS, resulted in more robust PIT. We also examined the reliability of our previous failure to observe PIT. METHODS Three experiments were conducted examining whether PIT was obtained using (i) a 120-second light stimulus, (ii) a 10-second light stimulus, or (iii) a 120-second auditory stimulus as CSs. RESULTS We found PIT was not obtained using (i) a 120-second light stimulus as a CS, (ii) a 10-second light stimulus as a CS, or (iii) a 120-second auditory stimulus as a CS. CONCLUSIONS These results suggest that CS form does not account for our earlier failure to see PIT. Rather, factors like rat strain or how EtOH drinking is induced may account for when PIT is or is not observed.
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Affiliation(s)
- Richard J Lamb
- Department of Psychiatry, University of Texas Health Science Center at San Antonio, San Antonio, Texas.,Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, Texas
| | - Brett C Ginsburg
- Department of Psychiatry, University of Texas Health Science Center at San Antonio, San Antonio, Texas.,Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, Texas
| | - Charles W Schindler
- Designer Drug Unit, Intramural Research Program, National Institute on Drug Abuse, Baltimore, Maryland
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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: 1.1] [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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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: 2.7] [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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Lamb R, Ginsburg BC, Schindler CW. Effects of an ethanol-paired CS on responding for ethanol and food: Comparisons with a stimulus in a Truly-Random-Control group and to a food-paired CS on responding for food. Alcohol 2016; 57:15-27. [PMID: 27916139 DOI: 10.1016/j.alcohol.2016.10.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Revised: 09/13/2016] [Accepted: 10/18/2016] [Indexed: 12/17/2022]
Abstract
Motivational increases due to exposure to alcohol-paired Conditioned Stimuli (CS) are central to some accounts of alcoholism. However, few studies isolate a stimulus's function as a CS from its other potential functions. Pavlovian-Instrumental-Transfer (PIT) procedures isolate a stimulus's function as a CS from its other functions. Though there are several relevant studies using PIT, knowledge gaps exist. Particularly, it is not clear that an alcohol-paired CS will increase alcohol seeking compared to the same stimulus in a Truly-Random-Control group, nor whether such increases are specific to alcohol seeking. To address these knowledge gaps in Experiment 1, rats responded for ethanol (0.1 ml 8% w/v) under an RI 30-sec schedule, then the lever was removed and half the rats had ethanol delivered during occasional 120-sec light presentations, while the remainder had ethanol and the light presented under independent RT schedules. Later the lever was returned and the light was presented during responding in extinction (PIT test). Following this test, levers were again removed and the light was presented without ethanol (light extinction), following again by a PIT test. Responding in the two groups during light presentations did not differ in either PIT test. Experiment 2 repeated Experiment 1 using food instead of ethanol. In Experiment 2, responding during light presentations increased in the paired group. In Experiment 3, rats were trained on a concurrent FR schedule of food and ethanol delivery. Ethanol was delivered following 5 responses and the response requirement for food adjusted so that similar numbers of food and ethanol deliveries were obtained. Subsequently, rats underwent conditioning, control and testing procedures identical to those in Experiment 1. In Experiment 3, the ethanol-paired CS increased ethanol-responding, but not food-responding. These results are most easily interpreted as changes in responding resulting from CS-elicited behavior rather than motivational changes. This interpretation is more compatible with some descriptions of the role of an alcohol-paired CS in alcoholism than others.
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Cartoni E, Balleine B, Baldassarre G. Appetitive Pavlovian-instrumental Transfer: A review. Neurosci Biobehav Rev 2016; 71:829-848. [DOI: 10.1016/j.neubiorev.2016.09.020] [Citation(s) in RCA: 167] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2016] [Revised: 09/23/2016] [Accepted: 09/23/2016] [Indexed: 11/26/2022]
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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: 43] [Impact Index Per Article: 4.8] [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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Lamb RJ, Schindler CW, Pinkston JW. Conditioned stimuli's role in relapse: preclinical research on Pavlovian-Instrumental-Transfer. Psychopharmacology (Berl) 2016; 233:1933-44. [PMID: 26800688 PMCID: PMC4863941 DOI: 10.1007/s00213-016-4216-y] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 01/12/2016] [Indexed: 01/24/2023]
Abstract
RATIONALE AND OBJECTIVE Pavlovian learning is central to many theories of addiction. In these theories, stimuli paired with drug ingestion become conditioned stimuli (CS) and subsequently elicit drug-seeking and drug-taking. However, in most relevant studies, Pavlovian and instrumental learning are confounded. This confound may be avoided in Pavlovian-Instrumental-Transfer (PIT) procedures. In PIT, Pavlovian and instrumental learning are established separately and then combined. In order to better understand the role of CSs in addiction, we review the relevant studies using PIT. FINDINGS We identified seven articles examining PIT effects of ethanol- or cocaine-paired CSs. Under at least one condition, six of these articles reported CS-elicited increases in responding previously maintained by drug. However, the only study using the optimal control condition failed to find a CS-elicited increase. Two studies examining CS specificity found the CS also increased responding maintained by a different reinforcer. Two studies examined if CSs elicit increases in actual drug-taking. Both failed to find CS-elicited increases, i.e., no study shows CS-elicited increases in actual drug-taking. Further, CS-elicited increases in extinguished responding are short-lived. CONCLUSIONS These findings are not entirely consistent with Pavlovian learning playing a central role in addiction. However, design issues can explain most of these inconsistencies. Studies without these design issues are needed. Additionally, existing theories hypothesize drug-paired CSs increase drug-taking by increasing motivation, by eliciting conditioned responses that make drug-seeking more probable, or by a combination of these. Work distinguishing between these mechanisms would also be useful.
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Affiliation(s)
- R J Lamb
- Departments of Psychiatry & Pharmacology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX, 78229-3900, USA.
| | - Charles W Schindler
- Preclinical Pharmacology Section, Behavioral Neuroscience Research Branch, Intramural Research Program, National Institute on Drug Abuse, 251 Bayview Blvd, Baltimore, MD, 21224, USA
| | - Jonathan W Pinkston
- Department of Behavioral Analysis, University of North Texas, 360 G Chilton Hall, Avenue C, Denton, TX, 76208, USA
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Richard JM, Fields HL. Mu-opioid receptor activation in the medial shell of nucleus accumbens promotes alcohol consumption, self-administration and cue-induced reinstatement. Neuropharmacology 2016; 108:14-23. [PMID: 27089981 DOI: 10.1016/j.neuropharm.2016.04.010] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2015] [Revised: 04/06/2016] [Accepted: 04/08/2016] [Indexed: 01/06/2023]
Abstract
Endogenous opioid signaling in ventral cortico-striatal-pallidal circuitry is implicated in elevated alcohol consumption and relapse to alcohol seeking. Mu-opioid receptor activation in the medial shell of the nucleus accumbens (NAc), a region implicated in multiple aspects of reward processing, elevates alcohol consumption while NAc opioid antagonists reduce it. However, the precise nature of the increases in alcohol consumption, and the effects of mu-opioid agonists on alcohol seeking and relapse are not clear. Here, we tested the effects of the mu-opioid agonist [D-Ala(2), N-MePhe(4), Gly-ol]-enkephalin (DAMGO) in rat NAc shell on lick microstructure in a free-drinking test, alcohol seeking during operant self-administration, extinction learning and expression, and cue-reinforced reinstatement of alcohol seeking. DAMGO enhanced the number, but not the size of drinking bouts. DAMGO also enhanced operant alcohol self-administration and cue-induced reinstatement, but did not affect extinction learning or elicit reinstatement in the absence of cues. Our results suggest that mu-opioid agonism in NAc shell elevates alcohol consumption, seeking and conditioned reinforcement primarily by enhancing the incentive motivational properties of alcohol and alcohol-paired cues, rather than by modulating palatability, satiety, or reinforcement.
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Affiliation(s)
- Jocelyn M Richard
- Department of Neurology, The Wheeler Center for the Neurobiology of Addiction, Alcoholism and Addiction Research Group, University of California, San Francisco, CA, USA.
| | - Howard L Fields
- Department of Neurology, The Wheeler Center for the Neurobiology of Addiction, Alcoholism and Addiction Research Group, University of California, San Francisco, CA, USA.
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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: 2.3] [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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Srey CS, Maddux JMN, Chaudhri N. The attribution of incentive salience to Pavlovian alcohol cues: a shift from goal-tracking to sign-tracking. Front Behav Neurosci 2015; 9:54. [PMID: 25784867 PMCID: PMC4347508 DOI: 10.3389/fnbeh.2015.00054] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Accepted: 02/13/2015] [Indexed: 11/22/2022] Open
Abstract
Environmental stimuli that are reliably paired with alcohol may acquire incentive salience, a property that can operate in the use and abuse of alcohol. Here we investigated the incentive salience of Pavlovian alcohol cues using a preclinical animal model. Male, Long-Evans rats (Harlan) with unrestricted access to food and water were acclimated to drinking 15% ethanol (v/v) in their home-cages. Rats then received Pavlovian autoshaping training in which the 10 s presentation of a retractable lever served as the conditioned stimulus (CS) and 15% ethanol served as the unconditioned stimulus (US) (0.2 ml/CS; 12 CS presentations/session; 27 sessions). Next, in an operant test of conditioned reinforcement, nose pokes into an active aperture delivered presentations of the lever-CS, whereas nose pokes into an inactive aperture had no consequences. Across initial autoshaping sessions, goal-tracking behavior, as measured by entries into the fluid port where ethanol was delivered, developed rapidly. However, with extended training goal-tracking diminished, and sign-tracking responses, as measured by lever-CS activations, emerged. Control rats that received explicitly unpaired CS and US presentations did not show goal-tracking or sign-tracking responses. In the test for conditioned reinforcement, rats with CS-US pairings during autoshaping training made more active relative to inactive nose pokes, whereas rats in the unpaired control group did not. Moreover, active nose pokes were positively correlated with sign-tracking behavior during autoshaping. Extended training may produce a shift in the learned properties of Pavlovian alcohol cues, such that after initially predicting alcohol availability they acquire robust incentive salience.
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Affiliation(s)
- Chandra S Srey
- Department of Psychology, Center for Studies in Behavioral Neurobiology/FRQS Groupe de Recherche en Neurobiologie Comportementale, Concordia University Montreal, QC, Canada
| | - Jean-Marie N Maddux
- Department of Psychology, Center for Studies in Behavioral Neurobiology/FRQS Groupe de Recherche en Neurobiologie Comportementale, Concordia University Montreal, QC, Canada
| | - Nadia Chaudhri
- Department of Psychology, Center for Studies in Behavioral Neurobiology/FRQS Groupe de Recherche en Neurobiologie Comportementale, Concordia University Montreal, QC, Canada
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Peters J, De Vries TJ. Pavlovian conditioned approach, extinction, and spontaneous recovery to an audiovisual cue paired with an intravenous heroin infusion. Psychopharmacology (Berl) 2014; 231:447-53. [PMID: 24026484 DOI: 10.1007/s00213-013-3258-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2013] [Accepted: 08/13/2013] [Indexed: 10/26/2022]
Abstract
RATIONALE Novel stimuli paired with exposure to addictive drugs can elicit approach through Pavlovian learning. While such approach behavior, or sign tracking, has been documented for cocaine and alcohol, it has not been shown to occur with opiate drugs like heroin. Most Pavlovian conditioned approach paradigms use an operandum as the sign, so that sign tracking can be easily automated. OBJECTIVES We were interested in assessing whether approach behavior occurs to an audiovisual cue paired with an intravenous heroin infusion. If so, would this behavior exhibit characteristics of other Pavlovian conditioned behaviors, such as extinction and spontaneous recovery? METHODS Rats were repeatedly exposed to an audiovisual cue, similar to that used in standard self-administration models, along with an intravenous heroin infusion. Sign tracking was measured in an automated fashion by analyzing motion pixels within the cue zone during each cue presentation. RESULTS We were able to observe significant sign tracking after only five pairings of the conditioned stimulus (CS) with the unconditioned stimulus (US). This behavior rapidly extinguished over 2 days, but exhibited pronounced spontaneous recovery 3 weeks later. CONCLUSIONS We conclude that sign tracking measured by these methods exhibits all the characteristics of a classically conditioned behavior. This model can be used to examine the Pavlovian component of drug memories, alone, or in combination with self-administration methods.
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Affiliation(s)
- Jamie Peters
- Department of Anatomy and Neurosciences, Neuroscience Campus Amsterdam, VU University medical center, 1081BT, Amsterdam, The Netherlands,
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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: 9.5] [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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Robinson TE, Yager LM, Cogan ES, Saunders BT. On the motivational properties of reward cues: Individual differences. Neuropharmacology 2013; 76 Pt B:450-9. [PMID: 23748094 DOI: 10.1016/j.neuropharm.2013.05.040] [Citation(s) in RCA: 175] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2013] [Revised: 05/14/2013] [Accepted: 05/17/2013] [Indexed: 10/26/2022]
Abstract
Cues associated with rewards, such as food or drugs of abuse, can themselves acquire motivational properties. Acting as incentive stimuli, such cues can exert powerful control over motivated behavior, and in the case of cues associated with drugs, they can goad continued drug-seeking behavior and relapse. However, recent studies reviewed here suggest that there are large individual differences in the extent to which food and drug cues are attributed with incentive salience. Rats prone to approach reward cues (sign-trackers) attribute greater motivational value to discrete localizable cues and interoceptive cues than do rats less prone to approach reward cues (goal-trackers). In contrast, contextual cues appear to exert greater control over motivated behavior in goal-trackers than sign-trackers. It is possible to predict, therefore, before any experience with drugs, in which animals specific classes of drug cues will most likely reinstate drug-seeking behavior. The finding that different individuals may be sensitive to different triggers capable of motivating behavior and producing relapse suggests there may be different pathways to addiction, and has implications for thinking about individualized treatment. This article is part of a Special Issue entitled 'NIDA 40th Anniversary Issue'.
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Affiliation(s)
- Terry E Robinson
- Department of Psychology (Biopsychology Program), University of Michigan, 530 Church Street, East Hall, Ann Arbor, MI 48109, USA.
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Milton AL, Schramm MJW, Wawrzynski JR, Gore F, Oikonomou-Mpegeti F, Wang NQ, Samuel D, Economidou D, Everitt BJ. Antagonism at NMDA receptors, but not β-adrenergic receptors, disrupts the reconsolidation of pavlovian conditioned approach and instrumental transfer for ethanol-associated conditioned stimuli. Psychopharmacology (Berl) 2012; 219:751-61. [PMID: 21766171 DOI: 10.1007/s00213-011-2399-9] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2011] [Accepted: 06/23/2011] [Indexed: 10/18/2022]
Abstract
RATIONALE Reconsolidation is the process by which memories require restabilisation following destabilisation at retrieval. Since even old, well-established memories become susceptible to disruption following reactivation, treatments based upon disrupting reconsolidation could provide a novel form of therapy for neuropsychiatric disorders based upon maladaptive memories, such as drug addiction. Pavlovian cues are potent precipitators of relapse to drug-seeking behaviour and influence instrumental drug seeking through at least three psychologically and neurobiologically distinct processes: conditioned reinforcement, conditioned approach (autoshaping) and conditioned motivation (pavlovian-instrumental transfer or PIT). We have previously demonstrated that the reconsolidation of memories underlying the conditioned reinforcing properties of drug cues depends upon NMDA receptor (NMDAR)- and β-adrenergic receptor (βAR)-mediated signalling. However, it is unknown whether the drug cue memory representations underlying conditioned approach and PIT depend upon the same mechanisms. OBJECTIVES Using orally self-administered ethanol as a reinforcer in two separate experiments, we investigated whether the reconsolidation of the memories underlying conditioned approach and PIT requires βAR- and NMDAR-dependent neurotransmission. RESULTS For ethanol self-administering but non-dependent rats, the memories underlying conditioned approach and PIT for a pavlovian drug cue were disrupted by the administration of the NMDAR antagonist MK-801, but not the administration of the βAR antagonist propranolol, when given in conjunction with memory reactivation. CONCLUSIONS As for natural reinforcers, NMDARs are required for the reconsolidation of all aspects of pavlovian drug memories, but βARs are only required for the memory representation underlying conditioned reinforcement. These results indicate the potential utility of treatments based upon disrupting cue-drug memory reconsolidation in preventing relapse.
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Affiliation(s)
- Amy L Milton
- Behavioural and Clinical Neuroscience Institute, Department of Experimental Psychology, University of Cambridge, Downing Site, Cambridge, CB2 3EB, UK.
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Brennan CH, Parker MO. Zebrafish (Danio rerio) models of substance abuse: Harnessing the capabilities. BEHAVIOUR 2012. [DOI: 10.1163/1568539x-00003010] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Christiansen P, Cole JC, Goudie AJ, Field M. Components of behavioural impulsivity and automatic cue approach predict unique variance in hazardous drinking. Psychopharmacology (Berl) 2012; 219:501-10. [PMID: 21735071 DOI: 10.1007/s00213-011-2396-z] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2011] [Accepted: 06/22/2011] [Indexed: 10/18/2022]
Abstract
RATIONALE Hazardous drinking is associated with both increased impulsivity and automatic approach tendencies elicited by alcohol-related cues. However, impulsivity is a multi-factorial construct, and it is currently unclear if all components of impulsivity are associated with heavy drinking. Furthermore, emerging evidence suggests that the relationships between hazardous drinking and automatic alcohol cognitions may be moderated by individual differences in impulsivity. OBJECTIVES The aim of this study was to investigate the independence of measures of impulsivity and their association with hazardous drinking, and to examine if the relationship between hazardous drinking and automatic alcohol approach tendencies would be moderated by individual differences in impulsivity. METHODS Ninety-seven social drinkers (65 female) completed questionnaire measures of trait impulsivity, alcohol consumption and hazardous drinking. Participants also completed computerised measures of automatic alcohol approach tendencies (stimulus-response compatibility (SRC) task), and two behavioural measures of impulsivity (Go/No-go and delay discounting tasks). RESULTS Principal component analysis revealed that the two measures of behavioural impulsivity were distinct from each other and from self-reported trait impulsivity, although self-reported non-planning impulsivity loaded on to two factors (trait impulsivity and delay discounting). Furthermore, all measures of impulsivity predicted unique variance in hazardous drinking as did automatic alcohol approach tendencies, although the latter relationship was not moderated by impulsivity. CONCLUSIONS These results indicate that multiple components of impulsivity and automatic alcohol approach tendencies explain unique variance in hazardous drinking.
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Affiliation(s)
- Paul Christiansen
- School of Psychology, University of Liverpool, Liverpool, L69 7ZA, UK.
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37
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Milton AL, Everitt BJ. The psychological and neurochemical mechanisms of drug memory reconsolidation: implications for the treatment of addiction. Eur J Neurosci 2010; 31:2308-19. [PMID: 20497475 DOI: 10.1111/j.1460-9568.2010.07249.x] [Citation(s) in RCA: 178] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Memory reconsolidation is the process by which memories, destabilised at retrieval, require restabilisation to persist in the brain. It has been demonstrated that even old, well-established memories require reconsolidation following retrieval; therefore, memory reconsolidation could potentially be exploited to disrupt, or even erase, aberrant memories that underlie psychiatric disorders, thereby providing a novel therapeutic target. Drug addiction is one such disorder; it is both chronic and relapsing, and one prominent risk factor for a relapse episode is the presentation of environmental cues that have previously been associated with drugs of abuse. This 'cue-induced relapse' can be accounted for in psychological terms by reinforcing memories of the pavlovian association between the cue and the drug, which can thus influence behaviour through at least three psychologically and neurobiologically dissociable mechanisms: conditioned reinforcement, conditioned approach and conditioned motivation. As each of these psychological processes could contribute to the resumption of drug-seeking following abstinence, it is important to develop treatments that can reduce drug-seeking re-established via influences on each or all of these pavlovian processes, in order to minimise the risk of a subsequent relapse. Investigation of the memory reconsolidation mechanisms of the memories underlying conditioned reinforcement, conditioned approach and conditioned motivation indicate that they depend upon different neurochemical systems, including the glutamatergic and adrenergic systems within limbic corticostriatal circuitry. We also discuss here the subsequent translation to the clinic of this preclinical work.
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Affiliation(s)
- Amy L Milton
- Department of Experimental Psychology, Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK.
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Twining RC, Bolan M, Grigson PS. Yoked delivery of cocaine is aversive and protects against the motivation for drug in rats. Behav Neurosci 2009; 123:913-25. [PMID: 19634952 DOI: 10.1037/a0016498] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
In Experiment 1, water-deprived rats had 5-min access to saccharin followed by active or yoked intravenous delivery of saline or cocaine (0.33 mg/infusion). Both cocaine groups avoided intake of the saccharin cue following saccharin-cocaine pairings; however, the rats in the yoked condition exhibited greater avoidance of the taste cue than did the actively administering rats. Experiment 2 evaluated subsequent self-administration behavior on fixed- and progressive-ratio schedules of reinforcement. The results showed that prior yoked exposure to cocaine reduced subsequent drug-taking behavior on a progressive-ratio but not on a fixed-ratio schedule. Finally, Experiment 3 used a choice test to determine the impact of yoked drug delivery on the relative preference for cocaine versus water. The results showed that rats with a history of self-administering cocaine preferred to perform operant behaviors on the side of the chamber previously paired with cocaine, whereas the rats with a history of yoked delivery of cocaine avoided this side. These data show that, in most rats, the unpredictable, uncontrollable delivery of cocaine protects against the subsequent motivation for cocaine through an aversive mechanism.
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Affiliation(s)
- Robert C Twining
- Department of Neural and Behavioral Sciences, Pennsylvania State College of Medicine, Hershey, USA.
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Flagel SB, Akil H, Robinson TE. Individual differences in the attribution of incentive salience to reward-related cues: Implications for addiction. Neuropharmacology 2008; 56 Suppl 1:139-48. [PMID: 18619474 PMCID: PMC2635343 DOI: 10.1016/j.neuropharm.2008.06.027] [Citation(s) in RCA: 373] [Impact Index Per Article: 21.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2008] [Revised: 06/10/2008] [Accepted: 06/14/2008] [Indexed: 11/27/2022]
Abstract
Drugs of abuse acquire different degrees of control over thoughts and actions based not only on the effects of drugs themselves, but also on predispositions of the individual. Those individuals who become addicted are unable to shift their thoughts and actions away from drugs and drug-associated stimuli. Thus in addicts, exposure to places or things (cues) that has been previously associated with drug-taking often instigates renewed drug-taking. We and others have postulated that drug-associated cues acquire the ability to maintain and instigate drug-taking behavior in part because they acquire incentive motivational properties through Pavlovian (stimulus-stimulus) learning. In the case of compulsive behavioral disorders, including addiction, such cues may be attributed with pathological incentive value ("incentive salience"). For this reason, we have recently begun to explore individual differences in the tendency to attribute incentive salience to cues that predict rewards. When discrete cues are associated with the non-contingent delivery of food or drug rewards some animals come to quickly approach and engage the cue even if it is located at a distance from where the reward will be delivered. In these animals the reward-predictive cue itself becomes attractive, eliciting approach towards it, presumably because it is attributed with incentive salience. Animals that develop this type of conditional response are called "sign-trackers". Other animals, "goal-trackers", do not approach the reward-predictive cue, but upon cue presentation they immediately go to the location where food will be delivered (the "goal"). For goal-trackers the reward-predictive cue is not attractive, presumably because it is not attributed with incentive salience. We review here preliminary data suggesting that these individual differences in the tendency to attribute incentive salience to cues predictive of reward may confer vulnerability or resistance to compulsive behavioral disorders, including addiction. It will be important, therefore, to study how environmental, neurobiological and genetic interactions determine the extent to which individuals attribute incentive value to reward-predictive stimuli.
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Affiliation(s)
- Shelly B Flagel
- Molecular and Behavioral Neuroscience Institute, University of Michigan, Ann Arbor, MI 48109, USA.
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