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Namba MD, Xie Q, Park K, Jackson JG, Barker JM. EcoHIV Infection Modulates the Effects of Cocaine Exposure Pattern and Abstinence on Cocaine Seeking and Neuroimmune Protein Expression in Male Mice. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.15.589615. [PMID: 38659915 PMCID: PMC11042347 DOI: 10.1101/2024.04.15.589615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
Cocaine use disorders (CUDs) and human immunodeficiency virus (HIV) remain persistent public health dilemmas throughout the world. One major hurdle for treating CUD is the increase in cocaine craving and seeking behavior that occurs over a protracted period of abstinence, an effect known as the incubation of craving. Little is known about how HIV may modulate this process. Thus, we sought to examine the impact of chronic HIV infection on the incubation of cocaine craving and associated changes in the central and peripheral immune systems. Here, mice were inoculated with EcoHIV, which is a chimeric HIV-1 construct that produces chronic HIV infection in mice. EcoHIV- and sham-infected mice were conditioned with cocaine daily or intermittently in a conditioned place preference (CPP) paradigm, followed by 1 or 21 days of forced abstinence prior to assessing preference for the cocaine-paired chamber. Under both conditioning regimens, sham mice exhibited incubation of cocaine CPP after 21 days of abstinence. EcoHIV-infected mice conditioned daily with cocaine showed enhanced cocaine seeking at both abstinence timepoints, whereas infected mice conditioned intermittently showed a reversal of the incubation effect, with higher cocaine seeking after 1 day of abstinence compared to 21 days. Analysis of corticolimbic CX3CL1-CX3CR1 and glutamate receptor expression revealed alterations in medial prefrontal cortex (mPFC) CX3CL1 and nucleus accumbens (NAc) GluN2A receptors that correlated with cocaine seeking following daily cocaine exposure. Moreover, examination of peripheral immune markers showed that the effect of abstinence and EcoHIV infection on these measures depended on the cocaine exposure regimen. Altogether, these results highlight the importance of cocaine abstinence and exposure pattern as critical variables that modulate HIV-associated neuroimmune outcomes and relapse vulnerability.
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Affiliation(s)
- Mark D. Namba
- Department of Pharmacology & Physiology, College of Medicine, Drexel University, Philadelphia, PA, USA
| | - Qiaowei Xie
- Department of Pharmacology & Physiology, College of Medicine, Drexel University, Philadelphia, PA, USA
- Graduate Program in Pharmacology and Physiology, College of Medicine, Drexel University
| | - Kyewon Park
- Center for AIDS Research (CFAR), University of Pennsylvania, Philadelphia, PA, USA
| | - Joshua G. Jackson
- Department of Pharmacology & Physiology, College of Medicine, Drexel University, Philadelphia, PA, USA
| | - Jacqueline M. Barker
- Department of Pharmacology & Physiology, College of Medicine, Drexel University, Philadelphia, PA, USA
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Doyle MR, Beltran NM, Bushnell MSA, Syed M, Acosta V, Desai M, Rice KC, Serafine KM, Gould GG, Daws LC, Collins GT. Effects of access condition on substance use disorder-like phenotypes in male and female rats self-administering MDPV or cocaine. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.04.583431. [PMID: 38496609 PMCID: PMC10942381 DOI: 10.1101/2024.03.04.583431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/19/2024]
Abstract
Substance use disorder (SUD) is a heterogeneous disorder, where severity, symptoms, and patterns of substance use vary across individuals. Yet, when rats are allowed to self-administer drugs such as cocaine under short-access conditions, their behavior tends to be well-regulated and homogeneous in nature; though individual differences can emerge when rats are provided long- or intermittent-access to cocaine. In contrast to cocaine, significant individual differences emerge when rats are allowed to self-administer 3,4-methylenedioxypyrovalerone (MDPV), even under short-access conditions, wherein ~30% of rats rapidly transition to high levels of drug-taking. This study assessed the SUD-like phenotypes of male and female Sprague Dawley rats self-administering MDPV (0.032 mg/kg/infusion) or cocaine (0.32 mg/kg/infusion) by comparing level of drug intake, responding during periods of signaled drug unavailability, and sensitivity to footshock punishment to test the hypotheses that: (1) under short-access conditions, rats that self-administer MDPV will exhibit a more robust SUD-like phenotype than rats that self-administered cocaine; (2) female rats will have a more severe phenotype than male rats; and (3) compared to short-access, long- and intermittent-access to MDPV or cocaine self-administration will result in a more robust SUD-like phenotype. After short-access, rats that self-administered MDPV exhibited a more severe phenotype than rats that self-administered cocaine. Though long- and intermittent-access to cocaine and MDPV self-administration altered drug-taking patterns, manipulating access conditions did not systematically alter their SUD-like phenotype. Evidence from behavioral and quantitative autoradiography studies suggest that these differences are unlikely due to changes in expression levels of dopamine transporter, dopamine D2 or D3 receptors, or 5-HT1B, 5-HT2A, or 5-HT2C receptors, though these possibilities cannot be ruled out. These results show that the phenotype exhibited by rats self-administering MDPV differs from that observed for rats self-administering cocaine, and suggests that individuals that use MDPV and/or related cathinones may be at greater risk for developing a SUD, and that short-access MDPV self-administration may provide a useful method to understand the factors that mediate the transition to problematic or disordered substance use in humans.
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Affiliation(s)
- Michelle R. Doyle
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Nina M. Beltran
- Department of Psychology, University of Texas at El Paso, El Paso, TX, USA
| | - Mark S. A. Bushnell
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Maaz Syed
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Valeria Acosta
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Marisa Desai
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Kenner C. Rice
- Drug Design and Synthesis Section, Molecular Targets and Medications Discovery Branch National Institute on Drug Abuse and National Institute on Alcohol Abuse and Alcoholism - Intramural Research Program, Bethesda, MD
| | | | - Georgianna G. Gould
- Department of Cellular and Integrative Physiology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Lynette C. Daws
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
- Department of Cellular and Integrative Physiology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Gregory T. Collins
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
- South Texas Veterans Health Care System, San Antonio, TX, USA
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Beasley MM, Pilz EM, Kearns DN. A test of the role of stimulus-response and stimulus-outcome associations in the effects of intermittent-access training. Behav Processes 2024; 214:104984. [PMID: 38103808 PMCID: PMC10842382 DOI: 10.1016/j.beproc.2023.104984] [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: 07/25/2023] [Revised: 10/24/2023] [Accepted: 12/12/2023] [Indexed: 12/19/2023]
Abstract
Increased reinforcer motivation in rats has been repeatedly demonstrated following intermittent-access (IntA) training, where the reinforcer is only available for brief periods during a session, compared to continuous-access (ContA) training where the reinforcer is available throughout the session. The present study investigated whether different associations learned during training on the two procedures contributes to the effect. Two experiments tested the importance of the stimulus-response (S-R) and stimulus-outcome (S-O) associations between the IntA availability cues and the training response and reinforcer, respectively. In Exp. 1, separate groups of rats were trained to lever press for saccharin on the IntA or ContA procedures. Increased motivation for saccharin was observed in the IntA group on a later progressive ratio test where nosepoking was the operant (but not when lever pressing was the operant). The outcome of the nosepoke test suggests that a potential S-R association formed during IntA training was not critical for the effect. In Exp. 2, increased saccharin motivation (on nosepoke tests) after IntA training (with lever pressing) was observed regardless of the presence or absence of IntA availability cues, indicating that the S-O association formed during training is not critical for the effect either. Overall, these results suggest that the elemental associations learned on IntA procedures may not be what drives increased motivation observed after IntA training.
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Affiliation(s)
- Madeline M Beasley
- Psychology Department, American University, Washington, DC, United States
| | - Emma M Pilz
- Psychology Department, American University, Washington, DC, United States
| | - David N Kearns
- Psychology Department, American University, Washington, DC, United States.
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Robinson MJF, Bonmariage QSA, Samaha AN. Unpredictable, intermittent access to sucrose or water promotes increased reward pursuit in rats. Behav Brain Res 2023; 453:114612. [PMID: 37544370 DOI: 10.1016/j.bbr.2023.114612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 07/18/2023] [Accepted: 08/02/2023] [Indexed: 08/08/2023]
Abstract
Reward uncertainty can sensitize reward pathways, promoting increased reward-seeking and -taking behaviours. This is relevant to human conditions such as pathological gambling, eating disorders and drug addiction. In the context of addiction, preclinical self-administration procedures have been developed to model the intermittency of human drug use. These intermittent-access (IntA) procedures involve intermittent but predictable access to drug during self-administration sessions. However, human drug use typically involves intermittent and unpredictable drug access. We introduce a new procedure modeling unpredictable, intermittent access (UIntA) to a reinforcer, and we compare it to procedures that provide predictable reinforcer availability; continuous (ContA) or intermittent (IntA) access. Female rats self-administered water or liquid sucrose in daily hour-long sessions. IntA and ContA rats had access to a fixed volume of water or sucrose (0.1 ml), under a fixed ratio 3 schedule of reinforcement. IntA rats had predictable 5-min reinforcer ON and 25-min reinforcer OFF periods. ContA rats had 60 min of reinforcer access during each session. For UIntA rats, variation in the length of ON and OFF periods (1, 5 or 9 min/period), response requirement (variable ratio 3 schedule of reinforcement), reinforcer probability (50%) and quantity (0, 0.1 or 0.2 ml) introduced reward uncertainty. Following 14 daily self-administration sessions, UIntA rats showed the highest levels of responding for water or sucrose under progressive ratio conditions, responding under extinction conditions, and cue-induced reinstatement of sucrose seeking. Thus, unpredictable, intermittent reward access promotes increased reward pursuit. This has implications for modeling addiction and other disorders of increased reward seeking.
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Affiliation(s)
- Mike J F Robinson
- Department of Pharmacology and Physiology, Faculty of Medicine, Université de Montréal, Montréal, QC H3T 1J4, Canada
| | - Qi Shan A Bonmariage
- Department of Neurosciences, Faculty of Medicine, Université de Montréal, Montréal, QC H3T 1J4, Canada
| | - Anne-Noël Samaha
- Department of Pharmacology and Physiology, Faculty of Medicine, Université de Montréal, Montréal, QC H3T 1J4, Canada; Neural Signaling and Circuitry Research Group (SNC), Faculty of Medicine, Université de Montréal, Montréal, QC H3T 1J4, Canada; Center for Interdisciplinary Research on the Brain and Learning (CIRCA), Université de Montréal, Montréal, QC H3T 1J4, Canada; Neuroscience and Mental Health Strategy of the Université de Montréal (SENSUM), Université de Montréal, Montréal, QC H3T 1J4, Canada.
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Urueña-Méndez G, Dimiziani A, Bellés L, Goutaudier R, Ginovart N. Repeated Cocaine Intake Differentially Impacts Striatal D 2/3 Receptor Availability, Psychostimulant-Induced Dopamine Release, and Trait Behavioral Markers of Drug Abuse. Int J Mol Sci 2023; 24:13238. [PMID: 37686044 PMCID: PMC10487888 DOI: 10.3390/ijms241713238] [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: 08/10/2023] [Revised: 08/17/2023] [Accepted: 08/23/2023] [Indexed: 09/10/2023] Open
Abstract
Current research indicates that altered dopamine (DA) transmission in the striatum contributes to impulsivity and novelty-seeking, and it may mediate a link concerning a higher susceptibility to drug abuse. Whether increased susceptibility to drug abuse results from a hyperdopaminergic or hypodopaminergic state is still debated. Here, we simultaneously tracked changes in DA D2/3 receptor (D2/3R) availability and amphetamine-(AMPH)-induced DA release in relation to impulsivity and novelty-seeking prior to, and following, cocaine self-administration (SA) in Roman high- (RHA) and low- (RLA) avoidance rats. We found that high-impulsive/high novelty-seeking RHA rats exhibited lower D2/3R availabilities and higher AMPH-induced DA release in the striatum that predicted higher levels of cocaine intake compared with RLAs. Cocaine SA did not alter striatal D2/3R availability or impulsivity in RHA or RLA rats. Critically, cocaine exposure led to a baseline-dependent blunting of stimulated DA release in high-impulsive/high novelty-seeking RHA rats only, and to a baseline-dependent increase in novelty-seeking in low-impulsive/low novelty-seeking RLA rats only. Altogether, we propose that susceptibility to drug abuse results from an innate hyper-responsive DA system, promoting impulsive action and novelty-seeking, and producing stronger initial drug-reinforcing effects that contribute to the initiation and perpetuation of drug use. However, with repeated cocaine use, a tolerance to drug-induced striatal DA elevations develops, leading to a compensatory increase in drug consumption to overcome the reduced reward effects.
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Affiliation(s)
- Ginna Urueña-Méndez
- Department of Psychiatry, Faculty of Medicine, University of Geneva, 1211 Geneva, Switzerland; (G.U.-M.); (L.B.); (R.G.)
- Department of Basic Neurosciences, Faculty of Medicine, University of Geneva, 1211 Geneva, Switzerland
| | - Andrea Dimiziani
- Department of Psychiatry, Faculty of Medicine, University of Geneva, 1211 Geneva, Switzerland; (G.U.-M.); (L.B.); (R.G.)
| | - Lidia Bellés
- Department of Psychiatry, Faculty of Medicine, University of Geneva, 1211 Geneva, Switzerland; (G.U.-M.); (L.B.); (R.G.)
- Department of Basic Neurosciences, Faculty of Medicine, University of Geneva, 1211 Geneva, Switzerland
| | - Raphaël Goutaudier
- Department of Psychiatry, Faculty of Medicine, University of Geneva, 1211 Geneva, Switzerland; (G.U.-M.); (L.B.); (R.G.)
- Department of Basic Neurosciences, Faculty of Medicine, University of Geneva, 1211 Geneva, Switzerland
| | - Nathalie Ginovart
- Department of Psychiatry, Faculty of Medicine, University of Geneva, 1211 Geneva, Switzerland; (G.U.-M.); (L.B.); (R.G.)
- Department of Basic Neurosciences, Faculty of Medicine, University of Geneva, 1211 Geneva, Switzerland
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Salin A, Dugast E, Lardeux V, Solinas M, Belujon P. The amygdala-ventral pallidum pathway contributes to a hypodopaminergic state in the ventral tegmental area during protracted abstinence from chronic cocaine. Br J Pharmacol 2023; 180:1819-1831. [PMID: 36645812 DOI: 10.1111/bph.16034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 12/01/2022] [Accepted: 01/06/2023] [Indexed: 01/17/2023] Open
Abstract
BACKGROUND AND PURPOSE Incubation of craving, the progressive increase in drug seeking over the first weeks of abstinence, is associated with temporal changes during abstinence in the activity of several structures involved in drug-seeking behaviour. Decreases of dopamine (DA) release and DA neuronal activity (hypodopaminergic state) have been reported in the ventral tegmental area (VTA) during cocaine abstinence, but the mechanisms underlying these neuroadaptations are not well understood. We investigated the potential involvement of a VTA inhibiting circuit (basolateral amygdala [BLA]-ventral pallidum [VP] pathway) in the hypodopaminergic state associated with abstinence from chronic cocaine. EXPERIMENTAL APPROACH In a model of cocaine self-administration, we performed in vivo electrophysiological recordings of DA VTA neurons and BLA neurons from anaesthetised rats during early and protracted abstinence and evaluated the involvement of the BLA-VP pathway using a pharmacological approach. KEY RESULTS We found significant decreases in VTA DA population activity and significant increases in BLA activity after protracted but not after short-term abstinence from chronic cocaine. The decrease in VTA DA activity was restored by pharmacological inhibition of the activity of either the BLA or the VP, suggesting that these regions exert a negative influence on DA activity. CONCLUSION AND IMPLICATIONS Our study sheds new lights on neuroadaptations occurring during incubation of craving leading to relapse. In particular, we describe the involvement of the BLA-VP pathway in cocaine-induced decreases of DA activity in the VTA. This study adds important information about the specific brain network dysfunctions underlying hypodopaminergic activity during abstinence.
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Affiliation(s)
- Adélie Salin
- Université de Poitiers, INSERM, U-1084, Laboratoire des Neurosciences Expérimentales et Cliniques, Poitiers, France
- Université de Rennes, Institut Numecan INRAE, INSERM, Rennes, France
| | - Emilie Dugast
- Université de Poitiers, INSERM, U-1084, Laboratoire des Neurosciences Expérimentales et Cliniques, Poitiers, France
- CHU de Poitiers, Poitiers, France
| | - Virginie Lardeux
- Université de Poitiers, INSERM, U-1084, Laboratoire des Neurosciences Expérimentales et Cliniques, Poitiers, France
| | - Marcello Solinas
- Université de Poitiers, INSERM, U-1084, Laboratoire des Neurosciences Expérimentales et Cliniques, Poitiers, France
| | - Pauline Belujon
- Université de Poitiers, INSERM, U-1084, Laboratoire des Neurosciences Expérimentales et Cliniques, Poitiers, France
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Bender BN, Torregrossa MM. Intermittent cocaine self-administration has sex-specific effects on addiction-like behaviors in rats. Neuropharmacology 2023; 230:109490. [PMID: 36889433 PMCID: PMC10040443 DOI: 10.1016/j.neuropharm.2023.109490] [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: 12/19/2022] [Revised: 02/21/2023] [Accepted: 03/03/2023] [Indexed: 03/08/2023]
Abstract
Intermittent access (IntA) models of cocaine self-administration were developed to better model in rodents how cocaine is used by human drug users. Compared to traditional continuous access (ContA) models, IntA has been shown to enhance several pharmacological and behavioral effects of cocaine, but few studies have examined sex differences in IntA. Moreover, no one has examined the efficacy of cue extinction to reduce cocaine seeking in the IntA model, which has previously shown to be ineffective in other models that promote habit-like cocaine seeking. Therefore, rats were implanted with jugular vein catheters and dorsolateral striatum (DLS) cannulae and trained to self-administer cocaine paired with an audiovisual cue with ContA or IntA. In subsets of rats, we evaluated: the ability of Pavlovian cue extinction to reduce cue-induced drug seeking; motivation for cocaine using a progressive ratio procedure; punishment-resistant cocaine taking by pairing cocaine infusions with footshocks; and dependence of drug-seeking on DLS dopamine (a measure of habit-like behavior) with the dopamine antagonist cis-flupenthixol. Overall, cue extinction reduced cue-induced drug seeking after ContA or IntA. Compared to ContA, IntA resulted in increased motivation for cocaine exclusively in females, but IntA facilitated punished cocaine self-administration exclusively in males. After 10 days of IntA training, but not fewer, drug-seeking was dependent on DLS dopamine most notably in males. Our results suggest that IntA may be valuable for identifying sex differences in the early stages of drug use and provide a foundation for the investigation of the mechanisms involved.
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Affiliation(s)
- Brooke N Bender
- Department of Psychiatry, University of Pittsburgh, 450 Technology Drive, Pittsburgh, PA, 15219, USA; Center for Neuroscience, University of Pittsburgh, 4200 Fifth Ave, Pittsburgh, PA, 15213, USA
| | - Mary M Torregrossa
- Department of Psychiatry, University of Pittsburgh, 450 Technology Drive, Pittsburgh, PA, 15219, USA; Center for Neuroscience, University of Pittsburgh, 4200 Fifth Ave, Pittsburgh, PA, 15213, USA.
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Gage GA, Muench MA, Jee C, Kearns DN, Chen H, Tunstall BJ. Intermittent-access operant alcohol self-administration promotes binge-like drinking and drinking despite negative consequences in male and female heterogeneous stock rats. Neuropharmacology 2023; 235:109564. [PMID: 37149215 DOI: 10.1016/j.neuropharm.2023.109564] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Revised: 04/22/2023] [Accepted: 04/25/2023] [Indexed: 05/08/2023]
Abstract
The study of Alcohol Use Disorders (AUD) in preclinical models is hampered by difficulty in training rodents to voluntarily consume high levels of alcohol. The intermittency of alcohol access/exposure is well known to modulate alcohol consumption (e.g., alcohol deprivation effect, intermittent-access two-bottle-choice) and recently, intermittent access operant self-administration procedures have been used to produce more intense and binge-like self-administration of intravenous psychostimulant and opioid drugs. In the present study, we sought to systematically manipulate the intermittency of operant self-administered alcohol access to determine the feasibility of promoting more intensified, binge-like alcohol consumption. To this end, 24 male and 23 female NIH Heterogeneous Stock rats were trained to self-administer 10% w/v ethanol, before being split into three different-access groups. Short Access (ShA) rats continued receiving 30-min training sessions, Long Access (LgA) rats received 16-h sessions, and Intermittent Access (IntA) rats received 16-h sessions, wherein the hourly alcohol-access periods were shortened over sessions, down to 2 min. IntA rats demonstrated an increasingly binge-like pattern of alcohol drinking in response to restriction of alcohol access, while ShA and LgA rats maintained stable intake. All groups were tested on orthogonal measures of alcohol-seeking and quinine-punished alcohol drinking. The IntA rats displayed the most punishment-resistant drinking. In a separate experiment, we replicated our main finding, that intermittent access promotes a more binge-like pattern of alcohol self-administration using 8 male and 8 female Wistar rats. In conclusion, intermittent access to self-administered alcohol promotes more intensified self-administration. This approach may be useful in developing preclinical models of binge-like alcohol consumption in AUD.
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Affiliation(s)
- Grey A Gage
- Department of Pharmacology, Addiction Science and Toxicology, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Marissa A Muench
- Department of Pharmacology, Addiction Science and Toxicology, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Changhoon Jee
- Department of Pharmacology, Addiction Science and Toxicology, University of Tennessee Health Science Center, Memphis, TN, USA
| | - David N Kearns
- Psychology Department, American University, Washington, DC, USA
| | - Hao Chen
- Department of Pharmacology, Addiction Science and Toxicology, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Brendan J Tunstall
- Department of Pharmacology, Addiction Science and Toxicology, University of Tennessee Health Science Center, Memphis, TN, USA.
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Beasley MM, Tunstall BJ, Kearns DN. Intermittent access cocaine self-administration produces context-specific escalation and increased motivation. Drug Alcohol Depend 2023; 245:109797. [PMID: 36801708 PMCID: PMC10033440 DOI: 10.1016/j.drugalcdep.2023.109797] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 01/27/2023] [Accepted: 02/01/2023] [Indexed: 02/05/2023]
Abstract
The intermittent-access (IntA) self-administration procedure has been reported to produce intensified addiction-like behavior compared to continuous-access (ContA) procedures. In a common variation of the IntA procedure, cocaine is available for 5 min at the beginning of each half hour of a 6-h session. In contrast, during ContA procedures, cocaine is available continuously throughout a session, typically lasting one or more hours. Previous studies comparing procedures have used between-subjects designs, where separate groups of rats self-administer cocaine on either IntA or ContA procedures. The present study used a within-subjects design where subjects self-administered cocaine on the IntA procedure in one context and self-administered cocaine on the continuous short-access (ShA) procedure in another context during separate sessions. Across sessions, rats escalated cocaine intake in the IntA, but not ShA, context. Following sessions eight and 11, rats were administered a progressive ratio test in each context to monitor the change in cocaine motivation. Rats obtained more cocaine infusions on the progressive ratio test in the IntA context than in the ShA context following 11 sessions. These results suggest that addiction-like behaviors following IntA self-administration may be influenced by context-specific learning factors.
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Affiliation(s)
| | - Brendan J Tunstall
- Department of Pharmacology, Addiction Science, and Toxicology, University of Tennessee Health Sciences Center, Memphis, TN, USA
| | - David N Kearns
- Psychology Department, American University, Washington, DC, USA
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10
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Saraswat AA, Longyear LG, Kawa AB, Ferrario CR. Cocaine-induced plasticity, motivation, and cue responsivity do not differ in obesity-prone vs obesity-resistant rats; implications for food addiction. Psychopharmacology (Berl) 2023; 240:853-870. [PMID: 36806961 PMCID: PMC10006066 DOI: 10.1007/s00213-023-06327-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Accepted: 01/25/2023] [Indexed: 02/20/2023]
Abstract
RATIONALE Compared to obesity-resistant rats, obesity-prone rats consume more food, work harder to obtain food, show greater motivational responses to food-cues, and show greater striatal plasticity in response to eating sugary/fatty foods. Therefore, it is possible that obesity-prone rats may also be more sensitive to the motivational properties of cocaine and cocaine-paired cues, and to plasticity induced by cocaine. OBJECTIVE To examine baseline differences in motivation for cocaine and effects of intermittent access (IntA) cocaine self-administration on cocaine motivation, neurobehavioral responsivity to cocaine-paired cues, and locomotor sensitization in male obesity-prone vs obesity-resistant rats. METHODS Intravenous cocaine self-administration was used to examine drug-taking and drug-seeking in males. Motivation for cocaine was measured using a within session threshold procedure. Cue-induced c-Fos expression in mesocorticolimbic regions was measured. RESULTS Drug-taking and drug-seeking, cue-induced c-Fos, locomotor sensitization, and preferred level of cocaine consumption (Q0) were similar between obesity-prone and obesity-resistant groups. Maximal responding during demand testing (Rmax) was lower in obesity-prone rats. IntA experience enhanced motivation for cocaine (Pmax) in obesity-prone rats. CONCLUSIONS The results do not support robust inherent differences in motivation for cocaine, cue-induced cocaine seeking, or neurobehavioral plasticity induced by IntA in obesity-prone vs obesity-resistant rats. This contrasts with previously established differences seen for food and food cues in these populations and shows that inherent enhancements in motivation for food and food-paired cues do not necessarily transfer to drugs and drug-paired cues.
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Affiliation(s)
- Anish A Saraswat
- Department of Pharmacology, University of Michigan, Ann Arbor, MI, 48109, USA
- Psychology Department (Biopsychology), University of Michigan, Ann Arbor, MI, 48109, USA
| | - Lauren G Longyear
- Psychology Department (Biopsychology), University of Michigan, Ann Arbor, MI, 48109, USA
| | - Alex B Kawa
- Psychology Department (Biopsychology), University of Michigan, Ann Arbor, MI, 48109, USA
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Carrie R Ferrario
- Department of Pharmacology, University of Michigan, Ann Arbor, MI, 48109, USA.
- Psychology Department (Biopsychology), University of Michigan, Ann Arbor, MI, 48109, USA.
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Beasley MM, Gunawan T, Tunstall BJ, Kearns DN. Intermittent access training produces greater motivation for a non-drug reinforcer than long access training. Learn Behav 2022; 50:509-523. [PMID: 35132517 PMCID: PMC10237344 DOI: 10.3758/s13420-022-00512-w] [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] [Accepted: 01/16/2022] [Indexed: 01/01/2023]
Abstract
It has recently been proposed that the intermittent access (IntA) drug self-administration procedure better produces behavioral changes relevant to addiction than the long access (LgA) procedure. In this version of the IntA procedure, the drug is made available for a 5-min period during each half hour of a 6-h session. In contrast, on the LgA procedure, the drug is available continuously for 6 h. Previous studies have found that IntA drug self-administration produces greater drug motivation, measured by increased progressive ratio breakpoints, than LgA self-administration. It has been hypothesized that this effect is due to the rapid, "spiking" brain levels of the drug, and consequent neuroadaptations, experienced by rats during IntA sessions. However, no study has compared the effects of IntA versus LgA training on reinforcer motivation when using a non-drug reinforcer. The present study compared motivation for a saccharin reinforcer after IntA or LgA training. In Experiment 1, separate groups of rats lever-pressed for saccharin on the IntA or LgA procedures. In Experiment 2, a within-subjects design was used where rats pressed one lever on the IntA procedure and another lever on the LgA procedure for saccharin. In both experiments, IntA training produced greater breakpoints than LgA training. As no drug was used here, spiking drug levels could not have been responsible for the increased saccharin motivation observed after IntA training. Instead, it is proposed that differences in stimulus-reinforcer associations learned during IntA versus LgA training may be responsible for the effect. Future research is needed to determine the extent to which such learning factors may contribute to the increased motivation observed after IntA training with drug reinforcers.
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Affiliation(s)
- Madeline M Beasley
- Psychology Department, American University, 4400 Massachusetts Ave NW, Washington, DC, 20016, USA.
| | - Tommy Gunawan
- Human Psychopharmacology Laboratory, NIH/NIAAA, Bethesda, MD, USA
| | - Brendan J Tunstall
- Department of Pharmacology, Addiction Science, and Toxicology, University of Tennessee Health Sciences Center, Memphis, TN, USA
| | - David N Kearns
- Psychology Department, American University, 4400 Massachusetts Ave NW, Washington, DC, 20016, USA
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12
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Within versus between group designs, and not timing of onset of puberty, influence sex and age differences in intake of palatable food in rats. Physiol Behav 2022; 257:113997. [DOI: 10.1016/j.physbeh.2022.113997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 10/11/2022] [Accepted: 10/13/2022] [Indexed: 11/05/2022]
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13
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D-amphetamine maintenance therapy reduces cocaine use in female rats. Psychopharmacology (Berl) 2022; 239:3755-3770. [PMID: 36357743 DOI: 10.1007/s00213-022-06271-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 10/19/2022] [Indexed: 11/12/2022]
Abstract
RATIONALE D-amphetamine maintenance therapy is a promising strategy to reduce drug use in cocaine use disorder (addiction). In both male rats and human cocaine users, d-amphetamine treatment reduces cocaine-taking and -seeking. However, this has not been examined systematically in female animals, even though cocaine addiction afflicts both sexes, and the sexes can differ in their response to cocaine. OBJECTIVES We determined how d-amphetamine maintenance therapy during cocaine self-administration influences cocaine use in female rats. METHODS In experiment 1, two groups of female rats received 14 intermittent access (IntA) cocaine self-administration sessions. One group received concomitant d-amphetamine maintenance treatment (COC + A rats; 5 mg/kg/day, via minipump), the other group did not (COC rats). After discontinuing d-amphetamine treatment, we measured responding for cocaine under a progressive ratio schedule, responding under extinction, and cocaine-primed reinstatement of drug-seeking. In experiment 2, we assessed the effects of d-amphetamine maintenance on these measures in already IntA cocaine-experienced rats. Thus, rats first received 14 IntA cocaine self-administration sessions without d-amphetamine. They then received 14 more IntA sessions, now either with (COC/COC + A rats) or without (COC/COC rats) concomitant d-amphetamine treatment. RESULTS In both experiments, d-amphetamine treatment did not significantly influence ongoing cocaine self-administration behaviour. After d-amphetamine treatment cessation, cocaine-primed reinstatement of cocaine-seeking was also unchanged. However, after d-amphetamine treatment cessation, rats responded less for cocaine both under progressive ratio and extinction conditions. CONCLUSIONS D-amphetamine treatment can both prevent and reverse increases in the motivation to take and seek cocaine in female animals.
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14
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James MH, Aston-Jones G. Orexin Reserve: A Mechanistic Framework for the Role of Orexins (Hypocretins) in Addiction. Biol Psychiatry 2022; 92:836-844. [PMID: 36328706 PMCID: PMC10184826 DOI: 10.1016/j.biopsych.2022.06.027] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 06/07/2022] [Accepted: 06/23/2022] [Indexed: 11/22/2022]
Abstract
In 2014, we proposed that orexin signaling transformed motivationally relevant states into adaptive behavior directed toward exploiting an opportunity or managing a threat, a process we referred to as motivational activation. Advancements in animal models since then have permitted higher-resolution measurements of motivational states; in particular, the behavioral economics approach for studying drug demand characterizes conditions that lead to the enhanced motivation that underlies addiction. This motivational plasticity is paralleled by persistently increased orexin expression in a topographically specific manner-a finding confirmed across species, including in humans. Normalization of orexin levels also reduces drug motivation in addiction models. These new advancements lead us to update our proposed framework for the orexin function. We now propose that the capacity of orexin neurons to exhibit dynamic shifts in peptide production contributes to their role in adaptive motivational regulation and that this is achieved via a pool of reserve orexin neurons. This reserve is normally bidirectionally recruited to permit motivational plasticity that promotes flexible, adaptive behavior. In pathological states such as addiction, however, we propose that the orexin system loses capacity to adaptively adjust peptide production, resulting in focused hypermotivation for drug, driven by aberrantly and persistently high expression in the orexin reserve pool. This mechanistic framework has implications for the understanding and treatment of several psychiatric disorders beyond addiction, particularly those characterized by motivational dysfunction.
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Affiliation(s)
- Morgan H James
- Brain Health Institute, Rutgers University and Rutgers Biomedical and Health Sciences, Piscataway, New Jersey; Department of Psychiatry, Robert Wood Johnson Medical School, Rutgers University and Rutgers Biomedical and Health Sciences, Piscataway, New Jersey.
| | - Gary Aston-Jones
- Brain Health Institute, Rutgers University and Rutgers Biomedical and Health Sciences, Piscataway, New Jersey; Department of Psychiatry, Robert Wood Johnson Medical School, Rutgers University and Rutgers Biomedical and Health Sciences, Piscataway, New Jersey.
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15
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Samson KR, Xu W, Kortagere S, España RA. Intermittent access to oxycodone decreases dopamine uptake in the nucleus accumbens core during abstinence. Addict Biol 2022; 27:e13241. [PMID: 36301217 PMCID: PMC10262085 DOI: 10.1111/adb.13241] [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: 02/25/2022] [Revised: 07/29/2022] [Accepted: 09/27/2022] [Indexed: 01/24/2023]
Abstract
A major obstacle in treating opioid use disorder is the persistence of drug seeking or craving during periods of abstinence, which is believed to contribute to relapse. Dopamine transmission in the mesolimbic pathway is posited to contribute to opioid reinforcement, but the processes by which dopamine influences drug seeking have not been completely elucidated. To examine whether opioid seeking during abstinence is associated with alterations in dopamine transmission, female and male rats self-administered oxycodone under an intermittent access schedule of reinforcement. Following self-administration, rats underwent a forced abstinence period, and cue-induced seeking tests were conducted to assess oxycodone seeking. One day following the final seeking test, rats were sacrificed to perform ex vivo fast scan cyclic voltammetry and western blotting in the nucleus accumbens. Rats displayed reduced dopamine uptake rate on abstinence day 2 and abstinence day 15, compared to oxycodone-naïve rats. Further, on abstinence day 15, rats had reduced phosphorylation of the dopamine transporter. Additionally, local application of oxycodone to the nucleus accumbens reduced dopamine uptake in oxycodone-naïve rats and in rats during oxycodone abstinence, on abstinence day 2 and abstinence day 15. These observations suggest that abstinence from oxycodone results in dysfunctional dopamine transmission, which may contribute to sustained oxycodone seeking during abstinence.
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Affiliation(s)
- Kyle R. Samson
- Drexel University College of Medicine, Department of Neurobiology and Anatomy
| | - Wei Xu
- Drexel University College of Medicine, Department of Microbiology and Immunology
| | - Sandhya Kortagere
- Drexel University College of Medicine, Department of Microbiology and Immunology
| | - Rodrigo A. España
- Drexel University College of Medicine, Department of Neurobiology and Anatomy
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16
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Alonso IP, O'Connor BM, Bryant KG, Mandalaywala RK, España RA. Incubation of cocaine craving coincides with changes in dopamine terminal neurotransmission. ADDICTION NEUROSCIENCE 2022; 3. [PMID: 36081573 PMCID: PMC9451023 DOI: 10.1016/j.addicn.2022.100029] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Relapse to drug use is one of the major challenges in treating substance use disorders. Exposure to drug-related cues and contexts triggers drug craving, which drives cocaine seeking, and increases the probability of relapse. Clinical and animal studies have shown a progressive intensification of cocaine seeking and craving that develops over the course of abstinence, a phenomenon commonly referred to as incubation of cocaine craving. Although the neurobiology underlying incubation of cocaine craving has been examined – particularly within the context of glutamate plasticity– the extent to which increased cocaine craving engenders mesolimbic dopamine (DA) changes has received relatively little attention. To assess whether incubation of cocaine craving is associated with alterations in DA terminal neurotransmission in the nucleus accumbens core (NAc), we used ex vivo fast scan cyclic voltammetry in female and male rats to assess DA dynamics following short access, long access, or intermittent access to cocaine self-administration followed by 28 days of abstinence. Results indicated that both long access and intermittent access to cocaine produced robust incubation of cocaine craving, which was associated with increases in cocaine potency. In addition, intermittent access self-administration also produced a robust increase in DA uptake rate at baseline. In contrast, short access to cocaine did not engender incubation of cocaine craving, nor produce changes in DA neurotransmission. Together these observations indicate that incubation of cocaine craving coincides with changes in DA transmission, suggesting that underlying changes in mesolimbic DA signaling may contribute to the progressive intensification of drug craving that occurs across periods of abstinence.
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17
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O'Connor RM, Kenny PJ. Utility of 'substance use disorder' as a heuristic for understanding overeating and obesity. Prog Neuropsychopharmacol Biol Psychiatry 2022; 118:110580. [PMID: 35636576 DOI: 10.1016/j.pnpbp.2022.110580] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 05/24/2022] [Accepted: 05/24/2022] [Indexed: 02/07/2023]
Abstract
Rates of obesity and obesity-associated diseases have increased dramatically in countries with developed economies. Substance use disorders (SUDs) are characterized by the persistent use of the substance despite negative consequences. It has been hypothesized that overconsumption of palatable energy dense food can elicit SUD-like maladaptive behaviors that contribute to persistent caloric intake beyond homeostatic need even in the face of negative consequences. Palatable food and drugs of abuse act on many of the same motivation-related circuits in the brain, and can induce, at least superficially, similar molecular, cellular, and physiological adaptations on these circuits. As such, applying knowledge about the neurobiological mechanisms of SUDs may serve as useful heuristic to better understand the persistent overconsumption of palatable food that contributes to obesity. However, many important differences exist between the actions of drugs of abuse and palatable food in the brain. This warrants caution when attributing weight gain and obesity to the manifestation of a putative SUD-related behavioral disorder. Here, we describe similarities and differences between compulsive drug use in SUDs and overconsumption in obesity and consider the merit of the concept of "food addiction".
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Affiliation(s)
- Richard M O'Connor
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, United States of America
| | - Paul J Kenny
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, United States of America.
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18
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O’Connor SL, Aston-Jones G, James MH. Novelty preference does not predict trait cocaine behaviors in male rats. ADDICTION NEUROSCIENCE 2022; 2:100013. [PMID: 35425947 PMCID: PMC9004685 DOI: 10.1016/j.addicn.2022.100013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Heightened novelty seeking is a risk factor for the initiation of drug use and development of substance use disorders. In rats, novelty seeking can be examined by assessing preference for a novel environment. Some evidence indicates that high novelty preferring (HNP) rats have higher drug intake compared to low novelty preferring (LNP) rats, although these data are mixed. Moreover, the extent to which the HNP phenotype can predict other initial drug behaviors, including economic demand for cocaine, has not been tested. Here, we screened a cohort (n=60) of male rats for novelty preference and several subsequent cocaine behaviors, including locomotor reactivity to a cocaine priming injection, acquisition of cocaine self-administration, as well as cocaine demand using a within-session behavioral economics procedure. Novelty preference did not correlate with cocaine behaviors, nor were there any differences between HNP and LNP rats identified using a median split strategy. Moreover, regression analyses indicated that novelty preference did not have predictive utility for any of the cocaine behaviors tested. Thus, the extent to which the novelty preference trait can predict initial cocaine-related behaviors in male rats may be limited. This is in contrast to the novel locomotor reactivity phenotype, which is strongly linked with initial cocaine intake, indicating that these traits are distinct and differentially predict cocaine behaviors in rats.
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Affiliation(s)
- Shayna L. O’Connor
- Department of Psychiatry, Robert Wood Johnson Medical School, Rutgers University and Rutgers Biomedical Health Sciences, Piscataway, New Jersey, USA
- Brain Health Institute, Rutgers University and Rutgers Biomedical and Health Sciences, Piscataway, New Jersey, USA
| | - Gary Aston-Jones
- Department of Psychiatry, Robert Wood Johnson Medical School, Rutgers University and Rutgers Biomedical Health Sciences, Piscataway, New Jersey, USA
- Brain Health Institute, Rutgers University and Rutgers Biomedical and Health Sciences, Piscataway, New Jersey, USA
| | - Morgan H. James
- Department of Psychiatry, Robert Wood Johnson Medical School, Rutgers University and Rutgers Biomedical Health Sciences, Piscataway, New Jersey, USA
- Brain Health Institute, Rutgers University and Rutgers Biomedical and Health Sciences, Piscataway, New Jersey, USA
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19
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Nicolas C, Russell TI, Shaham Y, Ikemoto S. Dissociation Between Incubation of Cocaine Craving and Anxiety-Related Behaviors After Continuous and Intermittent Access Self-Administration. Front Neurosci 2022; 15:824741. [PMID: 35197820 PMCID: PMC8859112 DOI: 10.3389/fnins.2021.824741] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 12/27/2021] [Indexed: 12/01/2022] Open
Abstract
Studies using either continuous or intermittent access cocaine self-administration procedures showed that cocaine seeking increases during abstinence (incubation of cocaine craving), and that this effect is higher after intermittent cocaine access. Other studies showed that cocaine abstinence is characterized by the emergence of stress- and anxiety-related states which were hypothesized to increase relapse vulnerability. We examined whether incubation of cocaine craving and anxiety-related behaviors are correlated and whether intermittent cocaine self-administration would potentiate these behaviors during abstinence. Male rats self-administered cocaine either continuously (6 h/day) or intermittently (5 min ON, 25 min OFF × 12) for 14 days, followed by relapse tests after 1 or 21 abstinence days. A group of rats that self-administered saline served as a control. Anxiety-related behaviors were measured on the same abstinence days, using the novelty induced-hypophagia test. Finally, motivation for cocaine was measured using a progressive ratio reinforcement schedule. Lever-presses after 21 abstinence days were higher than after 1 day and this incubation effect was higher in the intermittent access group. Progressive ratio responding was also higher after intermittent cocaine access. Intermittent and continuous cocaine access did not induce anxiety-like responses in the novelty-induced hypophagia test after 1 or 21 abstinence days. Independent of the access condition, incubation of cocaine seeking was not correlated with the novelty-induced hypophagia measures. Results suggest that cocaine-induced anxiety-related states during protracted abstinence do not contribute to incubation of cocaine craving. However, this conclusion is tentative because we used a single anxiety-related measure and did not test female rats.
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20
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Brown RM, Dayas C, James M, Smith RJ. New directions in modelling dysregulated reward seeking for food and drugs. Neurosci Biobehav Rev 2022; 132:1037-1048. [PMID: 34736883 PMCID: PMC8816817 DOI: 10.1016/j.neubiorev.2021.10.043] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 10/08/2021] [Accepted: 10/19/2021] [Indexed: 01/03/2023]
Abstract
Behavioral models are central to behavioral neuroscience. To study the neural mechanisms of maladaptive behaviors (including binge eating and drug addiction), it is essential to develop and utilize appropriate animal models that specifically focus on dysregulated reward seeking. Both food and cocaine are typically consumed in a regulated manner by rodents, motivated by reward and homeostatic mechanisms. However, both food and cocaine seeking can become dysregulated, resulting in binge-like consumption and compulsive patterns of intake. The speakers in this symposium for the 2021 International Behavioral Neuroscience Meeting utilize behavioral models of dysregulated reward-seeking to investigate the neural mechanisms of binge-like consumption, enhanced cue-driven reward seeking, excessive motivation, and continued use despite negative consequences. In this review, we outline examples of maladaptive patterns of intake and explore recent animal models that drive behavior to become dysregulated, including stress exposure and intermittent access to rewards. Lastly, we explore select behavioral and neural mechanisms underlying dysregulated reward-seeking for both food and drugs.
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Affiliation(s)
- Robyn M Brown
- Department of Biochemistry and Pharmacology, University of Melbourne, Parkville, Vic, 3052, Australia.,Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Vic, 3052, Australia.,Correspondence: Morgan James, Department of Psychiatry, 683 Hoes Ln West, Office 164, Rutgers University, Piscataway, NJ, 08854 USA, Ph: +1 732 235 4767, , Robyn M Brown, Department of Biochemistry and Pharmacology, Medical Building (B181), Level 8, The University of Melbourne, Parkville VIC 3010 Australia, Ph: +61401007008,
| | - Christopher Dayas
- School of Biomedical Sciences & Pharmacy, Faculty of Health, University of Newcastle, Callaghan, NSW, Australia,Hunter Medical Research Institute, New Lambton Heights, NSW, Australia
| | - Morgan James
- Department of Psychiatry, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ, 08854, USA,Brain Health Institute, Rutgers University, Piscataway, NJ, 08854, USA,Correspondence: Morgan James, Department of Psychiatry, 683 Hoes Ln West, Office 164, Rutgers University, Piscataway, NJ, 08854 USA, Ph: +1 732 235 4767, , Robyn M Brown, Department of Biochemistry and Pharmacology, Medical Building (B181), Level 8, The University of Melbourne, Parkville VIC 3010 Australia, Ph: +61401007008,
| | - Rachel J Smith
- Department of Psychological & Brain Sciences, Institute for Neuroscience, Texas A&M University, College Station, TX, 77843, USA
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21
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Individual differences in dopamine uptake in the dorsomedial striatum prior to cocaine exposure predict motivation for cocaine in male rats. Neuropsychopharmacology 2021; 46:1757-1767. [PMID: 33953341 PMCID: PMC8357974 DOI: 10.1038/s41386-021-01009-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 03/27/2021] [Accepted: 03/31/2021] [Indexed: 11/08/2022]
Abstract
A major theme of addiction research has focused on the neural substrates of individual differences in the risk for addiction; however, little is known about how vulnerable populations differ from those that are relatively protected. Here, we prospectively measured dopamine (DA) neurotransmission prior to cocaine exposure to predict the onset and course of cocaine use. Using in vivo voltammetry, we first generated baseline profiles of DA release and uptake in the dorsomedial striatum (DMS) and nucleus accumbens of drug-naïve male rats prior to exposing them to cocaine using conditioned place preference (CPP) or operant self-administration. We found that the innate rate of DA uptake in the DMS strongly predicted motivation for cocaine and drug-primed reinstatement, but not CPP, responding when "price" was low, or extinction. We then assessed the impact of baseline variations in DA uptake on cocaine potency in the DMS using ex vivo voltammetry in naïve rats and in rats with DA transporter (DAT) knockdown. DA uptake in the DMS of naïve rats predicted the neurochemical response to cocaine, such that rats with innately faster rates of DA uptake demonstrated higher cocaine potency at the DAT and rats with DAT knockdown displayed reduced potency compared to controls. Together, these data demonstrate that inherent variability in DA uptake in the DMS predicts the behavioral response to cocaine, potentially by altering the apparent potency of cocaine.
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22
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Nguyen JD, Grant Y, Taffe MA. Paradoxical changes in brain reward status during oxycodone self-administration in a novel test of the negative reinforcement hypothesis. Br J Pharmacol 2021; 178:3797-3812. [PMID: 33948939 PMCID: PMC8387405 DOI: 10.1111/bph.15520] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 04/18/2021] [Accepted: 04/20/2021] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND AND PURPOSE The extra medical use of, and addiction to, prescription opioid analgesics is a growing health problem. To characterize how prescription opioid abuse develops, this study investigated the affective consequences of escalating prescription opioid use using intracranial self-stimulation (ICSS) reward and oxycodone intravenous self-administration (IVSA) models. EXPERIMENTAL APPROACH Male Wistar rats were given access to oxycodone IVSA (0.15 mg·kg-1 per infusion, i.v.) in short-access (ShA; 1 h) or long-access (LgA; 12 h) sessions for five sessions per week followed by intermittent 60-h discontinuations from drug access, a novel explicit test of the negative reinforcement hypothesis. Separate groups were first trained in the ICSS procedure and then in oxycodone IVSA in 11-h LgA sessions. KEY RESULTS Rats given LgA to oxycodone escalated their responding more than ShA rats, with further significant increases observed following each 60-h discontinuation. Presession brain reward thresholds increased with sequential daily LgA IVSA sessions, consistent with a growing negative affective state consequent to successive daily intoxication/abstinence cycles. A 1-h oxycodone IVSA interval was sufficient to normalize these elevated reward thresholds, as was, paradoxically, a 60-h weekend abstinence. The increase in ICSS thresholds was attenuated in a group treated with the long-acting κ-opioid antagonist norbinaltorphimine prior to IVSA training. CONCLUSION AND IMPLICATIONS Changes in brain reward function during escalation of oxycodone self-administration are driven by an interplay between κ-opioid receptor-mediated negative affective state associated with escalated oxycodone intake and dynamic restoration of brain reward status during longer periods of abstinence.
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Affiliation(s)
- Jacques D. Nguyen
- Department of Neuroscience, The Scripps Research Institute, La Jolla, CA USA
- Department of Psychiatry, University of California San Diego, La Jolla, CA USA
| | - Yanabel Grant
- Department of Neuroscience, The Scripps Research Institute, La Jolla, CA USA
- Department of Psychiatry, University of California San Diego, La Jolla, CA USA
| | - Michael A. Taffe
- Department of Neuroscience, The Scripps Research Institute, La Jolla, CA USA
- Department of Psychiatry, University of California San Diego, La Jolla, CA USA
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23
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Fragale JE, James MH, Aston‐Jones G. Intermittent self-administration of fentanyl induces a multifaceted addiction state associated with persistent changes in the orexin system. Addict Biol 2021; 26:e12946. [PMID: 32798290 DOI: 10.1111/adb.12946] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 06/10/2020] [Accepted: 07/11/2020] [Indexed: 12/14/2022]
Abstract
The orexin (hypocretin) system plays a critical role in motivated drug taking. Cocaine self-administration with the intermittent access (IntA) procedure produces a robust addiction-like state that is orexin-dependent. Here, we sought to determine the role of the orexin system in opioid addiction using IntA self-administration of fentanyl. Different groups of male rats were either given continuous access in 1-h period (short access [ShA]), 6-h period (long access [LgA]), or IntA (5 min of access separated by 25 min of no access for 6 h) to fentanyl for 14 days. IntA produced a greater escalation of fentanyl intake, increased motivation for fentanyl on a behavioral economics task, persistent drug seeking during abstinence, and stronger cue-induced reinstatement compared with rats given ShA or LgA. We found that addiction behaviors induced by IntA to fentanyl were reversed by the orexin-1 receptor antagonist SB-334867. IntA to fentanyl was also associated with a persistent increase in the number of orexin neurons. Together, these results indicate that the IntA model is a useful tool in the study of opioid addiction and that the orexin system is critical for the maintenance of addiction behaviors induced by IntA self-administration of fentanyl.
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Affiliation(s)
- Jennifer E. Fragale
- Brain Health Institute Rutgers University and Rutgers Biomedical and Health Sciences Piscataway New Jersey USA
| | - Morgan H. James
- Brain Health Institute Rutgers University and Rutgers Biomedical and Health Sciences Piscataway New Jersey USA
- Florey Institute of Neuroscience and Mental Health University of Melbourne Melbourne Victoria Australia
| | - Gary Aston‐Jones
- Brain Health Institute Rutgers University and Rutgers Biomedical and Health Sciences Piscataway New Jersey USA
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24
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Dopamine 'ups and downs' in addiction revisited. Trends Neurosci 2021; 44:516-526. [PMID: 33892963 DOI: 10.1016/j.tins.2021.03.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 01/14/2021] [Accepted: 03/16/2021] [Indexed: 12/11/2022]
Abstract
Repeated drug use can change dopamine (DA) function in ways that promote the development and persistence of addiction, but in what direction? By one view, drug use blunts DA neurotransmission, producing a hypodopaminergic state that fosters further drug use to overcome a DA deficiency. Another view is that drug use enhances DA neurotransmission, producing a sensitized, hyperdopaminergic reaction to drugs and drug cues. According to this second view, continued drug use is motivated by sensitization of drug 'wanting'. Here we discuss recent evidence supporting the latter view, both from preclinical studies using intermittent cocaine self-administration procedures that mimic human patterns of use and from related human neuroimaging studies. These studies have implications for the modeling of addiction in the laboratory and for treatment.
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25
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Alonso IP, Pino JA, Kortagere S, Torres GE, España RA. Dopamine transporter function fluctuates across sleep/wake state: potential impact for addiction. Neuropsychopharmacology 2021; 46:699-708. [PMID: 33032296 PMCID: PMC8026992 DOI: 10.1038/s41386-020-00879-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Revised: 09/13/2020] [Accepted: 09/15/2020] [Indexed: 12/20/2022]
Abstract
The dopamine transporter (DAT) has been implicated in a variety of arousal-related processes including the regulation of motor activity, learning, motivated behavior, psychostimulant abuse, and, more recently, sleep/wake state. We previously demonstrated that DAT uptake regulates fluctuations in extracellular dopamine (DA) in the striatum across the light/dark cycle with DA levels at their highest during the dark phase and lowest during the light phase. Despite this evidence, whether fluctuations in DA uptake across the light/dark cycle are associated with changes in sleep/wake has not been tested. To address this, we employed a combination of sleep/wake recordings, fast scan cyclic voltammetry, and western blotting to examine whether sleep/wake state and/or light/dark phase impact DA terminal neurotransmission in male rats. Further, we assessed whether variations in plasma membrane DAT levels and/or phosphorylation of the threonine 53 site on the DAT accounts for fluctuations in DA neurotransmission. Given the extensive evidence indicating that psychostimulants increase DA through interactions with the DAT, we also examined to what degree the effects of cocaine at inhibiting the DAT vary across sleep/wake state. Results demonstrated a significant association between individual sleep/wake states and DA terminal neurotransmission, with higher DA uptake rate, increased phosphorylation of the DAT, and enhanced cocaine potency observed after periods of sleep. These findings suggest that sleep/wake state influences DA neurotransmission in a manner that is likely to impact a host of DA-dependent processes including a variety of neuropsychiatric disorders.
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Affiliation(s)
- I. P. Alonso
- grid.166341.70000 0001 2181 3113Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129 USA
| | - J. A. Pino
- grid.440631.40000 0001 2228 7602Departamento de Medicina, Facultad de Medicina, Universidad de Atacama, 1532502 Copiapó, Chile
| | - S. Kortagere
- grid.166341.70000 0001 2181 3113Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA 19129 USA
| | - G. E. Torres
- grid.254250.40000 0001 2264 7145Department of Molecular, Cellular & Biomedical Sciences, CUNY School of Medicine at the City College of New York, New York, NY 10031 USA
| | - R. A. España
- grid.166341.70000 0001 2181 3113Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129 USA
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Assis MA, Díaz D, Ferrado R, Ávila-Zarza CA, Weruaga E, Ambrosio E. Transplantation with Lewis bone marrow induces the reinstatement of cocaine-seeking behavior in male F344 resistant rats. Brain Behav Immun 2021; 93:23-34. [PMID: 33278561 DOI: 10.1016/j.bbi.2020.11.039] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Revised: 10/27/2020] [Accepted: 11/22/2020] [Indexed: 01/14/2023] Open
Abstract
One of the main challenges to understand drug addiction is defining the biological mechanisms that underlie individual differences in recidivism. Studies of these mechanisms have mainly focused on the brain, yet we demonstrate here a significant influence of the peripheral immune system on this phenomenon. Lewis (LEW) and Fischer 344 (F344) rats have different immunological profiles and they display a distinct vulnerability to the reinforcing effects of cocaine, with F344 more resistant to reinstate cocaine-seeking behavior. Bone marrow from male LEW and F344 rats was transferred to male F344 rats (F344/LEW-BM and F344/F344-BM, respectively), and these rats were trained to self-administer cocaine over 21 days. Following extinction, these animals received a sub-threshold primer dose of cocaine to evaluate reinstatement. F344/LEW-BM but not F344/F344-BM rats reinstated cocaine-seeking behavior, in conjunction with changes in their peripheral immune cell populations to a profile that corresponded to that of the LEW donors. After cocaine exposure, higher CD4+ T-cells and lower CD4+CD25+ T-cells levels were observed in F344/LEW-BM rats referred to control, and the splenic expression of Il-17a, Tgf-β, Tlr-2, Tlr-4 and Il-1β was altered in both groups. We propose that peripheral T-cells respond to cocaine, with CD4+ T-cells in particular undergoing Th17 polarization and generating long-term memory, these cells releasing mediators that trigger central mechanisms to induce reinstatement after a second encounter. This immune response may explain the high rates of recidivism observed despite long periods of detoxification, shedding light on the mechanisms underlying the vulnerability and resilience of specific individuals, and opening new perspectives for personalized medicine in the treatment of relapse.
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Affiliation(s)
- María Amparo Assis
- Departamento de Psicobiología, Facultad de Psicología, Universidad Nacional de Educación a Distancia (UNED), Madrid, Spain; Facultad de Ciencias Médicas, Universidad Nacional de Santiago del Estero (UNSE), Santiago del Estero, Argentina; Laboratorio de Biología Molecular, Inmunología y Microbiología, Instituto Multidisciplinario de Salud, Tecnología y Desarrollo (IMSaTeD), CONICET-UNSE, Santiago del Estero, Argentina.
| | - David Díaz
- Instituto de Neurociencias de Castilla y León (INCyL), Universidad de Salamanca (USAL), Salamanca, Spain; Instituto de Investigación Biomédica de Salamanca (IBSAL), Salamanca, Spain
| | - Rosa Ferrado
- Departamento de Psicobiología, Facultad de Psicología, Universidad Nacional de Educación a Distancia (UNED), Madrid, Spain
| | - Carmelo Antonio Ávila-Zarza
- Instituto de Investigación Biomédica de Salamanca (IBSAL), Salamanca, Spain; Grupo de Estadística Aplicada, Departamento de Estadísticas, USAL, Salamanca, Spain
| | - Eduardo Weruaga
- Instituto de Neurociencias de Castilla y León (INCyL), Universidad de Salamanca (USAL), Salamanca, Spain; Instituto de Investigación Biomédica de Salamanca (IBSAL), Salamanca, Spain
| | - Emilio Ambrosio
- Departamento de Psicobiología, Facultad de Psicología, Universidad Nacional de Educación a Distancia (UNED), Madrid, Spain
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Amphetamine maintenance therapy during intermittent cocaine self-administration in rats attenuates psychomotor and dopamine sensitization and reduces addiction-like behavior. Neuropsychopharmacology 2021; 46:305-315. [PMID: 32682325 PMCID: PMC7853073 DOI: 10.1038/s41386-020-0773-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 07/07/2020] [Accepted: 07/10/2020] [Indexed: 12/19/2022]
Abstract
D-amphetamine maintenance therapy shows promise as a treatment for people with cocaine addiction. Preclinical studies using Long Access (LgA) cocaine self-administration procedures suggest D-amphetamine may act by preventing tolerance to cocaine's effects at the dopamine transporter (DAT). However, Intermittent Access (IntA) cocaine self-administration better reflects human patterns of use, is especially effective in promoting addiction-relevant behaviors, and instead of tolerance, produces psychomotor, incentive, and neural sensitization. We asked, therefore, how D-amphetamine maintenance during IntA influences cocaine use and cocaine's potency at the DAT. Male rats self-administered cocaine intermittently (5 min ON, 25 min OFF x10; 5-h/session) for 14 sessions, with or without concomitant D-amphetamine maintenance therapy during these 14 sessions (5 mg/kg/day via s.c. osmotic minipump). We then assessed responding for cocaine under a progressive ratio schedule, responding under extinction and cocaine-primed reinstatement of drug seeking. We also assessed the ability of cocaine to inhibit dopamine uptake in the nucleus accumbens core using fast scan cyclic voltammetry ex vivo. IntA cocaine self-administration produced psychomotor (locomotor) sensitization, strong motivation to take and seek cocaine, and it increased cocaine's potency at the DAT. D-amphetamine co-administration suppressed the psychomotor sensitization produced by IntA cocaine experience. After cessation of D-amphetamine treatment, the motivation to take and seek cocaine was also reduced, and sensitization of cocaine's actions at the DAT was reversed. Thus, treatment with D-amphetamine might reduce cocaine use by preventing sensitization-related changes in cocaine potency at the DAT, consistent with an incentive-sensitization view of addiction.
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Bakhti-Suroosh A, Towers EB, Lynch WJ. A buprenorphine-validated rat model of opioid use disorder optimized to study sex differences in vulnerability to relapse. Psychopharmacology (Berl) 2021; 238:1029-1046. [PMID: 33404740 PMCID: PMC7786148 DOI: 10.1007/s00213-020-05750-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Accepted: 12/08/2020] [Indexed: 12/13/2022]
Abstract
RATIONALE Opioid use disorder (OUD) is a major epidemic in the USA. Despite evidence indicating that OUD may be particularly severe for women, preclinical models have yet to establish sex as a major factor in OUD. OBJECTIVES Here, we examined sex differences in vulnerability to relapse following intermittent access fentanyl self-administration and protracted abstinence and used buprenorphine, the FDA-approved treatment for OUD, to test the validity of our model. METHODS Following acquisition of fentanyl self-administration under one of two training conditions, male and female rats were given extended, 24-h/day access to fentanyl (0.25 μg/kg/infusion, 10 days) using an intermittent access procedure. Vulnerability to relapse was assessed using an extinction/cue-induced reinstatement procedure following 14 days of abstinence; buprenorphine (0 or 3 mg/kg/day) was administered throughout abstinence. RESULTS Levels of drug-seeking were high following extended-access fentanyl self-administration and abstinence; buprenorphine markedly decreased drug-seeking supporting the validity of our relapse model. Females self-administered more fentanyl and responded at higher levels during subsequent extinction testing. Buprenorphine was effective in both sexes and eliminated sex and estrous phase differences in drug-seeking. Interestingly, the inclusion of a time-out during training had a major impact on later fentanyl self-administration in females, but not males, indicating that the initial exposure conditions can persistently impact vulnerability in females. CONCLUSIONS These findings demonstrate the utility of this rat model for determining sex and hormonal influences on the development and treatment of OUD.
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Affiliation(s)
- Anousheh Bakhti-Suroosh
- Department of Psychiatry and Neurobehavioral Sciences, University of Virginia, P.O. Box 801402, Charlottesville, VA 22904 USA
| | - Eleanor Blair Towers
- Department of Psychiatry and Neurobehavioral Sciences, University of Virginia, P.O. Box 801402, Charlottesville, VA 22904 USA
| | - Wendy J. Lynch
- Department of Psychiatry and Neurobehavioral Sciences, University of Virginia, P.O. Box 801402, Charlottesville, VA 22904 USA
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Chemogenetic Manipulation of Dopamine Neurons Dictates Cocaine Potency at Distal Dopamine Transporters. J Neurosci 2020; 40:8767-8779. [PMID: 33046544 DOI: 10.1523/jneurosci.0894-20.2020] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 09/18/2020] [Accepted: 09/27/2020] [Indexed: 12/21/2022] Open
Abstract
The reinforcing efficacy of cocaine is largely determined by its capacity to inhibit the dopamine transporter (DAT), and emerging evidence suggests that differences in cocaine potency are linked to several symptoms of cocaine use disorder. Despite this evidence, the neural processes that govern cocaine potency in vivo remain unclear. In male rats, we used chemogenetics with intra-VTA microinfusions of the agonist clozapine-n-oxide to bidirectionally modulate dopamine neurons. Using ex vivo fast scan cyclic voltammetry, pharmacological probes of the DAT, biochemical assessments of DAT membrane availability and phosphorylation, and cocaine self-administration, we tested the effects of chemogenetic manipulations on cocaine potency at distal DATs in the nucleus accumbens as well as the behavioral economics of cocaine self-administration. We discovered that chemogenetic manipulation of dopamine neurons produced rapid, bidirectional modulation of cocaine potency at DATs in the nucleus accumbens. We then provided evidence that changes in cocaine potency are associated with alterations in DAT affinity for cocaine and demonstrated that this change in affinity coincides with DAT conformation biases and changes in DAT phosphorylation state. Finally, we showed that chemogenetic manipulation of dopamine neurons alters cocaine consumption in a manner consistent with changes in cocaine potency at distal DATs. Based on the spatial and temporal constraints inherent to our experimental design, we posit that changes in cocaine potency are driven by alterations in dopamine neuron activity. When considered together, these observations provide a novel mechanism through which GPCRs regulate cocaine's pharmacological and behavioral effects.SIGNIFICANCE STATEMENT Differences in the pharmacological effects of cocaine are believed to influence the development and progression of cocaine use disorder. However, the biological and physiological processes that determine sensitivity to cocaine remain unclear. In this work, we use a combination of chemogenetics, fast scan cyclic voltammetry, pharmacology, biochemistry, and cocaine self-administration with economic demand analysis to demonstrate a novel mechanism by which cocaine potency is determined in vivo These studies identify a novel process by which the pharmacodynamics of cocaine are derived in vivo, and thus this work has widespread implications for understanding the mechanisms that regulate cocaine consumption across stages of addiction.
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Intermittent but not continuous access to cocaine produces individual variability in addiction susceptibility in rats. Psychopharmacology (Berl) 2020; 237:2929-2941. [PMID: 32556402 PMCID: PMC7529862 DOI: 10.1007/s00213-020-05581-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Accepted: 06/08/2020] [Indexed: 10/24/2022]
Abstract
Drug addiction is a chronic disease defined by a complex set of characteristics, including loss of control over drug intake and persistent drug craving, which primarily affects a small percentage of people who try drugs. Although many models have been developed to study individual aspects of drug use, there is great translational value in having an animal model that encompasses multiple aspects of the human disease, including the variation in severity observed in humans. Here, we describe an intermittent access model of cocaine self-administration that produces a subset of rats that display many of the core features of addiction, including escalation of drug intake, a binge-like pattern of drug use, robust locomotor sensitization, and high levels of drug-seeking during cue-induced reinstatement. This group is compared with rats that have the same drug history but do not develop this pattern of drug-taking and drug-seeking, as well as rats that undergo a traditional continuous access paradigm. Finally, we observe that high levels of cocaine consumption produce long-term changes in intracellular calcium signaling in the dorsomedial striatum.
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Interruption of continuous opioid exposure exacerbates drug-evoked adaptations in the mesolimbic dopamine system. Neuropsychopharmacology 2020; 45:1781-1792. [PMID: 32079024 PMCID: PMC7608117 DOI: 10.1038/s41386-020-0643-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 02/10/2020] [Accepted: 02/13/2020] [Indexed: 12/14/2022]
Abstract
Drug-evoked adaptations in the mesolimbic dopamine system are postulated to drive opioid abuse and addiction. These adaptations vary in magnitude and direction following different patterns of opioid exposure, but few studies have systematically manipulated the pattern of opioid administration while measuring neurobiological and behavioral impact. We exposed male and female mice to morphine for one week, with administration patterns that were either intermittent (daily injections) or continuous (osmotic minipump infusion). We then interrupted continuous morphine exposure with either naloxone-precipitated or spontaneous withdrawal. Continuous morphine exposure caused tolerance to the psychomotor-activating effects of morphine, whereas both intermittent and interrupted morphine exposure caused long-lasting psychomotor sensitization. Given links between locomotor sensitization and mesolimbic dopamine signaling, we used fiber photometry and a genetically encoded dopamine sensor to conduct longitudinal measurements of dopamine dynamics in the nucleus accumbens. Locomotor sensitization caused by interrupted morphine exposure was accompanied by enhanced dopamine signaling in the nucleus accumbens. To further assess downstream consequences on striatal gene expression, we used next-generation RNA sequencing to perform genome-wide transcriptional profiling in the nucleus accumbens and dorsal striatum. The interruption of continuous morphine exposure exacerbated drug-evoked transcriptional changes in both nucleus accumbens and dorsal striatum, dramatically increasing differential gene expression and engaging unique signaling pathways. Our study indicates that opioid-evoked adaptations in brain function and behavior are critically dependent on the pattern of drug administration, and exacerbated by interruption of continuous exposure. Maintaining continuity of chronic opioid administration may, therefore, represent a strategy to minimize iatrogenic effects on brain reward circuits.
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Algallal H, Allain F, Ndiaye NA, Samaha A. Sex differences in cocaine self-administration behaviour under long access versus intermittent access conditions. Addict Biol 2020; 25:e12809. [PMID: 31373148 DOI: 10.1111/adb.12809] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 06/05/2019] [Accepted: 06/12/2019] [Indexed: 11/27/2022]
Abstract
Studies in humans suggest that women progress more rapidly from initial cocaine use to addiction. Similarly, female rats can show more incentive motivation for cocaine than male rats do. Most preclinical studies on this issue have used self-administration procedures that provide continuous cocaine access during each session ("long-access" or LgA and "short-access"). However, intermittent access (IntA) cocaine self-administration better models the intermittency of human cocaine use. Here, we compared cocaine use in female and male rats that received ten, daily 6-hour LgA or IntA sessions. Cocaine intake was greatest under LgA, and female LgA rats escalated their intake. Only IntA rats (both sexes) developed locomotor sensitization to self-administered cocaine, and sensitization was greatest in females. Five and 25 days after the last self-administration session, we quantified responding for cocaine (0.083-0.75 mg/kg/infusion) under a progressive ratio (PR) schedule, a measure of motivation for drug. Across conditions, females earned more cocaine infusions than males under the PR schedule. Across sexes, IntA rats earned more infusions than LgA rats, even though IntA rats had previously taken much less cocaine. Cumulative cocaine intake significantly predicted responding for cocaine under the PR schedule in male LgA rats only. In IntA rats, the extent of locomotor sensitization significantly predicted responding under the PR schedule. Thus, LgA might be appropriate to study sex differences in cocaine intake, whereas IntA might be best suited to study sex differences in sensitization-related neuroadaptations involved in cocaine addiction. This has implications for modelling distinct features of cocaine addiction in preclinical studies.
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Affiliation(s)
- Hajer Algallal
- Department of Biomedical Sciences, Faculty of MedicineUniversité de Montréal Montreal Quebec Canada
| | - Florence Allain
- Department of Pharmacology and Physiology, Faculty of MedicineUniversité de Montréal Montreal Quebec Canada
| | - Ndeye Aissatou Ndiaye
- Department of Neurosciences, Faculty of MedicineUniversité de Montréal Montreal Quebec Canada
| | - Anne‐Noël Samaha
- Department of Pharmacology and Physiology, Faculty of MedicineUniversité de Montréal Montreal Quebec Canada
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Mimicking Human Drug Consumption Patterns in Rat Engages Corticostriatal Circuitry. Neuroscience 2020; 442:311-313. [PMID: 32682655 DOI: 10.1016/j.neuroscience.2020.06.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2020] [Accepted: 06/08/2020] [Indexed: 12/19/2022]
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Intermittent access cocaine self-administration produces psychomotor sensitization: effects of withdrawal, sex and cross-sensitization. Psychopharmacology (Berl) 2020; 237:1795-1812. [PMID: 32206828 PMCID: PMC7244391 DOI: 10.1007/s00213-020-05500-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 02/28/2020] [Indexed: 02/05/2023]
Abstract
RATIONALE With repeated administration, the psychomotor activating effects of drugs such as cocaine or amphetamine can change in very different ways-showing sensitization or tolerance-depending on whether they are administered more or less intermittently. This behavioral plasticity is thought to reflect, at least in part, changes in dopamine (DA) neurotransmission, and therefore, may provide insights into the development of substance use disorders. Indeed, the most widely used preclinical model of cocaine addiction, which involves Long Access (LgA) self-administration procedures, is reported to produce tolerance to cocaine's psychomotor activating effects and effects on DA activity. In contrast, Intermittent Access (IntA) cocaine self-administration is more effective than LgA in producing addiction-like behavior, but sensitizes DA neurotransmission. There is, however, very little information concerning the effects of IntA experience on the psychomotor activating effects of cocaine. OBJECTIVE The objective of this study was to determine whether IntA experience produces psychomotor sensitization with similar characteristics to that produced by the intermittent, noncontingent administration of cocaine. RESULTS IntA to cocaine did indeed produce psychomotor sensitization that (1) was greater after a long (30 days) vs. short (1 day) period of withdrawal, (2) was greater in females than males, and (3) resulted in cross-sensitization to another psychomotor stimulant drug, amphetamine. CONCLUSION The tolerance sometimes associated with LgA cocaine self-administration has been cited in support of the idea that, in addiction, drug-seeking and drug-taking is motivated to overcome a DA deficiency and associated anhedonia. In contrast, the neurobehavioral sensitization associated with IntA cocaine self-administration favors an incentive-sensitization view.
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Allain F, Samaha AN. [Cocaine peaks and troughs. Modeling pathological drug use in rats]. Med Sci (Paris) 2020; 36:212-215. [PMID: 32228836 DOI: 10.1051/medsci/2020034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Florence Allain
- Département de pharmacologie et de physiologie, Groupe de recherche sur le système nerveux central, Faculté de médecine, Université de Montréal, Montréal, QC, H3C 3J7, Canada
| | - Anne-Noël Samaha
- Département de pharmacologie et de physiologie, Groupe de recherche sur le système nerveux central, Faculté de médecine, Université de Montréal, Montréal, QC, H3C 3J7, Canada
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Phasic Dopamine Release Magnitude Tracks Individual Differences in Sensitization of Locomotor Response following a History of Nicotine Exposure. Sci Rep 2020; 10:173. [PMID: 31932634 PMCID: PMC6957501 DOI: 10.1038/s41598-019-56884-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Accepted: 12/06/2019] [Indexed: 02/04/2023] Open
Abstract
Smoking remains the primary cause of preventable death in the United States and smoking related illness costs more than $300 billion annually. Nicotine (the primary reinforcer in cigarettes) causes changes in behavior and neurochemistry that lead to increased probability of relapse. Given the role of mesolimbic dopamine projections in motivation, substance use disorder, and drug relapse, we examined the effect of repeated nicotine on rapid dopamine signals in the nucleus accumbens (NAc) of rats. Adult, male Sprague-Dawley rats were exposed to nicotine (0.2 or 0.4 mg/kg, subcutaneous) once daily for 7 days. On day 8, dopamine release and uptake dynamics, and their modulation by nicotinic receptor agonists and antagonists, were assessed using fast scan cyclic voltammetry in the NAc core. Nicotine exposure decreased electrically-stimulated dopamine release across a range of stimulation frequencies and decreased α6β2-containing nicotinic receptor control over dopamine release. Additionally, nicotine locomotor sensitization correlated with accumbal dopamine modulation by nicotine and mecamylamine. Taken together, our study suggests that repeated exposure to nicotine blunts dopamine release in the NAc core through changes in α6β2 modulation of dopamine release and individual differences in the sensitivity to this outcome may predict variation in behavioral models of vulnerability to substance use disorder.
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Minogianis EA, Servonnet A, Filion MP, Samaha AN. Role of the orbitofrontal cortex and the dorsal striatum in incentive motivation for cocaine. Behav Brain Res 2019; 372:112026. [PMID: 31195036 DOI: 10.1016/j.bbr.2019.112026] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Revised: 05/30/2019] [Accepted: 06/08/2019] [Indexed: 12/11/2022]
Abstract
Drug addiction involves increased incentive motivation for drug. Intermittent access to cocaine (IntA; 5-6 minutes ON, 25-26 minutes OFF, for 5-6 hours/session) enhances motivation to take the drug. The orbitofrontal cortex (OFC) and the dorsal striatum (DS) are part of a corticolimbic circuit that encodes incentive value and regulates reward-directed behaviour. We predicted that inactivation of the OFC, DS or both suppresses incentive motivation for cocaine after IntA experience. Male Wistar rats had IntA to cocaine (0.25 mg/kg/infusion) for 10 sessions. The rats developed a 'loading' pattern of intake, taking most of their cocaine in the first minute of each drug-available period. They also developed psychomotor sensitization to self-administered cocaine. We then measured incentive motivation for cocaine using a progressive ratio schedule of reinforcement (PR). Before some PR sessions, rats received microinfusions of a baclofen/muscimol cocktail (0.3 and 0.03 nmol/hemisphere, respectively, or saline) to temporarily inactivate the OFC or DS, or to disconnect the two regions. None of these treatments changed spontaneous locomotion in cocaine-naïve rats. However, both baclofen/muscimol and saline infusions influenced cocaine self-administration behaviour. Infusing baclofen/muscimol or saline into the OFC or into the OFC and contralateral DS decreased responding for cocaine under PR, with baclofen/muscimol and saline having similar effects, except that only OFC-DS disconnection with baclofen/muscimol slowed the pace of cocaine intake. Baclofen/muscimol or saline into the DS also reduced responding for cocaine under PR, but baclofen/muscimol was more effective. We conclude that neuronal activity in the OFC and DS might regulate incentive motivation for cocaine.
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Affiliation(s)
- Ellie-Anna Minogianis
- Department of Pharmacology and Physiology, Faculty of Medicine, Université de Montréal, Canada
| | - Alice Servonnet
- Department of Neuroscience, Faculty of Medicine, Université de Montréal, Canada
| | - Marie-Pier Filion
- Department of Pharmacology and Physiology, Faculty of Medicine, Université de Montréal, Canada
| | - Anne-Noël Samaha
- Department of Pharmacology and Physiology, Faculty of Medicine, Université de Montréal, Canada; Central Nervous System Research Group (GRSNC), Faculty of Medicine, Université de Montréal, Canada.
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Kawa AB, Valenta AC, Kennedy RT, Robinson TE. Incentive and dopamine sensitization produced by intermittent but not long access cocaine self-administration. Eur J Neurosci 2019; 50:2663-2682. [PMID: 30968487 PMCID: PMC6742545 DOI: 10.1111/ejn.14418] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 03/21/2019] [Accepted: 04/03/2019] [Indexed: 12/31/2022]
Abstract
The temporal pattern of drug use (pharmacokinetics) has a profound effect on the ability of self-administered cocaine to produce addiction-like behavior in rodents, and to change the brain. To further address this issue, we compared the effects of long access (LgA) cocaine self-administration, which is widely used to model the transition to addiction, with intermittent access (IntA), which is thought to better reflect the pattern of drug use in humans, on the ability of a single, self-administered injection of cocaine to increase dopamine (DA) overflow in the core of the nucleus accumbens (using in vivo microdialysis), and to produce addiction-like behavior. IntA experience was more effective than LgA in producing addiction-like behavior-a drug experience-dependent increase in motivation for cocaine assessed using behavioral economic procedures, and cue-induced reinstatement-despite much less total drug consumption. There were no group differences in basal levels of DA in dialysate [DA], but a single self-administered IV injection of cocaine increased [DA] in the core of the nucleus accumbens to a greater extent in rats with prior IntA experience than those with LgA or limited access experience, and the latter two groups did not differ. Furthermore, high motivation for cocaine was associated with a high [DA] response. Thus, IntA, but not LgA, produced both incentive and DA sensitization. This is consistent with the notion that a hyper-responsive dopaminergic system may contribute to the transition from casual patterns of drug use to the problematic patterns that define addiction.
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Affiliation(s)
- Alex B. Kawa
- Department of Psychology (Biopsychology Program), University of Michigan, Ann Arbor, MI, USA
| | - Alec C. Valenta
- Department of Chemistry, University of Michigan, Ann Arbor, MI, USA
| | | | - Terry E. Robinson
- Department of Psychology (Biopsychology Program), University of Michigan, Ann Arbor, MI, USA
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Allain F, Samaha A. Revisiting long-access versus short-access cocaine self-administration in rats: intermittent intake promotes addiction symptoms independent of session length. Addict Biol 2019; 24:641-651. [PMID: 29920865 DOI: 10.1111/adb.12629] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Revised: 04/06/2018] [Accepted: 04/11/2018] [Indexed: 12/19/2022]
Abstract
In rats, continuous cocaine access during long self-administration sessions (6 versus 1-2 hours) promotes the development of behavioral symptoms of addiction. This has led to the assumption that taking large amounts of drug during extended daily bouts is necessary to develop an addiction phenotype. Recent work shows that within-session intermittent access (IntA) to cocaine produces much less drug intake than continuous-access procedures (i.e. long-access sessions) but evokes addiction symptoms more effectively. IntA-sessions are also long, typically lasting 6 hours. It is not known whether IntA-sessions must be extended to promote addiction-relevant changes in drug use over time. Here, we determined the influence of IntA-session length on patterns of cocaine use relevant to addiction. Two groups of male Wistar rats self-administered cocaine (0.25 mg/kg/injection, injected over 5 seconds) during 18 daily IntA-sessions. One group had long 6-hour sessions (Long-IntA), the other group had shorter, 2-hour sessions (Short-IntA). Only Long-IntA rats escalated their cocaine intake over sessions, but both groups developed a burst-like pattern of drug use over time and similar levels of psychomotor sensitization. The two groups also showed robust and similar levels of both responding for cocaine under a progressive ratio schedule of reinforcement and cocaine-induced reinstatement of extinguished drug-seeking behavior. In summary, long IntA-sessions lead to greater cocaine intake than shorter IntA-sessions, but the two conditions are equally effective in evoking the patterns of drug-taking and drug-seeking that define addiction. This suggests that chronic intermittent cocaine use, even during short daily bouts, is sufficient to promote addiction symptoms.
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Affiliation(s)
- Florence Allain
- Department of Pharmacology and Physiology, Faculty of MedicineUniversité de Montréal Canada
| | - Anne‐Noël Samaha
- Department of Pharmacology and Physiology, Faculty of MedicineUniversité de Montréal Canada
- CNS Research Group, Faculty of MedicineUniversité de Montréal Canada
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40
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Incubation of Cocaine Craving After Intermittent-Access Self-administration: Sex Differences and Estrous Cycle. Biol Psychiatry 2019; 85:915-924. [PMID: 30846301 PMCID: PMC6534474 DOI: 10.1016/j.biopsych.2019.01.015] [Citation(s) in RCA: 86] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 01/17/2019] [Accepted: 01/17/2019] [Indexed: 11/20/2022]
Abstract
BACKGROUND Studies using continuous-access drug self-administration showed that cocaine seeking increases during abstinence (incubation of cocaine craving). Recently, studies using intermittent-access self-administration showed increased motivation to self-administer and seek cocaine. We examined whether intermittent cocaine self-administration would potentiate incubation of craving in male and female rats and examined the estrous cycle's role in this incubation. METHODS In experiment 1, male and female rats self-administered cocaine either continuously (8 hours/day) or intermittently (5 minutes ON, 25 minutes OFF × 16) for 12 days, followed by relapse tests after 2 or 29 days. In experiments 2 and 3, female rats self-administered cocaine intermittently for six, 12, or 18 sessions. In experiment 4, female rats self-administered cocaine continuously followed by relapse tests after 2 or 29 days. In experiments 3 and 4, the estrous cycle was measured using a vaginal smear test. RESULTS Incubation of cocaine craving was observed in both sexes after either intermittent or continuous drug self-administration. Independent of access condition and abstinence day, cocaine seeking was higher in female rats than in male rats. In both sexes, cocaine seeking on both abstinence days was higher after intermittent drug access than after continuous drug access. In female rats, incubation of craving after either intermittent or continuous drug access was significantly higher during estrus than during non-estrus; for intermittent drug access, this effect was independent of the training duration. CONCLUSIONS In both sexes, intermittent cocaine access caused time-independent increases in drug seeking during abstinence. In female rats, the time-dependent increase in drug seeking (incubation) is critically dependent on the estrous cycle phase.
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James MH, Stopper CM, Zimmer BA, Koll NE, Bowrey HE, Aston-Jones G. Increased Number and Activity of a Lateral Subpopulation of Hypothalamic Orexin/Hypocretin Neurons Underlies the Expression of an Addicted State in Rats. Biol Psychiatry 2019; 85:925-935. [PMID: 30219208 PMCID: PMC7528037 DOI: 10.1016/j.biopsych.2018.07.022] [Citation(s) in RCA: 110] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Revised: 07/09/2018] [Accepted: 07/20/2018] [Indexed: 10/28/2022]
Abstract
BACKGROUND The orexin (hypocretin) system is important for reward-driven motivation but has not been implicated in the expression of a multiphenotype addicted state. METHODS Rats were assessed for economic demand for cocaine before and after 14 days of short access, long access, or intermittent access (IntA) to cocaine. Rats were also assessed for a number of other DSM-5-relevant addiction criteria following differential access conditions. Orexin system function was assessed by quantification of numbers and activity of orexin cells, pharmacological blockade of the orexin-1 receptor, and subregion-specific knockdown of orexin cell populations. RESULTS IntA produced a cluster of addiction-like behaviors that closely recapitulate key diagnostic criteria for addiction to a greater extent than long access or short access. IntA was accompanied by an increase in number and activity of orexin-expressing neurons within the lateral hypothalamic subregion. This increase in orexin cell number and activity persisted during protracted withdrawal from cocaine for at least 150 days and was accompanied by enhanced incubation of craving in the same rats. Selective knockdown of lateral hypothalamic orexin neurons reduced motivation for cocaine, and orexin-1 receptor signaling played a larger role in drug seeking after IntA. CONCLUSIONS We provide the first evidence that lateral hypothalamic orexin system function extends beyond general reward seeking to play a critical role in expression of a multiphenotype addiction-like state. Thus, the orexin system is a potential novel target for pharmacotherapies designed to treat cocaine addiction. In addition, these data point to the IntA model as a preferred approach to modeling addiction-like behavior in rats.
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42
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The transition to cocaine addiction: the importance of pharmacokinetics for preclinical models. Psychopharmacology (Berl) 2019; 236:1145-1157. [PMID: 30820634 PMCID: PMC6592776 DOI: 10.1007/s00213-019-5164-0] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Accepted: 01/03/2019] [Indexed: 01/10/2023]
Abstract
A key question in addiction research concerns how, in some individuals, initial recreational or casual patterns of drug use may change brain and psychological function in ways that promote a transition to the problematic patterns of use that define substance use disorders (addiction). In preclinical studies, this is modeled using self-administration procedures. However, most cocaine self-administration procedures produce continuously high brain concentrations of drug, whereas in people, bouts of use are thought to be more intermittent. Here, we ask whether such temporal pharmacokinetic factors matter, by comparing and contrasting the neuropsychological consequences of intermittent vs. long access cocaine self-administration experience. It turns out, the temporal pattern of cocaine use has profound effects on a number of outcomes. First, despite much less total drug consumption, intermittent access to cocaine is more effective in producing addiction-like behavior. Second, intermittent and long access cocaine self-administration change the brain in very different ways to influence motivated behavior. We argue that intermittent access self-administration procedures might be better suited than traditional self-administration procedures for isolating drug-induced changes in neuropsychological function that contribute to the transition to cocaine addiction.
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43
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Taksande BG, Khade SD, Aglawe MM, Gujar S, Chopde CT, Kotagale NR. Agmatine Inhibits Behavioral Sensitization to Ethanol Through Imidazoline Receptors. Alcohol Clin Exp Res 2019; 43:747-757. [DOI: 10.1111/acer.13972] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Accepted: 01/29/2019] [Indexed: 12/13/2022]
Affiliation(s)
- Brijesh G. Taksande
- Department of Pharmacology Division of Neuroscience Shrimati Kishoritai Bhoyar College of Pharmacy Nagpur India
| | - Supriya D. Khade
- Department of Pharmacology Division of Neuroscience Shrimati Kishoritai Bhoyar College of Pharmacy Nagpur India
| | - Manish M. Aglawe
- Department of Pharmacology Division of Neuroscience Shrimati Kishoritai Bhoyar College of Pharmacy Nagpur India
| | - Shreyans Gujar
- Department of Pharmacology Division of Neuroscience Shrimati Kishoritai Bhoyar College of Pharmacy Nagpur India
| | - Chandrabhan T. Chopde
- Department of Pharmacology Division of Neuroscience Shrimati Kishoritai Bhoyar College of Pharmacy Nagpur India
| | - Nandkishor R. Kotagale
- Department of Pharmacology Division of Neuroscience Shrimati Kishoritai Bhoyar College of Pharmacy Nagpur India
- Government Colleges of Pharmacy Amravati India
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López AJ, Siciliano CA, Calipari ES. Activity-Dependent Epigenetic Remodeling in Cocaine Use Disorder. Handb Exp Pharmacol 2019; 258:231-263. [PMID: 31628597 DOI: 10.1007/164_2019_257] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Substance use disorder (SUD) is a behavioral disorder characterized by cycles of abstinence, drug seeking, and relapse. SUD is characterized by aberrant learning processes which develop after repeated exposure to drugs of abuse. At the core of this phenotype is the persistence of symptoms, such as craving and relapse to drug seeking, long after the cessation of drug use. The neural basis of these behavioral changes has been linked to dysfunction in neural circuits across the brain; however, the molecular drivers that allow for these changes to persist beyond the lifespan of any individual protein remain opaque. Epigenetic adaptations - where DNA is modified to increase or decrease the probability of gene expression at key genes - have been identified as a mechanism underlying the long-lasting nature of drug-seeking behavior. Thus, to understand SUD, it is critical to define the interplay between neuronal activation and longer-term changes in transcription and epigenetic remodeling and define their role in addictive behaviors. In this review, we discuss the current understanding of drug-induced changes to circuit function, recent discoveries in epigenetic mechanisms that mediate these changes, and, ultimately, how these adaptations drive the persistent nature of relapse, with emphasis on adaptations in models of cocaine use disorder. Understanding the complex interplay between epigenetic gene regulation and circuit activity will be critical in elucidating the neural mechanisms underlying SUD. This, with the advent of novel genetic-based techniques, will allow for the generation of novel therapeutic avenues to improve treatment outcomes in SUD.
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Affiliation(s)
- Alberto J López
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN, USA.,Vanderbilt Center for Addiction Research, Vanderbilt University School of Medicine, Nashville, TN, USA.,Vanderbilt Brain Institute, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Cody A Siciliano
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN, USA.,Vanderbilt Center for Addiction Research, Vanderbilt University School of Medicine, Nashville, TN, USA.,Vanderbilt Brain Institute, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Erin S Calipari
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN, USA. .,Vanderbilt Center for Addiction Research, Vanderbilt University School of Medicine, Nashville, TN, USA. .,Vanderbilt Brain Institute, Vanderbilt University School of Medicine, Nashville, TN, USA. .,Department of Molecular Physiology and Biophysics, Vanderbilt Institute for Infection, Immunology, and Infection, Vanderbilt University School of Medicine, Nashville, TN, USA. .,Department of Psychiatry and Behavioral Sciences, Vanderbilt Institute for Infection, Immunology, and Infection, Vanderbilt University School of Medicine, Nashville, TN, USA.
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45
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Highgate Q, Schenk S. Comparison of the effects of abstinence on MDMA and cocaine self-administration in rats. Psychopharmacology (Berl) 2018; 235:3233-3241. [PMID: 30209532 DOI: 10.1007/s00213-018-5026-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2018] [Accepted: 09/04/2018] [Indexed: 12/16/2022]
Abstract
RATIONALE 3,4-Methylenedioxymethamphetamine (MDMA) preferentially increases synaptic serotonin (5HT). This response was attenuated following repeated exposure but there was recovery as a result of abstinence. Effects of abstinence on self-administration of many drugs have been documented but the impact on MDMA self-administration is unknown. OBJECTIVE This study compared the effects of abstinence on MDMA and cocaine self-administration. METHODS Six-hour daily MDMA or cocaine sessions were conducted until a total of 350 mg/kg had been self-administered. Following this, rats were randomly assigned to either a 0- or 14-day abstinence group. Self-administration testing then continued for an additional 7 days. RESULTS The latency to self-administer 350 mg/kg was shorter for rats that self-administered cocaine. The temporal distribution of responding within each test session also differed; MDMA self-administration was high during the first hour of each session, and decreased during subsequent hours, whereas cocaine self-administration was evenly distributed throughout each hour of the session. Abstinence decreased MDMA but not cocaine self-administration. CONCLUSIONS The selective reduction of MDMA self-administration following abstinence is consistent with the idea that MDMA-stimulated 5-HT release is inhibitory to MDMA self-administration.
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Affiliation(s)
- Quenten Highgate
- School of Psychology, Victoria University of Wellington, Wellington, 6011, New Zealand
| | - Susan Schenk
- School of Psychology, Victoria University of Wellington, Wellington, 6011, New Zealand.
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46
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Lespine LF, Tirelli E. Evidence for a long-term protection of wheel-running exercise against cocaine psychomotor sensitization in adolescent but not in adult mice. Behav Brain Res 2018; 349:63-72. [DOI: 10.1016/j.bbr.2018.04.054] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 04/30/2018] [Accepted: 04/30/2018] [Indexed: 12/16/2022]
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47
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Heterogeneous dopamine signals support distinct features of motivated actions: implications for learning and addiction. ACTA ACUST UNITED AC 2018; 25:416-424. [PMID: 30115763 PMCID: PMC6097772 DOI: 10.1101/lm.047019.117] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Accepted: 06/15/2018] [Indexed: 01/05/2023]
Abstract
Despite decades of research, investigations into effective neural and pharmacological therapies for many drugs of abuse, such as cocaine, have produced no FDA-approved approaches. This difficulty derives from the complexity of substance use disorders, which encompass a variety of behavioral, psychological, and neural circuit-based changes that occur as a result of repeated experience with the drug. Dopamine signaling has been demonstrated to play a key role in several aspects of drug abuse—from mediating its reinforcing properties and drug-seeking to triggering relapse—while also mediating a number of important aspects of normal (nondrug related) motivated behaviors and actions. Real-time recording methods such as in vivo voltammetry, electrophysiology, and calcium imaging demonstrate that the signaling properties of dopamine for motivationally relevant stimuli are highly dynamic and spatiotemporally circumscribed within afferent target regions. In this review, we identify the origins and functional consequences of heterogeneous dopamine release in the limbic system, and how these properties are persistently altered in the drug-experienced brain. We propose that these spatiotemporally parallel dopaminergic signals are simultaneously available to the animal, but that these circuits are impaired following prolonged drug experience by disrupting the location and content of dopamine signals in afferent target regions. These findings are discussed in the context of relapse and pathways to discovering new treatments for addiction disorders.
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48
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Hypocretin receptor 1 involvement in cocaine-associated behavior: Therapeutic potential and novel mechanistic insights. Brain Res 2018; 1731:145894. [PMID: 30071195 DOI: 10.1016/j.brainres.2018.07.027] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Revised: 07/05/2018] [Accepted: 07/12/2018] [Indexed: 12/28/2022]
Abstract
Since its discovery in 1998, the hypocretin/orexin system has been identified as a critical modulator of behavior. Through interactions with dopamine neurons of the ventral tegmental area, this system is poised to regulate motivation for drug rewards by impacting dopamine neurotransmission in target structures including the nucleus accumbens. Across numerous experiments, we and others have identified a critical influence of hypocretin receptor 1 in mediating the behavioral and physiological effects of cocaine which positions this receptor as a potential target for the treatment of cocaine addiction. Here we discuss evidence for hypocretin receptor 1 involvement in driving cocaine-associated behavior and how hypocretin receptor 1 in the ventral tegmental area are critical for supporting dopamine neuron activity and dopamine neurotransmission. We then present new data supporting the novel hypothesis that in addition to exerting acute actions on dopamine systems, pharmacological hypocretin manipulations also produce lasting adaptations to dopamine terminals that impact sensitivity to cocaine, and ultimately, future behavior.
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49
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Zhu R, Bu Q, Fu D, Shao X, Jiang L, Guo W, Chen B, Liu B, Hu Z, Tian J, Zhao Y, Cen X. Toll-like receptor 3 modulates the behavioral effects of cocaine in mice. J Neuroinflammation 2018; 15:93. [PMID: 29571298 PMCID: PMC5865345 DOI: 10.1186/s12974-018-1130-8] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Accepted: 03/13/2018] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND The nucleus accumbens in the midbrain dopamine limbic system plays a key role in cocaine addiction. Toll-like receptors (TLRs) are important pattern-recognition receptors (PPRs) in the innate immune system that are also involved in drug dependence; however, the detailed mechanism is largely unknown. METHODS The present study was designed to investigate the potential role of TLR3 in cocaine addiction. Cocaine-induced conditioned place preference (CPP), locomotor activity, and self-administration were used to determine the effects of TLR3 in the rewarding properties of cocaine. Lentivirus-mediated re-expression of Tlr3 (LV-TLR3) was applied to determine if restoration of TLR3 expression in the NAc is sufficient to restore the cocaine effect in TLR3-/- mice. The protein levels of phospho-NF-κB p65, IKKβ, and p-IκBα both in the cytoplasm and nucleus of cocaine-induced CPP mice were detected by Western blot. RESULTS We showed that both TLR3 deficiency and intra-NAc injection of TLR3 inhibitors significantly attenuated cocaine-induced CPP, locomotor activity, and self-administration in mice. Importantly, the TLR3-/- mice that received intra-NAc injection of LV-TLR3 displayed significant increases in cocaine-induced CPP and locomotor activity. Finally, we found that TLR3 inhibitor reverted cocaine-induced upregulation of phospho-NF-κB p65, IKKβ, and p-IκBα. CONCLUSIONS Taken together, our results describe that TLR3 modulates cocaine-induced behaviors and provide further evidence supporting a role for central pro-inflammatory immune signaling in drug reward. We propose that TLR3 blockade could be a novel approach to treat cocaine addiction.
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Affiliation(s)
- Ruiming Zhu
- National Chengdu Center for Safety Evaluation of Drugs, State Key Lab of Biotherapy/Collaborative Innovation Center of Biotherapy, West China Hospital, West China Medical School, Sichuan University, #28 Gaopeng Street, High Technological Development Zone, Chengdu, 610041, China
| | - Qian Bu
- National Chengdu Center for Safety Evaluation of Drugs, State Key Lab of Biotherapy/Collaborative Innovation Center of Biotherapy, West China Hospital, West China Medical School, Sichuan University, #28 Gaopeng Street, High Technological Development Zone, Chengdu, 610041, China.,Healthy Food Evaluation Research Center, Department of Food Science and Technology, College of Light Industry, Textile and Food Engineering, Sichuan University, Chengdu, 610065, China
| | - Dengqi Fu
- National Chengdu Center for Safety Evaluation of Drugs, State Key Lab of Biotherapy/Collaborative Innovation Center of Biotherapy, West China Hospital, West China Medical School, Sichuan University, #28 Gaopeng Street, High Technological Development Zone, Chengdu, 610041, China
| | - Xue Shao
- National Chengdu Center for Safety Evaluation of Drugs, State Key Lab of Biotherapy/Collaborative Innovation Center of Biotherapy, West China Hospital, West China Medical School, Sichuan University, #28 Gaopeng Street, High Technological Development Zone, Chengdu, 610041, China
| | - Linhong Jiang
- National Chengdu Center for Safety Evaluation of Drugs, State Key Lab of Biotherapy/Collaborative Innovation Center of Biotherapy, West China Hospital, West China Medical School, Sichuan University, #28 Gaopeng Street, High Technological Development Zone, Chengdu, 610041, China
| | - Wei Guo
- National Chengdu Center for Safety Evaluation of Drugs, State Key Lab of Biotherapy/Collaborative Innovation Center of Biotherapy, West China Hospital, West China Medical School, Sichuan University, #28 Gaopeng Street, High Technological Development Zone, Chengdu, 610041, China.,School of Pharmacy, Key Laboratory of Molecular Pharmacology and Drug Evaluation (Yantai University), Ministry of Education, Collaborative Innovation Center of Advanced Drug Delivery System and Biotech Drugs in Universities of Shandong, Yantai University, Yantai, 264005, China
| | - Bo Chen
- National Chengdu Center for Safety Evaluation of Drugs, State Key Lab of Biotherapy/Collaborative Innovation Center of Biotherapy, West China Hospital, West China Medical School, Sichuan University, #28 Gaopeng Street, High Technological Development Zone, Chengdu, 610041, China
| | - Bin Liu
- National Chengdu Center for Safety Evaluation of Drugs, State Key Lab of Biotherapy/Collaborative Innovation Center of Biotherapy, West China Hospital, West China Medical School, Sichuan University, #28 Gaopeng Street, High Technological Development Zone, Chengdu, 610041, China
| | - Zhengtao Hu
- National Chengdu Center for Safety Evaluation of Drugs, State Key Lab of Biotherapy/Collaborative Innovation Center of Biotherapy, West China Hospital, West China Medical School, Sichuan University, #28 Gaopeng Street, High Technological Development Zone, Chengdu, 610041, China
| | - Jingwei Tian
- School of Pharmacy, Key Laboratory of Molecular Pharmacology and Drug Evaluation (Yantai University), Ministry of Education, Collaborative Innovation Center of Advanced Drug Delivery System and Biotech Drugs in Universities of Shandong, Yantai University, Yantai, 264005, China
| | - Yinglan Zhao
- National Chengdu Center for Safety Evaluation of Drugs, State Key Lab of Biotherapy/Collaborative Innovation Center of Biotherapy, West China Hospital, West China Medical School, Sichuan University, #28 Gaopeng Street, High Technological Development Zone, Chengdu, 610041, China
| | - Xiaobo Cen
- National Chengdu Center for Safety Evaluation of Drugs, State Key Lab of Biotherapy/Collaborative Innovation Center of Biotherapy, West China Hospital, West China Medical School, Sichuan University, #28 Gaopeng Street, High Technological Development Zone, Chengdu, 610041, China.
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50
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Granulocyte-colony stimulating factor controls neural and behavioral plasticity in response to cocaine. Nat Commun 2018; 9:9. [PMID: 29339724 PMCID: PMC5770429 DOI: 10.1038/s41467-017-01881-x] [Citation(s) in RCA: 129] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 10/20/2017] [Indexed: 01/27/2023] Open
Abstract
Cocaine addiction is characterized by dysfunction in reward-related brain circuits, leading to maladaptive motivation to seek and take the drug. There are currently no clinically available pharmacotherapies to treat cocaine addiction. Through a broad screen of innate immune mediators, we identify granulocyte-colony stimulating factor (G-CSF) as a potent mediator of cocaine-induced adaptations. Here we report that G-CSF potentiates cocaine-induced increases in neural activity in the nucleus accumbens (NAc) and prefrontal cortex. In addition, G-CSF injections potentiate cocaine place preference and enhance motivation to self-administer cocaine, while not affecting responses to natural rewards. Infusion of G-CSF neutralizing antibody into NAc blocks the ability of G-CSF to modulate cocaine's behavioral effects, providing a direct link between central G-CSF action in NAc and cocaine reward. These results demonstrate that manipulating G-CSF is sufficient to alter the motivation for cocaine, but not natural rewards, providing a pharmacotherapeutic avenue to manipulate addictive behaviors without abuse potential.
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