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Gobira PH, Joca SR, Moreira FA. Roles of cannabinoid CB1 and CB2 receptors in the modulation of psychostimulant responses. Acta Neuropsychiatr 2024; 36:67-77. [PMID: 35993329 DOI: 10.1017/neu.2022.23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Addiction to psychostimulant drugs, such as cocaine, D-amphetamine, and methamphetamine, is a public health issue that substantially contributes to the global burden of disease. Psychostimulant drugs promote an increase in dopamine levels within the mesocorticolimbic system, which is central to the rewarding properties of such drugs. Cannabinoid receptors (CB1R and CB2R) are expressed in the main areas of this system and implicated in the neuronal mechanisms underlying the rewarding effect of psychostimulant drugs. Here, we reviewed studies focusing on pharmacological intervention targeting cannabinoid CB1R and CB2R and their interaction in the modulation of psychostimulant responses.
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Affiliation(s)
- P H Gobira
- Department of Biomolecular Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - S R Joca
- Department of Biomolecular Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - F A Moreira
- Department of Pharmacology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
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Marcus MM, Banks ML. Effects of environmental and pharmacological manipulations on cocaine-vs-negative reinforcer choice in male and female rats. Psychopharmacology (Berl) 2023; 240:1677-1689. [PMID: 37340053 PMCID: PMC11162248 DOI: 10.1007/s00213-023-06404-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Accepted: 06/08/2023] [Indexed: 06/22/2023]
Abstract
RATIONALE The adverse consequences of human addictive drug use could be the result of either addictive drug consumption resulting in punishment (e.g., incarceration) or failure to engage in negative-reinforced behaviors that might compete with drug-maintained behaviors (e.g., contingency management strategies that reset payment amounts for drug free urines). OBJECTIVE The goal of the present study was to establish a discrete-trial cocaine-vs-negative reinforcer (SNR) choice procedure where rats were presented with a simplified model of this conflict: choose negative reinforcement (i.e., escape or avoid foot shock) or choose an intravenous (IV) cocaine infusion followed by an inescapable shock. METHODS Responding was maintained in male and female rats by IV cocaine infusions (0.32-1.8 mg/kg/inf) and a SNR (0.1-0.7 mA shock) under a discrete-trial concurrent "choice" schedule during daily sessions. Following parametric reinforcer magnitude and response requirement experiments, the effects of 12 h extended access cocaine self-administration and acute diazepam (0.32-10 mg/kg, IP) pretreatment were determined on cocaine-vs-SNR choice. RESULTS Negative reinforcement was chosen over all cocaine doses. Lowering shock magnitude or increasing SNR response requirement failed to promote behavioral reallocation towards cocaine. Extended access cocaine self-administration sessions resulted in high daily cocaine intakes but failed to significantly increase cocaine choice in all (19) but one rat. Acute diazepam pretreatment also did not alter choice behavior up to doses that produced behavioral depression. CONCLUSIONS These results suggest that SNRs may be a source of reinforcement that effectively compete with and mitigate maladaptive addictive drug-maintained behaviors in the general population.
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Affiliation(s)
- Madison M Marcus
- Department of Pharmacology and Toxicology, Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, USA
| | - Matthew L Banks
- Department of Pharmacology and Toxicology, Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, USA.
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Templeton TJ, Diarra S, Gilpin NW. Sex differences in cocaine self-administration by Wistar rats after predator odor exposure. ADVANCES IN DRUG AND ALCOHOL RESEARCH 2023; 3:11245. [PMID: 37842228 PMCID: PMC10571484 DOI: 10.3389/adar.2023.11245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2023]
Abstract
Traumatic stress disorders are defined in part by persistent avoidance of trauma-related contexts. Our lab uses a preclinical model of traumatic stress using predator odor (i.e., bobcat urine) in which some but not all rats exhibit persistent avoidance of odor-paired stimuli, similar to what is seen in humans. Bobcat urine exposure increases alcohol consumption in male Avoider rats, but it has not been tested for its effects on intake of other drugs. Here, we tested the effect of bobcat urine exposure on cocaine self-administration in adult male and female Wistar rats. We did not observe any effect of bobcat urine exposure on cocaine self-administration in male or female rats. We observed that (1) female rats with long access (6 hours) to cocaine self-administer more cocaine than long-access males, (2) long-access males and females exhibit escalation of cocaine intake over time, (3) stressed rats gain less weight than unstressed rats following acute predator odor exposure, (4) baseline cocaine self-administration is predictive of subsequent cocaine self-administration. The results of this study may inform future work on predator odor effects on cocaine self-administration.
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Affiliation(s)
- Taylor J Templeton
- Department of Physiology, Louisiana State University Health Sciences Center, New Orleans, LA 70112
| | - Siga Diarra
- Department of Physiology, Louisiana State University Health Sciences Center, New Orleans, LA 70112
| | - Nicholas W Gilpin
- Department of Physiology, Louisiana State University Health Sciences Center, New Orleans, LA 70112
- Neuroscience Center of Excellence, Louisiana State University Health Sciences Center, New Orleans, LA 70112
- Alcohol and Drug Abuse Center of Excellence, Louisiana State University Health Sciences Center, New Orleans, LA 70112
- Southeast Louisiana VA Healthcare System, New Orleans, LA 70119
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Templeton TJ, Diarra S, Gilpin NW. Sex differences in cocaine self-administration by Wistar rats after predator odor exposure. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.26.530127. [PMID: 36909634 PMCID: PMC10002624 DOI: 10.1101/2023.02.26.530127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/03/2023]
Abstract
Traumatic stress disorders are defined in part by persistent avoidance of trauma-related contexts. Our lab uses a preclinical model of traumatic stress using predator odor (i.e., bobcat urine) in which some but not all rats exhibit persistent avoidance of odor-paired stimuli, similar to what is seen in humans. Bobcat urine exposure increases alcohol consumption in male Avoider rats, but it has not been tested for its effects on intake of other drugs. Here, we tested the effect of bobcat urine exposure on cocaine self-administration in adult male and female Wistar rats. We did not observe any effect of bobcat urine exposure on cocaine self-administration in male or female rats. We observed that (1) female rats with long access (6 hours) to cocaine self-administer more cocaine than long-access males, (2) long-access males and females exhibit escalation of cocaine intake over time, (3) stressed rats gain less weight than unstressed rats following acute predator odor exposure, (4) baseline cocaine self-administration is predictive of subsequent cocaine self-administration. The results of this study may inform future work on predator odor effects on cocaine self-administration.
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Jastrzębska J, Frankowska M, Smaga I, Hubalewska-Mazgaj M, Suder A, Pieniążek R, Przegaliński E, Filip M. Evaluation of the 5-HT 2C receptor drugs RO 60-0175, WAY 161503 and mirtazepine in a preclinical model of comorbidity of depression and cocaine addiction. Pharmacol Rep 2023; 75:99-118. [PMID: 36374478 PMCID: PMC9889480 DOI: 10.1007/s43440-022-00428-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 10/20/2022] [Accepted: 10/25/2022] [Indexed: 11/16/2022]
Abstract
BACKGROUND Epidemiological data indicate a high rate of comorbidity of depression and cocaine use disorder (CUD). The role of serotonin 2C (5-HT2C) receptors in the mechanisms responsible for the coexistence of depression and CUD was not investigated. METHODS We combined bilateral olfactory bulbectomy (OBX), an animal model of depression, with intravenous cocaine self-administration and extinction/reinstatement in male rats to investigate two 5-HT2C receptor agonists (Ro 60-0175 (RO) and WAY 161503 (WAY)) and the 5-HT2C-receptor preferring antagonist mirtazapine (MIR; an antidepressant), with the goal of determining whether these drugs alter cocaine-induced reinforcement and seeking behaviors. Additionally, neurochemical analyses were performed following cocaine self-administration and its abstinence period in the brain structures in OBX rats and SHAM-operated controls. RESULTS Acute administration of RO reduced, while WAY non-significantly attenuated cocaine reinforcement in both rat phenotypes. Moreover, RO or WAY protected against cocaine-seeking behavior after acute or after repeated drug administration during extinction training in OBX and SHAM rats. By contrast, acutely administered MIR did not alter cocaine reinforcement in both rat phenotypes, while it's acute (but not repeated) pretreatment reduced cocaine-seeking in OBX and SHAM rats. In neurochemical analyses, cocaine reinforcement increased 5-HT2C receptor levels in the ventral hippocampus; a preexisting depression-like phenotype enhanced this effect. The 10-daily cocaine abstinence reduced 5-HT2C receptor expression in the dorsolateral striatum, while the coexistence of depression and CUD enhanced local receptor expression. CONCLUSION The results support a key role of 5-HT2C receptors for treating CUD and comorbid depression and CUD. They may be backs the further research of pharmacological strategies with drug targeting receptors.
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Affiliation(s)
- Joanna Jastrzębska
- Maj Institute of Pharmacology, Department of Drug Addiction Pharmacology, Polish Academy of Sciences, Smętna 12, 31-343 Kraków, Poland
| | - Małgorzata Frankowska
- Maj Institute of Pharmacology, Department of Drug Addiction Pharmacology, Polish Academy of Sciences, Smętna 12, 31-343 Kraków, Poland
| | - Irena Smaga
- Maj Institute of Pharmacology, Department of Drug Addiction Pharmacology, Polish Academy of Sciences, Smętna 12, 31-343 Kraków, Poland
| | - Magdalena Hubalewska-Mazgaj
- Maj Institute of Pharmacology, Department of Drug Addiction Pharmacology, Polish Academy of Sciences, Smętna 12, 31-343 Kraków, Poland
| | - Agata Suder
- Maj Institute of Pharmacology, Department of Drug Addiction Pharmacology, Polish Academy of Sciences, Smętna 12, 31-343 Kraków, Poland
| | - Renata Pieniążek
- Maj Institute of Pharmacology, Department of Drug Addiction Pharmacology, Polish Academy of Sciences, Smętna 12, 31-343 Kraków, Poland
| | - Edmund Przegaliński
- Maj Institute of Pharmacology, Department of Drug Addiction Pharmacology, Polish Academy of Sciences, Smętna 12, 31-343 Kraków, Poland
| | - Małgorzata Filip
- Maj Institute of Pharmacology, Department of Drug Addiction Pharmacology, Polish Academy of Sciences, Smętna 12, 31-343 Kraków, Poland
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Cippitelli A, Zribi G, Toll L. PPL-103: A mixed opioid partial agonist with desirable anti-cocaine properties. Prog Neuropsychopharmacol Biol Psychiatry 2022; 119:110599. [PMID: 35798174 DOI: 10.1016/j.pnpbp.2022.110599] [Citation(s) in RCA: 2] [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: 02/28/2022] [Revised: 06/27/2022] [Accepted: 06/30/2022] [Indexed: 11/19/2022]
Abstract
Cocaine use disorder (CUD) is a persistent public health problem for which no effective medications are available. PPL-103 is an opioid receptor ligand with partial agonist activity at mu, kappa and delta opioid receptors, with a greater efficacy for kappa and low efficacy at mu receptors. Because chronic cocaine use induces changes in the kappa opioid receptor/dynorphin system, we hypothesized that a kappa partial agonist, such as PPL-103, would attenuate the aversive properties of the upregulated kappa system, resulting in effective treatment approach for CUD. We tested the effects of PPL-103 on cocaine self-administration models that recapitulate core aspects of CUD in humans. We found that PPL-103 reduced both long and short access cocaine self-administration, motivation to respond for cocaine, and binge-like cocaine taking, in rats. Operant responding for food, fentanyl and locomotor behavior were not altered at doses that decreased cocaine infusions. Repeated PPL-103 treatment did not lead to tolerance development. PPL-103 also reduced both priming- and cue-induced reinstatement of cocaine seeking, being more effective in the former. Surprisingly, PPL-103 reduced self-administration parameters and reinstatement in rats previously treated with the long-acting kappa receptor antagonist JDTic more potently than in non-JDTic treated animals, whereas naltrexone injected to rats subsequent to JDTic administration increased self-administration, suggesting that the partial mu agonist activity, rather than kappa agonism is important for reduction in cocaine taking and seeking. However, partial kappa activation seems to increase safety by limiting dysphoria, tolerance and addiction development. PPL-103 displays a desirable profile as a possible CUD pharmacotherapy.
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Affiliation(s)
- Andrea Cippitelli
- Biomedical Science Department, Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL, United States.
| | - Gilles Zribi
- Biomedical Science Department, Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL, United States
| | - Lawrence Toll
- Biomedical Science Department, Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL, United States
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From concepts to treatment: a dialog between a preclinical researcher and a clinician in addiction medicine. Transl Psychiatry 2022; 12:401. [PMID: 36130939 PMCID: PMC9492712 DOI: 10.1038/s41398-022-02177-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 09/06/2022] [Accepted: 09/12/2022] [Indexed: 11/08/2022] Open
Abstract
The debate surrounding the brain disease model and the associated questioning of the relevance of animal models is polarizing the field of addiction, and tends to widen the gap between preclinical research and addiction medicine. Here, we aimed at bridging this gap by establishing a dialog between a preclinical researcher and a clinician in addiction medicine. Our objective was to evaluate animal models and the neuroscientific conceptualization of addiction in light of alcohol or drug dependence and treatment in patients struggling with an addiction. We sought to determine how preclinical research influenced addiction medicine over past decades, and reciprocally, what can preclinical researchers learn from addiction medicine that could lead to more effective approaches. In this dialog, we talk about the co-evolution of addiction concepts and treatments from neuroscientific and medical perspectives. This dialog illustrates the reciprocal influences and mutual enrichment between the two disciplines and reveals that, although preclinical research might not produce new pharmacotherapies, it does shape the theoretical conceptualization of addiction and could thereby contribute to the implementation of therapeutic approaches.
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Involvement of the ghrelin system in the maintenance and reinstatement of cocaine-motivated behaviors: a role of adrenergic action at peripheral β1 receptors. Neuropsychopharmacology 2022; 47:1449-1460. [PMID: 34923576 PMCID: PMC9206024 DOI: 10.1038/s41386-021-01249-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 11/22/2021] [Accepted: 11/28/2021] [Indexed: 12/30/2022]
Abstract
Cocaine addiction is a significant medical and public concern. Despite decades of research effort, development of pharmacotherapy for cocaine use disorder remains largely unsuccessful. This may be partially due to insufficient understanding of the complex biological mechanisms involved in the pathophysiology of this disorder. In the present study, we show that: (1) elevation of ghrelin by cocaine plays a critical role in maintenance of cocaine self-administration and cocaine-seeking motivated by cocaine-conditioned stimuli; (2) acquisition of cocaine-taking behavior is associated with the acquisition of stimulatory effects of cocaine by cocaine-conditioned stimuli on ghrelin secretion, and with an upregulation of ghrelin receptor mRNA levels in the ventral tegmental area (VTA); (3) blockade of ghrelin signaling by pretreatment with JMV2959, a selective ghrelin receptor antagonist, dose-dependently inhibits reinstatement of cocaine-seeking triggered by either cocaine or yohimbine in behaviorally extinguished animals with a history of cocaine self-administration; (4) JMV2959 pretreatment also inhibits brain stimulation reward (BSR) and cocaine-potentiated BSR maintained by optogenetic stimulation of VTA dopamine neurons in DAT-Cre mice; (5) blockade of peripheral adrenergic β1 receptors by atenolol potently attenuates the elevation in circulating ghrelin induced by cocaine and inhibits cocaine self-administration and cocaine reinstatement triggered by cocaine. These findings demonstrate that the endogenous ghrelin system plays an important role in cocaine-related addictive behaviors and suggest that manipulating and targeting this system may be viable for mitigating cocaine use disorder.
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George BE, Barth SH, Kuiper LB, Holleran KM, Lacy RT, Raab-Graham KF, Jones SR. Enhanced heroin self-administration and distinct dopamine adaptations in female rats. Neuropsychopharmacology 2021; 46:1724-1733. [PMID: 34040157 PMCID: PMC8358024 DOI: 10.1038/s41386-021-01035-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 05/03/2021] [Accepted: 05/07/2021] [Indexed: 02/04/2023]
Abstract
Increasing evidence suggests that females are more vulnerable to the harmful effects of drugs of abuse, including opioids. Additionally, rates of heroin-related deaths substantially increased in females from 1999 to 2017 [1], underscoring the need to evaluate sex differences in heroin vulnerability. Moreover, the neurobiological substrates underlying sexually dimorphic responding to heroin are not fully defined. Thus, we evaluated male and female Long Evans rats on acquisition, dose-responsiveness, and seeking for heroin self-administration (SA) as well as using a long access model to assess escalation of intake at low and high doses of heroin, 0.025 and 0.1 mg/kg/inf, respectively. We paired this with ex vivo fast-scan cyclic voltammetry (FSCV) in the medial nucleus accumbens (NAc) shell and quantification of mu-opioid receptor (MOR) protein in the ventral tegmental area (VTA) and NAc. While males and females had similar heroin SA acquisition rates, females displayed increased responding and intake across doses, seeking for heroin, and escalation on long access. However, we found that males and females had similar expression levels of MORs in the VTA and NAc, regardless of heroin exposure. FSCV results revealed that heroin exposure did not change single-pulse elicited dopamine release, but caused an increase in dopamine transporter activity in both males and females compared to their naïve counterparts. Phasic-like stimulations elicited robust increases in dopamine release in heroin-exposed females compared to heroin-naïve females, with no differences seen in males. Together, our results suggest that differential adaptations of dopamine terminals may underlie the increased heroin SA behaviors seen in females.
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Affiliation(s)
- Brianna E. George
- grid.241167.70000 0001 2185 3318Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, NC USA
| | - Samuel H. Barth
- grid.241167.70000 0001 2185 3318Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, NC USA
| | - Lindsey B. Kuiper
- grid.241167.70000 0001 2185 3318Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, NC USA
| | - Katherine M. Holleran
- grid.241167.70000 0001 2185 3318Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, NC USA
| | - Ryan T. Lacy
- grid.256069.eDepartment of Psychology, Franklin and Marshall College, Lancaster, PA USA
| | - Kimberly F. Raab-Graham
- grid.241167.70000 0001 2185 3318Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, NC USA
| | - Sara R. Jones
- grid.241167.70000 0001 2185 3318Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, NC USA
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Vanderschuren LJMJ, Ahmed SH. Animal Models of the Behavioral Symptoms of Substance Use Disorders. Cold Spring Harb Perspect Med 2021; 11:cshperspect.a040287. [PMID: 32513674 PMCID: PMC8327824 DOI: 10.1101/cshperspect.a040287] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
To more effectively manage substance use disorders, it is imperative to understand the neural, genetic, and psychological underpinnings of addictive behavior. To contribute to this understanding, considerable efforts have been made to develop translational animal models that capture key behavioral characteristics of addiction on the basis of DSM5 criteria of substance use disorders. In this review, we summarize empirical evidence for the occurrence of addiction-like behavior in animals. These symptoms include escalation of drug use, neurocognitive deficits, resistance to extinction, exaggerated motivation for drugs, increased reinstatement of drug seeking after extinction, preference for drugs over nondrug rewards, and resistance to punishment. The occurrence of addiction-like behavior in laboratory animals has opened the opportunity to investigate the neural, genetic, and psychological background of key aspects of addiction, which may ultimately contribute to the prevention and treatment of substance use disorders.
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Affiliation(s)
- Louk J M J Vanderschuren
- Department of Animals in Science and Society, Division of Behavioural Neuroscience, Faculty of Veterinary Medicine, Utrecht University, 3584 CM Utrecht, the Netherlands
| | - Serge H Ahmed
- Université de Bordeaux, Bordeaux Neurocampus, Institut des Maladies Neurodégénératives, CNRS UMR 5293, F-33000 Bordeaux, France
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Malone SG, Keller PS, Hammerslag LR, Bardo MT. Escalation and reinstatement of fentanyl self-administration in male and female rats. Psychopharmacology (Berl) 2021; 238:2261-2273. [PMID: 33895852 PMCID: PMC10332850 DOI: 10.1007/s00213-021-05850-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 04/12/2021] [Indexed: 11/30/2022]
Abstract
RATIONALE Escalation of drug intake and craving are two DSM-5 hallmark symptoms of opioid use disorder (OUD). OBJECTIVES This study determined if escalation of intake as modeled by long access (LgA) self-administration (SA) and craving measured by reinstatement are related. METHODS Adult male and female Sprague-Dawley rats were trained to self-administer fentanyl across 7 daily 1-h short access (ShA) sessions, followed by 21 SA sessions of either 1- or 6-h duration (ShA or LgA). Following 14 1-h extinction sessions, Experiment 1 assessed reinstatement induced by either fentanyl (10 or 30 µg/kg) or yohimbine (1 or 2 mg/kg), and Experiment 2 assessed reinstatement induced by a drug-associated cue light. RESULTS Females acquired fentanyl SA faster than males. When shifted to LgA sessions, LgA rats escalated fentanyl intake, but ShA rats did not; no reliable sex difference in the rate of escalation was observed. In extinction, compared to ShA rats, LgA rats initially responded less and showed less decay of responding across sessions. A priming injection of fentanyl induced reinstatement, with LgA rats reinstating more than ShA rats at the 30 µg/kg dose. Yohimbine (1 mg/kg) also induced reinstatement, but there was no effect of access group or sex. With cue-induced reinstatement, LgA females reinstated less than LgA males and ShA females. CONCLUSION Among the different reinstatement tests assessed, escalation of fentanyl SA increased only drug-primed reinstatement, suggesting a limited relationship between escalation of drug intake and craving (reinstatement) for OUD.
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Affiliation(s)
- Samantha G Malone
- Department of Psychology, University of Kentucky, Lexington, KY, USA
| | - Peggy S Keller
- Department of Psychology, University of Kentucky, Lexington, KY, USA
| | | | - Michael T Bardo
- Department of Psychology, University of Kentucky, Lexington, KY, USA.
- Biomedical Biological Science Research Building, University of Kentucky, Room 447, 741 S. Limestone, Lexington, KY, 40536-0509, USA.
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Windisch KA, Morochnik M, Reed B, Kreek MJ. Nalmefene, a mu opioid receptor antagonist/kappa opioid receptor partial agonist, potentiates cocaine motivation but not intake with extended access self-administration in adult male mice. Neuropharmacology 2021; 192:108590. [PMID: 33974940 DOI: 10.1016/j.neuropharm.2021.108590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 04/20/2021] [Accepted: 04/25/2021] [Indexed: 11/30/2022]
Abstract
The mu opioid receptor antagonist/kappa opioid receptor (KOR) partial agonist nalmefene (NMF), a close structural analog of naltrexone (NTX), has been shown to reduce cocaine reward in preclinical models. Given the greater KOR potency and improved bioavailability compared to NTX, NMF may be a promising pharmacotherapeutic for cocaine use disorder (CUD). Here we examine the effects of NMF pretreatment on chronic daily extended access (4h) cocaine intravenous self-administration (IVSA) in adult male C57Bl/6J mice. METHODS separate groups of mice had daily 4h cocaine IVSA sessions (0.25 or 0.5 mg/kg/inf, FR1) for 14 days. Starting on day 8, mice were pretreated with NMF (0, 1, or 10 mg/kg) 30m before each session. A separate group of mice acquired cocaine IVSA [seven days FR1 then four FR3 of 4h daily sessions (0.5 mg/kg/inf)] prior to a single progressive ratio 3 session to examine the effect of 1 mg/kg NMF on cocaine motivation. RESULTS No significant effect of NMF pretreatment on cocaine intake was observed. Acute pretreatment of 1 mg/kg NMF significantly potentiated cocaine motivation as measured by progressive ratio breakpoint. CONCLUSIONS NMF did not significantly attenuate cocaine intake and increased motivation for cocaine suggesting that NMF may not be suitable for non-abstinent CUD patients. Further research is needed with KOR selective partial or full agonists to determine their effect on cocaine reinforcement.
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Affiliation(s)
- Kyle A Windisch
- Laboratory of the Biology of Addictive Diseases, The Rockefeller University, 1230 York Avenue, New York, NY, 10065, USA.
| | - Michelle Morochnik
- Laboratory of the Biology of Addictive Diseases, The Rockefeller University, 1230 York Avenue, New York, NY, 10065, USA
| | - Brian Reed
- Laboratory of the Biology of Addictive Diseases, The Rockefeller University, 1230 York Avenue, New York, NY, 10065, USA
| | - Mary Jeanne Kreek
- Laboratory of the Biology of Addictive Diseases, The Rockefeller University, 1230 York Avenue, New York, NY, 10065, USA
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Marusich JA, Gay EA, Watson SL, Blough BE. Alpha-pyrrolidinopentiophenone and mephedrone self-administration produce differential neurochemical changes following short- or long-access conditions in rats. Eur J Pharmacol 2021; 897:173935. [PMID: 33577836 PMCID: PMC7965342 DOI: 10.1016/j.ejphar.2021.173935] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 01/07/2021] [Accepted: 02/04/2021] [Indexed: 12/15/2022]
Abstract
Stimulant-induced neurochemical changes may occur at different times for different brain regions or neurotransmitter systems. This study sought to examine the behavioral and neurochemical effects of extended access to α-pyrrolidinopentiophenone (α-PVP) and 4-methylmethcathinone (4MMC). Male and female Sprague-Dawley rats were trained to self-administer α-PVP (0.1 mg/kg/infusion) or 4MMC (0.5 mg/kg/infusion) through autoshaping, and then self-administered for 21 days during 1 h (short access; ShA) or 6 h (long access; LgA) sessions. Separate rats were assigned to a naïve control group. Amygdala, hippocampus, hypothalamus, prefrontal cortex (PFC), striatum, and thalamus were extracted, and tissue was analyzed with electrochemical detection and liquid chromatography mass spectrometry. Rats acquired self-administration of α-PVP and 4MMC, and LgA rats showed more escalation of self-administration than ShA rats. Synthetic cathinone administration produced several effects on neurotransmitters. LgA self-administration of α-PVP increased 5-HIAA levels in all brain regions, compared to control. In contrast, both LgA and ShA 4MMC self-administration decreased 5-HT and 5-HIAA levels in most brain regions. LgA exposure to both synthetic cathinones increased DOPAC levels in hypothalamus and striatum, and increased HVA levels in striatum compared to control. LgA self-administration of either synthetic cathinone produced region-specific increases in NE levels, whereas ShA self-administration lowered NE levels in select locations compared to control. These alterations in neurotransmitter levels indicate that synthetic cathinone use may produce differential neurochemical changes during the transition from use to abuse, and that 21 days of self-administration only models the beginning stages of dysregulated drug intake.
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Affiliation(s)
- Julie A Marusich
- Center for Drug Discovery, RTI International, 3040 Cornwallis Rd, Research Triangle Park, NC, 27709, USA.
| | - Elaine A Gay
- Center for Drug Discovery, RTI International, 3040 Cornwallis Rd, Research Triangle Park, NC, 27709, USA
| | - Scott L Watson
- Center for Drug Discovery, RTI International, 3040 Cornwallis Rd, Research Triangle Park, NC, 27709, USA
| | - Bruce E Blough
- Center for Drug Discovery, RTI International, 3040 Cornwallis Rd, Research Triangle Park, NC, 27709, USA
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Cippitelli A, Barnes M, Zaveri NT, Toll L. Potent and selective NOP receptor activation reduces cocaine self-administration in rats by lowering hedonic set point. Addict Biol 2020; 25:e12844. [PMID: 31709687 DOI: 10.1111/adb.12844] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 08/29/2019] [Accepted: 09/30/2019] [Indexed: 12/16/2022]
Abstract
Developing new medications for the treatment of cocaine dependence continues to be a research priority. Compelling evidence indicates that mixed opioid receptor agonists, particularly bifunctional compounds that target nociceptin/orphanin FQ peptide (NOP) and mu opioid receptors, may be useful for the treatment of cocaine addiction. Here, we verify that potent and selective pharmacological activation of NOP receptors is sufficient to reduce relevant facets of cocaine addiction in animal models. Accordingly, we determined whether systemic injections of the small molecule AT-312 (0, 1, 3 mg/kg) could reduce operant cocaine self-administration, motivation for cocaine, and vulnerability to cocaine relapse in rats. Results indicate that a potent and selective NOP receptor agonist was equally efficacious in reducing the number of cocaine infusions in short (1-hour), as well as long (6-hour) access sessions. When tested on an economic-demand reinforcement schedule, AT-312 reduced Q0 , the parameter that describes the amount of drug consumed at zero price, while leaving the parameter α, a measure of motivation for drug consumption, unaltered. Furthermore, AT-312 successfully reduced conditioned reinstatement of cocaine seeking. In contrast, the NOP receptor agonist did not modify food self-administration. Blockade of the NOP receptor with the antagonist SB-612111 prevented the effect of AT-312 in decreasing cocaine-reinforced responding under a 2-hour fixed ratio 1 schedule, suggesting a NOP receptor-mediated mechanism. This work demonstrates that potent and selective activation of NOP receptors is sufficient to decrease cocaine taking and seeking behaviors in rats.
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Affiliation(s)
- Andrea Cippitelli
- Biomedical Science Department Charles E. Schmidt College of Medicine Florida Atlantic University Boca Raton FL United States
| | - Megan Barnes
- Biomedical Science Department Charles E. Schmidt College of Medicine Florida Atlantic University Boca Raton FL United States
| | | | - Lawrence Toll
- Biomedical Science Department Charles E. Schmidt College of Medicine Florida Atlantic University Boca Raton FL United States
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15
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Caffino L, Verheij MMM, Roversi K, Targa G, Mottarlini F, Popik P, Nikiforuk A, Golebiowska J, Fumagalli F, Homberg JR. Hypersensitivity to amphetamine's psychomotor and reinforcing effects in serotonin transporter knockout rats: Glutamate in the nucleus accumbens. Br J Pharmacol 2020; 177:4532-4547. [PMID: 32721055 PMCID: PMC7484509 DOI: 10.1111/bph.15211] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Revised: 07/14/2020] [Accepted: 07/15/2020] [Indexed: 12/22/2022] Open
Abstract
Background and Purpose Amphetamine (AMPH) use disorder is a serious health concern, but, surprisingly, little is known about the vulnerability to the moderate and compulsive use of this psychostimulant and its underlying mechanisms. Previous research showed that inherited serotonin transporter (SERT) down‐regulation increases the motor response to cocaine, as well as moderate (as measured during daily 1‐h self‐administration sessions) and compulsive (as measured during daily 6‐h self‐administration sessions) intake of this psychostimulant. Here, we sought to investigate whether these findings generalize to AMPH and the underlying mechanisms in the nucleus accumbens. Experimental Approach In serotonin transporter knockout (SERT−/−) and wild‐type control (SERT+/+) rats, we assessed the locomotor response to acute AMPH and i.v. AMPH self‐administration under short access (ShA: 1‐h daily sessions) and long access (LgA: 6‐h daily sessions) conditions. Twenty‐four hours after AMPH self‐administration, we analysed the expression of glutamate system components in the nucleus accumbens shell and core. Key Results We found that SERT−/− animals displayed an increased AMPH‐induced locomotor response and increased AMPH self‐administration under LgA but not ShA conditions. Further, we observed changes in the vesicular and glial glutamate transporters, NMDA and AMPA receptor subunits, and their respective postsynaptic scaffolding proteins as function of SERT genotype and AMPH exposure (baseline, ShA, and LgA), specifically in the nucleus accumbens shell. Conclusion and Implications We demonstrate that SERT gene deletion increases the psychomotor and reinforcing effects of AMPH and that the latter is potentially mediated, at least in part, by homeostatic changes in the glutamatergic synapse of the nucleus accumbens shell and/or core.
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Affiliation(s)
- Lucia Caffino
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milan, Italy
| | - Michel M M Verheij
- Department of Cognitive Neuroscience, Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Karine Roversi
- Department of Cognitive Neuroscience, Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Giorgia Targa
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milan, Italy
| | - Francesca Mottarlini
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milan, Italy
| | - Piotr Popik
- Department of Behavioural Neuroscience and Drug Development, Maj Institute of Pharmacology, Polish Academy of Sciences, Krakow, Poland
| | - Agnieska Nikiforuk
- Department of Behavioural Neuroscience and Drug Development, Maj Institute of Pharmacology, Polish Academy of Sciences, Krakow, Poland
| | - Joanna Golebiowska
- Department of Behavioural Neuroscience and Drug Development, Maj Institute of Pharmacology, Polish Academy of Sciences, Krakow, Poland
| | - Fabio Fumagalli
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milan, Italy
| | - Judith R Homberg
- Department of Cognitive Neuroscience, Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
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16
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Kearns DN, Silberberg A. Opening the cocaine economy by providing within-session access to a cheaper source of cocaine makes demand for it more elastic. Behav Pharmacol 2020; 31:448-457. [PMID: 31625978 PMCID: PMC7182474 DOI: 10.1097/fbp.0000000000000510] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Previous studies found that opening the cocaine economy by providing postsession access to cocaine had no effect on animals' demand for cocaine, whereas postsession access to saccharin or food made demand for these nondrug reinforcers more elastic. It is possible that there was no effect of economy type on cocaine taking in these earlier studies because of the delay to the postsession cocaine in the open economy. The present experiment tested whether forming an open economy by providing additional within-session cocaine, rather than postsession cocaine, would make rats' demand for cocaine more elastic. Saccharin was used as a nondrug comparison reinforcer. Three groups of rats pressed one lever for cocaine and one for saccharin on an ascending series of fixed ratio (FR) schedules where the number of responses required per reinforcer increased from 1 to 48 over sessions. In the open cocaine and open saccharin economy groups, rats had occasional access during the session to a third lever where cocaine or saccharin reinforcers, respectively, were always available on an FR-1 schedule. The main finding was that demand for cocaine was more elastic in the open cocaine economy group than in either of the other groups. Demand for saccharin was more elastic in the open saccharin economy group than in the open cocaine economy group. This study shows that cocaine taking is sensitive to economy type when the additional source of cocaine in an open economy is available close in time to when rats work for cocaine.
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Affiliation(s)
- David N Kearns
- Psychology Department, American University, Washington DC, USA
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17
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Cocker PJ, Rotge J, Daniel M, Belin‐Rauscent A, Belin D. Impaired decision making following escalation of cocaine self-administration predicts vulnerability to relapse in rats. Addict Biol 2020; 25:e12738. [PMID: 30848014 PMCID: PMC7187387 DOI: 10.1111/adb.12738] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Revised: 02/01/2019] [Accepted: 02/01/2019] [Indexed: 01/12/2023]
Abstract
Impairments in cost‐benefit decision making represent a cardinal feature of drug addiction. However, whether these alterations predate drug exposure, thereby contributing to facilitating loss of control over drug intake, or alternatively arise as a result of drug use and subsequently confer vulnerability to relapse has yet to be determined. Male Sprague‐Dawley rats were trained to self‐administer (SA) cocaine during 19 daily long‐access (12‐h) sessions; conditions reliably shown to promote escalation. One week after cocaine SA, rats underwent an extinction/relapse test immediately followed by conditioned stimuli–, stress‐, and drug‐primed reinstatement challenges. The influence of escalated cocaine intake on decision making was measured over time by four test sessions of a rodent analogue of the Iowa Gambling Task (rGT), once prior to cocaine exposure and then 1 day, 1 week, and 1 month after the last SA session. Substantial individual variability was observed in the influence of escalated cocaine SA on decision‐making performance. A subset of rats displayed pronounced deficits, while others showed unaffected or even improved performance on the rat Gambling Task (rGT) 24 hours after the last SA session. When challenged with a relapse test after 1 week of forced abstinence, animals that showed impaired decision making following SA displayed an increased propensity to respond for cocaine under extinction. These data suggest that decision‐making deficits in individuals with drug addiction are not antecedent to—but arise as a consequence of—drug exposure. Moreover, these data indicate that susceptibility to the deleterious effects of drugs on decision making confers vulnerability toward relapse.
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Affiliation(s)
| | - Jean‐Yves Rotge
- AP‐HP, Groupe Hospitalier Pitié‐Salpêtrière, Service de Psychiatrie d'Adultes Paris France
- Inserm U1127, CNRS UMR 7225, Sorbonne Université, Institut du Cerveau et de la Moelle, ICM Paris France
| | | | | | - David Belin
- Department of PsychologyUniversity of Cambridge Cambridge UK
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18
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Effects of Kappa opioid receptor blockade by LY2444296 HCl, a selective short-acting antagonist, during chronic extended access cocaine self-administration and re-exposure in rat. Psychopharmacology (Berl) 2020; 237:1147-1160. [PMID: 31915862 DOI: 10.1007/s00213-019-05444-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Accepted: 12/27/2019] [Indexed: 12/14/2022]
Abstract
RATIONALE Cocaine addiction is a chronic brain disease characterized by compulsive drug intake and dysregulation of brain reward systems. Few preclinical studies have modeled the natural longitudinal course of cocaine addiction. Extended access self-administration protocols are powerful tools for modeling the advanced stages of addiction; however, few studies have duration of drug access longer than 12 h/session, potentially limiting their construct validity. Identification of changes in cocaine intake patterns during the development of addictive-like states may allow better treatments for vulnerable subjects. The kappa opioid receptor (KOPr) system has been implicated in the neurobiological regulation of addictive states as well as mood and stress disorders, with selective KOPr antagonists proposed as possible pharmacotherapeutic agents. Chronic cocaine exposure increases the expression of KOPr and its endogenous agonists, the dynorphins, in several brain areas in rodents. OBJECTIVES To examine the behavioral pattern of intake during chronic (14 days) 18 h intravenous cocaine self-administration (0.5 mg/kg/infusion) and the effect of a novel short-acting KOPr antagonist LY2444296 HCl (3 mg/kg) administered during sessions 8 to 14 of chronic 18 h/day cocaine self-administration and prior to a single re-exposure session after 2 cocaine-free withdrawal days. RESULTS Both daily and hourly cocaine intake patterns changed over 14 days of 18 h self-administration. LY pretreatment affected the pattern of self-administration across the second week of extended access cocaine self-administration and prevented the increase in cocaine intake during re-exposure. CONCLUSIONS Overall, the KOPr antagonist attenuated escalated cocaine consumption in a rat model of extended access cocaine self-administration.
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19
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Vassilev P, Avvisati R, Koya E, Badiani A. Distinct Populations of Neurons Activated by Heroin and Cocaine in the Striatum as Assessed by catFISH. eNeuro 2020; 7:ENEURO.0394-19.2019. [PMID: 31937522 PMCID: PMC7005257 DOI: 10.1523/eneuro.0394-19.2019] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 11/30/2019] [Accepted: 12/19/2019] [Indexed: 12/13/2022] Open
Abstract
Despite the still prevailing notion of a shared substrate of action for all addictive drugs, there is evidence suggesting that opioid and psychostimulant drugs differ substantially in terms of their neurobiological and behavioral effects. These differences may reflect separate neural circuits engaged by the two drugs. Here we used the catFISH (cellular compartment analysis of temporal activity by fluorescence in situ hybridization) technique to investigate the degree of overlap between neurons engaged by heroin versus cocaine in adult male Sprague Dawley rats. The catFISH technique is a within-subject procedure that takes advantage of the different transcriptional time course of the immediate-early genes homer 1a and arc to determine to what extent two stimuli separated by an interval of 25 min engage the same neuronal population. We found that throughout the striatal complex the neuronal populations activated by noncontingent intravenous injections of cocaine (800 μg/kg) and heroin (100 and 200 μg/kg), administered at an interval of 25 min from each other, overlapped to a much lesser extent than in the case of two injections of cocaine (800 μg/kg), also 25 min apart. The greatest reduction in overlap between populations activated by cocaine and heroin was in the dorsomedial and dorsolateral striatum (∼30% and ∼22%, respectively, of the overlap observed for the sequence cocaine-cocaine). Our results point toward a significant separation between neuronal populations activated by heroin and cocaine in the striatal complex. We propose that our findings are a proof of concept that these two drugs are encoded differently in a brain area believed to be a common neurobiological substrate to drug abuse.
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Affiliation(s)
- Philip Vassilev
- Sussex Addiction Research and Intervention Centre (SARIC), School of Psychology, University of Sussex, Brighton BN1 9RH, United Kingdom
| | - Riccardo Avvisati
- Sussex Addiction Research and Intervention Centre (SARIC), School of Psychology, University of Sussex, Brighton BN1 9RH, United Kingdom
| | - Eisuke Koya
- Sussex Addiction Research and Intervention Centre (SARIC), School of Psychology, University of Sussex, Brighton BN1 9RH, United Kingdom
| | - Aldo Badiani
- Sussex Addiction Research and Intervention Centre (SARIC), School of Psychology, University of Sussex, Brighton BN1 9RH, United Kingdom
- Department of Physiology and Pharmacology, Sapienza University of Rome, 00185 Rome, Italy
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20
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Caffino L, Verheij MM, Que L, Guo C, Homberg JR, Fumagalli F. Increased cocaine self-administration in rats lacking the serotonin transporter: a role for glutamatergic signaling in the habenula. Addict Biol 2019; 24:1167-1178. [PMID: 30144237 DOI: 10.1111/adb.12673] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Revised: 07/20/2018] [Accepted: 07/30/2018] [Indexed: 12/29/2022]
Abstract
Serotonin (5-HT) and the habenula (Hb) contribute to motivational and emotional states such as depression and drug abuse. The dorsal raphe nucleus, where 5-HT neurons originate, and the Hb are anatomically and reciprocally interconnected. Evidence exists that 5-HT influences Hb glutamatergic transmission. Using serotonin transporter knockout (SERT-/- ) rats, which show depression-like behavior and increased cocaine intake, we investigated the effect of SERT reduction on expression of genes involved in glutamate neurotransmission under both baseline conditions as well as after short-access or long-access cocaine (ShA and LgA, respectively) intake. In cocaine-naïve animals, SERT removal led to reduced baseline Hb mRNA levels of critical determinants of glutamate transmission, such as SLC1A2, the main glutamate transporter and N-methyl-D-aspartate (Grin1, Grin2A and Grin2B) as well as α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (Gria1 and Gria2) receptor subunits, with no changes in the scaffolding protein Dlg4. In response to ShA and LgA cocaine intake, SLC1A2 and Grin1 mRNA levels decreased in SERT+/+ rats to levels equal of those of SERT-/- rats. Our data reveal that increased extracellular levels of 5-HT modulate glutamate neurotransmission in the Hb, serving as critical neurobiological substrate for vulnerability to cocaine addiction.
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Affiliation(s)
- Lucia Caffino
- Department of Pharmacological and Biomolecular SciencesUniversità degli Studi di Milano Italy
| | - Michel M.M. Verheij
- Department of Cognitive Neuroscience, division of Molecular Neurogenetics, Donders Institute for Brain, Cognition and BehaviourRadboud University Nijmegen Medical Centre The Netherlands
- Department of Molecular Animal Physiology, Nijmegen Center for Molecular Life SciencesRadboud University Nijmegen The Netherlands
| | - Lin Que
- Department of Cognitive Neuroscience, division of Molecular Neurogenetics, Donders Institute for Brain, Cognition and BehaviourRadboud University Nijmegen Medical Centre The Netherlands
| | - Chao Guo
- Department of Cognitive Neuroscience, division of Molecular Neurogenetics, Donders Institute for Brain, Cognition and BehaviourRadboud University Nijmegen Medical Centre The Netherlands
| | - Judith R. Homberg
- Department of Cognitive Neuroscience, division of Molecular Neurogenetics, Donders Institute for Brain, Cognition and BehaviourRadboud University Nijmegen Medical Centre The Netherlands
| | - Fabio Fumagalli
- Department of Pharmacological and Biomolecular SciencesUniversità degli Studi di Milano Italy
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21
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Allen CP, Park K, Li A, Volkow ND, Koob GF, Pan Y, Hu X, Du C. Enhanced neuronal and blunted hemodynamic reactivity to cocaine in the prefrontal cortex following extended cocaine access: optical imaging study in anesthetized rats. Addict Biol 2019; 24:485-497. [PMID: 29504647 DOI: 10.1111/adb.12615] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 01/22/2018] [Accepted: 01/26/2018] [Indexed: 12/24/2022]
Abstract
Cocaine addiction is associated with dysfunction of the prefrontal cortex (PFC), which facilitates relapse and compulsive drug taking. To assess if cocaine's effects on both neuronal and vascular activity contribute to PFC dysfunction, we used optical coherence tomography and multi-wavelength laser speckle to measure vascularization and hemodynamics and used GCaMP6f to monitor intracellular Ca2+ levels ([Ca2+ ]in ) as a marker of neuronal activity. Rats were given short (1 hour; ShA) or long (6 hours; LgA) access cocaine self-administration. As expected, LgA but not ShA rats escalated cocaine intake. In naïve rats, acute cocaine decreased oxygenated hemoglobin, increased deoxygenated hemoglobin and reduced cerebral blood flow in PFC, likely due to cocaine-induced vasoconstriction. ShA rats showed enhanced hemodynamic response and slower recovery after cocaine, versus naïve. LgA rats showed a blunted hemodynamic response, but an enhanced PFC neuronal [Ca2+ ]in increase after cocaine challenge associated with drug intake. Both ShA and LgA groups had higher vessel density, indicative of angiogenesis, presumably to compensate for cocaine's vasoconstricting effects. Cocaine self-administration modified the PFC cerebrovascular responses enhancing it in ShA and attenuating it in LgA animals. In contrast, LgA but not ShA animals showed sensitized neuronal reactivity to acute cocaine in the PFC. The opposite changes in hemodynamics (decreased) and neuronal responses (enhanced) in LgA rats indicate that these constitute distinct effects and suggest that the neuronal and not the vascular effects are associated with escalation of cocaine intake in addiction whereas its vascular effect in PFC might contribute to cognitive deficits that increase vulnerability to relapse.
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Affiliation(s)
- Craig P. Allen
- Department of Biomedical EngineeringStony Brook University Stony Brook NY USA
| | - Kicheon Park
- Department of Biomedical EngineeringStony Brook University Stony Brook NY USA
| | - Ang Li
- Department of Biomedical EngineeringStony Brook University Stony Brook NY USA
| | - Nora D. Volkow
- National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health Bethesda MD USA
| | - George F. Koob
- National Institute on Drug Abuse, National Institutes of Health Bethesda MD USA
| | - Yingtian Pan
- Department of Biomedical EngineeringStony Brook University Stony Brook NY USA
| | - Xiu‐Ti Hu
- Department of Immunology and MicrobiologyRush University Medical Center Chicago Il USA
| | - Congwu Du
- Department of Biomedical EngineeringStony Brook University Stony Brook NY USA
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22
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Kim JS, Gunawan T, Tripoli CS, Silberberg A, Kearns DN. The effect of economy type on demand and preference for cocaine and saccharin in rats. Drug Alcohol Depend 2018; 192:150-157. [PMID: 30257224 PMCID: PMC6200639 DOI: 10.1016/j.drugalcdep.2018.08.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 07/13/2018] [Accepted: 08/05/2018] [Indexed: 10/28/2022]
Abstract
BACKGROUND Economy type is an important determinant of reinforcer value. This study investigated the effect of open and closed economies on demand and preference for cocaine and saccharin in rats. METHODS In the first phase, rats were trained to lever press for cocaine infusions or saccharin. The number of presses required for each reinforcer increased across sessions. Cocaine and saccharin economy type was manipulated over groups by varying post-session availability of these reinforcers. One group of rats had three hours' post-session access to unlimited cocaine (open economy). A second group had three hours' post-session access to unlimited saccharin. A third group had no post-session access to either reinforcer (closed economy). In a second phase, rats in the three conditions could make mutually exclusive choices for cocaine or saccharin. RESULTS Post-session access to saccharin caused saccharin demand to become more elastic. Post-session access to cocaine had no effect on demand for cocaine but made demand for saccharin more elastic. Results from the choice phase generally paralleled those from the demand phase, the main finding being that post-session saccharin access caused an increase in cocaine preference. CONCLUSIONS These results show that manipulating economy type can affect cocaine and non-drug reinforcers differently. Opening the saccharin economy decreased saccharin's value. Opening the cocaine economy did not decrease cocaine's value, but instead led to a devaluation of saccharin. These results suggest that cocaine choice may be determined not only by the reinforcers immediately available, but also by those reinforcers' broader contexts of availability.
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Affiliation(s)
- Jung S Kim
- Department of Psychology, American University, 4400 Massachusetts Avenue NW, Washington, DC, 20016, United States
| | - Tommy Gunawan
- Department of Psychology, American University, 4400 Massachusetts Avenue NW, Washington, DC, 20016, United States
| | - Christopher S Tripoli
- Department of Psychology, American University, 4400 Massachusetts Avenue NW, Washington, DC, 20016, United States
| | - Alan Silberberg
- Department of Psychology, American University, 4400 Massachusetts Avenue NW, Washington, DC, 20016, United States
| | - David N Kearns
- Department of Psychology, American University, 4400 Massachusetts Avenue NW, Washington, DC, 20016, United States.
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23
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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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24
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Ploense KL, Li X, Baker-Andresen D, Carr AE, Woodward N, Bagley J, Szumlinski KK, Bredy TW, Kippin TE. Prolonged-access to cocaine induces distinct Homer2 DNA methylation, hydroxymethylation, and transcriptional profiles in the dorsomedial prefrontal cortex of Male Sprague-Dawley rats. Neuropharmacology 2018; 143:299-305. [PMID: 30268522 DOI: 10.1016/j.neuropharm.2018.09.029] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 09/17/2018] [Accepted: 09/20/2018] [Indexed: 12/16/2022]
Abstract
Repeated cocaine administration induces many long-term structural and molecular changes in the dorsal medial prefrontal cortex (dmPFC) and are known to underlie aspects of cocaine-seeking behavior. DNA methylation is a key long-lasting epigenetic determinant of gene expression and is implicated in neuroplasticity, however, the extent to which this epigenetic modification is involved in the neuroplasticity associated with drug addiction has received limited attention. Here, we examine the relation between DNA methylation and gene expression within the dorsal medial prefrontal cortex (dmPFC) following limited cocaine self-administration (1 h/day), prolonged cocaine self-administration (6 h/day), and saline self-administration (1 h/day). Rats were fitted with intravenous catheters and allowed to lever press for saline or cocaine (0.25 mg/kg/0.1 mL infusion) in the different access conditions for 20 days. Prolonged-access rats exhibited escalation in cocaine intake over the course of training, while limited-access rats did not escalate cocaine intake. Additionally, limited-access and prolonged-access rats exhibited unique Homer2 epigenetic profiles and mRNA expression. In prolonged-access rats, Homer2 mRNA levels in the dmPFC were increased, which was accompanied by decreased DNA methylation and p300 binding within the Homer2 promoter. Limited-access animals exhibited decreased DNA methylation, decreased DNA hydroxymethylation, and increased p300 binding within the Homer2 promoter. These data indicate that distinct epigenetic profiles are induced by limited-versus prolonged-access self-administration conditions that contribute to transcriptional profiles and lend support to the notion that covalent modification of DNA is implicated in addiction-like changes in cocaine-seeking behavior.
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Affiliation(s)
- Kyle L Ploense
- Department of Psychological & Brain Sciences, University of California, Santa Barbara, CA, USA; Institute for Collaborative Biotechnology, University of California, Santa Barbara, CA, USA; Department of Chemistry & Biochemistry, University of California, Santa Barbara, CA, USA.
| | - Xiang Li
- Queensland Brain Institute, University of Queensland, St Lucia, QLD, Australia
| | | | - Amanda E Carr
- Department of Psychological & Brain Sciences, University of California, Santa Barbara, CA, USA
| | - Nick Woodward
- Department of Psychological & Brain Sciences, University of California, Santa Barbara, CA, USA
| | - Jared Bagley
- Department of Psychological & Brain Sciences, University of California, Santa Barbara, CA, USA; Department of Psychology, Binghamton University, Binghamton, NY, USA
| | - Karen K Szumlinski
- Department of Psychological & Brain Sciences, University of California, Santa Barbara, CA, USA; Neuroscience Research Institute, University of California, Santa Barbara, CA, USA; Department of Molecular Cellular Developmental Biology, University of California, Santa Barbara, CA, USA
| | - Timothy W Bredy
- Queensland Brain Institute, University of Queensland, St Lucia, QLD, Australia
| | - Tod E Kippin
- Department of Psychological & Brain Sciences, University of California, Santa Barbara, CA, USA; Neuroscience Research Institute, University of California, Santa Barbara, CA, USA; Department of Molecular Cellular Developmental Biology, University of California, Santa Barbara, CA, USA; Institute for Collaborative Biotechnology, University of California, Santa Barbara, CA, USA
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Adolescent cannabinoid exposure induces irritability-like behavior and cocaine cross-sensitization without affecting the escalation of cocaine self-administration in adulthood. Sci Rep 2018; 8:13893. [PMID: 30224774 PMCID: PMC6141462 DOI: 10.1038/s41598-018-31921-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 08/19/2018] [Indexed: 11/26/2022] Open
Abstract
Cannabis use is typically initiated during adolescence and is a significant risk factor for the development of cocaine use in adulthood. However, no preclinical studies have examined the effects of adolescent cannabinoid exposure on cocaine dependence in adulthood using the escalation model of cocaine self-administration and the assessment of negative emotional states. In the present study, we found that exposure to the cannabinoid receptor agonist WIN55,212-2 (WIN) in adolescence produced irritability-like behavior and psychomotor cross-sensitization to cocaine in adolescence. In adulthood, rats were allowed to self-administer cocaine. The acquisition of cocaine self-administration was lower in rats with adolescent WIN exposure compared with controls. However, both WIN-exposed and control rats escalated their cocaine intake at the same rate, had similar responding under a progressive-ratio schedule of reinforcement, and had similar psychomotor responses to cocaine. Interestingly, the increase in irritability-like behavior that was previously observed in adolescence after WIN exposure persisted into adulthood. Whether the persisting increase in irritability-like behavior after WIN exposure has translational relevance remains to be studied. In summary, these results suggest that psychoactive cannabinoid exposure during adolescence is unlikely to have a major effect on the escalation of cocaine intake or the development of compulsive-like responding per se in adulthood in a rat model of cocaine self-administration. However, whether the persisting irritability-like behavior may predispose an individual to mood-related impairments in adulthood or predict such impairments warrants further investigation.
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Verheij MMM, Contet C, Karel P, Latour J, van der Doelen RHA, Geenen B, van Hulten JA, Meyer F, Kozicz T, George O, Koob GF, Homberg JR. Median and Dorsal Raphe Serotonergic Neurons Control Moderate Versus Compulsive Cocaine Intake. Biol Psychiatry 2018; 83:1024-1035. [PMID: 29357981 PMCID: PMC5960600 DOI: 10.1016/j.biopsych.2017.10.031] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Revised: 10/12/2017] [Accepted: 10/18/2017] [Indexed: 01/30/2023]
Abstract
BACKGROUND Reduced expression of the serotonin transporter (SERT) promotes anxiety and cocaine intake in both humans and rats. We tested the hypothesis that median raphe nucleus (MRN) and dorsal raphe nucleus (DRN) serotonergic projections differentially mediate these phenotypes. METHODS We used virally mediated RNA interference to locally downregulate SERT expression and compared the results with those of constitutive SERT knockout. Rats were allowed either short access (ShA) (1 hour) or long access (LgA) (6 hours) to cocaine self-administration to model moderate versus compulsive-like cocaine taking. RESULTS SERT knockdown in the MRN increased cocaine intake selectively under ShA conditions and, like ShA cocaine self-administration, reduced corticotropin-releasing factor (CRF) immunodensity in the paraventricular nucleus of the hypothalamus. In contrast, SERT knockdown in the DRN increased cocaine intake selectively under LgA conditions and, like LgA cocaine self-administration, reduced CRF immunodensity in the central nucleus of the amygdala. SERT knockdown in the MRN or DRN produced anxiety-like behavior, as did withdrawal from ShA or LgA cocaine self-administration. The phenotype of SERT knockout rats was a summation of the phenotypes generated by MRN- and DRN-specific SERT knockdown. CONCLUSIONS Our results highlight a differential role of serotonergic projections arising from the MRN and DRN in the regulation of cocaine intake. We propose that a cocaine-induced shift from MRN-driven serotonergic control of CRF levels in the hypothalamus to DRN-driven serotonergic control of CRF levels in the amygdala may contribute to the transition from moderate to compulsive intake of cocaine.
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Affiliation(s)
- Michel M M Verheij
- Department of Cognitive Neuroscience, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, the Netherlands; Department of Molecular and Animal Physiology, Nijmegen Center for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, Nijmegen, the Netherlands.
| | - Candice Contet
- Department of Molecular and Animal Physiology, Nijmegen Center for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, Nijmegen, the Netherlands
| | - Peter Karel
- Department of Cognitive Neuroscience, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, the Netherlands
| | - Judith Latour
- Department of Cognitive Neuroscience, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, the Netherlands
| | - Rick H A van der Doelen
- Department of Anatomy, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, the Netherlands
| | - Bram Geenen
- Department of Anatomy, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, the Netherlands
| | | | - Francisca Meyer
- Department of Neuroscience, Scripps Research Institute, La Jolla, California
| | - Tamas Kozicz
- Department of Anatomy, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, the Netherlands
| | - Olivier George
- Department of Molecular and Animal Physiology, Nijmegen Center for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, Nijmegen, the Netherlands
| | - George F Koob
- Neurobiology of Addiction Section, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, Maryland
| | - Judith R Homberg
- Department of Cognitive Neuroscience, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, the Netherlands
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Jordan CJ, Andersen SL. Working memory and salivary brain-derived neurotrophic factor as developmental predictors of cocaine seeking in male and female rats. Addict Biol 2018; 23:868-879. [PMID: 28857460 DOI: 10.1111/adb.12535] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Revised: 05/02/2017] [Accepted: 06/12/2017] [Indexed: 12/24/2022]
Abstract
Poor working memory is linked to future risk-taking behaviors. Lifelong risk of habitual drug use is highest in individuals who initiate use in early adolescence. We sought to determine in rats whether juvenile traits, specifically poor working memory and low salivary brain-derived neurotrophic factor (BDNF), are related to elevated cocaine taking and relapse in adolescence and adulthood. On postnatal day (P) 20, working memory was assessed using the novel object recognition task in male and female rats. Saliva was assayed at P20 for BDNF before cocaine self-administration on P28 [0.75 or 0.25 mg/kg/infusion for 30 days under a fixed-ratio (FR) 1 to FR5 schedule] and on P94 before relapse after 30-day abstinence in adulthood. A separate cohort of P28 male rats was assayed for object discrimination and BDNF in saliva and the medial prefrontal cortex and dorsolateral striatum. Novel object discrimination correlated positively with salivary BDNF on P20 and dorsolateral striatum levels, but negatively with medial prefrontal cortex BDNF in male rats. In female rats, P20 salivary BDNF negatively correlated with object discrimination. Salivary BDNF positively correlated across age in male rats. Male rats earned more cocaine (0.75 mg/kg) at FR5 and responded more at relapse than did female rats. These elevated relapse rates in male rats were significantly associated with P20 object discrimination and salivary BDNF. Relapse after 0.75 and 0.25 mg/kg in female rats correlated only with object discrimination. In conclusion, poor working memory and low salivary BDNF in juvenile male rats may represent biomarkers for later cocaine use. Further research is needed to identify biomarkers for risk in male rats.
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Affiliation(s)
- Chloe J. Jordan
- Department of Psychiatry; McLean Hospital, Harvard Medical School; Belmont MA USA
| | - Susan L. Andersen
- Department of Psychiatry; McLean Hospital, Harvard Medical School; Belmont MA USA
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Ploense KL, Vieira P, Bubalo L, Olivarria G, Carr AE, Szumlinski KK, Kippin TE. Contributions of prolonged contingent and non-contingent cocaine exposure to escalation of cocaine intake and glutamatergic gene expression. Psychopharmacology (Berl) 2018; 235:1347-1359. [PMID: 29234834 PMCID: PMC5924572 DOI: 10.1007/s00213-017-4798-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Accepted: 11/01/2017] [Indexed: 01/08/2023]
Abstract
Similar to the pattern observed in people with substance abuse disorders, laboratory animals will exhibit escalation of cocaine intake when the drug is available over prolonged periods of time. Here, we investigated the contribution of behavioral contingency of cocaine administration on escalation of cocaine intake and gene expression in the dorsal medial prefrontal cortex (dmPFC) in adult male rats. Rats were allowed to self-administer intravenous cocaine (0.25 mg/infusion) under either limited cocaine-(1 h/day), prolonged cocaine-(6 h/day), or limited cocaine-(1 h/day) plus yoked cocaine-access (5 h/day); a control group received access to saline (1 h/day). One day after the final self-administration session, the rats were euthanized and the dmPFC was removed for quantification of mRNA expression of critical glutamatergic signaling genes, Homer2, Grin1, and Dlg4, as these genes and brain region have been previously implicated in addiction, learning, and memory. All groups with cocaine-access showed escalated cocaine intake during the first 10 min of each daily session, and within the first 1 h of cocaine administration. Additionally, the limited-access + yoked group exhibited more non-reinforced lever responses during self-administration sessions than the other groups tested. Lastly, Homer2, Grin1, and Dlg4 mRNA were impacted by both duration and mode of cocaine exposure. Only prolonged-access rats exhibited increases in mRNA expression for Homer2, Grin1, and Dlg4 mRNA. Taken together, these findings indicate that both contingent and non-contingent "excessive" cocaine exposure supports escalation behavior, but the behavioral contingency of cocaine-access has distinct effects on the patterning of operant responsiveness and changes in mRNA expression.
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Affiliation(s)
- Kyle L Ploense
- Department of Psychological & Brain Sciences, University of California Santa Barbara, Santa Barbara, CA, 93106-9660, USA.
| | - Philip Vieira
- Department of Psychological & Brain Sciences, University of California Santa Barbara, Santa Barbara, CA, 93106-9660, USA
- Department of Psychology, California State University-Dominguez Hills, Carson, CA, 90747, USA
| | - Lana Bubalo
- Department of Psychological & Brain Sciences, University of California Santa Barbara, Santa Barbara, CA, 93106-9660, USA
| | - Gema Olivarria
- Department of Psychological & Brain Sciences, University of California Santa Barbara, Santa Barbara, CA, 93106-9660, USA
| | - Amanda E Carr
- Department of Psychological & Brain Sciences, University of California Santa Barbara, Santa Barbara, CA, 93106-9660, USA
| | - Karen K Szumlinski
- Department of Psychological & Brain Sciences, University of California Santa Barbara, Santa Barbara, CA, 93106-9660, USA
- Neuroscience Research Institute, University of California Santa Barbara, Santa Barbara, CA, 93106, USA
- Department of Molecular Cellular and Developmental Biology, University of California Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Tod E Kippin
- Department of Psychological & Brain Sciences, University of California Santa Barbara, Santa Barbara, CA, 93106-9660, USA
- Neuroscience Research Institute, University of California Santa Barbara, Santa Barbara, CA, 93106, USA
- Department of Molecular Cellular and Developmental Biology, University of California Santa Barbara, Santa Barbara, CA, 93106, USA
- Institute for Collaborative Biotechnologies, University of California Santa Barbara, Santa Barbara, CA, 93106, USA
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Oh JH, Hwang JY, Hong SI, Ma SX, Seo JY, Lee SY, Kim HC, Jang CG. The new designer drug buphedrone produces rewarding properties via dopamine D1 receptor activation. Addict Biol 2018; 23:69-79. [PMID: 27790823 DOI: 10.1111/adb.12472] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Revised: 09/08/2016] [Accepted: 10/11/2016] [Indexed: 01/20/2023]
Abstract
Substituted cathinones are synthetic analogs of the active components of natural products and are widely abused worldwide. However, the rewarding properties of these agents have not yet been evaluated. In this study, we investigated the abuse potential of buphedrone [2-(methylamino)-1-phenylbutan-1-one, α-methylamino-butyrophenone] and its effects on the mesolimbic dopaminergic system in mice using conditioned place preference (CPP) analysis, a self-administration test, a locomotor activity test, a behavioral sensitization test and Western blot analysis. Treatment with buphedrone supported CPP and self-administration, enhanced locomotor activity and produced behavioral sensitization when mice were challenged with methamphetamine. SCH23390, a D1 dopamine antagonist, prevented buphedrone-induced CPP, whereas raclopride, a D2 dopamine antagonist, had no effect. SCH23390 also blocked locomotor activity increase by buphedrone, while raclopride partially attenuated locomotor activation. Western blot analysis revealed that repeated buphedrone treatment increased D1 dopamine receptor expression in the dorsal striatum and nucleus accumbens in mice. Collectively, these findings suggest the abuse potential of buphedrone and demonstrate the involvement of the dopaminergic system in the establishment of its rewarding properties.
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Affiliation(s)
- Ji-Hwan Oh
- Department of Pharmacology, School of Pharmacy; Sungkyunkwan University; Korea
| | - Ji-Young Hwang
- Department of Pharmacology, School of Pharmacy; Sungkyunkwan University; Korea
| | - Sa-Ik Hong
- Department of Pharmacology, School of Pharmacy; Sungkyunkwan University; Korea
| | - Shi-Xun Ma
- Department of Pharmacology, School of Pharmacy; Sungkyunkwan University; Korea
| | - Jee-Yeon Seo
- Department of Pharmacology, School of Pharmacy; Sungkyunkwan University; Korea
| | - Seok-Yong Lee
- Department of Pharmacology, School of Pharmacy; Sungkyunkwan University; Korea
| | - Hyoung-Chun Kim
- Neurotoxicology Program, College of Pharmacy, Korea Institute of Drug Abuse; Kangwon National University; Korea
| | - Choon-Gon Jang
- Department of Pharmacology, School of Pharmacy; Sungkyunkwan University; Korea
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30
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Dendrosomal nanocurcumin prevents morphine self-administration behavior in rats despite CA1 damage. Behav Pharmacol 2017; 28:681-689. [DOI: 10.1097/fbp.0000000000000291] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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31
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Neurocognitive dysfunction following repeated binge-like self-administration of the synthetic cathinone 3,4-methylenedioxypyrovalerone (MDPV). Neuropharmacology 2017; 134:36-45. [PMID: 29183686 DOI: 10.1016/j.neuropharm.2017.11.034] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 10/10/2017] [Accepted: 11/21/2017] [Indexed: 01/08/2023]
Abstract
Synthetic cathinones, frequently referred to as "bath salts", have significant abuse potential, and recent evidence suggests that these novel psychoactive substances can also produce cognitive deficits as well as cytotoxic effects. However, most of these latter findings have been obtained either using high concentrations in vitro or following non-contingent high dose administration in vivo. The present study utilized a model of long-term voluntary binge-like self-administration to determine potential detrimental effects of synthetic cathinones on cognitive function and their known underlying neural circuits, collectively referred to as neurocognitive dysfunction. Male Sprague-Dawley rats were allowed to self-administer the cocaine-like synthetic cathinone 3,4-methylenedioxypyrovalerone (MDPV, 0.03 mg/kg/infusion i.v.) in 96-hr sessions, or saline as a control. A total of five 96-hr sessions were conducted, each separated by 3 days of abstinence in the home cage. Three weeks following the last 96-hr session, animals underwent assessment of cognitive function using spatial object recognition (SOR) and novel object recognition (NOR) tasks, after which brains were harvested and assessed for neurodegeneration using FluoroJade C (FJC). Compared to animals self-administering saline, animals self-administering MDPV demonstrated (1) robust drug intake that escalated over time, (2) deficits in NOR but not SOR, and (3) neurodegeneration in the perirhinal and entorhinal cortices. These results indicate that repeated binge-like intake of MDPV can induce neurocognitive dysfunction. In addition, utilization of rodent models of extended binge-like intake may provide insight into potential mechanisms and/or approaches to prevent or reverse the detrimental effects of abused substances on cognitive and neurobiological functioning. This article is part of the Special Issue entitled 'Designer Drugs and Legal Highs.'
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32
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Dingess PM, Darling RA, Derman RC, Wulff SS, Hunter ML, Ferrario CR, Brown TE. Structural and Functional Plasticity within the Nucleus Accumbens and Prefrontal Cortex Associated with Time-Dependent Increases in Food Cue-Seeking Behavior. Neuropsychopharmacology 2017; 42:2354-2364. [PMID: 28294131 PMCID: PMC5645745 DOI: 10.1038/npp.2017.57] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Revised: 03/08/2017] [Accepted: 03/09/2017] [Indexed: 01/18/2023]
Abstract
Urges to consume food can be driven by stimuli in the environment that are associated with previous food experience. Identifying adaptations within brain reward circuits that facilitate cue-induced food seeking is critical for understanding and preventing the overconsumption of food and subsequent weight gain. Utilizing electrophysiological, biochemical, and DiI labeling, we examined functional and structural changes in the nucleus accumbens (NAc) and prefrontal cortex (PFC) associated with time-dependent increases in food craving ('incubation of craving'). Rats self-administered 60% high fat or chow 45 mg pellets and were then tested for incubation of craving either 1 or 30 days after training. High fat was chosen for comparison to determine whether palatability differentially affected incubation and/or plasticity. Rats showed robust incubation of craving for both food rewards, although responding for cues previously associated with high fat was greater than chow at both 1 and 30 days. In addition, previous experience with high-fat consumption reduced dendritic spine density in the PFC at both time points. In contrast, incubation was associated with an increase in NAc spine density and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR)-mediated transmission at 30 days in both groups. Finally, incubation of craving for chow and high fat was accompanied by an increase in calcium-permeable and calcium-impermeable AMPARs, respectively. Our results suggest that incubation of food craving alters brain reward circuitry and macronutrient composition specifically induces cortical changes in a way that may facilitate maladaptive food-seeking behaviors.
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Affiliation(s)
- Paige M Dingess
- Neuroscience Program, University of Wyoming, Laramie, WY, USA
| | | | - Rifka C Derman
- Neuroscience Program, University of Michigan, Ann Arbor, MI, USA
| | - Shaun S Wulff
- Department of Statistics, University of Wyoming, Laramie, WY, USA
| | | | - Carrie R Ferrario
- Neuroscience Program, University of Michigan, Ann Arbor, MI, USA,Department of Pharmacology, University of Michigan, Ann Arbor, MI, USA
| | - Travis E Brown
- Neuroscience Program, University of Wyoming, Laramie, WY, USA,Department of Statistics, University of Wyoming, Laramie, WY, USA,School of Pharmacy, Neuroscience Program, University of Wyoming, 1000 E. University Avenue, Department 3375, Laramie, WY 82071, USA, Tel: 307 766 6129, Fax: 307 766 2953, E-mail:
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Leonard MZ, DeBold JF, Miczek KA. Escalated cocaine "binges" in rats: enduring effects of social defeat stress or intra-VTA CRF. Psychopharmacology (Berl) 2017; 234:2823-2836. [PMID: 28725939 PMCID: PMC5709163 DOI: 10.1007/s00213-017-4677-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Accepted: 06/16/2017] [Indexed: 12/16/2022]
Abstract
RATIONALE Exposure to intermittent social defeat stress elicits corticotropin releasing factor (CRF) release into the VTA and induces long-term modulation of mesocorticolimbic dopamine activity in rats. These adaptations are associated with an intense cocaine-taking phenotype, which is prevented by CRF receptor antagonists. OBJECTIVE The present studies examine whether infusion of CRF into the VTA is sufficient to escalate cocaine-taking behavior, in the absence of social defeat experience. Additionally, we aimed to characterize changes in cocaine valuation that may promote binge-like cocaine intake. METHODS Male Long-Evans rats were microinjected into the VTA with CRF (50 or 500 ng/side), vehicle, or subjected to social defeat stress, intermittently over 10 days. Animals were then trained to self-administer IV cocaine (FR5). Economic demand for cocaine was evaluated using a within-session behavioral-economics threshold procedure, which was followed by a 24-h extended access "binge." RESULTS Rats that experienced social defeat or received intra-VTA CRF microinfusions (50 ng) both took significantly more cocaine than controls over the 24-h binge but showed distinct patterns of intake. Behavioral economic analysis revealed that individual demand for cocaine strongly predicts binge-like consumption, and demand elasticity (i.e. α) is augmented by intra-VTA CRF, but not by social defeat. The effects of CRF on cocaine-taking were also prevented by intra-VTA pretreatment with CP376395, but not Astressin-2B. CONCLUSIONS Repeated infusion of CRF into the VTA persistently alters cocaine valuation and intensifies binge-like drug intake in a CRF-R1-dependent manner. Conversely, the persistent pattern of cocaine bingeing induced by social defeat stress may suggest impaired inhibitory control, independent of reward valuation.
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Affiliation(s)
| | - Joseph F DeBold
- Department of Psychology, Tufts University, Medford, MA, USA
| | - Klaus A Miczek
- Department of Psychology, Tufts University, Medford, MA, USA.
- Department of Neuroscience, Tufts University, Boston, MA, USA.
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Systemic Delivery of a Brain-Penetrant TrkB Antagonist Reduces Cocaine Self-Administration and Normalizes TrkB Signaling in the Nucleus Accumbens and Prefrontal Cortex. J Neurosci 2017; 36:8149-59. [PMID: 27488635 DOI: 10.1523/jneurosci.2711-14.2016] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Accepted: 06/10/2016] [Indexed: 12/17/2022] Open
Abstract
UNLABELLED Cocaine exposure alters brain-derived neurotrophic factor (BDNF) expression in the brain. BDNF signaling through TrkB receptors differentially modulates cocaine self-administration, depending on the brain regions involved. In the present study, we determined how brain-wide inhibition of TrkB signaling affects cocaine intake, the motivation for the drug, and reinstatement of drug taking after extinction. To overcome the inability of TrkB ligands to cross the blood-brain barrier, the TrkB antagonist cyclotraxin-B was fused to the nontoxic transduction domain of the tat protein from human immunodeficiency virus type 1 (tat-cyclotraxin-B). Intravenous injection of tat-cyclotraxin-B dose-dependently reduced cocaine intake, motivation for cocaine (as measured under a progressive ratio schedule of reinforcement), and reinstatement of cocaine taking in rats allowed either short or long access to cocaine self-administration. In contrast, the treatment did not affect operant responding for a highly palatable sweet solution, demonstrating that the effects of tat-cyclotraxin-B are specific for cocaine reinforcement. Cocaine self-administration increased TrkB signaling and activated the downstream Akt pathway in the nucleus accumbens, and had opposite effects in the prefrontal cortex. Pretreatment with tat-cyclotraxin-B normalized protein levels in these two dopamine-innervated brain regions. Cocaine self-administration also increased TrkB signaling in the ventral tegmental area, where the dopaminergic projections originate, but pretreatment with tat-cyclotraxin-B did not alter this effect. Altogether, our data show that systemic administration of a brain-penetrant TrkB antagonist leads to brain region-specific effects and may be a potential pharmacological strategy for the treatment of cocaine addiction. SIGNIFICANCE STATEMENT Brain-derived neurotrophic factor (BDNF) signaling through TrkB receptors plays a well established role in cocaine reinforcement. However, local manipulation of BDNF signaling yields divergent effects, depending on the brain region, thereby questioning the viability of systemic TrkB targeting for the treatment of cocaine use disorders. Our study provides first-time evidence that systemic administration of a brain-penetrant TrkB antagonist (tat-cyclotraxin-B) reduces several behavioral measures of cocaine dependence, without altering motor performance or reinforcement by a sweet palatable solution. In addition, although cocaine self-administration produced opposite effects on TrkB signaling in the nucleus accumbens and prefrontal cortex, tat-cyclotraxin-B administration normalized these cocaine-induced changes in both brain regions.
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Schmeichel BE, Herman MA, Roberto M, Koob GF. Hypocretin Neurotransmission Within the Central Amygdala Mediates Escalated Cocaine Self-administration and Stress-Induced Reinstatement in Rats. Biol Psychiatry 2017; 81:606-615. [PMID: 27567312 PMCID: PMC5161745 DOI: 10.1016/j.biopsych.2016.06.010] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Revised: 06/06/2016] [Accepted: 07/07/2016] [Indexed: 12/29/2022]
Abstract
BACKGROUND Cocaine addiction is characterized by patterns of compulsive drug-taking, including preoccupation with obtaining cocaine and loss of control over drug intake. The lateral hypothalamic hypocretin/orexin (HCRT) system has been implicated in drug-taking and the reinstatement of drug-seeking. Evidence suggests that HCRT may drive drug-seeking through activation of specific brain regions implicated in stress system dysfunction, including the central amygdala (CeA). The role of HCRT in the persistence of compulsive-like cocaine-taking has yet to be fully elucidated. METHODS Systemic and intra-CeA microinfusions of the HCRT-receptor 1 antagonist, SB-334867, were administered to rats allowed either short (1 hour; ShA) or long (6 hours; LgA) access to cocaine self-administration. Animals were tested for fixed and progressive ratio responding for cocaine and stress-induced reinstatement of drug-seeking. In addition, using electrophysiological techniques on in vitro slices, we investigated gamma-aminobutyric acidergic (GABAergic) neurotransmission in the medial CeA and the sensitivity of GABAergic synapses to modulation of the HCRT system in ShA or LgA rats. RESULTS We found systemic administration of SB-334867 (0, 7.5, 15, 30 mg/kg) dose dependently decreased cocaine intake specifically in LgA rats but not in ShA rats. Microinjections of SB-334867 (20 nmol) bilaterally into the CeA significantly reduced cocaine intake in LgA rats. We also observed a significant attenuation of yohimbine-induced reinstatement of cocaine-seeking after intra-CeA SB-334867 (10 nmol) administration. Finally, electrophysiological data indicated enhanced GABAergic neurotransmission within the medial CeA in LgA rats, which was blocked with SB-334867 (10 μmol/L). CONCLUSIONS These findings suggest that HCRT neurotransmission within the CeA is implicated in compulsive-like cocaine-seeking.
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Affiliation(s)
- Brooke E. Schmeichel
- Neurobiology of Addiction Section, Integrative Neuroscience Research Branch, National Institute on Drug Abuse, Baltimore, Maryland 21224,Corresponding author: Dr. Brooke E. Schmeichel, National Institute on Drug Abuse, 251 Bayview Boulevard, Baltimore, Maryland 21224, Phone +1 443-740-2562 Fax +1 443-740-2827,
| | - Melissa A. Herman
- Committee on the Neurobiology of Addictive Disorders, The Scripps Research Institute, La Jolla, CA, 92037
| | - Marisa Roberto
- Committee on the Neurobiology of Addictive Disorders, The Scripps Research Institute, La Jolla, CA, 92037
| | - George F. Koob
- Neurobiology of Addiction Section, Integrative Neuroscience Research Branch, National Institute on Drug Abuse, Baltimore, Maryland 21224,National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD 20892
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Brodnik ZD, Ferris MJ, Jones SR, España RA. Reinforcing Doses of Intravenous Cocaine Produce Only Modest Dopamine Uptake Inhibition. ACS Chem Neurosci 2017; 8:281-289. [PMID: 27936579 DOI: 10.1021/acschemneuro.6b00304] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
The reinforcing efficacy of cocaine is thought to stem from inhibition of the dopamine transporter (DAT) and subsequent increases in extracellular dopamine concentrations in the brain. In humans, this hypothesis has generally been supported by positron emission tomography imaging studies where the percent of DATs occupied by cocaine is used as a measure of cocaine activity in the brain. Interpretation of these studies, however, often relies on the assumption that measures of DAT occupancy directly correspond with functional DAT blockade. In the current studies, we used in vivo and in vitro fast scan cyclic voltammetry in mice to measure dopamine uptake inhibition following varying doses of cocaine as well as two high affinity DAT inhibitors. We then compared dopamine clearance rates following these drug treatments to dopamine clearance obtained from DAT knockout mice as a proxy for complete DAT blockade. We found that administration of abused doses of cocaine resulted in approximately 2% of maximal DAT blockade. Overall, our data indicate that abused doses of cocaine produce a relatively modest degree of DA uptake inhibition, and suggest that the relationship between DAT occupancy and functional blockade of the DAT is more complex than originally posited.
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Affiliation(s)
- Zachary D. Brodnik
- Department
of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, Pennsylvania 19129, United States
| | - Mark J. Ferris
- Department
of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, North Carolina 27501, United States
| | - Sara R. Jones
- Department
of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, North Carolina 27501, United States
| | - Rodrigo A. España
- Department
of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, Pennsylvania 19129, United States
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Bidirectional regulation over the development and expression of loss of control over cocaine intake by the anterior insula. Psychopharmacology (Berl) 2017; 234:1623-1631. [PMID: 28378203 PMCID: PMC5420385 DOI: 10.1007/s00213-017-4593-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Accepted: 03/08/2017] [Indexed: 02/03/2023]
Abstract
RATIONALE Increasing evidence suggests that the anterior insular cortex (AIC) plays a major role in cocaine addiction, being implicated in both impaired insight and associated decision-making and also craving and relapse. However, the nature of the involvement of the insula in the development and maintenance of cocaine addiction remains unknown, thereby limiting our understanding of its causal role in addiction. We therefore investigated whether pre- and post-training bilateral lesions of the AIC differentially influenced the development and the expression of the escalation of cocaine self-administration during extended access to the drug. METHODS In a series of experiments, Sprague Dawley rats received bilateral excitotoxic lesions of the AIC either prior to, or after 3 weeks of training under 12-h extended self-administration conditions, which are known to promote a robust escalation of intake. We also investigated the influence of AIC lesions on anxiety, as measured in an elevated plus maze and sensitivity to conditioned stimuli (CS)- or drug-induced reinstatement of an extinguished instrumental response. RESULTS Whereas, post-escalation lesions of the AIC, as anticipated, restored control over cocaine intake and prevented drug-induced reinstatement, pre-training lesions resulted in a facilitation of the development of loss of control with no influence over the acquisition of cocaine self-administration or anxiety. CONCLUSIONS AIC lesions differentially affect the development and maintenance of the loss of control over cocaine intake, suggesting that the nature of the contribution of cocaine-associated interoceptive mechanisms changes over the course of escalation and may represent an important component of addiction.
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Estradiol Facilitation of Cocaine Self-Administration in Female Rats Requires Activation of mGluR5. eNeuro 2016; 3:eN-NWR-0140-16. [PMID: 27822496 PMCID: PMC5079229 DOI: 10.1523/eneuro.0140-16.2016] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Revised: 10/07/2016] [Accepted: 10/07/2016] [Indexed: 02/06/2023] Open
Abstract
In comparison to men, women initiate drug use at earlier ages and progress from initial use to addiction more rapidly. This heightened intake and vulnerability to drugs of abuse is regulated in part by estradiol, although the signaling mechanisms by which this occurs are not well understood. Recent findings indicate that within the nucleus accumbens core, estradiol induces structural plasticity via membrane-localized estrogen receptor α, functionally coupled to metabotropic glutamate receptor subtype 5 (mGluR5). Hence, we sought to determine whether mGluR5 activation was essential for estradiol-mediated enhancement of cocaine self-administration. Ovariectomized (OVX) female rats were allowed to freely self-administer cocaine under extended access conditions (6 h/d) for 10 consecutive days. The mGluR5 antagonist 2-methyl-6-(phenylethynyl)pyridine hydrochloride (MPEP) or vehicle was administered before estradiol (or oil), on a 2 d on/2 d off schedule throughout the extended access period. MPEP treatment prevented the estradiol-dependent enhancement of cocaine self-administration in OVX females. In a separate experiment, potentiation of mGluR5 function with the positive allosteric modulator 3-cyano-N-(1,3-diphenyl-1H-pyrazol-5-yl)benzamide (in the absence of estradiol treatment) failed to increase cocaine self-administration. These data suggest that mGluR5 activation is necessary for estradiol-mediated enhancement of responses to cocaine, but that direct mGluR5 activation is insufficient to mimic the female response to estradiol. Building on previous studies in male animals, these findings further highlight the therapeutic potential of mGluR5 antagonism in the treatment of addiction and suggest that there may be added therapeutic benefit in females.
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You IJ, Wright SR, Garcia-Garcia AL, Tapper AR, Gardner PD, Koob GF, David Leonardo E, Bohn LM, Wee S. 5-HT1A Autoreceptors in the Dorsal Raphe Nucleus Convey Vulnerability to Compulsive Cocaine Seeking. Neuropsychopharmacology 2016; 41:1210-22. [PMID: 26324408 PMCID: PMC4793105 DOI: 10.1038/npp.2015.268] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Revised: 08/02/2015] [Accepted: 08/11/2015] [Indexed: 11/09/2022]
Abstract
Cocaine addiction and depression are comorbid disorders. Although it is well recognized that 5-hydroxytryptamine (5-HT; serotonin) plays a central role in depression, our understanding of its role in addiction is notably lacking. The 5-HT system in the brain is carefully controlled by a combined process of regulating 5-HT neuron firing through 5-HT autoreceptors, neurotransmitter release, enzymatic degradation, and reuptake by transporters. This study tests the hypothesis that activation of 5-HT1A autoreceptors, which would lessen 5-HT neuron firing, contributes to cocaine-seeking behaviors. Using 5-HT neuron-specific reduction of 5-HT1A autoreceptor gene expression in mice, we demonstrate that 5-HT1A autoreceptors are necessary for cocaine conditioned place preference. In addition, using designer receptors exclusively activated by designer drugs (DREADDs) technology, we found that stimulation of the serotonergic dorsal raphe nucleus (DRN) afferents to the nucleus accumbens (NAc) abolishes cocaine reward and promotes antidepressive-like behaviors. Finally, using a rat model of compulsive-like cocaine self-administration, we found that inhibition of dorsal raphe 5-HT1A autoreceptors attenuates cocaine self-administration in rats with 6 h extended access, but not 1 h access to the drug. Therefore, our findings suggest an important role for 5-HT1A autoreceptors, and thus DRNNAc 5-HT neuronal activity, in the etiology and vulnerability to cocaine reward and addiction. Moreover, our findings support a strategy for antagonizing 5-HT1A autoreceptors for treating cocaine addiction.
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Affiliation(s)
- In-Jee You
- Department of Psychiatry, Brudnick Neuropsychiatric Research Institute, University of Massachusetts Medical School, Worcester, MA, USA,Department of Molecular Therapeutics, The Scripps Research Institute-Florida, Jupiter, FL, USA,Department of Psychiatry, Brudnick Neuropsychiatric Research Institute, University of Massachusetts Medical School, Worcester, MA 01604, USA, Tel: +1 508 455 4293, Fax: +1 508 455 4281, E-mail:
| | - Sherie R Wright
- Department of Molecular Therapeutics, The Scripps Research Institute-Florida, Jupiter, FL, USA
| | | | - Andrew R Tapper
- Department of Psychiatry, Brudnick Neuropsychiatric Research Institute, University of Massachusetts Medical School, Worcester, MA, USA
| | - Paul D Gardner
- Department of Psychiatry, Brudnick Neuropsychiatric Research Institute, University of Massachusetts Medical School, Worcester, MA, USA
| | - George F Koob
- Committee on the Neurobiology of Addictive Disorders, The Scripps Research Institute, La Jolla, CA, USA,National Institute on Alcohol Abuse and Alcoholism, Rockville, MD, USA
| | - E David Leonardo
- Department of Psychiatry, Columbia University, New York, NY, USA,New York State Psychiatric Institute, New York, NY, USA
| | - Laura M Bohn
- Department of Molecular Therapeutics, The Scripps Research Institute-Florida, Jupiter, FL, USA
| | - Sunmee Wee
- Department of Molecular Therapeutics, The Scripps Research Institute-Florida, Jupiter, FL, USA
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Batra V, Guerin GF, Goeders NE, Wilden JA. A General Method for Evaluating Deep Brain Stimulation Effects on Intravenous Methamphetamine Self-Administration. J Vis Exp 2016:e53266. [PMID: 26863392 PMCID: PMC4781683 DOI: 10.3791/53266] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Substance use disorders, particularly to methamphetamine, are devastating, relapsing diseases that disproportionally affect young people. There is a need for novel, effective and practical treatment strategies that are validated in animal models. Neuromodulation, including deep brain stimulation (DBS) therapy, refers to the use of electricity to influence pathological neuronal activity and has shown promise for psychiatric disorders, including drug dependence. DBS in clinical practice involves the continuous delivery of stimulation into brain structures using an implantable pacemaker-like system that is programmed externally by a physician to alleviate symptoms. This treatment will be limited in methamphetamine users due to challenging psychosocial situations. Electrical treatments that can be delivered intermittently, non-invasively and remotely from the drug-use setting will be more realistic. This article describes the delivery of intracranial electrical stimulation that is temporally and spatially separate from the drug-use environment for the treatment of IV methamphetamine dependence. Methamphetamine dependence is rapidly developed in rodents using an operant paradigm of intravenous (IV) self-administration that incorporates a period of extended access to drug and demonstrates both escalation of use and high motivation to obtain drug.
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Affiliation(s)
- Vinita Batra
- Department of Neurosurgery, Louisiana State University
| | - Glenn F Guerin
- Department of Pharmacology, Toxicology, and Neuroscience, Louisiana State University
| | - Nicholas E Goeders
- Department of Pharmacology, Toxicology, and Neuroscience, Louisiana State University
| | - Jessica A Wilden
- Department of Neurosurgery, Louisiana State University; Department of Pharmacology, Toxicology, and Neuroscience, Louisiana State University;
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Eagle AL, Singh R, Kohler RJ, Friedman AL, Liebowitz CP, Galloway MP, Enman NM, Jutkiewicz EM, Perrine SA. Single prolonged stress effects on sensitization to cocaine and cocaine self-administration in rats. Behav Brain Res 2015; 284:218-24. [PMID: 25712697 PMCID: PMC5370568 DOI: 10.1016/j.bbr.2015.02.027] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Revised: 02/10/2015] [Accepted: 02/13/2015] [Indexed: 12/24/2022]
Abstract
Posttraumatic stress disorder (PTSD) is often comorbid with substance use disorders (SUD). Single prolonged stress (SPS) is a well-validated rat model of PTSD that provides a framework to investigate drug-induced behaviors as a preclinical model of the comorbidity. We hypothesized that cocaine sensitization and self-administration would be increased following exposure to SPS. Male Sprague-Dawley rats were exposed to SPS or control treatment. After SPS, cocaine (0, 10 or 20 mg/kg, i.p.) was administered for 5 consecutive days and locomotor activity was measured. Another cohort was assessed for cocaine self-administration (0.1 or 0.32 mg/kg/i.v.) after SPS. Rats were tested for acquisition, extinction and cue-induced reinstatement behaviors. Control animals showed a dose-dependent increase in cocaine-induced locomotor activity after acute cocaine whereas SPS rats did not. Using a sub-threshold sensitization paradigm, control rats did not exhibit enhanced locomotor activity at Day 5 and therefore did not develop behavioral sensitization, as expected. However, compared to control rats on Day 5 the locomotor response to 20mg/kg repeated cocaine was greatly enhanced in SPS-treated rats, which exhibited enhanced cocaine locomotor sensitization. The effect of SPS on locomotor activity was unique in that SPS did not modify cocaine self-administration behaviors under a simple schedule of reinforcement. These data show that SPS differentially affects cocaine-mediated behaviors causing no effect to cocaine self-administration, under a simple schedule of reinforcement, but significantly augmenting cocaine locomotor sensitization. These results suggest that SPS shares common neurocircuitry with stimulant-induced plasticity, but dissociable from that underlying psychostimulant-induced reinforcement.
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MESH Headings
- Akathisia, Drug-Induced/physiopathology
- Animals
- Catheters, Indwelling
- Cocaine/administration & dosage
- Cocaine-Related Disorders/physiopathology
- Cohort Studies
- Conditioning, Operant/drug effects
- Conditioning, Operant/physiology
- Disease Models, Animal
- Dopamine Uptake Inhibitors/administration & dosage
- Dose-Response Relationship, Drug
- Extinction, Psychological/drug effects
- Extinction, Psychological/physiology
- Male
- Rats, Sprague-Dawley
- Self Administration
- Stress, Psychological/physiopathology
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Affiliation(s)
- Andrew L Eagle
- Department of Psychiatry and Behavioral Neuroscience, Wayne State University School of Medicine, Detroit, MI, USA
| | - Robby Singh
- Department of Psychiatry and Behavioral Neuroscience, Wayne State University School of Medicine, Detroit, MI, USA
| | - Robert J Kohler
- Department of Psychiatry and Behavioral Neuroscience, Wayne State University School of Medicine, Detroit, MI, USA
| | - Amy L Friedman
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Chelsea P Liebowitz
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Matthew P Galloway
- Department of Psychiatry and Behavioral Neuroscience, Wayne State University School of Medicine, Detroit, MI, USA; Department of Anesthesiology, Wayne State University School of Medicine, Detroit, MI, USA
| | - Nicole M Enman
- Department of Pharmacology, Temple University School of Medicine, Philadelphia, PA, USA
| | - Emily M Jutkiewicz
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Shane A Perrine
- Department of Psychiatry and Behavioral Neuroscience, Wayne State University School of Medicine, Detroit, MI, USA.
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A subpopulation of neurochemically-identified ventral tegmental area dopamine neurons is excited by intravenous cocaine. J Neurosci 2015; 35:1965-78. [PMID: 25653355 DOI: 10.1523/jneurosci.3422-13.2015] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Systemic administration of cocaine is thought to decrease the firing rates of ventral tegmental area (VTA) dopamine (DA) neurons. However, this view is based on categorizations of recorded neurons as DA neurons using preselected electrophysiological characteristics lacking neurochemical confirmation. Without applying cellular preselection, we recorded the impulse activity of VTA neurons in response to cocaine administration in anesthetized adult rats. The phenotype of recorded neurons was determined by their juxtacellular labeling and immunohistochemical detection of tyrosine hydroxylase (TH), a DA marker. We found that intravenous cocaine altered firing rates in the majority of recorded VTA neurons. Within the cocaine-responsive neurons, half of the population was excited and the other half was inhibited. Both populations had similar discharge rates and firing regularities, and most neurons did not exhibit changes in burst firing. Inhibited neurons were more abundant in the posterior VTA, whereas excited neurons were distributed evenly throughout the VTA. Cocaine-excited neurons were more likely to be excited by footshock. Within the subpopulation of TH-positive neurons, 36% were excited by cocaine and 64% were inhibited. Within the subpopulation of TH-negative neurons, 44% were excited and 28% were inhibited. Contrary to the prevailing view that all DA neurons are inhibited by cocaine, we found a subset of confirmed VTA DA neurons that is excited by systemic administration of cocaine. We provide evidence indicating that DA neurons are heterogeneous in their response to cocaine and that VTA non-DA neurons play an active role in processing systemic cocaine.
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Shen F, Duan Y, Jin S, Sui N. Varied behavioral responses induced by morphine in the tree shrew: a possible model for human opiate addiction. Front Behav Neurosci 2014; 8:333. [PMID: 25294994 PMCID: PMC4171994 DOI: 10.3389/fnbeh.2014.00333] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Accepted: 09/05/2014] [Indexed: 01/27/2023] Open
Abstract
Tree shrews represent a suitable animal model to study the pathogenesis of human diseases as they are phylogenetically close to primates and have a well-developed central nervous system that possesses many homologies with primates. Therefore, in our study, we investigated whether tree shrews can be used to explore the addictive behaviors induced by morphine. Firstly, to investigate the psychoactive effect of morphine on tree shrews’ behavior, the number of jumping and shuttling, which represent the vertical and horizontal locomotor activity respectively, was examined following the injection of different dosage of morphine. Our results showed intramuscular (IM) injection of morphine (5 or 10 mg/kg) significantly increased the locomotor activity of tree shrews 30–60 min post-injection. Then, using the conditioned place preference/aversion (CPP/CPA) paradigm, we found morphine-conditioned tree shrews exhibited place preference in the morphine-paired chamber on the test day. In addition, naloxone-precipitated withdrawal induced place aversion in the chronic morphine-dependent tree shrews. We evaluated the craving for morphine drinking by assessing the break point that reflects the maximum effort animals will expend to get the drug. Our data showed the break point was significantly increased when compared to the baseline on the 1st, 7th and 14th day after the abstinence. Moreover, in the intravenous morphine self-administration experiment, tree shrews conditioned with morphine responded on the active lever significantly more frequently than on the inactive lever after training. These results suggest that tree shrew may be a potential candidate for study the addictive behaviors and the underling neurological mechanisms.
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Affiliation(s)
- Fang Shen
- Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences Beijing, China
| | - Ying Duan
- Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences Beijing, China ; Institute of Psychology, University of Chinese Academy of Sciences Beijing, China
| | - Shubo Jin
- Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences Beijing, China ; Institute of Psychology, University of Chinese Academy of Sciences Beijing, China
| | - Nan Sui
- Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences Beijing, China
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Waters RP, Moorman DE, Young AB, Feltenstein MW, See RE. Assessment of a proposed "three-criteria" cocaine addiction model for use in reinstatement studies with rats. Psychopharmacology (Berl) 2014; 231:3197-205. [PMID: 24615055 DOI: 10.1007/s00213-014-3497-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2013] [Accepted: 02/07/2014] [Indexed: 01/08/2023]
Abstract
RATIONALE Relapse is a primary obstacle in the treatment of addiction disorders, and as such, understanding this phenomenon is a major effort of clinical and preclinical studies of cocaine addiction. OBJECTIVE A recently developed protocol uses laboratory rats to model cocaine addiction by examining three criteria of addiction-like behaviors (persistent seeking in the absence of drug, high motivation for drug, and resistance to punishment during drug seeking) to detect subjects that possess an addiction phenotype. We closely followed this protocol in order to detect rats possessing this addiction phenotype, with the goal of utilizing this model in future studies investigating potential therapies for relapse in human cocaine addicts. RESULTS The majority of the rats used in this study exhibited multiple characteristics thought to be associated with addiction-like behavior in rats, including robust reinstatement to multiple stimuli and high motivation to obtain cocaine. However, no rats displayed the complete addiction phenotype as previously described, due to a complete lack of addiction-like behavior in all subjects on two of the three addiction criteria (drug seeking in the absence of drug and resistance to punishment). CONCLUSIONS Our data highlight the independence of behavioral aspects of a rat addiction-like phenotype and suggest that some of these behavioral criteria may be altogether absent in some rat populations. Furthermore, our results suggest a closer review and analysis of some parameters used in this protocol and its global utility.
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Affiliation(s)
- R Parrish Waters
- NeuroCure Cluster of Excellence, Charité Universitätsmedizin, Charité Platz 1, 10117, Berlin, Germany,
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45
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Woller SA, Malik JS, Aceves M, Hook MA. Morphine self-administration following spinal cord injury. J Neurotrauma 2014; 31:1570-83. [PMID: 24827476 DOI: 10.1089/neu.2013.3293] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Neuropathic pain develops in up to two-thirds of people following spinal cord injury (SCI). Opioids are among the most effective treatments for this pain and are commonly prescribed. There is concern surrounding the use of these analgesics, however, because use is often associated with the development of addiction. Previous data suggests that this concern may not be relevant in the presence of neuropathic pain. Yet, despite the common prescription of opioids for the treatment of SCI-related pain, there has been only one previous study examining the addictive potential of morphine following spinal injury. To address this, the present study used a self-administration paradigm to examine the addictive potential of morphine in a rodent model of SCI. Animals were placed into self-administration chambers 24 h, 14 d, or 35 d following a moderate spinal contusion injury. They were placed into the chambers for seven 12-hour sessions with access to 1.5 mg morphine/lever depression (up to 30 mg/d). In the acute phase of SCI, contused animals self-administered significantly less morphine than their sham counterparts, as previously shown. However, contused animals showing signs of neuropathic pain did not self-administer less morphine than their sham counterparts when administration began 14 or 35 d after injury. Instead, these animals administered nearly the full amount of morphine available each session. This amount of morphine did not affect recovery of locomotor function but did cause significant weight loss. We suggest caution is warranted when prescribing opioids for the treatment of neuropathic pain resulting from SCI, as the addictive potential is not reduced in this model.
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Affiliation(s)
- Sarah A Woller
- 1 Texas A&M University Institute for Neuroscience , Texas A&M Health Science Center, Bryan, Texas
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West EA, Saddoris MP, Kerfoot EC, Carelli RM. Prelimbic and infralimbic cortical regions differentially encode cocaine-associated stimuli and cocaine-seeking before and following abstinence. Eur J Neurosci 2014; 39:1891-902. [PMID: 24690012 PMCID: PMC4260329 DOI: 10.1111/ejn.12578] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2013] [Revised: 02/21/2014] [Accepted: 03/03/2014] [Indexed: 01/12/2023]
Abstract
Cocaine stimuli often trigger relapse of drug-taking, even following periods of prolonged abstinence. Here, electrophysiological recordings were made in rats (n = 29) to determine how neurons in the prelimbic (PrL) or infralimbic (IL) regions of the medial prefrontal cortex (mPFC) encode cocaine-associated stimuli and cocaine-seeking, and whether this processing is differentially altered after 1 month of cocaine abstinence. After self-administration training, neurons (n = 308) in the mPFC were recorded during a single test session conducted either the next day or 1 month later. Test sessions consisted of three phases during which (i) the tone-houselight stimulus previously paired with cocaine infusion during self-administration was randomly presented by the experimenter, (ii) rats responded on the lever previously associated with cocaine during extinction and (iii) the tone-houselight was presented randomly between cocaine-reinforced responding during resumption of cocaine self-administration. PrL neurons showed enhanced encoding of the cocaine stimulus and drug-seeking behavior (under extinction and self-administration) following 30 days of abstinence. In contrast, although IL neurons encoded cocaine cues and cocaine-seeking, there were no pronounced changes in IL responsiveness following 30 days of abstinence. Importantly, cue-related changes do not represent a generalised stimulus-evoked discharge as PrL and IL neurons in control animals (n = 4) exhibited negligible recruitment by the tone-houselight stimulus. The results support the view that, following abstinence, neural encoding in the PrL but not IL may play a key role in enhanced cocaine-seeking, particularly following re-exposure to cocaine-associated cues.
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Affiliation(s)
- Elizabeth A. West
- Department of Psychology, University of North Carolina, Chapel Hill, Chapel Hill, NC 27599
| | - Michael P. Saddoris
- Department of Psychology, University of North Carolina, Chapel Hill, Chapel Hill, NC 27599
| | - Erin C. Kerfoot
- Department of Psychology, University of North Carolina, Chapel Hill, Chapel Hill, NC 27599
| | - Regina M. Carelli
- Department of Psychology, University of North Carolina, Chapel Hill, Chapel Hill, NC 27599
- Neuroscience Center, University of North Carolina, Chapel Hill, Chapel Hill, NC 27599
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Continuous exposure to dizocilpine facilitates escalation of cocaine consumption in male Sprague-Dawley rats. Drug Alcohol Depend 2014; 134:38-43. [PMID: 24103127 PMCID: PMC3865177 DOI: 10.1016/j.drugalcdep.2013.09.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2013] [Revised: 08/09/2013] [Accepted: 09/06/2013] [Indexed: 11/20/2022]
Abstract
BACKGROUND Although the escalation of cocaine consumption is a hallmark of cocaine dependence, the neurobiological mechanisms that underlie this change in behavior are not well understood. METHODS This study used an extended access version of the drug self-administration procedure to explore how N-methyl-d-aspartate (NMDA) receptors are involved in escalation of cocaine consumption. Male Sprague-Dawley rats (n=59) were first trained to self-administer cocaine (0.33 mg/infusion, i.v.) under a fixed-ratio 1 (FR1) schedule of reinforcement. After training, rats were implanted with subcutaneous osmotic minipumps filled with vehicle or the non-competitive NMDAR antagonist, dizocilpine (0.2 or 0.4 mg/kg/d), and subsequently allowed to self-administer cocaine in 2h or 6h self-administration sessions. RESULTS In the 6h groups, vehicle-treated rats escalated cocaine self-administration across 15 self-administration sessions; rats treated with dizocilpine escalated cocaine self-administration at a greater rate and to a greater degree. Rats that self-administered cocaine during 2h sessions did not escalate consumption of cocaine under any treatment condition. Discontinuation of dizocilpine treatment in the 6h access condition led to a substantial decrease in cocaine consumption, down to pre-escalation levels, and then control rates of escalation thereafter. Despite large differences in intake under the FR1 schedule, post-escalation break point under a progressive ratio schedule of reinforcement did not differ between groups. CONCLUSION These data suggest that glutamate tone through NMDA receptors can play a dynamic role in regulating cocaine intake and escalation of consumption.
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48
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Minogianis EA, Lévesque D, Samaha AN. The speed of cocaine delivery determines the subsequent motivation to self-administer the drug. Neuropsychopharmacology 2013; 38:2644-56. [PMID: 23921953 PMCID: PMC3828535 DOI: 10.1038/npp.2013.173] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2013] [Revised: 07/11/2013] [Accepted: 07/15/2013] [Indexed: 12/17/2022]
Abstract
The rapid delivery of drugs of abuse to the brain is associated with an increased likelihood and severity of addiction. Here we evaluated the hypothesis that rapidly delivered cocaine facilitates the addiction process by promoting the development of enhanced motivation for the drug. Rats lever-pressed for cocaine delivered intravenously over 5 or 90 s under fixed ratio (FR) during 6-h sessions. The motivation for cocaine was subsequently assessed using a progressive ratio (PR) schedule, where each successive drug injection cost an exponentially greater number of lever presses, until the cessation of responding. Throughout all self-administration sessions, all rats could only take one injection every 90 s. The 5-s groups self-administered more drug than the 90-s groups across the FR sessions. Under PR, animals that had chronically self-administered rapidly delivered cocaine took more cocaine across a range of doses and regardless of whether the drug was delivered over 5 or 90 s during PR testing. The speed of delivery also determined the long-term neurobiological impact of cocaine. Fourteen days following cocaine withdrawal, caudate-putamen D2 levels were decreased only in the 90-s rats, and quinpirole-mediated Gα(i/o)-protein activation was increased to a greater extent in the 90- vs 5-s rats. Thus, rapid delivery promotes the pursuit of cocaine in the face of rising costs and alters cocaine-induced changes in striatal D2 receptor number and function. As such, rapidly delivered cocaine might facilitate addiction because it more readily alters brain motivation circuits in ways that contribute to the compulsive pursuit of the drug.
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Affiliation(s)
- Ellie-Anna Minogianis
- Department of Pharmacology, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
| | - Daniel Lévesque
- Faculty of Pharmacy, Université de Montréal, Montreal, QC, Canada,CNS Research Group, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
| | - Anne-Noël Samaha
- Department of Pharmacology, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada,CNS Research Group, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada,Department of Pharmacology, Faculty of Medicine, Université de Montréal, C.P. 6128, Succursale Centre-ville, Montreal, QC H3C 3J7, Canada, Tel: +514 343 6111 x. 32788, Fax: +514 343 2291, E-mail:
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Peer influences on drug self-administration: an econometric analysis in socially housed rats. Behav Pharmacol 2013; 24:114-23. [PMID: 23412112 DOI: 10.1097/fbp.0b013e32835f1719] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Social-learning theories of substance use propose that members of peer groups influence the drug use of other members by selectively modeling, reinforcing, and punishing either abstinence-related or drug-related behaviors. The objective of the present study was to examine the social influences on cocaine self-administration in isolated and socially housed rats, under conditions where the socially housed rats were tested simultaneously with their partner in the same chamber. To this end, male rats were obtained at weaning and housed in isolated or pair-housed conditions for 6 weeks. Rats were then implanted with intravenous catheters and cocaine self-administration was examined in custom-built operant conditioning chambers that allowed two rats to be tested simultaneously. For some socially housed subjects, both rats had simultaneous access to cocaine; for others, only one rat of the pair had access to cocaine. An econometric analysis was applied to the data, and the reinforcing strength of cocaine was measured by examining consumption (i.e. quantity demanded) and elasticity of demand as a function of price, which was manipulated by varying the dose and ratio requirements on a fixed ratio schedule of reinforcement. Cocaine consumption decreased as a function of price in all groups. Elasticity of demand did not vary across groups, but consumption was significantly lower in socially housed rats paired with a rat without access to cocaine. These data suggest that the presence of an abstaining peer decreases the reinforcing strength of cocaine, thus supporting the development of social interventions in drug abuse prevention and treatment programs.
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Lee SY, You IJ, Kim MJ, Kwon SH, Hong SI, Kim JH, Jang MH, Oh SM, Chung KH, Lee SY, Jang CG. The abuse potential of oxethazaine: Effects of oxethazaine on drug-seeking behavior and analysis of its metabolites in plasma and hair in animal models. Pharmacol Biochem Behav 2013; 105:98-104. [DOI: 10.1016/j.pbb.2013.01.022] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2012] [Revised: 01/28/2013] [Accepted: 01/31/2013] [Indexed: 10/27/2022]
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