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Algallal HE, Jacquemet V, Samaha AN. Intermittent nicotine access is as effective as continuous access in promoting nicotine seeking and taking in rats. Psychopharmacology (Berl) 2024; 241:1135-1149. [PMID: 38326505 DOI: 10.1007/s00213-024-06546-4] [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] [Received: 01/09/2024] [Accepted: 01/20/2024] [Indexed: 02/09/2024]
Abstract
RATIONALE Nicotine is a principal psychoactive agent in tobacco, contributing to tobacco's addictive potential. Preclinical studies on the effects of voluntary nicotine intake typically use self-administration procedures that provide continuous nicotine access during each self-administration session. However, many smokers consume cigarettes intermittently rather than continuously throughout each day. For drugs including cocaine and opioids, research in laboratory rats shows that intermittent intake can be more effective than continuous intake in producing patterns of drug use relevant to addiction. OBJECTIVE We determined how intermittent versus continuous nicotine self-administration influences nicotine seeking and taking behaviours. METHODS Female and male rats had continuous (i.e., Long Access; LgA, 6 h/day) or intermittent (IntA; 12 min ON, 60 min OFF, for 6 h/day) access to intravenous nicotine (15 µg/kg/infusion), for 12 daily sessions. We then assessed intake, responding for nicotine under a progressive ratio schedule of drug reinforcement and cue- and nicotine-induced reinstatement of drug seeking. We also estimated nicotine pharmacokinetic parameters during LgA and IntA self-administration. RESULTS Overall, LgA rats took twice more nicotine than did IntA rats, yielding more sustained increases in estimated brain concentrations of the drug. However, the two groups showed similar motivation to seek and take nicotine, as measured using reinstatement and progressive ratio procedures, respectively. CONCLUSIONS Intermittent nicotine use is just as effective as continuous use in producing addiction-relevant behaviours, despite significantly less nicotine exposure. This has implications for modeling nicotine self-administration patterns in human smokers and resulting effects on brain and behaviour.
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Affiliation(s)
- Hajer E Algallal
- Biomedical Sciences, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
| | - Vincent Jacquemet
- Institute of Biomedical Engineering, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
- Department of Pharmacology and Physiology, Faculty of Medicine, Université de Montréal, C.P. 6128, Succursale Centre-Ville, Montreal, QC, H3C 3J7, Canada
| | - Anne-Noël Samaha
- Department of Pharmacology and Physiology, Faculty of Medicine, Université de Montréal, C.P. 6128, Succursale Centre-Ville, Montreal, QC, H3C 3J7, Canada.
- Neural Signaling and Circuitry Research Group (SNC), Faculty of Medicine, Université de Montréal, Montreal, QC, Canada.
- Center for Interdisciplinary Research On the Brain and Learning (CIRCA), Université de Montréal, Montreal, QC, Canada.
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Ndiaye NA, Shamleh SA, Casale D, Castaneda-Ouellet S, Laplante I, Robinson MJF, Samaha AN. Relapse after intermittent access to cocaine: Discriminative cues more effectively trigger drug seeking than do conditioned cues. Psychopharmacology (Berl) 2024:10.1007/s00213-024-06614-9. [PMID: 38767684 DOI: 10.1007/s00213-024-06614-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Accepted: 05/12/2024] [Indexed: 05/22/2024]
Abstract
RATIONALE When people with drug addiction encounter cues associated with drug use, this can trigger cravings and relapse. These cues can include conditioned stimuli (CSs) signaling drug delivery and discriminative stimuli (DSs) signaling drug availability. Compared to CS effects, DS effects are less explored in preclinical studies on cue-induced relapse. OBJECTIVE We compared CS and DS effects on reward seeking following abstinence from intermittent-access cocaine (or sucrose) self-administration. METHODS During 15-20 intermittent-access sessions, rats self-administered i.v. cocaine or sucrose pellets paired with a light-tone CS. Cocaine/sucrose was available for 5-min (signalled by a light; DS+) and unavailable for 25 min (signalled by different lighting conditions; DS-), and this cycled for 4 h/session. Following abstinence, we measured cocaine/sucrose seeking under extinction triggered by CS and DS presentation, and instrumental responding reinforced by these cues. RESULTS Across intermittent-access sessions, rats increased lever pressing for cocaine or sucrose during DS+ periods and decreased responding during DS- periods. On days 2 and 21 of abstinence, only presentation of the DS+ or DS+ and CS combined elicited increased cocaine/sucrose-seeking behaviour (i.e., increased active lever presses). Presenting the DS- alongside the DS+ suppressed the increased cocaine-seeking behaviour otherwise produced by the DS+ . Finally, on day 21 of abstinence, rats showed equivalent levels of lever pressing reinforced by the DS+ , CS and by the DS+ and CS combined, suggesting comparable conditioned reinforcing value. CONCLUSIONS After intermittent self-administration, cocaine-associated DSs and CSs acquire similar conditioned reinforcing properties, but DSs more effectively trigger increases in drug seeking.
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Affiliation(s)
- Ndeye Aissatou Ndiaye
- Department of Neurosciences, Faculty of Medicine, Université de Montréal, Montréal, QC, H3C 3J7, Canada
| | - Sema Abu Shamleh
- Department of Psychology, Concordia University, Montréal, QC, H3G 1M8, Canada
| | - Domiziana Casale
- Department of Psychology, Université de Montréal, Montréal, QC, H3C 3J7, Canada
| | | | - Isabel Laplante
- Department of Pharmacology and Physiology, Faculty of Medicine, Université de Montréal, C.P. 6128, Succursale Centre-Ville Montréal, Montréal, Québec, H3C 3J7, Canada
| | - Mike J F Robinson
- Department of Psychology, Concordia University, Montréal, QC, H3G 1M8, Canada
- Department of Pharmacology and Physiology, Faculty of Medicine, Université de Montréal, C.P. 6128, Succursale Centre-Ville Montréal, Montréal, Québec, H3C 3J7, Canada
| | - Anne-Noël Samaha
- Department of Pharmacology and Physiology, Faculty of Medicine, Université de Montréal, C.P. 6128, Succursale Centre-Ville Montréal, Montréal, Québec, H3C 3J7, Canada.
- Neural Signaling and Circuitry Research Group (SNC), Faculty of Medicine, Université de Montréal, Montréal, QC, H3C 3J7, Canada.
- Center for Interdisciplinary Research On the Brain and Learning (CIRCA), Université de Montréal, Montréal, QC, H3C 3J7, Canada.
- Center for Studies in Behavioral Neurobiology, Department of Psychology, Concordia University, Montréal, QC, H3G 1M8, Canada.
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Robinson MJF, Bonmariage QSA, Samaha AN. Unpredictable, intermittent access to sucrose or water promotes increased reward pursuit in rats. Behav Brain Res 2023; 453:114612. [PMID: 37544370 DOI: 10.1016/j.bbr.2023.114612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 07/18/2023] [Accepted: 08/02/2023] [Indexed: 08/08/2023]
Abstract
Reward uncertainty can sensitize reward pathways, promoting increased reward-seeking and -taking behaviours. This is relevant to human conditions such as pathological gambling, eating disorders and drug addiction. In the context of addiction, preclinical self-administration procedures have been developed to model the intermittency of human drug use. These intermittent-access (IntA) procedures involve intermittent but predictable access to drug during self-administration sessions. However, human drug use typically involves intermittent and unpredictable drug access. We introduce a new procedure modeling unpredictable, intermittent access (UIntA) to a reinforcer, and we compare it to procedures that provide predictable reinforcer availability; continuous (ContA) or intermittent (IntA) access. Female rats self-administered water or liquid sucrose in daily hour-long sessions. IntA and ContA rats had access to a fixed volume of water or sucrose (0.1 ml), under a fixed ratio 3 schedule of reinforcement. IntA rats had predictable 5-min reinforcer ON and 25-min reinforcer OFF periods. ContA rats had 60 min of reinforcer access during each session. For UIntA rats, variation in the length of ON and OFF periods (1, 5 or 9 min/period), response requirement (variable ratio 3 schedule of reinforcement), reinforcer probability (50%) and quantity (0, 0.1 or 0.2 ml) introduced reward uncertainty. Following 14 daily self-administration sessions, UIntA rats showed the highest levels of responding for water or sucrose under progressive ratio conditions, responding under extinction conditions, and cue-induced reinstatement of sucrose seeking. Thus, unpredictable, intermittent reward access promotes increased reward pursuit. This has implications for modeling addiction and other disorders of increased reward seeking.
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Affiliation(s)
- Mike J F Robinson
- Department of Pharmacology and Physiology, Faculty of Medicine, Université de Montréal, Montréal, QC H3T 1J4, Canada
| | - Qi Shan A Bonmariage
- Department of Neurosciences, Faculty of Medicine, Université de Montréal, Montréal, QC H3T 1J4, Canada
| | - Anne-Noël Samaha
- Department of Pharmacology and Physiology, Faculty of Medicine, Université de Montréal, Montréal, QC H3T 1J4, Canada; Neural Signaling and Circuitry Research Group (SNC), Faculty of Medicine, Université de Montréal, Montréal, QC H3T 1J4, Canada; Center for Interdisciplinary Research on the Brain and Learning (CIRCA), Université de Montréal, Montréal, QC H3T 1J4, Canada; Neuroscience and Mental Health Strategy of the Université de Montréal (SENSUM), Université de Montréal, Montréal, QC H3T 1J4, Canada.
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Saraswat AA, Longyear LG, Kawa AB, Ferrario CR. Cocaine-induced plasticity, motivation, and cue responsivity do not differ in obesity-prone vs obesity-resistant rats; implications for food addiction. Psychopharmacology (Berl) 2023; 240:853-870. [PMID: 36806961 PMCID: PMC10006066 DOI: 10.1007/s00213-023-06327-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Accepted: 01/25/2023] [Indexed: 02/20/2023]
Abstract
RATIONALE Compared to obesity-resistant rats, obesity-prone rats consume more food, work harder to obtain food, show greater motivational responses to food-cues, and show greater striatal plasticity in response to eating sugary/fatty foods. Therefore, it is possible that obesity-prone rats may also be more sensitive to the motivational properties of cocaine and cocaine-paired cues, and to plasticity induced by cocaine. OBJECTIVE To examine baseline differences in motivation for cocaine and effects of intermittent access (IntA) cocaine self-administration on cocaine motivation, neurobehavioral responsivity to cocaine-paired cues, and locomotor sensitization in male obesity-prone vs obesity-resistant rats. METHODS Intravenous cocaine self-administration was used to examine drug-taking and drug-seeking in males. Motivation for cocaine was measured using a within session threshold procedure. Cue-induced c-Fos expression in mesocorticolimbic regions was measured. RESULTS Drug-taking and drug-seeking, cue-induced c-Fos, locomotor sensitization, and preferred level of cocaine consumption (Q0) were similar between obesity-prone and obesity-resistant groups. Maximal responding during demand testing (Rmax) was lower in obesity-prone rats. IntA experience enhanced motivation for cocaine (Pmax) in obesity-prone rats. CONCLUSIONS The results do not support robust inherent differences in motivation for cocaine, cue-induced cocaine seeking, or neurobehavioral plasticity induced by IntA in obesity-prone vs obesity-resistant rats. This contrasts with previously established differences seen for food and food cues in these populations and shows that inherent enhancements in motivation for food and food-paired cues do not necessarily transfer to drugs and drug-paired cues.
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Affiliation(s)
- Anish A Saraswat
- Department of Pharmacology, University of Michigan, Ann Arbor, MI, 48109, USA
- Psychology Department (Biopsychology), University of Michigan, Ann Arbor, MI, 48109, USA
| | - Lauren G Longyear
- Psychology Department (Biopsychology), University of Michigan, Ann Arbor, MI, 48109, USA
| | - Alex B Kawa
- Psychology Department (Biopsychology), University of Michigan, Ann Arbor, MI, 48109, USA
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Carrie R Ferrario
- Department of Pharmacology, University of Michigan, Ann Arbor, MI, 48109, USA.
- Psychology Department (Biopsychology), University of Michigan, Ann Arbor, MI, 48109, USA.
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Beasley MM, Gunawan T, Tunstall BJ, Kearns DN. Intermittent access training produces greater motivation for a non-drug reinforcer than long access training. Learn Behav 2022; 50:509-523. [PMID: 35132517 PMCID: PMC10237344 DOI: 10.3758/s13420-022-00512-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/16/2022] [Indexed: 01/01/2023]
Abstract
It has recently been proposed that the intermittent access (IntA) drug self-administration procedure better produces behavioral changes relevant to addiction than the long access (LgA) procedure. In this version of the IntA procedure, the drug is made available for a 5-min period during each half hour of a 6-h session. In contrast, on the LgA procedure, the drug is available continuously for 6 h. Previous studies have found that IntA drug self-administration produces greater drug motivation, measured by increased progressive ratio breakpoints, than LgA self-administration. It has been hypothesized that this effect is due to the rapid, "spiking" brain levels of the drug, and consequent neuroadaptations, experienced by rats during IntA sessions. However, no study has compared the effects of IntA versus LgA training on reinforcer motivation when using a non-drug reinforcer. The present study compared motivation for a saccharin reinforcer after IntA or LgA training. In Experiment 1, separate groups of rats lever-pressed for saccharin on the IntA or LgA procedures. In Experiment 2, a within-subjects design was used where rats pressed one lever on the IntA procedure and another lever on the LgA procedure for saccharin. In both experiments, IntA training produced greater breakpoints than LgA training. As no drug was used here, spiking drug levels could not have been responsible for the increased saccharin motivation observed after IntA training. Instead, it is proposed that differences in stimulus-reinforcer associations learned during IntA versus LgA training may be responsible for the effect. Future research is needed to determine the extent to which such learning factors may contribute to the increased motivation observed after IntA training with drug reinforcers.
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Affiliation(s)
- Madeline M Beasley
- Psychology Department, American University, 4400 Massachusetts Ave NW, Washington, DC, 20016, USA.
| | - Tommy Gunawan
- Human Psychopharmacology Laboratory, NIH/NIAAA, Bethesda, MD, USA
| | - Brendan J Tunstall
- Department of Pharmacology, Addiction Science, and Toxicology, University of Tennessee Health Sciences Center, Memphis, TN, USA
| | - David N Kearns
- Psychology Department, American University, 4400 Massachusetts Ave NW, Washington, DC, 20016, USA
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D-amphetamine maintenance therapy reduces cocaine use in female rats. Psychopharmacology (Berl) 2022; 239:3755-3770. [PMID: 36357743 DOI: 10.1007/s00213-022-06271-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 10/19/2022] [Indexed: 11/12/2022]
Abstract
RATIONALE D-amphetamine maintenance therapy is a promising strategy to reduce drug use in cocaine use disorder (addiction). In both male rats and human cocaine users, d-amphetamine treatment reduces cocaine-taking and -seeking. However, this has not been examined systematically in female animals, even though cocaine addiction afflicts both sexes, and the sexes can differ in their response to cocaine. OBJECTIVES We determined how d-amphetamine maintenance therapy during cocaine self-administration influences cocaine use in female rats. METHODS In experiment 1, two groups of female rats received 14 intermittent access (IntA) cocaine self-administration sessions. One group received concomitant d-amphetamine maintenance treatment (COC + A rats; 5 mg/kg/day, via minipump), the other group did not (COC rats). After discontinuing d-amphetamine treatment, we measured responding for cocaine under a progressive ratio schedule, responding under extinction, and cocaine-primed reinstatement of drug-seeking. In experiment 2, we assessed the effects of d-amphetamine maintenance on these measures in already IntA cocaine-experienced rats. Thus, rats first received 14 IntA cocaine self-administration sessions without d-amphetamine. They then received 14 more IntA sessions, now either with (COC/COC + A rats) or without (COC/COC rats) concomitant d-amphetamine treatment. RESULTS In both experiments, d-amphetamine treatment did not significantly influence ongoing cocaine self-administration behaviour. After d-amphetamine treatment cessation, cocaine-primed reinstatement of cocaine-seeking was also unchanged. However, after d-amphetamine treatment cessation, rats responded less for cocaine both under progressive ratio and extinction conditions. CONCLUSIONS D-amphetamine treatment can both prevent and reverse increases in the motivation to take and seek cocaine in female animals.
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Jiang C, Xu Y, Zhong J, Wu J, He J, Xu W, Zhu Y. Chloral Hydrate Alters Brain Activation Induced by Methamphetamine-Associated Cue and Prevents Relapse. Front Mol Neurosci 2022; 15:934167. [PMID: 35898698 PMCID: PMC9309691 DOI: 10.3389/fnmol.2022.934167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Accepted: 06/10/2022] [Indexed: 12/03/2022] Open
Abstract
Methamphetamine is a highly addictive drug and its abuse leads to serious health and social problems. Until now, no effective medications are yet available for the treatment of methamphetamine addiction. Our study reveals that chloral hydrate, a clinical sedative drug, suppresses the seeking desire for methamphetamine. After 5 days of continuous administration (subanesthetic dose 50 mg/kg and 100 mg/kg), methamphetamine-seeking behavior of rats was inhibited in the condition place preference and intravenous self-administration tests. Furthermore, chloral hydrate treatment robustly suppressed cue-induced methamphetamine relapse. The whole brain c-fos immunostaining revealed that chloral hydrate treatment suppressed neuronal activity in the rhomboid thalamic nucleus (Rh), dorsal endopiriform nucleus (dEn), and claustrum (Cl) while enhanced zona incerta (ZI) activity during cue-induced methamphetamine relapse. Therefore, chloral hydrate could remodel neural network activity and serve as a potential medicine to treat methamphetamine addiction.
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Affiliation(s)
- Chenyu Jiang
- Shenzhen Key Laboratory of Drug Addiction, Shenzhen Neher Neural Plasticity Laboratory, The Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Chinese Academy of Sciences, Shenzhen, China
- College of Life Science, University of Chinese Academy of Sciences, Beijing, China
| | - Yunlong Xu
- Shenzhen Key Laboratory of Drug Addiction, Shenzhen Neher Neural Plasticity Laboratory, The Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Chinese Academy of Sciences, Shenzhen, China
- College of Life Science, University of Chinese Academy of Sciences, Beijing, China
| | - Jiafeng Zhong
- Shenzhen Key Laboratory of Drug Addiction, Shenzhen Neher Neural Plasticity Laboratory, The Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Chinese Academy of Sciences, Shenzhen, China
- College of Life Science, University of Chinese Academy of Sciences, Beijing, China
| | - Junyan Wu
- Shenzhen Key Laboratory of Drug Addiction, Shenzhen Neher Neural Plasticity Laboratory, The Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Chinese Academy of Sciences, Shenzhen, China
- The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
- Medical College of Acupuncture-Moxibustion and Rehabilitation, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Jian He
- Shenzhen Key Laboratory of Drug Addiction, Shenzhen Neher Neural Plasticity Laboratory, The Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Chinese Academy of Sciences, Shenzhen, China
- Department of Anesthesiology, The First People’s Hospital of Foshan, Foshan, China
| | - Wei Xu
- Shenzhen Key Laboratory of Drug Addiction, Shenzhen Neher Neural Plasticity Laboratory, The Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Chinese Academy of Sciences, Shenzhen, China
- College of Life Science, University of Chinese Academy of Sciences, Beijing, China
- *Correspondence: Wei Xu,
| | - Yingjie Zhu
- Shenzhen Key Laboratory of Drug Addiction, Shenzhen Neher Neural Plasticity Laboratory, The Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Chinese Academy of Sciences, Shenzhen, China
- College of Life Science, University of Chinese Academy of Sciences, Beijing, China
- Faculty of Life and Health Sciences, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
- CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
- Yingjie Zhu,
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Conditioned Inhibition of Amphetamine Sensitization. Neurobiol Learn Mem 2022; 192:107636. [PMID: 35597434 DOI: 10.1016/j.nlm.2022.107636] [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: 01/29/2022] [Revised: 05/06/2022] [Accepted: 05/13/2022] [Indexed: 11/20/2022]
Abstract
Repeated intermittent exposure to psychostimulants, such as amphetamine, leads to a progressive enhancement of the drug's ability to increase both behavioral and brain neurochemical responses. The expression of these enhancements, known as sensitization, can be regulated by Pavlovian conditioned stimuli. Cues that are associated with drug experience can facilitate sensitization so that it only occurs in the presence of these stimuli (context-specific sensitization). In contrast, cues that are explicitly related to the absence of drugs (conditioned inhibitors) can prevent the expression of sensitization. We hypothesized that disrupting conditioned inhibition would enable amphetamine sensitization in new contexts. Using male Sprague Dawley rats and a two-context amphetamine conditioning procedure, we found that extinguishing amphetamine experience in one environment led to the loss of conditioned inhibition in a separate context. Thus, amphetamine-induced sensitized locomotion, as well as both enhanced dopamine and glutamate neurotransmission in the nucleus accumbens, were observed in a context where the drug was never experienced before. A similar loss of contextual control of sensitization was seen after using baclofen/muscimol microinjections to transiently inhibit the medial prefrontal cortex, basolateral amygdala, or ventral subiculum of the hippocampus. In other words, compared to control infusions, these intracranial injections of GABA-receptor agonists were able to block conditioned inhibitors from preventing the expression of sensitized locomotion. Together, these findings reveal the importance of conditioned inhibitors for regulating addiction-like behavior. The results suggest that dopaminergic and glutamatergic brain circuitry controls the context-specific expression of amphetamine sensitization.
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Dopamine 'ups and downs' in addiction revisited. Trends Neurosci 2021; 44:516-526. [PMID: 33892963 DOI: 10.1016/j.tins.2021.03.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 01/14/2021] [Accepted: 03/16/2021] [Indexed: 12/11/2022]
Abstract
Repeated drug use can change dopamine (DA) function in ways that promote the development and persistence of addiction, but in what direction? By one view, drug use blunts DA neurotransmission, producing a hypodopaminergic state that fosters further drug use to overcome a DA deficiency. Another view is that drug use enhances DA neurotransmission, producing a sensitized, hyperdopaminergic reaction to drugs and drug cues. According to this second view, continued drug use is motivated by sensitization of drug 'wanting'. Here we discuss recent evidence supporting the latter view, both from preclinical studies using intermittent cocaine self-administration procedures that mimic human patterns of use and from related human neuroimaging studies. These studies have implications for the modeling of addiction in the laboratory and for treatment.
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Bidirectional role of acupuncture in the treatment of drug addiction. Neurosci Biobehav Rev 2021; 126:382-397. [PMID: 33839169 DOI: 10.1016/j.neubiorev.2021.04.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Revised: 04/02/2021] [Accepted: 04/05/2021] [Indexed: 02/06/2023]
Abstract
Drug addiction is a chronically relapsing disorder, affecting people from all walks of life. Studies of acupuncture effects on drug addiction are intriguing in light of the fact that acupuncture can be used as a convenient therapeutic intervention for treating drug addiction by direct activation of brain pathway. The current review aims to discuss the neurobiological mechanisms underlying acupuncture's effectiveness in the treatment of drug addiction, on the basis of two different theories (the incentive sensitization theory and the opponent process theory) that have seemingly opposite view on the role of the mesolimbic reward pathways in mediating compulsive drug-seeking behavior. This review provides evidence that acupuncture may reduce relapse to drug-seeking behavior by regulating neurotransmitters involved in drug craving modulation via somatosensory afferent mechanisms. Also, acupuncture normalizes hyper-reactivity or hypoactivity of the mesolimbic dopamine system in these opposed processes in drug addiction, suggesting bidirectional role of acupuncture in regulation of drug addiction. This proposes that acupuncture may reduce drug craving by correcting both dysfunctions of the mesolimbic dopamine pathway.
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D-amphetamine maintenance treatment goes a long way: lasting therapeutic effects on cocaine behavioral effects and cocaine potency at the dopamine transporter. Neuropsychopharmacology 2021; 46:275-276. [PMID: 32859997 PMCID: PMC7852542 DOI: 10.1038/s41386-020-00825-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Accepted: 08/14/2020] [Indexed: 11/08/2022]
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