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Hanna C, Yao R, Sajjad M, Gold M, Blum K, Thanos PK. Exercise Modifies the Brain Metabolic Response to Chronic Cocaine Exposure Inhibiting the Stria Terminalis. Brain Sci 2023; 13:1705. [PMID: 38137153 PMCID: PMC10742065 DOI: 10.3390/brainsci13121705] [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: 11/08/2023] [Revised: 11/28/2023] [Accepted: 12/02/2023] [Indexed: 12/24/2023] Open
Abstract
It is well known that exercise promotes health and wellness, both mentally and physiologically. It has been shown to play a protective role in many diseases, including cardiovascular, neurological, and psychiatric diseases. The present study examined the effects of aerobic exercise on brain glucose metabolic activity in response to chronic cocaine exposure in female Lewis rats. Rats were divided into exercise and sedentary groups. Exercised rats underwent treadmill running for six weeks and were compared to the sedentary rats. Using positron emission tomography (PET) and [18F]-Fluorodeoxyglucose (FDG), metabolic changes in distinct brain regions were observed when comparing cocaine-exposed exercised rats to cocaine-exposed sedentary rats. This included activation of the secondary visual cortex and inhibition in the cerebellum, stria terminalis, thalamus, caudate putamen, and primary somatosensory cortex. The functional network of this brain circuit is involved in sensory processing, fear and stress responses, reward/addiction, and movement. These results show that chronic exercise can alter the brain metabolic response to cocaine treatment in regions associated with emotion, behavior, and the brain reward cascade. This supports previous findings of the potential for aerobic exercise to alter the brain's response to drugs of abuse, providing targets for future investigation. These results can provide insights into the fields of exercise neuroscience, psychiatry, and addiction research.
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Affiliation(s)
- Colin Hanna
- Behavioral Neuropharmacology and Neuroimaging Laboratory on Addictions, Clinical Research Institute on Addictions, Department of Pharmacology and Toxicology, Jacob School of Medicine and Biosciences, State University of New York at Buffalo, Buffalo, NY 14203, USA
| | - Rutao Yao
- Department of Nuclear Medicine, State University of New York at Buffalo, Buffalo, NY 14203, USA
| | - Munawwar Sajjad
- Department of Nuclear Medicine, State University of New York at Buffalo, Buffalo, NY 14203, USA
| | - Mark Gold
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Kenneth Blum
- Division of Addiction Research and Education, Center for Sports, Exercise and Global Mental Health, Western University Health Sciences, Pomona, CA 91766, USA
| | - Panayotis K. Thanos
- Behavioral Neuropharmacology and Neuroimaging Laboratory on Addictions, Clinical Research Institute on Addictions, Department of Pharmacology and Toxicology, Jacob School of Medicine and Biosciences, State University of New York at Buffalo, Buffalo, NY 14203, USA
- Department of Psychology, State University of New York at Buffalo, Buffalo, NY 14203, USA
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Mamidi RS, Ayubcha C, Rigney G, Kirschner J, Gerke O, Werner TJ, Tebas P, Alavi A, Revheim ME. A prospective 18 F-fluorodeoxyglucose positron emission tomography/computed tomography study of the neurometabolic effects in cocaine use and HIV infection. AIDS 2023; 37:905-912. [PMID: 36727840 PMCID: PMC10090338 DOI: 10.1097/qad.0000000000003485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 12/25/2022] [Accepted: 01/11/2023] [Indexed: 02/03/2023]
Abstract
OBJECTIVES HIV affects 36 million people globally with prevalence decreasing due to antiretroviral therapy (ART) and social awareness; transmission occurs during substance use. Cocaine usage independently affects brain activity and may result in reduced ART adherence. This study evaluates brain glucose metabolism measured by 18 F-fluorodeoxyglucose positron emission tomography/computed tomography ( 18 F-FDG PET/CT) in cocaine users with HIV infection. DESIGN Sixty-three participants were categorized into groups: 36 HIV infected (HIV+) and 27 non-HIV infected (HIV-) individuals. Each group was further split into cocaine users (CO+) and non-cocaine users (CO-). Of the HIV+, half were cocaine users and half were not. Of the HIV-, 14 were cocaine users and 13 were not. 18 F-FDG-PET and low dose CT scans were performed on all participants. METHODS Brain glucose metabolism was evaluated by 18 F-FDG uptake in the whole brain, cortex, basal ganglia, and cerebellum 120 min after injection. ROVER software was used for image analysis and regions of interest masks were applied via an adaptive threshold system. ANOVA tests and t -tests were performed to assess the respective differences between the four groups. RESULTS Generally, the HIV+/CO+ group (group A) displayed the lowest levels of uptake whereas the HIV-/CO- group (group D) showed the highest; the HIV+/CO- and HIV-/CO+ groups (groups B and C) showed intermediate levels of activity across the whole brain, cortex, basal ganglia, and cerebellum. CONCLUSION HIV infection and cocaine usage were independently associated with a decrease in brain glucose uptake as measured by 18 F-FDG PET/CT. When combined, positive HIV status and cocaine patients showed the most decreased 18 F-FDG uptake.
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Affiliation(s)
- Ramya S. Mamidi
- Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania
| | | | | | - Jason Kirschner
- Division of Infectious Diseases/Clinical Trials Unit, Department of Medicine, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Oke Gerke
- Department of Nuclear Medicine, Odense University Hospital, Odense, Denmark
| | - Thomas J. Werner
- Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania
| | - Pablo Tebas
- Division of Infectious Diseases/Clinical Trials Unit, Department of Medicine, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Abass Alavi
- Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania
| | - Mona-Elisabeth Revheim
- Division of Radiology and Nuclear Medicine, Oslo University Hospital
- Faculty of Medicine, University of Oslo, Oslo, Norway
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Gold MS, Baron D, Bowirrat A, Blum K. Neurological correlates of brain reward circuitry linked to opioid use disorder (OUD): Do homo sapiens acquire or have a reward deficiency syndrome? J Neurol Sci 2020; 418:117137. [PMID: 32957037 PMCID: PMC7490287 DOI: 10.1016/j.jns.2020.117137] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 08/19/2020] [Accepted: 09/08/2020] [Indexed: 12/14/2022]
Abstract
The extant literature confirms that an array of polymorphic genes related to- neurotransmitters and second messengers govern the net release of dopamine in the Nucleus Accumbens (NAc) in the mesolimbic region of the brain. They are linked predominantly to motivation, anti-stress, incentive salience (wanting), and wellbeing. Notably, in 2000 the Nobel Prize was awarded to Carlsson, Greengard, and Kandel for their work on the molecular and cellular function of dopaminergic activity at neurons. This historical psychopharmacological work involved neurotransmission of serotonin, endorphins, glutamate, and dopamine, and the seminal work of Blum, Gold, Volkow, Nestler, and others related to neurotransmitter function and related behaviors. Currently, Americans are facing their second and worst opioid epidemic, prescribed opioids, and easy access drive this epidemic of overdoses, and opioid use disorders (OUDs). Presently the clinical consensus is to treat OUD, as if it were an opioid deficiency syndrome, with long-term to life-long opioid substitution therapy. Opioid agonist administration is seen as necessary to replace missing opioids, treat OUD, and prevent overdoses, like insulin is used to treat diabetes. Treatment of OUD and addiction, in general, is similar to the endocrinopathy conceptualization in that it views opioid agonist MATs as an essential core to therapy. Is this approach logical? Other than as harm reduction, is using opioids to treat OUD therapeutic or harmful in the long term? This historical Trieste provides a molecular framework to understand the current underpinnings of endorphinergic/dopaminergic mechanisms related to opioid deficiency syndrome and generalized reward processing depletion. WC 249.
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Affiliation(s)
- Mark S Gold
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, United States.
| | - David Baron
- Graduate School of Biomedical Sciences, Western University Health Sciences, Pomona, CA, United States
| | - Abdalla Bowirrat
- Department of Neuroscience and Genetics, Interdisciplinary Center Herzliya, Israel
| | - Kenneth Blum
- Graduate School of Biomedical Sciences, Western University Health Sciences, Pomona, CA, United States
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Relapse Risk Factors in Heroin Addicts Treated with Naltrexone and Naltrexone-Behavioural Psychotherapy. Int J Ment Health Addict 2017. [DOI: 10.1007/s11469-017-9782-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
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Chen YI, Famous K, Xu H, Choi JK, Mandeville JB, Schmidt HD, Pierce RC, Jenkins BG. Cocaine self-administration leads to alterations in temporal responses to cocaine challenge in limbic and motor circuitry. Eur J Neurosci 2011; 34:800-15. [PMID: 21896062 PMCID: PMC3172610 DOI: 10.1111/j.1460-9568.2011.07806.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Chronic use of cocaine is associated with lasting alterations in brain metabolism, circuitry, and receptor properties. We used neuroimaging with pharmacological magnetic resonance imaging to assess alterations in response to cocaine (0.5 mg/kg) in animals trained to self-administer cocaine on a fixed-ratio 5 schedule of reinforcement, as well as saline-yoked controls, after 28 days of cocaine abstinence. We fitted the cerebral blood volume (CBV) curves for full-width half-maximum (FWHM) as well as peak CBV response. There were significant increases in the FWHM of the response curves in the cocaine self-administering (SA) animals as compared with saline-yoked controls in the medial prefrontal cortex (mPFC) and the caudate/putamen (CPu), and increases in peak CBV in the M1 motor cortex, CPu, and pedunculopontine tegmental nucleus. Functional connectivity analysis showed increased correlations in the cocaine SA rats upon acute cocaine challenge, especially in the S1, mPFC, and thalamus. As D3 receptor expression is postulated to increase following chronic cocaine administration, we also examined the response to 0.2 mg/kg of the D3-preferring agonist 7-hydroxy-N,N-di-n-propyl-2-aminotetralin (7-OHDPAT). Cocaine SA animals showed a decreased overall CBV response to this drug, except in the globus pallidus. The hypothalamus showed a negative CBV change in response to cocaine challenge, similar to that noted with the D3 agonist, and showed a smaller response in the cocaine SA animals than in the controls. Given the good coupling of cerebral hemodynamics with dopamine dynamics previously observed with pharmacological magnetic resonance imaging, these data suggest that increased persistence of dopamine in the prefrontal cortex may be responsible for some of the behavioral alterations observed subsequent to chronic cocaine use.
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Affiliation(s)
- Y Iris Chen
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA.
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Duka T, Crombag HS, Stephens DN. Experimental medicine in drug addiction: towards behavioral, cognitive and neurobiological biomarkers. J Psychopharmacol 2011; 25:1235-55. [PMID: 21169391 DOI: 10.1177/0269881110388324] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Several theoretical frameworks have been developed to understand putative processes and mechanisms involved in addiction. Whilst these 'theories of addiction' disagree about importance and/or nature of a number of key psychological processes (e.g. the necessity of craving and/or the involvement of drug-value representations), a number of commonalities exist. For instance, it is widely accepted that Pavlovian associations between cues and environmental contexts and the drug effects acquired over the course of addiction play a critical role, especially in relapse vulnerability in detoxified addicts. Additionally, all theories of addiction (explicitly or implicitly) propose that chronic drug exposure produces persistent neuroplastic changes in neurobiological circuitries underlying critical emotional, cognitive and motivational processes, although disagreement exists as to the precise nature of these neurobiological changes and/or their psychological consequences. The present review, rather than limiting itself to any particular theoretical stance, considers various candidate psychological, neurobiological and/or behavioral processes in addiction and outlines conceptual and procedural approaches for the experimental medicine laboratory. The review discusses (1) extinction, renewal and (re)consolidation of learned associations between cues and drugs, (2) the drug reward value, (3) motivational states contributing to drug seeking and (4) reflective (top-down) and sensory (bottom-up) driven decision-making. In evaluating these psychological and/or behavioral processes and their relationship to addiction we make reference to putative underlying brain structures identified by basic animal studies and/or imaging studies with humans.
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Affiliation(s)
- Theodora Duka
- Behavioral and Clinical Neuroscience Research Group, School of Psychology, University of Sussex, Brighton, UK.
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Koob GF, Volkow ND. Neurocircuitry of addiction. Neuropsychopharmacology 2010; 35:217-38. [PMID: 19710631 PMCID: PMC2805560 DOI: 10.1038/npp.2009.110] [Citation(s) in RCA: 3419] [Impact Index Per Article: 244.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2009] [Revised: 07/13/2009] [Accepted: 07/14/2009] [Indexed: 12/29/2022]
Abstract
Drug addiction is a chronically relapsing disorder that has been characterized by (1) compulsion to seek and take the drug, (2) loss of control in limiting intake, and (3) emergence of a negative emotional state (eg, dysphoria, anxiety, irritability) reflecting a motivational withdrawal syndrome when access to the drug is prevented. Drug addiction has been conceptualized as a disorder that involves elements of both impulsivity and compulsivity that yield a composite addiction cycle composed of three stages: 'binge/intoxication', 'withdrawal/negative affect', and 'preoccupation/anticipation' (craving). Animal and human imaging studies have revealed discrete circuits that mediate the three stages of the addiction cycle with key elements of the ventral tegmental area and ventral striatum as a focal point for the binge/intoxication stage, a key role for the extended amygdala in the withdrawal/negative affect stage, and a key role in the preoccupation/anticipation stage for a widely distributed network involving the orbitofrontal cortex-dorsal striatum, prefrontal cortex, basolateral amygdala, hippocampus, and insula involved in craving and the cingulate gyrus, dorsolateral prefrontal, and inferior frontal cortices in disrupted inhibitory control. The transition to addiction involves neuroplasticity in all of these structures that may begin with changes in the mesolimbic dopamine system and a cascade of neuroadaptations from the ventral striatum to dorsal striatum and orbitofrontal cortex and eventually dysregulation of the prefrontal cortex, cingulate gyrus, and extended amygdala. The delineation of the neurocircuitry of the evolving stages of the addiction syndrome forms a heuristic basis for the search for the molecular, genetic, and neuropharmacological neuroadaptations that are key to vulnerability for developing and maintaining addiction.
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Affiliation(s)
- George F Koob
- Committee on the Neurobiology of Addictive Disorders, The Scripps Research Institute, La Jolla, CA 92037, USA.
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Ding YS, Singhal T, Planeta-Wilson B, Gallezot JD, Nabulsi N, Labaree D, Ropchan J, Henry S, Williams W, Carson RE, Neumeister A, Malison RT. PET imaging of the effects of age and cocaine on the norepinephrine transporter in the human brain using (S,S)-[(11)C]O-methylreboxetine and HRRT. Synapse 2010; 64:30-8. [PMID: 19728366 PMCID: PMC3727644 DOI: 10.1002/syn.20696] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
OBJECTIVES The role of the norepinephrine transporter (NET) in cocaine dependence has never been demonstrated via in vivo imaging due to the lack of suitable NET radioligands. Here we report our preliminary studies evaluting the NET in individuals with cocaine dependence (COC) in comparison to healthy controls (HC) using (S,S)-[(11)C]methylreboxetine ([(11)C]MRB), the most promising C-11 labeled positron-emission tomography (PET) radioligand for NET developed to date. METHODS Twenty two human volunteers (10 COC and 12 HC) underwent dynamic (11)C-MRB-PET acquisition using a High Resolution Research Tomograph (HRRT). Binding potential (BP(ND)) parametric images were computed using the simplified reference tissue model (SRTM2) with occipital cortex as reference region. BP(ND) values were compared between the two groups. RESULTS Locus coeruleus (LC), hypothalamus, and pulvinar showed a significant inverse correlation with age among HC (age range = 25-54 years; P = 0.04, 0.009, 0.03 respectively). The BP(ND) was significantly increased in thalamus (27%; P < 0.02) and dorsomedial thalamic nuclei (30%; P < 0.03) in COC as compared to HC. Upon age normalization, the upregulation of NET in COC also reached significance in LC (63%, P < 0.01) and pulvinar (55%, P < 0.02) regions. CONCLUSION Our results suggest that (a) brain NET concentration declines with age in HC, and (b) there is a significant upregulation of NET in thalamus and dorsomedial thalamic nucleus in COC as compared to HC. Our results also suggest that the use of [(11)C]MRB and HRRT provides an effective strategy for studying alterations of the NET system in humans.
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Affiliation(s)
- Yu-Shin Ding
- Yale PET Center, Department of Diagnostic Radiology, Yale University School of Medicine, New Haven, Connecticut 06520-8048, USA.
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Elman I, Borsook D, Lukas SE. Food intake and reward mechanisms in patients with schizophrenia: implications for metabolic disturbances and treatment with second-generation antipsychotic agents. Neuropsychopharmacology 2006; 31:2091-120. [PMID: 16541087 DOI: 10.1038/sj.npp.1301051] [Citation(s) in RCA: 107] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Obesity is highly prevalent among patients with schizophrenia and is associated with detrimental health consequences. Although excessive consumption of fast food and pharmacotherapy with such second-generation antipsychotic agents (SGAs) as clozapine and olanzapine has been implicated in the schizophrenia/obesity comorbidity, the pathophysiology of this link remains unclear. Here, we propose a mechanism based on brain reward function, a relevant etiologic factor in both schizophrenia and overeating. A comprehensive literature search on neurobiology of schizophrenia and of eating behavior was performed. The collected articles were critically reviewed and relevant data were extracted and summarized within four key areas: (1) energy homeostasis, (2) food reward and hedonics, (3) reward function in schizophrenia, and (4) metabolic effects of the SGAs. A mesolimbic hyperdopaminergic state may render motivational/incentive reward system insensitive to low salience/palatability food. This, together with poor cognitive control from hypofunctional prefrontal cortex and enhanced hedonic impact of food, owing to exaggerated opioidergic drive (clinically manifested as pain insensitivity), may underlie unhealthy eating habits in patients with schizophrenia. Treatment with SGAs purportedly improves dopamine-mediated reward aspects, but at the cost of increased appetite and worsened or at least not improved opiodergic capacity. These effects can further deteriorate eating patterns. Pathophysiological and therapeutic implications of these insights need further validation via prospective clinical trials and neuroimaging studies.
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Affiliation(s)
- Igor Elman
- Behavioral Psychopharmacology Research Laboratory, Department of Psychiatry, McLean Hospital and Harvard Medical School, Belmont, MA 02478, USA.
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Volkow ND, Wang GJ, Franceschi D, Fowler JS, Thanos PPK, Maynard L, Gatley SJ, Wong C, Veech RL, Kunos G, Kai Li T. Low doses of alcohol substantially decrease glucose metabolism in the human brain. Neuroimage 2006; 29:295-301. [PMID: 16085426 DOI: 10.1016/j.neuroimage.2005.07.004] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2005] [Revised: 06/30/2005] [Accepted: 07/04/2005] [Indexed: 11/20/2022] Open
Abstract
Moderate doses of alcohol decrease glucose metabolism in the human brain, which has been interpreted to reflect alcohol-induced decreases in brain activity. Here, we measure the effects of two relatively low doses of alcohol (0.25 g/kg and 0.5 g/kg, or 5 to 10 mM in total body H2O) on glucose metabolism in the human brain. Twenty healthy control subjects were tested using positron emission tomography (PET) and FDG after placebo and after acute oral administration of either 0.25 g/kg, or 0.5 g/kg of alcohol, administered over 40 min. Both doses of alcohol significantly decreased whole-brain glucose metabolism (10% and 23% respectively). The responses differed between doses; whereas the 0.25 g/kg dose predominantly reduced metabolism in cortical regions, the 0.5 g/kg dose reduced metabolism in cortical as well as subcortical regions (i.e. cerebellum, mesencephalon, basal ganglia and thalamus). These doses of alcohol did not significantly change the scores in cognitive performance, which contrasts with our previous results showing that a 13% reduction in brain metabolism by lorazepam was associated with significant impairment in performance on the same battery of cognitive tests. This seemingly paradoxical finding raises the possibility that the large brain metabolic decrements during alcohol intoxication could reflect a shift in the substrate for energy utilization, particularly in light of new evidence that blood-borne acetate, which is markedly increased during intoxication, is a substrate for energy production by the brain.
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Affiliation(s)
- Nora D Volkow
- National Institute on Drug Abuse, 6001 Executive Blvd., Room 5274, Bethesda, MD 20892, USA.
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Abstract
This review of negative reinforcement models of drug dependence is part of a series that takes the position that a complete understanding of current concepts of dependence will facilitate the development of reliable and valid measures of the emergence of tobacco dependence. Other reviews within the series consider models that emphasize positive reinforcement and social learning/cognitive models. This review summarizes negative reinforcement in general and then presents four current negative reinforcement models that emphasize withdrawal, classical conditioning, self-medication and opponent-processes. For each model, the paper outlines central aspects of dependence, conceptualization of dependence development and influences that the model might have on current and future measures of dependence. Understanding how drug dependence develops will be an important part of future successful tobacco dependence measurement, prevention and treatment strategies.
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Affiliation(s)
- Thomas Eissenberg
- Department of Psychology and Institute for Drug and Alcohol Studies, Virginia Commonwealth University, VA, USA.
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Elliott R, Newman JL, Longe OA, William Deakin JF. Instrumental responding for rewards is associated with enhanced neuronal response in subcortical reward systems. Neuroimage 2004; 21:984-90. [PMID: 15006665 DOI: 10.1016/j.neuroimage.2003.10.010] [Citation(s) in RCA: 103] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2003] [Revised: 10/07/2003] [Accepted: 10/07/2003] [Indexed: 11/20/2022] Open
Abstract
The response of human reward systems to different reinforcers, including food, drugs and money, has been investigated in a number of recent functional neuroimaging studies. They have varied, however, in terms of whether or not a behavioural response was required to obtain rewards. The aim of the present study was to determine whether neuronal responses to financial reward are significantly modulated by the requirement to make a behavioural response. Twelve subjects were scanned using functional magnetic resonance imaging (fMRI) while performing a simple target detection task. Certain targets acted as cues predicting financial reinforcement; some additionally required that a movement be executed, while others did not. There were also targets that required a movement but were not predictive of reward. We observed, as expected, responses within motor and reward systems associated with main effects of movement and reward, respectively. Critically, the reward responses were significantly modulated by the requirement to make an intervening behavioural response. Blood oxygenation level-dependent (BOLD) responses in the amygdala and striatum were significantly enhanced when a movement was required, while reward-related response in the orbitofrontal cortex was independent of movement. These results suggest important dissociations within human reward systems, reflecting different properties of rewards. The striatum and amygdala may mediate the function of rewards in eliciting goal-directed behaviour, while the orbitofrontal cortex mediates incentive value.
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Affiliation(s)
- Rebecca Elliott
- Neuroscience and Psychiatry Unit, University of Manchester, Manchester M13 9PT, UK.
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Volkow ND, Fowler JS, Wang GJ. The addicted human brain: insights from imaging studies. J Clin Invest 2003; 111:1444-51. [PMID: 12750391 PMCID: PMC155054 DOI: 10.1172/jci18533] [Citation(s) in RCA: 540] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Affiliation(s)
- Nora D Volkow
- Department of Medicine, Brookhaven National Laboratory, Upton, New York 11973, USA.
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