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Phan JA, Wong DF, Chang NHS, Kumakura Y, Bauer WR, Gjedde A. Transient equilibrium determination of dopamine D 2/D 3 receptor densities and affinities in brain. FRONTIERS IN NUCLEAR MEDICINE (LAUSANNE, SWITZERLAND) 2022; 2:1030387. [PMID: 36926525 PMCID: PMC10017089 DOI: 10.3389/fnume.2022.1030387] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Long-term alteration of dopaminergic neurotransmission is known to modulate the D2/D3 receptor expression in the brain. The modulation can occur as a response to pathological processes or pharmacological intervention. The receptor density can be monitored by in vivo positron emission tomography (PET) of [11C] raclopride. To obtain accurate measurements of receptor-ligand interaction, it is essential to estimate binding parameters at true (if transient) equilibrium of bound and unbound ligand quantities. We designed this study as a comparison of two quantitative approaches to transient equilibrium, the TRansient EquilibriuM BoLus Estimation (TREMBLE) method and the Transient Equilibrium Model (TEM) method, to determine binding parameters at transient equilibrium with bolus injection of the radioligand. The data demonstrates that TREMBLE unlike TEM identified the time at which equilibrium existed. TREMBLE revealed that equilibrium prevailed at one or more times after bolus injection and identified differences of receptor density among regions such as putamen and caudate nucleus. We demonstrated that TREMBLE is a quantitative approach suitable for the study of pathophysiological conditions of certain types of neurotransmission the brain.
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Affiliation(s)
- Jenny-Ann Phan
- Department of Neurology, Gødstrup Hospital, Herning, Denmark
- NIDO - Centre for Research and Education, Gødstrup Hospital, Herning, Denmark
- Department of Neurology, Aarhus University, Aarhus, Denmark
- Department of Nuclear Medicine and PET Centre, Aarhus University Hospital, Aarhus, Denmark
- Johns Hopkins Medical Institutions, Department of Radiology and Radiological Sciences, Division of Nuclear Medicine PET Center, Baltimore MD, United States
| | - Dean F. Wong
- Johns Hopkins Medical Institutions, Department of Radiology and Radiological Sciences, Division of Nuclear Medicine PET Center, Baltimore MD, United States
- Mallinckrodt Institute of Radiology, Washington University in St. Louis, St. Louis, MO, United States
| | - Natalie H. S. Chang
- Department of Nuclear Medicine and PET Centre, Aarhus University Hospital, Aarhus, Denmark
- Institute of Regional Health Research, University of Southern Denmark, Odense, Denmark
- Medical Spinal Research Unit, Spine Centre of Southern Denmark, University Hospital of Southern Denmark, Odense, Denmark
| | - Yoshitaka Kumakura
- Department of Diagnostic Radiology and Nuclear Medicine, Saitama Medical Center, Saitama Medical University, Moroyama, Japan
| | - William R. Bauer
- Translational Neuropsychiatry Unit, Department of Clinical Research, Aarhus University, Aarhus, Denmark
| | - Albert Gjedde
- Department of Nuclear Medicine and PET Centre, Aarhus University Hospital, Aarhus, Denmark
- Johns Hopkins Medical Institutions, Department of Radiology and Radiological Sciences, Division of Nuclear Medicine PET Center, Baltimore MD, United States
- Translational Neuropsychiatry Unit, Department of Clinical Research, Aarhus University, Aarhus, Denmark
- Departments of Nuclear Medicine and Clinical Research, University of Southern Denmark and Odense University Hospital, Odense, Denmark
- Department of Neuroscience, University of Copenhagen, Copenhagen, Denmark
- Department of Neurology and Neurosurgery, McGill University, Montréal, QC, Canada
- Neuroscience Center, Tabriz University of Medical Sciences, Tabriz, Iran
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2
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Gjedde A, Wong DF. Four decades of mapping and quantifying neuroreceptors at work in vivo by positron emission tomography. Front Neurosci 2022; 16:943512. [PMID: 36161158 PMCID: PMC9493011 DOI: 10.3389/fnins.2022.943512] [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: 05/13/2022] [Accepted: 07/18/2022] [Indexed: 11/16/2022] Open
Abstract
Decryption of brain images is the basis for the necessary translation of the findings from imaging to information required to meet the demands of clinical intervention. Tools of brain imaging, therefore, must satisfy the conditions dictated by the needs for interpretation in terms of diagnosis and prognosis. In addition, the applications must serve as fundamental research tools that enable the understanding of new therapeutic drugs, including compounds as diverse as antipsychotics, antidepressants, anxiolytics, and drugs serving the relief of symptoms from neurochemical disorders as unrelated as multiple sclerosis, stroke, and dementia. Here we review and explain the kinetics of methods that enable researchers to describe the brain’s work and functions. We focus on methods invented by neurokineticists and expanded upon by practitioners during decades of experimental work and on the methods that are particularly useful to predict possible future approaches to the treatment of neurochemical disorders. We provide an overall description of the basic elements of kinetics and the underlying quantification methods, as well as the mathematics of modeling the recorded brain dynamics embedded in the images we obtain in vivo. The complex presentation to follow is necessary to justify the contribution of modeling to the development of methods and to support the specifications dictated by the proposed use in clinical settings. The quantification and kinetic modeling processes are equally essential to image reconstruction and labeling of brain regions of structural or functional interest. The procedures presented here are essential tools of scientific approaches to all conventional and novel forms of brain imaging. The foundations of the kinetic and quantitative methods are keys to the satisfaction of clinicians that actively engage in treating the neurochemical disorders of mammalian brains in the fields of neurology, neurosurgery, and neuropsychiatry.
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Affiliation(s)
- Albert Gjedde
- Department of Neuroscience, University of Copenhagen, Copenhagen, Denmark
- Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
- Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- *Correspondence: Albert Gjedde,
| | - Dean F. Wong
- Department of Radiology, Psychiatry, Neurology, and Neuroscience, Mallinckrodt Institute of Radiology, Washington University, St Louis, MO, United States
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3
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Tan Z, Wei H, Song X, Mai W, Yan J, Ye W, Ling X, Hou L, Zhang S, Yan S, Xu H, Wang L. Positron Emission Tomography in the Neuroimaging of Autism Spectrum Disorder: A Review. Front Neurosci 2022; 16:806876. [PMID: 35495051 PMCID: PMC9043810 DOI: 10.3389/fnins.2022.806876] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 03/14/2022] [Indexed: 12/11/2022] Open
Abstract
Autism spectrum disorder (ASD) is a basket term for neurodevelopmental disorders characterized by marked impairments in social interactions, repetitive and stereotypical behaviors, and restricted interests and activities. Subtypes include (A) disorders with known genetic abnormalities including fragile X syndrome, Rett syndrome, and tuberous sclerosis and (B) idiopathic ASD, conditions with unknown etiologies. Positron emission tomography (PET) is a molecular imaging technology that can be utilized in vivo for dynamic and quantitative research, and is a valuable tool for exploring pathophysiological mechanisms, evaluating therapeutic efficacy, and accelerating drug development in ASD. Recently, several imaging studies on ASD have been published and physiological changes during ASD progression was disclosed by PET. This paper reviews the specific radioligands for PET imaging of critical biomarkers in ASD, and summarizes and discusses the similar and different discoveries in outcomes of previous studies. It is of great importance to identify general physiological changes in cerebral glucose metabolism, cerebral blood flow perfusion, abnormalities in neurotransmitter systems, and inflammation in the central nervous system in ASD, which may provide excellent points for further ASD research.
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Affiliation(s)
- Zhiqiang Tan
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI Center, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Huiyi Wei
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI Center, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Xiubao Song
- Department of Rehabilitation Medicine, The First Affiliated Hospital of Jinan University, Jinan University, Guangzhou, China
| | - Wangxiang Mai
- Department of Rehabilitation Medicine, The First Affiliated Hospital of Jinan University, Jinan University, Guangzhou, China
| | - Jiajian Yan
- Department of Rehabilitation Medicine, The First Affiliated Hospital of Jinan University, Jinan University, Guangzhou, China
| | - Weijian Ye
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI Center, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Xueying Ling
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI Center, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Lu Hou
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI Center, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Shaojuan Zhang
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI Center, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Sen Yan
- Guangdong-Hongkong-Macau Institute of CNS Regeneration, Ministry of Education CNS Regeneration Collaborative Joint Laboratory, Jinan University, Guangzhou, China
| | - Hao Xu
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI Center, The First Affiliated Hospital of Jinan University, Guangzhou, China
- *Correspondence: Hao Xu,
| | - Lu Wang
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI Center, The First Affiliated Hospital of Jinan University, Guangzhou, China
- Lu Wang,
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Ang YS, Cusin C, Petibon Y, Dillon DG, Breiger M, Belleau EL, Normandin M, Schroder H, Boyden S, Hayden E, Levine MT, Jahan A, Meyer AK, Kang MS, Brunner D, Gelda SE, Hooker J, El Fakhri G, Fava M, Pizzagalli DA. A multi-pronged investigation of option generation using depression, PET and modafinil. Brain 2022; 145:1854-1865. [PMID: 35150243 PMCID: PMC9166534 DOI: 10.1093/brain/awab429] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 09/17/2021] [Accepted: 10/23/2021] [Indexed: 11/14/2022] Open
Abstract
Option generation is a critical process in decision making, but previous studies have largely focused on choices between options given by a researcher. Consequently, how we self-generate options for behaviour remain poorly understood. Here, we investigated option generation in major depressive disorder and how dopamine might modulate this process, as well as the effects of modafinil (a putative cognitive enhancer) on option generation in healthy individuals. We first compared differences in self-generated options between healthy non-depressed adults [n = 44, age = 26.3 years (SD 5.9)] and patients with major depressive disorder [n = 54, age = 24.8 years (SD 7.4)]. In the second study, a subset of depressed individuals [n = 22, age = 25.6 years (SD 7.8)] underwent PET scans with 11C-raclopride to examine the relationships between dopamine D2/D3 receptor availability and individual differences in option generation. Finally, a randomized, double-blind, placebo-controlled, three-way crossover study of modafinil (100 mg and 200 mg), was conducted in an independent sample of healthy people [n = 19, age = 23.2 years (SD 4.8)] to compare option generation under different doses of this drug. The first study revealed that patients with major depressive disorder produced significantly fewer options [t(96) = 2.68, P = 0.009, Cohen's d = 0.54], albeit with greater uniqueness [t(96) = -2.54, P = 0.01, Cohen's d = 0.52], on the option generation task compared to healthy controls. In the second study, we found that 11C-raclopride binding potential in the putamen was negatively correlated with fluency (r = -0.69, P = 0.001) but positively associated with uniqueness (r = 0.59, P = 0.007). Hence, depressed individuals with higher densities of unoccupied putamen D2/D3 receptors in the putamen generated fewer but more unique options, whereas patients with lower D2/D3 receptor availability were likely to produce a larger number of similar options. Finally, healthy participants were less unique [F(2,36) = 3.32, P = 0.048, partial η2 = 0.16] and diverse [F(2,36) = 4.31, P = 0.021, partial η2 = 0.19] after taking 200 mg versus 100 mg and 0 mg of modafinil, while fluency increased linearly with dosage at a trend level [F(1,18) = 4.11, P = 0.058, partial η2 = 0.19]. Our results show, for the first time, that option generation is affected in clinical depression and that dopaminergic activity in the putamen of patients with major depressive disorder may play a key role in the self-generation of options. Modafinil was also found to influence option generation in healthy people by reducing the creativity of options produced.
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Affiliation(s)
- Yuen-Siang Ang
- Department of Psychiatry, Harvard Medical School, McLean Hospital, Belmont, MA 02478, USA,Department of Psychiatry, Harvard Medical School, Boston, MA 02215, USA,Social and Cognitive Computing Department, Institute of High Performance Computing, Agency for Science, Technology and Research (A*STAR), Singapore 138632, Singapore
| | - Cristina Cusin
- Department of Psychiatry, Harvard Medical School, Boston, MA 02215, USA,Department of Psychiatry, Harvard Medical School, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Yoann Petibon
- Department of Psychiatry, Harvard Medical School, Boston, MA 02215, USA,Department of Psychiatry, Harvard Medical School, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Daniel G Dillon
- Department of Psychiatry, Harvard Medical School, McLean Hospital, Belmont, MA 02478, USA,Department of Psychiatry, Harvard Medical School, Boston, MA 02215, USA
| | - Micah Breiger
- Department of Psychiatry, Harvard Medical School, McLean Hospital, Belmont, MA 02478, USA
| | - Emily L Belleau
- Department of Psychiatry, Harvard Medical School, McLean Hospital, Belmont, MA 02478, USA,Department of Psychiatry, Harvard Medical School, Boston, MA 02215, USA
| | - Marc Normandin
- Department of Psychiatry, Harvard Medical School, Boston, MA 02215, USA,Department of Psychiatry, Harvard Medical School, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Hans Schroder
- Department of Psychiatry, Harvard Medical School, McLean Hospital, Belmont, MA 02478, USA,Department of Psychiatry, Harvard Medical School, Boston, MA 02215, USA
| | - Sean Boyden
- Department of Psychiatry, Harvard Medical School, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Emma Hayden
- Department of Psychiatry, Harvard Medical School, Massachusetts General Hospital, Boston, MA 02114, USA
| | - M Taylor Levine
- Department of Psychiatry, Harvard Medical School, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Aava Jahan
- Department of Psychiatry, Harvard Medical School, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Ashley K Meyer
- Department of Psychiatry, Harvard Medical School, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Min Su Kang
- Department of Psychiatry, Harvard Medical School, McLean Hospital, Belmont, MA 02478, USA
| | - Devon Brunner
- Department of Psychiatry, Harvard Medical School, McLean Hospital, Belmont, MA 02478, USA
| | - Steven E Gelda
- Department of Psychiatry, Harvard Medical School, Boston, MA 02215, USA
| | - Jacob Hooker
- Department of Psychiatry, Harvard Medical School, Boston, MA 02215, USA,Department of Psychiatry, Harvard Medical School, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Georges El Fakhri
- Department of Psychiatry, Harvard Medical School, Boston, MA 02215, USA,Department of Psychiatry, Harvard Medical School, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Maurizio Fava
- Department of Psychiatry, Harvard Medical School, Boston, MA 02215, USA,Department of Psychiatry, Harvard Medical School, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Diego A Pizzagalli
- Department of Psychiatry, Harvard Medical School, McLean Hospital, Belmont, MA 02478, USA,Department of Psychiatry, Harvard Medical School, Boston, MA 02215, USA,Correspondence to: Diego A. Pizzagalli, PhD McLean Hospital, 115 Mill Street, Belmont, MA 02478, USA E-mail:
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5
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Khodaii J, Araj-Khodaei M, Vafaee MS, Wong DF, Gjedde A. Relative strengths of three linearizations of receptor availability: Saturation, Inhibition, and Occupancy plots. J Nucl Med 2021; 63:294-301. [PMID: 34088774 DOI: 10.2967/jnumed.117.204453] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 04/23/2021] [Indexed: 11/16/2022] Open
Abstract
We derived three widely used linearizations from the definition of receptor availability in molecular imaging with Positron Emission Tomography. The purpose of the present research was to determine the convergence of the results of the three methods in terms of three parameters, occupancy (s), distribution volume of the non-displaceable binding compartment (VND), and binding potential of the radioligand (BPND), in the absence of a gold standard. We tested 104 cases culled from the literature and calculated the goodness of fit of each of the Least Squares (LSM) and Deming II (DM) methods of linear regression when applied to the determination of the three main parameters, s, VND, and BPND, using the goodness of fit parameters R2, coefficient of variation (RMSE), and ‖X‖_∞ with both regression methods. We observed superior convergence among the values of s, VND, and BPND for the Inhibition and Occupancy plots. The Inhibition Plot emerged as the plot with a slightly higher degree of convergence (based on R2, RMSE and ‖X‖_∞ value). With two regression methods, Least Squares (LSM) and Deming II (DM), the estimated values of s, VND, and BPND generally converged. The Inhibition and Occupancy plots yielded the best fits to the data, according to the goodness of fit parameters, due primarily to the absent commingling of the dependent and independent variables tested with the Saturation (original Lassen) plot. In the presence of noise, the Inhibition and Occupancy plots yielded higher convergence.
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Affiliation(s)
- Javad Khodaii
- Amirkabir university of technology (Tehran Polytechnic), Iran, Islamic Republic of
| | - Mostafa Araj-Khodaei
- Neurosciences Research Center (NSRC), Tabriz University of Medical Sciences ,Tabriz, Iran, Iran, Islamic Republic of
| | - Manouchehr S Vafaee
- Center of Neuroscience, University of Copenhagen, Copenhagen, Denmark, Denmark
| | - Dean F Wong
- Section of Nuclear Medicine, Department of Radiology and Radiological Science, Johns Hopkins Medical, United States
| | - Albert Gjedde
- Center of Neuroscience, University of Copenhagen, Copenhagen, Denmark, Denmark
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Pak K, Kim J, Kim K, Kim SJ, Kim IJ. Sleep and Neuroimaging. Nucl Med Mol Imaging 2020; 54:98-104. [PMID: 32377261 PMCID: PMC7198660 DOI: 10.1007/s13139-020-00636-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Revised: 01/06/2020] [Accepted: 02/27/2020] [Indexed: 10/24/2022] Open
Abstract
We spend about one-third of our lives either sleeping or attempting to sleep. Therefore, the socioeconomic implications of sleep disorders may be higher than expected. However, the fundamental mechanisms and functions of sleep are not yet fully understood. Neuroimaging has been utilized to reveal the connectivity between sleep and the brain, which is associated with the physiology of sleep. Positron emission tomography (PET) and single-photon emission computed tomography (SPECT) imaging studies have become increasingly common in sleep research. Recently, significant progress has been made in understanding the physiology of sleep through neuroimaging and the use of various radiopharmaceuticals, as the sleep-wake cycle is regulated by multiple neurotransmitters, including dopamine, adenosine, glutamate, and others. In addition, the characteristics of rapid eye and non-rapid eye movement sleep have been investigated by measuring cerebral glucose metabolism. The physiology of sleep has been investigated using PET to study glymphatic function as a means to clear the amyloid burden. However, the basic mechanisms and functions of sleep are not yet fully understood. Further studies are needed to investigate the effects and consequences of chronic sleep deprivation, and the relevance of sleep to other diseases.
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Affiliation(s)
- Kyoungjune Pak
- Department of Nuclear Medicine and Biomedical Research Institute, Pusan National University Hospital and School of Medicine, Pusan National University, Busan, Republic of Korea
| | - Jiyoung Kim
- Department of Neurology and Biomedical Research Institute, Pusan National University Hospital, Busan, Republic of Korea
| | - Keunyoung Kim
- Department of Nuclear Medicine and Biomedical Research Institute, Pusan National University Hospital and School of Medicine, Pusan National University, Busan, Republic of Korea
| | - Seong Jang Kim
- Department of Nuclear Medicine, Pusan National University Yangsan Hospital, Yangsan, Republic of Korea
| | - In Joo Kim
- Department of Nuclear Medicine and Biomedical Research Institute, Pusan National University Hospital and School of Medicine, Pusan National University, Busan, Republic of Korea
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Winterdahl M, Noer O, Orlowski D, Schacht AC, Jakobsen S, Alstrup AKO, Gjedde A, Landau AM. Sucrose intake lowers μ-opioid and dopamine D2/3 receptor availability in porcine brain. Sci Rep 2019; 9:16918. [PMID: 31729425 PMCID: PMC6858372 DOI: 10.1038/s41598-019-53430-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Accepted: 10/31/2019] [Indexed: 12/26/2022] Open
Abstract
Excessive sucrose consumption elicits addiction-like craving that may underpin the obesity epidemic. Opioids and dopamine mediate the rewarding effects of drugs of abuse, and of natural rewards from stimuli such as palatable food. We investigated the effects of sucrose using PET imaging with [11C]carfentanil (μ-opioid receptor agonist) and [11C]raclopride (dopamine D2/3 receptor antagonist) in seven female anesthetized Göttingen minipigs. We then gave minipigs access to sucrose solution for one hour on 12 consecutive days and performed imaging again 24 hours after the final sucrose access. In a smaller sample of five minipigs, we performed an additional [11C]carfentanil PET session after the first sucrose exposure. We calculated voxel-wise binding potentials (BPND) using the cerebellum as a region of non-displaceable binding, analyzed differences with statistical non-parametric mapping, and performed a regional analysis. After 12 days of sucrose access, BPND of both tracers had declined significantly in striatum, nucleus accumbens, thalamus, amygdala, cingulate cortex and prefrontal cortex, consistent with down-regulation of receptor densities. After a single exposure to sucrose, we found decreased binding of [11C]carfentanil in nucleus accumbens and cingulate cortex, consistent with opioid release. The lower availability of opioid and dopamine receptors may explain the addictive potential associated with intake of sucrose.
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Affiliation(s)
- Michael Winterdahl
- Department of Nuclear Medicine and PET Center, Aarhus University, Aarhus, Denmark
| | - Ove Noer
- Department of Nuclear Medicine and PET Center, Aarhus University, Aarhus, Denmark
| | - Dariusz Orlowski
- Department of Neurosurgery and CENSE, Aarhus University Hospital, Aarhus, Denmark
| | - Anna C Schacht
- Department of Nuclear Medicine and PET Center, Aarhus University, Aarhus, Denmark
| | - Steen Jakobsen
- Department of Nuclear Medicine and PET Center, Aarhus University, Aarhus, Denmark
| | - Aage K O Alstrup
- Department of Nuclear Medicine and PET Center, Aarhus University, Aarhus, Denmark
| | - Albert Gjedde
- Department of Nuclear Medicine and PET Center, Aarhus University, Aarhus, Denmark.,Department of Nuclear Medicine, University of Southern Denmark & Odense University Hospital, Odense, Denmark.,Department of Neuroscience, University of Copenhagen, Copenhagen, Denmark.,Department of Neurology and Neurosurgery, McGill University, Montreal, Canada
| | - Anne M Landau
- Department of Nuclear Medicine and PET Center, Aarhus University, Aarhus, Denmark. .,Translational Neuropsychiatry Unit, Aarhus University, Aarhus, Denmark.
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Hansson AC, Gründer G, Hirth N, Noori HR, Spanagel R, Sommer WH. Dopamine and opioid systems adaptation in alcoholism revisited: Convergent evidence from positron emission tomography and postmortem studies. Neurosci Biobehav Rev 2019; 106:141-164. [DOI: 10.1016/j.neubiorev.2018.09.010] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 09/08/2018] [Accepted: 09/14/2018] [Indexed: 12/20/2022]
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Landau AM, Alstrup AKO, Noer O, Winterdahl M, Audrain H, Møller A, Videbech P, Wegener G, Gjedde A, Doudet DJ. Electroconvulsive stimulation differentially affects [ 11C]MDL100,907 binding to cortical and subcortical 5HT 2A receptors in porcine brain. J Psychopharmacol 2019; 33:714-721. [PMID: 30887871 DOI: 10.1177/0269881119836212] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Electroconvulsive therapy is an effective therapy of depression. We hypothesized that the beneficial effects are mediated partly by decreased serotonin receptor availability in the cortex. AIMS We used positron emission tomography with the serotonin 5HT2A receptor radioligand [11C]MDL100,907 to determine serotonin receptor availability in response to electroconvulsive stimulation (ECS). METHODS Seven Göttingen minipigs were deeply anaesthetized and imaged at baseline before the onset of ECS, and at 1-2 and 8-10 days after the end of a clinical course of ECS, consisting of 10 sessions over 3.5 weeks, and post-ECS values were compared to baseline. One additional minipig was anaesthetized over 10 sessions without ECS, as a control. We analysed images with the Ichise model for binding in cortex and hippocampus, followed by whole-brain analysis by statistical non-parametric mapping. RESULTS We found significantly increased binding potential of [11C]MDL100,907 in the cortex and hippocampus 1-2 days after ECS, consistent with increased serotonin receptor availability compared to baseline. By 8-10 days after the final ECS, the average tracer binding had returned towards baseline. However, we also found significantly decreased tracer binding in the subcortical regions of olfactory bulb, pons, thalamus and striatum. CONCLUSIONS With ECS, minipigs, unlike primates but like rodents, have higher availability at cortical and hippocampal 5HT2A receptors. Decreased tracer binding is consistent with reduced serotonin receptor availability as a differential effect of ECS on 5HT2A receptors in subcortical regions of minipig brain.
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Affiliation(s)
- Anne M Landau
- 1 Translational Neuropsychiatry Unit, Aarhus University, Aarhus, Denmark.,2 Department of Nuclear Medicine and PET Centre, Aarhus University and Hospital, Aarhus, Denmark
| | | | - Ove Noer
- 2 Department of Nuclear Medicine and PET Centre, Aarhus University and Hospital, Aarhus, Denmark
| | - Michael Winterdahl
- 2 Department of Nuclear Medicine and PET Centre, Aarhus University and Hospital, Aarhus, Denmark
| | - Hélène Audrain
- 2 Department of Nuclear Medicine and PET Centre, Aarhus University and Hospital, Aarhus, Denmark
| | - Arne Møller
- 2 Department of Nuclear Medicine and PET Centre, Aarhus University and Hospital, Aarhus, Denmark.,3 Center of Functionally Integrative Neuroscience, Aarhus University, Aarhus, Denmark
| | - Poul Videbech
- 4 Centre of Mental Health, Glostrup & University of Copenhagen, Copenhagen, Denmark
| | - Gregers Wegener
- 1 Translational Neuropsychiatry Unit, Aarhus University, Aarhus, Denmark
| | - Albert Gjedde
- 2 Department of Nuclear Medicine and PET Centre, Aarhus University and Hospital, Aarhus, Denmark.,5 Department of Nuclear Medicine, University of Southern Denmark & Odense University Hospital, Odense, Denmark.,6 Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
| | - Doris J Doudet
- 7 Department of Medicine/Neurology, University of British Columbia, Vancouver, BC, Canada
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10
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Are dopamine receptor and transporter changes in Rett syndrome reflected in Mecp2-deficient mice? Exp Neurol 2018; 307:74-81. [PMID: 29782864 DOI: 10.1016/j.expneurol.2018.05.019] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Revised: 04/27/2018] [Accepted: 05/17/2018] [Indexed: 11/20/2022]
Abstract
We tested the claim that the dopaminergic dysfunction of Rett Syndrome (RTT) also occurs in Mecp2-deficient mice that serve as a model of the syndrome. We used positron emission tomography (PET) to image dopamine D2 receptors (D2R) and transporters (DAT) in women with RTT and in Mecp2-deficient mice, and D1R and D2R density was measured in postmortem human tissue by autoradiography. Results showed 1) significantly reduced D2R density in the striatum of women with RTT compared to control subjects. 2) PET imaging of mouse striatum similarly demonstrated significant reductions in D2R density of 7-10 week-old hemizygous (Mecp2-null) and heterozygous (HET) mice compared to wild type (WT) mice. With age, the density of D2R declined in WT mice but not HET mice. 3) In contrast, postmortem autoradiography revealed no group differences in the density of D1R and D2R in the caudate and putamen of RTT versus normal control subjects. 4) In humans and in the mouse model, PET revealed only marginal group differences in DAT. The results confirm that dopaminergic dysfunction in RTT is also present in Mecp2-deficient mice and that reductions in D2R more likely explain the impaired ambulation and progressive rigidity observed rather than alterations in DAT.
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11
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Wong DF, Kuwabara H, Horti AG, Roberts JM, Nandi A, Cascella N, Brasic J, Weerts EM, Kitzmiller K, Phan JA, Gapasin L, Sawa A, Valentine H, Wand G, Mishra C, George N, McDonald M, Lesniak W, Holt DP, Azad BB, Dannals RF, Kem W, Freedman R, Gjedde A. Brain PET Imaging of α7-nAChR with [18F]ASEM: Reproducibility, Occupancy, Receptor Density, and Changes in Schizophrenia. Int J Neuropsychopharmacol 2018; 21. [PMID: 29522184 PMCID: PMC6030963 DOI: 10.1093/ijnp/pyy021] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND The α7 nicotinic acetylcholine receptor increasingly has been implicated in normal brain physiology, as well as in neuropsychiatric disorders. The highly cortical distribution of α7 nicotinic acetylcholine receptor suggests a role in cognition. METHODS We expanded the first-in-human PET imaging of α7 nicotinic acetylcholine receptor with [18F]ASEM from 5 to 21 healthy nonsmoking volunteers and added a feasibility study in 6 male patients with schizophrenia. Study aims included: (1) confirmation of test-retest reproducibility of [18F]ASEM binding, (2) demonstration of specificity by competition with DMXB-A, an α7 nicotinic acetylcholine receptor partial agonist, (3) estimation of [18F]ASEM binding potentials and α7 nicotinic acetylcholine receptor density in vivo in humans, and (4) demonstrating the feasibility of studying α7 nicotinic acetylcholine receptor as a target for schizophrenia. RESULTS Test-retest PET confirmed reproducibility (>90%) (variability ≤7%) of [18F]ASEM volume of distribution (VT) estimates in healthy volunteers. Repeated sessions of PET in 5 healthy subjects included baseline and effect of inhibition after oral administration of 150 mg DMXB-A. From reduction of binding potentials, we estimated the dose-dependent occupancy of α7 nicotinic acetylcholine receptor by DMXB-A at 17% to 49% for plasma concentrations at 60 to 200 nM DMXB-A. In agreement with evidence postmortem, α7 nicotinic acetylcholine receptor density averaged 0.67 to 0.82 nM and inhibitor affinity constant averaged 170 to 385 nM. Median VT in a feasibility study of 6 patients with schizophrenia was lower than in healthy volunteers in cingulate cortex, frontal cortex, and hippocampus (P = 0.02, corrected for multiple comparions, Mann-Whitney test). CONCLUSIONS The current results confirm the reproducibility of [18F]ASEM VT estimates and the specificity of the tracer for α7 nicotinic acetylcholine receptor. Preliminary findings from our feasibility study of [18F]ASEM binding in patients with schizophrenia are suggestive and provide guidance for future studies with more subjects.
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Affiliation(s)
- Dean F Wong
- Russell H. Morgan Department of Radiology and Radiological Sciences, Baltimore, Maryland,Department of Psychiatry and Behavioral Sciences, Baltimore, Maryland,Solomon Snyder Department of Neuroscience, Baltimore, Maryland,Department of Neurology, Baltimore, Maryland,Johns Hopkins University School of Medicine, Baltimore, Maryland,Correspondence: Dean F. Wong, MD, PhD, Radiology, Nuclear Medicine, Johns Hopkins Medical Institutions, JHOC Room 3244, Baltimore, MD ()
| | - Hiroto Kuwabara
- Russell H. Morgan Department of Radiology and Radiological Sciences, Baltimore, Maryland
| | - Andrew G Horti
- Russell H. Morgan Department of Radiology and Radiological Sciences, Baltimore, Maryland
| | - Joshua M Roberts
- Russell H. Morgan Department of Radiology and Radiological Sciences, Baltimore, Maryland
| | - Ayon Nandi
- Russell H. Morgan Department of Radiology and Radiological Sciences, Baltimore, Maryland
| | - Nicola Cascella
- Russell H. Morgan Department of Radiology and Radiological Sciences, Baltimore, Maryland,Sheppard-Pratt Hospital, Baltimore, Maryland
| | - James Brasic
- Russell H. Morgan Department of Radiology and Radiological Sciences, Baltimore, Maryland
| | - Elise M Weerts
- Department of Psychiatry and Behavioral Sciences, Baltimore, Maryland
| | - Kelly Kitzmiller
- Russell H. Morgan Department of Radiology and Radiological Sciences, Baltimore, Maryland
| | - Jenny A Phan
- Russell H. Morgan Department of Radiology and Radiological Sciences, Baltimore, Maryland,Department of Biomedicine, Aarhus University, Aarhus, Denmark,Department of Nuclear Medicine and PET Centre, Aarhus University Hospital, Aarhus, Denmark
| | - Lorena Gapasin
- Russell H. Morgan Department of Radiology and Radiological Sciences, Baltimore, Maryland
| | - Akira Sawa
- Department of Psychiatry and Behavioral Sciences, Baltimore, Maryland
| | - Heather Valentine
- Russell H. Morgan Department of Radiology and Radiological Sciences, Baltimore, Maryland
| | - Gary Wand
- Department of Psychiatry and Behavioral Sciences, Baltimore, Maryland,Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Chakradhar Mishra
- Russell H. Morgan Department of Radiology and Radiological Sciences, Baltimore, Maryland
| | - Noble George
- Russell H. Morgan Department of Radiology and Radiological Sciences, Baltimore, Maryland
| | - Michael McDonald
- Russell H. Morgan Department of Radiology and Radiological Sciences, Baltimore, Maryland
| | - Wojtek Lesniak
- Russell H. Morgan Department of Radiology and Radiological Sciences, Baltimore, Maryland
| | - Daniel P Holt
- Russell H. Morgan Department of Radiology and Radiological Sciences, Baltimore, Maryland
| | - Babak B Azad
- Russell H. Morgan Department of Radiology and Radiological Sciences, Baltimore, Maryland
| | - Robert F Dannals
- Russell H. Morgan Department of Radiology and Radiological Sciences, Baltimore, Maryland
| | - William Kem
- Russell H. Morgan Department of Radiology and Radiological Sciences, Baltimore, Maryland,Department of Pharmacology and Therapeutics, University of Florida, Gainesville, Florida
| | - Robert Freedman
- Department of Psychiatry, University of Colorado, Aurora, Colorado
| | - Albert Gjedde
- Russell H. Morgan Department of Radiology and Radiological Sciences, Baltimore, Maryland,Department of Nuclear Medicine, University of Southern Denmark, Odense, Denmark
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12
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Chagraoui A, Boukhzar L, Thibaut F, Anouar Y, Maltête D. The pathophysiological mechanisms of motivational deficits in Parkinson's disease. Prog Neuropsychopharmacol Biol Psychiatry 2018; 81:138-152. [PMID: 29097256 DOI: 10.1016/j.pnpbp.2017.10.022] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Revised: 09/21/2017] [Accepted: 10/30/2017] [Indexed: 12/23/2022]
Abstract
Parkinson's disease (PD) is a progressive degenerative disorder that leads to disabling motor symptoms and a wide variety of neuropsychiatric symptoms. Apathy is the most common psychiatric disorder in the early stages of untreated PD and can be defined as a hypodopaminergic syndrome, which also includes anxiety and depression. Apathy is also considered the core feature of the parkinsonian triad (apathy, anxiety and depression) of behavioural non-motor signs, including a motivational deficit. Moreover, apathy is recognised as a distinct chronic neuropsychiatric behavioural disorder based on specific diagnostic criteria. Given the prevalence of apathy in approximately 40% of the general Parkinson's disease population, this appears to be a contributing factor to dementia in PD; also, apathy symptoms are factors that potentially contribute to morbidity, leading to a major impairment of health-related quality of life, thus stressing the importance of understanding the pathophysiology of this disease. Several studies have clearly established a prominent role for DA-mediated signals in PD apathy. However, synergistic interaction between dopaminergic impairment resulting from the neurodegenerative process and deep brain stimulation of the subthalamic nucleus may cause or exacerbate apathy. Furthermore, serotoninergic mechanism signalling is also likely to be of importance in this pathophysiology.
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Affiliation(s)
- A Chagraoui
- Normandie Univ, UNIROUEN, INSERM, U1239, CHU Rouen, Neuronal and Neuroendocrine Differentiation and Communication Laboratory, Institute for Research and Innovation in Biomedicine of Normandy (IRIB), Rouen, France.; Department of Medical Biochemistry, Rouen University Hospital, Rouen, France.
| | - L Boukhzar
- Normandie Univ, UNIROUEN, INSERM, U1239, CHU Rouen, Neuronal and Neuroendocrine Differentiation and Communication Laboratory, Institute for Research and Innovation in Biomedicine of Normandy (IRIB), Rouen, France
| | - F Thibaut
- Department of Psychiatry, University Hospital Cochin (site Tarnier), University of Paris-Descartes and INSERM U 894 Laboratory of Psychiatry and Neurosciences, Paris, France
| | - Y Anouar
- Normandie Univ, UNIROUEN, INSERM, U1239, CHU Rouen, Neuronal and Neuroendocrine Differentiation and Communication Laboratory, Institute for Research and Innovation in Biomedicine of Normandy (IRIB), Rouen, France
| | - D Maltête
- Department of Neurology, Rouen University Hospital, Rouen, France
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13
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Radioligand binding analysis of α 2 adrenoceptors with [ 11C]yohimbine in brain in vivo: Extended Inhibition Plot correction for plasma protein binding. Sci Rep 2017; 7:15979. [PMID: 29167492 PMCID: PMC5700124 DOI: 10.1038/s41598-017-16020-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Accepted: 10/23/2017] [Indexed: 11/23/2022] Open
Abstract
We describe a novel method of kinetic analysis of radioligand binding to neuroreceptors in brain in vivo, here applied to noradrenaline receptors in rat brain. The method uses positron emission tomography (PET) of [11C]yohimbine binding in brain to quantify the density and affinity of α2 adrenoceptors under condition of changing radioligand binding to plasma proteins. We obtained dynamic PET recordings from brain of Spraque Dawley rats at baseline, followed by pharmacological challenge with unlabeled yohimbine (0.3 mg/kg). The challenge with unlabeled ligand failed to diminish radioligand accumulation in brain tissue, due to the blocking of radioligand binding to plasma proteins that elevated the free fractions of the radioligand in plasma. We devised a method that graphically resolved the masking of unlabeled ligand binding by the increase of radioligand free fractions in plasma. The Extended Inhibition Plot introduced here yielded an estimate of the volume of distribution of non-displaceable ligand in brain tissue that increased with the increase of the free fraction of the radioligand in plasma. The resulting binding potentials of the radioligand declined by 50–60% in the presence of unlabeled ligand. The kinetic unmasking of inhibited binding reflected in the increase of the reference volume of distribution yielded estimates of receptor saturation consistent with the binding of unlabeled ligand.
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14
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Phan JA, Stokholm K, Zareba-Paslawska J, Jakobsen S, Vang K, Gjedde A, Landau AM, Romero-Ramos M. Early synaptic dysfunction induced by α-synuclein in a rat model of Parkinson's disease. Sci Rep 2017; 7:6363. [PMID: 28743955 PMCID: PMC5526979 DOI: 10.1038/s41598-017-06724-9] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 06/15/2017] [Indexed: 02/08/2023] Open
Abstract
Evidence suggests that synapses are affected first in Parkinson’s disease (PD). Here, we tested the claim that pathological accumulation of α-synuclein, and subsequent synaptic disruption, occur in absence of dopaminergic neuron loss in PD. We determined early synaptic changes in rats that overexpress human α-synuclein by local injection of viral-vectors in midbrain. We aimed to achieve α-synuclein levels sufficient to induce terminal pathology without significant loss of nigral neurons. We tested synaptic disruption in vivo by analyzing motor defects and binding of a positron emission tomography (PET) radioligand to the vesicular monoamine transporter 2, (VMAT2), [11C]dihydrotetrabenazine (DTBZ). Animals overexpressing α-synuclein had progressive motor impairment and, 12 weeks post-surgery, showed asymmetric in vivo striatal DTBZ binding. The PET images matched ligand binding in post-mortem tissue, and histological markers of dopaminergic integrity. Histology confirmed the absence of nigral cell death with concomitant significant loss of striatal terminals. Progressive aggregation of proteinase-K resistant and Ser129-phosphorylated α-synuclein was observed in dopaminergic terminals, in dystrophic swellings that resembled axonal spheroids and contained mitochondria and vesicular proteins. In conclusion, pathological α-synuclein in nigro-striatal axonal terminals leads to early axonal pathology, synaptic disruption, dysfunction of dopaminergic neurotransmission, motor impairment, and measurable change of VMAT2 in the absence of cell loss.
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Affiliation(s)
- Jenny-Ann Phan
- Department of Biomedicine, NEURODIN AU IDEAS Center, Aarhus University, Wilhelm Meyers Allé 4, bldg. 1242, Aarhus C, 8000, Denmark.,Department of Nuclear Medicine and PET Centre, Aarhus University and Hospital, Norrebrogade 44, bldg. 10G, Aarhus C, 8000, Denmark
| | - Kathrine Stokholm
- Department of Biomedicine, NEURODIN AU IDEAS Center, Aarhus University, Wilhelm Meyers Allé 4, bldg. 1242, Aarhus C, 8000, Denmark.,Department of Nuclear Medicine and PET Centre, Aarhus University and Hospital, Norrebrogade 44, bldg. 10G, Aarhus C, 8000, Denmark
| | - Justyna Zareba-Paslawska
- Department of Biomedicine, NEURODIN AU IDEAS Center, Aarhus University, Wilhelm Meyers Allé 4, bldg. 1242, Aarhus C, 8000, Denmark
| | - Steen Jakobsen
- Department of Nuclear Medicine and PET Centre, Aarhus University and Hospital, Norrebrogade 44, bldg. 10G, Aarhus C, 8000, Denmark
| | - Kim Vang
- Department of Nuclear Medicine and PET Centre, Aarhus University and Hospital, Norrebrogade 44, bldg. 10G, Aarhus C, 8000, Denmark
| | - Albert Gjedde
- Department of Neuroscience and Pharmacology, University of Copenhagen, Blegdamsvej 3, Copenhagen, 2200, Denmark.,Center of Neuroscience, University of Copenhagen, Copenhagen, Denmark.,Dept of Radiology & Radiological Science, Johns Hopkins University, Baltimore, MD, USA.,Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada.,Neurosciences Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.,Department of Clinical Medicine, University of Southern Denmark, Odense, Denmark
| | - Anne M Landau
- Department of Nuclear Medicine and PET Centre, Aarhus University and Hospital, Norrebrogade 44, bldg. 10G, Aarhus C, 8000, Denmark. .,Translational Neuropsychiatry Unit, Aarhus University, Skovagervej 2, Risskov, 8240, Denmark.
| | - Marina Romero-Ramos
- Department of Biomedicine, NEURODIN AU IDEAS Center, Aarhus University, Wilhelm Meyers Allé 4, bldg. 1242, Aarhus C, 8000, Denmark.
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15
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Caravaggio F, Borlido C, Wilson A, Graff-Guerrero A. Examining endogenous dopamine in treated schizophrenia using [¹¹C]-(+)-PHNO positron emission tomography: A pilot study. Clin Chim Acta 2015; 449:60-2. [PMID: 25814099 DOI: 10.1016/j.cca.2015.03.020] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2015] [Accepted: 03/16/2015] [Indexed: 10/23/2022]
Abstract
BACKGROUND Using positron emission tomography (PET) it is possible to estimate endogenous dopamine (DA) occupying D2/3 receptors (D2/3R) in the living human brain. Persons with schizophrenia (SZ) (previously medicated and naïve) have increased endogenous DA occupying D2/3R in the caudate. It is unknown whether currently medicated patients demonstrate increased DA levels at D2/3R. Moreover, DA levels have not been estimated in SZ using agonist radiotracers, which may offer a more sensitive quantification over antagonists. METHODS Using the agonist radiotracer [(11)C]-(+)-PHNO, DA levels were estimated at D2/3R (ΔBP(ND)) in three patients with SZ (male, mean age=30±16). Patients were currently being treated long-term with Olanzapine (147±88 nmol/L). Results were compared to ten healthy controls (HCs). RESULTS Medicated persons with SZ had greater ΔBP(ND) in the left caudate (U=2, Z=-2.20, p=.03) and right putamen (U=2, Z=-2.20, p=.03). No differences were observed in the ventral striatum or globus pallidus. CONCLUSIONS It is possible to estimate endogenous DA at D2/3R in SZ patients currently taking antipsychotics. Despite medication, patients continue to have increased endogenous DA at D2/3R. This lends more biological support to the clinical observation that relapses in symptoms can occur in the face of complete antipsychotic discontinuation. Future studies with larger samples are warranted.
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Affiliation(s)
- Fernando Caravaggio
- Research Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, Ontario M5T 1R8, Canada; Institute of Medical Science, University of Toronto, 2374 Medical Sciences Building, 1 King's College Circle, Toronto, Ontario M5S 1A8, Canada
| | - Carol Borlido
- Research Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, Ontario M5T 1R8, Canada
| | - Alan Wilson
- Research Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, Ontario M5T 1R8, Canada; Institute of Medical Science, University of Toronto, 2374 Medical Sciences Building, 1 King's College Circle, Toronto, Ontario M5S 1A8, Canada; Department of Psychiatry, University of Toronto, 250 College Street, Toronto, Ontario M5T 1R8, Canada
| | - Ariel Graff-Guerrero
- Research Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, Ontario M5T 1R8, Canada; Institute of Medical Science, University of Toronto, 2374 Medical Sciences Building, 1 King's College Circle, Toronto, Ontario M5S 1A8, Canada; Department of Psychiatry, University of Toronto, 250 College Street, Toronto, Ontario M5T 1R8, Canada.
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16
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Nahimi A, Jakobsen S, Munk OL, Vang K, Phan JA, Rodell A, Gjedde A. Mapping α2 adrenoceptors of the human brain with 11C-yohimbine. J Nucl Med 2015; 56:392-8. [PMID: 25635132 DOI: 10.2967/jnumed.114.145565] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
UNLABELLED A previous study from this laboratory suggested that (11)C-yohimbine, a selective α2-adrenoceptor antagonist, is an appropriate ligand for PET of α2 adrenoceptors that passes readily from blood to brain tissue in pigs but not in rodents. To test usefulness in humans, we determined blood-brain clearances, volumes of distribution, and receptor availability by means of PET with (11)C-yohimbine in healthy male adults. METHODS We recorded the distribution of (11)C-yohimbine with 90-min dynamic PET and sampled arterial blood to measure intact (11)C-yohimbine in plasma. For analysis, we coregistered PET images to individual MR images and automatically identified 27 volumes of interest. We used 1-tissue-compartment graphical analysis with 6 linearized solutions of the fundamental binding equation, with the metabolite-corrected arterial plasma curves as input function, to estimate the kinetic parameters of (11)C-yohimbine. With the lowest steady-state distribution volume (VT), determined in the corpus callosum, we calculated the binding potential (receptor availability) of the radioligand in other regions. RESULTS The linear regressions yielded similar estimates of the kinetic parameters. The cortical values of VT ranged from 0.82 mL cm(-3) in the right frontal cortex to 0.46 mL cm(-3) in the corpus callosum, with intermediate VT values in subcortical structures. Binding potentials averaged 0.6-0.8 in the cortex and 0.2-0.5 in subcortical regions. CONCLUSION The maps of (11)C-yohimbine binding to α2 adrenoceptors in human brain had the highest values in cortical areas and hippocampus, with moderate values in subcortical structures, as found also in vitro. The results confirm the usefulness of the tracer (11)C-yohimbine for mapping α2 adrenoceptors in human brain in vivo.
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Affiliation(s)
- Adjmal Nahimi
- Department of Nuclear Medicine and PET Centre, Aarhus University Hospitals, Aarhus, Denmark
| | - Steen Jakobsen
- Department of Nuclear Medicine and PET Centre, Aarhus University Hospitals, Aarhus, Denmark
| | - Ole L Munk
- Department of Nuclear Medicine and PET Centre, Aarhus University Hospitals, Aarhus, Denmark
| | - Kim Vang
- Department of Nuclear Medicine and PET Centre, Aarhus University Hospitals, Aarhus, Denmark
| | - Jenny A Phan
- Department of Nuclear Medicine and PET Centre, Aarhus University Hospitals, Aarhus, Denmark
| | - Anders Rodell
- Department of Nuclear Medicine and PET Centre, Aarhus University Hospitals, Aarhus, Denmark
| | - Albert Gjedde
- Department of Nuclear Medicine and PET Centre, Aarhus University Hospitals, Aarhus, Denmark Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen, Denmark Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, Maryland; and Department of Neurology, McGill University, Montreal, Quebec, Canada
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17
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Caravaggio F, Nakajima S, Borlido C, Remington G, Gerretsen P, Wilson A, Houle S, Menon M, Mamo D, Graff-Guerrero A. Estimating endogenous dopamine levels at D2 and D3 receptors in humans using the agonist radiotracer [(11)C]-(+)-PHNO. Neuropsychopharmacology 2014; 39:2769-76. [PMID: 24874713 PMCID: PMC4200487 DOI: 10.1038/npp.2014.125] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Revised: 04/15/2014] [Accepted: 05/05/2014] [Indexed: 11/10/2022]
Abstract
Using positron emission tomography (PET) and an acute dopamine depletion challenge it is possible to estimate endogenous dopamine levels occupying dopamine D2/3 receptors (D2/3R) in humans in vivo. Our group has developed [(11)C]-(+)-PHNO, the first agonist radiotracer with preferential in vivo affinity for D3R. Thus, the use of [(11)C]-(+)-PHNO offers the novel possibility of (i) estimating in vivo endogenous dopamine levels at D2/3R using an agonist radiotracer, and (ii) estimating endogenous dopamine levels at D3R in extrastriatal regions such as the substantia nigra, hypothalamus, and ventral pallidum. Ten healthy participants underwent a [(11)C]-(+)-PHNO PET scan under baseline conditions and another under acute endogenous dopamine depletion achieved via oral administration of alpha-methyl-para-tyrosine (64 mg/kg). [(11)C]-(+)-PHNO binding was sensitive to acute dopamine depletion, allowing in vivo estimates of endogenous dopamine in D2R-rich regions (caudate and putamen), mixed D2/3R-rich regions (ventral striatum and globus pallidus), and extrastriatal D3R-rich regions (hypothalamus and ventral pallidum). Dopamine depletion decreased self-reported vigor, which was correlated with the reduction in dopamine levels in the globus pallidus. [(11)C]-(+)-PHNO is a suitable radiotracer for use in estimating endogenous dopamine levels at D2R and D3R in neuropsychiatric populations.
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Affiliation(s)
- Fernando Caravaggio
- Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, ON, Canada,Institute of Medical Science, University of Toronto, Toronto, ON, Canada
| | - Shinichiro Nakajima
- Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, ON, Canada,Department of Psychiatry, University of Toronto, Toronto, ON, Canada
| | - Carol Borlido
- Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, ON, Canada
| | - Gary Remington
- Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, ON, Canada,Institute of Medical Science, University of Toronto, Toronto, ON, Canada,Department of Psychiatry, University of Toronto, Toronto, ON, Canada
| | - Philip Gerretsen
- Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, ON, Canada,Institute of Medical Science, University of Toronto, Toronto, ON, Canada,Department of Psychiatry, University of Toronto, Toronto, ON, Canada
| | - Alan Wilson
- Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, ON, Canada,Institute of Medical Science, University of Toronto, Toronto, ON, Canada,Department of Psychiatry, University of Toronto, Toronto, ON, Canada
| | - Sylvain Houle
- Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, ON, Canada,Department of Psychiatry, University of Toronto, Toronto, ON, Canada
| | - Mahesh Menon
- Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, ON, Canada,Department of Psychiatry, University of Toronto, Toronto, ON, Canada
| | - David Mamo
- Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, ON, Canada,Department of Psychiatry, University of Toronto, Toronto, ON, Canada
| | - Ariel Graff-Guerrero
- Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, ON, Canada,Institute of Medical Science, University of Toronto, Toronto, ON, Canada,Department of Psychiatry, University of Toronto, Toronto, ON, Canada,Research Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, ON, Canada M5T 1R8. Tel: +416 535 8501x4834, Fax: +1 416 979 3855, E-mail:
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18
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del Campo N, Fryer TD, Hong YT, Smith R, Brichard L, Acosta-Cabronero J, Chamberlain SR, Tait R, Izquierdo D, Regenthal R, Dowson J, Suckling J, Baron JC, Aigbirhio FI, Robbins TW, Sahakian BJ, Müller U. A positron emission tomography study of nigro-striatal dopaminergic mechanisms underlying attention: implications for ADHD and its treatment. ACTA ACUST UNITED AC 2013; 136:3252-70. [PMID: 24163364 PMCID: PMC4125626 DOI: 10.1093/brain/awt263] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Through the combined use of 18F-fallypride positron emission tomography and magnetic resonance imaging this study examined the neural mechanisms underlying the attentional deficits associated with attention deficit/hyperactivity disorder and their potential reversal with a single therapeutic dose of methylphenidate. Sixteen adult patients with attention deficit/hyperactivity disorder and 16 matched healthy control subjects were positron emission tomography and magnetic resonance imaging scanned and tested on a computerized sustained attention task after oral methylphenidate (0.5 mg/kg) and placebo administration in a within-subject, double-blind, cross-over design. Although patients with attention deficit/hyperactivity disorder as a group showed significant attentional deficits and reduced grey matter volume in fronto-striato-cerebellar and limbic networks, they had equivalent D2/D3 receptor availability and equivalent increases in endogenous dopamine after methylphenidate treatment to that observed in healthy control subjects. However, poor attentional performers drawn from both the attention deficit/hyperactivity disorder and the control groups had significantly reduced left caudate dopamine activity. Methylphenidate significantly increased dopamine levels in all nigro-striatal regions, thereby normalizing dopamine levels in the left caudate in low performers. Behaviourally, methylphenidate improved sustained attention in a baseline performance-dependent manner, irrespective of diagnosis. This finding was accompanied by an equally performance-dependent effect of the drug on dopamine release in the midbrain, whereby low performers showed reduced dopamine release in this region. Collectively, these findings support a dimensional model of attentional deficits and underlying nigro-striatal dopaminergic mechanisms of attention deficit/hyperactivity disorder that extends into the healthy population. Moreover, they confer midbrain dopamine autoreceptors a hitherto neglected role in the therapeutic effects of oral methylphenidate in attention deficit/hyperactivity disorder. The absence of significant case–control differences in D2/D3 receptor availability (despite the observed relationships between dopamine activity and attention) suggests that dopamine dysregulation per se is unlikely to be the primary cause underlying attention deficit/hyperactivity disorder pathology in adults. This conclusion is reinforced by evidence of neuroanatomical changes in the same set of patients with attention deficit/hyperactivity disorder.
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Affiliation(s)
- Natalia del Campo
- 1 Department of Psychiatry, University of Cambridge, Addenbrooke's Hospital, Cambridge CB2 0QQ, UK
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Linnet J. The Iowa Gambling Task and the three fallacies of dopamine in gambling disorder. Front Psychol 2013; 4:709. [PMID: 24115941 PMCID: PMC3792697 DOI: 10.3389/fpsyg.2013.00709] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Accepted: 09/17/2013] [Indexed: 12/05/2022] Open
Abstract
Gambling disorder sufferers prefer immediately larger rewards despite long term losses on the Iowa Gambling Task (IGT), and these impairments are associated with dopamine dysfunctions. Dopamine is a neurotransmitter linked with temporal and structural dysfunctions in substance use disorder, which has supported the idea of impaired decision-making and dopamine dysfunctions in gambling disorder. However, evidence from substance use disorders cannot be directly transferred to gambling disorder. This article focuses on three hypotheses of dopamine dysfunctions in gambling disorder, which appear to be “fallacies,” i.e., have not been supported in a series of positron emission tomography (PET) studies. The first “fallacy” suggests that gambling disorder sufferers have lower dopamine receptor availability, as seen in substance use disorders. However, no evidence supported this hypothesis. The second “fallacy” suggests that maladaptive decision-making in gambling disorder is associated with higher dopamine release during gambling. No evidence supported the hypothesis, and the literature on substance use disorders offers limited support for this hypothesis. The third “fallacy” suggests that maladaptive decision-making in gambling disorder is associated with higher dopamine release during winning. The evidence did not support this hypothesis either. Instead, dopaminergic coding of reward prediction and uncertainty might better account for dopamine dysfunctions in gambling disorder. Studies of reward prediction and reward uncertainty show a sustained dopamine response toward stimuli with maximum uncertainty, which may explain the continued dopamine release and gambling despite losses in gambling disorder. The findings from the studies presented here are consistent with the notion of dopaminergic dysfunctions of reward prediction and reward uncertainty signals in gambling disorder.
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Affiliation(s)
- Jakob Linnet
- Research Clinic on Gambling Disorders, Aarhus University Hospital Aarhus, Denmark ; Clinical Department, Center of Functionally Integrative Neuroscience, Medical School of Aarhus University Aarhus, Denmark ; Division on Addiction, Cambridge Health Alliance Cambridge, MA, USA ; Department of Psychiatry, Harvard Medical School, Harvard University Cambridge, MA, USA
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Callesen MB, Hansen KV, Gjedde A, Linnet J, Møller A. Dopaminergic and clinical correlates of pathological gambling in Parkinson's disease: a case report. Front Behav Neurosci 2013; 7:95. [PMID: 23908610 PMCID: PMC3725950 DOI: 10.3389/fnbeh.2013.00095] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Accepted: 07/13/2013] [Indexed: 11/13/2022] Open
Abstract
Dopaminergic medication for motor symptoms in Parkinson's disease (PD) recently has been linked with impulse control disorders, including pathological gambling (PG), which affects up to 8% of patients. PG often is considered a behavioral addiction associated with disinhibition, risky decision-making, and altered striatal dopaminergic neurotransmission. Using [(11)C]raclopride with positron emission tomography, we assessed dopaminergic neurotransmission during Iowa Gambling Task performance. Here we present data from a single patient with PD and concomitant PG. We noted a marked decrease in [(11)C]raclopride binding in the left ventral striatum upon gambling, indicating a gambling-induced dopamine release. The results imply that PG in PD is associated with a high dose of dopaminergic medication, pronounced motor symptomatology, young age at disease onset, high propensity for sensation seeking, and risky decision-making. Overall, the findings are consistent with the hypothesis of medication-related PG in PD and underscore the importance of taking clinical variables, such as age and personality, into account when patients with PD are medicated, to reduce the risk of PG.
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Affiliation(s)
- Mette Buhl Callesen
- Department of Nuclear Medicine and PET-Centre, Aarhus University Hospital, Aarhus, Denmark
- Centre of Functionally Integrative Neuroscience, Aarhus University, Aarhus, Denmark
| | - K. V. Hansen
- Department of Nuclear Medicine and PET-Centre, Aarhus University Hospital, Aarhus, Denmark
| | - A. Gjedde
- Department of Nuclear Medicine and PET-Centre, Aarhus University Hospital, Aarhus, Denmark
- Centre of Functionally Integrative Neuroscience, Aarhus University, Aarhus, Denmark
- Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - J. Linnet
- Centre of Functionally Integrative Neuroscience, Aarhus University, Aarhus, Denmark
- Research Clinic on Gambling Disorders, Aarhus University Hospital, Aarhus, Denmark
| | - A. Møller
- Department of Nuclear Medicine and PET-Centre, Aarhus University Hospital, Aarhus, Denmark
- Centre of Functionally Integrative Neuroscience, Aarhus University, Aarhus, Denmark
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Smith DF, Jakobsen S. Molecular Neurobiology of Depression: PET Findings on the Elusive Correlation with Symptom Severity. Front Psychiatry 2013; 4:8. [PMID: 23459670 PMCID: PMC3586775 DOI: 10.3389/fpsyt.2013.00008] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2012] [Accepted: 02/11/2013] [Indexed: 01/08/2023] Open
Abstract
Molecular mechanisms in the brain are assumed to cause the symptoms and severity of neuropsychiatric disorders. This review concerns the elusive nature of relationships between the severity of depressive disorders and neuromolecular processes studied by positron emission tomography (PET). Recent PET studies of human depression have focused on serotonergic, dopaminergic, muscarinic, nicotinic, and GABAergic receptors, as well as central processes dependent on monoamine oxidase, phosphodiesterase type 4, amyloid plaques, neurofibrillar tangles, and P-glycoprotein. We find that reliable causal links between neuromolecular mechanisms and relief from depressive disorders have yet to be convincingly demonstrated. This situation may contribute to the currently limited use of PET for exploring the neuropathways that are currently viewed as being responsible for beneficial effects of antidepressant treatment regimes.
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Affiliation(s)
- Donald F Smith
- Center for Psychiatric Research, Psychiatric Hospital of Aarhus University Risskov, Denmark
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Linnet J, Mouridsen K, Peterson E, Møller A, Doudet DJ, Gjedde A. Striatal dopamine release codes uncertainty in pathological gambling. Psychiatry Res 2012; 204:55-60. [PMID: 22889563 DOI: 10.1016/j.pscychresns.2012.04.012] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2011] [Revised: 01/26/2012] [Accepted: 04/24/2012] [Indexed: 12/13/2022]
Abstract
Two mechanisms of midbrain and striatal dopaminergic projections may be involved in pathological gambling: hypersensitivity to reward and sustained activation toward uncertainty. The midbrain-striatal dopamine system distinctly codes reward and uncertainty, where dopaminergic activation is a linear function of expected reward and an inverse U-shaped function of uncertainty. In this study, we investigated the dopaminergic coding of reward and uncertainty in 18 pathological gambling sufferers and 16 healthy controls. We used positron emission tomography (PET) with the tracer [(11)C]raclopride to measure dopamine release, and we used performance on the Iowa Gambling Task (IGT) to determine overall reward and uncertainty. We hypothesized that we would find a linear function between dopamine release and IGT performance, if dopamine release coded reward in pathological gambling. If, on the other hand, dopamine release coded uncertainty, we would find an inversely U-shaped function. The data supported an inverse U-shaped relation between striatal dopamine release and IGT performance if the pathological gambling group, but not in the healthy control group. These results are consistent with the hypothesis of dopaminergic sensitivity toward uncertainty, and suggest that dopaminergic sensitivity to uncertainty is pronounced in pathological gambling, but not among non-gambling healthy controls. The findings have implications for understanding dopamine dysfunctions in pathological gambling and addictive behaviors.
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Affiliation(s)
- Jakob Linnet
- Research Clinic on Gambling Disorders, Aarhus University Hospital, Nørrebrogade 44, Building 30, DK-8000 Aarhus C, Denmark.
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Methylphenidate-elicited dopamine increases in ventral striatum are associated with long-term symptom improvement in adults with attention deficit hyperactivity disorder. J Neurosci 2012; 32:841-9. [PMID: 22262882 DOI: 10.1523/jneurosci.4461-11.2012] [Citation(s) in RCA: 153] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Stimulant medications, such as methylphenidate, which are effective treatments for attention deficit hyperactivity disorder (ADHD), enhance brain dopamine signaling. However, the relationship between regional brain dopamine enhancement and treatment response has not been evaluated. Here, we assessed whether the dopamine increases elicited by methylphenidate are associated with long-term clinical response. We used a prospective design to study 20 treatment-naive adults with ADHD who were evaluated before treatment initiation and after 12 months of clinical treatment with a titrated regimen of oral methylphenidate. Methylphenidate-induced dopamine changes were evaluated with positron emission tomography and [(11)C]raclopride (D(2)/D(3) receptor radioligand sensitive to competition with endogenous dopamine). Clinical responses were assessed using the Conners' Adult ADHD Rating Scale and revealed a significant reduction in symptoms of inattention and hyperactivity with long-term methylphenidate treatment. A challenge dose of 0.5 mg/kg intravenous methylphenidate significantly increased dopamine in striatum (assessed as decreases in D(2)/D(3) receptor availability). In the ventral striatum, these dopamine increases were associated with the reductions in ratings of symptoms of inattention with clinical treatment. Statistical parametric mapping additionally showed dopamine increases in prefrontal and temporal cortices with intravenous methylphenidate that were also associated with decreases in symptoms of inattention. Our findings indicate that dopamine enhancement in ventral striatum (the brain region involved with reward and motivation) was associated with therapeutic response to methylphenidate, further corroborating the relevance of the dopamine reward/motivation circuitry in ADHD. It also provides preliminary evidence that methylphenidate-elicited dopamine increases in prefrontal and temporal cortices may also contribute to the clinical response.
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Abstract
Positron emission tomography, single-photon emission tomography, and magnetic resonance spectroscopy (MRS) are powerful tools for the monitoring of diverse neurochemical functions. Neuroimaging studies targeting neurotransmitter systems in autism have provided clues about how differences in development of these systems might lead to new intervention approaches. Direct measurement of diverse neurochemicals with MRS provides unique probes of neuronal integrity in vivo. Future directions include the combination of imaging modalities made possible by advances in software and hardware. Many tracers have not been applied in autism, and new molecules and signaling pathways might be targeted as genes associated with autism are identified.
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Affiliation(s)
- Diane C Chugani
- Carman and Ann Adams Department of Pediatrics, Division of Clinical Pharmacology and Toxicology, Children's Hospital of Michigan, Detroit Medical Center, Wayne State University School of Medicine, 3901 Beaubien Boulevard, Detroit, MI 48201 USA.
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Nahimi A, Høltzermann M, Landau AM, Simonsen M, Jakobsen S, Alstrup AKO, Vang K, Møller A, Wegener G, Gjedde A, Doudet DJ. Serotonergic modulation of receptor occupancy in rats treated with l-DOPA after unilateral 6-OHDA lesioning. J Neurochem 2012; 120:806-17. [DOI: 10.1111/j.1471-4159.2011.07598.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Volkow ND, Wang GJ, Newcorn JH, Kollins SH, Wigal TL, Telang F, Fowler JS, Goldstein RZ, Klein N, Logan J, Wong C, Swanson JM. Motivation deficit in ADHD is associated with dysfunction of the dopamine reward pathway. Mol Psychiatry 2011; 16:1147-54. [PMID: 20856250 PMCID: PMC3010326 DOI: 10.1038/mp.2010.97] [Citation(s) in RCA: 245] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Attention-deficit hyperactivity disorder (ADHD) is typically characterized as a disorder of inattention and hyperactivity/impulsivity but there is increasing evidence of deficits in motivation. Using positron emission tomography (PET), we showed decreased function in the brain dopamine reward pathway in adults with ADHD, which, we hypothesized, could underlie the motivation deficits in this disorder. To evaluate this hypothesis, we performed secondary analyses to assess the correlation between the PET measures of dopamine D2/D3 receptor and dopamine transporter availability (obtained with [(11)C]raclopride and [(11)C]cocaine, respectively) in the dopamine reward pathway (midbrain and nucleus accumbens) and a surrogate measure of trait motivation (assessed using the Achievement scale on the Multidimensional Personality Questionnaire or MPQ) in 45 ADHD participants and 41 controls. The Achievement scale was lower in ADHD participants than in controls (11±5 vs 14±3, P<0.001) and was significantly correlated with D2/D3 receptors (accumbens: r=0.39, P<0.008; midbrain: r=0.41, P<0.005) and transporters (accumbens: r=0.35, P<0.02) in ADHD participants, but not in controls. ADHD participants also had lower values in the Constraint factor and higher values in the Negative Emotionality factor of the MPQ but did not differ in the Positive Emotionality factor-and none of these were correlated with the dopamine measures. In ADHD participants, scores in the Achievement scale were also negatively correlated with symptoms of inattention (CAARS A, E and SWAN I). These findings provide evidence that disruption of the dopamine reward pathway is associated with motivation deficits in ADHD adults, which may contribute to attention deficits and supports the use of therapeutic interventions to enhance motivation in ADHD.
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Affiliation(s)
- Nora D. Volkow
- National Institute on Drug Abuse, Bethesda, MD 20892,Laboratory of Neuroimaging, National Institute on Alcohol Abuse and Alcoholism, Bethesda, MD 20892
| | - Gene-Jack Wang
- Medical and Chemistry Departments, Brookhaven National Laboratory, Upton, NY 11973,Department of Psychiatry, Mount Sinai Medical Center, New York, NY 10029
| | - Jeffrey H. Newcorn
- Department of Psychiatry, Mount Sinai Medical Center, New York, NY 10029
| | - Scott H. Kollins
- Department of Psychiatry, Department of Psychiatry, Duke University Medical Center, Durham, NC 27701
| | - Tim L. Wigal
- Child Development Center, University of California, Irvine, CA 92612
| | - Frank Telang
- Laboratory of Neuroimaging, National Institute on Alcohol Abuse and Alcoholism, Bethesda, MD 20892
| | - Joanna S. Fowler
- Medical and Chemistry Departments, Brookhaven National Laboratory, Upton, NY 11973,Department of Psychiatry, Mount Sinai Medical Center, New York, NY 10029
| | - Rita Z. Goldstein
- Medical and Chemistry Departments, Brookhaven National Laboratory, Upton, NY 11973
| | - Nelly Klein
- Medical and Chemistry Departments, Brookhaven National Laboratory, Upton, NY 11973
| | - Jean Logan
- Medical and Chemistry Departments, Brookhaven National Laboratory, Upton, NY 11973
| | - Christopher Wong
- Medical and Chemistry Departments, Brookhaven National Laboratory, Upton, NY 11973
| | - James M. Swanson
- Child Development Center, University of California, Irvine, CA 92612
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Linnet J, Møller A, Peterson E, Gjedde A, Doudet D. Inverse association between dopaminergic neurotransmission and Iowa Gambling Task performance in pathological gamblers and healthy controls. Scand J Psychol 2011; 52:28-34. [PMID: 20704689 DOI: 10.1111/j.1467-9450.2010.00837.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The dopamine system is believed to affect gambling behavior in pathological gambling. Particularly, dopamine release in the ventral striatum appears to affect decision-making in the disorder. This study investigated dopamine release in the ventral striatum in relation to gambling performance on the Iowa Gambling Task (IGT) in 16 Pathological Gamblers (PG) and 14 Healthy Controls (HC). We used Positron Emission Tomography (PET) to measure the binding potential of [(11)C] raclopride to dopamine D2/3 receptors during a baseline and gambling condition. We hypothesized that decreased raclopride binding potentials in the ventral striatum during gambling (indicating dopamine release) would be associated with higher IGT performance in Healthy Controls, but lower IGT performance in Pathological Gamblers. The results showed that Pathological Gamblers with dopamine release in the ventral striatum had significantly lower IGT performance than Healthy Controls. Furthermore, dopamine release was associated with significantly higher IGT performance in Healthy Controls and significantly lower IGT performance in Pathological Gamblers. The results suggest that dopamine release is involved both in adaptive and maladaptive decision-making. These findings may contribute to a better understanding of dopaminergic dysfunctions in pathological gambling and substance related addictions.
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Affiliation(s)
- Jakob Linnet
- Center of Functionally Integrative Neuroscience, Aarhus University, Arhus University Hospital, Arhus C, Denmark.
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Linnet J, Møller A, Peterson E, Gjedde A, Doudet D. Dopamine release in ventral striatum during Iowa Gambling Task performance is associated with increased excitement levels in pathological gambling. Addiction 2011; 106:383-90. [PMID: 20883460 DOI: 10.1111/j.1360-0443.2010.03126.x] [Citation(s) in RCA: 161] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
AIMS Gambling excitement is believed to be associated with biological measures of pathological gambling. Here, we tested the hypothesis that dopamine release would be associated with increased excitement levels in Pathological Gamblers compared with Healthy Controls. DESIGN Pathological Gamblers and Healthy Controls were experimentally compared in a non-gambling (baseline) and gambling condition. MEASUREMENTS We used Positron Emission Tomography (PET) with the tracer raclopride to measure dopamine D 2/3 receptor availability in the ventral striatum during a non-gambling and gambling condition of the Iowa Gambling Task (IGT). After each condition participants rated their excitement level. SETTING Laboratory experiment. PARTICIPANTS 18 Pathological Gamblers and 16 Healthy Controls. FINDINGS Pathological Gamblers with dopamine release in the ventral striatum had significantly higher excitement levels than Healthy Controls despite lower IGT performance. No differences in excitement levels and IGT performance were found between Pathological Gamblers and Healthy Controls without dopamine release. Pathological Gamblers showed a significant correlation between dopamine release and excitement level, while no such interaction was found in Healthy Controls. CONCLUSIONS In pathological gamblers dopamine release in the ventral striatum appears to be associated with increased excitement levels despite lower IGT performance. The results might suggest a 'double deficit' function of dopamine in pathological gambling, where dopamine release reinforces maladaptive gambling through increasing excitement levels, reducing inhibition of risky decisions, or a combination of both. These findings may have implications for the understanding of dopamine in pathological gambling and other forms of addiction.
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Affiliation(s)
- Jakob Linnet
- Center of Functionally Integrative Neuroscience, Aarhus University, Aarhus, Denmark.
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Linnet J, Peterson E, Doudet DJ, Gjedde A, Møller A. Dopamine release in ventral striatum of pathological gamblers losing money. Acta Psychiatr Scand 2010; 122:326-33. [PMID: 20712823 DOI: 10.1111/j.1600-0447.2010.01591.x] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To investigate dopaminergic neurotransmission in relation to monetary reward and punishment in pathological gambling. Pathological gamblers (PG) often continue gambling despite losses, known as 'chasing one's losses'. We therefore hypothesized that losing money would be associated with increased dopamine release in the ventral striatum of PG compared with healthy controls (HC). METHOD We used Positron Emission Tomography (PET) with [(11)C]raclopride to measure dopamine release in the ventral striatum of 16 PG and 15 HC playing the Iowa Gambling Task (IGT). RESULTS PG who lost money had significantly increased dopamine release in the left ventral striatum compared with HC. PG and HC who won money did not differ in dopamine release. CONCLUSION Our findings suggest a dopaminergic basis of monetary losses in pathological gambling, which might explain loss-chasing behavior. The findings may have implications for the understanding of dopamine dysfunctions and impaired decision-making in pathological gambling and substance-related addictions.
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Affiliation(s)
- Jakob Linnet
- Center of Functionally Integrative Neuroscience, Aarhus University, Aarhus, Denmark.
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Thobois S, Ardouin C, Lhommée E, Klinger H, Lagrange C, Xie J, Fraix V, Coelho Braga MC, Hassani R, Kistner A, Juphard A, Seigneuret E, Chabardes S, Mertens P, Polo G, Reilhac A, Costes N, LeBars D, Savasta M, Tremblay L, Quesada JL, Bosson JL, Benabid AL, Broussolle E, Pollak P, Krack P. Non-motor dopamine withdrawal syndrome after surgery for Parkinson's disease: predictors and underlying mesolimbic denervation. Brain 2010; 133:1111-27. [PMID: 20237128 DOI: 10.1093/brain/awq032] [Citation(s) in RCA: 344] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Apathy has been reported to occur after subthalamic nucleus stimulation, a treatment of motor complications in advanced Parkinson's disease. We carried out a prospective study of the occurrence of apathy and associated symptoms, predictors and mechanisms in the year following subthalamic stimulation. Dopamine agonist drugs were discontinued immediately after surgery and levodopa was markedly reduced within 2 weeks. Apathy and depression were assessed monthly, using the Starkstein apathy scale and the Beck Depression Inventory. Dopamine agonists were re-introduced if patients developed apathy or depression. Preoperative non-motor fluctuations were evaluated using the Ardouin Scale. Depression, apathy and anxiety were evaluated both on and off levodopa. Analysis of predictors of apathy was performed using a Cox proportional hazard model. Twelve patients who developed apathy and a control group of 13 patients who did not underwent [11C]-raclopride positron emission tomography scanning before and after oral intake of methylphenidate. In 63 patients with Parkinson's disease treated with subthalamic stimulation, dopaminergic treatment was decreased by 82% after surgery. Apathy occurred after a mean of 4.7 (3.3-8.2) months in 34 patients and was reversible in half of these by the 12-month follow-up. Seventeen patients developed transient depression after 5.7 (4.7-9.3) months and these fell into the apathy group with one single exception. At baseline, fluctuations in depression, apathy and anxiety scores were greater in the group with apathy. Fluctuations in apathy, depression and anxiety ratings during a baseline levodopa challenge were also significant predictors of postoperative apathy in univariate analysis, but not motor and cognitive states or the level of reduction of dopaminergic medication. The multivariate model identified non-motor fluctuations in everyday life and anxiety score during the baseline levodopa challenge as two independent significant predictors of postoperative apathy. Without methylphenidate, [11C]-raclopride binding potential values were greater in apathetic patients bilaterally in the orbitofrontal, dorsolateral prefrontal, posterior cingulate and temporal cortices, left striatum and right amygdala, reflecting greater dopamine D2/D3 receptor density and/or reduced synaptic dopamine level in these areas. The variations of [11C]-raclopride binding potential values induced by methylphenidate were greater in non-apathetic patients in the left orbitofrontal cortex, dorsolateral prefrontal cortex, thalamus and internal globus pallidus and bilaterally in the anterior and posterior cingulate cortices, consistent with a more important capacity to release dopamine. Non-motor fluctuations are related to mesolimbic dopaminergic denervation. Apathy, depression and anxiety can occur after surgery as a delayed dopamine withdrawal syndrome. A varying extent of mesolimbic dopaminergic denervation and differences in dopaminergic treatment largely determine mood, anxiety and motivation in patients with Parkinson's disease, contributing to different non-motor phenotypes.
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Affiliation(s)
- Stéphane Thobois
- Universitée Lyon I, Hospices Civils de Lyon, Hôpital Neurologique Pierre Wertheimer, Service de Neurologie C, Lyon, France
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Inverted-U-shaped correlation between dopamine receptor availability in striatum and sensation seeking. Proc Natl Acad Sci U S A 2010; 107:3870-5. [PMID: 20133675 DOI: 10.1073/pnas.0912319107] [Citation(s) in RCA: 112] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Sensation seeking is a core personality trait that declines with age in both men and women, as do also both density and availability of the dopamine D(2/3) receptors in striatum and cortical regions. In contrast, novelty seeking at a given age relates inversely to dopamine receptor availability. The simplest explanation of these findings is an inverted-U-shaped correlation between ratings of sensation seeking on the Zuckerman scale and dopamine D(2/3) receptor availability. To test the claim of an inverted-U-shaped relation between ratings of the sensation-seeking personality and measures of dopamine receptor availability, we used PET to record [(11)C]raclopride binding in striatum of 18 healthy men. Here we report that an inverted-U shape significantly matched the receptor availability as a function of the Zuckerman score, with maximum binding potentials observed in the midrange of the scale. The inverted-U shape is consistent with a negative correlation between sensation seeking and the reactivity ("gain") of dopaminergic neurotransmission to dopamine. The correlation reflects Zuckerman scores that are linearly linked to dopamine receptor densities in the striatum but nonlinearly linked to dopamine concentrations. Higher dopamine occupancy and dopamine concentrations explain the motivation that drives afflicted individuals to seek sensations, in agreement with reduced protection against addictive behavior that is characteristic of individuals with low binding potentials.
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Volkow ND, Wang GJ, Kollins SH, Wigal TL, Newcorn JH, Telang F, Fowler JS, Zhu W, Logan J, Ma Y, Pradhan K, Wong C, Swanson JM. Evaluating dopamine reward pathway in ADHD: clinical implications. JAMA 2009; 302:1084-91. [PMID: 19738093 PMCID: PMC2958516 DOI: 10.1001/jama.2009.1308] [Citation(s) in RCA: 389] [Impact Index Per Article: 25.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
CONTEXT Attention-deficit/hyperactivity disorder (ADHD)--characterized by symptoms of inattention and hyperactivity-impulsivity--is the most prevalent childhood psychiatric disorder that frequently persists into adulthood, and there is increasing evidence of reward-motivation deficits in this disorder. OBJECTIVE To evaluate biological bases that might underlie a reward/motivation deficit by imaging key components of the brain dopamine reward pathway (mesoaccumbens). DESIGN, SETTING, AND PARTICIPANTS We used positron emission tomography to measure dopamine synaptic markers (transporters and D(2)/D(3) receptors) in 53 nonmedicated adults with ADHD and 44 healthy controls between 2001-2009 at Brookhaven National Laboratory. MAIN OUTCOME MEASURES We measured specific binding of positron emission tomographic radioligands for dopamine transporters (DAT) using [(11)C]cocaine and for D(2)/D(3) receptors using [(11)C]raclopride, quantified as binding potential (distribution volume ratio -1). RESULTS For both ligands, statistical parametric mapping showed that specific binding was lower in ADHD than in controls (threshold for significance set at P < .005) in regions of the dopamine reward pathway in the left side of the brain. Region-of-interest analyses corroborated these findings. The mean (95% confidence interval [CI] of mean difference) for DAT in the nucleus accumbens for controls was 0.71 vs 0.63 for those with ADHD (95% CI, 0.03-0.13, P = .004) and in the midbrain for controls was 0.16 vs 0.09 for those with ADHD (95% CI, 0.03-0.12; P < or = .001); for D(2)/D(3) receptors, the mean accumbens for controls was 2.85 vs 2.68 for those with ADHD (95% CI, 0.06-0.30, P = .004); and in the midbrain, it was for controls 0.28 vs 0.18 for those with ADHD (95% CI, 0.02-0.17, P = .01). The analysis also corroborated differences in the left caudate: the mean DAT for controls was 0.66 vs 0.53 for those with ADHD (95% CI, 0.04-0.22; P = .003) and the mean D(2)/D(3) for controls was 2.80 vs 2.47 for those with ADHD (95% CI, 0.10-0.56; P = .005) and differences in D(2)/D(3) in the hypothalamic region, with controls having a mean of 0.12 vs 0.05 for those with ADHD (95% CI, 0.02-0.12; P = .004). Ratings of attention correlated with D(2)/D(3) in the accumbens (r = 0.35; 95% CI, 0.15-0.52; P = .001), midbrain (r = 0.35; 95% CI, 0.14-0.52; P = .001), caudate (r = 0.32; 95% CI, 0.11-0.50; P = .003), and hypothalamic (r = 0.31; CI, 0.10-0.49; P = .003) regions and with DAT in the midbrain (r = 0.37; 95% CI, 0.16-0.53; P < or = .001). CONCLUSION A reduction in dopamine synaptic markers associated with symptoms of inattention was shown in the dopamine reward pathway of participants with ADHD.
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Affiliation(s)
- Nora D Volkow
- National Institute on Drug Abuse, 6001 Executive Blvd, Room 5274, MSC 9581, Bethesda, MD 20892, USA.
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Volkow ND, Fowler JS, Logan J, Alexoff D, Zhu W, Telang F, Wang GJ, Jayne M, Hooker JM, Wong C, Hubbard B, Carter P, Warner D, King P, Shea C, Xu Y, Muench L, Apelskog-Torres K. Effects of modafinil on dopamine and dopamine transporters in the male human brain: clinical implications. JAMA 2009; 301:1148-54. [PMID: 19293415 PMCID: PMC2696807 DOI: 10.1001/jama.2009.351] [Citation(s) in RCA: 366] [Impact Index Per Article: 24.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
CONTEXT Modafinil, a wake-promoting drug used to treat narcolepsy, is increasingly being used as a cognitive enhancer. Although initially launched as distinct from stimulants that increase extracellular dopamine by targeting dopamine transporters, recent preclinical studies suggest otherwise. OBJECTIVE To measure the acute effects of modafinil at doses used therapeutically (200 mg and 400 mg given orally) on extracellular dopamine and on dopamine transporters in the male human brain. DESIGN, SETTING, AND PARTICIPANTS Positron emission tomography with [(11)C]raclopride (D(2)/D(3) radioligand sensitive to changes in endogenous dopamine) and [(11)C]cocaine (dopamine transporter radioligand) was used to measure the effects of modafinil on extracellular dopamine and on dopamine transporters in 10 healthy male participants. The study took place over an 8-month period (2007-2008) at Brookhaven National Laboratory. MAIN OUTCOME MEASURES Primary outcomes were changes in dopamine D(2)/D(3) receptor and dopamine transporter availability (measured by changes in binding potential) after modafinil when compared with after placebo. RESULTS Modafinil decreased mean (SD) [(11)C]raclopride binding potential in caudate (6.1% [6.5%]; 95% confidence interval [CI], 1.5% to 10.8%; P = .02), putamen (6.7% [4.9%]; 95% CI, 3.2% to 10.3%; P = .002), and nucleus accumbens (19.4% [20%]; 95% CI, 5% to 35%; P = .02), reflecting increases in extracellular dopamine. Modafinil also decreased [(11)C]cocaine binding potential in caudate (53.8% [13.8%]; 95% CI, 43.9% to 63.6%; P < .001), putamen (47.2% [11.4%]; 95% CI, 39.1% to 55.4%; P < .001), and nucleus accumbens (39.3% [10%]; 95% CI, 30% to 49%; P = .001), reflecting occupancy of dopamine transporters. CONCLUSIONS In this pilot study, modafinil blocked dopamine transporters and increased dopamine in the human brain (including the nucleus accumbens). Because drugs that increase dopamine in the nucleus accumbens have the potential for abuse, and considering the increasing use of modafinil, these results highlight the need for heightened awareness for potential abuse of and dependence on modafinil in vulnerable populations.
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Affiliation(s)
- Nora D Volkow
- National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland, USA.
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Hyperstimulation of striatal D2 receptors with sleep deprivation: Implications for cognitive impairment. Neuroimage 2009; 45:1232-40. [PMID: 19349237 DOI: 10.1016/j.neuroimage.2009.01.003] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2008] [Revised: 12/30/2008] [Accepted: 01/05/2009] [Indexed: 11/24/2022] Open
Abstract
Sleep deprivation interferes with cognitive performance but the mechanisms are poorly understood. We recently reported that one night of sleep deprivation increased dopamine in striatum (measured with [(11)C]raclopride, a PET radiotracer that competes with endogenous dopamine for binding to D2 receptors) and that these increases were associated with impaired performance in a visual attention task. To better understand this association here we evaluate the relationship between changes in striatal dopamine (measured as changes in D2 receptor availability using PET and [(11)C]raclopride) and changes in brain activation to a visual attention task (measured with BOLD and fMRI) when performed during sleep deprivation versus during rested wakefulness. We find that sleep induced changes in striatal dopamine were associated with changes in cortical brain regions modulated by dopamine (attenuated deactivation of anterior cingulate gyrus and insula) but also in regions that are not recognized targets of dopaminergic modulation (attenuated activation of inferior occipital cortex and cerebellum). Moreover, the increases in striatal dopamine as well as its associated regional activation and deactivation patterns correlated negatively with performance accuracy. These findings therefore suggest that hyperstimulation of D2 receptors in striatum may contribute to the impairment in visual attention during sleep deprivation. Thus, while dopamine increases in prefrontal regions (including stimulation of D1 receptors) may facilitate attention our findings suggest that hyperstimulation of D2 receptors in striatum may impair it. Alternatively, these associations may reflect a compensatory striatal dopamine response (to maintain arousal) that is superimposed on a larger response to sleep deprivation.
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Sleep deprivation decreases binding of [11C]raclopride to dopamine D2/D3 receptors in the human brain. J Neurosci 2008; 28:8454-61. [PMID: 18716203 DOI: 10.1523/jneurosci.1443-08.2008] [Citation(s) in RCA: 142] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Sleep deprivation did not affect dopamine transporters (target for most wake-promoting medications) and thus dopamine increases are likely to reflect increases in dopamine cell firing and/or release rather than decreases in dopamine reuptake. Because dopamine-enhancing drugs increase wakefulness, we postulate that dopamine increases after sleep deprivation is a mechanism by which the brain maintains arousal as the drive to sleep increases but one that is insufficient to counteract behavioral and cognitive impairment. Sleep deprivation can markedly impair human performance contributing to accidents and poor productivity. The mechanisms underlying this impairment are not well understood, but brain dopamine systems have been implicated. Here, we test whether one night of sleep deprivation changes dopamine brain activity. We studied 15 healthy subjects using positron emission tomography and [11C]raclopride (dopamine D2/D3 receptor radioligand) and [11C]cocaine (dopamine transporter radioligand). Subjects were tested twice: after one night of rested sleep and after one night of sleep deprivation. The specific binding of [11C]raclopride in the striatum and thalamus were significantly reduced after sleep deprivation and the magnitude of this reduction correlated with increases in fatigue (tiredness and sleepiness) and with deterioration in cognitive performance (visual attention and working memory). In contrast, sleep deprivation did not affect the specific binding of [11C]cocaine in the striatum. Because [11C]raclopride competes with endogenous dopamine for binding to D2/D3 receptors, we interpret the decreases in binding to reflect dopamine increases with sleep deprivation. However, we cannot rule out the possibility that decreased [11C]raclopride binding reflects decreases in receptor levels or affinity. Sleep deprivation did not affect dopamine transporters (target for most wake-promoting medications) and thus dopamine increases are likely to reflect increases in dopamine cell firing and/or release rather than decreases in dopamine reuptake. Because dopamine-enhancing drugs increase wakefulness, we postulate that dopamine increases after sleep deprivation is a mechanism by which the brain maintains arousal as the drive to sleep increases but one that is insufficient to counteract behavioral and cognitive impairment.
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Brust P, Patt JT, Deuther-Conrad W, Becker G, Patt M, Schildan A, Sorger D, Kendziorra K, Meyer P, Steinbach J, Sabri O. In vivo measurement of nicotinic acetylcholine receptors with [18F]norchloro-fluoro-homoepibatidine. Synapse 2008; 62:205-18. [PMID: 18088060 DOI: 10.1002/syn.20480] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Functional changes of nicotinic acetylcholine receptors (nAChR) are important during age-related neuronal degeneration. Recent studies demonstrate the applicability of the nAChR ligand 2-[(18)F]F-A-85380 for neuroimaging of patients with dementias. However, its binding kinetics demands a 7-h acquisition time limiting its practicality for clinical PET studies. Thus, the authors developed [(18)F]norchloro-fluoro-homoepibatidine ([(18)F]NCFHEB) for nAChR imaging. The kinetics of the two enantiomers of [(18)F]NCFHEB were compared with 2-[(18)F]F-A85380 in porcine brain to evaluate their potential for human neuroimaging. Twenty-four juvenile female pigs were studied with PET using [(18)F]NCFHEB. Nine animals received an additional i.v. injection (1 mg/kg) of the nAChR agonist A81418 before radiotracer administration followed by infusion (2 mg/kg/7h) thereafter. Several compartment models were applied for quantification. (-)- and (+)-[(18)F]NCFHEB showed a twofold to threefold higher brain uptake than 2-[(18)F]F-A-85380. All three radiotracers displayed spatially heterogeneous binding kinetics in regions with high, moderate, or low specific binding. The equilibrium of specific binding of (-)-[(18)F]NCFHEB was reached earlier than that of (+)-[(18)F]NCFHEB or 2-[(18)F]F-A85380. Continuous administration of the nAChR agonist A81418 inhibited the specific binding of (-)- and (+)-[(18)F]NCFHEB but not of 2-[(18)F]F-A85380. The peripheral metabolism of (+)-[(18)F]NCFHEB proceeded somewhat slower than that of the other radiotracers. Both enantiomers of [(18)F]NCFHEB are appropriate radiotracers for neuroimaging of nAChR in pigs. Their binding profile in vivo appears to be more selective than that of 2-[(18)F]F-A85380. (-)-[(18)F]NCFHEB offers a faster equilibrium of specific binding than 2-[(18)F]F-A85380.
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Affiliation(s)
- Peter Brust
- Department of Radiopharmacy, Institute of Interdisciplinary Isotope Research, Permoserstrasse 15, Leipzig, Germany.
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Profound decreases in dopamine release in striatum in detoxified alcoholics: possible orbitofrontal involvement. J Neurosci 2007; 27:12700-6. [PMID: 18003850 DOI: 10.1523/jneurosci.3371-07.2007] [Citation(s) in RCA: 323] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The value of rewards (natural rewards and drugs) is associated with dopamine increases in the nucleus accumbens and varies as a function of context. The prefrontal cortex has been implicated in the context dependency of rewards and in the fixated high value that drugs have in addiction, although the mechanisms are not properly understood. Here we test the hypothesis that the prefrontal cortex regulates the value of rewards by modulating dopamine increases in nucleus accumbens and that this regulation is disrupted in addicted subjects. We used positron emission tomography to evaluate the activity of the prefrontal cortex (measuring brain glucose metabolism with [18F]fluorodeoxyglucose) and dopamine increases (measured with [11C]raclopride, a D2/D3 receptor ligand with binding that is sensitive to endogenous dopamine) induced by the stimulant drug methylphenidate in 20 controls and 20 detoxified alcoholics, most of whom smoked. In all subjects, methylphenidate significantly increased dopamine in striatum. In ventral striatum (where the nucleus accumbens is located) and in putamen, dopamine increases were associated with the rewarding effects of methylphenidate (drug liking and high) and were profoundly attenuated in alcoholics (70 and 50% lower than controls, respectively). In controls, but not in alcoholics, metabolism in orbitofrontal cortex (region involved with salience attribution) was negatively associated with methylphenidate-induced dopamine increases in ventral striatum. These results are consistent with the hypothesis that the orbitofrontal cortex modulates the value of rewards by regulating the magnitude of dopamine increases in the ventral striatum and that disruption of this regulation may underlie the decreased sensitivity to rewards in addicted subjects.
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Volkow ND, Wang GJ, Telang F, Fowler JS, Logan J, Childress AR, Jayne M, Ma Y, Wong C. Dopamine increases in striatum do not elicit craving in cocaine abusers unless they are coupled with cocaine cues. Neuroimage 2007; 39:1266-73. [PMID: 18024160 DOI: 10.1016/j.neuroimage.2007.09.059] [Citation(s) in RCA: 123] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2007] [Revised: 09/17/2007] [Accepted: 09/25/2007] [Indexed: 11/26/2022] Open
Abstract
Imaging studies have shown an association between dopamine increases in striatum and cue induced craving in cocaine abusers. However, the extent to which dopamine increases reflect a primary rather than a secondary response to the cues remains unclear. Here we evaluated the extent to which dopamine increases by themselves can induce craving in cocaine abusers. Using PET and [(11)C]raclopride (D2 receptor radioligand sensitive to competition with endogenous dopamine) we show that in cocaine abusers (n=20) oral methylphenidate (20 mg), which significantly increased dopamine in striatum, did not induce craving unless subjects were concomitantly exposed to cocaine cues (video scenes of subjects self-administering cocaine). This suggests that dopamine increases associated with conditioned cues are not primary responses but reflect downstream stimulation of dopamine cells (presumably glutamatergic afferents from prefrontal cortex and/or amygdala). Inasmuch as afferent stimulation of dopamine neurons results in phasic cell firing these findings suggest that "fast" dopamine increases, in contrast to the "slow" dopamine increases as achieved when using oral methylphenidate (mimicking tonic dopamine cell firing), are required for cues to trigger craving. The fact that methylphenidate induced craving only when given with the cocaine cues highlights the context dependency of methylphenidate's effects and suggests that its use for the treatment of ADHD subjects with co-morbid drug abuse should not increase craving.
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Affiliation(s)
- Nora D Volkow
- National Institute on Drug Abuse, Bethesda MD 20892, USA; National Institute on Alcohol Abuse and Alcoholism, Bethesda, MD 20892, USA.
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Oswald LM, Wong DF, Zhou Y, Kumar A, Brasic J, Alexander M, Ye W, Kuwabara H, Hilton J, Wand GS. Impulsivity and chronic stress are associated with amphetamine-induced striatal dopamine release. Neuroimage 2007; 36:153-66. [PMID: 17433881 DOI: 10.1016/j.neuroimage.2007.01.055] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2006] [Revised: 01/17/2007] [Accepted: 01/19/2007] [Indexed: 11/16/2022] Open
Abstract
A challenging question that continues to plague the field of addiction is why some individuals are more vulnerable for substance use disorders than others. Several important risk factors for substance abuse have been identified in clinical studies, including trait impulsivity and environmental stress. However, the neurobiological mechanisms that underlie the relationships remain poorly understood. The purpose of this study was to examine associations among impulsivity, stress, and striatal dopamine (DA) responses to amphetamine (AMPH) in humans. Forty healthy M, F adults, ages 18-29 years, completed self-report measures of trait impulsivity, life events stress, and perceived stress. Subjects subsequently underwent two consecutive 90-min positron emission tomography (PET) studies with high specific activity [11C]raclopride. The first scan was preceded by an intravenous injection of saline; the second was preceded by 0.3 mg/kg AMPH. Findings showed that high impulsivity was associated with blunted right ventral striatal DA release. However, effects were modified by a significant interaction with life events stress. Dopamine release was greater in low vs. high impulsivity subjects under conditions of low or moderate stress. Under conditions of high stress, both groups had low DA release. Subjects with high impulsivity reported more pleasant effects with AMPH than subjects with low impulsivity. In contrast, stress was negatively associated with pleasant drug effects. No associations were observed between impulsivity or stress and cortisol responses to AMPH. The findings are consistent with notions that blunted DA responses represent an endophenotype for substance use disorders.
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Affiliation(s)
- Lynn M Oswald
- Department of Psychiatry and Behavioral Sciences, The Johns Hopkins University School of Medicine, MD 21205, USA
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Wong DF, Kuwabara H, Schretlen DJ, Bonson KR, Zhou Y, Nandi A, Brasić JR, Kimes AS, Maris MA, Kumar A, Contoreggi C, Links J, Ernst M, Rousset O, Zukin S, Grace AA, Lee JS, Rohde C, Jasinski DR, Gjedde A, London ED. Increased occupancy of dopamine receptors in human striatum during cue-elicited cocaine craving. Neuropsychopharmacology 2006; 31:2716-27. [PMID: 16971900 DOI: 10.1038/sj.npp.1301194] [Citation(s) in RCA: 246] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
In all, 19 research subjects, with current histories of frequent cocaine use, were exposed to cocaine-related cues to elicit drug craving. We measured the change of occupancy of dopamine at D2-like receptors with positron emission tomography (PET) and inferred a change of intrasynaptic dopamine (endogenous dopamine release), based on the displacement of radiotracer [(11)C]raclopride. Receptor occupancy by dopamine increased significantly in putamen of participants who reported cue-elicited craving compared to those who did not. Further, the intensity of craving was positively correlated with the increase in dopamine receptor occupancy in the putamen. These results provide direct evidence that occupancy of dopamine receptors in human dorsal striatum increased in proportion to subjective craving, presumably because of increased release of intrasynaptic dopamine.
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Affiliation(s)
- Dean F Wong
- The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD 21287-0807, USA.
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Vasdev N, Natesan S, Galineau L, Garcia A, Stableford WT, McCormick P, Seeman P, Houle S, Wilson AA. Radiosynthesis, ex vivo and in vivo evaluation of [11C]preclamol as a partial dopamine D2 agonist radioligand for positron emission tomography. Synapse 2006; 60:314-8. [PMID: 16786538 DOI: 10.1002/syn.20304] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Dopamine D2 partial agonists have been successfully used as schizophrenia therapeutics. Radiolabeled D2 partial agonists may have application in elucidating dopaminergic transmission. It was the goal of this work to radiolabel (S)-(-)propyl-3-(3-hydroxyphenyl)piperidine (preclamol; (-)3-PPP), a partial dopamine D2 agonist with carbon-11 (half-life=20.4 min) and to evaluate this novel radiopharmaceutical for dopaminergic imaging in rodent models. [11C]Preclamol was synthesized by acylation of (S)-3-(3-hydroxyphenyl)piperidine hydrochloride with [11C]propionyl chloride, followed by LiAlH4 reduction, and HPLC purification. Male Sprague-Dawley rats were injected in the tail vein with a saline solution of [11C]preclamol (1.1 mug/kg) and sacrificed at 5, 15, 30 and 60 min postinjection. Brain regions were excised, weighed, and measured for radioactivity. In vivo binding kinetics of [11C]preclamol were determined with beta-sensitive microprobes implanted into the striatum and cerebellum of an anesthetized rat. A full production of [11C]preclamol resulted in 34 mCi ready for injection (corresponding to 4% uncorrected radiochemical yield, based on starting [11C]CO2) with specific activity of 535 mCi/micromol. The total synthesis time was 45 min and resulted in chemically and radiochemically pure [11C]preclamol (>99%; n=3). High levels of radioactivity were observed in rat brain indicating good blood-brain barrier penetration of [11C]preclamol, with 0.5 to 0.7% injected dose per gram of wet tissue present in all brain regions at 5 minutes postinjection. Unfortunately, [11C]preclamol displayed minimal preferential uptake in dopaminergic brain regions. A low striatal specific binding (SB) ratio of 0.32 was determined ex vivo at 60 min postinjection and was in close agreement with the microprobe study over 60 min (peaked at 27 min postinjection; SB ratio=0.6). The binding potential value was only 0.34 over a 1 hour time course, suggesting that [11C]preclamol is not suitable for cerebral PET studies.
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Affiliation(s)
- Neil Vasdev
- PET Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada, M5T-1R8.
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Sundaram SK, Chugani HT, Chugani DC. Positron emission tomography methods with potential for increased understanding of mental retardation and developmental disabilities. ACTA ACUST UNITED AC 2005; 11:325-30. [PMID: 16240413 DOI: 10.1002/mrdd.20086] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Positron emission tomography (PET) is a technique that enables imaging of the distribution of radiolabeled tracers designed to track biochemical and molecular processes in the body after intravenous injection or inhalation. New strategies for the use of radiolabeled tracers hold potential for imaging gene expression in the brain during development and following interventions. In addition, PET may be key in identifying the physiological consequences of gene mutations associated with mental retardation. The development of high spatial resolution microPET scanners for imaging of rodents provides a means for longitudinal study of transgenic mouse models of genetic disorders associated with mental retardation. In this review, we describe PET methodology, illustrate how PET can be used to delineate biochemical changes during brain development, and provide examples of how PET has been applied to study brain glucose metabolism in Rett syndrome, serotonin synthesis in autism, and GABAA receptors in Angelman's syndrome and Prader-Willi syndrome. Future application of PET scanning in the study of mental retardation might include measurements of brain protein synthesis in fragile X syndrome and tuberous sclerosis complex, two common conditions associated with mental retardation in which cellular mechanisms involve dysregulation of protein synthesis. Mental retardation results in life-long disability, and application of new PET technologies holds promise for a better understanding of the biological underpinnings of mental retardation, with the potential to uncover new treatment options.
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Affiliation(s)
- Senthil K Sundaram
- Carman and Ann Adams Department of Pediatrics, Children's Hospital of Michigan, Wayne State University School of Medicine, Detroit, Michigan 48201, USA
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