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Lopresti BJ, Royse SK, Mathis CA, Tollefson SA, Narendran R. Beyond monoamines: I. Novel targets and radiotracers for Positron emission tomography imaging in psychiatric disorders. J Neurochem 2023; 164:364-400. [PMID: 35536762 DOI: 10.1111/jnc.15615] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 04/05/2022] [Accepted: 04/06/2022] [Indexed: 10/18/2022]
Abstract
With the emergence of positron emission tomography (PET) in the late 1970s, psychiatry had access to a tool capable of non-invasive assessment of human brain function. Early applications in psychiatry focused on identifying characteristic brain blood flow and metabolic derangements using radiotracers such as [15 O]H2 O and [18 F]FDG. Despite the success of these techniques, it became apparent that more specific probes were needed to understand the neurochemical bases of psychiatric disorders. The first neurochemical PET imaging probes targeted sites of action of neuroleptic (dopamine D2 receptors) and psychoactive (serotonin receptors) drugs. Based on the centrality of monoamine dysfunction in psychiatric disorders and the measured success of monoamine-enhancing drugs in treating them, the next 30 years witnessed the development of an armamentarium of PET radiopharmaceuticals and imaging methodologies for studying monoamines. Continued development of monoamine-enhancing drugs over this time however was less successful, realizing only modest gains in efficacy and tolerability. As patent protection for many widely prescribed and profitable psychiatric drugs lapsed, drug development pipelines shifted away from monoamines in search of novel targets with the promises of improved efficacy, or abandoned altogether. Over this period, PET radiopharmaceutical development activities closely paralleled drug development priorities resulting in the development of new PET imaging agents for non-monoamine targets. Part one of this review will briefly survey novel PET imaging targets with relevance to the field of psychiatry, which include the metabotropic glutamate receptor type 5 (mGluR5), purinergic P2 X7 receptor, type 1 cannabinoid receptor (CB1 ), phosphodiesterase 10A (PDE10A), and describe radiotracers developed for these and other targets that have matured to human subject investigations. Current limitations of the targets and techniques will also be discussed.
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Affiliation(s)
- Brian J Lopresti
- Departments of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Sarah K Royse
- Departments of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Chester A Mathis
- Departments of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Savannah A Tollefson
- Departments of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Rajesh Narendran
- Departments of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.,Departments of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
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2
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Radhakrishnan R, Worhunsky PD, Zheng MQ, Najafzadeh S, Gallezot JD, Planeta B, Henry S, Nabulsi N, Ranganathan M, Skosnik PD, Pittman B, Cyril D'Souza D, Carson RE, Huang Y, Potenza MN, Matuskey D. Age, gender and body-mass-index relationships with in vivo CB 1 receptor availability in healthy humans measured with [ 11C]OMAR PET. Neuroimage 2022; 264:119674. [PMID: 36243269 DOI: 10.1016/j.neuroimage.2022.119674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 09/07/2022] [Accepted: 10/05/2022] [Indexed: 11/06/2022] Open
Abstract
Brain cannabinoid 1 receptors (CB1Rs) contribute importantly to the regulation of autonomic tone, appetite, mood and cognition. Inconsistent results have been reported from positron emission tomography (PET) studies using different radioligands to examine relationships between age, gender and body mass index (BMI) and CB1R availability in healthy individuals. In this study, we examined these variables in 58 healthy individuals (age range: 18-55 years; 44 male; BMI=27.01±5.56), the largest cohort of subjects studied to date using the CB1R PET ligand [11C]OMAR. There was a significant decline in CB1R availability (VT) with age in the pallidum, cerebellum and posterior cingulate. Adjusting for BMI, age-related decline in VT remained significant in the posterior cingulate among males, and in the cerebellum among women. CB1R availability was higher in women compared to men in the thalamus, pallidum and posterior cingulate. Adjusting for age, CB1R availability negatively correlated with BMI in women but not men. These findings differ from those reported using [11C]OMAR and other radioligands such as [18F]FMPEP-d2 and [18F]MK-9470. Although reasons for these seemingly divergent findings are unclear, the choice of PET radioligand and range of BMI in the current dataset may contribute to the observed differences. This study highlights the need for cross-validation studies using both [11C]OMAR and [18F]FMPEP-d2 within the same cohort of subjects.
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Affiliation(s)
- Rajiv Radhakrishnan
- Department of Psychiatry, Yale University School of Medicinev, New Haven, CT 06511, United States.
| | - Patrick D Worhunsky
- Department of Psychiatry, Yale University School of Medicinev, New Haven, CT 06511, United States
| | - Ming-Qiang Zheng
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, United States
| | - Soheila Najafzadeh
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, United States
| | - Jean-Dominique Gallezot
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, United States
| | - Beata Planeta
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, United States
| | - Shannan Henry
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, United States
| | - Nabeel Nabulsi
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, United States
| | - Mohini Ranganathan
- Department of Psychiatry, Yale University School of Medicinev, New Haven, CT 06511, United States
| | - Patrick D Skosnik
- Department of Psychiatry, Yale University School of Medicinev, New Haven, CT 06511, United States
| | - Brian Pittman
- Department of Psychiatry, Yale University School of Medicinev, New Haven, CT 06511, United States
| | - Deepak Cyril D'Souza
- Department of Psychiatry, Yale University School of Medicinev, New Haven, CT 06511, United States
| | - Richard E Carson
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, United States
| | - Yiyun Huang
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, United States
| | - Marc N Potenza
- Department of Psychiatry, Yale University School of Medicinev, New Haven, CT 06511, United States; Child Study Center, Yale University School of Medicine, United States; Connecticut Mental Health Center, United States; Department of Neuroscience, Yale University, United States
| | - David Matuskey
- Department of Psychiatry, Yale University School of Medicinev, New Haven, CT 06511, United States; Department of Radiology and Biomedical Imaging, Yale University School of Medicine, United States; Department of Neurology, Yale University School of Medicine, United States
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3
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Ceccarini J, Koole M, Van Laere K. Cannabinoid receptor availability modulates the magnitude of dopamine release in vivo in the human reward system: A preliminary multitracer positron emission tomography study. Addict Biol 2022; 27:e13167. [PMID: 35470551 DOI: 10.1111/adb.13167] [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: 08/06/2021] [Revised: 02/21/2022] [Accepted: 03/08/2022] [Indexed: 12/01/2022]
Abstract
The established role of dopamine (DA) in the mediation of reward and positive reinforcement, reward processing is strongly influenced by the type 1 cannabinoid receptors (CB1 Rs). Although considerable preclinical evidence has demonstrated several functional CB1 R-DA interactions, the relation between human CB1 R availability, DA release capacity and drug-reinforcing effects has been never investigated so far. Here, we perform a multitracer [18 F]MK-9470 and [18 F]fallypride positron emission tomography (PET) study in 10 healthy male subjects using a placebo-controlled and single-blinded amphetamine (AMPH) (30 mg) administration paradigm to (1) investigate possible functional interactions between CB1 R expression levels and DA release capacity in a normo-DAergic state, relating in vivo AMPH-induced DA release to CB1 R availability, and (2) to test the hypothesis that the influence of striatal DAergic signalling on the positive reinforcing effects of AMPH may be regulated by prefrontal CB1 R levels. Compared with placebo, AMPH significantly reduced [18 F]fallypride binding potential (hence increase DA release; ΔBPND ranging from -6.1% to -9.6%) in both striatal (p < 0.005, corrected for multiple comparisons) and limbic extrastriatal regions (p ≤ 0.04, uncorrected). Subjects who reported a greater dopaminergic response in the putamen also showed higher CB1 R availability in the medial and dorsolateral prefrontal cortex (r = 0.72; p = 0.02), which are regions involved in salience attribution, motivation and decision making. On the other hand, the magnitude of DA release was greater in those subjects with lower CB1 R availability in the anterior cingulate cortex (ACC) (r = -0.66; p = 0.03). Also, the correlation between the DA release in the nucleus accumbens with the subjective AMPH effect liking was mediated through the CB1 R availability in the ACC (c' = -0.76; p = 0.01). Our small preliminary study reports for the first time that the human prefrontal CB1 R availability is a determinant of DA release within both the ventral and dorsal reward corticostriatal circuit, contributing to a number of studies supporting the existence of an interaction between CB1 R and DA receptors at the molecular and behavioural level. These preliminary findings warrant further investigation in pathological conditions characterized by hypo/hyper excitability to DA release such as addiction and schizophrenia.
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Affiliation(s)
- Jenny Ceccarini
- Nuclear Medicine and Molecular Imaging, Department of Imaging and Pathology KU Leuven Leuven Belgium
| | - Michel Koole
- Nuclear Medicine and Molecular Imaging, Department of Imaging and Pathology KU Leuven Leuven Belgium
| | - Koen Van Laere
- Nuclear Medicine and Molecular Imaging, Department of Imaging and Pathology KU Leuven Leuven Belgium
- Nuclear Medicine University Hospitals Leuven Leuven Belgium
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4
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Miederer I, Wiegand V, Bausbacher N, Leukel P, Maus S, Hoffmann MA, Lutz B, Schreckenberger M. Quantification of the Cannabinoid Type 1 Receptor Availability in the Mouse Brain. Front Neuroanat 2020; 14:593793. [PMID: 33328905 PMCID: PMC7714830 DOI: 10.3389/fnana.2020.593793] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 11/03/2020] [Indexed: 11/13/2022] Open
Abstract
Introduction: The endocannabinoid system is involved in several diseases such as addictive disorders, schizophrenia, post-traumatic stress disorder, and eating disorders. As often mice are used as the preferred animal model in translational research, in particular when using genetically modified mice, this study aimed to provide a systematic analysis of in vivo cannabinoid type 1 (CB1) receptor ligand-binding capacity using positron emission tomography (PET) using the ligand [18F]MK-9470. We then compared the PET results with literature data from immunohistochemistry (IHC) to review the consistency between ex vivo protein expression and in vivo ligand binding. Methods: Six male C57BL/6J (6–9 weeks) mice were examined with the CB1 receptor ligand [18F]MK-9470 and small animal PET. Different brain regions were evaluated using the parameter %ID/ml. The PET results of the [18F]MK-9470 accumulation in the mouse brain were compared with immunohistochemical literature data. Results: The ligand [18F]MK-9470 was taken up into the mouse brain within 5 min after injection and exhibited slow kinetics. It accumulated highly in most parts of the brain. PET and IHC classifications were consistent for most parts of the telencephalon, while brain regions of the diencephalon, mesencephalon, and rhombencephalon were rated higher with PET than IHC. Conclusions: This preclinical [18F]MK-9470 study demonstrated the radioligand’s applicability for imaging the region-specific CB1 receptor availability in the healthy adult mouse brain and thus offers the potential to study CB1 receptor availability in pathological conditions.
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Affiliation(s)
- Isabelle Miederer
- Department of Nuclear Medicine, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Viktoria Wiegand
- Department of Nuclear Medicine, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Nicole Bausbacher
- Department of Nuclear Medicine, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Petra Leukel
- Institute of Neuropathology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Stephan Maus
- Department of Nuclear Medicine, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Manuela A Hoffmann
- Department of Nuclear Medicine, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany.,Department of Occupational Health and Safety, Federal Ministry of Defense, Bonn, Germany
| | - Beat Lutz
- Institute of Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany.,Leibniz Institute for Resilience Research, Mainz, Germany
| | - Mathias Schreckenberger
- Department of Nuclear Medicine, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
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5
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Shafi A, Berry AJ, Sumnall H, Wood DM, Tracy DK. New psychoactive substances: a review and updates. Ther Adv Psychopharmacol 2020; 10:2045125320967197. [PMID: 33414905 PMCID: PMC7750892 DOI: 10.1177/2045125320967197] [Citation(s) in RCA: 111] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 09/26/2020] [Indexed: 12/19/2022] Open
Abstract
New psychoactive substances (NPS) are a heterogeneous group of substances. They are associated with a number of health and social harms on an individual and societal level. NPS toxicity and dependence syndromes are recognised in primary care, emergency departments, psychiatric inpatient and community care settings. One pragmatic classification system is to divide NPS into one of four groups: synthetic stimulants, synthetic cannabinoids, synthetic hallucinogens and synthetic depressants (which include synthetic opioids and benzodiazepines). We review these four classes of NPS, including their chemical structures, mechanism of action, modes of use, intended intoxicant effects, and their associated physical and mental health harms. The current challenges faced by laboratory testing for NPS are also explored, in the context of the diverse range of NPS currently available, rate of production and emergence of new substances, the different formulations, and methods of acquisition and distribution.
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Affiliation(s)
- Abu Shafi
- East London Foundation Trust, London, UK
| | - Alex J. Berry
- Division of Psychiatry, University College London, UK
| | | | - David M. Wood
- Clinical Toxicology, Guy’s and St Thomas’ NHS Foundation Trust, London, UK
- Clinical Toxicology, Faculty of Life Sciences and Medicine, King’s College London, London, UK
| | - Derek K. Tracy
- Consultant Psychiatrist, Oxleas NHS Foundation Trust, London, UK
- Department of Psychosis Studies, the Institute of Psychiatry, Psychology and Neuroscience, King’s College London, DeCrespigny Park, London, SE5 8AF, UK
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6
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D'Elia A, Schiavi S, Soluri A, Massari R, Soluri A, Trezza V. Role of Nuclear Imaging to Understand the Neural Substrates of Brain Disorders in Laboratory Animals: Current Status and Future Prospects. Front Behav Neurosci 2020; 14:596509. [PMID: 33362486 PMCID: PMC7759612 DOI: 10.3389/fnbeh.2020.596509] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 11/23/2020] [Indexed: 12/18/2022] Open
Abstract
Molecular imaging, which allows the real-time visualization, characterization and measurement of biological processes, is becoming increasingly used in neuroscience research. Scintigraphy techniques such as single photon emission computed tomography (SPECT) and positron emission tomography (PET) provide qualitative and quantitative measurement of brain activity in both physiological and pathological states. Laboratory animals, and rodents in particular, are essential in neuroscience research, providing plenty of models of brain disorders. The development of innovative high-resolution small animal imaging systems together with their radiotracers pave the way to the study of brain functioning and neurotransmitter release during behavioral tasks in rodents. The assessment of local changes in the release of neurotransmitters associated with the performance of a given behavioral task is a turning point for the development of new potential drugs for psychiatric and neurological disorders. This review addresses the role of SPECT and PET small animal imaging systems for a better understanding of brain functioning in health and disease states. Brain imaging in rodent models faces a series of challenges since it acts within the boundaries of current imaging in terms of sensitivity and spatial resolution. Several topics are discussed, including technical considerations regarding the strengths and weaknesses of both technologies. Moreover, the application of some of the radioligands developed for small animal nuclear imaging studies is discussed. Then, we examine the changes in metabolic and neurotransmitter activity in various brain areas during task-induced neural activation with special regard to the imaging of opioid, dopaminergic and cannabinoid receptors. Finally, we discuss the current status providing future perspectives on the most innovative imaging techniques in small laboratory animals. The challenges and solutions discussed here might be useful to better understand brain functioning allowing the translation of preclinical results into clinical applications.
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Affiliation(s)
- Annunziata D'Elia
- Institute of Biochemistry and Cell Biology, National Research Council of Italy (CNR), Rome, Italy
- Section of Biomedical Sciences and Technologies, Department of Science, University “Roma Tre”, Rome, Italy
| | - Sara Schiavi
- Section of Biomedical Sciences and Technologies, Department of Science, University “Roma Tre”, Rome, Italy
| | - Andrea Soluri
- Institute of Biochemistry and Cell Biology, National Research Council of Italy (CNR), Rome, Italy
| | - Roberto Massari
- Institute of Biochemistry and Cell Biology, National Research Council of Italy (CNR), Rome, Italy
| | - Alessandro Soluri
- Institute of Biochemistry and Cell Biology, National Research Council of Italy (CNR), Rome, Italy
| | - Viviana Trezza
- Section of Biomedical Sciences and Technologies, Department of Science, University “Roma Tre”, Rome, Italy
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Colom M, Vidal B, Zimmer L. Is There a Role for GPCR Agonist Radiotracers in PET Neuroimaging? Front Mol Neurosci 2019; 12:255. [PMID: 31680859 PMCID: PMC6813225 DOI: 10.3389/fnmol.2019.00255] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 10/02/2019] [Indexed: 12/30/2022] Open
Abstract
Positron emission tomography (PET) is a molecular imaging modality that enables in vivo exploration of metabolic processes and especially the pharmacology of neuroreceptors. G protein-coupled receptors (GPCRs) play an important role in numerous pathophysiologic disorders of the central nervous system. Thus, they are targets of choice in PET imaging to bring proof concept of change in density in pathological conditions or in pharmacological challenge. At present, most radiotracers are antagonist ligands. In vitro data suggest that properties differ between GPCR agonists and antagonists: antagonists bind to receptors with a single affinity, whereas agonists are characterized by two different affinities: high affinity for receptors that undergo functional coupling to G-proteins, and low affinity for those that are not coupled. In this context, agonist radiotracers may be useful tools to give functional images of GPCRs in the brain, with high sensitivity to neurotransmitter release. Here, we review all existing PET radiotracers used from animals to humans and their role for understanding the ligand-receptor paradigm of GPCR in comparison with corresponding antagonist radiotracers.
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Affiliation(s)
- Matthieu Colom
- Lyon Neuroscience Research Center, INSERM, CNRS, Université de Lyon, Lyon, France.,CERMEP, Hospices Civils de Lyon, Bron, France
| | - Benjamin Vidal
- Lyon Neuroscience Research Center, INSERM, CNRS, Université de Lyon, Lyon, France
| | - Luc Zimmer
- Lyon Neuroscience Research Center, INSERM, CNRS, Université de Lyon, Lyon, France.,CERMEP, Hospices Civils de Lyon, Bron, France.,Institut National des Sciences et Techniques Nucléaires, CEA Saclay, Gif-sur-Yvette, France
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8
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Ceccarini J, Casteels C, Ahmad R, Crabbé M, Van de Vliet L, Vanhaute H, Vandenbulcke M, Vandenberghe W, Van Laere K. Regional changes in the type 1 cannabinoid receptor are associated with cognitive dysfunction in Parkinson's disease. Eur J Nucl Med Mol Imaging 2019; 46:2348-2357. [PMID: 31342135 DOI: 10.1007/s00259-019-04445-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Accepted: 07/16/2019] [Indexed: 11/30/2022]
Abstract
PURPOSE The endocannabinoid system plays a regulatory role in a number of physiological functions, including motor control but also mood, emotion, and cognition. A number of preclinical studies in Parkinson's disease (PD) models demonstrated that modulating the type 1 cannabinoid receptor (CB1R) may improve motor symptoms and components of cognitive processing. However, the relation between CB1R, cognitive decline and behavioral symptoms has not been investigated in PD patients so far. The aim of this study was to examine whether CB1R availability is associated with measures of cognitive and behavioral function in PD patients. METHODS Thirty-eight PD patients and ten age- and gender-matched controls underwent a [18F]MK-9470 PET scan to assess CB1R availability, as well as volumetric MR imaging. Neuropsychological symptoms were evaluated using an extensive cognitive and behavioral battery covering the five cognitive domains, depression, anxiety, apathy, and psychiatric complications, and were correlated to CB1R availability using vowel-wise regression analysis (P < 0.05, corrected for familywise error). RESULTS PD patients with poorer performance in episodic memory, executive functioning, speed and mental flexibility (range P 0.003-0.03) showed lower CB1R availability in predominantly the midcingulate cortex and middle to superior frontal gyrus (Tpeak-level > 4.0). Also, PD patients with more severe visuospatial dysfunction showed decreased CB1R availability in the precuneus, midcingulate, supplementary motor cortex, inferior orbitofrontal gyrus and thalamus (Tpeak-level = 5.5). These correlations were not related to cortical gray matter atrophy. No relationship was found between CB1R availability and mood or behavioral symptom scores. CONCLUSIONS Decreased CB1R availability in the prefrontal and midcingulate cortex in PD patients is strongly correlated with disturbances in executive functioning, episodic memory, and visuospatial functioning. Further investigation of regional CB1R expression in groups of PD patients with mild cognitive impairment or dementia is warranted in order to further investigate the role of CB1R expression in different levels of cognitive impairment in PD.
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Affiliation(s)
- Jenny Ceccarini
- Nuclear Medicine and Molecular Imaging, University Hospitals Leuven, Herestraat 49, 3000, Leuven, Belgium. .,Department of Imaging and Pathology, KU Leuven, Leuven, Belgium.
| | - Cindy Casteels
- Nuclear Medicine and Molecular Imaging, University Hospitals Leuven, Herestraat 49, 3000, Leuven, Belgium.,Department of Imaging and Pathology, KU Leuven, Leuven, Belgium
| | - Rawaha Ahmad
- Nuclear Medicine and Molecular Imaging, University Hospitals Leuven, Herestraat 49, 3000, Leuven, Belgium.,Department of Imaging and Pathology, KU Leuven, Leuven, Belgium
| | - Melissa Crabbé
- Nuclear Medicine and Molecular Imaging, University Hospitals Leuven, Herestraat 49, 3000, Leuven, Belgium.,Department of Imaging and Pathology, KU Leuven, Leuven, Belgium
| | - Laura Van de Vliet
- Department of Old Age Psychiatry, University Psychiatric Centre, KU Leuven, Leuven, Belgium.,Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Heleen Vanhaute
- Nuclear Medicine and Molecular Imaging, University Hospitals Leuven, Herestraat 49, 3000, Leuven, Belgium.,Department of Imaging and Pathology, KU Leuven, Leuven, Belgium.,Department of Old Age Psychiatry, University Psychiatric Centre, KU Leuven, Leuven, Belgium
| | - Mathieu Vandenbulcke
- Department of Old Age Psychiatry, University Psychiatric Centre, KU Leuven, Leuven, Belgium.,Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Wim Vandenberghe
- Department of Neurosciences, KU Leuven, Leuven, Belgium.,Department of Neurology, University Hospitals Leuven, Leuven, Belgium
| | - Koen Van Laere
- Nuclear Medicine and Molecular Imaging, University Hospitals Leuven, Herestraat 49, 3000, Leuven, Belgium.,Department of Imaging and Pathology, KU Leuven, Leuven, Belgium
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10
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Jacobson MR, Watts JJ, Boileau I, Tong J, Mizrahi R. A systematic review of phytocannabinoid exposure on the endocannabinoid system: Implications for psychosis. Eur Neuropsychopharmacol 2019; 29:330-348. [PMID: 30635160 DOI: 10.1016/j.euroneuro.2018.12.014] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 07/17/2018] [Accepted: 12/20/2018] [Indexed: 12/18/2022]
Abstract
Cannabis, the most widely used illicit drug worldwide, produces psychoactive effects through its component cannabinoids, which act on the endocannabinoid system. Research on how cannabinoid exposure affects the endocannabinoid system is limited. Substantial evidence indicates cannabis use as a risk factor for psychosis, and the mechanism(s) by which this is occurring is/are currently unknown. Here, we conduct the first review of the effects of exogenous cannabinoids on the endocannabinoid system in humans with and without psychotic disorders. The most well established finding is the down-regulation of cannabinoid CB1 receptors (CB1R) after chronic and recent cannabis exposure, but it remains uncertain whether this effect is present in cannabis users with schizophrenia. We highlight where cannabis exposure affects the endocannabinoid system in a pattern that may mirror what is seen in psychosis, and how further research can push this field forward. In these times of changing cannabis legislation, research highlighting the biological effects of cannabinoids is greatly needed.
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Affiliation(s)
- Maya R Jacobson
- Research Imaging Centre, Centre for Addiction and Mental Health, 250 College St., Toronto, Ontario M5T 1R8, Canada; Department of Pharmacology and Toxicology, Faculty of Medicine, 1 King's College Circle, University of Toronto, Toronto, Ontario M5S 1A8, Canada.
| | - Jeremy J Watts
- Research Imaging Centre, Centre for Addiction and Mental Health, 250 College St., Toronto, Ontario M5T 1R8, Canada; Department of Pharmacology and Toxicology, Faculty of Medicine, 1 King's College Circle, University of Toronto, Toronto, Ontario M5S 1A8, Canada.
| | - Isabelle Boileau
- Research Imaging Centre, Centre for Addiction and Mental Health, 250 College St., Toronto, Ontario M5T 1R8, Canada; Centre for Addiction and Mental Health, Campbell Family Mental Health Research Institute, 250 College St., Toronto, Ontario M5T 1R8, Canada; Department of Psychiatry, University of Toronto, 250 College St., Toronto, Ontario M5T 1R8, Canada; Institute of Medical Science, Faculty of Medicine, 1 King's College Circle, University of Toronto, Ontario M5S 1A8, Canada.
| | - Junchao Tong
- Research Imaging Centre, Centre for Addiction and Mental Health, 250 College St., Toronto, Ontario M5T 1R8, Canada; Centre for Addiction and Mental Health, Campbell Family Mental Health Research Institute, 250 College St., Toronto, Ontario M5T 1R8, Canada; Department of Psychiatry, University of Toronto, 250 College St., Toronto, Ontario M5T 1R8, Canada.
| | - Romina Mizrahi
- Research Imaging Centre, Centre for Addiction and Mental Health, 250 College St., Toronto, Ontario M5T 1R8, Canada; Centre for Addiction and Mental Health, Campbell Family Mental Health Research Institute, 250 College St., Toronto, Ontario M5T 1R8, Canada; Department of Psychiatry, University of Toronto, 250 College St., Toronto, Ontario M5T 1R8, Canada; Department of Pharmacology and Toxicology, Faculty of Medicine, 1 King's College Circle, University of Toronto, Toronto, Ontario M5S 1A8, Canada; Institute of Medical Science, Faculty of Medicine, 1 King's College Circle, University of Toronto, Ontario M5S 1A8, Canada.
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11
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Laurikainen H, Tuominen L, Tikka M, Merisaari H, Armio RL, Sormunen E, Borgan F, Veronese M, Howes O, Haaparanta-Solin M, Solin O, Hietala J. Sex difference in brain CB1 receptor availability in man. Neuroimage 2018; 184:834-842. [PMID: 30296558 DOI: 10.1016/j.neuroimage.2018.10.013] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 09/20/2018] [Accepted: 10/04/2018] [Indexed: 12/17/2022] Open
Abstract
The endocannabinoid system (ECS) has a widespread neuromodulatory function in the central nervous system and is involved in important aspects of brain function including brain development, cortical rhythms, plasticity, reward, and stress sensitivity. Many of these effects are mediated via the cannabinoid CB1 receptor (CB1R) subtype. Animal studies convincingly show an interaction between the ECS and sex hormones, as well as a sex difference of higher brain CB1R in males. Human in vivo studies of sex difference have yielded discrepant findings. Gender differences in CB1R availability were investigated in vivo in 11 male and 11 female healthy volunteers using a specific CB1R tracer [18F]FMPEP-d2 and positron emission tomography (PET). Regional [18F]FMPEP-d2 distribution volume was used as a proxy for CB1R availability. In addition, we explored whether CB1R availability is linked to neuropsychological functioning. Relative to females, CB1R availability was on average 41% higher in males (p = 0.002) with a regionally specific effect larger in the posterior cingulate and retrosplenial cortices (p = 0.001). Inter-subject variability in CB1R availability was similar in both groups. Voxel-based analyses revealed an inverse association between CB1R availability and visuospatial working memory task performance in both groups (p < 0.001). A CB1R sex difference with a large effect size was observed and should be considered in the design of CB1R-related studies on neuropsychiatric disorders. The behavioural correlates and clinical significance of this difference remain to be further elucidated, but our studies suggest an association between CB1R availability and working memory.
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Affiliation(s)
- Heikki Laurikainen
- Turku PET Centre, Turku University Hospital, Finland; Department of Psychiatry, University of Turku and Turku University Hospital, Finland
| | - Lauri Tuominen
- Turku PET Centre, Turku University Hospital, Finland; Department of Psychiatry, University of Turku and Turku University Hospital, Finland; Martinos Center for Biomedical Imaging, Harvard Medical School, Boston, MA, USA
| | - Maria Tikka
- Department of Psychiatry, University of Turku and Turku University Hospital, Finland
| | | | - Reetta-Liina Armio
- Turku PET Centre, Turku University Hospital, Finland; Department of Psychiatry, University of Turku and Turku University Hospital, Finland
| | - Elina Sormunen
- Turku PET Centre, Turku University Hospital, Finland; Department of Psychiatry, University of Turku and Turku University Hospital, Finland
| | - Faith Borgan
- Psychosis Studies Department, Institute of Psychiatry, Psychology & Neuroscience, King's College London, UK
| | - Mattia Veronese
- Department of Neuroimaging, Institute of Psychiatry, Psychology & Neuroscience, King's College London, UK
| | - Oliver Howes
- Psychosis Studies Department, Institute of Psychiatry, Psychology & Neuroscience, King's College London, UK
| | | | - Olof Solin
- Turku PET Centre, Turku University Hospital, Finland
| | - Jarmo Hietala
- Turku PET Centre, Turku University Hospital, Finland; Department of Psychiatry, University of Turku and Turku University Hospital, Finland.
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Ceccarini J, Ahmad R, Van de Vliet L, Casteels C, Vandenbulcke M, Vandenberghe W, Van Laere K. Behavioral Symptoms in Premanifest Huntington Disease Correlate with Reduced Frontal CB1R Levels. J Nucl Med 2018; 60:115-121. [DOI: 10.2967/jnumed.118.210393] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Accepted: 05/24/2018] [Indexed: 11/16/2022] Open
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13
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Miederer I, Buchholz HG, Kronfeld A, Maus S, Weyer-Elberich V, Mildenberger P, Lutz B, Schreckenberger M. Pharmacokinetics of the cannabinoid receptor ligand [18
F]MK-9470 in the rat brain - Evaluation of models using microPET. Med Phys 2018; 45:725-734. [DOI: 10.1002/mp.12732] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 10/24/2017] [Accepted: 11/30/2017] [Indexed: 12/19/2022] Open
Affiliation(s)
- Isabelle Miederer
- Department of Nuclear Medicine; University Medical Center of the Johannes Gutenberg University Mainz; Langenbeckstraße 1 55131 Mainz Germany
| | - Hans-Georg Buchholz
- Department of Nuclear Medicine; University Medical Center of the Johannes Gutenberg University Mainz; Langenbeckstraße 1 55131 Mainz Germany
| | - Andrea Kronfeld
- Institute of Microscopic Anatomy and Neurobiology; University Medical Center of the Johannes Gutenberg University Mainz; Langenbeckstraße 1 55131 Mainz Germany
| | - Stephan Maus
- Department of Nuclear Medicine; University Medical Center of the Johannes Gutenberg University Mainz; Langenbeckstraße 1 55131 Mainz Germany
| | - Veronika Weyer-Elberich
- Institute of Medical Biostatistics, Epidemiology and Informatics; University Medical Center of the Johannes Gutenberg University Mainz; Obere Zahlbacher Straße 69 55131 Mainz Germany
| | - Philipp Mildenberger
- Institute of Medical Biostatistics, Epidemiology and Informatics; University Medical Center of the Johannes Gutenberg University Mainz; Obere Zahlbacher Straße 69 55131 Mainz Germany
| | - Beat Lutz
- Institute of Physiological Chemistry; University Medical Center of the Johannes Gutenberg University Mainz; Duesbergweg 6 55128 Mainz Germany
| | - Mathias Schreckenberger
- Department of Nuclear Medicine; University Medical Center of the Johannes Gutenberg University Mainz; Langenbeckstraße 1 55131 Mainz Germany
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14
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Cilia R. Molecular Imaging of the Cannabinoid System in Idiopathic Parkinson's Disease. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2018; 141:305-345. [DOI: 10.1016/bs.irn.2018.08.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/06/2022]
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15
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Schifani C, Hafizi S, Da Silva T, Watts JJ, Khan MS, Mizrahi R. Using molecular imaging to understand early schizophrenia-related psychosis neurochemistry: a review of human studies. Int Rev Psychiatry 2017; 29:555-566. [PMID: 29219634 PMCID: PMC8011813 DOI: 10.1080/09540261.2017.1396205] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Schizophrenia is a chronic psychiatric disorder generally preceded by a so-called prodromal phase, which is characterized by attenuated psychotic symptoms. Advances in clinical research have enabled prospective identification of those individuals who are at clinical high risk (CHR) for psychosis, with the power to predict psychosis onset within the near future. Changes in several brain neurochemical systems and molecular mechanisms are implicated in the pathophysiology of schizophrenia and the psychosis spectrum, including the dopaminergic, γ-aminobutyric acid (GABA)-ergic, glutamatergic, endocannabinoid, and immunologic (i.e. glial activation) system and other promising future directions such as synaptic density, which are possible to quantify in vivo using positron emission tomography (PET). This paper aims to review in vivo PET studies in the mentioned systems in the early course of psychosis (i.e. CHR and first-episode psychosis (FEP)). The results of reviewed studies are promising; however, the current understanding of the underlying pathology of psychosis is still limited. Importantly, promising efforts involve the development of novel PET radiotracers targeting systems with growing interest in schizophrenia, like the nociceptive system and synaptic density.
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Affiliation(s)
- Christin Schifani
- Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, ON, Canada
| | - Sina Hafizi
- Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, ON, Canada
| | - Tania Da Silva
- Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, ON, Canada
| | - Jeremy Joseph Watts
- Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, ON, Canada
| | - M. Saad Khan
- Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, ON, Canada
| | - Romina Mizrahi
- Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, ON, Canada
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada
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Ceccarini J, Weltens N, Ly HG, Tack J, Van Oudenhove L, Van Laere K. Association between cerebral cannabinoid 1 receptor availability and body mass index in patients with food intake disorders and healthy subjects: a [(18)F]MK-9470 PET study. Transl Psychiatry 2016; 6:e853. [PMID: 27404285 PMCID: PMC5545708 DOI: 10.1038/tp.2016.118] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Accepted: 04/25/2016] [Indexed: 01/15/2023] Open
Abstract
Although of great public health relevance, the mechanisms underlying disordered eating behavior and body weight regulation remain insufficiently understood. Compelling preclinical evidence corroborates a critical role of the endocannabinoid system (ECS) in the central regulation of appetite and food intake. However, in vivo human evidence on ECS functioning in brain circuits involved in food intake regulation as well as its relationship with body weight is lacking, both in health and disease. Here, we measured cannabinoid 1 receptor (CB1R) availability using positron emission tomography (PET) with [(18)F]MK-9470 in 54 patients with food intake disorders (FID) covering a wide body mass index (BMI) range (anorexia nervosa, bulimia nervosa, functional dyspepsia with weight loss and obesity; BMI range=12.5-40.6 kg/m(2)) and 26 age-, gender- and average BMI-matched healthy subjects (BMI range=18.5-26.6 kg/m(2)). The association between regional CB1R availability and BMI was assessed within predefined homeostatic and reward-related regions of interest using voxel-based linear regression analyses. CB1R availability was inversely associated with BMI in homeostatic brain regions such as the hypothalamus and brainstem areas in both patients with FID and healthy subjects. However, in FID patients, CB1R availability was also negatively correlated with BMI throughout the mesolimbic reward system (midbrain, striatum, insula, amygdala and orbitofrontal cortex), which constitutes the key circuit implicated in processing appetitive motivation and hedonic value of perceived food rewards. Our results indicate that the cerebral homeostatic CB1R system is inextricably linked to BMI, with additional involvement of reward areas under conditions of disordered body weight.
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Affiliation(s)
- J Ceccarini
- Division of Nuclear Medicine and Molecular Imaging, Department of Imaging and Pathology, University Hospitals Leuven, KU Leuven, Leuven, Belgium
| | - N Weltens
- Department of Clinical and Experimental Medicine, Translational Research Center for Gastrointestinal Disorders, KU Leuven, Leuven, Belgium
| | - H G Ly
- Department of Clinical and Experimental Medicine, Translational Research Center for Gastrointestinal Disorders, KU Leuven, Leuven, Belgium
| | - J Tack
- Department of Clinical and Experimental Medicine, Translational Research Center for Gastrointestinal Disorders, KU Leuven, Leuven, Belgium
- Department of Gastroenterology, University Hospitals Leuven, Leuven, Belgium
| | - L Van Oudenhove
- Department of Clinical and Experimental Medicine, Translational Research Center for Gastrointestinal Disorders, KU Leuven, Leuven, Belgium
- Liaison Psychiatry, University Psychiatric Center Campus Gasthuisberg, University Hospitals Leuven, Leuven, Belgium
| | - K Van Laere
- Division of Nuclear Medicine and Molecular Imaging, Department of Imaging and Pathology, University Hospitals Leuven, KU Leuven, Leuven, Belgium
- Leuven Institute for Neurobiology and Disease, KU Leuven, Leuven, Belgium
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Ly HG, Ceccarini J, Weltens N, Bormans G, Van Laere K, Tack J, Van Oudenhove L. Increased cerebral cannabinoid-1 receptor availability is a stable feature of functional dyspepsia: a [F]MK-9470 PET study. PSYCHOTHERAPY AND PSYCHOSOMATICS 2015; 84:149-58. [PMID: 25833408 DOI: 10.1159/000375454] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Accepted: 01/17/2015] [Indexed: 11/19/2022]
Abstract
BACKGROUND Functional dyspepsia (FD) is a prevalent functional gastrointestinal disorder (FGID) defined by chronic epigastric symptoms in the absence of organic abnormalities likely to explain them. Comorbidity with mood and anxiety disorders as well as with other FGIDs and functional somatic syndrome (FSS) is high. FD is characterized by abnormal regional cerebral activity in cognitive/affective pain modulatory circuits, but it is unknown which neurotransmitter systems are involved. The authors aimed to assess and compare in vivo cerebral cannabinoid-1 (CB1) receptor availability between FD patients and age-, gender- and BMI-matched healthy controls (HC). METHODS Twelve FD patients and 12 matched HC were investigated using positron emission tomography (PET) with the CB1 receptor radioligand [(18)F]MK-9470. Nine of the patients received a second PET scan after a naturalistic follow-up period of 36 ± 9.6 months (range: 25.2-50.4 months). RESULTS FD patients had significantly higher CB1 receptor availability in the cerebral regions involved in (visceral) nociception (brainstem, insula, anterior cingulate cortex) as well as in the homeostatic and hedonic regulation of food intake [hypothalamus, (ventral) striatum] (p < 0.05 corrected for multiple testing, region of interest analysis), which persisted after a follow-up period of 36 ± 9.6 months. CONCLUSIONS Although these findings need replication in larger samples, they suggest that the abnormal brain activity in several of these regions, previously demonstrated in FD, may be due to a sustained endocannabinoid system dysfunction, identifying it as a potential novel target for treatment and warranting further studies to elucidate whether it is also a feature of other FGIDs or FSSs.
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Affiliation(s)
- Huynh Giao Ly
- Translational Research Center for Gastrointestinal Disorders (TARGID), Department of Clinical and Experimental Medicine, Leuven, Belgium
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18
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Imaging the cannabinoid CB1 receptor in humans with [11C]OMAR: assessment of kinetic analysis methods, test-retest reproducibility, and gender differences. J Cereb Blood Flow Metab 2015; 35:1313-22. [PMID: 25833345 PMCID: PMC4528005 DOI: 10.1038/jcbfm.2015.46] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Revised: 02/05/2015] [Accepted: 02/08/2015] [Indexed: 12/13/2022]
Abstract
The Radiotracer [(11)C]OMAR was developed for positron emission tomography (PET) imaging of cannabinoid type-1 receptors (CB1R). The objectives of the present study were to evaluate kinetic analysis methods, determine test-retest reliability, and assess gender differences in receptor availability. Dynamic PET data were acquired in 10 human subjects, and analyzed with one-tissue (1T) and two-tissue (2T) compartment models and by the Logan and multilinear analysis (MA1) methods to estimate regional volume of distribution (VT). The 2T model inclusive of a vascular component (2TV) and MA1 were the preferred techniques. Test-retest reliability of VT was good (mean absolute deviation ~9%; intraclass correlation coefficient ~0.7). Tracer parent fraction in plasma was lower in women (P<0.0001). Cerebral uptake normalized by body weight and injected dose was higher in men by 17% (P<0.0001), but VT was significantly greater in women by 23% (P<0.0001). These findings show that [(11)C]OMAR binding can be reliably quantified by the 2T model or MA1 method and demonstrate the utility of this tracer for in vivo imaging of CB1R. In addition, results from the present study indicate that gender difference in receptor binding should be taken into consideration when [(11)C]OMAR is used to quantify CB1R availability in neuropsychiatric disorders.
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Hjorth S, Karlsson C, Jucaite A, Varnäs K, Wählby Hamrén U, Johnström P, Gulyás B, Donohue SR, Pike VW, Halldin C, Farde L. A PET study comparing receptor occupancy by five selective cannabinoid 1 receptor antagonists in non-human primates. Neuropharmacology 2015; 101:519-30. [PMID: 25791528 DOI: 10.1016/j.neuropharm.2015.03.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Revised: 02/05/2015] [Accepted: 03/07/2015] [Indexed: 01/14/2023]
Abstract
There is a medical need for safe and efficacious anti-obesity drugs with acceptable side effect profiles. To mitigate the challenge posed by translating target interaction across species and balancing beneficial vs. adverse effects, a positron emission tomography (PET) approach could help guide clinical dose optimization. Thus, as part of a compound differentiation effort, three novel selective CB1 receptor (CB1R) antagonists, developed by AstraZeneca (AZ) for the treatment of obesity, were compared with two clinically tested reference compounds, rimonabant and taranabant, with regard to receptor occupancy relative to dose and exposure. A total of 42 PET measurements were performed in 6 non-human primates using the novel CB1R antagonist radioligand [(11)C]SD5024. The AZ CB1R antagonists bound in a saturable manner to brain CB1R with in vivo affinities similar to that of rimonabant and taranabant, compounds with proven weight loss efficacy in clinical trials. Interestingly, it was found that exposures corresponding to those needed for optimal clinical efficacy of rimonabant and taranabant resulted in a CB1R occupancy typically around ∼20-30%, thus much lower than what would be expected for classical G-protein coupled receptor (GPCR) antagonists in other therapeutic contexts. These findings are also discussed in relation to emerging literature on the potential usefulness of 'neutral' vs. 'classical' CB1R (inverse agonist) antagonists. The study additionally highlighted the usefulness of the radioligand [(11)C]SD5024 as a specific tracer for CB1R in the primate brain, though an arterial input function would ideally be required in future studies to further assure accurate quantitative analysis of specific binding.
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Affiliation(s)
- Stephan Hjorth
- Biosciences, CVMD Innovative Medicines, AstraZeneca R&D, Mölndal, Sweden
| | - Cecilia Karlsson
- CVMD Translational Medicine Unit, Early Clinical Development, Innovative Medicines, AstraZeneca R&D, Mölndal, Sweden.
| | - Aurelija Jucaite
- AstraZeneca Translational Science Centre and Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Katarina Varnäs
- Centre for Psychiatric Research, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Ulrika Wählby Hamrén
- Quantitative Clinical Pharmacology, Early Clinical Development, Innovative Medicines, AstraZeneca R&D, Mölndal, Sweden
| | - Peter Johnström
- AstraZeneca Translational Science Centre and Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Balázs Gulyás
- Centre for Psychiatric Research, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Sean R Donohue
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA
| | - Victor W Pike
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA
| | - Christer Halldin
- Centre for Psychiatric Research, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Lars Farde
- AstraZeneca Translational Science Centre and Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
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Ceccarini J, Kuepper R, Kemels D, van Os J, Henquet C, Van Laere K. [18F]MK-9470 PET measurement of cannabinoid CB1 receptor availability in chronic cannabis users. Addict Biol 2015; 20:357-67. [PMID: 24373053 DOI: 10.1111/adb.12116] [Citation(s) in RCA: 96] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Δ(9) -Tetrahydrocannabinol, the main psychoactive component of cannabis, exerts its central effects through activation of the cerebral type 1 cannabinoid (CB1 ) receptor. Pre-clinical studies have provided evidence that chronic cannabis exposure is linked to decreased CB1 receptor expression and this is thought to be a component underlying drug tolerance and dependence. In this study, we make first use of the selective high-affinity positron emission tomography (PET) ligand [(18) F]MK-9470 to obtain in vivo measurements of cerebral CB1 receptor availability in 10 chronic cannabis users (age = 26.0 ± 4.1 years). Each patient underwent [(18) F]MK-9470 PET within the first week following the last cannabis consumption. A population of 10 age-matched healthy subjects (age = 23.0 ± 2.9 years) was used as control group. Parametric modified standardized uptake value images, reflecting CB1 receptor availability, were calculated. Statistical parametric mapping and volume-of-interest (VOI) analyses of CB1 receptor availability were performed. Compared with controls, cannabis users showed a global decrease in CB1 receptor availability (-11.7 percent). VOI-based analysis demonstrated that the CB1 receptor decrease was significant in the temporal lobe (-12.7 percent), anterior (-12.6 percent) and posterior cingulate cortex (-13.5 percent) and nucleus accumbens (-11.2 percent). Voxel-based analysis confirmed this decrease and regional pattern in CB1 receptor availability in cannabis users. These findings revealed that chronic cannabis use may alter specific regional CB1 receptor expression through neuroadaptive changes in CB1 receptor availability, opening the way for the examination of specific CB1 -cannabis addiction interactions which may predict future cannabis-related treatment outcome.
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Affiliation(s)
- Jenny Ceccarini
- Division of Nuclear Medicine; University Hospitals Leuven and Department of Imaging and Pathology; KU Leuven; Belgium
| | - Rebecca Kuepper
- Department of Psychiatry and Psychology; Maastricht University Medical Centre; South Limburg Mental Health Research and Teaching Network; EURON; The Netherlands
| | - Dieter Kemels
- Division of Nuclear Medicine; University Hospitals Leuven and Department of Imaging and Pathology; KU Leuven; Belgium
| | - Jim van Os
- Department of Psychiatry and Psychology; Maastricht University Medical Centre; South Limburg Mental Health Research and Teaching Network; EURON; The Netherlands
- Department of Psychosis Studies; Institute of Psychiatry; King's Health Partners; King's College London; UK
| | - Cécile Henquet
- Department of Psychiatry and Psychology; Maastricht University Medical Centre; South Limburg Mental Health Research and Teaching Network; EURON; The Netherlands
- PsyQ Heerlen; The Netherlands
| | - Koen Van Laere
- Division of Nuclear Medicine; University Hospitals Leuven and Department of Imaging and Pathology; KU Leuven; Belgium
- LIND, Leuven Institute for Neurobiology and Disease; KU Leuven; Belgium
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Abstract
Mounting evidence substantiates the central role of the endocannabinoid system (ECS) in the modulation of both homeostatic and hedonic elements of appetite and food intake. Conversely, feeding status and dietary patterns directly influence activity of the ECS. Following a general introduction on the functioning of the ECS, the present review specifically addresses its role in the modulation of hedonic eating. Humans possess strong motivational systems triggered by rewarding aspects of food. Food reward is comprised of two components: one appetitive (orienting towards food); the other consummatory (hedonic evaluation), also referred to as 'wanting' and 'liking', respectively. Endocannabinoid tone seems to influence both the motivation to feed and the hedonic value of foods, probably by modifying palatability. Human physiology underlying hedonic eating is still not fully understood. A better understanding of the role of the ECS in the rewarding value of specific foods or diets could offer new possibilities to optimise the balance between energy and nutrient intake for different target groups. These groups include the obese and overweight, and potentially individuals suffering from malnutrition. Examples for the latter group are patients with disease-related anorexia, as well as the growing population of frail elderly suffering from persistent loss of food enjoyment and appetite resulting in malnutrition and involuntary weight loss. It has become clear that the psychobiology of food hedonics is extremely complex and the clinical failure of CB1 inverse agonists including rimonabant (Accomplia®) has shown that 'quick wins' in this field are unlikely.
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Changes in cerebral CB1 receptor availability after acute and chronic alcohol abuse and monitored abstinence. J Neurosci 2014; 34:2822-31. [PMID: 24553924 DOI: 10.1523/jneurosci.0849-13.2014] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Involvement of the type 1 cannabinoid receptor (CB1R) in the effects of alcohol on the brain is supported by animal experiments, but how in vivo CB1R levels are altered in alcoholic patients is still unclear. To assess the short-time effects of a binge drinking episode on CB1R availability, 20 healthy social drinkers underwent [(18)F]MK-9470-positron emission tomography (PET) at baseline and after intravenous ethanol administration (ALC ACU). Moreover, 26 alcoholic patients underwent sequential CB1R PET after chronic heavy drinking (ALC CHR) and after 1 month of abstinence (ALC ABST). Seventeen healthy subjects served as controls. Compared with baseline, ALC ACU resulted in a global increase of CB1R availability (+15.8%). In contrast, a global decreased CB1R availability was found in ALC CHR patients (-16.1%) compared with controls, which remained unaltered after abstinence (-17.0%). Voxel-based analysis showed that ALC CHR patients had reduced CB1R availability, especially in the cerebellum and parieto-occipital cortex. After abstinence, reduced CB1R availability extended also to other areas such as the ventral striatum and mesotemporal lobe. In conclusion, whereas the acute alcohol effect is an increase in CB1R availability, chronic heavy drinking leads to reduced CB1R availability that is not reversible after 1 month of abstinence. Longer follow-up is required to differentiate whether this is a compensatory effect of repeated endocannabinoid overstimulation or an enduring trait-like feature. An enhanced CB1R signaling may offer a new therapeutic direction for treatment of the negative affective state produced by alcohol withdrawal and abstinence, which is critical for the maintenance of alcohol addiction.
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Ahmad R, Goffin K, Van den Stock J, De Winter FL, Cleeren E, Bormans G, Tournoy J, Persoons P, Van Laere K, Vandenbulcke M. In vivo type 1 cannabinoid receptor availability in Alzheimer's disease. Eur Neuropsychopharmacol 2014; 24:242-50. [PMID: 24189376 DOI: 10.1016/j.euroneuro.2013.10.002] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Revised: 10/04/2013] [Accepted: 10/09/2013] [Indexed: 11/16/2022]
Abstract
The endocannabinoid system (ECS) is an important modulatory and potentially neuroprotective homeostatic system in the brain. In Alzheimer's disease (AD), the role of type 1 cannabinoid receptor (CB₁R) is unclear, with contradictory findings in post-mortem studies showing upregulation, downregulation or unchanged CB₁R status. We have investigated CB₁R availability in vivo in patients with AD, in relation to amyloid deposition, cognitive functioning and apolipoprotein E (ApoE) genotype. Eleven AD patients and 7 healthy volunteers (HV) underwent combined [¹⁸F]MK-9470 PET and [¹¹C]PIB PET scans to assess CB₁R availability and amyloid deposition, respectively, and T1 volumetric MRI for partial volume correction. We found no difference in CB₁R availability between AD and HV, VOI-based fractional uptake values (FUR) were 0.043±0.01 for AD and 0.045±0.01 for controls (p=0.9). CB₁R availability did not correlate with neuropsychological test scores and was not modulated by ApoE genotype. As expected, global [¹¹C]PIB SUVR (standardized uptake value ratio) was increased in AD (SUVR 1.9±0.3) compared to HV (1.2±0.1) with p<0.001, but no correlation was found between amyloid β (Aβ) deposition and CB₁R availability. In conclusion, we found no in vivo evidence for a difference in CB₁R availability in AD compared to age-matched controls. Taken together with recently reported in vivo CB₁R changes in Parkinson's and Huntington's disease, these data suggest that the CB₁R is differentially involved in neurodegenerative disorders.
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Affiliation(s)
- Rawaha Ahmad
- Nuclear Medicine and Molecular Imaging, University Hospitals Leuven, Belgium; Department of Imaging & Pathology, KU Leuven, Belgium.
| | - Karolien Goffin
- Nuclear Medicine and Molecular Imaging, University Hospitals Leuven, Belgium; Department of Imaging & Pathology, KU Leuven, Belgium
| | - Jan Van den Stock
- Department of Old Age Psychiatry, University Hospitals Leuven, Belgium; Department of Neurosciences, KU Leuven, Belgium
| | - François-Laurent De Winter
- Department of Old Age Psychiatry, University Hospitals Leuven, Belgium; Department of Neurosciences, KU Leuven, Belgium
| | - Evy Cleeren
- Nuclear Medicine and Molecular Imaging, University Hospitals Leuven, Belgium; Department of Imaging & Pathology, KU Leuven, Belgium
| | - Guy Bormans
- Laboratory for Radiopharmacy, KU Leuven, Belgium
| | - Jos Tournoy
- Geriatric Medicine, University Hospitals Leuven, Belgium; Department of Clinical and Experimental Medicine, KU Leuven, Belgium
| | - Philippe Persoons
- Department of Old Age Psychiatry, University Hospitals Leuven, Belgium; Department of Neurosciences, KU Leuven, Belgium
| | - Koen Van Laere
- Nuclear Medicine and Molecular Imaging, University Hospitals Leuven, Belgium; Department of Imaging & Pathology, KU Leuven, Belgium
| | - Mathieu Vandenbulcke
- Department of Old Age Psychiatry, University Hospitals Leuven, Belgium; Department of Neurosciences, KU Leuven, Belgium
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Ceccarini J, De Hert M, Van Winkel R, Peuskens J, Bormans G, Kranaster L, Enning F, Koethe D, Leweke FM, Van Laere K. Increased ventral striatal CB1 receptor binding is related to negative symptoms in drug-free patients with schizophrenia. Neuroimage 2013; 79:304-12. [DOI: 10.1016/j.neuroimage.2013.04.052] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Revised: 03/26/2013] [Accepted: 04/15/2013] [Indexed: 11/16/2022] Open
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Tsujikawa T, Zoghbi SS, Hong J, Donohue SR, Jenko KJ, Gladding RL, Halldin C, Pike VW, Innis RB, Fujita M. In vitro and in vivo evaluation of (11)C-SD5024, a novel PET radioligand for human brain imaging of cannabinoid CB1 receptors. Neuroimage 2013; 84:733-41. [PMID: 24076222 DOI: 10.1016/j.neuroimage.2013.09.043] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Revised: 09/04/2013] [Accepted: 09/18/2013] [Indexed: 10/26/2022] Open
Abstract
We recently developed a novel cannabinoid subtype-1 (CB1) receptor radioligand (11)C-SD5024 for brain imaging. This study aimed to evaluate (11)C-SD5024 both in vitro and in vivo and compare it with the other CB1 receptor ligands previously used in humans, i.e., (11)C-MePPEP, (11)C-OMAR, (18)F-MK-9470, and (18)F-FMPEP-d2. In vitro experiments were performed to measure dissociation constant (Ki) in the human brain and to measure the lipophilicity of the five CB1 receptor ligands listed above. In vivo specific binding in monkeys was measured by comparing total distribution volume (VT) at baseline and after full receptor blockade. The kinetics of (11)C-SD5024 in humans were evaluated in seven healthy subjects with compartmental modeling. SD5024 showed Ki=0.47nM, which was at an intermediate level among the five CB1 receptor ligands. Lipophilicity (LogD7.4) was 3.79, which is appropriate for brain imaging. Monkey scans showed high proportion of specific binding: ~80% of VT. In humans, (11)C-SD5024 showed peak brain uptake of 1.5-3 standardized uptake value, which was slightly higher than that of (11)C-OMAR and (18)F-MK-9470. One-compartment model showed good fitting, consistent with the vast majority of brain uptake being specific binding found in the monkey. Regional VT values were consistent with known distribution of CB1 receptors. VT calculated from 80 and 120min of scan data was strongly correlated (R(2)=0.97), indicating that 80min provided adequate information for quantitation and that the influence of radiometabolites was low. Intersubject variability for VT of (11)C-SD5024 was 22%, which was low among the five radioligands and indicated precise measurement. In conclusion, (11)C-SD5024 has appropriate affinity and lipophilicity, high specific binding, moderate brain uptake, and provides good precision to measure the binding. The results suggest that (11)C-SD5024 is slightly better than or equivalent to (11)C-OMAR and that both are suitable for clinical studies, especially those that involve two scans in one day.
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Affiliation(s)
- Tetsuya Tsujikawa
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
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Casteels C, Gérard N, van Kuyck K, Pottel L, Nuttin B, Bormans G, Van Laere K. Small animal PET imaging of the type 1 cannabinoid receptor in a rodent model for anorexia nervosa. Eur J Nucl Med Mol Imaging 2013; 41:308-21. [PMID: 24006151 DOI: 10.1007/s00259-013-2522-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2013] [Accepted: 07/11/2013] [Indexed: 11/29/2022]
Abstract
PURPOSE Several lines of evidence strongly implicate a dysfunctional endocannabinoid system (ECS) in eating disorders. Using [(18)F]MK-9470 and small animal positron emission tomography (PET), we investigated for the first time cerebral changes in type 1 cannabinoid (CB1) receptor binding in vivo in the activity-based rat model of anorexia (ABA), in comparison to distinct motor- and food-related control conditions and in relation to gender and behavioural variables. METHODS In total, experiments were conducted on 80 Wistar rats (23 male and 57 female). Male rats were assigned to the cross-sectional conditions: ABA (n = 12) and CONTROL (n = 11), whereas female rats were divided between two settings: (1) a cross-sectional design using ABA (n = 13), CONTROL (n = 9), and two extra control conditions for each of the variables manipulated in ABA, i.e. DIET (n = 8) and WHEEL (n = 9), and (2) a longitudinal one using ABA (n = 10) and CONTROL (n = 8) studied at baseline, during the model and upon recovery. The ABA group was subjected to food restriction in the presence of a running wheel, the DIET group to food restriction without wheel, the WHEEL group to a normal diet with wheel and CONTROL animals had a normal diet and no running wheel. Parametric CB1 receptor images of each group were spatially normalized to Paxinos space and analysed voxel-wise. RESULTS In the ABA model, absolute [(18)F]MK-9470 binding was significantly increased in all cortical and subcortical brain areas as compared to control conditions (male +67 %; female >51%, all p cluster < 6.3×10(-6)) that normalized towards baseline values after weight gain. Additionally, relative [(18)F]MK-9470 binding was increased in the hippocampus, inferior colliculus and entorhinal cortex of female ABA (+4.6%; p cluster < 1.3×10(-6)), whereas no regional differences were observed in male subjects. Again, relative [(18)F]MK-9470 binding values normalized upon weight gain. CONCLUSION These data point to a widespread transient disturbance of the endocannabinoid transmission, specifically for CB1 receptors in the ABA model. Our data also suggest (1) gender effects on regional CB1 receptor binding in the hippocampus and (2) add further proof to the validity of the ABA model to mimic aspects of human disease.
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Affiliation(s)
- Cindy Casteels
- Division of Nuclear Medicine, University Hospital and KU Leuven, Herestraat 49 bus 7003, 3000, Leuven, Belgium,
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Emonds KM, Koole M, Casteels C, Van den Bergh L, Bormans GM, Claus F, De Wever L, Lerut E, Van Poppel H, Joniau S, Dumez H, Haustermans K, Mortelmans L, Goffin K, Van Laere K, Deroose CM, Mottaghy FM. 18F-MK-9470 PET imaging of the type 1 cannabinoid receptor in prostate carcinoma: a pilot study. EJNMMI Res 2013; 3:59. [PMID: 23915639 PMCID: PMC3750838 DOI: 10.1186/2191-219x-3-59] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Accepted: 07/19/2013] [Indexed: 11/30/2022] Open
Abstract
Background Preclinical and histological data show overexpression of the type 1 cannabinoid receptor (CB1R) in prostate carcinoma (PCa). In a prospective study, the feasibility of 18F-MK-9470 positron emission tomography (PET) imaging in patients with primary and metastatic PCa was evaluated. Methods Eight patients were included and underwent 18F-MK-9470 PET/CT imaging. For five patients with primary PCa, dynamic PET/CT imaging was performed over three acquisition intervals (0 to 30, 60 to 90 and 120 to 150 min post-injection). In malignant and benign prostate tissue regions, time activity curves of the mean standardized uptake value (SUVmean) were determined as well as the corresponding area under the curve to compare 18F-MK-9470 uptake over time. Muscle uptake of 18F-MK-9470 was used as reference for non-specific binding. Magnetic resonance imaging (MRI) was used as anatomical reference and for delineating intraprostatic tumours. Histological and immunohistochemical (IHC) examination was performed on the whole-mount histopathology sections of four patients who underwent radical prostatectomy to assess the MRI-based tumour versus benign tissue classification. For three patients with proven advanced metastatic disease, two static PET/CTs were performed 1 and 3 h post-injection. 18F-MK-9470 uptake was evaluated in bone lesions of metastatic PCa by comparing SUVmean values of metastases with these of the contralateral bone tissue. Results 18F-MK-9470 uptake was significantly higher in benign and malignant prostate tissue compared to muscle, but it did not differ between both prostate tissue compartments. IHC findings of corresponding prostatic histopathological sections indicated weak CB1R expression in locally confined PCa, which was not visualized with 18F-MK-9470 PET. Metastases in the axial skeleton could not be detected while some metastases in the appendicular skeleton showed higher 18F-MK-9470 uptake as compared to the uptake in contralateral normal bone. Conclusions 18F-MK-9470 PET could not detect local PCa or bone metastases in the axial skeleton but was able to visualize metastases in the appendicular skeleton. Based on these pilot observations, it seems unlikely that CB1R PET will play a significant role in the evaluation of PCa.
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Affiliation(s)
- Kimy M Emonds
- Department of Nuclear Medicine, University Hospitals Leuven, Leuven 3000, Belgium.
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Ahamed M, Verbruggen A, Bormans G. Synthetic strategies for radioligands forin vivoimaging of brain cannabinoid type-1 receptors. J Labelled Comp Radiopharm 2013; 56:207-14. [DOI: 10.1002/jlcr.3017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2012] [Revised: 11/28/2012] [Accepted: 11/30/2012] [Indexed: 02/03/2023]
Affiliation(s)
- Muneer Ahamed
- Laboratory for Radiopharmacy, IMIR KU Leuven, O&N2; Herestraat 49, Box 821; BE-3000; Leuven; Belgium
| | - Alfons Verbruggen
- Laboratory for Radiopharmacy, IMIR KU Leuven, O&N2; Herestraat 49, Box 821; BE-3000; Leuven; Belgium
| | - Guy Bormans
- Laboratory for Radiopharmacy, IMIR KU Leuven, O&N2; Herestraat 49, Box 821; BE-3000; Leuven; Belgium
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Vandeputte C, Casteels C, Struys T, Koole M, van Veghel D, Evens N, Gerits A, Dresselaers T, Lambrichts I, Himmelreich U, Bormans G, Van Laere K. Small-animal PET imaging of the type 1 and type 2 cannabinoid receptors in a photothrombotic stroke model. Eur J Nucl Med Mol Imaging 2012; 39:1796-806. [DOI: 10.1007/s00259-012-2209-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2012] [Accepted: 07/26/2012] [Indexed: 01/30/2023]
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Preclinical evaluation and quantification of [18F]MK-9470 as a radioligand for PET imaging of the type 1 cannabinoid receptor in rat brain. Eur J Nucl Med Mol Imaging 2012; 39:1467-77. [DOI: 10.1007/s00259-012-2163-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2012] [Accepted: 05/18/2012] [Indexed: 10/28/2022]
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Verdurand M, Nguyen V, Stark D, Zahra D, Gregoire MC, Greguric I, Zavitsanou K. Comparison of Cannabinoid CB(1) Receptor Binding in Adolescent and Adult Rats: A Positron Emission Tomography Study Using [F]MK-9470. INTERNATIONAL JOURNAL OF MOLECULAR IMAGING 2011; 2011:548123. [PMID: 22187642 PMCID: PMC3236487 DOI: 10.1155/2011/548123] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/16/2011] [Accepted: 09/17/2011] [Indexed: 12/14/2022]
Abstract
Despite the important role of cannabinoid CB(1) receptors (CB(1)R) in brain development, little is known about their status during adolescence, a critical period for both the development of psychosis and for initiation to substance abuse. In the present study, we assessed the ontogeny of CB(1)R in adolescent and adult rats in vivo using positron emission tomography with [(18)F]MK-9470. Analysis of covariance (ANCOVA) to control for body weight that would potentially influence [(18)F]MK-9470 values between the two groups revealed a main effect of age (F(1,109)=5.0, P = 0.02) on [(18)F]MK-9470 absolute binding (calculated as percentage of injected dose) with adult estimated marginal means being higher compared to adolescents amongst 11 brain regions. This finding was confirmed using in vitro autoradiography with [(3)H]CP55,940 (F(10,99)=140.1, P < 0.0001). This ontogenetic pattern, suggesting increase of CB(1)R during the transition from adolescence to adulthood, is the opposite of most other neuroreceptor systems undergoing pruning during this period.
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Affiliation(s)
- Mathieu Verdurand
- Schizophrenia Research Institute, Sydney, Australia
- ANSTO LifeSciences, ANSTO, PMB 1 Menai, Sydney, Australia
| | - Vu Nguyen
- ANSTO LifeSciences, ANSTO, PMB 1 Menai, Sydney, Australia
| | - Daniela Stark
- ANSTO LifeSciences, ANSTO, PMB 1 Menai, Sydney, Australia
| | - David Zahra
- ANSTO LifeSciences, ANSTO, PMB 1 Menai, Sydney, Australia
| | | | - Ivan Greguric
- ANSTO LifeSciences, ANSTO, PMB 1 Menai, Sydney, Australia
| | - Katerina Zavitsanou
- Schizophrenia Research Institute, Sydney, Australia
- School of Psychiatry, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia
- Schizophrenia Research Laboratory, Neuroscience Research Australia, Randwick, NSW, Australia
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Gérard N, Pieters G, Goffin K, Bormans G, Van Laere K. Brain type 1 cannabinoid receptor availability in patients with anorexia and bulimia nervosa. Biol Psychiatry 2011; 70:777-784. [PMID: 21718968 DOI: 10.1016/j.biopsych.2011.05.010] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2010] [Revised: 04/19/2011] [Accepted: 05/09/2011] [Indexed: 11/16/2022]
Abstract
BACKGROUND The endocannabinoid system is a possible target in the treatment of eating disorders. We used positron emission tomography to investigate the type 1 cannabinoid receptor (CB1R) in bulimic and anorectic patients. METHODS We investigated 16 female bulimia nervosa patients (BN) (age = 23.8 ± 7.1 years) and 14 female anorexia nervosa patients (AN) (age = 20.5 ± 3.6 years) using the selective CB1R ligand [(18)F]MK-9470. The control group consisted of 19 age-matched women (age = 25.2 ± 8.5 years). Statistical parametric mapping (p(family-wise error) < .05) and volume-of-interest analyses of CB1R availability were performed. RESULTS Global CB1R availability was significantly increased in cortical and subcortical brain areas in AN patients compared with healthy control subjects (+24.5%, p = .0003). Regionally, CB1R availability was increased in the insula in both AN and BN patients (p = .01 and p = .0004) and the inferior frontal and temporal cortex in AN patients only (p = .02). CONCLUSIONS Global CB1R upregulation in AN patients is a possible long-term compensatory mechanism to an underactive endocannabinoid system in anorectic conditions. There is a similarity in CB1R dysregulation both in AN and BN in the insular cortex, which is involved in the integration of interoceptive information, gustatory information, reward, and emotion processing.
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Affiliation(s)
- Nathalie Gérard
- Division of Nuclear Medicine, University Hospital and Katholieke Universiteit Leuven, Leuven, Belgium
| | - Guido Pieters
- University Psychiatric Centre, Katholieke Universiteit Leuven, Eating Disorder Clinic Kortenberg, Kortenberg, Belgium
| | - Karolien Goffin
- Division of Nuclear Medicine, University Hospital and Katholieke Universiteit Leuven, Leuven, Belgium
| | - Guy Bormans
- Laboratory for Radiopharmacy, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Koen Van Laere
- Division of Nuclear Medicine, University Hospital and Katholieke Universiteit Leuven, Leuven, Belgium.
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Van Laere K, Casteels C, Lunskens S, Goffin K, Grachev ID, Bormans G, Vandenberghe W. Regional changes in type 1 cannabinoid receptor availability in Parkinson's disease in vivo. Neurobiol Aging 2011; 33:620.e1-8. [PMID: 21459482 DOI: 10.1016/j.neurobiolaging.2011.02.009] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2010] [Revised: 01/12/2011] [Accepted: 02/13/2011] [Indexed: 10/18/2022]
Abstract
The type 1 cannabinoid receptor (CB1) is a crucial modulator of synaptic transmission in brain and has been proposed as a potential therapeutic target in Parkinson's disease (PD), especially for treatment of levodopa-induced dyskinesias (LID). Our aim was to measure CB1 levels in brains of PD patients in vivo and to investigate the relation between CB1 availability and LID. We studied 12 healthy controls and 29 PD patients (9 drug-naïve patients with early PD, 10 patients with advanced PD and LID, and 10 patients with advanced PD without LID). PD patients were examined using the Unified Parkinson's Disease Rating Scale (UPDRS) and the modified Abnormal Involuntary Movement Scale (mAIMS). All subjects underwent positron emission tomography (PET) with the CB1-selective radioligand [(18)F] MK-9470 and magnetic resonance imaging (MRI). PD patients showed an absolute decrease in CB1 availability in the substantia nigra. By contrast, CB1 availability was relatively increased in nigrostriatal, mesolimbic, and mesocortical dopaminergic projection areas. CB1 availability did not differ significantly between advanced PD patients with and without LID. Within the group of PD patients with LID, there was no significant correlation between CB1 availability and LID severity. These data demonstrate regional changes in CB1 availability in PD in vivo, but do not support a role for dysregulation of CB1 levels in the pathogenesis of LID.
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Affiliation(s)
- Koen Van Laere
- Department of Nuclear Medicine, University Hospitals Leuven, Leuven, Belgium.
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Casteels C, Vandeputte C, Rangarajan JR, Dresselaers T, Riess O, Bormans G, Maes F, Himmelreich U, Nguyen H, Van Laere K. Metabolic and type 1 cannabinoid receptor imaging of a transgenic rat model in the early phase of Huntington disease. Exp Neurol 2011; 229:440-9. [PMID: 21459091 DOI: 10.1016/j.expneurol.2011.03.014] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2011] [Revised: 03/11/2011] [Accepted: 03/21/2011] [Indexed: 01/11/2023]
Abstract
Several lines of evidence imply early alterations in metabolic and endocannabinoid neurotransmission in Huntington disease (HD). Using [(18)F]MK-9470 and small animal PET, we investigated for the first time cerebral changes in type 1 cannabinoid (CB1) receptor binding in vivo in pre-symptomatic and early symptomatic rats of HD (tgHD), in relation to glucose metabolism, morphology and behavioral testing for motor and cognitive function. Twenty-three Sprague-Dawley rats (14 tgHD and 9 wild-types) were investigated between the age of 2 and 11 months. Relative glucose metabolism and parametric CB1 receptor images were anatomically standardized to Paxinos space and analyzed voxel-wise. Volumetric microMRI imaging was performed to assess HD neuropathology. Within the first 10 months, bilateral volumes of caudate-putamen and lateral ventricles did not significantly differ between genotypes. Longitudinal- and genotype evolution showed that relative [(18)F]MK-9470 binding progressively decreased in the caudate-putamen and lateral globus pallidus of tgHD rats (-8.3%, p≤1.1×10(-5) at 5 months vs. -10.9%, p<1.5×10(-5) at 10 months). In addition, relative glucose metabolism increased in the bilateral sensorimotor cortex of 2-month-old tgHD rats (+8.1%, p≤1.5×10(-5)), where it was positively correlated to motor function at that time point. TgHD rats developed cognitive deficits at 6 and 11 months of age. Our findings point to early regional dysfunctions in endocannabinoid signalling, involving the lateral globus pallidus and caudate-putamen. In vivo CB1 receptor measurements using [(18)F]MK-9470 may thus be a useful early biomarker for HD. Our results also provide evidence of subtle motor and cognitive deficits at earlier stages than previously described.
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Affiliation(s)
- C Casteels
- Division of Nuclear Medicine, KU Leuven and University Hospital Leuven, Belgium.
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Goffin K, Van Paesschen W, Van Laere K. In vivo activation of endocannabinoid system in temporal lobe epilepsy with hippocampal sclerosis. Brain 2011; 134:1033-40. [DOI: 10.1093/brain/awq385] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Hirvonen J, Terry GE, Halldin C, Pike VW, Innis RB. Approaches to quantify radioligands that wash out slowly from target organs. Eur J Nucl Med Mol Imaging 2010; 37:917-9. [PMID: 20358196 DOI: 10.1007/s00259-010-1426-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Quantitative PET imaging of radioligands with slow kinetics in human brain. Eur J Nucl Med Mol Imaging 2010; 37:1613-5. [DOI: 10.1007/s00259-010-1518-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2010] [Accepted: 06/03/2010] [Indexed: 11/25/2022]
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Casteels C, Bormans G, Van Laere K. The effect of anaesthesia on [(18)F]MK-9470 binding to the type 1 cannabinoid receptor in the rat brain. Eur J Nucl Med Mol Imaging 2010; 37:1164-73. [PMID: 20182714 DOI: 10.1007/s00259-010-1383-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2009] [Accepted: 01/05/2010] [Indexed: 11/27/2022]
Abstract
PURPOSE Small animal PET can be applied to study molecular processes in animal models of a variety of human diseases. In order to keep the animals in a restricted position during imaging, anaesthesia is in many instances inevitable. Using small animal PET and ex vivo autoradiography, we examined the influence of pentobarbital and isoflurane anaesthesia on the rat brain uptake of [(18)F]MK-9470, a radioligand for the type 1 cannabinoid receptor. METHODS PET imaging was performed on adult Wistar rats under pentobarbital (n = 6) and isoflurane anaesthesia (n = 7), and under control conditions (free moving during tracer uptake, n = 8). Parametric PET images were generated, anatomically standardized and analysed by voxel-based Statistical Parametric Mapping and a predefined volume of interest approach. Immediately after in vivo PET, brains were processed for ex vivo autoradiography using manually placed regions of interest. An extra group (n = 6) was included ex vivo, in which animals were intravenously injected without the use of anaesthetics. RESULTS Using in vivo and ex vivo molecular imaging techniques, no significant changes in absolute [(18)F]MK-9470 uptake were present in the brain of pentobarbital and isoflurane rats as compared to control conditions. Relative [(18)F]MK-9470 uptake PET values obtained applying global scaling were, however, decreased in the cortex under both anaesthetics (pentobarbital: -13.3+/-1.4%; isoflurane -8.7 +/- 3.1%), while an increase was seen in the cerebellum by 13.5 +/- 4.0% and 13.9 +/- 4.1% under pentobarbital and isoflurane, respectively. Ex vivo results were in agreement with in vivo findings. CONCLUSION These findings suggest a similar, regionally specific interference of pentobarbital and isoflurane anaesthesia with in vivo CB1 receptor imaging using [(18)F]MK-9470.
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Affiliation(s)
- Cindy Casteels
- Division of Nuclear Medicine, KU Leuven and University Hospital Gasthuisberg, Herestraat 49 bus 7003, 3000, Leuven, Belgium.
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