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Witek JA, Horikawa M, Henderson BD, Brooks AF, Scott PJH, Shao X. Improved Radiosynthesis and Automation of [ 11C]2-(2,6-Difluoro-4-((2-(N-methylphenylsulfonamido)ethyl)thio)phenoxy)acetamide ([ 11C]K2) for Positron Emission Tomography of the Glutamate α-Amino-3-hydroxy-5-methyl-4-isoxazole Propionic Acid (AMPA) Receptor. J Labelled Comp Radiopharm 2024; 67:324-329. [PMID: 38845124 PMCID: PMC11262959 DOI: 10.1002/jlcr.4113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2024] [Revised: 05/12/2024] [Accepted: 05/17/2024] [Indexed: 07/23/2024]
Abstract
A new automated radiosynthesis of [11C]2-(2,6-difluoro-4-((2-(N-methylphenylsulfonamido)ethyl)thio)phenoxy)acetamide ([11C]K2), a radiopharmaceutical for the glutamate α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptor, is reported. Although manual syntheses have been described, these are unsuitable for routine production of larger batches of [11C]K2 for (pre)clinical PET imaging applications. To meet demands for the imaging agent from our functional neuroimaging collaborators, herein, we report a current good manufacturing practice (cGMP)-compliant synthesis of [11C]K2 using a commercial synthesis module. The new synthesis is fully automated and has been validated for clinical use. The total synthesis time is 33 min from end of bombardment, and the production method provides 2.66 ± 0.3 GBq (71.9 ± 8.6 mCi) of [11C]K2 in 97.7 ± 0.5% radiochemical purity and 754.1 ± 231.5 TBq/mmol (20,382.7 ± 6256.1 Ci/mmol) molar activity (n = 3). Batches passed all requisite quality control testing confirming suitability for clinical use.
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Affiliation(s)
- Jason A. Witek
- Department of Radiology, University of Michigan Medical School, Ann Arbor, MI 48109, United States
| | - Mami Horikawa
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109, United States
| | - Bradford D. Henderson
- Department of Radiology, University of Michigan Medical School, Ann Arbor, MI 48109, United States
| | - Allen F. Brooks
- Department of Radiology, University of Michigan Medical School, Ann Arbor, MI 48109, United States
| | - Peter J. H. Scott
- Department of Radiology, University of Michigan Medical School, Ann Arbor, MI 48109, United States
| | - Xia Shao
- Department of Radiology, University of Michigan Medical School, Ann Arbor, MI 48109, United States
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Yonezawa K, Uchida H, Yatomi T, Ohtani Y, Nomoto-Takahashi K, Nakajima S, Mimura M, Tani H. Factors Associated with Antidepressant Effects of Ketamine: A Reanalysis of Double-Blind Randomized Placebo-Controlled Trial of Intravenous Ketamine for Treatment-Resistant Depression. PHARMACOPSYCHIATRY 2024; 57:35-40. [PMID: 37846462 DOI: 10.1055/a-2179-8884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2023]
Abstract
INTRODUCTION Predictors of treatment response to intravenous ketamine remain unclear in patients with treatment-resistant depression (TRD); therefore, this study aimed to clarify these predictors using the US National Institutes of Health database of clinical trials. METHODS Data from a placebo-controlled, double-blind, randomized controlled trial were used to assess the efficacy of intravenous ketamine in adult patients with TRD (NCT01920555). For the analysis, data were used from the participants who had received therapeutic doses of intravenous ketamine (i. e., 0.5 and 1.0 mg/kg). Logistic and multivariable regression analyses were conducted to explore the demographic and clinical factors associated with response to treatment or changes in the Hamilton Depression Rating Scale 6 items (HAM-D-6) total score. RESULTS This study included 31 patients with TRD (13 women; mean±standard deviation age, 48.4±10.9 years). Logistic regression analysis showed that the age of onset was positively correlated with treatment response after three days of ketamine administration (β=0.08, p=0.037); however, no association was observed between treatment response and age, sex, baseline HAM-D-6 total score, or dissociative score assessed with the Clinician-Administered Dissociative States Scale 40 min after ketamine infusion. Multiple regression analysis showed that no factors were correlated significantly with the percentage change in the HAM-D-6 total score three days after ketamine administration. DISCUSSION Later disease onset correlates with a better treatment response three days after ketamine infusion in patients with TRD. Glutamatergic signal transmission may be impaired in patients with an earlier onset of depression, resulting in decreased neuroplasticity, which diminishes ketamine response.
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Affiliation(s)
- Kengo Yonezawa
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo, Japan
| | - Hiroyuki Uchida
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo, Japan
| | - Taisuke Yatomi
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo, Japan
| | - Yohei Ohtani
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo, Japan
| | | | - Shinichiro Nakajima
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo, Japan
| | - Masaru Mimura
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo, Japan
| | - Hideaki Tani
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo, Japan
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Chen J, Ran W, Huang Y, Wei J, Rong J, Wei H, Li Y, Li G, Chen Z, Collier L, Elghazawy NH, Sippl W, Haider A, Liao K, Dong C, Li Y, Xu H, He W, Wang L, Liang SH. Evaluation of thiadiazine-based PET radioligands for imaging the AMPA receptor. Biomed Pharmacother 2023; 168:115842. [PMID: 37925936 DOI: 10.1016/j.biopha.2023.115842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 10/24/2023] [Accepted: 11/01/2023] [Indexed: 11/07/2023] Open
Abstract
As a subclass of ionotropic glutamate receptors (iGluRs), α-amino-3-hydroxyl-5-methyl-4-isoxazolepropionic acid (AMPA) receptors have been implicated in various neurological disorders and neurodegenerative diseases. To further our understanding of AMPA receptor-related disorders in the central nervous system (CNS), it is important to be able to image and quantify AMPA receptors in vivo. In this study, we identified a novel F-containing AMPA positive allosteric modulator (PAM) 6 as a potential lead compound. Molecular docking studies and CNS PET multi-parameter optimization (MPO) analysis were used to predict the absorption, distribution, metabolism, and excretion (ADME) characteristics of 6 as a PET probe. The resulting PET probe, [18F]6 (codename [18F]AMPA-2109), was successfully radiolabeled and demonstrated excellent blood-brain barrier (BBB) permeability and high brain uptake in rodents and non-human primates. However, [18F]6 did not show substantial specific binding in the rodent or non-human primate brain. Further medicinal chemistry efforts are necessary to improve specific binding, and our work may serve as a starting point for the design of novel 18F-labeled AMPA receptor-targeted PET radioligands aimed for clinical translation.
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Affiliation(s)
- Jiahui Chen
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI center, The First Affiliated Hospital of Jinan University, Guangzhou 510630, China; Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital & Department of Radiology, Harvard Medical School, Boston, MA 02114, USA
| | - Wenqing Ran
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI center, The First Affiliated Hospital of Jinan University, Guangzhou 510630, China
| | - Yiman Huang
- Medical Center of Stomatology, The First Affiliated Hospital of Jinan University, Jinan University School of Stomatology, Guangzhou 510630, China
| | - Junjie Wei
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI center, The First Affiliated Hospital of Jinan University, Guangzhou 510630, China; Key Laboratory of Basic and Translational Research on Radiopharmaceuticals, The First Affiliated Hospital of Jinan University, Guangzhou 510630, China
| | - Jian Rong
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital & Department of Radiology, Harvard Medical School, Boston, MA 02114, USA
| | - 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 510630, China
| | - Yinlong Li
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital & Department of Radiology, Harvard Medical School, Boston, MA 02114, USA
| | - Guocong Li
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI center, The First Affiliated Hospital of Jinan University, Guangzhou 510630, China; Key Laboratory of Basic and Translational Research on Radiopharmaceuticals, The First Affiliated Hospital of Jinan University, Guangzhou 510630, China
| | - Zhen Chen
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital & Department of Radiology, Harvard Medical School, Boston, MA 02114, USA
| | - Lee Collier
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital & Department of Radiology, Harvard Medical School, Boston, MA 02114, USA
| | - Nehal H Elghazawy
- Institute of Pharmacy, Department of Medicinal Chemistry, Martin-Luther-University Halle-Wittenberg, W.-Langenbeck-Str. 4, 06120 Halle, Germany
| | - Wolfgang Sippl
- Institute of Pharmacy, Department of Medicinal Chemistry, Martin-Luther-University Halle-Wittenberg, W.-Langenbeck-Str. 4, 06120 Halle, Germany
| | - Ahmed Haider
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital & Department of Radiology, Harvard Medical School, Boston, MA 02114, USA
| | - Kai Liao
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI center, The First Affiliated Hospital of Jinan University, Guangzhou 510630, China
| | - Chenchen Dong
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI center, The First Affiliated Hospital of Jinan University, Guangzhou 510630, China
| | - Ying Li
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI center, The First Affiliated Hospital of Jinan University, Guangzhou 510630, 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 510630, China; Key Laboratory of Basic and Translational Research on Radiopharmaceuticals, The First Affiliated Hospital of Jinan University, Guangzhou 510630, China
| | - Wenpeng He
- Medical Center of Stomatology, The First Affiliated Hospital of Jinan University, Jinan University School of Stomatology, Guangzhou 510630, China.
| | - 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 510630, China; Key Laboratory of Basic and Translational Research on Radiopharmaceuticals, The First Affiliated Hospital of Jinan University, Guangzhou 510630, China.
| | - Steven H Liang
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital & Department of Radiology, Harvard Medical School, Boston, MA 02114, USA.
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Eiro T, Miyazaki T, Hatano M, Nakajima W, Arisawa T, Takada Y, Kimura K, Sano A, Nakano K, Mihara T, Takayama Y, Ikegaya N, Iwasaki M, Hishimoto A, Noda Y, Miyazaki T, Uchida H, Tani H, Nagai N, Koizumi T, Nakajima S, Mimura M, Matsuda N, Kanai K, Takahashi K, Ito H, Hirano Y, Kimura Y, Matsumoto R, Ikeda A, Takahashi T. Dynamics of AMPA receptors regulate epileptogenesis in patients with epilepsy. Cell Rep Med 2023; 4:101020. [PMID: 37080205 DOI: 10.1016/j.xcrm.2023.101020] [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: 12/07/2022] [Revised: 02/08/2023] [Accepted: 03/22/2023] [Indexed: 04/22/2023]
Abstract
The excitatory glutamate α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptors (AMPARs) contribute to epileptogenesis. Thirty patients with epilepsy and 31 healthy controls are scanned using positron emission tomography with our recently developed radiotracer for AMPARs, [11C]K-2, which measures the density of cell-surface AMPARs. In patients with focal-onset seizures, an increase in AMPAR trafficking augments the amplitude of abnormal gamma activity detected by electroencephalography. In contrast, patients with generalized-onset seizures exhibit a decrease in AMPARs coupled with increased amplitude of abnormal gamma activity. Patients with epilepsy had reduced AMPAR levels compared with healthy controls, and AMPARs are reduced in larger areas of the cortex in patients with generalized-onset seizures compared with those with focal-onset seizures. Thus, epileptic brain function can be regulated by the enhanced trafficking of AMPAR due to Hebbian plasticity with increased simultaneous neuronal firing and compensational downregulation of cell-surface AMPARs by the synaptic scaling.
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Affiliation(s)
- Tsuyoshi Eiro
- Department of Physiology, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan; Department of Psychiatry, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan
| | - Tomoyuki Miyazaki
- Department of Physiology, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan
| | - Mai Hatano
- Department of Physiology, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan
| | - Waki Nakajima
- Department of Physiology, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan
| | - Tetsu Arisawa
- Department of Physiology, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan
| | - Yuuki Takada
- Department of Physiology, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan
| | - Kimito Kimura
- Department of Physiology, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan
| | - Akane Sano
- Department of Physiology, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan
| | - Kotaro Nakano
- Department of Physiology, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan
| | - Takahiro Mihara
- Department of Health Data Science, Yokohama City University Graduate School of Data Science, Yokohama 236-0004, Japan
| | - Yutaro Takayama
- Department of Neurosurgery, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan
| | - Naoki Ikegaya
- Department of Neurosurgery, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan
| | - Masaki Iwasaki
- Department of Neurosurgery, National Center Hospital, National Center of Neurology and Psychiatry, Kodaira 187-8551, Japan
| | - Akitoyo Hishimoto
- Department of Psychiatry, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan
| | - Yoshihiro Noda
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo 160-0016, Japan
| | - Takahiro Miyazaki
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo 160-0016, Japan
| | - Hiroyuki Uchida
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo 160-0016, Japan
| | - Hideaki Tani
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo 160-0016, Japan
| | - Nobuhiro Nagai
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo 160-0016, Japan
| | - Teruki Koizumi
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo 160-0016, Japan
| | - Shinichiro Nakajima
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo 160-0016, Japan
| | - Masaru Mimura
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo 160-0016, Japan
| | - Nozomu Matsuda
- Department of Neurology, Fukushima Medical University, Fukushima 960-1295, Japan
| | - Kazuaki Kanai
- Department of Neurology, Fukushima Medical University, Fukushima 960-1295, Japan
| | - Kazuhiro Takahashi
- Advanced Clinical Research Center, Fukushima Global Medical Science Center, Fukushima Medical University, Fukushima 960-1295, Japan
| | - Hiroshi Ito
- Advanced Clinical Research Center, Fukushima Global Medical Science Center, Fukushima Medical University, Fukushima 960-1295, Japan; Department of Radiology and Nuclear Medicine, Fukushima Medical University, Fukushima 960-1295, Japan
| | - Yoji Hirano
- Department of Neuropsychiatry, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan; Department of Psychiatry, Division of Clinical Neuroscience, Faculty of Medicine, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki 889-1692, Japan
| | - Yuichi Kimura
- Faculty of Informatics, Cyber Informatics Research Institute, Kindai University, Higashi-Osaka 577-8502, Japan
| | - Riki Matsumoto
- Division of Neurology, Kobe University Graduate School of Medicine, Kobe 650-0017, Japan
| | - Akio Ikeda
- Department of Epilepsy, Movement Disorders and Physiology, Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan
| | - Takuya Takahashi
- Department of Physiology, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan; The University of Tokyo, International Research Center for Neurointelligence, Tokyo 113-0033, Japan.
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Miyazaki T. [Quantification of AMPA receptor densities enables to disclose underlying mechanisms of neuropsychiatric disorders]. Nihon Yakurigaku Zasshi 2022; 157:196-199. [PMID: 35491118 DOI: 10.1254/fpj.21119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The excitatory glutamate AMPA receptor is the most important molecule for processing information in the brain. We have succeeded in developing the first-in-class PET drug ([11C] K-2) that visualizes AMPA receptors in the living human brain (Nature Medicine 2020). AMPA-PET imaging of patients with psychiatric disorders can disclose the molecular pathology underlying the diseases, contributing to the creation of novel disease animal models based on the phenotype of patients. Our research approach, basic and clinical fusion research, is expected to elucidate the biological basis for multiple neuropsychiatric disorders. AMPA-PET is attributed to the development of therapeutic methods targeting AMPA receptors, which have been delayed worldwide due to the inability of the technology to visualize AMPA receptors in human, leading to the foundation for the development of innovative diagnostic and therapeutic methods based on the molecular evidence of "seeing and treating AMPA receptors."
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Affiliation(s)
- Tomoyuki Miyazaki
- Department of Physiology, Graduate School of Medicine, Yokohama City University
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AMPA receptors in schizophrenia: A systematic review of postmortem studies on receptor subunit expression and binding. Schizophr Res 2022; 243:98-109. [PMID: 35247795 DOI: 10.1016/j.schres.2022.02.033] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 12/04/2021] [Accepted: 02/26/2022] [Indexed: 11/22/2022]
Abstract
BACKGROUND While altered expression of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) type receptor has been reported in postmortem studies of schizophrenia, these findings are inconsistent. Therefore, we aimed to systematically review postmortem studies that investigated AMPA receptor expressions in schizophrenia. METHODS A systematic literature search was conducted for postmortem studies that measured AMPA receptor subunit expressions or receptor bindings in schizophrenia compared to healthy individuals on February 3, 2021, using Medline and Embase. RESULTS A total of 39 relevant articles were identified from 1360 initial reports. The dorsolateral prefrontal cortex (DLPFC) was the most investigated region (15 studies), followed by the medial temporal lobe (8 studies). For the DLPFC, 4/15 studies (26.7%) showed increased AMPA receptor binding or subunit expression in patients with schizophrenia compared to that in controls, especially in GRIA1 and GRIA4, 2/15 studies (13.3%) reported a decrease, particularly in GRIA2, and 8/15 studies (56.7%) found no significant differences. A decreased expression or receptor binding was observed in 6/8 studies (75.0%) in the subregions of the hippocampus in patients with schizophrenia compared to that in controls, whereas the other two studies found no significant differences. CONCLUSION Published data have reported decreased subunit expression or receptor binding in the hippocampus in schizophrenia. These findings were inconsistent in other brain regions, which might be due to the heterogeneity of this population, various study design, physiological changes after death, and limited number of studies. Future in vivo studies are warranted to examine AMPA receptor expressions in human brains, together with their comprehensive clinical characterization.
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Synthesis of [18F] fluorine-labeled K-2 derivatives as radiotracers for AMPA receptors. Nucl Med Biol 2022; 110-111:47-58. [DOI: 10.1016/j.nucmedbio.2022.04.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 03/18/2022] [Accepted: 04/21/2022] [Indexed: 11/22/2022]
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Miyazaki T, Takayama Y, Iwasaki M, Hatano M, Nakajima W, Ikegaya N, Yamamoto T, Tsuchimoto S, Kato H, Takahashi T. OUP accepted manuscript. Brain Commun 2022; 4:fcac023. [PMID: 35415605 PMCID: PMC8994107 DOI: 10.1093/braincomms/fcac023] [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: 08/30/2021] [Revised: 11/11/2021] [Accepted: 02/03/2022] [Indexed: 11/13/2022] Open
Abstract
Presurgical identification of the epileptogenic zone is a critical determinant of seizure control following surgical resection in epilepsy. Excitatory glutamate α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor is a major component of neurotransmission. Although elevated α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor levels are observed in surgically resected brain areas of patients with epilepsy, it remains unclear whether increased α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor-mediated currents initiate epileptic discharges. We have recently developed the first PET tracer for α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor, [11C]K-2, to visualize and quantify the density of α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptors in living human brains. Here, we detected elevated [11C]K-2 uptake in the epileptogenic temporal lobe of patients with mesial temporal lobe epilepsy. Brain areas with high [11C]K-2 uptake are closely colocalized with the location of equivalent current dipoles estimated by magnetoencephalography or with seizure onset zones detected by intracranial electroencephalogram. These results suggest that epileptic discharges initiate from brain areas with increased α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptors, providing a biological basis for epileptic discharges and an additional non-invasive option to identify the epileptogenic zone in patients with mesial temporal lobe epilepsy.
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Affiliation(s)
- Tomoyuki Miyazaki
- Department of Physiology, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan
| | - Yutaro Takayama
- Department of Neurosurgery, National Center Hospital, National Center of Neurology and Psychiatry, Kodaira 187-8551, Japan
| | - Masaki Iwasaki
- Department of Neurosurgery, National Center Hospital, National Center of Neurology and Psychiatry, Kodaira 187-8551, Japan
| | - Mai Hatano
- Department of Physiology, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan
| | - Waki Nakajima
- Department of Physiology, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan
| | - Naoki Ikegaya
- Department of Neurosurgery, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan
| | - Tetsuya Yamamoto
- Department of Neurosurgery, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan
| | - Shohei Tsuchimoto
- Division of System Neuroscience, National Institute for Physiological Sciences, Okazaki 444-8585, Japan
| | - Hiroki Kato
- Department of Nuclear Medicine and Tracer Kinetics, Osaka University Graduate School of Medicine, Suita 565-0871, Japan
| | - Takuya Takahashi
- Department of Physiology, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan
- Correspondence to: Takuya Takahashi Department of Physiology, Yokohama City University Graduate School of Medicine Fukuura 3-9, Kanazawa-ku, Yokohama, 236-0004, Japan E-mail:
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