2024
PET imaging of M4 muscarinic acetylcholine receptors in rhesus macaques using [11C]MK-6884: Quantification with kinetic modeling and receptor occupancy by CVL-231 (emraclidine), a novel positive allosteric modulator
Belov V, Guehl N, Duvvuri S, Iredale P, Moon S, Dhaynaut M, Chakilam S, MacDonagh A, Rice P, Yokell D, Renger J, Fakhri G, Normandin M. PET imaging of M4 muscarinic acetylcholine receptors in rhesus macaques using [11C]MK-6884: Quantification with kinetic modeling and receptor occupancy by CVL-231 (emraclidine), a novel positive allosteric modulator. Cerebrovascular And Brain Metabolism Reviews 2024, 44: 1329-1342. PMID: 38477292, PMCID: PMC11342722, DOI: 10.1177/0271678x241238820.Peer-Reviewed Original ResearchConceptsPositive allosteric modulatorsReceptor occupancyNon-human primatesBinding potentialPositron emission tomographyMuscarinic acetylcholine receptorsAllosteric modulatorsNon-human primate brainM4 muscarinic acetylcholine receptorStriatal hyperdopaminergiaAcetylcholine receptorsBrain regionsCaudate nucleusTotal volume of distributionDose-dependent blockReference regionVolume of distributionPositron emission tomography imagingEmission tomographyReceptor levelsFunction of dosePET scansClinical trialsBlood-basedRhesus macaquesHead-to-head comparison of [18F]-Flortaucipir, [18F]-MK-6240 and [18F]-PI-2620 postmortem binding across the spectrum of neurodegenerative diseases
Aguero C, Dhaynaut M, Amaral A, Moon S, Neelamegam R, Scapellato M, Carazo-Casas C, Kumar S, El Fakhri G, Johnson K, Frosch M, Normandin M, Gómez-Isla T. Head-to-head comparison of [18F]-Flortaucipir, [18F]-MK-6240 and [18F]-PI-2620 postmortem binding across the spectrum of neurodegenerative diseases. Acta Neuropathologica 2024, 147: 25. PMID: 38280071, PMCID: PMC10822013, DOI: 10.1007/s00401-023-02672-z.Peer-Reviewed Original ResearchConceptsNon-AD tauopathiesTau aggregationTau PET tracersDNA-binding proteinsBinds to neurofibrillary tanglesSecond-generation tau tracersTransactive response DNA-binding proteinSpectrum of neurodegenerative diseasesNeurofibrillary tanglesTau lesionsMelanin-containing cellsTDP-43Binding signalTauopathiesBinding targetsCerebral amyloid angiopathyOff-target bindingB-amyloidBinding patternsNeurodegenerative diseasesTau tracersTauBinding to areasBinding profilesBinding
2023
Tau Positron Emission Tomography and Neurocognitive Function Among Former Professional American-Style Football Players
Dhaynaut M, Grashow R, Normandin M, Wu O, Marengi D, Terry D, Sanchez J, Weisskopf M, Speizer F, Taylor H, Guehl N, Seshadri S, Beiser A, Daneshvar D, Johnson K, Iverson G, Zafonte R, Fakhri G, Baggish A. Tau Positron Emission Tomography and Neurocognitive Function Among Former Professional American-Style Football Players. Journal Of Neurotrauma 2023, 40: 1614-1624. PMID: 37282582, PMCID: PMC10458363, DOI: 10.1089/neu.2022.0454.Peer-Reviewed Original ResearchConceptsPositron emission tomographyDistribution volume ratioNeuropsychological testsNeurocognitive functionStandardized uptake value ratioControl participantsMeasures of neurocognitive functionStructural magnetic resonance imagingMeasures of memoryDepressive symptom severityMale control participantsEmission tomographyCerebellar gray matterNeuropsychological measuresTau positron emission tomographyExecutive functionSymptom severityBrain regionsEntorhinal cortexRepetitive head impactsP-tauReference regionFormer playersRepetitive head impact exposureMale controlsMeasurement of Cerebral Perfusion Indices from the Early Phase of [18F]MK6240 Dynamic Tau PET Imaging
Guehl N, Dhaynaut M, Hanseeuw B, Moon S, Lois C, Thibault E, Fu J, Price J, Johnson K, El Fakhri G, Normandin M. Measurement of Cerebral Perfusion Indices from the Early Phase of [18F]MK6240 Dynamic Tau PET Imaging. Journal Of Nuclear Medicine 2023, 64: 968-975. PMID: 36997330, PMCID: PMC10241011, DOI: 10.2967/jnumed.122.265072.Peer-Reviewed Original ResearchConceptsTime-activity curvesCerebral perfusionMetabolite-corrected arterial input functionBrain time-activity curvesEarly phaseRegional time-activity curvesIndices of cerebral perfusionDynamic [<sup>18</sup>FBlood-brain barrierPlasma to brain tissueStatistically significant differenceArterial blood samplesForty-nine subjectsCNArterial input functionPathophysiological mechanismsPerfusion indicatorsPET imagingBlood samplesSignificant differenceSurrogate indexNoninvasive estimationAnatomical informationCompound BForty-nine
2022
Radiochemical Synthesis and Evaluation of 3‑[11C]Methyl-4-aminopyridine in Rodents and Nonhuman Primates for Imaging Potassium Channels in the CNS
Sun Y, Guehl N, Zhou Y, Takahashi K, Belov V, Dhaynaut M, Moon S, Fakhri G, Normandin M, Brugarolas P. Radiochemical Synthesis and Evaluation of 3‑[11C]Methyl-4-aminopyridine in Rodents and Nonhuman Primates for Imaging Potassium Channels in the CNS. ACS Chemical Neuroscience 2022, 13: 3342-3351. PMID: 36417797, PMCID: PMC9732819, DOI: 10.1021/acschemneuro.2c00364.Peer-Reviewed Original ResearchConceptsRegional brain time-activity curvesBrain time-activity curvesOne-tissue compartment modelBlood-brain barrierConsistent with <i>inNonhuman primatesTime-activity curvesPositron emission tomographySpinal cord injuryDemyelinated neuronsNeurological symptomsPotassium channelsNeuronal conductionBrain uptakeEmission tomographyStille cross-couplingMultiple sclerosisCord injurySlow kineticsBrain permeabilityTraumatic brainMyelin sheathStronger binding affinityNeuronsBrainDesign, Synthesis, and Characterization of [18F]mG2P026 as a High-Contrast PET Imaging Ligand for Metabotropic Glutamate Receptor 2
Yuan G, Dhaynaut M, Guehl N, Afshar S, Huynh D, Moon S, Iyengar S, Jain M, Pickett J, Kang H, Ondrechen M, Fakhri G, Normandin M, Brownell A. Design, Synthesis, and Characterization of [18F]mG2P026 as a High-Contrast PET Imaging Ligand for Metabotropic Glutamate Receptor 2. Journal Of Medicinal Chemistry 2022, 65: 9939-9954. PMID: 35802702, PMCID: PMC9434700, DOI: 10.1021/acs.jmedchem.2c00593.Peer-Reviewed Original ResearchConceptsPositive allosteric modulatorsMetabotropic glutamate receptor 2Glutamate receptor 2Cu-mediated radiofluorinationPET imaging ligandsReceptor 2High molar activityExcellent radiochemical purityGloSensor assayPositron emission tomography radiotracersClasses of positive allosteric modulatorsNon-human primatesJNJ-46356479Radiochemical yieldBrain heterogeneityAllosteric modulatorsBrain uptakeMGluR2Molar activityLigandBrainBrain permeabilityImaging ligandsBinding kineticsMetabotropicImpact of 40 Hz Transcranial Alternating Current Stimulation on Cerebral Tau Burden in Patients with Alzheimer’s Disease: A Case Series1
Dhaynaut M, Sprugnoli G, Cappon D, Macone J, Sanchez J, Normandin M, Guehl N, Koch G, Paciorek R, Connor A, Press D, Johnson K, Pascual-Leone A, Fakhri G, Santarnecchi E. Impact of 40 Hz Transcranial Alternating Current Stimulation on Cerebral Tau Burden in Patients with Alzheimer’s Disease: A Case Series1. Journal Of Alzheimer's Disease 2022, 85: 1667-1676. PMID: 34958021, PMCID: PMC9023125, DOI: 10.3233/jad-215072.Peer-Reviewed Original ResearchConceptsMicroglia activationGamma spectral powerDecrease of microglia activationNo adverse eventsTranscranial alternating current stimulationSlow disease progressionPlacebo-controlled conditionsPreclinical dataCase seriesAdverse eventsGamma oscillationsElectrophysiological assessmentP-tauMouse modelDisease progressionMesial regionMild to moderate ADAnimal modelsPatientsPET imagingAlzheimer's diseaseSpectral powerAD mouse modelAD patientsProtein clearanceSynthesis and Characterization of 5‑(2-Fluoro-4‑[11C]methoxyphenyl)-2,2-dimethyl-3,4-dihydro‑2H‑pyrano[2,3‑b]pyridine-7-carboxamide as a PET Imaging Ligand for Metabotropic Glutamate Receptor 2
Yuan G, Dhaynaut M, Lan Y, Guehl N, Huynh D, Iyengar S, Afshar S, Jain M, Pickett J, Kang H, Wang H, Moon S, Ondrechen M, Wang C, Shoup T, Fakhri G, Normandin M, Brownell A. Synthesis and Characterization of 5‑(2-Fluoro-4‑[11C]methoxyphenyl)-2,2-dimethyl-3,4-dihydro‑2H‑pyrano[2,3‑b]pyridine-7-carboxamide as a PET Imaging Ligand for Metabotropic Glutamate Receptor 2. Journal Of Medicinal Chemistry 2022, 65: 2593-2609. PMID: 35089713, PMCID: PMC9434702, DOI: 10.1021/acs.jmedchem.1c02004.Peer-Reviewed Original ResearchConceptsNegative allosteric modulatorsMetabotropic glutamate receptor 2Positron emission tomographyGlutamate receptor 2MGluR2 functionNeuropsychiatric disordersDrug effectsBrain heterogeneityReceptor 2Allosteric modulatorsMGluR2Nonhuman primatesBrain imagingPositron emission tomography imagingPositron emission tomography imaging ligandsHigh molar activityEmission tomographyExcellent radiochemical purityImaging ligandsBlocking agentsPET imagingMolar activityTherapeutic targetMetabotropicDisorders
2021
Evaluation of Fluorinated Cromolyn Derivatives as Potential Therapeutics for Alzheimer’s Disease
Shoup T, Griciuc A, Normandin M, Quinti L, Walsh L, Dhaynaut M, Moon S, Guehl N, Brugarolas P, Elmaleh D, Fakhri G, Tanzi R. Evaluation of Fluorinated Cromolyn Derivatives as Potential Therapeutics for Alzheimer’s Disease. Journal Of Alzheimer's Disease 2021, 80: 775-786. PMID: 33579853, DOI: 10.3233/jad-201419.Peer-Reviewed Original ResearchConceptsMicroglial cellsCell toxicityPET imagingMultifactorial mechanism of actionBV2 microglial cellsDose-dependent mannerBV2 microglial cell lineMicroglial cell lineMechanism of actionF-18Multifactorial mechanismsPro-inflammatoryHigher perfusionLow perfusionRhesus macaquesCromolynCell linesIncreased uptakeTracer penetrationEnhanced uptakePotential therapeuticsPerfusionToxicityClearance assayClearanceSynthesis and Characterization of [18F]JNJ-46356479 as the First 18F-Labeled PET Imaging Ligand for Metabotropic Glutamate Receptor 2
Yuan G, Guehl N, Zheng B, Qu X, Moon S, Dhaynaut M, Shoup T, Afshar S, Kang H, Zhang Z, El Fakhri G, Normandin M, Brownell A. Synthesis and Characterization of [18F]JNJ-46356479 as the First 18F-Labeled PET Imaging Ligand for Metabotropic Glutamate Receptor 2. Molecular Imaging And Biology 2021, 23: 527-536. PMID: 33559035, PMCID: PMC8277681, DOI: 10.1007/s11307-021-01586-0.Peer-Reviewed Original ResearchConceptsNon-human primatesIn vivo PET imaging studiesNucleus accumbensGlutamate receptor 2PET imaging ligandsImaging ligandsParietal cortexBrain regionsPET imaging studiesPET radioligandIn vivo PET imaging experimentsVolume of distributionMGluR2C57BL/6 J micePET imaging experimentsPET studiesBrainSprague-Dawley ratsAlzheimer's diseaseBrain permeabilityPre-treatment studyImaging studiesDisordersRat studiesReversible kineticsRadiochemical Synthesis and Evaluation in Non-Human Primates of 3‑[11C]methoxy-4-aminopyridine: A Novel PET Tracer for Imaging Potassium Channels in the CNS
Guehl N, Neelamegam R, Zhou Y, Moon S, Dhaynaut M, Fakhri G, Normandin M, Brugarolas P. Radiochemical Synthesis and Evaluation in Non-Human Primates of 3‑[11C]methoxy-4-aminopyridine: A Novel PET Tracer for Imaging Potassium Channels in the CNS. ACS Chemical Neuroscience 2021, 12: 756-765. PMID: 33539063, PMCID: PMC8060895, DOI: 10.1021/acschemneuro.0c00791.Peer-Reviewed Original Research
2019
[18F]-AV-1451 binding profile in chronic traumatic encephalopathy: a postmortem case series
Marquié M, Agüero C, Amaral A, Villarejo-Galende A, Ramanan P, Chong M, Sáez-Calveras N, Bennett R, Verwer E, Kim S, Dhaynaut M, Alvarez V, Johnson K, McKee A, Frosch M, Gómez-Isla T. [18F]-AV-1451 binding profile in chronic traumatic encephalopathy: a postmortem case series. Acta Neuropathologica Communications 2019, 7: 164. PMID: 31661038, PMCID: PMC6816221, DOI: 10.1186/s40478-019-0808-1.Peer-Reviewed Original ResearchConceptsTau aggregationPositron emission tomographyTau lesionsPresence of tau aggregatesInferior parietal cortexSuperior temporal cortexPaired helical filamentsTau seeding activityHyperphosphorylated tau speciesDetection of tau aggregatesTraumatic encephalopathyPostmortem brain tissue samplesCorticobasal degenerationProgressive supranuclear palsyBinding profilesTau-containing lesionsRepetitive head traumaDifferential binding affinityFrontal cortexTemporal cortexParietal cortexTau conformationTau speciesBinding affinityOccipital cortexAutoradiography validation of novel tau PET tracer [F-18]-MK-6240 on human postmortem brain tissue
Aguero C, Dhaynaut M, Normandin M, Amaral A, Guehl N, Neelamegam R, Marquie M, Johnson K, El Fakhri G, Frosch M, Gomez-Isla T. Autoradiography validation of novel tau PET tracer [F-18]-MK-6240 on human postmortem brain tissue. Acta Neuropathologica Communications 2019, 7: 37. PMID: 30857558, PMCID: PMC6410510, DOI: 10.1186/s40478-019-0686-6.Peer-Reviewed Original ResearchConceptsIn vivo detection of neurofibrillary tanglesNeurofibrillary tanglesDetection of neurofibrillary tanglesAlzheimer's diseaseTDP-43Binds to neurofibrillary tanglesFrontotemporal lobar degeneration-tauOff-target bindingDNA-binding protein 43Binding patternsNon-Alzheimer tauopathiesHuman postmortem brain tissueTau aggregationPostmortem brain tissueBinding signalBinding targetsCerebral amyloid angiopathyIn vivo detectionB-amyloidNeurodegenerative diseasesHuman brain tissueTauTau positron emission tomographyBindingMK-6240