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 ResearchMeSH KeywordsAllosteric RegulationAnimalsAzabicyclo CompoundsBrainCarbon RadioisotopesCyclic S-OxidesFemaleKineticsMacaca mulattaMalePositron-Emission TomographyRadiopharmaceuticalsReceptor, Muscarinic M4ConceptsPositive 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 ResearchMeSH KeywordsAlzheimer DiseaseBrainCarbolinesDNA-Binding ProteinsHumansIsoquinolinesMelaninsMonoamine OxidaseNeurodegenerative DiseasesPositron-Emission TomographyPyridinesTau ProteinsTauopathiesConceptsNon-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 ResearchMeSH KeywordsAdultAmyloid beta-PeptidesBrainBrain ConcussionChronic Traumatic EncephalopathyFootballHumansMaleMiddle AgedPositron-Emission TomographyTau ProteinsConceptsPositron 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 ResearchMeSH KeywordsAlzheimer DiseaseAniline CompoundsBrainCerebrovascular CirculationCognitive DysfunctionHumansPositron-Emission TomographyConceptsTime-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
PET imaging studies to investigate functional expression of mGluR2 using [11C]mG2P001
Yuan G, Dhaynaut M, Guehl N, Neelamegam R, Moon S, Qu X, Poutiainen P, Afshar S, Fakhri G, Normandin M, Brownell A. PET imaging studies to investigate functional expression of mGluR2 using [11C]mG2P001. Cerebrovascular And Brain Metabolism Reviews 2022, 43: 296-308. PMID: 36172629, PMCID: PMC9903221, DOI: 10.1177/0271678x221130387.Peer-Reviewed Original ResearchMeSH KeywordsAnimalsCricetinaeCricetulusPositron-Emission TomographyRatsRats, Sprague-DawleyReceptors, Metabotropic GlutamateConceptsPositive allosteric modulatorsPositron emission tomographyNon-human primatesMGluR2 positive allosteric modulatorPositron emission tomography imagingPositive allosteric modulator of mGluR2Metabotropic glutamate receptor 2Positron emission tomography imaging studiesExpression of mGluR2Glutamate receptor 2MGluR2 functionPsychiatric disordersMGluR2 expressionTissue glutamate concentrationMGluR2Expressing mGluR2Allosteric modulatorsRat brainTransfected CHO cellsReceptor 2Glutamate concentrationEmission tomographyImaging studiesPharmacological effectsImaging ligandsDesign, 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 ResearchMeSH KeywordsAnimalsBrainLigandsPositron-Emission TomographyRadiopharmaceuticalsRatsRats, Sprague-DawleyReceptors, Metabotropic GlutamateConceptsPositive 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 kineticsMetabotropicPET imaging of mitochondrial function in acute doxorubicin-induced cardiotoxicity: a proof-of-principle study
Detmer F, Alpert N, Moon S, Dhaynaut M, Guerrero J, Guehl N, Xing F, Brugarolas P, Shoup T, Normandin M, Pelletier-Galarneau M, El Fakhri G, Petibon Y. PET imaging of mitochondrial function in acute doxorubicin-induced cardiotoxicity: a proof-of-principle study. Scientific Reports 2022, 12: 6122. PMID: 35414642, PMCID: PMC9005533, DOI: 10.1038/s41598-022-10004-6.Peer-Reviewed Original ResearchConceptsLeft anterior descending coronary arteryDoxorubicin-induced cardiotoxicityCardiac membrane potentialDoxorubicin infusionMembrane potentialAnimal modelsAcute doxorubicin-induced cardiotoxicityLeft anterior descending coronary artery territoryAcute cardiotoxic effectsAnterior descending coronary arteryControl saline infusionDescending coronary arteryDoxorubicin doseSaline infusionTest infusionCardiotoxic effectsMitochondrial membrane potentialInfusion catheterCoronary arteryInfusionMitochondrial functionDoxorubicinMyocardial areaPET imagingIntracoronary catheterImpact 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 ResearchMeSH KeywordsAgedAlzheimer DiseaseAmyloid beta-PeptidesAnimalsBrainEntorhinal CortexFemaleHumansMaleMiceMicrogliaPositron-Emission TomographyTau ProteinsTemporal LobeTranscranial Direct Current StimulationConceptsMicroglia 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
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
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 ResearchMeSH Keywords4-AminopyridineAnimalsBrainHaplorhiniPositron-Emission TomographyPotassium ChannelsRadiochemistry
2020
Evaluation of the potassium channel tracer [18F]3F4AP in rhesus macaques
Guehl N, Ramos-Torres K, Linnman C, Moon S, Dhaynaut M, Wilks M, Han P, Ma C, Neelamegam R, Zhou Y, Popko B, Correia J, Reich D, Fakhri G, Herscovitch P, Normandin M, Brugarolas P. Evaluation of the potassium channel tracer [18F]3F4AP in rhesus macaques. Cerebrovascular And Brain Metabolism Reviews 2020, 41: 1721-1733. PMID: 33090071, PMCID: PMC8221756, DOI: 10.1177/0271678x20963404.Peer-Reviewed Original ResearchMeSH KeywordsAminopyridinesAnimalsBrain InjuriesFluorine RadioisotopesMacaca mulattaMalePositron-Emission TomographyPotassium ChannelsRadioactive TracersRadiopharmaceuticalsConceptsFocal brain injuryMyelin repair therapyContributions of demyelinationDrivers of disabilityImaging demyelinationBrain injuryMeasurements of molecular changesTool's sensitivity to changesLower myelin contentDemyelinating lesionsNeuronal conductionImpaired conductionDemyelinationBrain penetrationGold standardRhesus macaquesInjured areaMultiple sclerosisMolecular changesMyelin sheathNeurological diseasesHigh metabolic stabilityMRI methodsMRIInjury
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 ResearchMeSH KeywordsAgedAged, 80 and overBrainCarbolinesChronic Traumatic EncephalopathyFemaleHumansMaleMiddle AgedPositron-Emission TomographyTau ProteinsTauopathiesConceptsTau 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 cortexEvaluation of pharmacokinetic modeling strategies for in-vivo quantification of tau with the radiotracer [18F]MK6240 in human subjects
Guehl N, Wooten D, Yokell D, Moon S, Dhaynaut M, Katz S, Moody K, Gharagouzloo C, Kas A, Johnson K, El Fakhri G, Normandin M. Evaluation of pharmacokinetic modeling strategies for in-vivo quantification of tau with the radiotracer [18F]MK6240 in human subjects. European Journal Of Nuclear Medicine And Molecular Imaging 2019, 46: 2099-2111. PMID: 31332496, PMCID: PMC6709592, DOI: 10.1007/s00259-019-04419-z.Peer-Reviewed Original ResearchMeSH KeywordsAgedAged, 80 and overAlzheimer DiseaseCognitive DysfunctionFemaleHumansIsoquinolinesMaleMiddle AgedModels, TheoreticalPositron-Emission TomographyRadiopharmaceuticalsTau ProteinsConceptsReference tissue methodDistribution volume ratioTissue methodIn vivo quantificationPharmacokinetic modeling strategiesArterial plasma input functionMultilinear reference tissue methodsTwo-tissue compartment modelBlood:plasma ratioTissue-to-plasmaPlasma input functionPlasma concentration time courseBlood-based methodMethodsThirty-five subjectsSUV ratioBlood-based analysesData setsArterial input functionPET scansControl subjectsMild cognitive impairmentPlasma ratioRadiometabolite analysisHealthy controlsConcentration time courseAutoradiography 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