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 macaques
2023
Association of Pathologic and Volumetric Biomarker Changes With Cognitive Decline in Clinically Normal Adults
Hanseeuw B, Jacobs H, Schultz A, Buckley R, Farrell M, Guehl N, Becker J, Properzi M, Sanchez J, Quiroz Y, Vannini P, Sepulcre J, Yang H, Chhatwal J, Gatchel J, Marshall G, Amariglio R, Papp K, Rentz D, Normandin M, Price J, Healy B, El Fakhri G, Sperling R, Johnson K. Association of Pathologic and Volumetric Biomarker Changes With Cognitive Decline in Clinically Normal Adults. Neurology 2023, 101: e2533-e2544. PMID: 37968130, PMCID: PMC10791053, DOI: 10.1212/wnl.0000000000207962.Peer-Reviewed Original ResearchConceptsAssociated with cognitive declineOlder adultsNon-AD pathologyCognitive declineHippocampal volumeCognitive dataPreclinical Alzheimer Cognitive CompositeInferior temporal tauProspective cohort studyClinically normal older adultsHarvard Aging Brain StudyPittsburgh compound B PET scansOvert cognitive impairmentAnalyzed dataNormal older adultsAging Brain StudyClinically normal adultsLongitudinal associationsAlzheimer's diseaseCohort studyMemory impairmentCognitive compositeCognitive impairmentHippocampal atrophyCognition
2022
Human biodistribution and radiation dosimetry of the demyelination tracer [18F]3F4AP
Brugarolas P, Wilks M, Noel J, Kaiser J, Vesper D, Ramos-Torres K, Guehl N, Macdonald-Soccorso M, Sun Y, Rice P, Yokell D, Lim R, Normandin M, El Fakhri G. Human biodistribution and radiation dosimetry of the demyelination tracer [18F]3F4AP. European Journal Of Nuclear Medicine And Molecular Imaging 2022, 50: 344-351. PMID: 36197499, PMCID: PMC9816249, DOI: 10.1007/s00259-022-05980-w.Peer-Reviewed Original ResearchConceptsRadiation dosimetryTime-activity curvesAdverse eventsEffective doseMultiple bed positionsComprehensive metabolic panelNonhuman primatesHealthy human volunteersNo adverse eventsDynamic PET scansVoltage-gated potassiumAnimal models of neurological diseasesNonhuman primate studiesModels of neurological diseasesHuman biodistributionAverage effective doseMetabolic panelDosimetryOLINDA softwareHealthy volunteersUrinary bladderPET scansDemyelinating lesionsBed positionAnimal modelsImpact 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
2019
Evaluation 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 ResearchConceptsReference 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
2018
[18F]Fluorocholine and [18F]Fluoroacetate PET as Imaging Biomarkers to Assess Phosphatidylcholine and Mitochondrial Metabolism in Preclinical Models of TSC and LAM
Verwer E, Kavanagh T, Mischler W, Feng Y, Takahashi K, Wang S, Shoup T, Neelamegam R, Yang J, Guehl N, Ran C, Massefski W, Cui Y, El-Chemaly S, Sadow P, Oldham W, Kijewski M, Fakhri G, Normandin M, Priolo C. [18F]Fluorocholine and [18F]Fluoroacetate PET as Imaging Biomarkers to Assess Phosphatidylcholine and Mitochondrial Metabolism in Preclinical Models of TSC and LAM. Clinical Cancer Research 2018, 24: 5925-5938. PMID: 30054282, PMCID: PMC6816044, DOI: 10.1158/1078-0432.ccr-17-3693.Peer-Reviewed Original ResearchMeSH KeywordsAgedAnimalsBiomarkersCholineDisease Models, AnimalFemaleFluoroacetatesHeterograftsHumansImage Processing, Computer-AssistedImmunohistochemistryLipid MetabolismLymphangioleiomyomatosisMaleMiceMice, TransgenicMitochondriaOxygen ConsumptionPhosphatidylcholinesPositron-Emission TomographyRatsTuberous SclerosisConceptsTuberous sclerosis complexMetabolic imaging biomarkersPreclinical modelsImaging biomarkersTSC2-deficient cellsStandardized uptake valueTuberous sclerosis complex manifestationsModels of tuberous sclerosis complexAutosomal dominant disorderPotential clinical interestBenign tumorsOvariectomized miceUptake valueSubcutaneous tumorsPreclinical studiesPulmonary nodulesCystic destructionLymphangioleiomyomatosisDominant disorderProliferative lesionsInactivating mutationsTumorMetabolic reprogrammingNeurocognitive impairmentPET imaging