Featured Publications
Imaging synaptic density in the living human brain
Finnema SJ, Nabulsi NB, Eid T, Detyniecki K, Lin SF, Chen MK, Dhaher R, Matuskey D, Baum E, Holden D, Spencer DD, Mercier J, Hannestad J, Huang Y, Carson RE. Imaging synaptic density in the living human brain. Science Translational Medicine 2016, 8: 348ra96. PMID: 27440727, DOI: 10.1126/scitranslmed.aaf6667.Peer-Reviewed Original ResearchConceptsSynaptic densityPositron emission tomographyPET imagingSynaptic vesicle glycoprotein 2ATemporal lobe epilepsyNumerous brain disordersCentral nervous systemNumber of synapsesJ PET imagingHuman brainHuman PET studiesPredominant neuronsSurgical resectionSynaptic lossLobe epilepsyPsychiatric disordersNervous systemBrain disordersPresynaptic boutonsAlzheimer's diseaseBrain tissueEmission tomographyNeuron contactsTherapeutic monitoringPET studiesFirst-in-Human Evaluation of 18F-SynVesT-1, a Radioligand for PET Imaging of Synaptic Vesicle Glycoprotein 2A
Naganawa M, Li S, Nabulsi N, Henry S, Zheng MQ, Pracitto R, Cai Z, Gao H, Kapinos M, Labaree D, Matuskey D, Huang Y, Carson RE. First-in-Human Evaluation of 18F-SynVesT-1, a Radioligand for PET Imaging of Synaptic Vesicle Glycoprotein 2A. Journal Of Nuclear Medicine 2020, 62: 561-567. PMID: 32859701, PMCID: PMC8049363, DOI: 10.2967/jnumed.120.249144.Peer-Reviewed Original ResearchConceptsC-UCBSynaptic densityRegional time-activity curvesTime-activity curvesDistribution volumeMetabolite-corrected arterial input functionPET imagingMultilinear analysis 1Synaptic vesicle glycoprotein 2AAntiepileptic drug levetiracetamTotal distribution volumeNondisplaceable distribution volumeCentrum semiovaleBlocking doseHealthy volunteersHuman studiesDrug levetiracetamLassen plotNeuropsychiatric disordersPET radioligandArterial input functionNonhuman primatesLevetiracetamReference regionRadioligandAssessing Synaptic Density in Alzheimer Disease With Synaptic Vesicle Glycoprotein 2A Positron Emission Tomographic Imaging
Chen MK, Mecca AP, Naganawa M, Finnema SJ, Toyonaga T, Lin SF, Najafzadeh S, Ropchan J, Lu Y, McDonald JW, Michalak HR, Nabulsi NB, Arnsten AFT, Huang Y, Carson RE, van Dyck CH. Assessing Synaptic Density in Alzheimer Disease With Synaptic Vesicle Glycoprotein 2A Positron Emission Tomographic Imaging. JAMA Neurology 2018, 75: 1215-1224. PMID: 30014145, PMCID: PMC6233853, DOI: 10.1001/jamaneurol.2018.1836.Peer-Reviewed Original ResearchConceptsPositron emission tomographic imagingSynaptic vesicle glycoprotein 2ASynaptic densityAlzheimer's diseaseEmission tomographic imagingHigh-resolution PET scanningPET scanningCognitive impairmentDisease-modifying therapiesDisease-modifying treatmentsNormal participantsCross-sectional studyPittsburgh compound BMajor structural correlateAmnestic mild cognitive impairmentMagnetic resonance imagingMild cognitive impairmentJ PET imagingRestoration of synapsesSpecific bindingNeurologic evaluationSynaptic lossDisease stagePostmortem studiesOutcome measuresLower synaptic density is associated with depression severity and network alterations
Holmes SE, Scheinost D, Finnema SJ, Naganawa M, Davis MT, DellaGioia N, Nabulsi N, Matuskey D, Angarita GA, Pietrzak RH, Duman RS, Sanacora G, Krystal JH, Carson RE, Esterlis I. Lower synaptic density is associated with depression severity and network alterations. Nature Communications 2019, 10: 1529. PMID: 30948709, PMCID: PMC6449365, DOI: 10.1038/s41467-019-09562-7.Peer-Reviewed Original ResearchConceptsMajor depressive disorderPost-traumatic stress disorderLower synaptic densitySynaptic densityPositron emission tomographyFunctional connectivityNetwork alterationsSynaptic vesicle glycoprotein 2ASymptoms of depressionSynaptic lossDepressive disorderHealthy controlsNerve terminalsDepressive symptomsDepression severityUnmedicated individualsSynaptic connectionsEmission tomographyStress disorderVivo evidenceSymptomsDepressionSeverityDisordersAlterations
2024
Synaptic loss and its association with symptom severity in Parkinson’s disease
Holmes S, Honhar P, Tinaz S, Naganawa M, Hilmer A, Gallezot J, Dias M, Yang Y, Toyonaga T, Esterlis I, Mecca A, Van Dyck C, Henry S, Ropchan J, Nabulsi N, Louis E, Comley R, Finnema S, Carson R, Matuskey D. Synaptic loss and its association with symptom severity in Parkinson’s disease. Npj Parkinson's Disease 2024, 10: 42. PMID: 38402233, PMCID: PMC10894197, DOI: 10.1038/s41531-024-00655-9.Peer-Reviewed Original ResearchSynaptic density lossPositron emission tomographyBinds to synaptic vesicle glycoprotein 2AAssociated with symptom severityParkinson's diseaseHigh-resolution positron emission tomographySynaptic vesicle glycoprotein 2ADuration of illnessPositron emission tomography scanBrain perfusionIllness durationSymptom severitySeverity of symptomsHC groupSubstantia nigraSynaptic densityLiving brainPD individualsClinical insightsDensity lossPD patientsEmission tomographyBrainSynaptic lossSynapse lossFirst-in-Human Study of 18F-SynVesT-2: An SV2A PET Imaging Probe with Fast Brain Kinetics and High Specific Binding
Drake L, Wu Y, Naganawa M, Asch R, Zheng C, Najafzadeh S, Pracitto R, Lindemann M, Li S, Ropchan J, Labaree D, Emery P, Dias M, Henry S, Nabulsi N, Matuskey D, Hillmer A, Gallezot J, Carson R, Cai Z, Huang Y. First-in-Human Study of 18F-SynVesT-2: An SV2A PET Imaging Probe with Fast Brain Kinetics and High Specific Binding. Journal Of Nuclear Medicine 2024, 65: jnumed.123.266470. PMID: 38360052, PMCID: PMC10924160, DOI: 10.2967/jnumed.123.266470.Peer-Reviewed Original ResearchFirst-in-human studyPlasma free fractionTime-activity curvesCentrum semiovaleNonhuman primate's resultsFirst-in-humanFree fractionNondisplaceable binding potentialRegional time-activity curvesLow nonspecific uptakeRegional distribution volumesHigh-resolution research tomograph scannerTest-retest reproducibilityCerebral blood flowSynaptic vesicle glycoprotein 2AHealthy volunteersArterial input functionNonspecific uptakePET imaging probeDistribution volumeSynapse densityIndividual MR imagesHighest specific bindingMR imagingPET imagingA pilot study to evaluate the effect of CT1812 treatment on synaptic density and other biomarkers in Alzheimer’s disease
van Dyck C, Mecca A, O’Dell R, Bartlett H, Diepenbrock N, Huang Y, Hamby M, Grundman M, Catalano S, Caggiano A, Carson R. A pilot study to evaluate the effect of CT1812 treatment on synaptic density and other biomarkers in Alzheimer’s disease. Alzheimer's Research & Therapy 2024, 16: 20. PMID: 38273408, PMCID: PMC10809445, DOI: 10.1186/s13195-024-01382-2.Peer-Reviewed Original ResearchConceptsMild to moderate dementiaPositron emission tomographyAlzheimer's diseaseVolumetric MRIModerate dementiaClinical rating scalesSynaptic vesicle glycoprotein 2ACerebrospinal fluidMouse model of ADPharmacodynamic effectsPlacebo-controlled phase 1 clinical trialBiomarkers of AD pathologyClinical trialsCognitive measuresNominally significant differencesPhase 1 clinical trialModel of ADHippocampal cortexPhase 1/2 studyRating ScaleParallel-group trialSynaptic densityTrial registrationThe clinical trialPlacebo-controlledSigma-2 receptor ligands
2023
The regional pattern of age-related synaptic loss in the human brain differs from gray matter volume loss: in vivo PET measurement with [11C]UCB-J
Toyonaga T, Khattar N, Wu Y, Lu Y, Naganawa M, Gallezot J, Matuskey D, Mecca A, Pittman B, Dias M, Nabulsi N, Finnema S, Chen M, Arnsten A, Radhakrishnan R, Skosnik P, D’Souza D, Esterlis I, Huang Y, van Dyck C, Carson R. The regional pattern of age-related synaptic loss in the human brain differs from gray matter volume loss: in vivo PET measurement with [11C]UCB-J. European Journal Of Nuclear Medicine And Molecular Imaging 2023, 51: 1012-1022. PMID: 37955791, DOI: 10.1007/s00259-023-06487-8.Peer-Reviewed Original ResearchSynaptic densityAge-related decreaseMagnetic resonance imagingBlood flowAge-related synaptic lossGray matter volume lossSynaptic density lossPositron emission tomography (PET) ligandSynaptic vesicle glycoprotein 2AVivo PET measurementsMedial occipital cortexGray matter volumeAge-related neurodegenerationGray matter regionsCognitive normal subjectsAge-related changesSynaptic lossNerve terminalsWide age rangeOccipital cortexTomography ligandNormal subjectsGM volumeAge-related functional lossesMatter volumeSynaptic PET Imaging in Neurodegeneration
Chen M, Matuskey D, Finnema S, Carson R. Synaptic PET Imaging in Neurodegeneration. 2023, 157-167. DOI: 10.1007/978-3-031-35098-6_10.ChaptersAlzheimer's diseaseSynaptic densityProgressive supranuclear palsySynaptic vesicle glycoprotein 2ALarge patient cohortPositron emission tomography (PET) biomarkersInitial PET studiesMultiple neurodegenerative diseasesSupranuclear palsyCorticobasal degenerationLewy bodiesPatient cohortSynapse densityTomography biomarkersClinical valueParkinson's diseaseNeurological diseasesBrain regionsFrontotemporal dementiaPET studiesDiseaseNeurodegenerative diseasesHuntington's diseaseMultiple centersSynaptic vesicle membraneAssessment of Gray Matter Microstructure and Synaptic Density in Alzheimer's Disease: A Multimodal Imaging Study With DTI and SV2A PET
Silva-Rudberg J, Salardini E, O'Dell R, Chen M, Ra J, Georgelos J, Morehouse M, Melino K, Varma P, Toyonaga T, Nabulsi N, Huang Y, Carson R, van Dyck C, Mecca A. Assessment of Gray Matter Microstructure and Synaptic Density in Alzheimer's Disease: A Multimodal Imaging Study With DTI and SV2A PET. American Journal Of Geriatric Psychiatry 2023, 32: 17-28. PMID: 37673749, PMCID: PMC10840732, DOI: 10.1016/j.jagp.2023.08.002.Peer-Reviewed Original ResearchSynaptic densityAlzheimer's diseaseMean diffusivitySynaptic lossGray matter microstructureGray matter mean diffusivityDisease pathologyHippocampal synaptic densityMajor pathological correlateSetting of ADAD-related neuropathologySynaptic vesicle glycoprotein 2AHippocampal mean diffusivityAlzheimer's disease pathologyAmyloid-positive participantsMatter mean diffusivityPositron emission tomography (PET) imagingEmission Tomography ImagingGray matter structuresPathological correlatesPositive participantsInverse associationAD groupCognitive impairmentDiseaseDecreased synaptic vesicle glycoprotein 2A binding in a rodent model of familial Alzheimer's disease detected by [18F]SDM-16
Zheng C, Toyonaga T, Chen B, Nicholson L, Mennie W, Liu M, Spurrier J, Deluca K, Strittmatter S, Carson R, Huang Y, Cai Z. Decreased synaptic vesicle glycoprotein 2A binding in a rodent model of familial Alzheimer's disease detected by [18F]SDM-16. Frontiers In Neurology 2023, 14: 1045644. PMID: 36846134, PMCID: PMC9945093, DOI: 10.3389/fneur.2023.1045644.Peer-Reviewed Original ResearchStandardized uptake value ratioDistribution volume ratioAlzheimer's diseaseSimplified reference tissue modelSynapse lossMouse modelAPP/PS1 miceAge-matched wild-type miceAPPswe/PS1dE9 mouse modelAPP/PS1 AD mouse modelSlow brain kineticsAD mouse modelSynaptic vesicle glycoprotein 2APseudo-reference regionWild-type miceUptake value ratioMonths of ageDifferent brain regionsDifferent imaging windowsFamilial Alzheimer's diseasePET imaging studiesReference tissue modelPS1 miceBrain stemBrain kinetics
2022
Drug characteristics derived from kinetic modeling: combined 11C-UCB-J human PET imaging with levetiracetam and brivaracetam occupancy of SV2A
Naganawa M, Gallezot J, Finnema S, Maguire R, Mercier J, Nabulsi N, Kervyn S, Henry S, Nicolas J, Huang Y, Chen M, Hannestad J, Klitgaard H, Stockis A, Carson R. Drug characteristics derived from kinetic modeling: combined 11C-UCB-J human PET imaging with levetiracetam and brivaracetam occupancy of SV2A. EJNMMI Research 2022, 12: 71. PMID: 36346513, PMCID: PMC9643320, DOI: 10.1186/s13550-022-00944-5.Peer-Reviewed Original ResearchTime-activity curvesBrain entryDrug concentrationsNon-human primate brainAnti-seizure activitySynaptic vesicle glycoprotein 2APlasma drug concentrationsPrevious human studiesBackgroundAntiepileptic drugsHealthy subjectsBlood samplesHuman studiesLevetiracetamPrimate brainEmission tomography dataBrivaracetamDistribution volumeArterial input functionBrainDrug characteristicsPositron emission tomography dataDrug entryFree fractionDrugsKinetic parameters k1PET Imaging of Synaptic Density: Challenges and Opportunities of Synaptic Vesicle Glycoprotein 2A PET in Small Animal Imaging
Toyonaga T, Fesharaki-Zadeh A, Strittmatter SM, Carson RE, Cai Z. PET Imaging of Synaptic Density: Challenges and Opportunities of Synaptic Vesicle Glycoprotein 2A PET in Small Animal Imaging. Frontiers In Neuroscience 2022, 16: 787404. PMID: 35345546, PMCID: PMC8957200, DOI: 10.3389/fnins.2022.787404.Peer-Reviewed Original ResearchAnimal modelsPET imaging studiesPET imagingImaging studiesSynaptic vesicle glycoprotein 2ADisease animal modelsOngoing clinical investigationsDifferent injection routesSynaptic densityClinical investigationPharmacological effectsRodent brainNovel interventionsInjection routeNeurodegenerative disordersNeuropsychiatric diseasesPET studiesBrainMultiple diseasesPET centersDiseaseInjectable volumeImagingSmaller brainsPET
2021
Lower prefrontal cortical synaptic vesicle binding in cocaine use disorder: An exploratory 11C‐UCB‐J positron emission tomography study in humans
Angarita GA, Worhunsky PD, Naganawa M, Toyonaga T, Nabulsi NB, Li C, Esterlis I, Skosnik PD, Radhakrishnan R, Pittman B, Gueorguieva R, Potenza MN, Finnema SJ, Huang Y, Carson RE, Malison RT. Lower prefrontal cortical synaptic vesicle binding in cocaine use disorder: An exploratory 11C‐UCB‐J positron emission tomography study in humans. Addiction Biology 2021, 27: e13123. PMID: 34852401, PMCID: PMC8891080, DOI: 10.1111/adb.13123.Peer-Reviewed Original ResearchConceptsCocaine use disorderAnterior cingulate cortexRecent cocaine useSynaptic densityMedial orbitofrontal cortexPrefrontal cortexCocaine useOrbitofrontal cortexUse disordersVentromedial prefrontal cortexPositron emission tomography scanPositron emission tomography studyEmission tomography scanSynaptic vesicle glycoprotein 2AHealthy control subjectsVolume of distributionEmission tomography studiesAcute cocaineControl subjectsTomography scanCocaine exposurePreclinical studiesHC subjectsDendritic spinesLifetime cocaine useAssociation of entorhinal cortical tau deposition and hippocampal synaptic density in older individuals with normal cognition and early Alzheimer's disease
Mecca AP, Chen MK, O'Dell RS, Naganawa M, Toyonaga T, Godek TA, Harris JE, Bartlett HH, Zhao W, Banks ER, Ni GS, Rogers K, Gallezot JD, Ropchan J, Emery PR, Nabulsi NB, Vander Wyk BC, Arnsten AFT, Huang Y, Carson RE, van Dyck CH. Association of entorhinal cortical tau deposition and hippocampal synaptic density in older individuals with normal cognition and early Alzheimer's disease. Neurobiology Of Aging 2021, 111: 44-53. PMID: 34963063, PMCID: PMC8761170, DOI: 10.1016/j.neurobiolaging.2021.11.004.Peer-Reviewed Original ResearchConceptsHippocampal synaptic densitySynaptic densityAlzheimer's diseaseCortical tau depositionEarly neuropathologic changesInitial clinical featuresSynaptic vesicle glycoprotein 2AEarly Alzheimer's diseaseOverall sampleEntorhinal cortical cellsClinical featuresNeuropathologic changesTau depositionTau pathologyInverse associationPerforant pathAD groupSynaptic failureNormal cognitionOlder individualsEarly degenerationDiseaseNormal participantsHippocampusTauAssessment of test-retest reproducibility of [18F]SynVesT-1, a novel radiotracer for PET imaging of synaptic vesicle glycoprotein 2A
Li S, Naganawa M, Pracitto R, Najafzadeh S, Holden D, Henry S, Matuskey D, Emery PR, Cai Z, Ropchan J, Nabulsi N, Carson RE, Huang Y. Assessment of test-retest reproducibility of [18F]SynVesT-1, a novel radiotracer for PET imaging of synaptic vesicle glycoprotein 2A. European Journal Of Nuclear Medicine And Molecular Imaging 2021, 48: 1327-1338. PMID: 33416954, DOI: 10.1007/s00259-020-05149-3.Peer-Reviewed Original ResearchConceptsTest-retest reproducibilityTime-activity curvesBPND valuesNonhuman primatesAbsolute test-retest variabilitySynaptic vesicle glycoprotein 2AHigh brain uptakeNon-displaceable binding potentialExcellent test-retest reproducibilityGray matter areasHealthy human subjectsHigh uptakeTest-retest variabilityDynamic PET scanningTest-retest reliabilityBrain uptakeDistribution volume valuesCentrum semiovaleUrinary bladderOne-tissue compartment modelMaximum SUVPET scanningPET scansTracer uptakeBrain disorders
2020
Preliminary in vivo evidence of lower hippocampal synaptic density in cannabis use disorder
D’Souza D, Radhakrishnan R, Naganawa M, Ganesh S, Nabulsi N, Najafzadeh S, Ropchan J, Ranganathan M, Cortes-Briones J, Huang Y, Carson RE, Skosnik P. Preliminary in vivo evidence of lower hippocampal synaptic density in cannabis use disorder. Molecular Psychiatry 2020, 26: 3192-3200. PMID: 32973170, DOI: 10.1038/s41380-020-00891-4.Peer-Reviewed Original ResearchConceptsHippocampal synaptic densityCannabis use disorderHealthy controlsSynaptic densityPositron emission tomographyUse disordersDSM-5 cannabis use disorderVivo evidenceAdministration of cannabinoidsHippocampal synaptic integrityVerbal memory taskSynaptic vesicle glycoprotein 2AHuman cannabis usersEffects of cannabisWarrants further studyPlasma input functionMemory taskCentrum semiovaleAdult rodentsOne-tissue compartment modelSynaptic integrityHippocampal functionCannabis misuseArterial samplingEmission tomographyIn vivo measurement of widespread synaptic loss in Alzheimer's disease with SV2A PET
Mecca AP, Chen M, O'Dell RS, Naganawa M, Toyonaga T, Godek TA, Harris JE, Bartlett HH, Zhao W, Nabulsi NB, Vander Wyk B, Varma P, Arnsten AFT, Huang Y, Carson RE, van Dyck C. In vivo measurement of widespread synaptic loss in Alzheimer's disease with SV2A PET. Alzheimer's & Dementia 2020, 16: 974-982. PMID: 32400950, PMCID: PMC7383876, DOI: 10.1002/alz.12097.Peer-Reviewed Original ResearchConceptsWidespread synaptic lossEarly Alzheimer's diseaseSynaptic lossAlzheimer's diseaseSynaptic vesicle glycoprotein 2AGray matter volumeMajor structural correlatePositron emission tomography (PET) imagingEmission Tomography ImagingDistribution volume ratioCerebellar reference regionNeocortical brain regionsSynaptic densityAD progressionConsistent pathologyPotential therapyMatter volumePromising biomarkerCognitive impairmentCN participantsBrain regionsDiseaseTomography imagingNormal participantsStructural correlatesSynaptic Changes in Parkinson Disease Assessed with in vivo Imaging
Matuskey D, Tinaz S, Wilcox KC, Naganawa M, Toyonaga T, Dias M, Henry S, Pittman B, Ropchan J, Nabulsi N, Suridjan I, Comley RA, Huang Y, Finnema SJ, Carson RE. Synaptic Changes in Parkinson Disease Assessed with in vivo Imaging. Annals Of Neurology 2020, 87: 329-338. PMID: 31953875, PMCID: PMC7065227, DOI: 10.1002/ana.25682.Peer-Reviewed Original ResearchConceptsSubstantia nigraParkinson's diseaseNormal controlsSynaptic changesPositron emission tomographic imagingSynaptic vesicle glycoprotein 2AParkinson's disease groupParkinson's disease subjectsEmission tomographic imagingPrimary brain areasAnn NeurolPostmortem autoradiographyBilateral diseaseNonmotor symptomsSynaptic lossNeuronal alterationsRelevant cortical areasStriatal dopamineBrainstem nucleiDisease groupDopamine neuronsLocus coeruleusCortical areasRed nucleusDopamine systemSynthesis and Preclinical Evaluation of an 18F‑Labeled Synaptic Vesicle Glycoprotein 2A PET Imaging Probe: [18F]SynVesT‑2
Cai Z, Li S, Zhang W, Pracitto R, Wu X, Baum E, Finnema SJ, Holden D, Toyonaga T, Lin SF, Lindemann M, Shirali A, Labaree DC, Ropchan J, Nabulsi N, Carson RE, Huang Y. Synthesis and Preclinical Evaluation of an 18F‑Labeled Synaptic Vesicle Glycoprotein 2A PET Imaging Probe: [18F]SynVesT‑2. ACS Chemical Neuroscience 2020, 11: 592-603. PMID: 31961649, DOI: 10.1021/acschemneuro.9b00618.Peer-Reviewed Original ResearchConceptsPET imaging probeHigh specific binding signalsNon-human primate brainSynaptic vesicle glycoprotein 2ATraumatic brain injuryPost-traumatic stress disorderMultiple sclerosisBrain injuryParkinson's diseasePreclinical evaluationSpecific binding signalsPrimate brainAlzheimer's diseaseNeuropsychiatric diseasesPresynaptic vesiclesStress disorderDiseaseImaging probeTransmembrane glycoproteinSclerosisPrognosisEpilepsyInjuryStrokeSV2A