2024
In Vivo Synaptic Density in Early Schizophrenia: Are There No Differences or Are They Too Small to Detect?
Radhakrishnan R. In Vivo Synaptic Density in Early Schizophrenia: Are There No Differences or Are They Too Small to Detect? Biological Psychiatry 2024, 95: 605-607. PMID: 38479976, DOI: 10.1016/j.biopsych.2024.01.016.Peer-Reviewed Original ResearchConceptsSynaptic density
2022
The association between cannabis use and facial emotion recognition in schizophrenia, siblings, and healthy controls: Results from the EUGEI study
Fusar-Poli L, Pries LK, van Os J, Radhakrishnan R, Pençe AY, Erzin G, Delespaul P, Kenis G, Luykx JJ, Lin BD, Akdede B, Binbay T, Altınyazar V, Yalınçetin B, Gümüş-Akay G, Cihan B, Soygür H, Ulaş H, Cankurtaran EŞ, Kaymak SU, Mihaljevic MM, Andric-Petrovic S, Mirjanic T, Bernardo M, Mezquida G, Amoretti S, Bobes J, Saiz PA, García-Portilla MP, Sanjuan J, Aguilar EJ, Santos JL, Jiménez-López E, Arrojo M, Carracedo A, López G, González-Peñas J, Parellada M, Maric NP, Atbaşoğlu C, Üçok A, Alptekin K, Saka MC, investigators G, Aguglia E, Arango C, Rutten BP, Guloksuz S. The association between cannabis use and facial emotion recognition in schizophrenia, siblings, and healthy controls: Results from the EUGEI study. European Neuropsychopharmacology 2022, 63: 47-59. PMID: 36055075, DOI: 10.1016/j.euroneuro.2022.08.003.Peer-Reviewed Original ResearchConceptsHealthy controlsCannabis useDegraded Facial Affect Recognition TaskPresent cross-sectional studyCross-sectional studyHigh genetic riskProgression of schizophreniaRegular cannabis useCognitive disturbancesRegular cannabisPsychosis riskPatientsSchizophreniaFacial emotion recognition performanceGenetic riskCannabisCurrent cannabisEUGEI studyLongitudinal studyAgeSiblingsAssociationRiskOnsetEffect relationship
2021
Dopamine D1R Receptor Stimulation as a Mechanistic Pro-cognitive Target for Schizophrenia
Abi-Dargham A, Javitch JA, Slifstein M, Anticevic A, Calkins ME, Cho YT, Fonteneau C, Gil R, Girgis R, Gur RE, Gur RC, Grinband J, Kantrowitz J, Kohler C, Krystal J, Murray J, Ranganathan M, Santamauro N, Van Snellenberg J, Tamayo Z, Wolf D, D’Souza D, Srihari V, Gueorguieva R, Patel P, Forselius-Bielen K, Lu J, Butler A, Fram G, Afriyie-Agyemang Y, Selloni A, Cadavid L, Gomez-Luna S, Gupta A, Radhakrishnan R, Rashid A, Aker R, Abrahim P, Nia A, Surti T, Kegeles L, Carlson M, Goldberg T, Gangwisch J, Benedict E, Govil P, Brazis S, Mayer M, de la Garrigue N, Fallon N, Baumvoll T, Abeykoon S, Perlman G, Bobchin K, Elliott M, Schmidt L, Rush S, Port A, Heffernan Z, Laney N, Kantor J, Hohing T, Gray D, Lieberman J. Dopamine D1R Receptor Stimulation as a Mechanistic Pro-cognitive Target for Schizophrenia. Schizophrenia Bulletin 2021, 48: 199-210. PMID: 34423843, PMCID: PMC8781338, DOI: 10.1093/schbul/sbab095.Peer-Reviewed Original ResearchConceptsCortical dopamine neurotransmissionPositive allosteric modulationImportant therapeutic targetPF-06412562Dopaminergic receptorsD1R stimulationDA levelsTolerable dosesLevel of stimulationDopamine neurotransmissionReceptor stimulationTherapeutic targetPartial agonistCognitive deficitsBiased agonismFull agonismTarget engagementAllosteric modulationNew drugsStimulationPoor bioavailabilitySchizophreniaOptimal stimulationDrugsExpression levelsIn vivo evidence of lower synaptic vesicle density in schizophrenia
Radhakrishnan R, Skosnik PD, Ranganathan M, Naganawa M, Toyonaga T, Finnema S, Hillmer AT, Esterlis I, Huang Y, Nabulsi N, Carson RE, D’Souza D. In vivo evidence of lower synaptic vesicle density in schizophrenia. Molecular Psychiatry 2021, 26: 7690-7698. PMID: 34135473, DOI: 10.1038/s41380-021-01184-0.Peer-Reviewed Original ResearchMeSH KeywordsBrainHumansNerve Tissue ProteinsPositron-Emission TomographySchizophreniaSynaptic VesiclesConceptsSynaptic vesicle densityHealthy controlsVesicle densityHigh-resolution research tomographySynaptic densitySCZ patientsVivo measuresNovel positron emission tomography (PET) ligandGender-matched healthy controlsCumulative antipsychotic exposurePositron emission tomography (PET) ligandSynaptic spine densityPsychosis symptom severityGray matter volumeJ bindingAntipsychotic exposureSpine densityDisease progressionFrontal cortexOccipital cortexTomography ligandTemporal cortexAnterior cingulateVivo findingsParietal cortex
2019
In vivo 5-HT6 and 5-HT2A receptor availability in antipsychotic treated schizophrenia patients vs. unmedicated healthy humans measured with [11C]GSK215083 PET
Radhakrishnan R, Matuskey D, Nabulsi N, Gaiser E, Gallezot JD, Henry S, Planeta B, Lin SF, Ropchan J, Huang Y, Carson RE, D'Souza DC. In vivo 5-HT6 and 5-HT2A receptor availability in antipsychotic treated schizophrenia patients vs. unmedicated healthy humans measured with [11C]GSK215083 PET. Psychiatry Research Neuroimaging 2019, 295: 111007. PMID: 31760336, DOI: 10.1016/j.pscychresns.2019.111007.Peer-Reviewed Original ResearchConceptsHealthy male controlsPositron emission tomographyMultilinear analysis 1Antipsychotic treatmentLower BPFrontal cortexReceptor availabilityAge-matched healthy male controlsDifferent second-generation antipsychoticsSteady-state troughPeak serum levelsSecond-generation antipsychoticsPotential therapeutic targetMale patientsSerum levelsHealthy humansTherapeutic targetSchizophrenia patientsTime-activity curvesMale controlsCognitive impairmentEmission tomographyVentral striatumPatientsSchizophrenia
2012
Feasibility, Safety, and Efficacy of the Combination of D-Serine and Computerized Cognitive Retraining in Schizophrenia: An International Collaborative Pilot Study
D'Souza DC, Radhakrishnan R, Perry E, Bhakta S, Singh NM, Yadav R, Abi-Saab D, Pittman B, Chaturvedi SK, Sharma MP, Bell M, Andrade C. Feasibility, Safety, and Efficacy of the Combination of D-Serine and Computerized Cognitive Retraining in Schizophrenia: An International Collaborative Pilot Study. Neuropsychopharmacology 2012, 38: 492-503. PMID: 23093223, PMCID: PMC3547200, DOI: 10.1038/npp.2012.208.Peer-Reviewed Original ResearchConceptsCognitive retrainingCognitive deficitsVerbal Working MemoryCognitive remediation strategiesAttention/vigilanceBasic information processingIndividual test performanceGlobal cognitive indexWorking memoryD-serineCognitive indicesCombination of pharmacotherapyTest performanceInformation processingMulticenter international clinical trialParallel group designSchizophrenia subjectsCollaborative pilot studyInternational clinical trialsUS samplePreliminary findingsCombination pharmacotherapySchizophreniaClinical trialsOutcome measures