2014
Tobacco smoking interferes with GABAA receptor neuroadaptations during prolonged alcohol withdrawal
Cosgrove KP, McKay R, Esterlis I, Kloczynski T, Perkins E, Bois F, Pittman B, Lancaster J, Glahn DC, O’Malley S, Carson RE, Krystal JH. Tobacco smoking interferes with GABAA receptor neuroadaptations during prolonged alcohol withdrawal. Proceedings Of The National Academy Of Sciences Of The United States Of America 2014, 111: 18031-18036. PMID: 25453062, PMCID: PMC4273348, DOI: 10.1073/pnas.1413947111.Peer-Reviewed Original ResearchMeSH KeywordsAnalysis of VarianceAnimalsCarbon RadioisotopesCravingFemaleFlumazenilHumansIodine RadioisotopesMacaca mulattaMaleNicotinePositron-Emission TomographyReceptors, GABA-ASmokingSubstance Withdrawal SyndromeTomography, Emission-Computed, Single-PhotonConceptsGABAA receptor levelsAlcohol withdrawalTobacco smokingReceptor levelsGABAA receptorsAlcohol-dependent smokersGABAA receptor availabilityMo of abstinenceProlonged alcohol withdrawalGABAA receptor systemCombination of alcoholNicotine blocksComorbid alcoholSustained elevationAlcohol abstinenceNicotine dependenceRobust elevationReceptor availabilityNicotine consumptionSmokingReceptor systemFirst weekNonhuman primatesControl levelsWithdrawal
2011
Rare Nonsynonymous Variants in Alpha-4 Nicotinic Acetylcholine Receptor Gene Protect Against Nicotine Dependence
Xie P, Kranzler HR, Krauthammer M, Cosgrove KP, Oslin D, Anton RF, Farrer LA, Picciotto MR, Krystal JH, Zhao H, Gelernter J. Rare Nonsynonymous Variants in Alpha-4 Nicotinic Acetylcholine Receptor Gene Protect Against Nicotine Dependence. Biological Psychiatry 2011, 70: 528-536. PMID: 21683344, PMCID: PMC3199609, DOI: 10.1016/j.biopsych.2011.04.017.Peer-Reviewed Original Research
2010
Decreased Beta2*‐nicotinic acetylcholine receptor availability after chronic ethanol exposure in nonhuman primates
Cosgrove KP, Kloczynski T, Bois F, Pittman B, Tamagnan G, Seibyl JP, Krystal JH, Staley JK. Decreased Beta2*‐nicotinic acetylcholine receptor availability after chronic ethanol exposure in nonhuman primates. Synapse 2010, 64: 729-732. PMID: 20340174, PMCID: PMC2904861, DOI: 10.1002/syn.20795.Peer-Reviewed Original ResearchMeSH KeywordsAnimalsAzetidinesBrainBrain ChemistryCentral Nervous System DepressantsDose-Response Relationship, DrugEthanolLinear ModelsMacaca mulattaMalePyridinesRadiopharmaceuticalsReceptors, NicotinicSelf AdministrationTomography, Emission-Computed, Single-PhotonConceptsChronic ethanol consumptionEthanol consumptionAlcohol consumptionNicotinic acetylcholine receptor availabilityAverage daily ethanol consumptionChronic ethanol exposureDaily ethanol consumptionEthanol-induced changesNicotinic acetylcholine receptorsSelf-administer ethanolIA-85380H withdrawalEthanol exposureReceptor availabilityAcetylcholine receptorsParietal cortexMale animalsTotal gramsBaselinePercent decreasePersistent changesWithdrawalMidbrainCortexAnimalsSPECT imaging of nicotinic acetylcholine receptors in nonsmoking heavy alcohol drinking individuals
Esterlis I, Cosgrove KP, Petrakis IL, McKee SA, Bois F, Krantzler E, Stiklus SM, Perry EB, Tamagnan GD, Seibyl JP, Krystal JH, Staley JK. SPECT imaging of nicotinic acetylcholine receptors in nonsmoking heavy alcohol drinking individuals. Drug And Alcohol Dependence 2010, 108: 146-150. PMID: 20074869, PMCID: PMC2871672, DOI: 10.1016/j.drugalcdep.2009.12.006.Peer-Reviewed Original ResearchMeSH KeywordsAdultAlcoholismAzetidinesFemaleHumansImage Processing, Computer-AssistedMagnetic Resonance ImagingMaleMiddle AgedPsychiatric Status Rating ScalesPyridinesRadiopharmaceuticalsReceptors, NicotinicSmokingTomography, Emission-Computed, Single-PhotonConceptsDrinks/occasionNicotinic acetylcholine receptorsControl nonsmokersAcetylcholine receptorsHeavy drinkersHeavy drinkingLast alcoholic beverageHeavy alcohol drinkersHeavy alcoholSingle photon emissionSeverity of drinkingEffect of ageTobacco smokingAlcohol drinkersAlcohol drinkingCommon neural substrateNonsmokersAlcohol consumptionReceptor availabilityLarger studyAlcohol drinksAlcohol use behaviorsAddictive disordersDrinkersNeural substrates
2009
Dopamine and Serotonin Transporter Availability During Acute Alcohol Withdrawal: Effects of Comorbid Tobacco Smoking
Cosgrove KP, Krantzler E, Frohlich EB, Stiklus S, Pittman B, Tamagnan GD, Baldwin RM, Bois F, Seibyl JP, Krystal JH, O'Malley SS, Staley JK. Dopamine and Serotonin Transporter Availability During Acute Alcohol Withdrawal: Effects of Comorbid Tobacco Smoking. Neuropsychopharmacology 2009, 34: 2218-2226. PMID: 19440191, PMCID: PMC4457331, DOI: 10.1038/npp.2009.49.Peer-Reviewed Original ResearchMeSH KeywordsAdultAlcohol DrinkingBrainBrain MappingCase-Control StudiesCocaineDopamine Plasma Membrane Transport ProteinsFemaleHumansMagnetic Resonance ImagingMaleMiddle AgedProtein BindingRadiopharmaceuticalsSerotonin Plasma Membrane Transport ProteinsSmokingStatistics as TopicSubstance Withdrawal SyndromeTomography, Emission-Computed, Single-PhotonYoung AdultConceptsDA transporter availabilityTobacco smokingSerotonin transporter availabilityTransporter availabilityAlcohol drinkersAcute withdrawalAlcohol drinkingLast drinkCIT single photon emissionAcute alcohol withdrawalHeavy alcohol drinkingSingle photon emissionEffects of alcoholControl smokersAlcohol withdrawalSynaptic markersNeuroadaptive changesNonsmokersSmokersSmokingTotal groupBrainstemSignificant positive correlationFirst weekPrevious month
2008
β 2 Nicotinic acetylcholine receptor availability in post-traumatic stress disorder
Czermak C, Staley JK, Kasserman S, Bois F, Young T, Henry S, Tamagnan GD, Seibyl JP, Krystal JH, Neumeister A. β 2 Nicotinic acetylcholine receptor availability in post-traumatic stress disorder. The International Journal Of Neuropsychopharmacology 2008, 11: 419-424. PMID: 18190729, DOI: 10.1017/s1461145707008152.Peer-Reviewed Original ResearchMeSH KeywordsAdultAnalysis of VarianceAzetidinesBrainFemaleHumansIodine RadioisotopesMagnetic Resonance ImagingMaleMiddle AgedPyridinesReceptors, NicotinicStress Disorders, Post-TraumaticTomography, Emission-Computed, Single-PhotonTrauma Severity IndicesConceptsPost-traumatic stress disorderClinician-Administered PTSD ScaleMesiotemporal cortexPTSD patientsPathophysiology of PTSDStress disorderBeta2 nAChRsNicotinic acetylcholine receptor availabilityHistory of smokingHealthy control subjectsNicotinic acetylcholine receptorsIA bindingNovel molecular targetsSingle photon emissionSubgroup of participantsRe-experiencing symptom clusterIA-85380Symptomatic patientsControl subjectsHealthy controlsReceptor availabilityPTSD ScaleAcetylcholine receptorsSymptom clustersPrefrontal cortexRelationship between ketamine-induced psychotic symptoms and NMDA receptor occupancy—a [123I]CNS-1261 SPET study
Stone JM, Erlandsson K, Arstad E, Squassante L, Teneggi V, Bressan RA, Krystal JH, Ell PJ, Pilowsky LS. Relationship between ketamine-induced psychotic symptoms and NMDA receptor occupancy—a [123I]CNS-1261 SPET study. Psychopharmacology 2008, 197: 401-408. PMID: 18176855, DOI: 10.1007/s00213-007-1047-x.Peer-Reviewed Original ResearchMeSH KeywordsAdultBrief Psychiatric Rating ScaleDose-Response Relationship, DrugGuanidinesHumansInfusions, IntravenousIodine RadioisotopesKetamineMalePrefrontal CortexPsychoses, Substance-InducedReceptors, N-Methyl-D-AspartateSchizophreniaSingle-Blind MethodTomography, Emission-Computed, Single-PhotonConceptsBrief Psychiatric Rating ScaleVolume of distributionNMDA receptorsPsychotic symptomsN-methyl-D-aspartate receptorsKetamine-induced psychotic symptomsSingle photon emission tomographyNMDA receptor bindingEffects of ketamineNegative subscaleHealthy human controlsPsychiatric Rating ScaleNegative psychotic symptomsInferior frontal cortexKetamine administrationBolus infusionHealthy controls
2007
Imaging the Neurochemistry of Alcohol and Substance Abuse
Martinez D, Kim JH, Krystal J, Abi-Dargham A. Imaging the Neurochemistry of Alcohol and Substance Abuse. Neuroimaging Clinics Of North America 2007, 17: 539-555. PMID: 17983969, DOI: 10.1016/j.nic.2007.07.004.Peer-Reviewed Original ResearchMeSH KeywordsAlcoholismHumansPositron-Emission TomographySubstance-Related DisordersTomography, Emission-Computed, Single-Photon
2005
First in vivo evidence of an NMDA receptor deficit in medication-free schizophrenic patients
Pilowsky LS, Bressan RA, Stone JM, Erlandsson K, Mulligan RS, Krystal JH, Ell PJ. First in vivo evidence of an NMDA receptor deficit in medication-free schizophrenic patients. Molecular Psychiatry 2005, 11: 118-119. PMID: 16189506, DOI: 10.1038/sj.mp.4001751.Peer-Reviewed Original ResearchCortical γ-Aminobutyric Acid Type A–Benzodiazepine Receptors in Recovery From Alcohol Dependence: Relationship to Features of Alcohol Dependence and Cigarette Smoking
Staley JK, Gottschalk C, Petrakis IL, Gueorguieva R, O’Malley S, Baldwin R, Jatlow P, Verhoeff NP, Perry E, Weinzimmer D, Frohlich E, Ruff E, van Dyck CH, Seibyl JP, Innis RB, Krystal JH. Cortical γ-Aminobutyric Acid Type A–Benzodiazepine Receptors in Recovery From Alcohol Dependence: Relationship to Features of Alcohol Dependence and Cigarette Smoking. JAMA Psychiatry 2005, 62: 877-888. PMID: 16061765, DOI: 10.1001/archpsyc.62.8.877.Peer-Reviewed Original ResearchMeSH KeywordsAdultAlcoholismCerebral CortexComorbidityEthanolFlumazenilHumansIodine RadioisotopesMaleReceptors, GABA-ASmokingSubstance Withdrawal SyndromeTemperanceTomography, Emission-Computed, Single-PhotonConceptsWeeks of abstinenceIomazenil single-photon emissionSingle photon emissionDays of sobrietyAlcohol dependenceIomazenil uptakeTomographic scanBenzodiazepine receptorsVoxel-based statistical parametric mappingReceptor adaptationDistribution volumeReceptor functionGamma-aminobutyric acid type ABenzodiazepine receptor levelsIodine I 123Reduced receptor functionHuman alcohol dependenceLast alcoholic drinkHealthy comparison groupStatistical parametric mappingAlcohol withdrawalClinical featuresSmoking statusCigarette smokingAcute withdrawalImpact of Schizophrenia and Chronic Antipsychotic Treatment on [123I]CNS-1261 Binding to N-Methyl-D-Aspartate Receptors In Vivo
Bressan RA, Erlandsson K, Stone JM, Mulligan RS, Krystal JH, Ell PJ, Pilowsky LS. Impact of Schizophrenia and Chronic Antipsychotic Treatment on [123I]CNS-1261 Binding to N-Methyl-D-Aspartate Receptors In Vivo. Biological Psychiatry 2005, 58: 41-46. PMID: 15992521, DOI: 10.1016/j.biopsych.2005.03.016.Peer-Reviewed Original ResearchMeSH KeywordsAdultAntipsychotic AgentsClozapineDose-Response Relationship, DrugFemaleGuanidinesHumansIodine RadioisotopesMaleReceptors, N-Methyl-D-AspartateSchizophreniaTomography, Emission-Computed, Single-PhotonConceptsHealthy control subjectsTypical antipsychoticsControl subjectsN-methyl-D-aspartate receptor functionN-methyl-D-aspartate receptorsAntipsychotic drug discoveryChronic antipsychotic treatmentDrug-free patientsImpact of schizophreniaNMDA receptor activityHealthy normal volunteersClozapine treatmentAntipsychotic treatmentGlutamatergic systemPatient groupAntipsychotic drugsNonsignificant reductionNMDA receptorsNormal volunteersSchizophrenia patientsControl groupReceptor activityBrain regionsReceptor functionTomography radiotracer
2001
CURRENT PERSPECTIVES ON THE PATHOPHYSIOLOGY OF SCHIZOPHRENIA, DEPRESSION, AND ANXIETY DISORDERS
Krystal J, D'Souza D, Sanacora G, Goddard A, Charney D. CURRENT PERSPECTIVES ON THE PATHOPHYSIOLOGY OF SCHIZOPHRENIA, DEPRESSION, AND ANXIETY DISORDERS. Medical Clinics Of North America 2001, 85: 559-577. PMID: 11349473, DOI: 10.1016/s0025-7125(05)70329-1.Peer-Reviewed Original ResearchMeSH KeywordsAnxiety DisordersBiological PsychiatryDepressive DisorderHumansMagnetic Resonance ImagingMagnetic Resonance SpectroscopyNeurobiologyNeurochemistryResearchSchizophreniaTomography, Emission-ComputedTomography, Emission-Computed, Single-Photon
2000
Dopamine and serotonin transporters in patients with schizophrenia: an imaging study with [123I]β-CIT
Laruelle M, Abi-Dargham A, van Dyck C, Gil R, D’Souza D, Krystal J, Seibyl J, Baldwin R, Innis R. Dopamine and serotonin transporters in patients with schizophrenia: an imaging study with [123I]β-CIT. Biological Psychiatry 2000, 47: 371-379. PMID: 10704949, DOI: 10.1016/s0006-3223(99)00257-7.Peer-Reviewed Original ResearchMeSH KeywordsAdultAge FactorsBrain StemCarrier ProteinsCase-Control StudiesCocaineDopamineDopamine Plasma Membrane Transport ProteinsFemaleHumansIodine RadioisotopesMaleMembrane GlycoproteinsMembrane Transport ProteinsMiddle AgedNeostriatumNerve Tissue ProteinsSchizophreniaSerotoninSerotonin Plasma Membrane Transport ProteinsTomography, Emission-Computed, Single-PhotonConceptsAmphetamine-induced dopamine releaseStriatal dopamine transporterDopamine transporterControl subjectsDAT densityDopamine releaseNegative symptomsStriatal DAT densityDuration of illnessDopamine nerve terminalsHealthy control subjectsSerotonin transporter densityCohort of subjectsRelative deficitSingle photon emissionNeurodegenerative processesPostmortem studiesNerve terminalsSerotonin functionTrend-level associationReceptor radiotracerPatientsDopamine functionLower striatalTransporter densityImpairment of GABAergic Transmission in Depression: New Insights from Neuroimaging Studies
Sanacora G, Mason G, Krystal J. Impairment of GABAergic Transmission in Depression: New Insights from Neuroimaging Studies. Critical Reviews In Neurobiology 2000, 14: 23. PMID: 11253954, DOI: 10.1615/critrevneurobiol.v14.i1.20.Peer-Reviewed Reviews, Practice Guidelines, Standards, and Consensus StatementsMeSH KeywordsAnimalsAntidepressive AgentsBrainDepressive DisorderHumansMagnetic Resonance SpectroscopyRatsReceptors, GABATomography, Emission-ComputedTomography, Emission-Computed, Single-PhotonConceptsNeurobiology of depressionGABAergic functionTechnique of PETCSF GABA concentrationsGABA-mimetic agentsNovel neuroimaging techniquesNondepressed comparison subjectsMood stabilizingChronic administrationGABAergic transmissionGABAergic neurotransmissionAntidepressant propertiesGABAergic abnormalitiesDepressed patientsAntidepressant drugsDisorder pathophysiologyLower plasmaComparison subjectsAnimal studiesGABAergic contributionGABA concentrationNovel imaging techniqueNeuroimaging studiesNeuroimaging techniquesDepression
1999
[123I]Iomazenil SPECT benzodiazepine receptor imaging in schizophrenia
Verhoeff N, Soares J, D’Souza C, Gil R, Degen K, Abi-Dargham A, Zoghbi S, Fujita M, Rajeevan N, Seibyl J, Krystal J, van Dyck C, Charney D, Innis R. [123I]Iomazenil SPECT benzodiazepine receptor imaging in schizophrenia. Psychiatry Research 1999, 91: 163-173. PMID: 10641580, DOI: 10.1016/s0925-4927(99)00027-x.Peer-Reviewed Original ResearchMeSH KeywordsAdultBrainBrain MappingCerebral CortexDominance, CerebralFemaleFlumazenilFrontal LobeHumansIodine RadioisotopesMaleMiddle AgedPsychiatric Status Rating ScalesReceptors, GABA-ASchizophreniaTomography, Emission-Computed, Single-PhotonConceptsDuration of illnessHealthy control subjectsControl subjectsGamma-aminobutyric acidLeft precentral gyrusSuperior occipital gyrusPANSS scoresPrecentral gyrusOccipital gyrusSignificant differencesTotal brain uptakeNon-smoking patientsGray matter atrophyConstant infusion paradigmPathophysiology of schizophreniaCortical brain regionsSingle photon emissionTypical antipsychoticsAtypical antipsychoticsCigarette smokingInhibitory neurotransmissionBrain uptakeInfusion paradigmMatter atrophyPostmortem studiesNo Evidence of Altered In Vivo Benzodiazepine Receptor Binding in Schizophrenia
Abi-Dargham A, Laruelle M, Krystal J, D'Souza C, Zoghbi S, Baldwin R, Seibyl J, Mawlawi O, de Erasquin G, Charney D, Innis R. No Evidence of Altered In Vivo Benzodiazepine Receptor Binding in Schizophrenia. Neuropsychopharmacology 1999, 20: 650-661. PMID: 10327433, DOI: 10.1016/s0893-133x(98)00107-9.Peer-Reviewed Original ResearchMeSH KeywordsAdultFlumazenilHumansIodine RadioisotopesMagnetic Resonance ImagingMaleMiddle AgedOutcome Assessment, Health CareReceptors, GABA-ASchizophreniaTomography, Emission-Computed, Single-PhotonConceptsReceptor densitySchizophrenic patientsVivo benzodiazepine receptor bindingBDZ receptor densityMale schizophrenic patientsBenzodiazepine receptor densityPathophysiology of schizophreniaBenzodiazepine receptor bindingSingle photon emissionRegional distribution volumesPrevious postmortemGABA transmissionBDZ antagonistBDZ receptorsReceptor expressionNeurotransmitter systemsHealthy volunteersPsychotic symptomsBrain regionsDistribution volumeReceptor bindingSchizophreniaVivo studiesPatientsPossible alterationsChanges of benzodiazepine receptors during chronic benzodiazepine administration in humans
Fujita M, Woods S, Verhoeff N, Abi-Dargham A, Baldwin R, Zoghbi S, Soares J, Jatlow P, Krystal J, Rajeevan N, Charney D, Seibyl J, Innis R. Changes of benzodiazepine receptors during chronic benzodiazepine administration in humans. European Journal Of Pharmacology 1999, 368: 161-172. PMID: 10193652, DOI: 10.1016/s0014-2999(99)00013-8.Peer-Reviewed Original ResearchMeSH KeywordsAdministration, OralAdultAlprazolamAnti-Anxiety AgentsFemaleFlumazenilHumansIodine RadioisotopesMaleMiddle AgedNeuropsychological TestsReceptors, GABA-AReproducibility of ResultsTomography, Emission-Computed, Single-PhotonTreatment OutcomeVerbal LearningConceptsClinical effectsReceptor levelsReceptor densityReceptor occupancyChronic benzodiazepine administrationBenzodiazepine receptor densityHealthy human subjectsComparison of baselineSingle photon emissionHopkins Verbal Learning TestInduced sedationVerbal Learning TestBenzodiazepine administrationOral administrationBaseline valuesBenzodiazepine receptorsTolerance developmentDay 3Day 17Day 4Day 10Central typeLearning TestReceptorsHuman subjects
1998
Alterations of Benzodiazepine Receptors in Type II Alcoholic Subjects Measured With SPECT and 123IIomazenil
Abi-Dargham A, Krystal JH, Anjilvel S, Scanley BE, Zoghbi S, Baldwin RM, Rajeevan N, Ellis S, Petrakis IL, Seibyl JP, Charney DS, Laruelle M, Innis RB. Alterations of Benzodiazepine Receptors in Type II Alcoholic Subjects Measured With SPECT and 123IIomazenil. American Journal Of Psychiatry 1998, 155: 1550-1555. PMID: 9812116, DOI: 10.1176/ajp.155.11.1550.Peer-Reviewed Original ResearchMeSH KeywordsAdultAlcoholismBrainCerebellumCerebral CortexFlumazenilFrontal LobeGyrus CinguliHumansImage Processing, Computer-AssistedIodine RadioisotopesMagnetic Resonance ImagingMaleReceptors, GABA-ARisk FactorsTomography, Emission-Computed, Single-PhotonConceptsHealthy comparison subjectsBenzodiazepine receptorsComparison subjectsAlcoholic subjectsDistribution volumeAlcoholic patientsAnterior cingulateBenzodiazepine receptor densityRight middle frontal gyrusLeft occipital cortexType II alcoholismSingle photon emissionMiddle frontal gyrusStatistical parametric mappingContinuous infusionReceptor radiotracerReceptor densityOccipital cortexCerebellar cortexCortical regionsPatientsFrontal gyrusInterest analysisVivo studiesParametric mappingIncreased Striatal Dopamine Transmission in Schizophrenia: Confirmation in a Second Cohort
Abi-Dargham A, Gil R, Krystal J, Baldwin RM, Seibyl JP, Bowers M, van Dyck CH, Charney DS, Innis RB, Laruelle M. Increased Striatal Dopamine Transmission in Schizophrenia: Confirmation in a Second Cohort. American Journal Of Psychiatry 1998, 155: 761-767. PMID: 9619147, DOI: 10.1176/ajp.155.6.761.Peer-Reviewed Original ResearchMeSH KeywordsAdultAmphetamineBenzamidesCohort StudiesCorpus StriatumDopamineFemaleHumansMaleMiddle AgedPyrrolidinesReceptors, DopamineReproducibility of ResultsSchizophreniaSynaptic TransmissionTomography, Emission-Computed, Single-PhotonConceptsD2 receptor availabilityAcute amphetamine challengeStriatal dopamine transmissionAmphetamine challengeReceptor availabilityDopamine releaseHealthy subjectsDopamine transmissionDopamine D2 receptor availabilityExcess dopamine releaseStriatal dopamine releaseComparison groupD2 receptor radiotracerHistory of alcoholDSM-IV criteriaSingle photon emissionNew cohortUntreated patientsReceptor radiotracerSchizophrenic patientsPatientsSecond cohortParental socioeconomic statusPositive symptomsSubstance abuse
1996
Single photon emission computerized tomography imaging of amphetamine-induced dopamine release in drug-free schizophrenic subjects.
Laruelle M, Abi-Dargham A, van Dyck CH, Gil R, D'Souza CD, Erdos J, McCance E, Rosenblatt W, Fingado C, Zoghbi SS, Baldwin RM, Seibyl JP, Krystal JH, Charney DS, Innis RB. Single photon emission computerized tomography imaging of amphetamine-induced dopamine release in drug-free schizophrenic subjects. Proceedings Of The National Academy Of Sciences Of The United States Of America 1996, 93: 9235-9240. PMID: 8799184, PMCID: PMC38625, DOI: 10.1073/pnas.93.17.9235.Peer-Reviewed Original ResearchMeSH KeywordsAdultAmphetamineAnimalsBenzamidesCorpus StriatumDopamineDopamine AntagonistsFemaleHumansMalePapioPsychoses, Substance-InducedPyrrolidinesReceptors, Dopamine D2SchizophreniaTomography, Emission-Computed, Single-PhotonConceptsAmphetamine-induced dopamine releaseDopamine releaseDopaminergic transmissionPsychotic symptomsSchizophrenic groupDopamine D2 receptor availabilityAmphetamine-induced decreaseAmphetamine-induced reductionD2 receptor availabilityD2 receptor radiotracerPositive psychotic symptomsSingle photon emissionExaggerated stimulationAbnormal responsivenessDopaminergic neuronsHealthy controlsReceptor radiotracerSchizophrenic patientsDopamine hypothesisDopamine functionReceptor availabilityAmphetamine effectsControl groupSchizophrenic subjectsSchizophrenia