2001
Quantitative functional imaging of the brain: towards mapping neuronal activity by BOLD fMRI
Hyder F, Kida I, Behar K, Kennan R, Maciejewski P, Rothman D. Quantitative functional imaging of the brain: towards mapping neuronal activity by BOLD fMRI. NMR In Biomedicine 2001, 14: 413-431. PMID: 11746934, DOI: 10.1002/nbm.733.Peer-Reviewed Original ResearchConceptsMagnetic resonance imagingNeuronal activityBOLD functional MRIFunctional MRICerebral cortexPharmacological treatmentGlutamate release inhibitorNeuronal glucose oxidationRat cerebral cortexRelease of glutamateRat forepaw stimulation modelFMRI signalsFunctional magnetic resonance imagingQuantitative magnetic resonance imagingBlood oxygenation levelBOLD fMRI studiesEnergy metabolismBOLD fMRI signalMulti-modal magnetic resonance imagingGlutamatergic neuronsRelease inhibitorChannel blockersRat brainOxygen deliveryNeurochemical basisInhibition of Voltage-Dependent Sodium Channels Suppresses the Functional Magnetic Resonance Imaging Response to Forepaw Somatosensory Activation in the Rodent
Kida I, Hyder F, Behar K. Inhibition of Voltage-Dependent Sodium Channels Suppresses the Functional Magnetic Resonance Imaging Response to Forepaw Somatosensory Activation in the Rodent. Cerebrovascular And Brain Metabolism Reviews 2001, 21: 585-591. PMID: 11333369, DOI: 10.1097/00004647-200105000-00013.Peer-Reviewed Original ResearchConceptsMagnetic resonance imaging responseSomatosensory activationFunctional magnetic resonance imaging (fMRI) responsesForepaw stimulationLamotrigine treatmentImaging responseGlutamate release inhibitorBOLD fMRI responsesFunctional imaging signalsBOLD fMRI signal changesFMRI signal changesTime-dependent mannerBaseline CBFAbsence of stimulationSomatosensory cortexRelease inhibitorChannel blockersRat cortexNeurotransmitter cycleBlood flow experimentsFMRI responsesBOLD fMRIStimulationLamotrigineTreatmentIn vivo13C NMR measurement of neurotransmitter glutamate cycling, anaplerosis and TCA cycle flux in rat brain during [2‐13C]glucose infusion
Sibson N, Mason G, Shen J, Cline G, Herskovits A, Wall J, Behar K, Rothman D, Shulman R. In vivo13C NMR measurement of neurotransmitter glutamate cycling, anaplerosis and TCA cycle flux in rat brain during [2‐13C]glucose infusion. Journal Of Neurochemistry 2001, 76: 975-989. PMID: 11181817, DOI: 10.1046/j.1471-4159.2001.00074.x.Peer-Reviewed Original ResearchConceptsGlutamate/glutamine cyclingCerebral cortexAstrocytic tricarboxylic acid cycleGlutamine cyclingRat cerebral cortexGlutamine synthesisDe novo glutamine synthesisAnesthetized ratsRat brainNeurotransmitter glutamateHyperammonemic conditionsGlutamate cyclingInfusionGlutamate precursorCortexBrainTCA cycle fluxAnaplerosisMajor metabolic fluxTricarboxylic acid cycleCycle flux
2000
Brain regional development of the activity of α-ketoglutarate dehydrogenase complex in the rat
Buerstatte C, Behar K, Novotny E, Lai J. Brain regional development of the activity of α-ketoglutarate dehydrogenase complex in the rat. Brain Research 2000, 125: 139-145. PMID: 11154769, DOI: 10.1016/s0165-3806(00)00134-6.Peer-Reviewed Original ResearchConceptsAdult levelsKGDHC activityCerebral cortexOlfactory bulbPostnatal day 2Age-dependent increaseGlucose oxidative metabolismAlpha-ketoglutarate dehydrogenase complex activityRat brainDay 2Pathophysiological implicationsPostnatal developmentDistinct region-specific patternsNeurotransmitter synthesisRegion-specific patternsOxidative metabolismDehydrogenase complex activityHippocampusStriatumEnergy metabolismCerebellumP30TCA cycle fluxP17P10Dependence of Oxygen Delivery on Blood Flow in Rat Brain: A 7 Tesla Nuclear Magnetic Resonance Study
Hyder F, Kennan R, Kida I, Mason G, Behar K, Rothman D. Dependence of Oxygen Delivery on Blood Flow in Rat Brain: A 7 Tesla Nuclear Magnetic Resonance Study. Cerebrovascular And Brain Metabolism Reviews 2000, 20: 485-498. PMID: 10724113, DOI: 10.1097/00004647-200003000-00007.Peer-Reviewed Original ResearchConceptsMagnetic resonance imagingCapillary bedOxygen deliveryML xCerebral oxygen deliveryNicotine hydrogen tartrateRespective control conditionsValues of CBFMorphine anesthesiaSensorimotor cortexForepaw stimulationSodium pentobarbitalRat brainBlood flowCMRO2Mature ratsCortical activityResonance imagingBasal conditionsPercentage changeRatsAdministrationCBF
1999
New NMR measurements in epilepsy. Measuring brain GABA in patients with complex partial seizures.
Petroff O, Behar K, Rothman D. New NMR measurements in epilepsy. Measuring brain GABA in patients with complex partial seizures. Advances In Neurology 1999, 79: 939-45. PMID: 10514877.Peer-Reviewed Original Research
1998
Functional Energy Metabolism:In vivo 13C-NMR Spectroscopy Evidence for Coupling of Cerebral Glucose Consumption and Gl utamatergic Neuronal Activity
Sibson N, Shen J, Mason G, Rothman D, Behar K, Shulman R. Functional Energy Metabolism:In vivo 13C-NMR Spectroscopy Evidence for Coupling of Cerebral Glucose Consumption and Gl utamatergic Neuronal Activity. Developmental Neuroscience 1998, 20: 321-330. PMID: 9778568, DOI: 10.1159/000017327.Peer-Reviewed Original ResearchConceptsRat brain cortexGlucose metabolismBrain cortexNeurotransmitter cyclingTotal glucose oxidationGlutamatergic synaptic activityCerebral glucose consumptionCerebral glucose metabolismFunctional activityFunctional imaging methodsGlucose oxidationOxidative glucose metabolismGlutamate neurotransmitter cyclingSynaptic activityNeuronal activityMild anesthesiaGlutamine synthesisMammalian brainNeurotransmitter releaseGlutamate cyclingEEG activityAmmonia metabolismNeurophysiological basisDetoxification componentsVivo results15N-NMR Spectroscopy Studies of Ammonia Transport and Glutamine Synthesis in the Hyperammonemic Rat Brain
Shen J, Sibson N, Cline G, Behar K, Rothman D, Shulman R. 15N-NMR Spectroscopy Studies of Ammonia Transport and Glutamine Synthesis in the Hyperammonemic Rat Brain. Developmental Neuroscience 1998, 20: 434-443. PMID: 9778582, DOI: 10.1159/000017341.Peer-Reviewed Original Research
1997
Oxidative Glucose Metabolism in Rat Brain During Single Forepaw Stimulation: A Spatially Localized 1H[13C] Nuclear Magnetic Resonance Study
Hyder F, Rothman* D, Mason† G, Rangarajan A, Behar‡ K, Shulman R. Oxidative Glucose Metabolism in Rat Brain During Single Forepaw Stimulation: A Spatially Localized 1H[13C] Nuclear Magnetic Resonance Study. Cerebrovascular And Brain Metabolism Reviews 1997, 17: 1040-1047. PMID: 9346428, DOI: 10.1097/00004647-199710000-00005.Peer-Reviewed Original ResearchIn vivo 13C NMR measurements of cerebral glutamine synthesis as evidence for glutamate–glutamine cycling
Sibson N, Dhankhar A, Mason G, Behar K, Rothman D, Shulman R. In vivo 13C NMR measurements of cerebral glutamine synthesis as evidence for glutamate–glutamine cycling. Proceedings Of The National Academy Of Sciences Of The United States Of America 1997, 94: 2699-2704. PMID: 9122259, PMCID: PMC20152, DOI: 10.1073/pnas.94.6.2699.Peer-Reviewed Original Research
1996
The13C isotope and nuclear magnetic resonance: unique tools for the study of brain metabolism
Mason G, Behar K, Lai J. The13C isotope and nuclear magnetic resonance: unique tools for the study of brain metabolism. Metabolic Brain Disease 1996, 11: 283-313. PMID: 8979250, DOI: 10.1007/bf02029492.Peer-Reviewed Reviews, Practice Guidelines, Standards, and Consensus StatementsLow brain GABA level is associated with poor seizure control
Petroff O, Rothman D, Behar K, Mattson R. Low brain GABA level is associated with poor seizure control. Annals Of Neurology 1996, 40: 908-911. PMID: 9007096, DOI: 10.1002/ana.410400613.Peer-Reviewed Original ResearchConceptsLower GABA levelsBrain GABA levelsLower brain GABA levelsPoor seizure controlGABA levelsSeizure controlRecent seizuresGamma-aminobutyric acid concentrationComplex partial seizuresPartial seizuresEpileptic syndromesEpileptic focusOccipital lobeCerebrospinal fluidPatientsSeizuresSignificant associationMagnetic resonanceVivo measurementsSurface coilLevelsEpilepsySyndromeGABAAcid concentrationHuman brain GABA levels rise rapidly after initiation of vigabatrin therapy
Petroff O, Rothman D, Behar K, Collins T, Mattson R. Human brain GABA levels rise rapidly after initiation of vigabatrin therapy. Neurology 1996, 47: 1567-1571.. PMID: 8960747, DOI: 10.1212/wnl.47.6.1567.Peer-Reviewed Original ResearchConceptsBrain GABA levelsBrain GABASingle oral doseOral doseGABA levelsSide effectsHuman brain GABA levelsEffective antiepileptic medicationsHours of administrationAntiepileptic medicationsVigabatrin therapyDay dosingIntractable epilepsySerial measurementsOccipital cortexVigabatrinDay 8Day 5GABAGABA transaminasePatientsDoseNext dayHuman brainMagnetic resonance spectroscopyShort echo time proton magnetic resonance spectroscopic imaging of macromolecule and metabolite signal intensities in the human brain
Hwang J, Graham G, Behar K, Alger J, Prichard J, Rothman D. Short echo time proton magnetic resonance spectroscopic imaging of macromolecule and metabolite signal intensities in the human brain. Magnetic Resonance In Medicine 1996, 35: 633-639. PMID: 8722812, DOI: 10.1002/mrm.1910350502.Peer-Reviewed Original ResearchConceptsSubacute stroke patientsProton magnetic resonance spectroscopicProton magnetic resonance spectroscopic imagingMagnetic resonance spectroscopic imagingStroke patientsHealthy subjectsMagnetic resonance spectroscopicMetabolite signal intensitiesBrain regionsPathological conditionsMacromolecule resonancesHuman brainBrainSignal intensitySubjectsRecovery timeSpectroscopic imagingPatientsHuman brain GABA levels rise after initiation of vigabatrin therapy but fail to rise further with increasing dose
Petroff O, Rothman D, Behar K, Mattson R. Human brain GABA levels rise after initiation of vigabatrin therapy but fail to rise further with increasing dose. Neurology 1996, 46: 1459-1463. PMID: 8628502, DOI: 10.1212/wnl.46.5.1459.Peer-Reviewed Original Research
1995
Initial Observations on Effect of Vigabatrin on In Vivo 1H Spectroscopic Measurements of γ‐Aminobutyric Acid, Glutamate, and Glutamine in Human Brain
Petroff O, Rothman D, Behar K, Mattson R. Initial Observations on Effect of Vigabatrin on In Vivo 1H Spectroscopic Measurements of γ‐Aminobutyric Acid, Glutamate, and Glutamine in Human Brain. Epilepsia 1995, 36: 457-464. PMID: 7614922, DOI: 10.1111/j.1528-1157.1995.tb00486.x.Peer-Reviewed Original ResearchConceptsGamma-aminobutyric acidGABA levelsMumol/Antiepileptic drugsOccipital GABA levelsEffective antiepileptic drugEffects of vigabatrinStandard medicationStandard doseΓ-aminobutyric acidHealthy subjectsEpileptic patientsVigabatrinPatientsGABA transaminaseHuman cerebrumNoninvasive measurementHuman brainBrainGlutamateInitial observationsMedicationsCerebrumLevelsDoseSimultaneous Determination of the Rates of the TCA Cycle, Glucose Utilization, α-Ketoglutarate/Glutamate Exchange, and Glutamine Synthesis in Human Brain by NMR
Mason G, Gruetter R, Rothman D, Behar K, Shulman R, Novotny E. Simultaneous Determination of the Rates of the TCA Cycle, Glucose Utilization, α-Ketoglutarate/Glutamate Exchange, and Glutamine Synthesis in Human Brain by NMR. Cerebrovascular And Brain Metabolism Reviews 1995, 15: 12-25. PMID: 7798329, DOI: 10.1038/jcbfm.1995.2.Peer-Reviewed Original ResearchVigabatrin: effect on brain GABA levels measured by nuclear magnetic resonance spectroscopy
Mattson R, Petroff O, Rothman D, Behar K. Vigabatrin: effect on brain GABA levels measured by nuclear magnetic resonance spectroscopy. Acta Neurologica Scandinavica. Supplementum 1995, 92: 27-30. PMID: 7495186, DOI: 10.1111/j.1600-0404.1995.tb00496.x.Peer-Reviewed Reviews, Practice Guidelines, Standards, and Consensus StatementsConceptsBrain GABA levelsGABA levelsBrain concentrationsNerve terminalsAdministration of vigabatrinClear dose-response relationshipLevels of GABAPartial epileptic seizuresAnti-epilepsy drugsPresynaptic nerve terminalsDose-response relationshipConcentration of GABASecondary generalizationClinical effectsClinical outcomesVigabatrin administrationClinical trialsPatient responseClinical studiesSynaptic transmissionBaseline valuesOptimal doseVigabatrin levelsVigabatrinEpileptic seizures
1994
Dynamic Magnetic Resonance Imaging of the Rat Brain during Forepaw Stimulation
Hyder F, Behar K, Martin M, Blamire A, Shulman R. Dynamic Magnetic Resonance Imaging of the Rat Brain during Forepaw Stimulation. Cerebrovascular And Brain Metabolism Reviews 1994, 14: 649-655. PMID: 8014212, DOI: 10.1038/jcbfm.1994.81.Peer-Reviewed Original ResearchConceptsSomatosensory areaChloralose-anesthetized ratsDynamic magnetic resonance imagingMagnetic resonance imagingForelimb motorForepaw stimulationRat brainBrain mapping methodsElectrical stimulationMR signal intensityParietal cortexResonance imagingBrain tissueCoronal planeFractional signal changeStimulationSignal changesOxygenation stateSignal intensityRatsAnteriorCortexBloodBrainMeasurement of GABA following GABA‐transaminase inhibition by gabaculine: A 1H and 31P NMR spectroscopic study of rat brain in vivo
Behar K, Boehm D. Measurement of GABA following GABA‐transaminase inhibition by gabaculine: A 1H and 31P NMR spectroscopic study of rat brain in vivo. Magnetic Resonance In Medicine 1994, 31: 660-667. PMID: 7914662, DOI: 10.1002/mrm.1910310612.Peer-Reviewed Original ResearchMeSH Keywords4-Aminobutyrate TransaminaseAnimalsAspartic AcidBrainBrain ChemistryCreatineCyclohexanecarboxylic AcidsGamma-Aminobutyric AcidGlutamatesGlutamic AcidHydrogenHydrogen-Ion ConcentrationMagnetic Resonance SpectroscopyMaleNucleotidesPhosphatesPhosphocreatinePhosphorusRatsRats, Sprague-Dawley