2007
Altered cerebral glucose and acetate metabolism in succinic semialdehyde dehydrogenase‐deficient mice: evidence for glial dysfunction and reduced glutamate/glutamine cycling
Chowdhury GM, Gupta M, Gibson KM, Patel AB, Behar KL. Altered cerebral glucose and acetate metabolism in succinic semialdehyde dehydrogenase‐deficient mice: evidence for glial dysfunction and reduced glutamate/glutamine cycling. Journal Of Neurochemistry 2007, 103: 2077-2091. PMID: 17854388, DOI: 10.1111/j.1471-4159.2007.04887.x.Peer-Reviewed Original ResearchMeSH KeywordsAcetatesAmino AcidsAnimalsAnimals, NewbornBlood GlucoseCarbon IsotopesCerebral CortexGamma-Aminobutyric AcidGlutamate-Ammonia LigaseGlutamic AcidGlutamineImage Processing, Computer-AssistedMagnetic Resonance SpectroscopyMiceMice, KnockoutNeurogliaSodium OxybateSuccinate-Semialdehyde DehydrogenaseTime FactorsConceptsSSADH deficiencyLevels of GABAGlutamate/glutamine cyclingSuccinic semialdehyde dehydrogenase‐deficient miceGlutamine-C4Cerebral metabolismCerebral glucoseCortical extractsGlial dysfunctionIntraperitoneal infusionSuccinic semialdehyde dehydrogenaseGABA-C2Excessive elevationNeurotransmitter glutamateGABA synthesisGABAMiceGHBGlutamateGlutamine metabolismAspartate C3GliaCortexGlutamine cyclingGlial substrate
2001
Glutamine is the major precursor for GABA synthesis in rat neocortex in vivo following acute GABA-transaminase inhibition
Patel A, Rothman D, Cline G, Behar K. Glutamine is the major precursor for GABA synthesis in rat neocortex in vivo following acute GABA-transaminase inhibition. Brain Research 2001, 919: 207-220. PMID: 11701133, DOI: 10.1016/s0006-8993(01)03015-3.Peer-Reviewed Original ResearchIn Vivo Nuclear Magnetic Resonance Studies of Glutamate-γ-Aminobutyric Acid-Glutamine Cycling in Rodent and Human Cortex: the Central Role of Glutamine
Behar K, Rothman D. In Vivo Nuclear Magnetic Resonance Studies of Glutamate-γ-Aminobutyric Acid-Glutamine Cycling in Rodent and Human Cortex: the Central Role of Glutamine. Journal Of Nutrition 2001, 131: 2498s-2504s. PMID: 11533301, DOI: 10.1093/jn/131.9.2498s.Peer-Reviewed Reviews, Practice Guidelines, Standards, and Consensus StatementsConceptsGamma-aminobutyric acidGlutamate-GABACortical glucose utilizationCortical electrical activityNet glutamine synthesisCerebral cortexInhibitory neurotransmitterMajor excitatoryBrain glutamateGlutamine synthesisNeurotransmitter glutamateRodent cortexGlucose utilizationHuman cortexGlutamine cycleElectrical activityCortexCentral roleGlutamine cyclingCommon mechanismGlucose oxidationGlutamateVivo nuclear magnetic resonance studiesRodentsGlutamineDecrease in GABA synthesis rate in rat cortex following GABA-transaminase inhibition correlates with the decrease in GAD67 protein
Mason G, Martin D, Martin S, Manor D, Sibson N, Patel A, Rothman D, Behar K. Decrease in GABA synthesis rate in rat cortex following GABA-transaminase inhibition correlates with the decrease in GAD67 protein. Brain Research 2001, 914: 81-91. PMID: 11578600, DOI: 10.1016/s0006-8993(01)02778-0.Peer-Reviewed Original ResearchConceptsTotal GAD activityGAD activityNon-treated control groupGABA-transaminase inhibitionNitrous oxide anesthesiaCortex of controlGlutamate-glutamine cyclingGlutamic acid decarboxylaseGABA synthesis rateGamma-aminobutyric acid (GABA) synthesisVigabatrin treatmentOxide anesthesiaRat cortexGAD67 proteinControl groupBasal conditionsAcid decarboxylaseEx vivoNeuronal compartmentsVigabatrinQuantitative immunoblottingIsoform compositionRatsCortexInhibitionIn 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
1999
In vivo nuclear magnetic resonance spectroscopy studies of the relationship between the glutamate--glutamine neurotransmitter cycle and functional neuroenergetics
Rothman D, Sibson N, Hyder F, Shen J, Behar K, Shulman R. In vivo nuclear magnetic resonance spectroscopy studies of the relationship between the glutamate--glutamine neurotransmitter cycle and functional neuroenergetics. Philosophical Transactions Of The Royal Society B Biological Sciences 1999, 354: 1165-1177. PMID: 10466144, PMCID: PMC1692640, DOI: 10.1098/rstb.1999.0472.Peer-Reviewed Reviews, Practice Guidelines, Standards, and Consensus StatementsConceptsGlutamate-glutamine cycleNerve terminalsNeurotransmitter cycleGlucose metabolismBlood oxygenation level-dependent magnetic resonance imagingLevel-dependent magnetic resonance imagingBrain glucose oxidationCortical glucose metabolismMagnetic resonance spectroscopy studyCortex of ratsMagnetic resonance imagingFunctional imaging studiesSpecific neuronal activityOxidative glucose metabolismGlial cellsNeuronal activityResonance imagingImaging studiesHuman cortexBrain functionBrain activityRatsCortexGlucose oxidationGlutamateDetermination of the rate of the glutamate/glutamine cycle in the human brain by in vivo 13C NMR
Shen J, Petersen K, Behar K, Brown P, Nixon T, Mason G, Petroff O, Shulman G, Shulman R, Rothman D. Determination of the rate of the glutamate/glutamine cycle in the human brain by in vivo 13C NMR. Proceedings Of The National Academy Of Sciences Of The United States Of America 1999, 96: 8235-8240. PMID: 10393978, PMCID: PMC22218, DOI: 10.1073/pnas.96.14.8235.Peer-Reviewed Original ResearchConceptsGlutamate/glutamine cycleGlutamine cycleCerebral cortexMin/Rat cerebral cortexVivo 13C NMR spectraGlucose oxidation ratesHuman brainGlucose oxidationGlutamatergic activityRat modelTricarboxylic acid cycle rateParietal lobeHuman cortexCortexTime courseBrainGlutamine synthesisMajor metabolic fluxCycle rateTricarboxylic acid cycleHigh levelsInfusionRatsAcid cycle
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
In 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
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 Research
1994
Analysis of macromolecule resonances in 1H NMR spectra of human brain
Behar K, Rothman D, Spencer D, Petroff O. Analysis of macromolecule resonances in 1H NMR spectra of human brain. Magnetic Resonance In Medicine 1994, 32: 294-302. PMID: 7984061, DOI: 10.1002/mrm.1910320304.Peer-Reviewed Original Research
1991
Assignment of resonances in the 1H spectrum of rat brain by two‐dimensional shift correlated and j‐resolved NMR spectroscopy
Behar K, Ogino T. Assignment of resonances in the 1H spectrum of rat brain by two‐dimensional shift correlated and j‐resolved NMR spectroscopy. Magnetic Resonance In Medicine 1991, 17: 285-303. PMID: 1676483, DOI: 10.1002/mrm.1910170202.Peer-Reviewed Original Research
1989
Effects of Acute Hyperammonemia on Cerebral Amino Acid Metabolism and pHi In Vivo, Measured by 1H and 31P Nuclear Magnetic Resonance
Fitzpatrick S, Hetherington H, Behar K, Shulman R. Effects of Acute Hyperammonemia on Cerebral Amino Acid Metabolism and pHi In Vivo, Measured by 1H and 31P Nuclear Magnetic Resonance. Journal Of Neurochemistry 1989, 52: 741-749. PMID: 2563756, DOI: 10.1111/j.1471-4159.1989.tb02517.x.Peer-Reviewed Original ResearchConceptsAmmonia infusionCerebral amino acid metabolismCerebral glutamate levelsAcute intravenous infusionBrain glutamate concentrationsBrain lactate levelsMin of infusionContent of phosphocreatineBrain lactate contentGlutamine concentrationPreinfusion controlAcute hyperammonemiaIntravenous infusionCerebral glutamateControl infusionGlutamate levelsInfusion protocolArterial PCO2Lactate levelsPreinfusion valuesBrain glutamineBlood ammoniaMagnetic resonanceInfusionGlutamate concentration
1986
Detection of metabolites in rabbit brain by 13C NMR spectroscopy following administration of [1‐13C]glucose
Behar K, Petroff O, Prichard J, Alger J, Shulman R. Detection of metabolites in rabbit brain by 13C NMR spectroscopy following administration of [1‐13C]glucose. Magnetic Resonance In Medicine 1986, 3: 911-920. PMID: 2881185, DOI: 10.1002/mrm.1910030611.Peer-Reviewed Original Research
1985
Effect of Hypoglycemic Encephalopathy upon Amino Acids, High‐Energy Phosphates, and pHi in the Rat Brain In Vivo: Detection by Sequential 1H and 31P NMR Spectroscopy
Behar K, Hollander J, Petroff O, Hetherington H, Prichard J, Shulman R. Effect of Hypoglycemic Encephalopathy upon Amino Acids, High‐Energy Phosphates, and pHi in the Rat Brain In Vivo: Detection by Sequential 1H and 31P NMR Spectroscopy. Journal Of Neurochemistry 1985, 44: 1045-1055. PMID: 2857770, DOI: 10.1111/j.1471-4159.1985.tb08723.x.Peer-Reviewed Original Research