2021
Small loci of astroglial glutamine synthetase deficiency in the postnatal brain cause epileptic seizures and impaired functional connectivity
Farina MG, Sandhu MRS, Parent M, Sanganahalli BG, Derbin M, Dhaher R, Wang H, Zaveri HP, Zhou Y, Danbolt NC, Hyder F, Eid T. Small loci of astroglial glutamine synthetase deficiency in the postnatal brain cause epileptic seizures and impaired functional connectivity. Epilepsia 2021, 62: 2858-2870. PMID: 34536233, PMCID: PMC9006438, DOI: 10.1111/epi.17072.Peer-Reviewed Original ResearchConceptsPostnatal brainFunctional connectivityContinuous video-electroencephalographic recordingSpontaneous recurrent seizuresPathogenesis of epilepsyGlutamine synthetase deficiencyVideo-electroencephalographic recordingsSpecific animal modelsEx vivo studySeizure thresholdAdult patientsRecurrent seizuresFocal epilepsyAdeno-associated virusHippocampal formationAnimal modelsFocal mannerEpileptic seizuresGS deficiencySmall lociSynthetase deficiencyEpilepsyGradual returnVivo studiesBrainNetwork-Related Changes in Neurotransmitters and Seizure Propagation During Rodent Epileptogenesis
Dhaher R, Gruenbaum SE, Sandhu MRS, Ottestad-Hansen S, Tu N, Wang Y, Lee TW, Deshpande K, Spencer DD, Danbolt NC, Zaveri HP, Eid T. Network-Related Changes in Neurotransmitters and Seizure Propagation During Rodent Epileptogenesis. Neurology 2021, 96: e2261-e2271. PMID: 33722994, PMCID: PMC8166437, DOI: 10.1212/wnl.0000000000011846.Peer-Reviewed Original ResearchConceptsSpontaneous seizuresSeizure propagationSeizure focusMesial temporal lobe epilepsyExtracellular brain levelsTemporal lobe epilepsyExtracellular glutamate levelsRelevant rodent modelsGlutamine synthetase inhibitor methionine sulfoximineTransporter subtype 1Contralateral hippocampusLobe epilepsyBrain levelsBrain microdialysisExtracellular GABANeurotransmitter levelsSeizure initiationGlutamate levelsSeizure onsetEpilepsy networkRodent modelsSubtype 1EpileptogenesisHippocampusBrain regionsAltered hippocampal astroglial metabolism is associated with aging and preserved spatial learning and memory
Ebersole J, Rose G, Eid T, Behar K, Patrylo P. Altered hippocampal astroglial metabolism is associated with aging and preserved spatial learning and memory. Neurobiology Of Aging 2021, 102: 188-199. PMID: 33774381, DOI: 10.1016/j.neurobiolaging.2021.02.015.Peer-Reviewed Original ResearchConceptsArtificial cerebrospinal fluidAstroglial metabolismNeural metabolismHippocampus-dependent cognitive functionGlutamate-glutamine cyclingFischer 344 ratsHippocampus-dependent learningAge-related decreaseAU ratsCognitive functionLiquid chromatography-tandem mass spectroscopyGlutamatergic neurotransmissionCognitive declineHippocampal slicesSpatial learningCognitive statusHippocampal subregionsCerebrospinal fluidImpaired ratsMetabolism correlateYoung adultsCompensatory changesRatsC-glucoseMemory
2020
Gene expression in the epileptic (EL) mouse hippocampus
Lee TS, Li AY, Rapuano A, Mantis J, Eid T, Seyfried TN, de Lanerolle NC. Gene expression in the epileptic (EL) mouse hippocampus. Neurobiology Of Disease 2020, 147: 105152. PMID: 33153970, DOI: 10.1016/j.nbd.2020.105152.Peer-Reviewed Original ResearchConceptsTemporal lobe epilepsyHuman temporal lobe epilepsySeizure focusHippocampal seizure focusRole of neurogliaExtensive neuronal lossMolecular changesEpileptic miceMicroglial activationNeuronal lossNeuron lossEl miceLobe epilepsySeizure modelHippocampal fieldsSeizure generationPathological changesPaucity of studiesMouse hippocampusAnimal modelsHeat shock proteinsNormal populationPathological processesExpression levelsEpilepsyNovel aspects of glutamine synthetase in ammonia homeostasis
Zhou Y, Eid T, Hassel B, Danbolt NC. Novel aspects of glutamine synthetase in ammonia homeostasis. Neurochemistry International 2020, 140: 104809. PMID: 32758585, DOI: 10.1016/j.neuint.2020.104809.Peer-Reviewed Original ResearchConceptsGamma-aminobutyric acidSevere liver diseaseElevated blood ammoniaAmmonia homeostasisInhibitory neurotransmitters glutamateUrea cycleEffects of hyperammonemiaPotassium bufferingNeurological sequelaeBrain edemaLiver diseaseBrain pathophysiologyUrea cycle pathwayBlood ammoniaExtrahepatic tissuesNeurotransmitter glutamateAmmonia clearanceAminobutyric acidComplete urea cycleCycle pathwayTwo-thirdsGlutamine synthetaseRecent studiesHomeostasisBody ammonia
2018
Astrocytes and Glutamine Synthetase in Epileptogenesis
Eid T, Lee T, Patrylo P, Zaveri HP. Astrocytes and Glutamine Synthetase in Epileptogenesis. Journal Of Neuroscience Research 2018, 97: 1345-1362. PMID: 30022509, PMCID: PMC6338538, DOI: 10.1002/jnr.24267.Peer-Reviewed Original ResearchConceptsMesial temporal lobe epilepsyTemporal lobe epilepsyLobe epilepsyAstrocytic glutamine synthetaseRole of astrocytesPotassium channel Kir4.1Important causative factorExcitatory amino acid transporters EAAT1Antiepileptogenic interventionsEpileptogenic insultAntiepileptogenic therapiesEpilepsy developmentChannel Kir4.1Aquaporin-4EpilepsyCausative factorsTransporters EAAT1New targetsSuch interventionsTransporters MCT1DysfunctionAstrocytesMetabolic mechanismsGlutamine synthetaseDownstream effects
2008
Recurrent seizures and brain pathology after inhibition of glutamine synthetase in the hippocampus in rats
Eid T, Ghosh A, Wang Y, Beckström H, Zaveri HP, Lee TS, Lai JC, Malthankar-Phatak GH, de Lanerolle NC. Recurrent seizures and brain pathology after inhibition of glutamine synthetase in the hippocampus in rats. Brain 2008, 131: 2061-2070. PMID: 18669513, PMCID: PMC2724901, DOI: 10.1093/brain/awn133.Peer-Reviewed Original ResearchConceptsMesial temporal lobe epilepsyMesial temporal sclerosisRecurrent seizuresTemporal sclerosisBrain pathologyIntractable mesial temporal lobe epilepsyTemporal lobe epilepsyGlutamine synthetase deficiencyNovel animal modelContinuous microinfusionHippocampal atrophyLobe epilepsyGlutamate excessNeuropathological featuresExtracellular glutamateHippocampal neuronsAnimal modelsTherapeutic interventionsHippocampusSeizuresSclerosisSynthetase deficiencyMinimal injuryPatientsRats
2001
Disruption of Inhibition in Area CA1 of the Hippocampus in a Rat Model of Temporal Lobe Epilepsy
Denslow M, Eid T, Du F, Schwarcz R, Lothman E, Steward O. Disruption of Inhibition in Area CA1 of the Hippocampus in a Rat Model of Temporal Lobe Epilepsy. Journal Of Neurophysiology 2001, 86: 2231-2245. PMID: 11698514, DOI: 10.1152/jn.2001.86.5.2231.Peer-Reviewed Original ResearchConceptsTemporal lobe epilepsyLayer III neuronsPaired-pulse stimulationEntorhinal cortexCommissural projectionsDisruption of inhibitionHeterosynaptic inhibitionAOAA injectionPopulation spikesLobe epilepsyInhibitory functionDentate gyrusRat modelAminooxyacetic acidInhibitory interneuronsControl animalsElectrolytic lesionsTemporo-ammonic pathwayMultiple population spikesPaired-pulse inhibitionDuration of afterdischargeLoss of neuronsHigh-frequency stimulationNumber of stimulationsAbnormal physiological responsesIbotenate Injections into the Pre‐ and Parasubiculum Provide Partial Protection against Kainate‐Induced Epileptic Damage in Layer III of Rat Entorhinal Cortex
Eid T, Du F, Schwarcz R. Ibotenate Injections into the Pre‐ and Parasubiculum Provide Partial Protection against Kainate‐Induced Epileptic Damage in Layer III of Rat Entorhinal Cortex. Epilepsia 2001, 42: 817-824. PMID: 11488878, DOI: 10.1046/j.1528-1157.2001.042007817.x.Peer-Reviewed Original ResearchConceptsTemporal lobe epilepsyEntorhinal cortexLayer IIIIbotenate injectionLobe epilepsySeizure-induced damageLoss of neuronsLayer III neuronsRat entorhinal cortexEpileptic damagePartial neuroprotectionExcitatory afferentsPrimary lesionSeizure activityEntorhinal neuronsAnimal modelsIbotenate lesionsPartial protectionLesionsNeuronsKainatePresubiculumEpilepsySerial reconstructionCortex
2000
Neurons in Layer III of the Entorhinal Cortex: A Role in Epileptogenesis and Epilepsy?
SCHWARCZ R, EID T, DU F. Neurons in Layer III of the Entorhinal Cortex: A Role in Epileptogenesis and Epilepsy? Annals Of The New York Academy Of Sciences 2000, 911: 328-342. PMID: 10911883, DOI: 10.1111/j.1749-6632.2000.tb06735.x.Peer-Reviewed Original ResearchConceptsTemporal lobe epilepsyEntorhinal cortexLayer IIILobe epilepsySeizure-induced cell deathProminent excitatory inputSeizure-induced deathLayer III neuronsAminooxyacetic acidAOAA injectionPreferential lesionGABAergic neuronsNeuron lossLimbic structuresExcitatory inputsPathological changesParahippocampal structuresAnimal modelsEpilepsyNeuronsLesionsCell deathCortexDeathInjection
1999
Ultrastructure and immunocytochemical distribution of GABA in layer III of the rat medial entorhinal cortex following aminooxyacetic acid-induced seizures
Eid T, Schwarcz R, Ottersen OP. Ultrastructure and immunocytochemical distribution of GABA in layer III of the rat medial entorhinal cortex following aminooxyacetic acid-induced seizures. Experimental Brain Research 1999, 125: 463-475. PMID: 10323293, DOI: 10.1007/s002210050704.Peer-Reviewed Original ResearchConceptsTemporal lobe epilepsyEntorhinal cortexLayer IIIMedial entorhinal cortexAminooxyacetic acidGABA-immunoreactive neuronsTemporal lobe seizuresAcid-induced seizuresGABA-like immunoreactivityDifferent animal modelsHippocampal region CA1AOAA injectionSimilar neuropathologySwollen dendritesBehavioral seizuresGABA neuronsLobe epilepsyNeuronal profilesNeuropathological changesPyramidal neuronsNerve terminalsAxon terminalsRat medialDendritic spinesLight microscopic preparations
1997
Neuronal damage after the injection of amino-oxyacetic acid into the rat entorhinal cortex: a silver impregnation study
Du F, Eid T, Schwarcz R. Neuronal damage after the injection of amino-oxyacetic acid into the rat entorhinal cortex: a silver impregnation study. Neuroscience 1997, 82: 1165-1178. PMID: 9466438, DOI: 10.1016/s0306-4522(97)00354-0.Peer-Reviewed Original ResearchConceptsSilver-stained neuronsTemporal lobe epilepsyEntorhinal cortexAcid injectionNeuronal damageLobe epilepsyLayer IIIProlonged seizure activitySilver impregnation studyReactive glial cellsPattern of neurodegenerationHippocampal CA1 fieldLateral amygdaloid nucleusRat entorhinal cortexAminooxyacetic acidAmino-oxyacetic acidMedial entorhinal cortexDegenerated neuronsNeuropathological consequencesDamaged neuronsSeizure activityAmygdaloid nucleusMost neuronsNeuronal deathCA1 fieldSleep/waking effects of a selective 5-HT1A receptor agonist given systemically as well as perfused in the dorsal raphe nucleus in rats
Bjorvatn B, Fagerland S, Eid T, Ursin R. Sleep/waking effects of a selective 5-HT1A receptor agonist given systemically as well as perfused in the dorsal raphe nucleus in rats. Brain Research 1997, 770: 81-88. PMID: 9372206, DOI: 10.1016/s0006-8993(97)00758-0.Peer-Reviewed Original ResearchConceptsDorsal raphe nucleusSlow-wave sleepRaphe nucleusSleep/Rapid eye movement (REM) sleepREM sleep increaseDeep slow wave sleepEye movement sleepArtificial cerebrospinal fluidMesopontine neuronsAutoreceptor stimulationReceptor agonistMovement sleepREM sleepCerebrospinal fluidWave sleepSleep increasesDPATPerfusionSleepAgonistsFourfold increaseBehavioral syndromeSyndromeNeurotransmission
1996
Afferents to the seizure-sensitive neurons in layer III of the medial entorhinal area: a tracing study in the rat
Eid T, Jorritsma-Byham B, Schwarcz R, Witter MP. Afferents to the seizure-sensitive neurons in layer III of the medial entorhinal area: a tracing study in the rat. Experimental Brain Research 1996, 109: 209-218. PMID: 8738371, DOI: 10.1007/bf00231782.Peer-Reviewed Original ResearchConceptsMedial entorhinal areaEntorhinal areaLayer IIIThalamic nucleiIontophoretic injectionVentral portionSeptum-diagonal band complexRetrograde tracer Fast BlueAnteroventral thalamic nucleusTemporal lobe epilepsyAnterograde tracing techniquesAnteromedial thalamic nucleusNucleus raphe dorsalisTracer Fast BlueLateral entorhinal areaAmino-oxyacetic acidLimbic seizuresLobe epilepsyNeuronal vulnerabilityVentrolateral hypothalamusSurgical specimensAnterograde tracerLayer IVRaphe dorsalisFast Blue
1995
Preferential neuronal loss in layer III of the medial entorhinal cortex in rat models of temporal lobe epilepsy
Du F, Eid T, Lothman E, Kohler C, Schwarcz R. Preferential neuronal loss in layer III of the medial entorhinal cortex in rat models of temporal lobe epilepsy. Journal Of Neuroscience 1995, 15: 6301-6313. PMID: 7472396, PMCID: PMC6577998, DOI: 10.1523/jneurosci.15-10-06301.1995.Peer-Reviewed Original ResearchConceptsPreferential neuronal lossTemporal lobe epilepsyNeuronal lossMedial entorhinal cortexEntorhinal cortexLayer IIILobe epilepsyRat modelIntractable temporal lobe epilepsyAcute status epilepticusLithium/pilocarpineParvalbumin-positive neuronsIntracellular calcium ion concentrationKainic acid administrationNerve cell lossAdult male ratsInjection of diazepamSurviving neuronsProlonged seizuresStatus epilepticusAcid administrationNissl stainingVentral hippocampusKainic acidPathological elevationDifferential neuronal vulnerability to amino-oxyacetate and quinolinate in the rat parahippocampal region
Eid T, Du F, Schwarcz R. Differential neuronal vulnerability to amino-oxyacetate and quinolinate in the rat parahippocampal region. Neuroscience 1995, 68: 645-656. PMID: 8577365, DOI: 10.1016/0306-4522(95)00183-j.Peer-Reviewed Original ResearchConceptsAcute behavioral seizuresBehavioral seizuresDizocilpine maleateNeuronal lossEntorhinal cortexEndogenous N-methyl-D-aspartate receptor agonistN-methyl-D-aspartate receptor antagonist dizocilpine maleateLayer IIIN-methyl-D-aspartate receptor agonistParahippocampal regionN-methyl-D-aspartate (NMDA) receptor subtypeDifferential neuronal vulnerabilityDorsal perirhinal cortexPreferential neuronal lossTemporal lobe epilepsyChloral hydrate anesthesiaLower anesthetic doseNeuropathological sequelaeLobe epilepsyNeuropathological changesLayer VNeuronal vulnerabilityPreferential degenerationAnesthetic doseReceptor agonist
1993
The Use of Hydrophobic Adhesive Tape to Produce Miniature Wells on Microscope Slides
Eid T. The Use of Hydrophobic Adhesive Tape to Produce Miniature Wells on Microscope Slides. Biotechnic & Histochemistry 1993, 68: 189-192. PMID: 8218571, DOI: 10.3109/10520299309104696.Peer-Reviewed Original Research