Shaun James, PhD
Visiting Research ScientistCards
About
Research
Publications
2023
Spatiotemporal features of neurovascular (un)coupling with stimulus-induced activity and hypercapnia challenge in cerebral cortex and olfactory bulb
James S, Sanggaard S, Akif A, Mishra S, Sanganahalli B, Blumenfeld H, Verhagen J, Hyder F, Herman P. Spatiotemporal features of neurovascular (un)coupling with stimulus-induced activity and hypercapnia challenge in cerebral cortex and olfactory bulb. Cerebrovascular And Brain Metabolism Reviews 2023, 43: 1891-1904. PMID: 37340791, PMCID: PMC10676132, DOI: 10.1177/0271678x231183887.Peer-Reviewed Original ResearchConceptsVasodilatory responseCerebral cortexNeurovascular couplingOlfactory bulbNeuronal activityBrief sensory stimuliRegional neurovascular couplingStimulus-induced activityHypercapnia challengeVascular toneNeuronal deactivationHemodynamic responseNeuronal excitabilityNeuronal responsesCalcium transientsBrain functionHemodynamic signalsSensory stimuliVasodilationHypercapniaCortexMiceCareful appraisalStimuliMetabolic waste
2021
Disordered breathing in a Pitt-Hopkins syndrome model involves Phox2b-expressing parafacial neurons and aberrant Nav1.8 expression
Cleary C, James S, Maher B, Mulkey D. Disordered breathing in a Pitt-Hopkins syndrome model involves Phox2b-expressing parafacial neurons and aberrant Nav1.8 expression. Nature Communications 2021, 12: 5962. PMID: 34645823, PMCID: PMC8514575, DOI: 10.1038/s41467-021-26263-2.Peer-Reviewed Original ResearchMeSH KeywordsAnimalsBasic Helix-Loop-Helix Transcription FactorsBenzimidazolesBrain StemCarbon DioxideDisease Models, AnimalFaciesGene Expression RegulationHaploinsufficiencyHomeodomain ProteinsHumansHyperventilationIntellectual DisabilityMaleMiceMice, KnockoutNAV1.8 Voltage-Gated Sodium ChannelNeuronsPsychomotor PerformancePyrazolesRespirationTranscription Factor 4Transcription FactorsConceptsPitt-Hopkins syndromeParafacial neuronsBreathing problemsEpisodes of hyperventilationFunction of neuronsNav1.8 expressionPTH patientsRetrotrapezoid nucleusNav1.8 channelsTranscription factor 4Behavioral deficitsMouse modelRespiratory functionBehavioral abnormalitiesTherapeutic potentialSyndrome modelDevelopmental delaySelective lossNeuronsIntellectual disabilityFactor 4Functional haploinsufficiencyBehavioral levelNav1.8ApneaSelective Overexpression of Collybistin in Mouse Hippocampal Pyramidal Cells Enhances GABAergic Neurotransmission and Protects against PTZ-Induced Seizures
George S, James S, De Blas A. Selective Overexpression of Collybistin in Mouse Hippocampal Pyramidal Cells Enhances GABAergic Neurotransmission and Protects against PTZ-Induced Seizures. ENeuro 2021, 8: eneuro.0561-20.2021. PMID: 34083383, PMCID: PMC8281261, DOI: 10.1523/eneuro.0561-20.2021.Peer-Reviewed Original ResearchConceptsHippocampal pyramidal cellsPyramidal cellsPyramidal neuronsAdeno-associated virusGABAergic synaptic transmissionCortical pyramidal neuronsHippocampal pyramidal neuronsMouse hippocampal pyramidal cellsCultured hippocampal neuronsAbsence of gephyrinCre-dependent mannerGABAergic neurotransmissionCre miceInhibitory neurotransmissionHippocampal interneuronsInhibitory postsynapsesInhibitory synapsesHippocampal neuronsSynaptic transmissionTarget neuronsPostsynaptic sitesBrain regionsMice resultsSelective overexpressionGlycinergic postsynapsesSomatostatin-expressing parafacial neurons are CO2/H+ sensitive and regulate baseline breathing
Cleary C, Milla B, Kuo F, James S, Flynn W, Robson P, Mulkey D. Somatostatin-expressing parafacial neurons are CO2/H+ sensitive and regulate baseline breathing. ELife 2021, 10: e60317. PMID: 34013884, PMCID: PMC8169115, DOI: 10.7554/elife.60317.Peer-Reviewed Original ResearchMeSH KeywordsAnimalsCarbon DioxideChemoreceptor CellsDisease Models, AnimalEpilepsies, MyoclonicFemaleGlutamic AcidHydrogenIntralaminar Thalamic NucleiLungMaleMice, 129 StrainMice, Inbred C57BLMice, TransgenicNAV1.1 Voltage-Gated Sodium ChannelNeural InhibitionRespirationSomatostatinSynaptic TransmissionConceptsParafacial neuronsRTN chemoreceptorsBaseline breathingParafacial regionInhibitory neuronsInhibitory synaptic interactionsInhibitory neural activityRTN chemoreceptionRTN neuronsChemogenetic suppressionDravet syndromeGlutamatergic neuronsInhibitory inputsMouse modelRespiratory chemoreceptorsSynaptic propertiesSynaptic interactionsTissue CONeuronsBreathingContext of diseaseNeural activityDependent mannerChemoreceptorsNucleus function
2018
Adenosine Signaling through A1 Receptors Inhibits Chemosensitive Neurons in the Retrotrapezoid Nucleus
James SD, Hawkins VE, Falquetto B, Ruskin DN, Masino SA, Moreira TS, Olsen ML, Mulkey DK. Adenosine Signaling through A1 Receptors Inhibits Chemosensitive Neurons in the Retrotrapezoid Nucleus. ENeuro 2018, 5: eneuro.0404-18.2018. PMID: 30627640, PMCID: PMC6325544, DOI: 10.1523/eneuro.0404-18.2018.Peer-Reviewed Original ResearchMeSH Keywords6-Cyano-7-nitroquinoxaline-2,3-dioneAdenosineAnimalsAnimals, NewbornBariumCarbon DioxideChemoreceptor CellsExcitatory Amino Acid AntagonistsFemaleMaleMice, Inbred C57BLMice, TransgenicNeuronal PlasticityNeurotransmitter AgentsPotassium Channel BlockersPurinergic AgentsRatsRats, Sprague-DawleyReceptors, Purinergic P1Respiratory CenterSignal TransductionSodium Channel BlockersTetrodotoxinConceptsChemosensitive RTN neuronsRTN neuronsA1 receptorsRTN chemoreceptorsChemoreceptor activitySelective A1 receptor antagonistFrequency of EPSCsWild-type mouse pupsA1 receptor antagonistExcitatory synaptic inputsReceptor-dependent mechanismEffects of adenosineSubset of neuronsCell-attached recordingsLike conductanceRTN chemoreceptionChemosensitive neuronsRetrotrapezoid nucleusReceptor antagonistSynaptic mechanismsMouse pupsSynaptic inputsRespiratory chemoreceptorsPurinergic signalingPurinergic regulationInfluence of Exogenous β-Hydroxybutyrate on Walking Economy and Rating of Perceived Exertion
James S, Greer B. Influence of Exogenous β-Hydroxybutyrate on Walking Economy and Rating of Perceived Exertion. Journal Of Dietary Supplements 2018, 16: 463-469. PMID: 29953297, DOI: 10.1080/19390211.2018.1471562.Peer-Reviewed Original ResearchConceptsRespiratory exchange ratioEnergy expenditureΒ-hydroxybutyrateExogenous β-hydroxybutyratePlacebo 30 minutesBruce treadmill protocolElevated postexerciseBlood BHB concentrationsBlood glucoseErgogenic benefitsBlood ketonesTreadmill protocolHealthy individualsCrossover designBaseline levelsTrial differencesExchange ratioCON conditionTime pointsPerceived ExertionBHB concentrationsGlucose concentrationOxygen consumptionExertionSupplementation