2024
Hypothalamic hormone deficiency enables physiological anorexia in ground squirrels during hibernation
Mohr S, Dai Pra R, Platt M, Feketa V, Shanabrough M, Varela L, Kristant A, Cao H, Merriman D, Horvath T, Bagriantsev S, Gracheva E. Hypothalamic hormone deficiency enables physiological anorexia in ground squirrels during hibernation. Nature Communications 2024, 15: 5803. PMID: 38987241, PMCID: PMC11236985, DOI: 10.1038/s41467-024-49996-2.Peer-Reviewed Original ResearchConceptsHypothalamic feeding centersHormone deficiencyHypothalamic arcuate nucleus neuronsArcuate nucleus neuronsThyroid hormone deficiencyFeeding centerEffects of ghrelinAnorexigenic effectNucleus neuronsPhysiological anorexiaThyroid hormonesNormal physiological functionsGround squirrelsInterbout arousalAnorexiaThirteen-lined ground squirrelsProlonged periodReduced sensitivityPhysiological functionsDeficiencyFrequency-modulated timer regulates torpor–arousal cycles during hibernation in distinct small mammalian hibernators
Gibo S, Yamaguchi Y, Gracheva E, Bagriantsev S, Tokuda I, Kurosawa G. Frequency-modulated timer regulates torpor–arousal cycles during hibernation in distinct small mammalian hibernators. Npj Biological Timing And Sleep 2024, 1: 3. DOI: 10.1038/s44323-024-00002-4.Peer-Reviewed Original ResearchTorpor-arousal cycleMolecular mechanisms of hibernationMammalian hibernationGround squirrelsHibernation patternsTb fluctuationsBiological processesHarsh seasonsHibernating speciesDeep torporMolecular mechanismsConstant laboratory conditionsSyrian hamstersHibernationTB dataEndogenous periodEuthermic levelsTorporPhysiological conditionsMechanisms of hibernationBasal metabolismAmbient levelsCircannual rhythmPeriods of arousalSquirrels
2017
Molecular Prerequisites for Diminished Cold Sensitivity in Ground Squirrels and Hamsters
Matos-Cruz V, Schneider ER, Mastrotto M, Merriman DK, Bagriantsev SN, Gracheva EO. Molecular Prerequisites for Diminished Cold Sensitivity in Ground Squirrels and Hamsters. Cell Reports 2017, 21: 3329-3337. PMID: 29262313, PMCID: PMC5741102, DOI: 10.1016/j.celrep.2017.11.083.Peer-Reviewed Original ResearchConceptsTransmembrane domainCold toleranceCold sensitivityGround squirrelsRat orthologMolecular adaptationsMammalian hibernatorsReciprocal mutationsAmino acidsFunctional significanceOrthologsSquirrelsMolecular prerequisitesActive stateHibernatorsTRPM8Somatosensory neuronsTolerancePoor activationSpeciesDomainMutationsResiduesHibernationCells
2016
Low-cost functional plasticity of TRPV1 supports heat tolerance in squirrels and camels
Laursen WJ, Schneider ER, Merriman DK, Bagriantsev SN, Gracheva EO. Low-cost functional plasticity of TRPV1 supports heat tolerance in squirrels and camels. Proceedings Of The National Academy Of Sciences Of The United States Of America 2016, 113: 11342-11347. PMID: 27638213, PMCID: PMC5056056, DOI: 10.1073/pnas.1604269113.Peer-Reviewed Original ResearchMeSH KeywordsAfferent PathwaysAmino Acid SequenceAmino Acid SubstitutionAnimalsAnkyrin RepeatCamelusCapsaicinConserved SequenceGanglia, SpinalHEK293 CellsHot TemperatureHumansHydrogen-Ion ConcentrationIon Channel GatingMutationNeuronsSciuridaeSequence AlignmentThermotoleranceTRPV Cation ChannelsXenopusConceptsHeat toleranceCommon molecular strategyN-terminal ankyrinSingle amino acid changeSingle amino acid substitutionGround squirrelsPolymodal ion channelAmino acid changesAmino acid substitutionsRemarkable functional flexibilityFunctional conservationEcological nichesChemical cuesMammalian speciesMolecular strategiesAcid changesAcid substitutionsHeat sensitivityTransient receptor potential vanilloid 1Ion channelsOrthologsFunctional plasticitySquirrelsBactrian camelsSuch adaptation
2015
Neuronal UCP1 expression suggests a mechanism for local thermogenesis during hibernation
Laursen WJ, Mastrotto M, Pesta D, Funk OH, Goodman JB, Merriman DK, Ingolia N, Shulman GI, Bagriantsev SN, Gracheva EO. Neuronal UCP1 expression suggests a mechanism for local thermogenesis during hibernation. Proceedings Of The National Academy Of Sciences Of The United States Of America 2015, 112: 1607-1612. PMID: 25605929, PMCID: PMC4321293, DOI: 10.1073/pnas.1421419112.Peer-Reviewed Original ResearchConceptsSummer active stateNervous tissue functionPalmitate-induced uncouplingDifferential transcriptomicsMolecular mechanismsHibernating mammalsBrown adipose tissueBody temperatureProtein 1Ground squirrelsBiochemical analysisTorpid squirrelsHibernation seasonTissue functionActive stateUCP1 expressionHigh expressionHibernationPharmacologic analysisThermogenic proteinsAdipose tissueBrain temperatureLow body temperatureNervous systemPhysiologic phenotype