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 functionsDeficiencyNeural control of fluid homeostasis is engaged below 10°C in hibernation
Junkins M, Feng N, Murphy L, Curtis G, Merriman D, Bagriantsev S, Gracheva E. Neural control of fluid homeostasis is engaged below 10°C in hibernation. Current Biology 2024, 34: 923-930.e5. PMID: 38325375, PMCID: PMC11232715, DOI: 10.1016/j.cub.2024.01.035.Peer-Reviewed Original ResearchConceptsAntidiuretic hormone arginine vasopressinSupraoptic nucleusFluid homeostasisC-Fos immunohistochemistryControl of fluid homeostasisHeart rateHypothalamic supraoptic nucleusReduced plasma levelsHormone arginine vasopressinPlasma hormone levelsSlow heart rateSON neuronsArginine vasopressinMassive fluid lossPlasma levelsPosterior pituitaryHormone levelsFiber photometryC-fosBlood pressureNeuronal activityHormonal responsesThirteen-lined ground squirrelsOxytocinInterbout arousal
2023
Ground squirrels – experts in thermoregulatory adaptation
Feketa V, Bagriantsev S, Gracheva E. Ground squirrels – experts in thermoregulatory adaptation. Trends In Neurosciences 2023, 46: 505-507. PMID: 37188617, DOI: 10.1016/j.tins.2023.04.008.Peer-Reviewed Reviews, Practice Guidelines, Standards, and Consensus Statements
2020
CNGA3 acts as a cold sensor in hypothalamic neurons
Feketa VV, Nikolaev YA, Merriman DK, Bagriantsev SN, Gracheva EO. CNGA3 acts as a cold sensor in hypothalamic neurons. ELife 2020, 9: e55370. PMID: 32270761, PMCID: PMC7182431, DOI: 10.7554/elife.55370.Peer-Reviewed Original Research
2019
Osmolyte Depletion and Thirst Suppression Allow Hibernators to Survive for Months without Water
Feng NY, Junkins MS, Merriman DK, Bagriantsev SN, Gracheva EO. Osmolyte Depletion and Thirst Suppression Allow Hibernators to Survive for Months without Water. Current Biology 2019, 29: 3053-3058.e3. PMID: 31495581, PMCID: PMC6759396, DOI: 10.1016/j.cub.2019.07.038.Peer-Reviewed Original Research
2018
Somatosensory Neurons Enter a State of Altered Excitability during Hibernation
Hoffstaetter LJ, Mastrotto M, Merriman DK, Dib-Hajj SD, Waxman SG, Bagriantsev SN, Gracheva EO. Somatosensory Neurons Enter a State of Altered Excitability during Hibernation. Current Biology 2018, 28: 2998-3004.e3. PMID: 30174191, PMCID: PMC6173314, DOI: 10.1016/j.cub.2018.07.020.Peer-Reviewed Original ResearchConceptsSomatosensory neuronsAction potentialsPeripheral somatosensory neuronsVoltage-gated sodium channelsTherapeutic hypothermiaAltered excitabilityFunctional deficitsCase of neuronsSensory functionFiring patternsNeuronsCold exposureInput resistanceSodium channelsRapid restorationBody temperatureHypometabolismHypothermiaDevelopment of strategiesSensory informationProlonged periodAdaptive responseArousalCNSExcitability
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