Charles Greer, PhD
Cards
Appointments
Titles
Co Vice Chair of Research, Neurosurgery; Director, Interdepartmental Neuroscience Graduate Program
Contact Info
Appointments
Titles
Co Vice Chair of Research, Neurosurgery; Director, Interdepartmental Neuroscience Graduate Program
Contact Info
Appointments
Titles
Co Vice Chair of Research, Neurosurgery; Director, Interdepartmental Neuroscience Graduate Program
Contact Info
About
Titles
Professor of Neurosurgery and of Neuroscience
Co Vice Chair of Research, Neurosurgery; Director, Interdepartmental Neuroscience Graduate ProgramBiography
Dr. Charles A. Greer is the Vice Chair for Research and holds the rank of Professor of Neuroscience. Dr. Greer also serves as Director of the Yale Interdepartmental Neuroscience Graduate Program. He has served as the President of the Association for Chemoreception Sciences, Chair of National Institutes of Health Study Sections and recently completed a term on the Advisory Council for the National Institute of Deafness and Other Communicative Disorders.
He has organized several national and international conferences and is frequently an invited speaker. Dr. Greer is an Associate Editor of The Journal of Comparative Neurology and Journal of Neuroscience and a member of the editorial boards of Frontiers in Neurogenomics, Frontiers in Neuroanatomy and Frontiers in Neuorgenesis and the Faculty of 1000. Dr. Greer has been the recipient of numerous awards recognizing his research accomplishments.
Appointments
Neuroscience
ProfessorFully JointNeurosurgery
ProfessorFully Joint
Other Departments & Organizations
Education & Training
- PhD
- University of Colorado (1978)
- BA
- University of Colorado at Colorado Springs (1971)
- Postdoctoral Fellow
- Yale School of Medicine
Research
Overview
Current Research Program
A major goal of my laboratory is understanding the basic mechanisms that contribute to the establishment of orderly topographic maps within the CNS, during both normal development and during regenerative events following injury or disease. We have been focusing our efforts on the olfactory system, in part because of the complexity of the map between the olfactory epithelium and the olfactory bulb. Axons sort into 1,000 functional subsets that are targeted with high specificity to olfactory bulb glomeruli.
Using both in vivo and in vitro models, we are currently isolating several mechanisms that may contribute to this complex reorganization including laminin, tenascin and the expression of putative odor receptors in growth cones. In related studies we continue to characterize a unique population of glial cells, ensheathing cells, found in the olfactory nerve. While elsewhere in the mature CNS glia are an impediment to axon growth, the ensheathing cell glia support axon extension and targeting throughout life.
We recently demonstrated that the growth promoting effects of ensheathing cells are not limited to olfactory receptor neurons but are also seen in other populations of neurons. Particularly exciting, our recent studies demonstrate that the ensheathing cells remain pluri-potential and that when implanted into demyelinated spinal cord can adopt a myelinating phenotype which remyelinates the axons and contributes to a restoration of normal conduction velocities.
In parallel studies we are examining the molecular and synaptic organization of the olfactory bulb glomeruli. Using RT-PCR we are mapping the distribution of subsets of olfactory receptor cell axons in glomeruli to gain insights into the topography of odor-ligand maps in the olfactory bulb. In addition, working with colleagues, we are using a GFP tag to test hypotheses regarding the specificity of synaptic organization within glomeruli. Second, using antibodies synaptic vesicle related proteins and confocal microscopy we have begun to describe a hitherto unrecognized segregation of local and projection synaptic circuits in the glomeruli.
It may be that this segregation underlies the lateral inhibitory systems that are believed to be operative in the olfactory system. Beyond my colleagues in Neurosurgery, I maintain active collaborations with the following Departments at Yale: Neurology, Neurobiology, Anesthesiology and Ophthamology. In addition, I have collaborative studies with members of the faculty at Columbia University, Emory University, The Rockefeller, University of Maryland and University of Colorado.
Increasingly, the neurological sciences are focusing on intervention strategies that will both limit the debilitating consequences of injury/disease as well as increase the probability of successful regeneration of pathways and connections in the CNS. In order to facilitate these processes it is necessary for us to understand the molecular and cellular events operative during axon extension, target selection and synapse formation. The studies described above directly assess those questions and, particularly in the case of the ensheathing cells, offer the possibility of clinical application in the near future.
Fate mapping of olfactory bulb projection neurons
The role of axon:axon adhesion in establishing sensory maps
Cell surface and diffusible molecules influencing the extension and convergence of axons
The timing and molecular mechanisms mediating the development of 3-layer piriform cortex
Medical Subject Headings (MeSH)
Research at a Glance
Yale Co-Authors
Publications Timeline
Research Interests
Akiko Iwasaki, PhD
Eduardo Martin-Lopez
Publications
2024
Inflammatory Response and Defects on Myelin Integrity in the Olfactory System of K18hACE2 Mice Infected with SARS-CoV-2
Martin-Lopez E, Brennan B, Mao T, Spence N, Meller S, Han K, Yahiaoui N, Wang C, Iwasaki A, Greer C. Inflammatory Response and Defects on Myelin Integrity in the Olfactory System of K18hACE2 Mice Infected with SARS-CoV-2. ENeuro 2024, 11: eneuro.0106-24.2024. PMID: 38834299, PMCID: PMC11185043, DOI: 10.1523/eneuro.0106-24.2024.Peer-Reviewed Original ResearchAltmetricConceptsOlfactory bulbOlfactory epitheliumPiriform cortexOlfactory tractOlfactory systemSARS-CoV-2Projection neuronsMyelination defectsOlfactory sensory neuronsLateral olfactory tractLoss of olfactionRespiratory epithelial cellsLamina propria macrophagesSARS-CoV-2 infectionInfected SCDays of infectionIntegrity of myelinOlfactory dysfunctionInfected microgliaSensitive to infectionOlfactory deficitsSensory neuronsSustentacular cellsNasal cavityNeuronal conduction
2015
Dendrodendritic synapses in the mouse olfactory bulb external plexiform layer
Bartel DL, Rela L, Hsieh L, Greer CA. Dendrodendritic synapses in the mouse olfactory bulb external plexiform layer. The Journal Of Comparative Neurology 2015, 523: 1145-1161. PMID: 25420934, PMCID: PMC4390432, DOI: 10.1002/cne.23714.Peer-Reviewed Original ResearchCitationsAltmetricMeSH Keywords and ConceptsConceptsExternal plexiform layerDendrodendritic synapsesPlexiform layerSynaptic densityOlfactory bulb projection neuronsReciprocal dendrodendritic synapsesGranule cell spinesPostsynaptic scaffolding proteinOdor informationIR punctaProjection neuronsSecondary dendritesInhibitory synapsesT cellsInhibitory inputsCell synapseGranule cellsSynaptic circuitsSynaptic propertiesCell bodiesSynapsesCurrent spreadDendritesSynapseTemporal coding
2014
Segregated labeling of olfactory bulb projection neurons based on their birthdates
Imamura F, Greer CA. Segregated labeling of olfactory bulb projection neurons based on their birthdates. European Journal Of Neuroscience 2014, 41: 147-156. PMID: 25393912, PMCID: PMC4300262, DOI: 10.1111/ejn.12784.Peer-Reviewed Original ResearchCitationsAltmetricMeSH Keywords and ConceptsConceptsExternal plexiform layerMitral cell layerOlfactory bulb projection neuronsSuperficial external plexiform layerProjection neuronsMitral cellsOlfactory bulbInnervation patternSoma locationOB projection neuronsMain olfactory bulbAccessory olfactory bulbMouse olfactory bulbTiming of neurogenesisSecondary dendritesPlexiform layerCell dendritesBrdU injectionLaminar organizationUtero electroporationNeuronsDistinct subsetsEmbryonic dayCell layerMitralNonsensory target-dependent organization of piriform cortex
Chen CF, Zou DJ, Altomare CG, Xu L, Greer CA, Firestein SJ. Nonsensory target-dependent organization of piriform cortex. Proceedings Of The National Academy Of Sciences Of The United States Of America 2014, 111: 16931-16936. PMID: 25385630, PMCID: PMC4250170, DOI: 10.1073/pnas.1411266111.Peer-Reviewed Original ResearchCitationsAltmetricMeSH Keywords and ConceptsConceptsPiriform cortexOrbitofrontal cortexMouse piriform cortexOutput neuronsPrimary sensory cortexAssociation fiber systemsFluorescent retrograde tracingLateral orbitofrontal cortexRetrograde tracingEfferent componentsEfferent pathwaysAfferent inputEfferent projectionsOlfactory cortexOlfactory bulbAgranular insulaSensory cortexEfferent circuitsCortexOlfactory learning promotes input-specific synaptic plasticity in adult-born neurons
Lepousez G, Nissant A, Bryant AK, Gheusi G, Greer CA, Lledo PM. Olfactory learning promotes input-specific synaptic plasticity in adult-born neurons. Proceedings Of The National Academy Of Sciences Of The United States Of America 2014, 111: 13984-13989. PMID: 25189772, PMCID: PMC4183341, DOI: 10.1073/pnas.1404991111.Peer-Reviewed Original ResearchCitationsAltmetricMeSH Keywords and ConceptsConceptsAdult-born granule cellsAdult-born neuronsInput-specific synaptic plasticityOlfactory bulbGranule cellsOlfactory cortexSynaptic plasticityOptogenetic stimulationOlfactory learningSelective optogenetic stimulationOlfactory information processingCircuit remodelingCortical projectionsSpine densityAdult neurogenesisOB neuronsNew neuronsExcitatory inputsInhibitory inputsSynaptic mechanismsDendritic portionsDendritic treeNeuronsFunctional plasticityElectrophysiological analysis
2013
Pax6 regulates Tbr1 and Tbr2 expressions in olfactory bulb mitral cells
Imamura F, Greer CA. Pax6 regulates Tbr1 and Tbr2 expressions in olfactory bulb mitral cells. Molecular And Cellular Neuroscience 2013, 54: 58-70. PMID: 23353076, PMCID: PMC3622182, DOI: 10.1016/j.mcn.2013.01.002.Peer-Reviewed Original ResearchCitationsMeSH Keywords and ConceptsMeSH KeywordsAnimalsDNA-Binding ProteinsDopaminergic NeuronsEye ProteinsGABAergic NeuronsGene Expression Regulation, DevelopmentalHomeodomain ProteinsInterneuronsMiceMitosisNeural Stem CellsNeurogenesisNeurogliaOlfactory BulbPaired Box Transcription FactorsPAX6 Transcription FactorRepressor ProteinsT-Box Domain ProteinsConceptsExogenous expressionRegulation of Pax6Expression of Tbr1Mitral cell developmentCell precursorsFate determinationCell fateRadial glial cellsMitral cellsCell developmentTbr2 expressionPax6Embryonic olfactory bulbCortical projection neuronsOlfactory bulb mitral cellsPostmitotic precursorsPrecursor cellsUtero electroporationVentricular zoneNumber of cellsDopaminergic interneuronsTbr1Projection neuronsExpressionGlial cells
2011
Timing of neurogenesis is a determinant of olfactory circuitry
Imamura F, Ayoub AE, Rakic P, Greer CA. Timing of neurogenesis is a determinant of olfactory circuitry. Nature Neuroscience 2011, 14: 331-337. PMID: 21297629, PMCID: PMC3046046, DOI: 10.1038/nn.2754.Peer-Reviewed Original ResearchCitationsAltmetricMeSH Keywords and Concepts
2010
Developmental Dynamics of Piriform Cortex
Sarma AA, Richard MB, Greer CA. Developmental Dynamics of Piriform Cortex. Cerebral Cortex 2010, 21: 1231-1245. PMID: 21041199, PMCID: PMC3140179, DOI: 10.1093/cercor/bhq199.Peer-Reviewed Original ResearchCitationsMeSH Keywords and ConceptsMeSH KeywordsAge FactorsAnalysis of VarianceAnimalsAnimals, NewbornBromodeoxyuridineCell DifferentiationCerebral CortexEmbryo, MammalianFemaleGene Expression Regulation, DevelopmentalGlutamate DecarboxylaseGreen Fluorescent ProteinsIndolesMiceMice, TransgenicNerve Tissue ProteinsNeuronsNonlinear DynamicsPregnancyRatsConceptsAnterior piriform cortexPiriform cortexPyramidal cellsLayers IIPostnatal developmentCortical sensory processingNumber of interneuronsMolecular maturationCortical laminationInhibitory synapsesPostnatal eventsInhibitory networksSensory processingOdor codingPaleocortexCortexMorphological basisCellsMaturationInterneuronsNeocortexSynapsesAge-induced disruption of selective olfactory bulb synaptic circuits
Richard MB, Taylor SR, Greer CA. Age-induced disruption of selective olfactory bulb synaptic circuits. Proceedings Of The National Academy Of Sciences Of The United States Of America 2010, 107: 15613-15618. PMID: 20679234, PMCID: PMC2932573, DOI: 10.1073/pnas.1007931107.Peer-Reviewed Original ResearchCitationsAltmetricMeSH Keywords and ConceptsConceptsMouse OBLayer-specific alterationsAfferent synaptic inputExternal plexiform layerPrimary sensory cortexAge-related alterationsAge-related cognitive deficitsNeuronal lossOlfactory bulb circuitryProjection neuronsPlexiform layerOB glomeruliQuantitative morphometric analysisSynaptic densityGlomerular layerInterneuron subpopulationsOlfactory functionOSN axonsSynaptic inputsSensory cortexOB layersSynaptic circuitsSensory functionOB circuitryCognitive deficits
2009
Dendritic Branching of Olfactory Bulb Mitral and Tufted Cells: Regulation by TrkB
Imamura F, Greer CA. Dendritic Branching of Olfactory Bulb Mitral and Tufted Cells: Regulation by TrkB. PLOS ONE 2009, 4: e6729. PMID: 19707543, PMCID: PMC2727791, DOI: 10.1371/journal.pone.0006729.Peer-Reviewed Original ResearchCitationsMeSH Keywords and ConceptsConceptsMitral/TrkB activationOlfactory bulbApical dendritesDendritic developmentLateral dendriteDendritic branchingExternal plexiform layerReciprocal dendrodendritic synapsesEarly postnatal daysOlfactory bulb mitralTrkB neurotrophin receptorMammalian olfactory bulbSame odor receptorOlfactory sensory neuronsTufted CellsDendrodendritic synapsesTrkB receptorsDendritic differentiationOB neuronsProjection neuronsPlexiform layerNeurotrophin receptorPostnatal daySensory neurons
Academic Achievements and Community Involvement
activity Development
ResearchDetails01/01/2015 - PresentParis, Ile-de-France, FranceAbstract/SynopsisCollaborative projects on the molecular development of synaptic circuits
activity mRNA translation in axons
ResearchDetails01/01/2015 - PresentParis, Ile-de-France, FranceAbstract/SynopsisA collaborative effort to understand the role of locally translated mRNA in the targeting specificity of axons
honor Distinguished Professor
International AwardUniversite Pierre et Marie Curie, Paris, FranceDetails09/01/2013United Stateshonor Max Mozell Award for Outstanding Achievements in the Chemical Senses
International AwardAssociation for Chemoreception SciencesDetails01/01/2009United Stateshonor Distinguished Visiting Professor
UnknownSimon Fraser University, Vancouver, British Columbia, CanadaDetails01/01/2003United States
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