Fritjof Helmchen

Summary

Affiliation: Abteilung Zellphysiologie
Country: Germany

Publications

  1. ncbi request reprint Raising the speed limit--fast Ca(2+) handling in dendritic spines
    Fritjof Helmchen
    Abteilung Zellphysiologie, Max Planck Institute für medizinische Forschung, Jahnstr 29, 69120 Heidelberg, Germany
    Trends Neurosci 25:438-41; discussion 441. 2002
  2. ncbi request reprint Ca2+ imaging in the mammalian brain in vivo
    Fritjof Helmchen
    Abteilung Zellphysiologie, Max Planck Insitut für medizinische Forschung, Jahnstr 29, 69120 Heidelberg, Germany
    Eur J Pharmacol 447:119-29. 2002
  3. ncbi request reprint New developments in multiphoton microscopy
    Fritjof Helmchen
    Abt Zellphysiologie, Max Planck Institut fur medizinische Forschung, Jahnstrasse 29, Heidelberg, Germany
    Curr Opin Neurobiol 12:593-601. 2002
  4. ncbi request reprint Miniaturization of fluorescence microscopes using fibre optics
    Fritjof Helmchen
    Abteilung Zellphysiologie, Max Planck Insitut für medizinische Forschung, Jahnstrasse 29, 69120 Heidelberg, Germany
    Exp Physiol 87:737-45. 2002
  5. ncbi request reprint Dendritic spikes in apical dendrites of neocortical layer 2/3 pyramidal neurons
    Matthew Evan Larkum
    Abteilung Zellphysiologie, Max Planck Institut fur medizinische Forschung, D 69120 Heidelberg, Germany
    J Neurosci 27:8999-9008. 2007
  6. pmc Lentivirus-based genetic manipulations of cortical neurons and their optical and electrophysiological monitoring in vivo
    Tanjew Dittgen
    Department of Molecular Neurobiology, Max Planck Institute for Medical Research, Jahnstrasse 29, 69120 Heidelberg, Germany
    Proc Natl Acad Sci U S A 101:18206-11. 2004
  7. pmc Imaging input and output of neocortical networks in vivo
    Jason N D Kerr
    Department of Cell Physiology, Max Planck Institute for Medical Research, Jahnstrasse 29, D 69120 Heidelberg, Germany
    Proc Natl Acad Sci U S A 102:14063-8. 2005
  8. ncbi request reprint Calcium indicator loading of neurons using single-cell electroporation
    Thomas Nevian
    Abteilung Zellphysiologie, Max Planck Institut fur medizinische Forschung, Jahnstrasse 29, 69120 Heidelberg, Germany
    Pflugers Arch 454:675-88. 2007
  9. ncbi request reprint Boosting of action potential backpropagation by neocortical network activity in vivo
    Jack Waters
    Abteilung Zellphysiologie, Max Planck Institut fur medizinische Forschung, 69120 Heidelberg, Germany
    J Neurosci 24:11127-36. 2004
  10. ncbi request reprint Background synaptic activity is sparse in neocortex
    Jack Waters
    Abteilung Zellphysiologie, Max Planck Institut fur medizinische Forschung, 69120 Heidelberg, Germany
    J Neurosci 26:8267-77. 2006

Collaborators

Detail Information

Publications25

  1. ncbi request reprint Raising the speed limit--fast Ca(2+) handling in dendritic spines
    Fritjof Helmchen
    Abteilung Zellphysiologie, Max Planck Institute für medizinische Forschung, Jahnstr 29, 69120 Heidelberg, Germany
    Trends Neurosci 25:438-41; discussion 441. 2002
    ..In addition structural factors, such as shape and dendritic location, could contribute to fine-tuning of spine Ca2+ handling and synaptic modification...
  2. ncbi request reprint Ca2+ imaging in the mammalian brain in vivo
    Fritjof Helmchen
    Abteilung Zellphysiologie, Max Planck Insitut für medizinische Forschung, Jahnstr 29, 69120 Heidelberg, Germany
    Eur J Pharmacol 447:119-29. 2002
    ....
  3. ncbi request reprint New developments in multiphoton microscopy
    Fritjof Helmchen
    Abt Zellphysiologie, Max Planck Institut fur medizinische Forschung, Jahnstrasse 29, Heidelberg, Germany
    Curr Opin Neurobiol 12:593-601. 2002
    ..In addition, nonlinear optical contrast mechanisms other than multiphoton excitation of fluorescence are being explored...
  4. ncbi request reprint Miniaturization of fluorescence microscopes using fibre optics
    Fritjof Helmchen
    Abteilung Zellphysiologie, Max Planck Insitut für medizinische Forschung, Jahnstrasse 29, 69120 Heidelberg, Germany
    Exp Physiol 87:737-45. 2002
    ..Here, we review technological approaches to build miniaturized fluorescence microscopes and discuss their potential applications...
  5. ncbi request reprint Dendritic spikes in apical dendrites of neocortical layer 2/3 pyramidal neurons
    Matthew Evan Larkum
    Abteilung Zellphysiologie, Max Planck Institut fur medizinische Forschung, D 69120 Heidelberg, Germany
    J Neurosci 27:8999-9008. 2007
    ..We conclude that L2/3 pyramidal neurons can generate dendritic spikes, sharing with L5 pyramidal neurons fundamental properties of dendritic excitability and control by inhibition...
  6. pmc Lentivirus-based genetic manipulations of cortical neurons and their optical and electrophysiological monitoring in vivo
    Tanjew Dittgen
    Department of Molecular Neurobiology, Max Planck Institute for Medical Research, Jahnstrasse 29, 69120 Heidelberg, Germany
    Proc Natl Acad Sci U S A 101:18206-11. 2004
    ..This approach is ideally suited for analysis of gene functions in individual neurons in the intact brain...
  7. pmc Imaging input and output of neocortical networks in vivo
    Jason N D Kerr
    Department of Cell Physiology, Max Planck Institute for Medical Research, Jahnstrasse 29, D 69120 Heidelberg, Germany
    Proc Natl Acad Sci U S A 102:14063-8. 2005
    ..The dissection of the various signal components in bulk-loaded tissue as demonstrated here will enable further studies of signal flow through cortical networks...
  8. ncbi request reprint Calcium indicator loading of neurons using single-cell electroporation
    Thomas Nevian
    Abteilung Zellphysiologie, Max Planck Institut fur medizinische Forschung, Jahnstrasse 29, 69120 Heidelberg, Germany
    Pflugers Arch 454:675-88. 2007
    ....
  9. ncbi request reprint Boosting of action potential backpropagation by neocortical network activity in vivo
    Jack Waters
    Abteilung Zellphysiologie, Max Planck Institut fur medizinische Forschung, 69120 Heidelberg, Germany
    J Neurosci 24:11127-36. 2004
    ..Hence, somatic feedback to the dendrites becomes stronger with increasing network activity...
  10. ncbi request reprint Background synaptic activity is sparse in neocortex
    Jack Waters
    Abteilung Zellphysiologie, Max Planck Institut fur medizinische Forschung, 69120 Heidelberg, Germany
    J Neurosci 26:8267-77. 2006
    ..These conditions enhance the effectiveness of each synapse at depolarized potentials. Hence, neocortical networks are relatively quiet at rest, and the effect of synaptic background is weaker than previously thought...
  11. ncbi request reprint Sulforhodamine 101 as a specific marker of astroglia in the neocortex in vivo
    Axel Nimmerjahn
    Abteilung Zellphysiologie, Max Planck Institut fur medizinische Forschung, Jahnstr 29, 69120 Heidelberg, Germany
    Nat Methods 1:31-7. 2004
    ..We expect SR101 staining to become a principal tool for investigating astroglia in vivo...
  12. ncbi request reprint Resting microglial cells are highly dynamic surveillants of brain parenchyma in vivo
    Axel Nimmerjahn
    Abteilung Zellphysiologie, Max Planck Institut fur medizinische Forschung, Jahnstrasse 29, 69120 Heidelberg, Germany
    Science 308:1314-8. 2005
    ..Microglia thus are busy and vigilant housekeepers in the adult brain...
  13. ncbi request reprint Miniaturized two-photon microscope based on a flexible coherent fiber bundle and a gradient-index lens objective
    Werner Göbel
    Max Planck Institut fur medizinische Forschung, Jahnstrasse 29, 69120 Heidelberg, Germany
    Opt Lett 29:2521-3. 2004
    ..Micrometer-sized fluorescent beads and pollen grains were readily resolved. In addition, fluorescently labeled blood vessels were imaged through the fiber bundle in rat brain in vivo...
  14. ncbi request reprint Supralinear Ca2+ influx into dendritic tufts of layer 2/3 neocortical pyramidal neurons in vitro and in vivo
    Jack Waters
    Abteilung Zellphysiologie, Max Planck Institut fur medizinische Forschung, 69120 Heidelberg, Germany
    J Neurosci 23:8558-67. 2003
    ..This dendritic supralinearity enables layer 2/3 neurons to integrate ascending sensory input from layer 4 and associative input to layer 1...
  15. ncbi request reprint Nonlinear anisotropic diffusion filtering of three-dimensional image data from two-photon microscopy
    Philip J Broser
    Max Planck Institut fur medizinische Forschung, Abteilung Zellphysiologie, Jahnstr 29, D 69120, Heidelberg, Germany
    J Biomed Opt 9:1253-64. 2004
    ..The filter is a valuable general tool for smoothing cellular processes and is well suited for preparing data for subsequent image segmentation and neuron reconstruction...
  16. ncbi request reprint Sindbis vector SINrep(nsP2S726): a tool for rapid heterologous expression with attenuated cytotoxicity in neurons
    Jinhyun Kim
    Max Planck Institute for Medical Research, Department of Molecular Neurobiology, Jahnstrasse 29, 69120 Heidelberg, Germany
    J Neurosci Methods 133:81-90. 2004
    ..As an experimental example, we demonstrate the applicability of this system for high-resolution two-photon imaging of dendritic spines in vivo...
  17. ncbi request reprint Imaging cellular network dynamics in three dimensions using fast 3D laser scanning
    Werner Göbel
    Department of Neurophysiology, Brain Research Institute, University of Zurich, Winterthurerstr 190, CH 8057 Zurich, Switzerland
    Nat Methods 4:73-9. 2007
    ..Two-photon population imaging using 3D scanning opens the field for comprehensive studies of local network dynamics in intact tissue...
  18. ncbi request reprint In vivo calcium imaging of circuit activity in cerebellar cortex
    Megan R Sullivan
    Department of Molecular Biology, Princeton University, Princeton, New Jersey, Princeton, NJ 08544, USA
    J Neurophysiol 94:1636-44. 2005
    ..Two-photon calcium imaging of bulk-loaded cerebellar cortex is thus well suited to optically monitor synaptic processing in the intact cerebellum...
  19. ncbi request reprint New angles on neuronal dendrites in vivo
    Werner Göbel
    Department of Neurophysiology, Brain Research Institute, Winterthurerstr 190, CH 8057, Zurich, Switzerland
    J Neurophysiol 98:3770-9. 2007
    ..These novel scanning modes will facilitate optical probing of dendritic function in vivo...
  20. ncbi request reprint Spatial organization of neuronal population responses in layer 2/3 of rat barrel cortex
    Jason N D Kerr
    Department of Cell Physiology, Max Planck Institute for Medical Research, D 69120 Heidelberg, Germany
    J Neurosci 27:13316-28. 2007
    ..We conclude that, despite their sparseness and variability, L2/3 population responses show a clear spatial organization on the columnar scale...
  21. ncbi request reprint In vivo calcium imaging of neural network function
    Werner Göbel
    Department of Neurophysiology, Brain Research Institute, University of Zurich, Zurich, Switzerland
    Physiology (Bethesda) 22:358-65. 2007
    ..In this review, we discuss basic aspects of in vivo calcium imaging and highlight recent developments that will help to uncover operating principles of neural circuits...
  22. ncbi request reprint Ultra-compact fiber-optic two-photon microscope for functional fluorescence imaging in vivo
    Christoph J Engelbrecht
    Dept of Neurophysiology, Brain Research Institute, University of Zurich, Winterthurerstrasse 190, CH 8057 Zurich, Switzerland
    Opt Express 16:5556-64. 2008
    ..The microscope will be easily portable by a rat or mouse and thus should enable functional imaging in freely behaving animals...
  23. ncbi request reprint Novel approaches to monitor and manipulate single neurons in vivo
    Michael Brecht
    Department of Neuroscience, Erasmus Medical Center, University Medical Center Rotterdam, 3015 DR Rotterdam, The Netherlands
    J Neurosci 24:9223-7. 2004
  24. ncbi request reprint Deep tissue two-photon microscopy
    Fritjof Helmchen
    Department of Neurophysiology, Brain Research Institute, University of Zurich, CH 8057 Zurich, Switzerland
    Nat Methods 2:932-40. 2005
    ..Here we review fundamental concepts of nonlinear microscopy and discuss conditions relevant for achieving large imaging depths in intact tissue...
  25. ncbi request reprint Little strokes fill big oaks: a simple in vivo stain of brain cells
    Fritjof Helmchen
    Department of Neurophysiology, Brain Research Institute, University of Zurich, CH 8057 Zurich, Switzerland
    Neuron 53:771-3. 2007
    ..Neuronal populations are sparsely labeled, preserving the ability to resolve calcium signals in dendrites and synaptic structures...