Research Topics
| Fritjof HelmchenSummaryAffiliation: Abteilung Zellphysiologie Country: Germany Publications
| Collaborators
|
Detail Information
Publications
Ca2+ imaging in the mammalian brain in vivoFritjof Helmchen
Abteilung Zellphysiologie, Max Planck Insitut für medizinische Forschung, Jahnstr 29, 69120 Heidelberg, Germany
Eur J Pharmacol 447:119-29. 2002....- Raising the speed limit--fast Ca(2+) handling in dendritic spinesFritjof 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... - New developments in multiphoton microscopyFritjof 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... - Miniaturization of fluorescence microscopes using fibre opticsFritjof 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... - Dendritic spikes in apical dendrites of neocortical layer 2/3 pyramidal neuronsMatthew 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... 
Lentivirus-based genetic manipulations of cortical neurons and their optical and electrophysiological monitoring in vivoTanjew 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...- Imaging input and output of neocortical networks in vivoJason 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... - Calcium indicator loading of neurons using single-cell electroporationThomas Nevian
Abteilung Zellphysiologie, Max Planck Institut fur medizinische Forschung, Jahnstrasse 29, 69120 Heidelberg, Germany
Pflugers Arch 454:675-88. 2007.... - Boosting of action potential backpropagation by neocortical network activity in vivoJack 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... - Background synaptic activity is sparse in neocortexJack 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... - Sulforhodamine 101 as a specific marker of astroglia in the neocortex in vivoAxel Nimmerjahn
Abteilung Zellphysiologie, , 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... - Resting microglial cells are highly dynamic surveillants of brain parenchyma in vivoAxel Nimmerjahn
Abteilung Zellphysiologie, , Jahnstrasse 29, 69120 Heidelberg, Germany
Science 308:1314-8. 2005..Microglia thus are busy and vigilant housekeepers in the adult brain... - Miniaturized two-photon microscope based on a flexible coherent fiber bundle and a gradient-index lens objectiveWerner 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... - Supralinear Ca2+ influx into dendritic tufts of layer 2/3 neocortical pyramidal neurons in vitro and in vivoJack 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... - Nonlinear anisotropic diffusion filtering of three-dimensional image data from two-photon microscopyPhilip 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... - Sindbis vector SINrep(nsP2S726): a tool for rapid heterologous expression with attenuated cytotoxicity in neuronsJinhyun 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... - Imaging cellular network dynamics in three dimensions using fast 3D laser scanningWerner 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... - In vivo calcium imaging of circuit activity in cerebellar cortexMegan 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... - New angles on neuronal dendrites in vivoWerner 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... - Spatial organization of neuronal population responses in layer 2/3 of rat barrel cortexJason 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... - In vivo calcium imaging of neural network functionWerner 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... - Ultra-compact fiber-optic two-photon microscope for functional fluorescence imaging in vivoChristoph 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... - Novel approaches to monitor and manipulate single neurons in vivoMichael Brecht
Department of Neuroscience, Erasmus Medical Center, University Medical Center Rotterdam, 3015 DR Rotterdam, The Netherlands
J Neurosci 24:9223-7. 2004 - Deep tissue two-photon microscopyFritjof 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... - Little strokes fill big oaks: a simple in vivo stain of brain cellsFritjof 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...