T Knopfel

Summary

Affiliation: RIKEN Brain Science Institute
Country: Japan

Publications

  1. pmc Engineering and characterization of an enhanced fluorescent protein voltage sensor
    Dimitar Dimitrov
    Laboratory for Neuronal Circuit Dynamics, Brain Science Institute, RIKEN, Saitama, Japan
    PLoS ONE 2:e440. 2007
  2. pmc Optical imaging as a link between cellular neurophysiology and circuit modeling
    Walther Akemann
    Laboratory for Neuronal Circuit Dynamics, RIKEN Brain Science Institute Wako, Japan
    Front Cell Neurosci 3:5. 2009
  3. pmc Exploration of fluorescent protein voltage probes based on circularly permuted fluorescent proteins
    Sunita Ghimire Gautam
    Laboratory for Neuronal Circuit Dynamics, RIKEN Brain Science Institute Saitama, Japan
    Front Neuroeng 2:14. 2009
  4. pmc Second and third generation voltage-sensitive fluorescent proteins for monitoring membrane potential
    Amelie Perron
    Laboratory for Neuronal Circuit Dynamics, RIKEN Brain Science Institute Wako Shi, Japan
    Front Mol Neurosci 2:5. 2009
  5. pmc Functional integration of calcium regulatory mechanisms at Purkinje neuron synapses
    Ruth M Empson
    Department of Physiology, Brain Health and Repair Research Centre, University of Otago School of Medical Sciences, Dunedin, New Zealand
    Cerebellum 11:640-50. 2012
  6. pmc Functional classification of neurons in the mouse lateral cerebellar nuclei
    Marylka Uusisaari
    Laboratory for Neuronal Circuit Dynamics, RIKEN Brain Science Institute, Wako Shi, Saitama, Japan
    Cerebellum 10:637-46. 2011
  7. pmc GlyT2+ neurons in the lateral cerebellar nucleus
    Marylka Uusisaari
    Laboratory for Neuronal Circuit Dynamics, Brain Science Institute, RIKEN, Wako Shi, Saitama, Japan
    Cerebellum 9:42-55. 2010
  8. pmc Interaction of Cupidin/Homer2 with two actin cytoskeletal regulators, Cdc42 small GTPase and Drebrin, in dendritic spines
    Yoko Shiraishi-Yamaguchi
    Laboratory for Molecular Neurogenesis, RIKEN Brain Science Institute, Wako, Saitama 351 0198, Japan
    BMC Neurosci 10:25. 2009
  9. ncbi request reprint Modulation of excitation by metabotropic glutamate receptors
    Thomas Knopfel
    Laboratory for Neuronal Circuit Dynamics, RIKEN Brain Science Institute, 2 1 Hirosawa, Wako Shi, 351 0198 Saitama, Japan
    Results Probl Cell Differ 44:163-75. 2008
  10. pmc Toward the second generation of optogenetic tools
    Thomas Knopfel
    Laboratory for Neuronal Circuit Dynamics, RIKEN Brain Science Institute, Wako Shi, Saitama 351 0198, Japan
    J Neurosci 30:14998-5004. 2010

Collaborators

Detail Information

Publications42

  1. pmc Engineering and characterization of an enhanced fluorescent protein voltage sensor
    Dimitar Dimitrov
    Laboratory for Neuronal Circuit Dynamics, Brain Science Institute, RIKEN, Saitama, Japan
    PLoS ONE 2:e440. 2007
    ..The use of presently known voltage sensor proteins is limited by incorrect subcellular localization and small or absent voltage responses in mammalian cells...
  2. pmc Optical imaging as a link between cellular neurophysiology and circuit modeling
    Walther Akemann
    Laboratory for Neuronal Circuit Dynamics, RIKEN Brain Science Institute Wako, Japan
    Front Cell Neurosci 3:5. 2009
    ..Here we review the potential of optical imaging techniques to serve this purpose...
  3. pmc Exploration of fluorescent protein voltage probes based on circularly permuted fluorescent proteins
    Sunita Ghimire Gautam
    Laboratory for Neuronal Circuit Dynamics, RIKEN Brain Science Institute Saitama, Japan
    Front Neuroeng 2:14. 2009
    ..Even so their voltage sensitivity was relatively modest, they constitute a proof of principle for this novel protein design...
  4. pmc Second and third generation voltage-sensitive fluorescent proteins for monitoring membrane potential
    Amelie Perron
    Laboratory for Neuronal Circuit Dynamics, RIKEN Brain Science Institute Wako Shi, Japan
    Front Mol Neurosci 2:5. 2009
    ..Here, we review the development and current status of these novel fluorescent probes...
  5. pmc Functional integration of calcium regulatory mechanisms at Purkinje neuron synapses
    Ruth M Empson
    Department of Physiology, Brain Health and Repair Research Centre, University of Otago School of Medical Sciences, Dunedin, New Zealand
    Cerebellum 11:640-50. 2012
    ....
  6. pmc Functional classification of neurons in the mouse lateral cerebellar nuclei
    Marylka Uusisaari
    Laboratory for Neuronal Circuit Dynamics, RIKEN Brain Science Institute, Wako Shi, Saitama, Japan
    Cerebellum 10:637-46. 2011
    ..In addition to their differential use of neurotransmitters (glutamate, GABA, or glycine), these cell types also receive and provide synaptic information from different sources and to different targets...
  7. pmc GlyT2+ neurons in the lateral cerebellar nucleus
    Marylka Uusisaari
    Laboratory for Neuronal Circuit Dynamics, Brain Science Institute, RIKEN, Wako Shi, Saitama, Japan
    Cerebellum 9:42-55. 2010
    ..Presence of this so far undescribed DCN neuron population in the lateral nucleus suggests a direct inhibitory pathway from the DCN to the cerebellar cortex...
  8. pmc Interaction of Cupidin/Homer2 with two actin cytoskeletal regulators, Cdc42 small GTPase and Drebrin, in dendritic spines
    Yoko Shiraishi-Yamaguchi
    Laboratory for Molecular Neurogenesis, RIKEN Brain Science Institute, Wako, Saitama 351 0198, Japan
    BMC Neurosci 10:25. 2009
    ..In this study, we aimed to elucidate the structural and functional properties of the interaction between Cupidin/Homer2 and two actin-cytoskeletal regulators, Cdc42 small GTPase and Drebrin...
  9. ncbi request reprint Modulation of excitation by metabotropic glutamate receptors
    Thomas Knopfel
    Laboratory for Neuronal Circuit Dynamics, RIKEN Brain Science Institute, 2 1 Hirosawa, Wako Shi, 351 0198 Saitama, Japan
    Results Probl Cell Differ 44:163-75. 2008
    ....
  10. pmc Toward the second generation of optogenetic tools
    Thomas Knopfel
    Laboratory for Neuronal Circuit Dynamics, RIKEN Brain Science Institute, Wako Shi, Saitama 351 0198, Japan
    J Neurosci 30:14998-5004. 2010
    ..In this review, we will evaluate and highlight the limitations of presently available optogenic tools and discuss where these technologies and their applications are headed in the future...
  11. pmc Two new non-competitive mGlu1 receptor antagonists are potent tools to unravel functions of this mGlu receptor subtype
    T Knopfel
    Laboratory for Neuronal Circuit Dynamics, RIKEN BSI, Wako Shi, Saitama, Japan
    Br J Pharmacol 151:723-4. 2007
    ....
  12. doi request reprint Optogenetic monitoring of membrane potentials
    Hiroki Mutoh
    RIKEN Brain Science Institute, Laboratory for Neuronal Circuit Dynamics, 2 1 Hirosawa, Wako Shi, Saitama, 351 0198, Japan
    Exp Physiol 96:13-8. 2011
    ..Here we examine the current state of this subfield of optogenetics, address current limitations and challenges, and discuss what is likely to be feasible in the near future...
  13. ncbi request reprint Optical probing of neuronal circuit dynamics: genetically encoded versus classical fluorescent sensors
    Thomas Knopfel
    Laboratory for Neuronal Circuit Dynamics, RIKEN Brain Science Institute, 2 1 Hirosawa, Wako Shi, Saitama 351 0198 Japan
    Trends Neurosci 29:160-6. 2006
    ....
  14. ncbi request reprint Olfactory nerve stimulation-induced calcium signaling in the mitral cell distal dendritic tuft
    Q Yuan
    Laboratory for Neuronal Circuit Dynamics, Brain Science Institute, RIKEN, Saitama, Japan
    J Neurophysiol 95:2417-26. 2006
    ..The synaptically induced Ca2+ signals reflect, at least in part, dendrodendritic interactions that support intraglomerular coupling of MCs and generation of an output that is common to all MCs associated with one glomerulus...
  15. ncbi request reprint Functional topology of the mossy fibre-granule cell--Purkinje cell system revealed by imaging of intrinsic fluorescence in mouse cerebellum
    V Coutinho
    Laboratory for Neuronal Circuit Dynamics, Brain Science Institute, RIKEN, 2 1 Hirosawa, Wako Shi, Saitama 351 0198, Japan
    Eur J Neurosci 20:740-8. 2004
    ....
  16. doi request reprint GABAergic synaptic communication in the GABAergic and non-GABAergic cells in the deep cerebellar nuclei
    M Uusisaari
    Laboratory for Neuronal Circuit Dynamics, Brain Science Institute, RIKEN, 2 1 Hirosawa, Wako Shi, Saitama, 351 0198, Japan
    Neuroscience 156:537-49. 2008
    ..Rather, the main differentiating factor appears to be the dendritic localization of GABAergic synapses in the GABAergic cells...
  17. ncbi request reprint Olfactory nerve stimulation-evoked mGluR1 slow potentials, oscillations, and calcium signaling in mouse olfactory bulb mitral cells
    Q Yuan
    Laboratory for Neuronal Circuit Dynamics, RIKEN Brain Science Institute, Wako Shi, Saitama, 351 0198, Japan
    J Neurophysiol 95:3097-104. 2006
    ..We conclude that the MC mGluR1 potential triggered by glutamate released from the ON supports oscillations and synchronizations of MCs associated within one glomerulus...
  18. ncbi request reprint Glutamate uptake controls expression of a slow postsynaptic current mediated by mGluRs in cerebellar Purkinje cells
    W Reichelt
    Laboratory for Neuronal Circuit Dynamics, Brain Science Institute, RIKEN, Saitama 351 0198, Japan
    J Neurophysiol 87:1974-80. 2002
    ..Thus in contrast to fast glutamatergic synaptic transmission, metabotropic glutamate receptor-mediated transmission is critically dependent on the activity and capacity of glutamate uptake...
  19. doi request reprint Targeted optical probing of neuronal circuit dynamics using fluorescent protein sensors
    De lai Qiu
    Laboratory for Neuronal Circuit Dynamics, RIKEN Brain Science Institute, Wako City, Saitama, Japan
    Neurosignals 16:289-99. 2008
    ..In this review we describe the advance of these emerging optical techniques and compare them with more conventional approaches...
  20. ncbi request reprint Metabotropic glutamate receptors: electrical and chemical signaling properties
    Victoria Coutinho
    Laboratory for Neuronal Circuit Dynamics, Brain Science Institute, RIKEN, Saitama, Japan
    Neuroscientist 8:551-61. 2002
    ..The classical role of glutamate as a fast excitatory synaptic transmitter was largely extended by mGluRs acting as a neuromodulator and even as an activator of inhibitory mechanisms at certain synapses...
  21. ncbi request reprint Metabotropic glutamate receptors in the cerebellum with a focus on their function in Purkinje cells
    Thomas Knopfel
    Laboratory for Neuronal Circuit Dynamics, RIKEN Brain Science Institute, Wako Shi, Saitama, Japan
    Cerebellum 1:19-26. 2002
    ..We discuss the mechanism underlying the mGluR1-mediated postsynaptic current as well as current theories on the role of mGluR1 in parallel fiber-Purkinje cell long-term depression...
  22. ncbi request reprint Optical recordings of membrane potential using genetically targeted voltage-sensitive fluorescent proteins
    Thomas Knopfel
    Laboratory for Neuronal Circuit Dynamics, Brain Science Institute, RIKEN, 2 1 Hirosawa, Wako Shi, Saitama 351 0198, Japan
    Methods 30:42-8. 2003
    ..Here, we discuss the methodology, applications, and potential advantages of this novel technique...
  23. pmc Calcium signaling in mitral cell dendrites of olfactory bulbs of neonatal rats and mice during olfactory nerve Stimulation and beta-adrenoceptor activation
    Qi Yuan
    Laboratory for Neuronal Circuit Dynamics, Brain Science Institute, RIKEN, Wako Shi, Saitama, 351 0198, Japan
    Learn Mem 11:406-11. 2004
    ..The absence of beta-adrenergic modulation on either electrical or calcium signaling at ON-MC synapses of neonatal rats and mice excludes the involvement of this mechanism in early odor preference learning...
  24. ncbi request reprint Transgenic mice expressing a pH and Cl- sensing yellow-fluorescent protein under the control of a potassium channel promoter
    Friedrich Metzger
    Laboratory for Neuronal Circuit Dynamics, Brain Science Institute, RIKEN, 2 1 Hirosawa, Wako Shi, Saitama 351 0198, Japan
    Eur J Neurosci 15:40-50. 2002
    ..We conclude that transgenic mice expressing GFP-derived sensors under the control of cell-type specific promoters, provide a unique opportunity for functional characterization of defined subsets of neurons...
  25. ncbi request reprint Glutamate-induced elevations in intracellular chloride concentration in hippocampal cell cultures derived from EYFP-expressing mice
    Jennifer E Slemmer
    Laboratory for Neuronal Circuit Dynamics, Brain Science Institute, RIKEN, 2 1 Hirosawa, Wako Shi, Saitama 351 0198, Japan
    Eur J Neurosci 19:2915-22. 2004
    ..The present study highlights the vulnerability of [Cl(-)](i) homeostasis after membrane depolarization in neurons...
  26. ncbi request reprint Activation of cerebellar parallel fibers monitored in transgenic mice expressing a fluorescent Ca2+ indicator protein
    Javier Diez-Garcia
    Laboratory for Neuronal Circuit Dynamics, RIKEN Brain Science Institute, 2 1 Hirosawa, Saitama 351 0198, Japan
    Eur J Neurosci 22:627-35. 2005
    ..We found that paired pulse-induced presynaptic Ca2+ transients of parallel fibers are not affected by blockade of N-methyl-D-aspartate receptors...
  27. pmc Cortex-restricted disruption of NMDAR1 impairs neuronal patterns in the barrel cortex
    T Iwasato
    Laboratory for Behavioral Genetics, Brain Science Institute, RIKEN, Saitama, Japan
    Nature 406:726-31. 2000
    ..Our findings indicate that cortical NMDARs are essential for the aggregation of layer IV cells into barrels and for development of the full complement of thalamocortical patterns...
  28. ncbi request reprint An NMDA receptor/nitric oxide cascade in presynaptic parallel fiber-Purkinje neuron long-term potentiation
    De lai Qiu
    Laboratory for Neuronal Circuit Dynamics, RIKEN Brain Science Institute, Saitama 351 0198, Japan
    J Neurosci 27:3408-15. 2007
    ..Blockade of NMDA receptors did not affect the PF Ca2+ transients induced during 4 Hz stimulation, indicating that the NMDA receptors required for the induction of presynaptic PF LTP are not localized in PFs...
  29. pmc Red-shifted voltage-sensitive fluorescent proteins
    Amelie Perron
    Laboratory for Neuronal Circuit Dynamics, RIKEN Brain Science Institute, Wako Shi, Saitama 351 0198, Japan
    Chem Biol 16:1268-77. 2009
    ....
  30. pmc Effect of voltage sensitive fluorescent proteins on neuronal excitability
    Walther Akemann
    Laboratory for Neuronal Circuit Dynamics, RIKEN Brain Science Institute, Wako City, Saitama 351 0198, Japan
    Biophys J 96:3959-76. 2009
    ..Yet, the simulations indicate that significant improvement of existing probes will still be required to report action potentials in individual neurons in mammalian brain tissue in single trials...
  31. ncbi request reprint In vivo calcium imaging from genetically specified target cells in mouse cerebellum
    Javier Diez-Garcia
    Laboratory for Neuronal Circuit Dynamics, RIKEN Brain Science Institute, 2 1 Hirosawa, Wako Shi, Saitama 351 0198, Japan
    Neuroimage 34:859-69. 2007
    ..We expect that genetically targeted fluorescent calcium indicator proteins along with optical imaging techniques will be instrumental for the construction of macroscopic and microscopic maps of the function of specific brain circuits...
  32. doi request reprint Presynaptically expressed long-term depression at cerebellar parallel fiber synapses
    De lai Qiu
    Laboratory for Neuronal Circuit Dynamics, RIKEN Brain Science Institute, 2 1 Hirosawa, Wako Shi, Saitama, 351 0198, Japan
    Pflugers Arch 457:865-75. 2009
    ..We conclude that bidirectional plasticity mechanisms exist for both presynaptic and postsynaptic components of cerebellar learning...
  33. ncbi request reprint Morphological and electrophysiological properties of GABAergic and non-GABAergic cells in the deep cerebellar nuclei
    Marylka Uusisaari
    Laboratory for Neuronal Circuit Dynamics, Brain Science Institute, RIKEN, 2 1 Hirosawa, Wako Shi, Saitama 351 0198, Japan
    J Neurophysiol 97:901-11. 2007
    ..We conclude that GABAergic DCN neurons are specialized to convey phasic spike rate information, whereas tonic spike rate is more faithfully relayed by the large non-GABAergic cells...
  34. ncbi request reprint Climbing fiber-triggered metabotropic slow potentials enhance dendritic calcium transients and simple spike firing in cerebellar Purkinje cells
    Qi Yuan
    Laboratory for Neuronal Circuit Dynamics, Brain Science Institute, RIKEN, 2 1 Hirosawa, Wako Shi, Saitama 351 0198, Japan
    Mol Cell Neurosci 35:596-603. 2007
    ..In turn, these CF-triggered slow mGluR potentials enhance the complex spike-associated calcium signals throughout the dendrite. Moreover, they provide a mechanism by which CFs can modulate the simple spike frequency of PCs...
  35. ncbi request reprint Long-term depression at olfactory nerve synapses
    Hiroki Mutoh
    Laboratory for Neuronal Circuit Dynamics, Brain Science Institute, The Institute of Physical and Chemical Research RIKEN, Wako Shi, Saitama 351 0198, Japan
    J Neurosci 25:4252-9. 2005
    ..LTD at the ON--> MC synapse is potentially relevant for the establishment, maintenance, and experience-dependent refinement of odor maps in the olfactory bulb...
  36. ncbi request reprint Transgenic mice expressing a fluorescent in vivo label in a distinct subpopulation of neocortical layer 5 pyramidal cells
    Walther Akemann
    Laboratory for Neuronal Circuit Dynamics, RIKEN Brain Science Institute, Wako Shi, Saitama 351 0198, Japan
    J Comp Neurol 480:72-88. 2004
    ..The in vivo labeled transgenic mice provide an experimental tool for further functional differentiation of these populations of layer 5 pyramidal cells...
  37. ncbi request reprint Motor dysfunction and altered synaptic transmission at the parallel fiber-Purkinje cell synapse in mice lacking potassium channels Kv3.1 and Kv3.3
    Hiroshi Matsukawa
    Laboratory for Neuronal Circuit Dynamics, RIKEN Brain Science Institute, Wako, Japan 351 0198
    J Neurosci 23:7677-84. 2003
    ....
  38. ncbi request reprint Sodium imaging of climbing fiber innervation fields in developing mouse Purkinje cells
    Bibiana Scelfo
    Laboratory for Neuronal Circuit Dynamics, Brain Science Institute, RIKEN, 2 1 Hirosawa, Wako Shi, Saitama 351 0198, Japan
    J Neurophysiol 89:2555-63. 2003
    ....
  39. doi request reprint Imaging brain electric signals with genetically targeted voltage-sensitive fluorescent proteins
    Walther Akemann
    RIKEN Brain Science Institute, Wako City, Saitama, Japan
    Nat Methods 7:643-9. 2010
    ..These protein-based voltage probes will facilitate the analysis of cortical circuits in genetically defined cell populations and are hence a valuable addition to the optogenetic toolbox...
  40. pmc Engineering of a genetically encodable fluorescent voltage sensor exploiting fast Ci-VSP voltage-sensing movements
    Alicia Lundby
    Laboratory for Neuronal Circuit Dynamics, RIKEN Brain Science Institute, Wako City, Saitama, Japan
    PLoS ONE 3:e2514. 2008
    ....
  41. pmc Spectrally-resolved response properties of the three most advanced FRET based fluorescent protein voltage probes
    Hiroki Mutoh
    RIKEN Brain Science Institute, Laboratory for Neuronal Circuit Dynamics, Wako Shi, Japan
    PLoS ONE 4:e4555. 2009
    ..However, each of these fluorescent probes has specific merits when considering different potential applications...
  42. ncbi request reprint Imaging of gene expression during long-term potentiation
    Thomas Behnisch
    Laboratory for Neuronal Circuit Dynamics, Brain Science Institute, RIKEN, 2 1 Hirosawa, Wako Shi, Saitama, 351 0198, Japan
    Neuroreport 15:2039-43. 2004
    ..Application of transcription and translation suppressors and the NMDA receptor antagonist D-AP5 inhibited the L-LTP and prevented the rise in eYFP levels. The early-phase of LTP was not affected by inhibiting protein synthesis...