Improved detection of electrical activity with a voltage probe based on a voltage‐sensing phosphatase

•  The use of genetically encoded voltage probes has been expected to enable sensitive detection of spatiotemporal electrical activities in excitable cells. •  However, existing probes suffer from low signal amplitude and/or kinetics too slow to detect fast electrical activity. •  We have developed an improved voltage probe named Mermaid2. •  Mermaid2 provides ratiometric readouts of electrical activity with fast kinetics and great sensitivity, and was able to detect single‐event electrical activity both in vitro and in vivo. •  Mermaid2 will expand our chances to analyse electrical events that have been less accessible by using other techniques.

[1]  Karel Svoboda,et al.  Rapid Redistribution of Synaptic PSD-95 in the Neocortex In Vivo , 2006, PLoS biology.

[2]  A. L. Goldin.  Maintenance of Xenopus laevis and oocyte injection. , 1992, Methods in enzymology.

[3]  Takeharu Nagai,et al.  Direct measurement of protein dynamics inside cells using a rationally designed photoconvertible protein , 2008, Nature Methods.

[4]  J. Ruppersberg.  Ion Channels in Excitable Membranes , 1996 .

[5]  Michael Z. Lin,et al.  Improving FRET dynamic range with bright green and red fluorescent proteins , 2012, Nature Methods.

[6]  Ehud Y Isacoff,et al.  A Genetically Encoded Optical Probe of Membrane Voltage , 1997, Neuron.

[7]  G. Drummond.  Reporting ethical matters in The Journal of Physiology: standards and advice , 2009, The Journal of physiology.

[8]  Masaharu Ogawa,et al.  Gene application with in utero electroporation in mouse embryonic brain , 2008, Development, growth & differentiation.

[9]  Vincent A. Pieribone,et al.  Single Action Potentials and Subthreshold Electrical Events Imaged in Neurons with a Fluorescent Protein Voltage Probe , 2012, Neuron.

[10]  Tetsuichiro Saito.  In vivo electroporation in the embryonic mouse central nervous system , 2006, Nature Protocols.

[11]  James E. Fitzgerald,et al.  Photon shot noise limits on optical detection of neuronal spikes and estimation of spike timing. , 2013, Biophysical journal.

[12]  Ehud Y Isacoff,et al.  Subunit organization and functional transitions in Ci-VSP , 2008, Nature Structural &Molecular Biology.

[13]  Yasushi Okamura,et al.  Improving membrane voltage measurements using FRET with new fluorescent proteins , 2008, Nature Methods.

[14]  Walther Akemann,et al.  Imaging neural circuit dynamics with a voltage-sensitive fluorescent protein. , 2012, Journal of neurophysiology.

[15]  Yasushi Okamura,et al.  Optically detected structural change in the N-terminal region of the voltage-sensor domain. , 2013, Biophysical journal.

[16]  T. Knöpfel,et al.  Design and characterization of a DNA‐encoded, voltage‐sensitive fluorescent protein , 2001, The European journal of neuroscience.

[17]  N. Nakatsuji,et al.  Efficient gene transfer into the embryonic mouse brain using in vivo electroporation. , 2001, Developmental biology.

[18]  R. Ranganathan,et al.  The structural basis for red fluorescence in the tetrameric GFP homolog DsRed , 2000, Nature Structural Biology.

[19]  Yasushi Okamura,et al.  Phosphoinositide phosphatase activity coupled to an intrinsic voltage sensor , 2005, Nature.

[20]  V. Pieribone,et al.  A Fluorescent, Genetically-Encoded Voltage Probe Capable of Resolving Action Potentials , 2012, PloS one.

[21]  E. K. Kosmidis,et al.  Three fluorescent protein voltage sensors exhibit low plasma membrane expression in mammalian cells , 2007, Journal of Neuroscience Methods.

[22]  K. Shibuki,et al.  Transcranial fluorescence imaging of auditory cortical plasticity regulated by acoustic environments in mice , 2006, The European journal of neuroscience.

[23]  Amiram Grinvald,et al.  VSDI: a new era in functional imaging of cortical dynamics , 2004, Nature Reviews Neuroscience.

[24]  D. Maclaurin,et al.  Optical recording of action potentials in mammalian neurons using a microbial rhodopsin , 2011, Nature Methods.

[25]  Walther Akemann,et al.  Engineering and Characterization of an Enhanced Fluorescent Protein Voltage Sensor , 2007, Neuroscience Research.

[26]  Atsushi Miyawaki,et al.  GFP-like proteins stably accumulate in lysosomes. , 2008, Cell structure and function.

[27]  J. Tanaka,et al.  Construction of Epstein-Barr virus-based expression vector containing mini-oriP. , 1999, Biochemical and biophysical research communications.

[28]  Yuichiro Hori,et al.  [Crystal structure of the Aequorea victoria green fluorescent protein]. , 2007, Tanpakushitsu kakusan koso. Protein, nucleic acid, enzyme.

[29]  A Miyawaki,et al.  Directed evolution of green fluorescent protein by a new versatile PCR strategy for site-directed and semi-random mutagenesis. , 2000, Nucleic acids research.

[30]  David Ogden,et al.  Microelectrode techniques : the Plymouth Workshop handbook , 1994 .

[31]  M. Greenberg,et al.  Calcium Influx via the NMDA Receptor Induces Immediate Early Gene Transcription by a MAP Kinase/ERK-Dependent Mechanism , 1996, The Journal of Neuroscience.

[32]  Bradley J. Baker,et al.  Genetically encoded fluorescent voltage sensors using the voltage-sensing domain of Nematostella and Danio phosphatases exhibit fast kinetics , 2012, Journal of Neuroscience Methods.

[33]  M. Kondo,et al.  A high GluR1 : GluR2 expression ratio is correlated with expression of Ca2+‐binding proteins in rat forebrain neurons , 2000, European Journal of Neuroscience.

[34]  Vincent A Pieribone,et al.  A genetically targetable fluorescent probe of channel gating with rapid kinetics. , 2002, Biophysical journal.

[35]  Walther Akemann,et al.  Imaging brain electric signals with genetically targeted voltage-sensitive fluorescent proteins , 2010, Nature Methods.

[36]  Thomas Knöpfel,et al.  Red-shifted voltage-sensitive fluorescent proteins. , 2009, Chemistry & biology.

[37]  Yasushi Okamura,et al.  Visualizing voltage dynamics in zebrafish heart , 2010, The Journal of physiology.