RRC ID 47679
Author Ohkura M, Sasaki T, Sadakari J, Gengyo-Ando K, Kagawa-Nagamura Y, Kobayashi C, Ikegaya Y, Nakai J.
Title Genetically encoded green fluorescent Ca2+ indicators with improved detectability for neuronal Ca2+ signals.
Journal PLoS One
Abstract Imaging the activities of individual neurons with genetically encoded Ca(2+) indicators (GECIs) is a promising method for understanding neuronal network functions. Here, we report GECIs with improved neuronal Ca(2+) signal detectability, termed G-CaMP6 and G-CaMP8. Compared to a series of existing G-CaMPs, G-CaMP6 showed fairly high sensitivity and rapid kinetics, both of which are suitable properties for detecting subtle and fast neuronal activities. G-CaMP8 showed a greater signal (F(max)/F(min) = 38) than G-CaMP6 and demonstrated kinetics similar to those of G-CaMP6. Both GECIs could detect individual spikes from pyramidal neurons of cultured hippocampal slices or acute cortical slices with 100% detection rates, demonstrating their superior performance to existing GECIs. Because G-CaMP6 showed a higher sensitivity and brighter baseline fluorescence than G-CaMP8 in a cellular environment, we applied G-CaMP6 for Ca(2+) imaging of dendritic spines, the putative postsynaptic sites. By expressing a G-CaMP6-actin fusion protein for the spines in hippocampal CA3 pyramidal neurons and electrically stimulating the granule cells of the dentate gyrus, which innervate CA3 pyramidal neurons, we found that sub-threshold stimulation triggered small Ca(2+) responses in a limited number of spines with a low response rate in active spines, whereas supra-threshold stimulation triggered large fluorescence responses in virtually all of the spines with a 100% activity rate.
Volume 7(12)
Pages e51286
Published 2012-1-1
DOI 10.1371/journal.pone.0051286
PII PONE-D-12-27822
PMID 23240011
PMC PMC3519846
MeSH Animals Calcium* / chemistry Calcium* / isolation & purification Calcium* / metabolism Calcium Signaling / genetics* Cells, Cultured Dendritic Spines / metabolism Dentate Gyrus / cytology Dentate Gyrus / metabolism Green Fluorescent Proteins* / chemistry Green Fluorescent Proteins* / genetics HeLa Cells Humans Indicators and Reagents / analysis Indicators and Reagents / metabolism Neuroanatomical Tract-Tracing Techniques Neurons / cytology Neurons / metabolism Pyramidal Cells* / cytology Pyramidal Cells* / metabolism Rats
IF 2.74
Times Cited 104
DNA material G-CaMP6 (RDB14609) G-CaMP7 (RDB14610) G-CaMP8 (RDB14611).