Toward Better Genetically Encoded Sensors of Membrane Potential. Issue 5 (May 2016) - Storace, Douglas
Abstract : Genetically encoded optical sensors of cell activity are powerful tools that can be targeted to specific cell types. This is especially important in neuroscience because individual brain regions can include a multitude of different cell types. Optical imaging allows for simultaneous recording from numerous neurons or brain regions. Optical signals of membrane potential are useful because membrane potential changes are a direct sign of both synaptic and action potentials. Here we describe recent improvements in the in vitro and in vivo signal size and kinetics of genetically encoded voltage indicators (GEVIs) and discuss their relationship to alternative sensors of neural activity. Trends: Recently developed genetically encoded voltage indicators (GEVIs) have larger and faster fluorescence signals. The new GEVIs result in improved signal-to-noise ratios in in vivo measurements in the mammalian brain. In some instances, GEVI signals are substantially faster and more informative than measurements with genetically encoded calcium indicators (GECIs).