[1] It is a promising optogenetic recording tool that enables exporting electrophysiological signals from cultured cells, live animals, and ultimately human brain.
The first GEVI, coined FlaSh,[9] was constructed by fusing a modified green fluorescent protein with a voltage-sensitive K+ channel (Shaker).
Conceptually, the structure of a GEVI should permit the function of sensing the voltage difference and reporting it by change in fluorescence.
A majority of GEVIs are based on the Ciona intestinalis voltage sensitive phosphatase (Ci-VSP or Ci-VSD (domain)), which was discovered in 2005 from the genomic survey of the organism.
[33] Researchers have used it to probe neural communications of an intact brain (of Drosophila[45] or mouse[46]), electrical spiking of bacteria (E. coli[22]), and human stem-cell derived cardiomyocyte.