bReaCh-ES: An optogenetic tool for stimulating neurons with red light

Researchers in Dr. Karl Deisseroth's lab have engineered a channelrhodopsin variant that can be stimulated by red light and has fast stimulation frequencies. In neurons, channelrhodopsins are light activated protein channels that induce action potential firing. Action potentials are the fundamental signal used by neurons to process sensory inputs and induce behavioral responses. As such channelrhodopsins have become a powerful tool to manipulate neuronal activity by light. The inventors have created a channelrhodopsin variant knows as bReaCh-ES. It can be stimulated by red light (wavelengths beyond 600nm) and reliably evokes action potentials at frequencies of up to 20 Hz. The bReaCh-ES tool can be used to interrogate functional connections between neurons of different brain areas or within local neuronal microcircuits.

Stage of research
The inventors have used bReaCh-ES in behavioral experiments in combination with GCaMP (a fluorescent sensor that allows for optical readouts of neuronal activity) for in vitro and in vivo imaging.