Neuroscientists have long sought tools that allow optical imaging of individual neurons' membrane voltage dynamics in awake behaving animals. In a study that originated from Professor Mark Schnitzer's Lab where lead author Yiyang Gong was a postdoctoral fellow, Gong et al.genetically engineered a protein voltage indicator that can report action potentials with <1-ms precision and orders of magnitude lower spike detection error rates than were previously possible. They were thus able to record action potentials and membrane voltage dynamics in the brains of awake mice and fruit flies