Oxford's Gero Miesenböck has written an article in SciAm about the emerging field of optogenetics and his own quest to use genetically encoded sensors and actuators to measure activity of specific neuronal cell populations. Encoding fluorescent proteins into the DNA of neuronal cells was the first step to visualizing specific cellular response, and using light to activate these cells has helped Miesenböck control circuitry in "remote-controlled flies." Some clinical applications of this work include "sensory prosthetics, therapy for movement disorders (as has now become reality with deep-brain stimulation for Parkinson's disease), and regulation of mood and behavior."