Optogenetics: A cool tool may have found medical use

Optogenetics is a biological technique that uses light to control neurons that have been genetically modified to express light-sensitive ion channels.  As such, it is a neuromodulation method that controls the activities of individual neurons in living tissue — even within freely-moving animals.  First developed in the mid-2000, optogenetics has furthered the fundamental scientific understanding of how specific cell types contribute to the function of biological tissues including neural circuits. In mouse models, optogenetics has provided insight into Parkinson’s disease and other neurological disorders.  Recently, an international team reported the first successful application of optogenetic therapy in humans: restoring partial eyesight in a blind person with the neurodegenerative disease retinitis pigmentosa. In this patient, intraocular injection of an adeno-associated viral vector encoding ChrimsonR was combined with light stimulation via engineered goggles. The goggles detect local changes in light intensity and project corresponding light pulses onto the retina in real time to activate optogenetically transduced retinal ganglion cells. The patient perceived, located, counted and touched different objects using the vector-treated eye alone while wearing the goggles. In contrast, patient could not visually detect any objects before injection with or without the goggles or after injection without the goggles. Read the original report in Nature Medicine and excellent reporting by Carl Zimmer in the NYT.