Restoring vision: therapy and mechanisms of disease

Enabling near-infrared light sensitivity in a blind human retina may supplement or restore visual function in patients with regional retinal degeneration. We induced near-infrared light sensitivity using gold nanorods bound to temperature-sensitive engineered transient receptor potential (TRP) channels. We expressed mammalian or snake TRP channels in light-insensitive retinal cones in a mouse model of retinal degeneration. Near-infrared stimulation increased activity in cones, ganglion cell layer neurons and cortical neurons, and enabled mice to perform a learned, light-driven behavior. We tuned responses to different wavelengths by using nanorods with different lengths, and to different radiant powers by using engineered channels with different temperature thresholds. We targeted TRP channels to human retinas, which allowed the activation of different cell types by near-infrared light, post-mortem.