Rod and cone photoreceptors capture light and convert it into a neural signal. The molecular basis for this conversion has been well described through experiments carried out over the past several decades. The absorption of light by a photoreceptor cell triggers a series of chemical reactions known as the phototransduction cascade. These reactions amplify the original light absorption event culminating in the hyperpolarization of the photoreceptor. Equally important for vision is the photoreceptor's ability to switch off this signaling cascade in response to darkness. I used biochemical, electrophysiological and genetic methodology to study the chemistry underlying the recovery of photoreceptors to their dark state following a variety of light stimuli in both in vitro and in vivo systems. |