photoreceptor cells

Study shows how eye cells die when exposed to lead

A new study designed to find out why cells in the eye die when exposed to lead may provide novel therapies for retinal damage caused by injury or diseases such as diabetes and retinitis pigmentosa.
The study, published in the Feb. 4 issue of the Proceedings of the National Academy of Sciences, focused on identifying how low-level lead exposure during development in mice injures and eventually kills rod-shaped photoreceptor cells, or rods, in the eye. Rods are cells in the eye that help humans see in dim light. The other type of photoreceptors, or light-gathering cells, called cones are responsible for color and spatial vision. Cones are used primarily in daylight and for activities such as reading.

Researchers Identify Key Pathway in the Pupil’s Response to Light

Medical investigators have demonstrated that a particular protein is important for the eye’s pupil to respond to light. The discovery may help scientists learn more about the eye’s role in non-visual functions such as the synchronization of the body’s internal, circadian clock. Reporting in the Jan. 10 issue of the journal Science, the researchers say that mice that lack the two main types of photoreceptor cells in the retina ? rods and cones ? as well as proteins in the retina called cryptochromes, lose about 99 percent of their sensitivity to light.