Proteins control wiring of eye to the brain.

• Position: Optics - Nervous system research - Brief Article

A crucial piece of the puzzle of how the eye becomes wired to the brain has been revealed by scientists at the Salk Institute for Biological Studies, La Jolla, Calif., and the University of Texas Southwestern Medical Center at Dallas. Researchers report that a certain class of Eph receptors and ephrin ligands--proteins that cause cells to either repel or attract each other--control how nerve connections from the developing eye form maps that present what people see to visual centers in the brain.

"We knew that a certain class of Ephs, the A-class Ephs, were important in mapping the axons on the left-right, or horizontal, axis of the eye into the brain," explains Dennis O'Leary, professor of molecular neurobiology, Salk Institute, the senior author of the study. "Our new research now identifies how optic axons map the top-bottom, or vertical, axis of the retina into the brain and also defines the biochemical signals used to control this mapping through the analyses of a variety of important mutant mice."

The findings do not have immediate clinical application, but are another important step in understanding how the human nervous system develops and in particular how the...