Monday, December 19, 2011

Need an extra eye?

A natural bioelectrical current jumpstarts normal eye development in frogs, researchers have discovered—suggesting a new route toward repairing damaged or diseased eyes.

Almost all cell membranes have "ion channels" that let charged particles move in and out—the essence of an electrical current. But the first clue that bioelectricity might be critical to eyes came a decade ago when Michael Levin at Tufts University in Medford, Massachusetts, and his colleagues altered the number of ion channels in cells in different parts of a frog embryo and found that lens and retinal tissue formed outside the head. Later work by others showed that cells destined to become eyes had an excessive negative charge.

Levin's team has now verified that these pre-eye cells were hyperpolarized, produced DNA regulatory proteins important for eye formation, and did become a lens and retina. Modifying the function of ion channels in four-cell frog embryos led to eyes in the tail and on the gut, but only where cells experienced a particular voltage range, the researchers reported this week in Development. "Bioelectrical information is both necessary and sufficient for inducing development of the vertebrate eye," comments James Coffman, a developmental biologist at the Mount Desert Island Biological Laboratory in Salisbury Cove, Maine.

Read the full article My, Your Eyes Are So Electric.