SWITCHES FOR THE BODY ELECTRIC
CARMEN DRAHL · Chemical & Engineering News · 2008
ONE LITTLE BOND —the double bond—is beginning to make a big difference in neuroscience. Under the right chemical circumstances, double-bonded compounds can respond to light by converting between trans and cis isomers. Research teams can now harness these chemical shapeshifters to generate nerve impulses in worms, fish, and rats at will, with the help of a beam of light. Although the technology is in its infancy, the groundwork could lead to a better understanding of, and new treatments for, conditions such as spinal cord injury, Parkinson’s disease, and vision loss. Normally, nerve impulses are produced by voltage-gated ion channels, pores that sense changes in local charge distribution across nerve cell membranes. They open and close, ushering ions into and out of cells to propagate electrical signals. But the new light-based tools create torrents of ions in other ways. Some researchers shuttle ions by means of natural proteins gated by light-activated double-bond latches. Meanwhile, one team ...