Eliza writes, "A researcher from Lehigh University has invented a light-based pacemaker for fruit flies, and says a human version is 'not impossible.' The pacemaker relies on the new technique of 'optogenetics,' in which light-sensitive proteins are inserted into certain cells, allowing those cells to be activated by pulses of light. Here, the proteins were inserted into cardiac cells so the researchers could trigger the contractions that produce heartbeats."
This isn't the world's first optogenetic pacemaker. The paper notes that research groups have done similar work in zebrafish and mice, two species that are commonly used in scientific experiments. But developing the technique for fruit flies can enable new kinds of research in cardiology, Zhou told IEEE Spectrum in a phone interview. The optical stimulation of zebrafish hearts could only be performed when the fish were at an early development stage, when light could reach the heart through the tissue. And for the mouse study, the scientists had to surgically open the chest wall. "Their approach is exciting, but it's heavily invasive," Zhou says. "You can only do it once."
With the flies, however, Zhou's team could non-invasively stimulate their hearts at all developmental stages: from larva to pupa to adult. Scientists can therefore use this technique in prolonged studies of cause and effect. In flies that are genetically predisposed to have heart attacks, for example, scientists could use the optical pacemaker to regulate a fly's heartbeat in its larval stage, and see what impact that pacing has on the adult fly. "Maybe if you have steady pacing in the larva, you don't have those problems," Zhou says. "That's just a hypothesis—but our technology enables researchers to test it."
[Eliza Strickland/IEEE Spectrum]