Optogenetics, a field largely pioneered by Stanford scientist Karl Deisseroth, MD, PhD, has offered new insights into diagnosing and treating neurological conditions such as depression, Parkinson's disease and Alzheimer's. Now researchers are beginning to experiment with the technology, which turns select cells on or off with flashes of light, beyond the brain to cardiovascular applications. Technology Review reports:
A recent study in Circulation: Arrhythmia & Electrophysiology showed how modified cells that respond to low-energy blue light can be used to stimulate heart tissue to beat. The researchers say this represents a first step toward a new, more efficient and precise kind of pacemaker. Light-sensitive cells could serve as a conductor of the heart's rhythm, creating a biological pacemaker generated from the patient's own cells.
One of the obstacles in using optogenetics as a clinical tool is the need to introduce genes into cells. To get around the problem, the researchers in the current study, led by Emilia Entcheva, a bioengineer at SUNY Stony Brook, decided to take advantages of the tight communication between heart-muscle cells. These cells beat synchronously because they are coupled to one another through cell junctions.
Rather than having to modify every cell in the heart to respond to light, Entcheva says, it's possible to inject a small population of light-sensitive donor cells, and allow those cells to couple with, and orchestrate, the beating of the normal tissue.
The researchers' findings (subscription required) show that the hybrid cell population contracted in waves that matched the electrical pulses when stimulated by light.
Previously: Nature Methods names optogenetics its "Method of the Year" , Using light to get muscles moving, Karl Deisseroth outlines optogenetics in Scientific American and Using light to better understand mental illness