New optogenetics technology allows scientists to remotely control specific neurons with blue light. A team from the Institute for Basic Research has developed the genetically encoded, photoactive tropomyosin-related kinase (Trk) technology, called OptoTrk. This allows precise control of receptor tyrosine kinases (RTK) — a group of cell surface receptors that are key to regulating cellular processes. “We have found that OptoTrk can be regulated by simply switching light on and off,” said Dr. Won Do Heo, an associate professor of biological sciences at KAIST University, who led the research. “We were able to control the functional duration of downstream signaling by adjusting the frequency of blue light illumination.” This new technology requires only light to activate the brain’s neuronal functions, without the need for other substances. Specifically, exposure to blue light activates the receptors, subsequently inducing both neuronal growth and differentiation by upregulating the downstream cell signaling. “This newly developed technology will play a groundbreaking role in investigating the functions of neurons in the brain, specifically those functions in the most complicated of neural networks, which existing technologies have limitations exploring,” Heo said. Traditional methods rely on natural ligands or agonists to control such receptor activity. However, those methods do not allow spatiotemporal control, thus requiring extra time to bind to the receptor. This creates limits for researchers studying the dynamic nature of intracellular signaling networks. The new light-controlled receptors are “expected to create experimental opportunities to spatiotemporally manipulate many biological processes both in vitro and in vivo,” the researchers wrote. The research was published in Nature Communications (doi: 10.1038/ncomms5057). For more information, visit www.ibs.re.kr.