When the optical fiber connected to the mouse's brain emits light, it moves as desired. This is because the nerve cells react to the light. Karl Deisseroth, a 54-year-old professor at Stanford University in the United States, developed the technology of optogenetics in 2005 to control nerve cells with light.

Professor Deisseroth noted at a press conference held at the Westin Chosun Hotel in Jung-gu, Seoul, on the 18th that "we are entering an era where brain diseases can be treated using optogenetics," adding that "as we can directly control nerve cells, it will become a more powerful therapeutic tool than Elon Musk's Neuralink."

He was recognized for his contribution to understanding the role of cells in human cognition and behavior through optogenetics and finding the connection between the brain and behavior, receiving the 18th Asan Medical Award. He also received a prize of $250,000 (approximately 360 million won).

Cal Dysorothos, a professor at Stanford University in the U.S., meets with reporters at the Westin Chosun Hotel in Jung-gu, Seoul, on Nov. 18, stating, “The optogenetics technology that enables direct control of neurons will be a more powerful tool for treating neurological diseases than Neuralink.” /Courtesy of Asan Social Welfare Foundation

Professor Deisseroth drew ideas for optogenetics from a protein called opsin that reacts to light found in green algae living in the ocean. He inserted the gene that produces this protein into the nerve cells of animals. The gene delivery was done by a harmless virus in the body. The opsin synthesized by the gene entering the animal cell responded to light, opening and closing the nerve's cell membrane. This controls the nerve cells. Professor Deisseroth stated that similarly controlling nerve cells with light could conquer intractable neurological diseases.

He compared optogenetics to Neuralink, a corporation focused on brain-computer interfaces (BCI). This company measures neural signals by connecting electrodes to the brain, reading patients' thoughts and operating computers or robots accordingly. Professor Deisseroth explained that "while Neuralink can read or observe neural signals, there are limitations to treating diseases. In contrast, optogenetics can fundamentally change functionality by directly manipulating nerve cells, making it the most suitable technology for treating neurological and psychiatric disorders."

Professor Deisseroth introduced a clinical trial that restored vision to a visually impaired person as a notable case. An international joint research team, including researchers from the United States, Switzerland, and the United Kingdom, announced in 2021 in the international journal Nature Medicine that they treated a patient with retinitis pigmentosa using optogenetic technology. Retinitis pigmentosa is a neurological disease characterized by the deterioration of photoreceptors that detect light in the retina.

One patient who participated in that experiment had been diagnosed with retinitis pigmentosa 40 years ago and could not see at all, but after receiving an artificial retina created using optogenetics, they successfully recognized objects in front of them and found their exact location. Professor Deisseroth mentioned, "For diseases like retinitis pigmentosa, where the cause is already known, optogenetics can become a powerful tool," adding, "I expect that as research on the brain progresses, the number of diseases that can be treated with optogenetics will increase. "

A scene of implanting optical fibers into a mouse's brain to conduct optogenetics experiments. Optogenetics is a technology that uses light to control nerve cells (neurons). /Courtesy of Cell

Research is also being attempted for drug development using optogenetics. This method verifies the operational state of nerve cells while shining light and examines the drug's effects. Professor Deisseroth has founded a biotechnology corporation called Maplight Therapeutics and is challenging drug development. Maplight Therapeutics is currently conducting Phase 2 clinical trials of a newly developed drug utilizing the optogenetic platform.

He cited Alzheimer's disease treatments as an example. Currently, there is an issue that the sedative effect is too strong and there are significant side effects. Since the exact nerve cells causing Alzheimer's disease are not known, it is like indiscriminately bombing. Professor Deisseroth stated, "If we develop drugs that act only on specific nerve cells using optogenetics, we can effectively alleviate dementia symptoms caused by Alzheimer's disease."

This means that personalized targeted treatments can be provided. Professor Deisseroth also announced research results indicating that optogenetics can control not only nerve cells but also heart muscles. He said, "I believe optogenetics can provide solutions for various diseases."

Professor Deisseroth has developed new technologies for studying the brain one after another. In 2013, he developed the 'tissue transparency' technology with Dr. Jung Kwang-hoon (currently a professor at the Massachusetts Institute of Technology). This occurs because the brain is opaque due to the fat that forms cell membranes blocking light. He removed the fat and replaced it with a hydrogel-like substance, allowing visibility of the proteins and DNA that make up nerve cells. This technology makes biological tissues transparent, enabling deep observation without cutting them, and many derivative studies have been published since his research.

Cal Dysorothos, a professor at Stanford University in the U.S., develops tissue transparency technology. Although Professor Dysorothos pioneered optogenetics, he is always challenging new fields of research. /Courtesy of Stanford University

When asked why he continues to challenge new research, having built a reputation to the point of being mentioned as a Nobel Prize candidate due to his research in optogenetics, he replied, "As a scientist, one should not settle for safe research and should not hesitate to engage in risky and challenging research."

He mentioned that he gives similar advice to his students. Professor Deisseroth said, "Even if one is not an engineer or a technician, I advise them to dedicate at least a quarter of their research time to developing new technologies," adding, "Simply doing research differently from others creates opportunities for new discoveries, and this applies equally to all scientists."