optogenetics Holds Promise across the Body

Optogenetics is a method to control neurons using light that is revolutionizing neuroscience. The method involves genetically changing the particular cell types to make them produce light-sensitive proteins. Later scientists can activate the cells using light pulses delivered to the brain via fibre-optic cable.

This has already given researchers the ability to probe the circuitry underlying animal brain functions. Some have moved beyond the brain, working toward human medical applications. Optogenetics provide a flexible approach to treating and possibly curing blindness.The retina’s photoreceptor cells use light-sensitive proteins, called opsins, to convert light entering the eye into electrical signals. In case the cells fail, researchers can use viruses to deliver opsin-producing genes to targeted cells to restore light sensitivity to photoreceptors or to make other cell types in the retina sensitive to light.

This treats blindness with many different causes and levels of retinal degeneration. This method works in the laboratory, and multiple clinical trials of such systems in people are already underway. Sometimes this setup uses cameras and special goggles to project light wavelengths and intensity optimized for the opsin being used, but scientists are also testing opsins that respond to direct light.A team led by bioengineer Martin Fussenegger of ETH Zürich is Optogenetics manipulating gene expression to regulate blood glucose levels in diabetic mice. In a study, the team engineered cells to respond to blue light by expressing a protein known to modulate blood glucose. Fussenegger said that there was a direct link between light and gene expression.

The group’s experiments showed increased insulin levels and reduced glucose sensitivity in mice that were implanted with the engineered cells and then treated with light. In 2017 the bioengineer and his colleagues described implanting wirelessly powered LEDs along with the engineered cells to create a smartphone-controlled semi-automatic system. They have continued refining the technique.