Optogenetics, a technique which involves the use of light to control neurons, has been successfully used in mice to restore stability between excitation and inhibition, dampening symptoms of autism. During this process, researchers first engineer the mice to express light-sensitive proteins, known as opsins and then shine a specific type of light into their brains, which has the ability to turn neurons on or off. This technique gives more insight into the cause of autism, showing potentially that changing the ratio of excitation to inhibition improves autistic-like behavior. 

Karl Deisseroth, the lead investigator into this study, believes that this system could be used to ease signs of anxiety, depression and obsessive-compulsive disorder in mice. And while they believe this technique is a long way away from being used in humans, researchers believe this research will open the door to understanding what brain cells and circuits future treatments can target.