This was a crucial proof of concept. But turning optogenetics into an effective therapy demanded refinements. Key among them was to work out which cells should be made light-sensitive.

In recent years, at least two companies have announced the start of clinical trials to test optogenetics-based therapies in humans, and one of them recently announced that patients who were blind or ...

These include electrophysiology, the recording of neural activity with electrodes, and optogenetics ... a certain kind of ...