Susumu Tonegawa, a 76-year-old neuroscientist at the Massachusetts Institute of Technology, has discovered a way to reverse symptoms of depression in male mice by reactivating happy memories using a stream of blue light directly on their brains.
First, Tonegawa inserts a light-sensitive gene into a cluster of happy-memory cells that recall their sexual escapades from a few days earlier. When he shines the light, happy feelings return and their depression vanishes.
This approach, which manipulates physiological circumstances, has the potential of becoming a potent new tool in treating depression. And could revolutionize 21st-century psychiatry.