Laser light rewrites memories in mice

Nerve cells in the hippocampus help the brain modify recollections

ALTERED   Mice’s bad memories turned into good ones and vice versa with a flash of light. The switch occurred when nerve cells (red) storing the memory were activated while a mouse experienced something new. The black region (center) shows the location of the light-delivering optical fiber.

R. Redondo

With a burst of light, scientists can change good mouse memories into bad ones, and bad ones into good.