Scientists have used mouse brains to demonstrate a new neural-optic system to manipulate memories. The technique hinders nerve activity -- known as long-term potentiation or LTP -- which would otherwise consolidate memory during sleep. The research team illuminates mouse brains to inhibit cofilin, a protein essential for LTP. When the specific areas of the brain are irradiated twice, once immediately after the mouse learns a task and then again during sleep after learning, memory is erased.