The study, carried out by the Riken Brain Science Institute in Japan and the Massachusetts Institute of Technology (MIT) in the U.S., used blue light to stimulate the brain cells of mice and was able to restore the lost memories with the help of a protein, according to the article published in the U.S. based journal Science. The blue light caused the activation of the neurons in the brain as previously lost memories are re-formed.

In order to restore the memory, scientists first injected a compound named "anisomisin" to prevent mice to form new memories. The mice were later given an electric shock which made them feel frozen and they were then taken to a new chamber. As the mice experienced amnesia due to the anisomisin injections, they did not recall anything or did not show signs of freezing when they were taken back to the room where they were shocked. However, mice which were not injected with the compound were frightened.

One of the scientists that conducted the research, Susumu Tonegawa said studies have been conducted for decades on amnesia caused by brain trauma, stress and Alzheimer's. Tonegawa, who won Nobel Prize for Medicine in 1987, added that the research indicated that "past memories may not be erased, but could simply be lost and inaccessible for recall."