Alzheimer's 'lost' memories could be recovered, study says

Professor says research on mice is 'proof of concept'

The lost memories of people with Alzheimer’s may be retrievable, according to scientists who claim they were able to reverse memory loss in animals.

Researchers from the Massachusetts Institute of Technology (MIT) and the Riken Institute in Japan report that they were able to restore lost memories in mice using flashing lights.

The mice, which were genetically engineered to display Alzheimer’s-like symptoms, were placed in cages and given mild electric shocks to their feet.

This causes healthy mice to respond with fear if they are put back into the cage, but the genetically modified animals appeared to have forgotten the experience and showed no fear when placed in cages again.

Patients with Alzheimer’s will display shrinkage in the hippocampus region of their brain, which plays a part in the formulation of memories.

Researchers used flashes of blue light to stimulate cells in the hippocampus region, encouraging the growth of neural pathways in this area of brain. 

Following light stimulation, the mice that had displayed evidence of 'lost' memories began to show fear when placed in the cage – indicating the memories had returned.

Professor Susumu Tonegawa, who led the research, told The Times: “Even if a memory seems to be gone, it is still there. It’s just a matter of how to retrieve it.”

The method of stimulation used is invasive and cannot safely be used in humans, but Professor Tonewaga says the research is “proof of concept” and indicates that supposedly ‘lost’ memories in Alzheimer’s patients may be recoverable if a safe treatment can be developed.

The Alzheimer's society estimates 850,000 people in the UK live with Alzheimer's and dementia, and no cure has been found.