Dementia patients have been offered hope that their memory could be repaired after scientists showed that injecting blood from the umbilical cords of human babies restores brain function.
Researchers at Stanford University School of Medicine in the US discovered that cord blood contains an important protein which vanishes as humans get older. It is believed the protein encourages neuroplasticity in the brain, allowing neurons to adapt and communicate more effectively.
When human cord blood was injected into elderly mice they performed far better in learning and memory tests and even started nesting again, gathering up cotton wads to make beds, an instinctive behaviour that is largely forgotten in old age.
"Everyone experiences some decline in memory as they get older. The possibility that this process can be reversed by an infusion of young blood sounds like the stuff of science fiction, but this is what the study is beginning to show," head of research at the UK's Alzheimer's Society, Dr James Pickett, said.
"This study finds that a factor in human umbilical cord blood can enter the brain and restore some of the processes that are essential for forming new memories."
The researchers think the cord blood repairs the hippocampus, a part of the brain which in both mice and humans is critical for converting experiences into long-term memories.
In particular, the hippocampus is essential for helping people remember spatial information, such as how to find your way back to your car or information about autobiographical events, such as what you ate for breakfast.
The new study marks the first demonstration that human blood can aid older mice's memory and learning, which the authors say increases the likelihood that it could have a similar beneficial effect in people.
"It's remarkable something in your blood can influence the way you think," said the study's senior author, Dr Tony Wyss-Coray, PhD, professor of neurology and neurological sciences at Stanford.
The Stanford team had already proved that young blood can reverse some of the signs of ageing in mice but had never shown it could restore learning and memory.
The study was published in the journal 'Nature'.