The blood of young people may hold compounds that benefit the brains of older people with Alzheimer’s disease, so scientists are looking at whether transfusions may help people with the condition. Research in animals has shown that the blood of the young may counter some of the effects of ageing in older brains. For instance, it might help to improve learning and memory, as well as generate new brain cells. Now, scientists want to see if the benefits hold true in people.
Rejuvenating organs?
“The possibility that one or many proteins in young human blood can rejuvenate a diversity of organs (including the brain) is a tantalising one that should spur further research,” Tony Wyss-Coray, a professor of neurology at the Stanford University School of Medicine, and colleagues wrote in the journal JAMA Neurology.
In experiments, researchers connected the blood vessels of young and old mice, so that two animals shared a blood supply. They found that, following an injury, the older mice saw greater improvements in the repair of muscle and bone compared with older mice not connected to younger mice. Later experiments showed that older mice that were exposed to young blood saw an increase in the number of new brain cells in a part of the brain linked with memory.
Improved memory
In addition, a 2014 study found that injecting blood plasma from young mice into older mice for three weeks improved their learning and memory. (Plasma is the liquid portion of blood — it is devoid of blood cells, but contains proteins and other molecules.) In the experiments, the older mice that were given young blood were more easily able to find a hidden platform in a water maze, compared with mice given older blood.
Messengers in blood
Researchers speculated that “messengers” in the blood, such as hormones and growth factors, may be responsible for some of the rejuvenating effects. Young blood contains more of the compounds that are involved in the repair and maintenance of tissues than older blood does, Wyss-Coray said.
“We think when we treat an old organism… with young blood, we give it a boost of these young messengers, and that this recharges the old brain, and possibly other organs, and makes them function like younger ones again,” Wyss-Coray had said in a talk at the World Economic Forum in January. In fact, a protein called CCL11, which is more common in older mice, has been shown to impair memory and brain cell generation when it is given to younger mice. In contrast, a growth factor called GDF11 increases brain cell generation in older mice. Dr Marc L. Gordon, chief of neurology at Zucker Hillside Hospital, New York, said the new article “raises some intriguing questions” but that these ideas “need a lot more research to see if they would bear fruit”.
—Source: www.livescience.com
