In the brain study, the researchers injected 15-month-old
mice – which is just over half their natural life span – with GDF11 daily for a
month. The volume of the blood vessels in their brain increased by 50 per cent
and the number of brain stem cells by 29 per cent. Both factors are known to
improve brain function.
In a separate study, they gave 18-month-old mice, the equivalent of mid-to-late middle age, eight injections of blood plasma taken from 3-month-old mice. Three weeks later, the brain cells of the older mice had 20 per cent more dendrites, the spines that relay messages between neurons, than mice given a placebo.
The mice performed about 50 per cent better on two standard tests of cognitive function. The studies show the old brain is plastic and can recover function, and that this can be done so simply, just by injecting 'young' blood plasma.