Feb. 21 (UPI) -- A breakthrough in bone marrow may help slow cognitive decline in people who suffer from Alzheimer's disease, a study says.
After receiving a bone marrow transplant from 4-month-old mice, a group of 18-month-old mice had higher cognitive ability than mice in the same age that didn't receive transplants from younger counterparts, new researched published Thursday in the journal Communications Biology showed.
"While prior studies have shown that introducing blood from young mice can reverse cognitive decline in old mice, it is not well understood how this happens," said Helen Goodridge, a researcher in biomedical sciences at Cedars-Sinai and study co-senior author, in a news release. "Our research suggests one answer lies in specific properties of youthful blood cells."
The older mice that received young marrow showed more connections between synapses, or neurons in the hippocampus, than the older mice that received old marrow transplants or the ones that got none.
That's important because synapses are a key to helping the brain perform well.
The researchers think the synapses in the mice with poor cognitive function may have been deactivated by the immune cell known as microglia. When functioning properly, the cell can support healthy neuron activity. But when microglia goes haywire, it can severe synapses.
The transplantation of the young marrow, the researchers say, deactivated some of the microglia, keeping the synapses connected.
This discovery could help advance the development of an effective treatment for Alzheimer's disease, a condition projected to strike 14 million people by 2060, the Centers for Disease Control and Prevention estimates.
"We are entering an era in which there will be more elderly people in the population, along with an increased incidence of Alzheimer's disease, putting a huge burden on the health system," said Clive Svendsen, director of the Cedars-Sinai Board of Governors Regenerative Medicine Institute and study co-senior author, in a news release. "Our work indicates that cognitive decline in mice can be significantly reduced by simply providing young blood cells, which act on the brain to reduce the loss of synapses related to aging."