Scientists have discovered that the buildup of the beta-2-microglobulin (B2M) protein in the blood and the brain causes age-related memory impairment, according to research published in Nature Medicine.
Blocking the buildup of this protein may slow down or even prevent age-related memory deterioration.
Although many protein levels fluctuate with age, the researchers found evidence in other studies that linked B2M levels to age-related disorders. To see how B2M affected memory, the researchers injected young mice with the protein before having them perform various tasks.
In the first task, the mice had to find a platform that was hidden just below the surface in a water maze. Over the trials, the control mice made only one or two mistakes, while the mice injected with B2M made an average of five. The effect was even more pronounced when B2M was injected directly in the mice’s brains.
In the next task, the researchers put the mice in a chamber and gave them a small electric shock after two minutes. The next day, the mice were returned to the chamber. The control mice, recognizing their environment, froze approximately 50% to 60% of the time in the first minute. The B2M mice only froze 25% to 30% of the time, suggesting the protein impaired their memories of the electric shock.
The researchers also studied mice that had been genetically modified to not produce B2M. Young mice with no B2M did not seem different from controls, but as they aged, the B2M mice’s memories did not decline as quickly as the control mice.
The researchers found that B2M works in conjunction with the MHC1 protein complex. “If we block the interaction between B2M and MHC1, could that either prevent memory loss with old age, if we take it when we are younger? Could it reverse memory loss if we start when we are old?” researcher Saul Villeda, PhD, of the University of California, San Francisco, said in a statement. “Perhaps we can just get rid of it in old people’s blood.”
Understanding Alzheimer’s Disease
Alzheimer disease is an irreversible, progressive brain disease that slowly destroys memory and thinking skills, and eventually even the ability to carry out the simplest tasks, according to the National Institute on Aging. In most people with Alzheimer’s, symptoms first…
Researchers may have found a way to slow down or prevent memory problems that arise in old age and which can become devastating in patients with dementia.
The fresh hope comes from a series of studies in humans and mice that identified a protein which causes memory impairment when it builds up in the blood and brain with age.
Scientists found that injections of the protein made young animals’ memories worse and reduced the growth of new neurons in their brains. Further studies showed that blocking the protein prevented memory loss in older animals, making them smarter than untreated animals of the same age.