Aging is associated with a progressive decline in cognitive function, and slower regeneration of message-relaying neurons in the brain. A protein molecule, called B2M, that accumulates in the blood with age may be linked to cognitive decline, revealed scientists who mooted hopes of a memory-restoring treatment. They observed that the protein was found in higher concentrations in the blood and cerebral spinal fluid of aging humans. Also in mice, inhibiting B2M improved learning and memory in laboratory experiments.Study co-author Saul Villeda of the University of California San Francisco said, "We are very excited about the findings because it indicates that there are two ways to potentially reverse age-related cognitive impairments. One is to introduce pro-youthful blood factors and the other is to therapeutically target pro-aging factors like B2M."