Major cause of age-related memory loss discovered

Scientists say they have discovered a protein deficiency in the brain that is a major cause of age-related memory loss, according to a study published online in the journal Science Translational Medicine.

The researchers, from Columbia University Medical Center (CUMC), say this discovery offers the "strongest causal evidence" that age-related memory loss and Alzheimer's disease are individual recognizable conditions.

The study, conducted on postmortem human brain cells and in mice, revealed that the hippocampus in the brain - a region that plays an important part in memory, lacks a protein called RbAp48 in those who experience age-related memory loss.

The finding suggests that a deficiency of this protein is a cause of memory loss, but more importantly, the researchers say this form of memory loss is reversible.

They began conducting this current study in order to seek direct evidence that Alzheimer's disease is a completely separate condition from age-related memory loss.

Previous research has suggested that Alzheimer's disease hinders a person's memory by affecting the entorhinal cortex (EC) in the brain. The EC is a region that provides important pathways to the hippocampus.

According to the study authors, it was thought that age-related memory loss was an early sign of Alzheimer's, but they add that recent evidence suggests age-related memory loss is a separate process that affects the dentate gyrus (DG). This is a subregion in the hippocampus that has direct input from the EC.