Reversibility of Age-Related Memory Loss in Mice

Age-related memory loss has been attributed to the progressive and irreversible attrition of neurons that begins in early adulthood, to the “strength” of the synapses, and more recently, to genes and gene activation patterns in the neurons that subserve memory. Gene activation is the result of multiple complex factors, one of which is alterations of the chromatin protein complex around which DNA is wrapped. In particular, various chemical modifications of histone, one of the chromatin proteins, play a key role in whether a particular region of DNA is transcribed into RNA.

An international team trained mice of different ages to solve various cognitive tests. The oldest mice had the hardest time learning the tasks; compared with young mice, th…