Mice Used in the Experiments. (IMAGE) Proceedings of the National Academy of Sciences Caption Young (15-day-old; left) and aged (15-month-old; right) mice used in the experiments. Credit Kathlyn J. Gan Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.