Broadly speaking, the bigger the animal the longer it lives. Based on their mouse-like size, naked mole-rats would be expected to live around three to five years. But their maximum lifespan is over 30 years, and current record holder is a 39-year old. They age healthily too, making it difficult for researchers to tell the difference between a three-year-old and a 30-year-old by eye alone.
“I met a 37-year old naked mole-rat when I was 38,” says Smith. “I had flashes of grey in my hair and wrinkles in my face, but the mole-rat looked great!”
As you get older, your chance of dying increases because more things start going wrong – but naked mole-rats don’t have this age-related risk of death. They usually die because another animal kills them in a fight.
“It’s great that medicine can now help people live longer, but unfortunately we can’t deal very well with ageing-related illnesses like dementia. If we can understand why the naked mole-rats don’t really get these problems, there’s an awful lot to be learned,” he says.
In collaboration with Dr Gabriel Balmus in the University’s Department of Clinical Neurosciences/UK Dementia Research Institute, Smith is trying to discover how the cellular profile of the naked mole-rat brain changes with age, to understand what mechanisms exist to support healthy ageing in the naked mole-rat.