He joins a select group of past winners including Nobel laureates Robin Warren and Barry Marshall, bionic ear developer Graeme Clark and cervical cancer vaccine co-inventor Ian Frazer.
Like most big scientific awards, the honour recognises a lifetime’s work rather than a single eureka moment. Professor Bartlett spent decades challenging the “dogma” that the adult brain cannot regenerate.
“We all grew up thinking the brain was a fairly immutable organ that certainly didn’t have any capability of making new nerve cells. The discovery we made 25 years ago — that there were (stem) cells in the brains of adult mice capable of making nerve cells — overturned all that.”
Professor Bartlett and his team went on to discover that adult humans have stem cells in the hippocampi, the seahorse-shaped brain regions that help control memory and spatial awareness, but these stem cells become inactive in older people. Hippocampal functions are among the first to decline in dementia sufferers.
More recent experiments on mice showed that the new nerve cells produced by these stem cells were crucial to properly functioning hippocampi. But exercise helped restore these mechanisms, rebooting the stalled stem cells through molecular mechanisms the team is still exploring.
Now Professor Bartlett is ready to apply this learning to humans, in treadmill studies due to start early next year. “The biggest question ever asked of me is, what is the right amount of exercise?
“There seems to be a sweet spot with exercise. If you exercise these animals too little or too long, it doesn’t work. These upcoming trials are about defining the sweet spot in humans, and using that (information) in a cohort of cognitively impaired older people.”