Hopping Mice may hold key to appetite regulation

Deakin University researchers believe a tiny mouse found in the deserts of central and western Australia may hold valuable clues to the way appetite is regulated.

Working with colleagues from the University of Tokyo, the researchers have found that the Spinifex Hopping Mouse can regulate its appetite to an extraordinary degree, making it the ideal animal to study in trying to better understand appetite control in people.

Associate Professor John Donald has been studying the appetite of Hopping Mice for three years.

"I am interested in their ability to survive without drinking water for their entire lives if they need to," Associate Professor Donald said.

"Despite being able to survive without drinking water, they still need to be in water balance and we are looking at the mechanisms by which they do this.

"When Hopping Mice metabolise their food they generate metabolic water – 90 per cent of their water comes from the metabolism of their food,'' he said.

The Deakin researchers and their colleagues have been studying the Hopping Mice to see what happens to their appetite in situations when drinking water is not available.

They found that at first the Hopping Mice, to conserve body water, would eat very little for around six days – their appetite effectively became suppressed. After this, their appetite increased markedly to above normal levels.

"It is a natural model of appetite suppression and stimulation," Associate Professor Donald explained.

"For the first six days without drinking water their appetite is suppressed and they consume their body fat. Their appetite then increases and they generate metabolic water by eating a lot."

Associate Professor Donald said the findings potentially represented a new approach to understanding appetite regulation.

"The process of understanding appetite regulation is quite complex and has implications for a wide range of health issues affecting people.

"Through studying the appetite regulation mechanisms of Hopping Mice we are gaining valuable insights into this complex process," he said.