In an accidental discovery, researchers appear to have slowed the ageing process in the brains of laboratory mice, using ultrasounds or sound wave therapy.

Dr Robert Hatch, from the University of Queensland, said scientists had used the technique to stop the normal reduction in the structure of brain cells in the hippocampus — an important area for learning and memory — and were now envisioning a future where people could get their brains tuned up like a car.

However, he said the result had initially been a surprising one to the team of researchers.

"We didn't actually envision that this would have the effect it has," he said.

"I still remember I was doing some data analysis on Thursday night and said 'this can't be right' — and it was."

Dr Hatch said they had been continuing on the same thread as last year's research, where the team had discovered ultrasounds could be used to reverse Alzheimer's in mice.

The team of researchers had expected to confirm the therapy would not damage a healthy brain, which they did.

But then realised they had found something else — a way to slow down the brains ageing process.

"What we found is that by applying the ultrasound to these mice you could slow down or stop the change in the structure of these cells as the animals age."

The University of Queensland research was published today in the Public Library of Science online journal, PLOS One.

Finding a way to keep the brain 'forever young'

The team will now examine whether their findings could help stop the brain from declining in learning and memory as people age.

"Our idea is that if you can keep the structure of the brain in a young state, then we should be able to keep the function," he said.

"So we're currently actually testing that exact idea right now."

Dr Hatch said the ultrasound worked by activating cells in the brain which were the "immune cells".

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"And you can activate them to help clear out toxic proteins, and our idea is that it's basically helping these cells maintain the brain in a more healthy state."

Dr Hatch said if they could understand how the brain changed normally, that would help them to work out what to do when something went wrong, and dementia or Alzheimer's developed.

"We then know, 'ok how do we change what's happening to take it back to a more normal situation?'," he said.

"What we're envisioning at some point down the track is — once it's gone through treatments and approvals and everything — we envision that this would be like a check up for your car.