A TRIO of Australian and American scientists have made a discovery that could radically change the understanding of how the brain repairs itself.
They have shown that other parts of the brain take over to compensate for lost function if there is damage to the hippocampus, a part of the brain responsible for learning and memory.
These parts are often far from the damaged site.
The research could lead to important advances in the treatment of accident and stroke victims, as well as those living with Alzheimer's disease.
"Until now, we've been trying to figure out how to stimulate repair within the hippocampus. Now we can see other structures stepping in, and whole new brain circuits coming into being," said Dr Bryce Vissel from Sydney's Garvan Institute of Medical Research.
"It's truly exciting."
Dr Vissel played a key role in helping to identify the brain pathways and structures involved after two US scientists made a surprising discovery that rats are able to learn new tasks after damage to the hippocampus.
Dr Vissel's team worked with Dr Moriel Zelikowsky and Dr Michael Fanselow to identify the exact regions of the brain that take over.
Their breakthrough is published in the early online edition of the Proceedings of the Academy of Science (PNAS), the journal of the US National Academy of Sciences.
Dr Fanselow says all complex behaviours involve multiple parts of the brain, with one region's message affecting how another region will respond.
"The brain is heavily interconnected."
He says once scientists understand why one pathway is chosen over another, they will be able to encourage pathways to take over when they need to, especially in the case of brain damage.
"I expect the brain probably has to be trained through experience.
"Behaviour creates molecular changes in the brain. We can try to facilitate those changes through behaviour and drug therapy.
"Future treatments are not going to be all behavioural or all pharmacological, but a combination of both," he says.
"It's probable that the brains of Alzheimer's sufferers are already compensating for damage and this discovery has significant potential for extending that compensation," Dr Vissel said.
Originally published as Aussie doctors in brain breakthrough