Brain maps reveal disease pathways

There is no cure for genetically inherited conditions, such as Huntington's disease, that cause the brain to degenerate. Neuroscientist Professor Gary Egan is working to change that. He is leading research to map the progress of these diseases using ultra-powerful imaging equipment, with the aim of developing treatments to slow or prevent the onset of brain degeneration.

Conditions such as Huntington's disease and Friedreich's ataxia are genetically inherited neurodegenerative diseases that affect motor coordination and lead to dementia. Part of the problem, Gary says, is that it can take 20 years before clearly identifiable clinical symptoms appear.

'The enormous frustration for neuroscientists is that while it is possible to identify people who will suffer from these diseases using genetic tests, we need to be able to clearly identify what is happening in the brain very early in the course of the disease in order to test potential cures or treatments.'

Gary leads the Monash Biomedical Imaging team using world-class magnetic resonance imaging (MRI) equipment to map the brain changes in those carrying the genes for such diseases. The maps provide a high level of detail, and at an early stage of the disease, before symptoms manifest. This is providing important information that could help develop preventive treatments and a possible cure.

'If we can map the path of the disease well before it starts to take hold then it may allow us to come up with and track the progress of experimental preventive therapies in the future.'

In one study, Gary and his team are using MRI on people carrying Huntington's disease to map its effect on the brain.

'What we are looking for are bio-markers such as high concentrations of metals associated with neurodegenerative diseases. These bio-markers track the death of brain cells and neural pathways as the disease progresses."

In a parallel study, Gary is planning on using ultra-high resolution X-ray imaging available at the Australian Synchrotron to track changes in the brains of mice that have been implanted with a human gene carrying a neurodegenerative disease. Gary says commonalities between the mouse brain and the human brain - especially in the motor function areas that relate to Huntington's disease - make this investigation invaluable.

'As the disease develops in the brain of a mouse it manifests very similar symptoms as it would in a human brain. But because we are able to use ultra-high strength imaging, we can look at cellular changes at a microscopic level allowing far higher resolution than would be possible in human studies.'

This understanding of the progress of the disease in the animal model can then be translated into an understanding of the human brain. Using this same technology, Gary and his team are also tracking the effect on the mice of experimental drugs that are aimed at halting the progress of the disease.

'If those drugs are shown to work, we may be able to initiate early clinical trials on human beings.'