QIMR Berghofer scientists, in collaboration with colleagues at UNSW, have comprehensively mapped the connections in the healthy elderly brain, known as a connectome – laying the groundwork for new research into Alzheimer’s disease and dementia.
The Elderly Connectome project also found new evidence of a neural basis for the different behaviour of men and women and that the gender differences in brain networks continue through to old age.
Lead investigator Alistair Perry from QIMR Berghofer’s Systems Neuroscience group said the connnectome of the elderly brain is organised in a very similar way to that of a young adult, but its capacity to transfer information is slightly hindered.
“The length of fibre connections is significantly shorter in the elderly brain, and the major ‘highways’ carry less information than the younger adult brain,” Mr Perry said.
“We believe this relates to the cognitive decline in some elderly people in areas such as memory, attention and processing complex tasks.
“Now we know how healthy ageing looks, we can identify the changes caused by neurodegenerative disease, and ways we might be able to intervene.”
Mr Perry said the next step would be to use the same methods to map the connectome of those with mild cognitive impairment.
“One in five people with mild cognitive impairment go on to develop Alzheimer’s and this will identify the connections that break down at the early phase of the disease,” he said.
“We would then be able to predict with greater accuracy if someone is at increased risk of Alzheimer’s, and could develop new approaches to treatments.”
Mr Perry said the team was keen to tackle neurodegenerative diseases because of their terrible cost to families and society, but further research would be dependent on securing more funding.
The scientists used the latest imaging technology in conjunction with sophisticated computer models to create the complex connectome map.
QIMR Berghofer researchers collaborated with the University of NSW Centre for Healthy Brain Ageing (CHeBA) and examined scans and data from the Sydney Memory and Ageing Study (MAS).
Beginning in 2005, the MAS study examines over time the rate of cognitive decline in older individuals whose health is “better than average”.
Mr Perry said the study provided additional evidence of a neural basis for different behaviour in men and women.
“We have also shown that those differences between men and women continue through into later life, with the study plotting the connections of 74 to 95 year olds,” he said.
“In elderly women we found stronger networks around verbal and language areas of the brain.
“In men there was not such a clear distinction but we found greater connections to the regions of the brain related to reward centres and behaviour regulation.”
The study also compared the connectome of elderly females with young females.
“We found there was not much actual change in the organisation of the brain from a 20 year old to an 80 year old.”
The study was funded by the NHMRC and ARC and has been published in NeuroImage: http://www.sciencedirect.com/science/article/pii/S1053811915002888