11 Dec 2017
HEIDI DOUGLASS | firstname.lastname@example.org
Established by CHeBA staff in 2007, the Older Australian Twin Study (OATS) is the largest and longest running Australian research study of its kind investigating healthy brain ageing. By studying older twins (aged 65+ years) over time, OATS allows researchers to investigate the complex interactions between multiple genetic and environmental factors which cause brain diseases. Over the last decade, OATS has generated over 32 published papers and contributed to 8 international consortia, providing valuable insights into healthy brain ageing and age-related disease both in Australia and world-wide.
In 2017, data collected by the OATS team has contributed to international research investigating the influence of genes and lifestyle factors on an important brain structure, the hippocampus. The hippocampus is a small brain region that plays a significant role in memory, particularly long-term memory, and in navigation. Both of these abilities are important in being able to engage actively in life. A study analysing genetic and MRI data from 33,536 individuals, including OATS participants, identified four genes that influence hippocampal volume, which plays an important protective factor for memory function and neuropsychiatric disorders such as depression. Three of the genes are known to influence movement of neuronal cells within the brain, which may play a significant role in determining hippocampal volume.
In another study, analysis of data from OATS and four other international twin studies demonstrated that genetic factors account for only approximately 20% of the variability in hippocampal volume changes in adults. As a result, modifiable lifestyle and environmental factors play a large role in determining changes in hippocampal volume. Exercise is one important lifestyle factor that promotes the generation of new neurons and stimulates the migration of these new neurons to their proper place in the brain, particularly in the hippocampus. This provides great encouragement for all of us to keep active and moving.
Since 2007, over 350 twin pairs have assisted the OATS team with their research, some participants on up to four occasions. In the last 10 years, OATS researchers have performed 1667 assessments of health, cognition (ability to remember, pay attention, and concentrate), lifestyle factors. OATS have also collected and analysed 1439 blood samples, and obtained and analysed 1126 MRI brain scans.
Most recently, OATS has collected data from 207 PET scans capable of measuring the amount of the protein beta-amyloid in brain tissue of living individuals. High levels of beta-amyloid in the brain are associated with Alzheimer’s disease, and these data will allow us to determine the extent to which genetic and environmental factors contribute to accumulation of beta-amyloid in brain.
Next year, OATS will invite existing and new participants to contribute to the next stage of our study. We are excited to announce that we are changing to an online computerised survey and assessment of cognition, and involving regional pathology services in collection of blood samples for genetic analysis, in order to reach a wider section of the Australian population. We look forward to new findings from OATS data in 2018.
Brouwer RM, Panizzon MS, Glahn DC, Hibar DP, Hua X, Jahanshad N, et al. Genetic influences on individual differences in longitudinal changes in global and subcortical brain volumes Results of the ENIGMA plasticity working group. Human Brain Mapping. 2017. 38(9):4444-4458. doi: 10.1002/hbm.23672.
Hibar DP, Adams HHH, Jahanshad N, Chauhan G, Stein JL, Hofer E, et al. Novel genetic loci associated with hippocampal volume. Nature Communications. 2017;8: 13624. doi: 10.1038/ncomms13624.