Oxford scientists report exciting new insights into the structure and function of the brain using genetic information and detailed brain images from UK Biobank.
The researchers took data from detailed MR images from 10,000 UK Biobank participants, which are freely available from the resource to researchers around the world, to examine thousands of different measurements of the brain.
It is hoped their results will provide a huge impetus to new research for a wide range of degenerative and psychiatric disorders. With a further 20,000 participants already imaged, and 70,000 more to be scanned in the next three years, the resource is set to transform research into brain development and aging, and understanding how it functions, becomes damaged by disease and heals itself, the scientists say.
The research has been led by Professor Stephen Smith, from Oxford’s Wellcome Trust Centre for Integrative Neuroimaging and Professor Jonathan Marchini, at the Wellcome Centre for Human Genetics, Oxford.
’We have had a tantalising glimpse of what could be,’ said Professor Smith. ’Both the genetics and imaging data are unparalleled in their depth and breadth. With imaging experts working alongside geneticists we hope to discover the causes of a wide range of brain disorders and find new ways to treat them.’
He said researchers were excited about what they had discovered. ’We have found a genetic fingerprint on some of the most fundamental processes that allow us to think, act and function, from the size of the parts of the central nervous system that control sight, hearing, speech, emotions and actions to the integrity of the communications channels between them and the strength of the signals within them,’ he said. The findings might help to better understand and ultimately improve treatments for a wide range of brain disorders, he said.
In particular, the researchers studied 3,144 different measures of brain structure and function, resulting in the discovery of more than 100 areas of the human genome that influence the brain:
Results revealed the effects of genes coding for a "scaffold for tissue healing" in white matter pathways, affecting diseases such as multiple sclerosis, stroke and motor neuron disease. This scaffold is crucial for the growth of white matter in early life, and for the white matter to heal itself from damage by disease.
The researchers mapped for the first time the signature of genetic influences on iron deposits in the brain, for genes related to neurodegenerative disorders such as Parkinson’s disease and Alzheimer’s disease. Researchers hope the work will lead to new insight into how these diseases progress and damage mental capacity, and also help generate new imaging-based ways to evaluate disease treatments in the future.
Another finding relates to the effect of the ROBO3 gene on the brain’s white matter pathways. Mutations in the gene mean that pathways that normally connect one side of the brain to the other do not develop properly. This can result in gaze palsy, a disorder which affects the movement of the eyes. It was found that the UK Biobank brain imaging is able to non-invasively localise the effects of this gene to exactly the pathways affected in this disorder.
The work also localised effects in the brain of genes that have been linked to both early-life brain development and mental health disorders such as depression and schizophrenia.
’The genetic basis of brain structure is largely unknown,’ said Professor GwenaŽlle Douaud, one of the brain imaging experts who collaborated on the work. ’We have found a very rich set of genetic effects which will help us understand better the mechanisms by which the brain develops, functions, becomes damaged by disease and heals itself. And this is from just 10% of the volunteer participants that will eventually get their brains scanned by UK Biobank.
’In the coming years, 100,000 volunteers will be imaged by UK Biobank, giving researchers and doctors around the world a massive resource from which to discover even more genetic influences, hidden to us so far, on the brain and its disorders.’
UKRI Chief Executive Professor Sir Mark Walport said: ’UK Biobank is one of the largest and most comprehensive studies of population health in the world. Genetic variation helps to explain important differences between people in health and disease. This largest ever investigation of the genetic basis of brain structure and function will provide unrivalled insights into neurodegenerative and psychological disorders, including Parkinson’s and Alzheimer’s diseases, depression and schizophrenia.’