Although it's our most vital organ, surprisingly little is known about what constitutes a 'normal' brain. That makes it harder to uncover what's gone awry in people suffering from mental illness and other brain-associated disorders, and ultimately, it often leaves physicians treating symptoms rather than causes of conditions such as Alzheimer's and Parkinson's disease, schizophrenia, attention deficit hyperactivity disorder (ADHD), and many other ailments.
That's why researchers from two San Antonio institutions have combined forces for the largest study of its kind to map out normal variations in brain structure and function and identify the genes responsible for those variations. They expect their five-year investigation - funded with two new cooperative grants totaling $7 million from the National Institute of Mental Health - to yield a host of new data on basic brain biology and mental illnesses, as well as spawn additional studies focusing on specific diseases.
Why study what's 'normal'?
Because scientists have not developed a good understanding of basic brain biology and the role of genes, they do not know the root causes of most mental disorders, said geneticist John Blangero, Ph.D., of the Southwest Foundation for Biomedical Research, who is leading the study with David Glahn, Ph.D., psychologist and associate professor at the University of Texas Health Science Center at San Antonio.
To get to the heart of the matter, Blangero and Glahn are taking a different approach from many previous studies of the brain. Rather than looking for research subjects suffering from a particular mental illness and studying differences in their brain structure and function, this research team is working with large family groups from the average population to better understand normal brain variation and the genes that control it.
'We want to inform aspects of brain biology that are relevant for a lot of different diseases,' Blangero said. 'That's why we're not focused on any disease. We're focused on finding the genes that influence normal brain variation. Those are going to be the same genes that also influence pathological variations.'
'This gives us the potential to evolve some of the basic questions that we're constantly dealing with from the side of neurologic and psychiatric illness, research areas where it's difficult to gain traction when you're focused on the disease itself,' explained Glahn. 'This is because the things we're interested in -- be they cognition, brain structure or brain physiology - are changed dramatically in people with mental illness. So we [in the psychiatric community] are constantly questioning, 'Is this change [in the brain] a cause of the illness? A result of the illness? A result of treatment of the illness?' By studying the biology of the brain in healthy subjects, we'll be able to overcome the 'chicken-and-egg' problem that's constantly there in clinical research.'