Researchers have identified two genes that affect brain size and having a connection with both IQ and the risk of developing brain disorders like Alzheimer’s.
Scientists have known for some time that the size and volume of parts of the brain are related to specific disorders, including autism and Alzheimer’s disease. Autistic children’s brains, for example, tend to be higher than those of children who do not suffer from this disease and in patients suffering from Alzheimer brain region responsible for memory, the hippocampus, tends to be lower.
Brain size tends to be a trait that children inherit from their parents, suggesting that genes play an important role. This in turn suggests that genes influence brain vulnerability to certain diseases that depend on brain size, it is especially genes that affect memory and linguistic ability.
To identify genes responsible for brain size, more than 200 researchers from 100 institutions around the world have used two sophisticated techniques: machine-studied brain magnetic resonance imaging the brains of 21,151 people, both healthy and suffering from depression, anxiety, Alzheimer’s and schizophrenia, and then analyzing in detail and their DNA.
The study found that two genetic variants important. One of them affects the overall size of the brain, and the other is associated with hippocampal volume (called “central memory”), which tends to be lower in people with dementia.
“None of these genetic variants will not guarantee that the person has to suffer from these diseases, but the likelihood of this happening increases significantly,” said Paul Thompson, professor of neurology and psychiatry at UCLA School of Medicine and also study coordinator.
People who had a genetic variant associated with smaller hippocampus of the brain showed a decrease similar to what takes place during the five years of aging. This, explains Thompson, is that reduction of brain function that occurs during aging will be accelerated if these people.
“People who have this gene are actually five years older than it should be. This is an important genetic discovery,” said Thompson.
Other genetic variant discovered by team of scientists was correlated with brain volume, is also associated with changes in IQ of 1.3 points. Gene effect on IQ was small, but significant, was observed in tests.
Scientists believe that the discovery of these two genetic variants can lead to improved diagnosis and treatment of brain disorders. If Alzheimer’s disease, experts believe that people can use brain stimulation techniques, including physical activity, learning and social interaction to strengthen the neural structures, building a “stock” cognitive equivalent of a savings fund for the brain. As neural networks are deteriorating with age, the brain may turn to the “stock” built over time to compensate for tissue loss.
If people have now identified genetic variants of scientists, the “stock” is smaller, so are more vulnerable to external factors such as obesity or alcohol abuse, which in turn reduces brain volume.
Researchers say that the study suggests that brain imaging is an effective method to identify gene activity, is possible to observe their contribution to diseases before they cause symptoms. “Our results represent an important medicine in developing brain, providing a better understanding of the methods by which we can prevent brain decline,” concluded Thompson.