Autism changes molecular structure of the brain, study finds

In a new study by the UCLA, scientists have been able to measure the expression levels of more than 20,000 genes in tissue samples from autistic and healthy brains.

For decades, autism researchers have faced a baffling riddle: how to unravel a disorder that leaves no known physical trace as it develops in the brain

Now a UCLA study is the first to reveal how the disorder makes its mark at the molecular level, resulting in an autistic brain that differs dramatically in structure from a healthy one. Published May 25 in the advance online edition of Nature, the findings provide new insight into how genes and proteins go awry in autism to alter the mind.

"We were surprised to see similar gene expression patterns in most of the autistic brains we studied," said first author Irina Voineagu, a UCLA postdoctoral fellow in neurology. "From a molecular perspective, half of these brains shared a common genetic signature. Given autism's numerous causes, this was an unexpected and exciting finding."

From what I take of this, this means that although autism can present itself in a wide range of ways, scientifically speaking it is all by the same process.

"In a healthy brain, hundreds of genes behave differently from region to region, and the frontal and temporal lobes are easy to tell apart," Geschwind said. "We didn't see this in the autistic brain. Instead, the frontal lobe closely resembles the temporal lobe. Most of the features that normally distinguish the two regions had disappeared."

The frontal lobe is responsible for decision making, problem solving, control of purposeful behaviour, consciousness and emotions. So you can sort of see how a not fully functioning frontal lobe could cause the problems that are exhibited in autism

"Several of the genes that cropped up in these shared patterns were previously linked to autism," said Geschwind. "By demonstrating that this pathology is passed from the genes to the RNA to the cellular proteins, we provide evidence that the common molecular changes in neuron function and communication are a cause, not an effect, of the disease."

The next step will be for the research team to expand its search for the genetic and related causes of autism to other regions of the brain.

Autism changes molecular structure of the brain, study finds

I wonder how this new evidence relates to mirror neurons. Is a mirror neuron a particular kind of "gene-expression level"?