Although most current research on autism points to neurological make-up as a leading cause, a team of New York University scientists found that it may be linked to the composition and malfunctioning of blood vessels in the brain.
"Our findings show that those afflicted with autism have unstable blood vessels, disrupting proper delivery of blood to the brain," said Efrain Azmitia, senior author of the study, in a press release. "In a typical brain, blood vessels are stable, thereby ensuring a stable distribution of blood. Whereas in the autism brain, the cellular structure of blood vessels continually fluctuates, which results in circulation that is fluctuating and, ultimately, neurologically limiting."
The study examined human postmortem brain tissue from both autistic and normal brains using microscopic analysis. Each scientist conducting the analysis was unaware of whether the tissue they were examining came from a normal or autistic brain.
The results found angiogenesis, which refers to the creation of new blood vessels, in the brain tissue of autistic brains, but not standard brains. This points to evidence of vessels being repeatedly created, which could represent an instability in the blood's delivery mechanism. In particular, the scientists found increased levels of nestin and CD34, which are molecular markers for blood vessel creation, in autistic brains.
"We found that angiogenesis is correlated with more neurogenesis in other brain diseases, therefore there is the possibility that a change in brain vasculature in autism means a change in cell proliferation or maturation, or survival, and brain plasticity in general. These changes could potentially affect brain networks," said Maura Boldrini, co-author of the study.
"Now that we know this, we have new ways of looking at this disorder and, hopefully with this new knowledge, novel and more effective ways to address it," added Azmitia.
The findings were published in the Dec. 14 issue of the Journal of Autism and Developmental Disorders.
