Evidence of Unstable Blood Flow in Autistic Brains

A team of scientists has found evidence that people with autism have unstable vessels in the brain which prevents the proper delivery of blood flow, according to research published in the Journal of Autism and Developmental Disorders.

“In a typical brain, blood vessels are stable, thereby ensuring a stable distribution of blood,” said Patricia Whitaker-Azmitia, PhD, professor in the Department of Psychology and director of the Graduate Program in Integrative Neurosciences at Stony Brook University, N.Y.,  in a statement. “Whereas in the autism brain, the cellular structure of blood vessels continually fluctuates, which results in circulation that is fluctuating and, ultimately, neurologically limiting.”

For their study, the researchers examined human postmortem brain tissue both from normal brains and from brains with a diagnosis of autism. During microscopic analysis, the researchers were blind to whether the tissue came from a normal or autistic brain.

In the autistic brain tissue, the researchers found the presence of angiogenesis, the creation of new blood vessels. They did not find this in the normal brain tissue.

Evidence of angiogenesis in the autistic brains indicates that blood vessels are repeatedly being formed and are in constant flux, demonstrating instability in the mechanism that delivers blood to the brain. Specifically, the researchers found increased levels of the proteins nestin and CD34 in autistic brains, which are molecular markers of angiogenesis.

Maura Boldrini, MD, PhD, a research scientist in the Department of Psychiatry at Columbia University, noted in a news release that angiogenesis in autism could be affecting brain plasticity.

“We found that angiogenesis is correlated with more neurogenesis in other brain diseases,” Boldrini said. “[There is therefore] 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.”

“It’s clear that there are changes in brain vascularization in autistic individuals from 2 to 20 years that are not seen in normally developing individuals past the age of 2 years,” said Dr. Azmitia. “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.”


Azmitia EC, wt al. Persistent Angiogenesis in the Autism Brain: An Immunocytochemical Study of Postmortem Cortex, Brainstem and Cerebellum. J Autism Dev Disord. 2015; doi:10.​1007/​s10803-015-2672-6.