Children with autism have 67 percent more neurons in dorsolateral, mesial prefrontal cortex
TUESDAY, Nov. 8 (HealthDay News) -- Brain overgrowth in male children with autism involves an increase in the number of neurons in the prefrontal cortex (PFC), according to a study published in the Nov. 9 issue of the Journal of the American Medical Association.
Eric Courchesne, Ph.D., from the University of California San Diego in La Jolla, and colleagues investigated whether early brain overgrowth in children with autism is associated with the number of neurons in the PFC. Postmortem prefrontal tissue from seven male children with autism and six controls (aged 2 to 16 years), who died between 2000 and 2006, were compared for the mean number and size of neurons in the dorsolateral (DL-PFC) and mesial (M-PFC) subdivisions of the PFC. Associations between neuron number and deviation in brain weight from normative values for age were assessed.
The investigators found that, compared to controls, children with autism had 67 percent more neurons in the PFC, including 79 percent more in DL-PFC and 29 percent more in M-PFC. There was a mean difference of 17.6 percent between the brain weight of autistic children and the normative mean weight for age. The mean difference between brain weight of controls and the normative mean weight for age was 0.2 percent. When counts were plotted by weight, children with autism were found to have greater total prefrontal neuron counts and brain weight for their age than controls.
"In this small preliminary study, brain overgrowth in males with autism involved an abnormal excess number of neurons in the PFC," the authors write.
One of the authors disclosed financial ties to Sinq Systems, which performed data collection and analysis for this study. The author is also an applicant on a pending U.S. patent related to analysis of microscopic structure.
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