Autistic brains are heavier, with more neurons: study

[FarCenter]

A post-mortem analysis of half a dozen autistic boys showed that their brains were heavier and contained many more neurons than counterparts without the disorder, US researchers said Tuesday.

The study, while small, suggests that brain overgrowth may be occurring in the womb, according to the findings published in the November 9 issue of the Journal of the American Medical Association.

Researchers examined the brains of seven autistic boys, age two to 16, most of whom had died by drowning. The 16-year-old's cause of death was undetermined and one eight-year-old died of muscle cancer.

When they compared them to a control group of six boys without autism who died in accidents, they found that the brains of autistic boys had 67 percent more neurons in the prefrontal cortex and were nearly 18 percent heavier than normal brain weight for age.

"Because cortical neurons are not generated in postnatal life, this pathological increase in neuron numbers in autistic children indicates prenatal causes," the study said.

http://www.france24.com/en/20111109-autistic-brains-are-heavier-with-more-neurons-study

[greymattermom]

1. incorrect logic

In the cortex, more neurons are generated than needed, and many die during the early postnatal period. The excess number of neurons does not have to be due to a prenatal cause.

[FarCenter]

2. Neuron Number and Size in Prefrontal Cortex of Children With Autism

Abstract at http://jama.ama-assn.org/content/306/18/2001.short


Increased Neuron Number and Head Size in Autism

Abstract of editorial http://jama.ama-assn.org/content/306/18/2031.short

Unfortunately, the full text articals are all behind a paywall, so popular media accounts are all the unwashed masses can read.