For many years, some parents have noticed that their autistic children’s behavioral symptoms diminished when they had a fever. This phenomenon has been documented in at least two large-scale studies over the past 15 years, but it was unclear why fever would have such an effect.
A new study from MIT and Harvard Medical School sheds light on the cellular mechanisms that may underlie this phenomenon. In a study of mice, the researchers found that in some cases of infection, an immune molecule called IL-17a is released and suppresses a small region of the brain’s cortex that has previously been linked to social behavioral deficits in mice. (Study may explain how infections reduce autism symptoms)
This article also discusses findings that show increased incidence of autism among children born of mothers who suffered viral or bacterial infections during pregnancy.
The cause seems to be the same molecule, IL-17a, responsible for relief of autistic symptoms during fever.