A growing body of evidence suggests that autism involves atypical communication between brain regions, but how and where in the brain this plays out is unclear.

The brains of autistic children show few differences from those of children with attention deficit hyperactivity disorder, or even of controls.

Children who have repetitive behaviors, a core autism trait, may show particular patterns of brain activity as early as 1 year of age.

Administering a cholesterol drug alongside an antibiotic eases atypical behavior and restores the signaling balance in the brains of people with fragile X syndrome.

Mice and people missing a copy of a chromosomal region called 16p11.2 show similar patterns of weak brain connections.

The brains of men with autism may have a mosaic of features from both genders.

The drug mavoglurant has no effect on a brain circuit involved in social behavior in a mouse model of fragile X syndrome. That may explain its poor performance in people with the condition.

Differences in sleep and circadian rhythm may distort the results of autism studies.

A different set of genes regulates brain activity in people with autism than the set involved in controls.

People with autism show frequent swings in synchronized activity between brain regions, a finding that could explain inconsistencies across studies.