A strain of mice with autism-like behaviors is missing a corpus callosum, a bundle of nerve fibers that connects the two hemispheres of the brain. Two studies published this month investigate the link between these two features.

Growing evidence suggests that abnormal connectivity in the brain underlies autism, but conflicting interpretations persist about where and how the dysfunction occurs. How do we investigate the underlying mechanisms of this theory?

New methods to deal with motion artifacts in brain imaging data are critically important, says Mike Tyszka.

‘Underconnectivity’ is considered one of the best-supported theories for the neural basis of autism. But many questions remain unanswered, says Jon Brock.

To better understand how local connectivity is altered in autism, we first need to define what it means, says Tal Kenet.

A number of studies have found no connectivity differences between people with autism and controls, but few have been published so far, says Dan Kennedy.

Autism may result from reduced anatomical connectivity and functional connectivity between the frontal cortex and more posterior areas of the brain, say Marcel Adam Just and Timothy Keller.

Researchers can use functional magnetic resonance imaging to map fetal brain connectivity during the second and third trimesters of pregnancy, according to a study published 20 February in Science Translational Medicine.

In 2003, John Rubenstein and Michael Merzenich first described the theory, now popular in autism, that the disorder reflects an imbalance between excitation and inhibition in the brain. Takao K. Hensch and Parizad M. Bilimoria review the paper and its impact on the field.

Connections between neighboring groups of brain cells are weaker in individuals with autism than in controls, according to a report published 14 January in the Proceedings of the National Academy of Sciences.