Researchers have created a mouse model of autism by knocking out a gene that is, in humans, associated with a form of the disorder that is often accompanied by epilepsy.

Daniel Geschwind at the University of California, Los Angeles, and his colleagues found that mice lacking the Cntnap2 gene were hyperactive, displayed abnormal social and repetitive behaviours, and had seizures. Certain classes of neurons in the cortex of the animals' brains were in the wrong regions, suggesting abnormal neuronal migration. The brains also had reduced numbers of interneurons — cells that provide the major inhibitory signals in the brain. The authors suggest that these changes could lead to abnormal neuronal circuits, which could then interfere with neuronal firing and cognitive behaviours.

Treating the mice with the antipsychotic drug risperidone reversed the repetitive behaviours, but had no effect on social behaviour.

Cell 147, 235–246 (2011)