Researchers have cultured stem cells from people with autism spectrum disorder (ASD) to form brain-like structures in the lab, revealing errors in neuronal development.

Flora Vaccarino of Yale University in New Haven, Connecticut, and her colleagues took skin cells from four people with ASD and their unaffected relatives, and reprogrammed the cells into stem cells. They then made 'mini-brains' using 3D cultures of the cells, which recreated human forebrain development 9–16 weeks after conception. The team found that compared to control cultures, ASD cultures contained more neurons that produce a brain-signalling molecule, GABA, which inhibits neuronal activity. One reason for this difference was that the ASD cells overexpressed the FOXG1 gene; correcting this reduced the growth of GABA-producing neurons.

The four people did not share any obvious genomic changes, suggesting that different genetic factors for autism can cause the condition by affecting similar neurobiological mechanisms during fetal growth.

Cell 162, 375–390 (2015)