Nature Reviews Neuroscience, Published online: 22 June 2026; doi:10.1038/s41583-026-01056-y N6-Methyladenosine (m6A) is installed on many mRNAs and non-coding RNAs and regulates gene expression by affecting RNA–protein interactions. In this Review, Enakshi Sivasudhan and Kate Meyer discuss how m6A is dynamically regulated and interpreted, and examine its role in brain function and disorders.