Tracking neuronal transcriptional programs Early in brain development, cortical neurons are born near the ventricles, then migrate to their functional destinations. Telley et al. used a fluorescent labeling technique to see what transcripts characterize these earliest stages of neural development. Waves of transcriptional programs are initiated, then passed by as the neuron progresses from proliferative to migratory and finally to connectivity phases. Science , this issue p. 1443