Neurodevelopment Throughout life, new neurons are added to the brain. Just like people arriving late to a cocktail party, the newbies need to figure out how to integrate with those already embroiled in conversations. The zebrafish brain, already capable of complex visual processing at larval stages, accepts new neurons throughout the fish life span. Boulanger-Weill et al. tracked the location, movement, and functional integration of single newborn neurons in developing zebrafish larvae. Following their own developmental trajectories, newborn neurons began with limited dendritic arbors, no neurotransmitter identity, and spontaneous, but not directed, activity. As each neuron matured, its activity began to parallel that of its more mature neighbors. Spatial tuning curves shifted with further maturation, keeping the overall visual response in balance. Bringing new neurons into the fold seems to require synaptic connection with mature neurons already in place. Curr. Biol. 27 , 1707 (2017).