Despite the attention devoted to synapses, neurons can also release neurotransmitters at a distance from presynaptic terminals, such as along axonal hotspots. Such non-synaptic neurotransmission is implicated in the function of many neural circuits, but we have a poor understanding of the underlying molecular mechanisms and of how it impacts the nervous system. We use the zebrafish model organism to study both the axonal release mechanisms and the cellular responses to this understudied mode of cell-cell communication in the nervous system.