Cover legend: The first-order olfactory interneurons, projection neurons (white), are labeled in the Drosophila brain (orange). They receive processed odor information in the first olfactory brain center, antennal lobe, and further convey it to the two brain structures: the mushroom body and lateral horn. The study revealed that one of the multiple memory traces for olfactory reward learning is mapped to these projection neurons. For more information, see the article by Thum et al. in this issue (pages 11132–11138).