Olfaction is one of the earliest sensory systems affected in Alzheimer’s disease, often declining years before measurable cognitive impairment. Yet the neural changes underlying this early sensory vulnerability remain largely unseen.

This artwork presents high-resolution imaging of the olfactory projection neurons in Drosophila melanogaster, shown side by side under normal conditions and in a fly model of Alzheimer’s disease. Conserved principles of olfactory circuit organisation make the fly a powerful system for visualising how neurodegeneration alters sensory pathways. Fluorescently labelled olfactory neurons (green) reveal striking differences in signal density, continuity, and spatial organisation between healthy and diseased brains.

By contrasting intact and disrupted olfactory circuitry, the work highlights smell as an early and sensitive indicator of neurodegeneration.