First detailed ‘smell maps’ reveal how noses track odours

Key Points:

• Researchers have mapped around 1,100 olfactory receptors in the mouse nose with unprecedented detail, revealing that these receptors are arranged in tightly regulated horizontal stripes across the nasal epithelium, overturning the previous understanding of random receptor distribution within broad zones.
• The study involved analyzing about five million neurons from hundreds of mice using single-cell sequencing and spatial transcriptomics to pinpoint receptor locations, showing that each receptor occupies a specific overlapping stripe from the top to the bottom of the nose.
• The spatial organization of olfactory receptors is proposed to be developmentally controlled by gene sets, with retinoic acid playing a key role by forming a gradient that guides neurons to express the correct receptor type based on their position.
• This research challenges foundational textbook models of olfactory organization and provides new insights into how smell receptors are spatially mapped, potentially resolving longstanding questions in the field of olfactory neuroscience.