Mouse brain olfactory bulb crossection

A crossection of the middle of the mouse olfactory bulb, depth-coded.

The neurons you see express tdTomato fluorescent protein, with the signal boosted by an antibody.

The two cheerful rows of layered neurons are mitral cells.

When a mitral cell fires, it wakes its inhibitory neighbours, which quiet both it and the cells nearby. That contrast-sharpening is what makes two similar smells easier to tell apart.

🌈TRPV1-tdTomato (Transient Receptor Potential Vanilloid 1 tagged with tdTomato)