In a study involving nematode worms, scientists found that when these worms were exposed to a specific compound released by harmful bacteria, it triggered the activation of a neural pathway. This activation led to an increase in the lifespan of the worms and a reduction in protein aggregation, which is known to be a contributing factor in the development of neurodegenerative illnesses.

An organism’s reaction to repugnant odors can be an indicator of the organism’s capacity to protect itself from harmful substances and live longer. This at least is what happens in the case of nematodes of the species Caenorhabditis elegans.

— Read more in The Scent of Longevity: How Smelling Harmful Substances May Prolong Life at SciTechDaily.

When a cat takes a sniff, airflow is diverted into two different streams for breathing and smelling. The model showed that the animal’s nasal passages then direct the smelling stream through an extensive network of tightly coiled, sensor-studded channels called turbinates. The scientists hypothesize that this structure may function like a gas chromatograph—a sophisticated chemical device that separates different compounds based on their solubility. Scents that dissolve less easily in nasal mucus travel farther than more readily dissolved ones and therefore bind to more distant smell receptors.

— Read more in Cat Noses Contain Twisted Labyrinths That Help Them Separate Smells at Scientific American.