Naked mole rats are weird. They spend their lives almost entirely underground, are largely insensitive to some kinds of pain, can persist without oxygen for a long time, rarely develop cancer, and can live past 30 years, which is decades longer than similarly sized rodents. They are also eusocial, like ants, bees, or termitesβin a colony that can hold more than a hundred animals, only one female, the queen, breeds.
We didnβt know how exactly naked mole-rat queens stop other females from breeding. For a long time, our leading hypothesis was bullying and violence, but that may be a bit impractical, given their kingdoms are vast networks of tunnels that can stretch for up to three kilometers. But now a team of Lewin Lab scientists at Max DelbrΓΌck Center for Molecular Medicine in Berlin discovered itβs actually just one part of a sophisticated olfactory signaling program.
Running on smell
"It's very clear that mole rats actually have quite big noses and smell a lot," says Gary Lewin, a neurobiologist at the Max DelbrΓΌck Center for Molecular Medicine and senior author of the study. Naked mole rats have around 1200 olfactory receptor genes, more than mice (which have roughly 1,000 of them) and way more than the few hundred in humans. They're also blind. "They have to be able to navigate and move around without vision, so smell is one of those things thatβs enhanced," Lewin said.
About 14 years ago, Chrissi Kelly lost her sense of smell. She had traveled to the Czech Republic to visit family and caught some virus. Months later, when she still couldnβt smell, she made the rounds to doctors, including her general practitioner and an ear, nose and throat specialist, trying to find answers.
She was diagnosed with anosmia (smell loss), and like many patients with her condition, was told sheβd have to learn to live with it. But for her, the loss was catastrophic. βAfter about six months of complete loss, I was just climbing the walls, and I did not feel like myself anymore,β she says.
Researchers estimate that up to 22 percent of the population lives with smell impairments, like hyposmia (partial smell loss) or anosmia (complete smell loss). And many others live with smell disorders like phantosmia, in which a person picks up phantom smells, or parosmia, where typically pleasant scents like coffee or shampoo begin to register as highly unpleasant (think feces or vomit). Yet the conditions have been poorly understood, underdiagnosed and often minimized by clinicians.