Ideas abound even at the end of the journey

FFor more than 15 years, I have had the pleasure of helping The scientist cover everything from the latest news on an emerging pandemic to the latest research breakthroughs that shake up long-standing mysteries. Depending on the day, this job is a mix of challenge, fun and education. Some days are more difficult. Others contain more delicacies. But one thing has remained constant throughout my tenure at this publication: science and the world it probes never cease to amaze me.

Recently, I was reminded of this fact in a beautifully mundane way. During a briefing in early November – of the type we hold weekly to explore research activities in the life sciences – editorial staff discussed a study that claimed to uncover the neural circuits responsible for vomiting control. The research, published in a November issue of Cell, used mice as experimental models. The authors of the paper exposed the animals to bacterial toxins and a chemotherapeutic drug to induce a behavioral response, then traced the signaling cascade that elicited the response.

But here’s the catch: mice can’t vomit. It’s not that they won’t vomit or that it’s extremely difficult to get that particular behavior in Mus musculus. Mice, by their physiology, cannot vomit. Now anyone who writes about or directs science, especially biomedical science, is fully aware that the humble mouse is one of, if not the, the most common experimental organisms. We at The scientist are practically inundated with mice, because our mission is to cover basic research in biology, for which mice have long served as subjects. And yet, this simple fact of mouse biology had eluded my appreciation for all these years.

This physiological reality stopped me dead. How did modern mice, let alone their evolutionary ancestors, persist without the ability to forcefully eject toxins or otherwise nasty substances from their digestive tracts? What does a mouse do when it finds itself in the precarious position of having ingested something that could cause many other mammals to lose their lunch, possibly saving their lives?

These questions nagged me enough to do some superficial reconnaissance, which taught me that mice aren’t the only species in this particular boat. Large rodents (squirrels, rats, gophers, etc.) cannot vomit. Horses are also part of the anti-vomiting club. Fascinating. And it’s only recently researchers began to explore why it is that rodents lack what appears to be an advantageous reflex. (Spoiler alert: the answer lies deep in the brainstem, where the neurological components needed to initiate vomiting appear to be lacking.)

Regarding the recent study, skilfully covered for our website by intern Katherine Irving, the authors creatively circumvented the curious murine deficiency by using a proxy for nausea involving twisted facial expressions and tight abdominal muscles. The rest is living history, with a perfectly described pathway from the serotonin toxin to a specific region of the mouse brain, which houses neurons that fire to trigger gagging.

This particular example involves me, as a non-scientist, being caught off guard by a scientific fact that is surely known to a large number of scientists. Nonetheless, learning something so fundamental about the biology of a ubiquitous laboratory animal reminded me that despite all that humanity has learned about the natural world, surprises still abound. If we extend the perimeters of our investigation beyond Earth and into the universe, there are even more massive unknowns. Dark matter, dark energy, the nature and lifespan of black holes, to name a few.

It’s an exciting and oddly comforting feeling to know that we don’t need to peer into the darkest recesses of space to feel afloat in a sea of ​​potential knowledge. We can find pockets of discovery and wonder much closer to home. In mice, for example. And deep within the cells and molecules of our own bodies – in fact, in the very brains we use for this whole puzzle – lie untapped mysteries, insights waiting to be discovered.

I go from The scientist, and I leave behind a body of work that I hope captures my wonder and awe at the natural world and the concerted human effort to understand its intricacies. But I sincerely hope never to outgrow the dizzying fascination I feel whenever I encounter individuals with a similar impulse, whether they be science journalists covering emerging concepts or researchers on the front lines of discovery.

Bob Grant

Chief Editor