Apr 5: Our bodies and brains fight weight loss, and more...
Magnets for brain surgery, fish use tools, cold plunge benefits, and narwhals play with their horn
On this week's episode of Quirks & Quarks with Bob McDonald:
A Canadian team is developing minimally-invasive micro-tools for brain surgery that can be operated by magnetic fields from outside of the skull. The tools, including scalpels and forceps, will enter the cranium through small incisions, and then be controlled by focused and precise magnetic fields. Eric Diller is associate professor of mechanical and industrial engineering at the University of Toronto and his team's research was published in the journal Science Robotics.
In recent decades scientists have discovered animals from primates to birds and marine mammals can use tools — a capacity once thought to be exclusive to humans. Now scientists have discovered fish using hard surfaces to crack open hard-shelled prey and get at the meaty meal inside. The research, led by Juliette Tariel-Adam from Macquarie University, included recruiting divers and scientists from around the world to report any sightings of tool use, which led to 16 reports across five species of wrasses. The results were published in the journal Coral Reefs.
For a hardy few, soaking in cold water has long been held out as being healthful and invigorating. Well, unfortunately, the latest research suggests that they're right. Volunteers who soaked in cold water for an hour a day for a week showed improvements in autophagy, an important cellular clean-up function that typically declines with age. Kelli King is a postdoctoral researcher at the University of Ottawa and was co-lead on this study, published in the journal Advanced Biology.
The narwhal is a small whale distinguished by its long spiral horn — an elongated tooth. Researchers have long speculated about what the ostentatious bit of dentition is actually for, but the elusive narwhal has, until now, been hard to study. Now scientists, including Cortney Watt from Fisheries and Oceans Canada, have used drones to learn that the horn is used in several ways: to play, explore and forage. The research was published in the journal Frontiers in Marine Science.
New research is revealing why it's so difficult to keep weight off after you've lost it.
One study in Nature found that genes in the fat cells of people who lost a significant amount of weight through bariatric surgery largely continued to behave as if they were still obese. Ferdinand von Meyenn, from ETH Zurich, said that despite these individuals becoming, in many respects, much more healthy, genes that became active during obesity remained active, and genes that were turned off, remained turned off, predisposing them to regain lost weight. In formerly obese mice, their fat cells remained much better at taking up sugars and fats.
In addition, another study revealed that neurons in a primitive part of the brain hold onto memories of fat and sugar that can drive our cravings, according to a study on mice in Nature Metabolism. Guillaume de Lartigue, from the Monell Chemical Senses Center and the University of Pennsylvania, said specific neural circuits in the brain light up, depending on whether the gut received sugar or fat. Removing these neurons protected the mice from diet-induced weight gain, something de Lartigue is hoping to translate to humans to dial down impulsive eating behaviour.
