Scientists used light to raise a mouse’s heart rate, increasing anxiety-like behaviors in the animal. The study offers a new angle for studying anxiety disorders, Bethany Brookshire reported in “In mice, anxiety isn’t all in the head” (SN: 4/8/23, p. 9).
Heart rate isn’t everything, says neuroscientist Karl Deisseroth of Stanford University. The heart may race, but the brain provides important context, which is key to the body’s response. In the study, elevating a mouse’s heart rate in a neutral environment — such as a small, dim chamber — did not induce anxious behaviors, Deisseroth says. The anxious behaviors increased only when the heart rate was raised in a threatening context, like an open space where a small mouse could be a snack for a predator.
Some macaques inadvertently made stone flakes while using rocks to crack open nuts, raising questions about whether ancient stone flake tools attributed to hominids were made accidentally, Bruce Bower reported in “Monkeys’ stone flakes look like hominid tools” (SN: 4/8/23, p. 13).
Reader Jerald Corman wondered how scientists knew that the monkeys created the stone flakes unintentionally.
2023-05-29 06:00:00
Original from www.sciencenews.org
