The Week: A New Shrew and Mice Memory

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New research shows that cheetahs do not overheat when hunting, even when they hit their top speeds.

Scientists discovered a new species of shrew, corrected erroneous beliefs about the body temperature of cheetahs, fed bees polluted pollen with disastrous results and planted a false memory in the mind of a mouse. In the meantime, NASA wants to know why a spacewalking astronaut's helmet suddenly took on water.

Developments

ENVIRONMENT

Poison Pollen

Agricultural chemicals may be killing the honeybees that are essential for a successful harvest. Researchers at the University of Maryland and the Agriculture Department collected pollen from commercial beehives and found them polluted with as many as 35 different pesticides, often from fields other than the ones in which the bees were placed for pollination. Healthy bees that ate pollen polluted with the fungicide chlorothalonil were more than twice as likely to be infected by Nosema ceranae, the parasite implicated in colony collapse disorder. The study does not conclusively link the chemicals with colony collapse disorder, but as the authors write in PLoS One, the results strongly suggest that "a detrimental interaction occurs when honeybees are exposed to both pesticides and Nosema."

WILDLIFE

New Shrew

Scutisorex thori, a small shrew with a backbone so strong it can bear the weight of a grown man, was discovered in 1910. Since then it has been assumed that it was the only member of its species. But now scientists in the Democratic Republic of Congo have found another Scutisorex, an animal with a back reinforced with bones that give it a spine as strong as its cousin's. The scientists established its relationship to S. somereni by DNA analysis and described their find in Biology Letters. They have named it Scutisorex thori.

Very Fast, Very Cool

For at least 30 years, scientists have believed that cheetahs fail to catch their prey more often than other big cats because they overheat at high speeds. But researchers in Namibia who implanted sensors in six cheetahs tell a different story. Even when one of the study animals came close to the maximum chase distance ever reported for a cheetah, his body temperature did not exceed that of his regular 24-hour average. After the hunt, cheetahs' temperatures rose slightly, more when the hunt was successful than when it was not. The researchers attribute this temperature increase to the stress of protecting a kill from other predators.

BRAIN SCIENCE

Flawed Remembrance

Scientists at M.I.T. believe they have successfully planted a false memory in the brains of mice. They let mice get used to a certain environment so that they would remember it, and chemically labeled the neurons where the memory was laid down. A day later, in a different environment, they delivered a shock to the mice while activating the neurons involved in the memory of the first environment. Then they brought the mice back to the original environment, and stimulated those brain cells again. The mice froze in fear — acting on the memory of a shock in that environment that had never happened. After experimenting further, the scientists became convinced that the mice were acting on a false memory. Susumu Tonegawa, the lead researcher, said the work raised the question — so far unanswered — of why mammalian brains are built to allow false memories at all.

Coming Up

SPACEFLIGHT

Wardrobe Malfunction

The Italian astronaut Luca Parmitano had a serious scare on July 16 when globs of water floated into his helmet during a spacewalk, eventually covering his eyes and nose. "I experienced what it's like to be a goldfish in a fish bowl from the point of view of the goldfish," he said in an interview from the International Space Station. Now NASA wants to know why it happened. A five-member board led by Chris Hansen, the station's chief engineer, will convene on Aug. 2 to try to figure it out. Until then, NASA has sent some spacesuit-repair tools up to the space station in an unmanned Russian cargo ship.

This article has been revised to reflect the following correction:

Correction: August 4, 2013

An item in the Week column last Tuesday about the recent discovery of Scutisorex thori, an African shrew with an extremely strong spine, referred incorrectly to its cousin S. somereni. Until now, somereni, discovered in 1910, was thought to be the only member of its genus  — not its species.

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