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5 December 2013 11:26 am ,
Vol. 342 ,
At age 30, Dutch biologist Freek Vonk has built up a respectable career as a snake scientist. But in his home country,...
Since arriving on the island of Guam in the 1940s, the brown tree snake ( Boiga irregularis ) has extirpated native...
An animal rights group known as the Nonhuman Rights Project filed lawsuits in three New York courts this week in an...
Researchers have been hot on the trail of the elusive Denisovans, a type of ancient human known only by their DNA and...
Thousands of scientists in the Russian Academy of Sciences (RAS) are about to lose their jobs as a result of the...
Dyslexia, a learning disability that hinders reading, hasn't been associated with deficits in vision, hearing, or...
Exotic, elusive, and dangerous, snakes have fascinated humankind for millennia. They can be hard to find, yet their...
Researchers have sequenced and analyzed the first two snake genomes, which represent two evolutionary extremes. The...
- 5 December 2013 11:26 am , Vol. 342 , #6163
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Memories May Need Fresh Neurons
16 March 2001 7:00 pm
Neurons are the stuff memories are made of, and new memories may require new stuff, according to a report just released. If researchers treat rats with a drug that kills budding neurons, the rats develop memory problems. The finding suggests that a steady, lifelong supply of fresh neurons may be important for maintaining the brain circuits that encode memories.
For many years, neuroscientists thought that the brains of adult mammals don't grow additional neurons. Then studies showed that neurons pop up throughout life in some regions of the brain, including the hippocampus, an area important for building new memories. However, whether these new neurons actually do anything important has remained a mystery.
To address this question, behavioral neuroscientist Tracey Shors of Rutgers University in Piscataway, New Jersey, and colleagues treated rats with a drug called MAM that kills proliferating cells, including developing neurons. They then trained these rats, along with a group of normal rats, on a memory task known to require the hippocampus. In each trial, the rats heard a brief buzzing sound followed by a short delay and then a mild shock to the eyelid. After a few dozen repetitions, normal rats got wise and blinked when they heard the noise. However, the treated rats were much less likely to blink--even after hundreds of trials. Apparently, the rats didn't remember the experiences, the researchers report in the 15 March issue of Nature. The deficit did not appear to be due to the toxic side effects of MAM, the authors say, because the rats performed well on a memory task that doesn't involve the hippocampus.
The study answers a question that has lingered ever since the discovery that adult brains can grow new neurons, says neurobiologist Rob Malenka of Stanford University. Now it seems that the new neurons do have an important function, at least in the hippocampus. "It's an experiment that clearly needed to be done, and I admire them for actually doing it," Malenka says.