Cool Mice Live Longer

Extended Life Span in Mice Genetically Engineered for Low Body Temperature

From the WebMD Archives

Nov. 2, 2006 -- Cool mice live longer, find scientists at Scripps Research Institute.

No, the mice aren't more hip than other mice. They've been genetically engineered to have a slightly lower body temperature than normal mice.

The low body temperature -- about one-half to one degree Fahrenheit lower than normal -- doesn't seem to hurt the mice. During infections, they get fevers that spike as high and last as long as those of normal mice. And they have normal appetites -- especially male cool mice, which gain a bit of extra weight as they age.

But the cool mice live significantly longer than normal mice. Females lived about 20% longer than normal. Males lived about 12% longer.

It's already known that animals live longer if put on a very low-calorie diet. One explanation for this is that burning fewer calories lowers body temperature. So Bruno Conti, PhD, Tamas Bartfai, PhD, and colleagues came up with a plan to lower the body temperature of mice.

They genetically engineered a strain of mice that make excessive amounts of a heat-generating protein in a specific brain region -- the brain's internal thermostat. If you heat the thermostat in your home, the thermostat will be tricked into thinking it's hot and will turn down the heat. The same thing happens in the brains of cool mice.

Of course, the point isn't simply to make mice that live longer. The researchers -- who have spent five years on this project -- hope that future drugs or devices could be used to extend human lives.

"This mechanism, we believe, will be a good target for pharmacological manipulation or heating," Bartfai said in a news release.

The findings appear in the Nov. 3 issue of the journal Science.

WebMD Health News Reviewed by Louise Chang, MD on November 02, 2006

Sources

SOURCES: Conti, B. Science, Nov. 3, 2006; vol 314: pp 825-828. News release, Scripps Research Institute.

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