The underlying biology of age-related memory glitches — in old mice and old people — is different from what happens with Alzheimer's, recent research suggests. Anthony Bradshaw/iStockphoto.com hide caption

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Belgian Blue bulls look like they are made of muscle because they have a mutation in the gene that codes for the protein myostatin. In humans, as in other types of cattle, myostatin normally limits the number of muscle fibers that form before birth and then limits the growth of those fibers later on. Courtesy of Se-Jin Lee and Alexandra McPherron/PNAS hide caption

itoggle caption Courtesy of Se-Jin Lee and Alexandra McPherron/PNAS

A gene known as DRD2 affects the brain's dopamine system and is known to be associated with aggressive behavior. iStockphoto.com hide caption

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Patong beach in Phuket, Thailand, was destroyed by the tsunami on Dec. 25, 2004. More than 230,000 people died. Gamma-Rapho via Getty Images hide caption

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Instructional assistant Jessica Reeder touches her nose to get Jacob Day, 3, who has autism, to focus his attention on her during a therapy session in April 2007. Rich Pedroncelli/AP hide caption

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Barton Holmes, 2, sits with his father, Kevin Holmes, and his mother, Catherine McEaddy Holmes, during an appointment at Children's National Medical Center in Washington, D.C. Maggie Starbard/NPR hide caption

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Hurricane Sandy churns off the Atlantic coast on Oct. 29. NOAA officials are forecasting seven to 11 hurricanes, compared with about six in a typical season. NASA/Getty Images hide caption

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Despite significant advances in neurology and imaging, researchers still don't have simple lab tests for diagnosing patients with mental disorders. Diagnoses are still mostly based on a patient's signs and symptoms. BSIP/UIG via Getty Images hide caption

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Although a flying pig doesn't exist in the real world, our brains use what we know about pigs and birds — and superheroes — to create one in our mind's eye when we hear or read those words. iStockphoto.com hide caption

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Bates experienced migraines as a child. She made this painting to depict how they felt to her. Courtesy of Emily Bates hide caption

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In this Jan. 18 photo provided by the NYU Langone Medical Center, a technician examines mice to determine their health at the hospital's complex in New York. New York University/AP hide caption

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Scientists hope a new genetically modified rat will help them find Alzheimer's drugs that work on humans. Ryumin Alexander/ITAR-TASS/Landov hide caption

itoggle caption Ryumin Alexander/ITAR-TASS/Landov