July 1, 2012
Easter Island Drug Could Boost Cognitive Function
redOrbit Staff & Wire Reports - Your Universe Online
Rapamycin, an immunosuppressant typically used to prevent rejection in organ transplants, could help prevent diminishing cognitive skills, including memory retention, associated with aging or Alzheimer's disease, researchers at the University of Texas Health Science Center at San Antonio have discovered.
In a June 29 press release, the researchers said that they added the drug, which was first discovered in an Easter Island soil sample and approved by the FDA in September 1999, to the diet of healthy mice throughout their life spans.
Lead author Jonathan Halloran and colleagues discovered that rapamycin not only improved memory and learning in older mice, but also enhanced them in younger rodents and lowered their anxiety and depression-like behavior as well. They conducted "scientifically reliable tests" to accurately measure cognitive components in the mice.
"We made the young ones learn, and remember what they learned, better than what is normal," Dr. Veronica Galvan, assistant professor of physiology at the Barshop Institute for Longevity and Aging Studies, a division of the UT Health Science Center, said in a statement. "Among the older mice, the ones fed with a diet including rapamycin actually showed an improvement, negating the normal decline that you see in these functions with age."
In order to observe their behavior, Halloran's team used an elevated maze of tunnels leading to a catwalk. They discovered that mice that had consumed the rapamycin and had lower anxiety levels were more curious and more willing to explore the catwalk than those who had normal diets. Likewise, mice who were given antidepressants were more likely to struggle and try to get free when grabbed by their tails, the experts discovered.
"The reductions of anxiety and depressive-like behavior in rapamycin-treated mice held true for all ages tested, from 4 months of age (college age in human years) to 12 months old (the equivalent of middle age) to 25 months old (advanced age)," the school's press release said.
"The researchers measured levels of three 'happy, feel-good' neurotransmitters: serotonin, dopamine and norepinephrine. All were significantly augmented in the midbrains of mice treated with rapamycin," they added. "Rapamycin is an antifungal agent administered to transplant patients to prevent organ rejection. The drug is named for Rapa Nui, the Polynesian title for Easter Island. This island, 2,000 miles from any population centers, is the famed site of nearly 900 mysterious monolithic statues."
Their findings have been published in the journal Neuroscience.