Two recent animal discoveries may someday help humans lead longer, better lives.
One study shows that aging honeybees can regain the brainpower of youth. In the other, a so-called Easter Island drug enhanced the memories of laboratory mice.
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The bee study, published in May by the journal Experimental Gerontology, looked at the different capabilities of young and old members in a colony.
Researchers removed the young, "nurser" bees from the hive. Older bees—which exhibit "age-associated learning deficits" toward the end of their six-week life expectancy—took on the nursing responsibilities they had fulfilled earlier in life, for example secreting "royal jelly" for larvae.
Study leader Nicholas Baker of the Arizona State University School of Life Sciences reported that many of the older bees "were performing as well as the young nurser bees had. We were like, They're intelligent again! So what happened?"
But not all of the older bees were competent nurses.
Analyzing the "intelligent again" bees and the poorer-performing ones, the researchers found higher levels of the protein glutamate in brains of the bees the experiment was successful on. In humans, moderate levels of glutamate can be helpful for memory and learning, although too much can harm higher cognitive functions.
The study concluded that glutamate can rebuild bee brain cells—and that the old bees lived longer than they would have otherwise after resuming their nursing duties.
That's good news for bees, and perhaps for people, too.
"With people, you can't reverse that clock," Baker said. "But this does show that social contact, and taking on new activities, building new brain connections, delays the bad effects of aging."
The study could lead to other benefits.
By studying the protein changes in the honeybee brains, scientists hope to design drugs that could help fight off the decreased brain function associated with aging.
It could take 30 years before such drugs are ready, Baker said. In the meantime, he advises older people to tackle fresh challenges as a way to stay young.
(Also see "Anti-Aging Drug for Humans Hinted at by Worm Study.")
An Antiaging Drug for Mice ... and People?
As for those rodents: Researchers at the University of Texas Health Science Center have discovered a drug that reduces memory loss in elderly mice, acts as a antidepressant, and actually extends lifespan.
Their study, released by Neuroscience on June 28, tested the efficacy of Rapamycin, a drug derived from soil found on Easter Island (map), or Rapa Nui. Though Rapamycin has been used for years to facilitate organ transplantation, researchers have only recently begun testing its antiaging properties.
In this study, the mice given Rapamycin showed signs of enhanced memory, decreased anxiety and depression, and overall longer life.
Initially, the plan was to give Rapamycin to two groups of mice, one affected by Alzheimer's and a control group. Researchers soon found that all the mice, even the healthy ones, exhibited an upswing in mood, according to the study, co-authored by physiologist Veronica Galvan.
Researchers explain that Rapamycin inhibits a protein that dictates whether a cell will decide to grow or go into "maintenance mode," which is linked to a longer life.
The next step is to put the drug to the test on humans. Galvan hopes for clinical trials in another five years.