Nature is absolutely not trying to cause any panic with news that injecting baby brain cells into older mice keep them younger and healthier longer:
Previous studies have suggested that the hypothalamus is involved in ageing, but the latest research shows that stem cells in this region can slow the process. That makes sense, because the hypothalamus is involved in many bodily functions, including inflammation and appetite, says Dongsheng Cai, a neuroendocrinologist at Albert Einstein College of Medicine in New York City.
In their study, Cai and his colleagues found that stem cells in the hypothalamus disappear as mice grow older. When the researchers injected their mice with viruses that destroy these cells, the animals seemed to grow older faster, experiencing declines in memory, muscle strength, endurance and coordination. They also died sooner than untreated mice of the same age.
Next, the team injected stem cells taken from the hypothalami of newborn mice into the brains of middle-aged mice. After four months, these animals had better cognitive and muscular function than untreated mice of the same age. They also lived about 10% longer, on average.
The researchers found that these stem cells release molecules called microRNAs, which help to regulate gene expression, into the cerebrospinal fluid. When the team injected these microRNAs into the brains of middle-aged mice, they found that the molecules slowed cognitive decline and muscle degeneration.