The US team identified the mechanism in the hypothalamus. It sits deep inside the brain. They found that they could tweak it to shorten or lengthen the lives of animals like mice.
After multiple experiments, the researchers found they could extend the lives of mice by one fifth, without the animals suffering from the common muscle weakness, bone loss, or memory problems.
The work raises the tantalizing prospect of drugs that could slow down natural ageing to prolong life
in humans, but more importantly it these new drugs could prevent age-related diseases, such as diabetes, heart disease, and Alzheimer's.
Dongsheng Cai at the Albert Einstein College of Medicine in New York told the Guardian. "We're very excited about this. It supports the idea that ageing is more than a passive deterioration of different tissues. It is under control, and can be manipulated,"
The scientists said that they found that a chemical called NF-kB became more active in the hypothalamus of mice as they got older. When the researchers blocked the substance, mice lived up to 1,100 days, compared with 600 to 1000 days for normal healthy mice. When they boosted NF-kB in mice, they all died within 900 days. Without the NF-KB the mice had more muscle and bone, were better at learning, and had healthier skin than the controls.Further work showed that NF-kB lowered levels of a hormone called GnRH, which is better known for the central role it plays in fertility and the development of sperm and eggs. When the scientists gave old mice daily jabs of GnRH, they found this too extended the animals' lives, and even caused fresh neurons to grow in their brains.
"The idea that ageing can be globally influenced by hormones produced in the brain is of great interest to scientists," Yankner told the Guardian. "Given the many effects of these hormones, however, their clinical use in diseases of ageing, such as diabetes, Alzheimer's and heart disease, will need to be carefully studied," he said.
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