Scientists slow down ageing in mice

Scientists claim to have found the "fountain of ageing" in the shape of hypothalamus - a small region of the brain - which they say holds key to slowing down the rate of ageing.
The almond-sized structure in the brain is involved in regulating the secretion of various hormones.
For the first time, scientists at Albert Einstein College of Medicine of Yeshiva University report that the hypothalamus of mice controls ageing throughout the body.
"It's clear from our study that many aspects of ageing are controlled by the hypothalamus. What's exciting is that it's possible - at least in mice - to alter signalling within the hypothalamus to slow down the ageing process and increase longevity," said senior author Dongsheng Cai, professor of molecular pharmacology at Einstein.

The hypothalamus is known to have fundamental roles in growth, development, reproduction, and metabolism. Cai suspected that the hypothalamus might also play a key role in ageing through the influence it exerts throughout the body.
To find out how the hypothalamus might affect ageing, Cai decided to study hypothalamic inflammation by focusing on a protein complex called NF-kB (nuclear factor kappa-light-chain-enhancer of activated B cells).

"Inflammation involves hundreds of molecules, and NF-kB sits right at the center of that regulatory map," he said.
Cai and his team demonstrated that activating the NF-kB pathway in the hypothalamus of mice significantly accelerated the development of ageing, as shown by various physiological, cognitive, and behavioural tests.

"The mice showed a decrease in muscle strength and size, in skin thickness, and in their ability to learn - all indicators of ageing. Activating this pathway promoted systemic ageing that shortened the lifespan," he said.
Conversely, Cai and his group found that blocking the NF-kB pathway in the hypothalamus of mouse brains slowed ageing and increased median longevity by about 20 per cent, compared to controls.
The researchers also found that activating the NF-kB pathway in the hypothalamus caused declines in levels of gonadotropin-releasing hormone (GnRH), which is synthesised in the hypothalamus.
Release of GnRH into the blood is usually associated with reproduction.

When aged mice received daily GnRH injections for a prolonged period, this therapy exerted benefits that included the slowing of age-related cognitive decline, probably the result of neurogenesis.
The study was published in the journal Nature.