The brain decides how much to live

The hypothalamus, a nucleus of neurons the size of an almond that all vertebrates have in the base of the brain is the control center that regulates aging and longevity of an organism. This is demonstrated by an investigation of the Albert Einstein School of Medicine in New York presented in the journal Nature that represents a paradigm shift in the understanding of aging. The authors propose research strategies to prevent health problems resulting from aging and increase longevity.

In experiments with rats, these strategies have allowed longer life by about 20%. They have prevented neuronal loss characteristic of the aging and maintenance of good learning capacity until later. If these results can be extrapolated into the future of the human species, it would mean that people of 90 years could be as good health as they are currently 75.

How is it possible that different organs and body systems wear out in a coordinated manner?, Researchers wondered. And how is it possible for a species like hamsters on growth, reproduction and generational change are completed in two years, while others like some turtles can reach two hundred? One possible answer is that there is a control center somewhere in the brain that regulates the life cycle of the species and aging orchestrate coordinated various body parts.

In previous studies, researchers at the Albert Einstein School of Medicine have focused on the effects of inflammation in the brain. Inflammation, in medicine, refers not only to acute reaction to swelling, redness and pain that occurs, for example, in the area of ​​a wound. It also refers to a reaction less visible but more persistent in the immune system tries to protect the body from assault but ends up causing more damage than it prevents. Chronic inflammation, as assaults favored by excess calories in the diet or toxic snuff increases the risk of age-related diseases including cardiovascular disease, Alzheimer’s, type 2 diabetes or certain cancers.

Cai and his team have discovered that inflammation affects the hypothalamus and this, in turn, increases the risk of metabolic syndrome, a combination of disorders usually include hypertension, excess abdominal fat, cholesterol and poorly excess sugar control blood, all cardiovascular risk factors which tend to increase with age.

In analyzing what exactly happens when the hypothalamus receives signals from inflammation, researchers have now identified NF-KB proteins as key pieces of the plot. These proteins, discovered 27 years ago, are rising stars in molecular biology. With multiple functions in the body, are involved in a large number of cancers, autoimmune diseases and defense against infections, radiation or free radicals.

In contrast, blocking the activity of NF-KB in the hypothalamus had the opposite effect slowed aging and lengthen the lives of mice by 20%.  In subsequent experiments, the researchers showed that NF-kB exerts its action on aging through hormone GnRH (full name: gonadotropin releasing hormone). These two substances are regulated between them like a seesaw: when NF-KB rises, falls and vice versa GnRH. The researchers found that the decrease of GnRH in the hypothalamus accelerates aging. But in one of the most spectacular results of the investigation, the animals that were administered the hormone in the hypothalamus stopped losing neurons with age and kept intact their ability to learn.

GnRH, moreover, plays a central role in reproduction. It depends, for example, regulation of the menstrual cycle in women and sperm formation in men. By linking aging with GnRH, so the researchers propose a mechanism to explain how it regulates the life cycle of the species, from two years of hamsters to a few hundred turtles.

In the same vein, researchers Dana Gabuzda and Bruce Yankner, of Harvard Medical School (USA) written in Nature that concluded that the aging inflammation is due to the integration of immune and hormonal responses in The hypothalamus is a new paradigm.
Apart from theoretical advance science posed to aging, new findings also open the way for practical applications. One option would be to explore hormonal therapy to restore the levels of GnRH in the hypothalamus. The other search immune therapy to inhibit inflammation reaction that increases the amount of NF-KB. In anticipation of developing safe and effective drugs to achieve this aim, says Cai, chronic inflammation can be kept at bay with healthy lifestyle to avoid excess calories in the diet and other environmental insults.

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