The blood of old people ages young brains, and young – rejuvenates senile

The elixir of youth turned out to be the blood of babies?
CNewsR&D based on an article in Technology Review with a completely opposite title:
Old Blood Impairs Young Brains (Old blood damages young brains)

Experiments on mice conducted by researchers at Stanford University, working under the leadership of Tony Wiss-Corey, have shown that the chemical compounds contained in the blood of aging animals inhibit the formation of new neurons in the young brain. At the same time, young blood is able to give an aging brain a new life.

Scientists came to such conclusions as a result of studying the functioning of the brain of two mice (young and old), whose circulatory systems were surgically connected in the hip area. Such a system of existence of two organisms with a common circulatory system is called parabiosis and is found in nature in Siamese twins.

To study possible behavioral manifestations of the patterns observed in parabiosis, researchers injected young mice with plasma from old animals, and old animals with plasma from young mice. At the same time, as expected, the "old" plasma worsened the abilities of young animals to learn and perform memorization tasks, while the "young" plasma improved the corresponding abilities of old animals.

Parabiosis had a beneficial effect on the brain of an old mouse, this was manifested by the appearance of new neurons (neurogenesis), suppression of inflammatory status and higher synaptic activity. In the brain of a young animal, things were exactly the opposite.

Usually, fewer new neurons appear in the brain of an old animal (left) (dark brown) than at an earlier age. However, the young blood entering the old body noticeably stimulates neurogenesis (right).

Blood cells cannot move into brain tissue, as they are delayed by the so-called blood-brain barrier, so the researchers concluded that the detected effect is due to chemical compounds dissolved in blood plasma. Analysis of 60 chemokines – chemical signals secreted by cells into the blood – revealed several compounds associated with the harmful effects of the blood of old animals. The introduction of one of them, CCL11, to young mice suppressed neurogenesis and impaired cognitive abilities. Previously, this compound was studied as a possible component of the mechanisms underlying the development of allergic diseases, including asthma, but its effect on neurons remains a mystery today.

The researchers plan to continue studying the specific factors they have identified and the functions they perform. They also emphasize that blood is a much more accessible material for analysis than brain tissue, so these factors can be used as biomarkers of neurogenesis and other parameters of the state of the central nervous system.

(Article by Villeda et al. The aging systemic milieu negatively regulates neurogenesis and cognitive function published in the journal Nature 01.09.2011 – WM.)

Portal "Eternal youth" http://vechnayamolodost.ru 01.09.2011