Scientists have gained an insight into how the brain monitors and regulates its blood supply, independent of the body-wide blood pressure control system.
The discovery was made by Professor Alexander Gourine of University College London, UK, and his team. They carried out tests on rats and highlighted a mechanism that protects the brain from blood flow fluctuations in the wider body.
They hope the finding will help create new treatments for hypertension and dementia.
Details appeared in Nature Communications on 9 January. It involves brain glial cells called astrocytes which act as sensors between brain blood vessels and nerve cells controlling the heart and peripheral circulation.
Professor Gourine said: “Our new data identify astrocytes as brain blood flow sensors that are critically important for setting the level of systemic (arterial) blood pressure and in doing so ensure that the brain receives a sufficient amount of oxygen and nutrients to support the uninterrupted operation of the information processing machinery.”
Co-author Professor Julian Paton added: “These astrocyte cells are exquisitely sensitive to reductions in brain blood flow. When blood supply is reduced, they release a chemical signal to nearby nerve cells that raise blood pressure, restoring blood flow to the brain.
“Unfortunately, in pathological conditions this is happening at the expense of generating higher blood pressure in the rest of the body. This suggests that increasing brain blood flow by reducing activity in these blood flow sensing astrocytes may be a way to lower blood pressure in people with hypertension.
It may also be a way to combat migraines and strokes. On the other hand, sensitising these cells may help in conditions of dementia to improve brain blood flow.”
Marina, N. et al. Astrocytes monitor cerebral perfusion and control systemic circulation to maintain brain blood flow. Nature Communications 9 January 2020; doi: 10.1038/s41467-019-13956-y
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