Research into understanding the effects of blood flow on the brain has come to a head this week, with scientists discovering that brain blood flow affects certain serious illnesses such as high blood pressure, migraines and dementia.
Academics from the University of Auckland, University College London and Bristol University have discovered that the brain has its own blood pressure sensors that monitor and regulate blood flow, separate from the body-wide blood pressure control system.
Due to the brain needing more blood than any other organ, disturbances to brain blood flow are a known cause for many diseases. For example, a likely cause of cognitive decline and diseases such as dementia and Alzheimer’s is a prolonged reduction to brain blood flow.
While conducting an animal study, researchers found the sensors, tiny cells called astrocytes, strategically squeezed between blood vessels and nerve cells in rats’ brains. When stimulated, these cells increased blood flow into the brain.
“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,” said Professor Julian Paton, from the University of Auckland’s Faculty of Medical and Health Sciences.
“What we have discovered is that the brain has an automatic way to make sure that brain blood flow is preserved. Unfortunately, in pathological conditions, this is happening at the expense of generating higher blood pressure in the rest of the body,” he said.
The researchers say that this knowledge could have serious implications into how we treat neurological diseases.
Professor Alexander Gourine from the University College London says they are very excited about the discovery because there has never been a formal description of a blood flow or blood pressure sensor within the brain before. “Our new data identify astrocytes as brain blood flow sensors that are critically important for setting the normal level of systemic (arterial) blood pressure and in doing so ensures that the brain receives a sufficient amount of oxygen and nutrients to support the uninterrupted operation of the information processing machinery,” he said.
From Aged Care Insite.