Brain blood flow sensor discovery could aid treatments for dementia

Researchers at UCL have discovered the mechanism that allows the brain to monitor its own blood supply, a finding in rats which may help to find new treatments for conditions including hypertension (high blood pressure) and dementia. For decades, scientists have suspected that the brain had a way of monitoring and regulating its own blood flow separate from the body-wide blood pressure control system, but until now no one had proven this. The brain needs more blood than any other organ to satisfy neurons' relentless, high demand for oxygen, so it makes sense that it would have a way of buffering itself from blood flow fluctuations in the wider body. Disturbances to brain blood flow are a known cause in many diseases - for example, sustained reduction in brain blood flow is a likely cause of cognitive decline, dementia, and neurodegenerative disease such as Alzheimer's disease. In a study published in Nature Communication s, researchers from UCL, the University of Auckland and Bristol University, found a new function for the star-shaped brain glial cells, known as astrocytes. These cells function as specialised brain blood flow sensors that operate to self-protect the brain from potentially damaging reductions in blood supply. Astrocytes are strategically positioned between the brain blood vessels and important nerve cells, which control the heart and peripheral circulation, ultimately determining the arterial blood pressure.