Brain’s Blood Flow Regulation Linked to Glucose Levels

Researchers at the University of Maryland School of Medicine have discovered a new mechanism by which the brain regulates its blood flow in response to changes in glucose levels. The study, published in the journal Cell Reports, shows that pericytes, cells located outside the brain’s smallest blood vessels, sense when their brain region needs more energy. When glucose levels are low, these cells signal blood vessels to dilate, increasing the blood flow regionally and allowing more energy to fuel that part of the brain.

“These fluctuations in blood flow help direct the brain’s energy resources to support everyday functions,” said study leader Thomas Longden, Ph.D., Assistant Professor of Physiology at UMSOM. “As I am speaking now, the blood flow in my brain will be diverted to the language areas and the motor (or movement) areas that control my vocal cords to fuel these processes.”

This process, known as electro-metabolic signaling, is vital to ensure that adequate energy is supplied to the brain’s neurons in a timely manner. If there is a mismatch of energy supply and demand, it can cause the brain’s neurons to undergo stress, leading to impaired protein metabolism, alterations in neuronal firing, and eventually, cell death.

In 2022, Dr. Longden’s laboratory published a paper in Science Advances showing that signals in the form of calcium—shaped by electrical impulses through the blood vessels—cause certain brain capillaries to relax, controlling blood flow. In their newest study, his team demonstrated that a specific type of cell outside the capillaries, known as pericytes, directs these electrical pulses based on their perception of local energy needs.

This energetic failure in blood vessel function of the brain has been shown to occur during the aging process, in certain neurodegenerative diseases, like Alzheimer’s, and in stroke,” says Dean of UMSOM Mark T. Gladwin, MD, Vice President for Medical Affairs, University of Maryland, Baltimore, and the John Z. and Akiko K. Bowers Distinguished Professor.

Dr. Longden adds, “By studying how this process functions normally, researchers may be able to gain further insight into what happens in aging or in neurodegenerative diseases, so they can develop better therapies.”