How calcium directs the blood flow in the brain’s capillaries

As part of a recent study first published in Science Advances, a group of experts at the University of Maryland, in conjunction with the University of Vermont, attempted to further comprehend how the brain communicates to blood vessels when energy is needed.

The study also looked at how the brain directs energy to itself and what outcomes can occur if blood flow in the brain is disrupted, leading to neurodegeneration.

“There seem to be two mechanisms working in tandem to ensure that energy in the form of blood makes it to specific regions of the brain: one broad and the other precise,” said Thomas Longden, co-author of the study, in a press release.

“The first electrical mechanism is like a crude sledgehammer approach to get more blood to the general vicinity of the increased brain activity by controlling the medium-sized arterioles, and then capillary calcium signals ensure exquisite fine-tuning to make sure the blood gets to exactly the right place at the right time through the tiny capillaries.”

For the study, researchers turned to calcium signaling in the brain within the brain’s blood vessels. In rodents, they probed calcium’s role in controlling blood flow in the brain’s capillaries.

By using a protein that emits a green light when calcium increases in the cell, researchers were able to detect 5,000 calcium signals per second in the capillaries in the tiny section of the brain visible, purportedly attributed to nearly 1 million of these responses each second in the brain’s whole blood vessel system.

The study showed that calcium directs blood flow in the brain’s blood vessels.

“Capillaries were traditionally thought as simple conduits for red blood cells, and the barrier between the blood and brain,” said Mark Nelson, another co-author of the study.

“Here, we revealed an unknown universe of calcium signaling in capillaries, and much like traffic lights, these calcium signals direct vital nutrients to nearby active neurons.”

Image courtesy of zhihu