This bump in blood flow is a way the brain ensures that highly active neurons get enough blood, and the oxygen and nutrients it carries, says Dr. Philip O'Herron, neurovascular physiologist in the Department of Physiology at the Medical College of Georgia at Augusta University.
It's called functional hyperemia and it's a regular occurrence that appears to also help the brain better target it's use of "expensive" blood, says O'Herron.
Brain - Lot - Energy - Neurons - Energy
"The brain consumes a lot of energy, but when neurons are activated they consume more energy than when they are silent," O'Herron says. "The increase in blood flow needed to provide that energy is pretty small -- often only a few percent increase -- compared to the amount of blood already there."
But even the small increase can look a bit like overkill to scientists like O'Herron exploring the brain's physiology. He's among the scientists who've seen how not only are the activated neurons getting more blood and oxygen, but so is nearby tissue that has no clear involvement. It appears that even the firing brain cells are getting more than needed since oxygen levels in the blood remain higher than the norm past the point of action.
O'Herron - Exploratory/Developmental - Research - Grant - National
O'Herron has received a two-year, $420,000 Exploratory/Developmental Research Grant from the National Institutes of Health that is enabling him to learn more about this natural, common response, including how neural activity drives blood flow increases, how important the increases are for the health and proper functioning of neurons and whether there really is overkill.
Benefits of better understanding could include better interpreting results of decades-old imaging technology called functional MRI, or fMRI, which is based on the premise that increased neural activity affects blood and oxygen flow to that region and is currently used to explore problems like brain tumors and epilepsy. It could also begin to...
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