According to scientists at the Massachusetts Institute of Technology, blood may actually influence nerve function and help to regulate information passing through the brain.
Other studies have shown that changes in blood flow affect the activity of nearby neurons, altering how they transmit signals to each other.
Basing their findings on brain scan studies of the sensory homunculus — the brain's detailed map of body parts such as fingers, toes, arms and legs, Dr. Christopher Moore and his colleagues at MIT's McGovern Institute for Brain research said that their research suggested that blood does something more interesting than just delivering supplies.
"If it does modulate how neurons relay signals, that changes how we think the brain works," the Daily Mail quoted Dr. Moore, as saying. The theory could have implications for brain diseases such as Alzheimer's, schizophrenia, multiple sclerosis and epilepsy, which are caused by changes to the network of blood vessels feeding the brain.
"Most people assume the symptoms of these diseases are a secondary consequence of damage to the neurons. But we think they may also be a causative factor in the disease process and that insight suggests entirely new treatments," Dr. Moore said.
He said a drug that affects blood flow could be developed to provide an alternative treatment for epilepsy. The scientists believe blood flow could affect brain activity in two ways.
Blood contains biochemicals, which may leak out of vessels to affect neurons. Changes in blood volume could alter these chemicals' levels. And they say it is possible that neurons and support cells called glia react to blood vessels expanding and contracting. Blood also influences the temperature of brain tissue, which may further affect neural activity.