"We hypothesize that blood actively modulates how neurons process information. Many lines of evidence suggest 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," LiveScience quoted lead researcher Christopher Moore, as saying.
He added that his theory has implications for understanding brain diseases such as Alzheimer's, schizophrenia, multiple sclerosis and epilepsy.
"Most people assume the symptoms of these diseases are a secondary consequence of damage to the neurons. But we propose that they may also be a causative factor in the disease process," Moore said.
For example, he said, in epilepsy people often have abnormal blood vessels in the brain region where the seizures occur, and the hypothesis suggests this abnormal flow may induce epileptic onset.
He said that he has a few more theories that could clarify just how blood affects neural activity, based on studies in his lab.
Blood contains diffusible elements that could spill out of blood vessels and affect brain activity, and changes in blood volume could have an effect on the concentrations of these factors, he said.
Moore added that neurons may also react to the mechanical forces applied to them when the blood vessels expand and contract.
Citing another theory, he explained that blood also influences the temperatures of the brain tissue, consequently affecting the activity of the cells.
The study is published in the Journal of Neurophysiology