New scientific research suggests that blood not only delivers oxygen and other supplies to our brain but is actually involved in neuronal activity. According to MIT neuroscientist Christopher Moore, the localized flow of blood can actually affect individual neurons that relay signals in our brains. Someday, his theory, called the Hemo-Neural Hypothesis, could possibly lead to better treatments for diseases like Alzheimer's, schizophrenia, and epilepsy. From the McGovern Institute for Brain Research:
How could blood flow affect brain activity? Blood contains diffusible factors that could leak out of vessels to affect neural activity, and changes to blood volume could affect the concentration of these factors. Also, neurons and support cells called glia may react to the mechanical forces of blood vessels expanding and contracting. In addition, blood influences the temperature of brain tissue, which affects neural activity.Link
To Moore's knowledge, the Hemo-Neural Hypothesis offers an entirely new way of looking at the brain. "No one ever includes blood flow in models of information processing in the brain," he said. One historical exception is the philosopher Aristotle, who thought the circulatory system was responsible for thoughts and emotions. Perhaps the ancient Greeks were on to something.