The brain is a ravenous organ. A three-pound adult human brain consumes about a fifth of the body’s energy, yet it cannot store energy on its own and requires constant nourishment from the cardiovascular system. The organ’s energy needs fluctuate greatly depending on neural activity, and sufficient blood must be delivered to the right place at precisely the right time to ensure healthy brain function.
To meet these ever-shifting demands, a process known as neurovascular coupling rapidly increases blood flow to areas of heightened neural activity. This process is impaired in conditions such as hypertension, diabetes and Alzheimer’s disease, and also serves as the foundation for imaging technologies such as fMRI, which uses blood flow as a readout for brain activity.
