Penn State researchers have found that the signal of global brain activity is coupled to movement of cerebral spinal fluid in humans. It appears that the coupled movement cleans out the brain’s toxins as a person sleeps. The weaker the coupled movement, the higher the risk the person could develop Alzheimer’s disease. The signal can viewed via non-invasive brain imaging and could serve as a clinical marker to help in diagnosis.
Penn State College of Engineering
First described in 2012, the glymphatic system acts as a waste management system, washing out the proteins and other buildup that can hinder brain activity. The critical component of the system is the cerebrospinal fluid flow, according to Liu, which his research suggests is activated by the global BOLD signal activation. In sleep, the glymphatic system can speed up its cleaning processes significantly.