A control mechanism for intramural periarterial drainage via astrocytes: How neuronal activity could improve waste clearance from the brain

The onset and development of Alzheimer’s disease (AD) is closely associated with the failure to eliminate waste from the brain [1]. The mechanisms behind this waste clearance remain largely unclear, however research suggests a strong link with the cerebral vasculature [2, 3]. Here we demonstrate computational evidence for a mechanism for cerebral waste clearance that is driven by functional hyperaemia, that is, the dilation of cerebral arteries as a consequence of increased neuronal demand. This mechanism is based on our model for fluid flow through the vascular basement membrane [4]. It accounts for waste clearance rates observed in mouse experiments and aligns with pathological observations as well as recommendations to lower the individual risk of AD, such as keeping mentally and physically active.