Glymphatic Brain Clearing (Lymphatics)
The glymphatic system is a recently discovered macroscopic waste clearance system that utilizes a unique system of perivascular tunnels, formed by astroglial cells, to promote efficient elimination of soluble proteins and metabolites from the central nervous system.
Besides waste elimination, the glymphatic system also facilitates brain-wide distribution of several compounds, including glucose, lipids, amino acids, growth factors, and neuromodulators. Intriguingly, the glymphatic system function mainly during sleep and is largely disengaged during wakefulness. The biological need for sleep across all species may therefore reflect that the brain must enter a state of activity that enables elimination of potentially neurotoxic waste products, including β-amyloid. Since the concept of the glymphatic system is relatively new, we will here review its basic structural elements, organization, regulation, and functions. We will also discuss recent studies indicating that glymphatic function is suppressed in various diseases and that failure of glymphatic function in turn might contribute to pathology in neurodegenerative disorders, traumatic brain injury and stroke.
Anterior intercavernous sinus
Beta amyloid clearance as needed
Central nervous system
Clear extracellular solutes as needed
Clearance mechanisms work well
Create optimal sleep conditions
Deep delta waves for maximum glymphatic function
Glial cells optimal function
Interior saggital sinus
Internal cerebral vein
Maximal drainage of glymphatic system
Meningeal lymphatic system optimized