Glymphatic structure and morphological features of the Brain

© 2021 Thieme Medical Publishers, Inc.. All rights reserved.Introduction: there is limited knowledge about the lymphatic circulatory system of brain. The process in which the solutes pass in the brain parenchyma via the interstitial space has not been fully understood up to now. The glymphatic system, which was discovered in recent years, is a waste-cleaning system using an extra-ordinary perivascular channel system, made of astroglial cells, to expel the dissolvable metabolites and proteins out of the central nervous system (CNS). Interestingly, the glymphatic system works basically while asleep and is generally impaired while awake. The metabolic wastes in the brain are cleaned by moving from the interstitial space to the cerebrospinal space. Studies in recent years have shown that some anatomical pathways in the brain facilitate the mixing of CSF (the cerebrospinal fluid) and ISF (interstitial fluid) and remove the substances solved in ISF in the brain. There are three drainage pathways in the brain; (1) Para-arterial CSF flow pathway, (2) Paravenous ISF clearance pathway, and (3) Trans-parenchymal pathway. The glymphatic cleaning system increasingly gains importance in healing some diseases like brain injury, encephalomyelitis, and Alzheimer's disease (AD). Therefore, intensive efforts have been and are still being devoted to the studies on the glymphatic system