THE GLYMPHATIC SYSTEM OF THE BRAIN: ESSENCE AND CONTEMPORARY IMPLICATION OF NEWLY DISCOVERED TREASURE

Abstract

Full Text

The Glymphatic System (GS) is a novel concept of intrinsic brain drainage implying continuous convective flow or diffusion of interstitial fluid (ISF) through peri- or/and paravascular pathway. Until 2012 this anatomical and physiological phenomenon had been unfathomable due to the GS lacks proper vessels for ISF efflux from brain parenchyma - ISF passes inside or next to the walls of cerebral arteries and veins. Modern advances in biorheology have revealed a key role of astrocytic aquaporin-4 channels in ISF filtration. As this pathway is too narrow for immune cells, the GS can be considered as a major factor in the immune privilege of the CNS. The discovery of this novel system contributing brain homeostasis gives some insight into pathogenesis of various neurodegenerative disorders and propels new therapeutic approaches in their treatment. Likewise, some scientists believe the GS disorders are central to progression of normal pressure hydrocephalus. One of the most efficient methods to eliminate neurotoxic metabolites as well as reduce intracranial pressure implies usage of manual lymphatic mapping. Overall, thorough glymphatic drainage is crucial for maintaining optimal neuronal microenvironment thus providing proper brain functioning.