Browsing by Subject "brain clearance"

Abstract Faculty: Faculty of Biological and Environmental Sciences Degree programme: Master’s programme in Neuroscience Study track: Neuroscience Author: Enija Stoka Title: The Role of Meningeal Lymphatic Vessels in the CNS clearance Level: Master’s thesis Month and year: April 2022 Number of pages: 28 Keywords: meningeal lymphatic vessels (mLVs), brain clearance, glymphatic system, perivascular spaces Supervisor or supervisors: Anaϊs Virenque, Francesco Mattia Noe Where deposited: the Helsinki University Library Additional information: - Abstract: The lymphatic system is a drainage pathway for metabolic waste products, soluble proteins and cerebro-spinal (CSF) as well as interstitial (ISF) fluids. Classically, the lymphatic system has been described all over the body, except the central nervous system (CNS) and the retina. This fact created the question of how the brain is being cleared from harmful solutes. The first system described to being responsible for the clearance of the brain was the glymphatic system, and only recently the existence of lymphatic vessels in the meninges (the meningeal lymphatic vessels, mLVs), has been recognized. However, it is still unknown how these two systems interact in removing solutes from the brain. Here, we analyse if the absence of mLVs affects diffusion and clearance of two tracers with low and high molecular weight (3 kDa and 70 kDa), which have been injected intraparenchymally in wild type (WT) and transgenic (TG) mice lacking functional mLVs. Diffusion of 3 kDa dextran tracer in the surrounding tissue was noticeably increased in WT compared to TG mice, associated with an overall decreased accumulation of the tracer in the parenchyma of the mice lacking mLVs. At the same time, we did not observe a genotype difference in the diffusion or clearance of the 70 kDa dextran tracer. Overall, these results indicate that mLVs dysfunction affects the intraparenchymal diffusion and clearance of low molecular weight molecules.