Pulsations with reflected boundary waves: a hydrodynamic reverse transport mechanism for perivascular drainage in the brain

J Math Biol. 2016 Aug;73(2):469-90. doi: 10.1007/s00285-015-0960-6. Epub 2016 Jan 4.

Abstract

Beta-amyloid accumulation within arterial walls in cerebral amyloid angiopathy is associated with the onset of Alzheimer's disease. However, the mechanism of beta-amyloid clearance along peri-arterial pathways in the brain is not well understood. In this study, we investigate a transport mechanism in the arterial basement membrane consisting of forward-propagating waves and their reflections. The arterial basement membrane is modeled as a periodically deforming annulus filled with an incompressible single-phase Newtonian fluid. A reverse flow, which has been suggested in literature as a beta-amyloid clearance pathway, can be induced by the motion of reflected boundary waves along the annular walls. The wave amplitude and the volume of the annular region govern the flow magnitude and may have important implications for an aging brain. Magnitudes of transport obtained from control volume analysis and numerical solutions of the Navier-Stokes equations are presented.

Keywords: Alzheimer’s disease; Interstitial fluid flow; Perivascular transport.

MeSH terms

  • Alzheimer Disease / physiopathology*
  • Amyloid beta-Peptides / metabolism
  • Arteries / metabolism
  • Brain / blood supply*
  • Cerebral Amyloid Angiopathy / physiopathology
  • Drainage
  • Humans
  • Hydrodynamics
  • Models, Biological*

Substances

  • Amyloid beta-Peptides