Can diffusion alone explain brain-wide distribution of a CSF tracer within 24 hours?

Autor: Valnes, Lars Magnus, Mitusch, Sebastian K., Ringstad, Geir, Eide, Per Kristian, Funke, Simon W., Mardal, Kent-Andre
Jazyk: angličtina
Rok vydání: 2019
Předmět:
DOI: 10.13140/rg.2.2.26588.54404
Popis: The recently proposed glymphatic system suggests that bulk flow is important for clearing waste from the brain, and as such may underlie the development of e.g. Alzheimer's disease. The glymphatic hypothesis is still controversial and several biomechanical modeling studies at the micro-level have at least partially dismissed the system and its assumptions. In contrast, at the macro-level, there are many experimental findings in support of bulk flow. Here, we will investigate to what extent the CSF tracer distributions seen in novel magnetic resonance imaging (MRI) investigations over hours and days are suggestive of bulk flow or diffusion. In order to include the complex geometry of the brain, the heterogeneous CSF flow around the brain, and the transport over the time-scale of days, we employed the methods of partial differential constrained optimization to identify the apparent diffusion coefficient (ADC) that would correspond best to the MRI findings. We found that the computed ADC in grey and white matter was respectively 23\% and 82\% larger than the ADC estimated with DTI, which suggests that diffusion may not be the only mechanism governing transport.
Comment: 20 pages, with 6 pages supplementary, 13 figures
Databáze: OpenAIRE