Surface periarterial spaces of the mouse brain are open, not porous
Surface periarterial spaces of the mouse brain are open, not porous
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DOI：
10.1098/rsif.2020.0593
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发表时间：
2020-11-25
影响因子：
3.9
通讯作者：
Kelley, Douglas H.
中科院分区：
文献类型：
--
作者：
Rivas, Fatima Min;Liu, Jia;Kelley, Douglas H.
脑脊液在大脑中流动的流体动力学模型将血管周围空间视为开放的(没有内部固体障碍)或多孔的。在这里，我们提出了实验证据，证明小鼠的软脑膜(表面)动脉周围空间基本上是开放的。(1)血管周围空间中颗粒的路径是光滑的，正如在开放的血管中粘性流动所预期的那样，而不是像在多孔介质中流动所预期的那样扩散。(2)动脉周围空间的时间平均速度分布与现实模型中粘性流动的理论分布非常接近，但与多孔介质所期望的近乎均匀的分布不一致。因为这些空间是开放的，所以它们的水力阻力比多孔的要小得多。为了证明，我们计算了现实的动脉周围空间的水力阻力，包括开放的和多孔的，并表明多孔空间的阻力更大，通常是100倍或更多。这些动脉周围空间的开放性质允许更大的流速和更有效地清除代谢废物。
Fluid-dynamic models of the flow of cerebrospinal fluid in the brain have treated the perivascular spaces either as open (without internal solid obstacles) or as porous. Here, we present experimental evidence that pial (surface) periarterial spaces in mice are essentially open. (1) Paths of particles in the perivascular spaces are smooth, as expected for viscous flow in an open vessel, not diffusive, as expected for flow in a porous medium. (2) Time-averaged velocity profiles in periarterial spaces agree closely with theoretical profiles for viscous flow in realistic models, but not with the nearly uniform profiles expected for porous medium. Because these spaces are open, they have much lower hydraulic resistance than if they were porous. To demonstrate, we compute hydraulic resistance for realistic periarterial spaces, both open and porous, and show that the resistance of the porous spaces are greater, typically by a factor of a hundred or more. The open nature of these periarterial spaces allows significantly greater flow rates and more efficient removal of metabolic waste products.