Functional hyperemia drives fluid exchange in the paravascular space
| Autor: | Bruce J. Gluckman, Ravi Teja Kedarasetti, Christina Echagarruga, Patrick J. Drew, Kevin L. Turner, Francesco Costanzo |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
0301 basic medicine
Metabolite Models Neurological Hyperemia Brain tissue lcsh:RC346-429 Subarachnoid Space 03 medical and health sciences Cellular and Molecular Neuroscience chemistry.chemical_compound 0302 clinical medicine Developmental Neuroscience Arteriole medicine.artery Extracellular medicine Fluid dynamics Animals Humans lcsh:Neurology. Diseases of the nervous system Cerebrospinal Fluid 030304 developmental biology 0303 health sciences Research Brain General Medicine Fluid exchange Arterioles 030104 developmental biology medicine.anatomical_structure Lymphatic system Neurology chemistry Functional hyperemia cardiovascular system Subarachnoid space Displacement (fluid) 030217 neurology & neurosurgery Artery Biomedical engineering |
| Zdroj: | Fluids and Barriers of the CNS Fluids and Barriers of the CNS, Vol 17, Iss 1, Pp 1-25 (2020) |
| DOI: | 10.1101/838813 |
| Popis: | Maintaining the ionic and chemical composition of the extracellular spaces in the brain is extremely important for its health and function. However, the brain lacks a conventional lymphatic system to remove metabolic waste. It has been proposed that the fluid movement through the paravascular space (PVS) surrounding penetrating arteries can help remove metabolites from the brain. The dynamics of fluid movement in the PVS and its interaction with arterial dilation and brain mechanics are not well understood. Here, we performed simulations to understand how arterial pulsations and dilations interact with brain deformability to drive fluid flow in the PVS. In simulations with compliant brain tissue, arterial pulsations did not drive appreciable flows in the PVS. In contrast, when the artery dilated with dynamics like those seen during functional hyperemia, there was a marked movement of fluid through the PVS. Our simulations suggest that in addition to its other purposes, functional hyperemia may serve to increase fluid exchange between the PVS and the subarachnoid space, improving the clearance of metabolic waste. We measured displacement of the blood vessels and the brain tissue simultaneously in awake, head-fixed mice using two-photon microscopy. Our measurements show that brain tissue can deform in response to fluid movement in the PVS, as predicted by simulations. The results from our simulations and experiments show that the deformability of the soft brain tissue needs to be accounted for when studying fluid flow and metabolite transport in the brain. |
| Databáze: | OpenAIRE |
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