A Computational Model of Oxygen Transport in the Cerebrocapillary Levels for Normal and Pathologic Brain Function. Issue 10 (October 2013)

• Record Type: Journal Article
• Authors: Safaeian, Navid; David, Tim
• Is Part Of: Journal of cerebral blood flow & metabolism. Volume 33:Issue 10(2013)
• Page Start: 1633
• Page End: 1641
• Publication Date: 2013-10
• Subjects: computational model -- flow-metabolism coupling -- hypoxia -- ischemia -- OEF -- oxygen transport; Cerebral circulation -- Periodicals; Brain -- Metabolism -- Periodicals; Brain -- Blood-vessels -- Periodicals; Cerebrovascular disease -- Periodicals; 612.824
• DOI: 10.1038/jcbfm.2013.119
• Languages: English
• ISSNs: 0271-678X

Abstract

The oxygen exchange and correlation between the cerebral blood flow (CBF) and cerebral metabolic rate of oxygen consumption (CMRO2 ) in the cortical capillary levels for normal and pathologic brain functions remain the subject of debate. A 3D realistic mesoscale model of the cortical capillary network (non-tree like) is constructed using a random Voronoi tessellation in which each edge represents a capillary segment. The hemodynamics and oxygen transport are numerically simulated in the model, which involves rheological laws in the capillaries, oxygen diffusion, and non-linear binding of oxygen to hemoglobin, respectively. The findings show that the cerebral hypoxia due to a significant decreased perfusion (as can occur in stroke) can be avoided by a moderate reduction in oxygen demand. Oxygen extraction fraction (OEF) can be an important indicator for the brain oxygen metabolism under normal perfusion and misery-perfusion syndrome (leading to ischemia). The results demonstrated that a disproportionately large increase in blood supply is required for a small increase in the oxygen demand, which, in turn, is strongly dependent on the resting OEF. The predicted flow-metabolism coupling in the model supports the experimental studies of spatiotemporal stimulations in humans by positron emission tomography and functional magnetic resonance imaging.