A computerized video microscope system will be used to digitize, store and reconstruct complete microvascular networks in the cerebral cortex of the rat in vitro. A mathematical model of cerebral microcirculation based on the reconstructed course, branching pattern and diameter of the vessels and a model of apparent blood viscosity will be developed. The model will be used for a computer simulation of vascular growth and adaptation to mechanical strain and changing blood flow representing growth of or injury to brain tissue and/or a change in local tissue metabolism. The cerebral microcirculation plays a critical role in the maintenance of an optimum internal environment for neuronal function. The response and adaptation of microvascular architecture and blood flow to mechanical and biochemical stimuli from normal or injured nervous tissue is, however, poorly understood. A computer simulation of cerebral microvascular growth based on real vascular architecture and geometry is developed to study possible mechanical/hemodynamic determinants of microvascular reorganization. Until now, the measurement and modeling of the essentially 3-dimensional cerebrovascular architecture has been essentially impossible. Using novel methods of computerized video microscopy, the true 3-dimensional Topological and geometrical organization of complete microvascular networks of the brain cortex can be determined for the first time. This allows the engineering analysis of distribution of blood flow in the reconstructed microvascular system and, in turn, the computer simulation of the adaptive growth of vascular tissue in response to mechanical and functional stimuli.
