Information transfer in microvascular networks.

The adequate and efficient functioning of the circulatory system requires coordination of vessel diameters and of vascular responses to local and remote stimuli. Such coordination implies transfer of information about functional status and demands to all parts of the vascular system. In the peripheral circulation, blood flow must be controlled locally to accommodate spatial variations in demand. This requires information transfer from peripheral vessels to the more proximal vessels that feed and drain them. Principal mechanisms available for this information transfer are hemodynamic coupling, diffusive and convective transport of metabolites, and responses conducted along vessel walls. Current knowledge of these mechanisms is reviewed here. Theoretical models provide a framework for examining how information transfer mechanisms and vascular responses are integrated, so as to provide short-term regulation of blood flow and long-term structural adaptation of microvascular networks.