The differential hypothesis: a provocative rationalization of the conducted vasomotor response

Abstract

Tissue blood flow is controlled by a branching network of resistance arteries coupled in series and parallel with one another. To alter organ perfusion during periods of elevated metabolic demand, the arterial segments comprising these networks must dilate in a coordinated manner. Gap junctions are intercellular pores that facilitate arterial coordination by enabling electrical stimuli to conduct among and between endothelial and/or smooth muscle cells. Through this novel perspective, readers will be introduced to the vascular communication field, the process of intercellular conduction, and how key cellular properties influence charge flow. This overview will begin with a brief historical review and then introduce two differing theories on how electrical phenomena moves among and between vascular cells. The basis of the "syncytium" and "differential" hypothesis will be critically discussed within a framework of biophysical and experimental observations. This foundational understanding will be used to extend our mechanistic insight of: (i) "local" and "global" blood flow control; and (ii) debilitating disorders such as arterial vasospasm.