Regulation of blood flow is required to maintain tissue perfusion throughout the body in proportion to metabolic demand. Resistance arterioles, comprised of vascular smooth muscle cells (SMCs), endothelial cells (ECs) and perivascular nerves (PVNs), are the primary site of regulation, with subtle changes in diameter resulting in significant alterations in flow. The main goal of our laboratory is examining the subtle interplay between ECs, SMCs and PVNs using a range of in vivo and in vitro techniques in normal and disease states. We have a particular interest in calcium imaging in the various cells that comprise the arteriolar wall, as calcium is a key second messenger involved in numerous blood flow regulating mechanisms. Using both acetoxymethyl ester-containing or genetically-encoded calcium indicators paired with confocal imaging technology, our group examines how changes in intracellular calcium translates into changes in diameter, and thus blood flow.