Twenty Years of Calcium Imaging: Cell Physiology to Dye For

Table 1.

Ca²⁺ Signaling Entities in the Vascular Smooth Muscle Cell

Entity	Time domain	Spatial domain	Signaling function
¹See Figure 2.
Ca²⁺ sparks	1–50 ms (RyR2)	1–5 μm	Vasodilation
Ca²⁺ puffs/waves	50–300 ms (IP3R)	5–25 μm	?
Ca²⁺ waves	(IP3R)	Up to 25 μm	Vasoconstriction
Ca²⁺ oscillations¹		Whole cell	Vasomotion
Ca²⁺ waves	100–300 ms (RyR2, pH)	5μm–whole cell	?
Cytosolic Ca²⁺	Seconds to minutes	Whole cell	Vasoconstriction
Ca²⁺ transient (Action potentials)	1–3 sec	Whole cell, propagating to neighboring cells	?