||P.1120 caption to figure 10: "Functional triads responsible for the generation of local high Ca2+ transients and catecholamine secretion in chromaffin cells. The voltage-dependent calcium channel (VOCC), the Ca2+ uniporter (U) from the surrounding mitochondria, the ryanodine receptor (RyR) from the endoplasmic reticulum, and the secretory vesicle are all strategically located beneath the plasma membrane. Ca2+ entry through the VOCC triggers Ca2+-induced Ca2+ release from the RyR and generates a local [Ca2+]c microdomain of ∼50 μM. In the rest of the cell, the [Ca2+]c increase was much smaller, ∼1 μM. The mitochondrion, located far away from the high Ca2+ microdomain, increases its [Ca2+]M only to ∼2 μM. [From Montero et al. (primary source).]"