Figure 1. Interplay between spontaneous APs and [Ca²⁺]_i in ESdCs.

Confocal line scan (A) and corresponding F/F₀ plot (B) in a 17 day old ESdC with simultaneous measurement of changes in V_m (C). Spontaneous action potentials (APs) are recorded that correlate in time with Ca²⁺ transients. D: Superposition of Ca²⁺ transients and APs clearly show an increase in [Ca²⁺]_i in the late phase of the diastolic depolarization.