Fig. 2

Spontaneous Ca²⁺ transients recorded from beating ACMs. a Changes in [Ca²⁺]_i in the fluo 4-loaded beating ACMs recorded by confocal line-scan imaging. Cultured for 6 days. White line on the cell image indicates the scanned line (upper left). Representative traces show the fluorescent time course at the site marked by the arrows on the line-scan images (upper right of each trace). The cells were perfused with normal Tyrode solution (control) and then were subsequently exposed to 10⁻⁶ M isoproterenol. b Peak intervals of the spontaneous Ca²⁺ transients detected in ACMs before (control) and after exposure to isoproterenol (n = 5 cells, paired experiments). *p < 0.05