Fig. 1.

Calcium responses of HL-1 cells in HBSS + Ca²⁺ after laser stimulation with different radiant exposures and irradiation times for the three considered regions. (a): Distribution of cells within the laser spot (red selection), at the periphery of the laser spot (orange selection) and outside of the laser spot (yellow selection) with the laser spot being marked green. Scale bar: 40 µm. (b): Relative frequency of occurrence of the three different calcium responses shown in HL-1 cells in HBSS + Ca²⁺ buffer after laser stimulation of cells within the laser spot (top), at the periphery of the laser spot (middle) and outside of the laser spot (bottom). Accumulated over all three areas, calcium oscillations occurred most frequently with a radiant exposure of 15 mJ/cm² and 20 ms irradiation time. Data represents the mean + SEM of at least n = 10 irradiated cells.