Figure 3.
Pseudo-color fluorescent images of a typical intercellular calcium signaling process in an MC3T3-E1 cell network (untreated group, ordered in time sequence). This specific test was selected from the 90 nN loading group due to its dramatic [Ca2+]i oscillations. (A) All the cells showed similar free [Ca2+]i intensity before stimulation. (B) The cell in the center was mechanically stimulated by an AFM indentation probe. It released a robust calcium spike that reached its peak magnitude in a short time. (C) The calcium signal was propagated to the four neighboring cells (cell II). All cell II showed calcium responses but reached their peak at different time points. (D) The cells two steps away from the indented cell (cell III) showed relatively weaker [Ca2+]i spikes, while the [Ca2+]i intensity of the indented cell and cell II have decreased toward to their original levels.