Figure 5. Heterogeneous response of SCN cells to the increasing concentration of fluo-4 AM in rat slice cultures of SCN:

The dependency of spontaneous [Ca²⁺]_c spiking activity on the concentration (0.5–10 µM) of fluo-4 AM was examined. The mean frequency of calcium spikes was gradually increased in about 49% (A–B) of the active populations, had no systematic change in 35% (C–D), and decreased in 16% (E–F). The red crosses mark the peak positions. All error bars represent a standard error. The data were collected from a total of 76 active cells in 3 different slices. A, C, and E are three representative cases corresponding to the three different subpopulations.