Fig. 1. Amplitude dependency of PRCs at the cellular and population levels.

a Models of circadian rhythm and phase response at the cellular and population levels. b Mathematical models for PRC at the single cell and population levels. c Mathematical models for amplitude response curve at the single cell and population levels. PRCs for forskolin, PMA, and NaHCO₃ at the single cell (d) and population levels (e). At the population level, one sample contains five cells, which are randomly selected. Concentrations of forskolin, PMA, and NaHCO₃ were 0.75 μM, 2 μM, and 77.75 mM for single-cell PRCs and 0.5 μM, 1 μM and 66.5 mM for population PRCs, respectively. In single-cellular PRCs, an amplitude of A > 0.6 was defined as high amplitude, while A < 0.4 was considered low amplitude. In population PRCs, an amplitude (synchronization index) of R > 0.8 was defined as synchronized, while R < 0.1 was considered desynchronized.