Synchronization-Induced Rhythmicity of Circadian Oscillators in the Suprachiasmatic Nucleus
Figure 7
Simulation of Entrainment of a 2-D SCN Slice by a 12:12 LD Cycle
(A) Simulation of the evolution of Per/Cry mRNA over 48 h of 309 coupled cells (VL, n = 102; DM, n = 207) in a 2-D SCN slice with a type 3 coupling (dmax = 3.5, 50% of neuronal projections, 4% average period gradient, K = 1.0, L0 = 0.22). The black bars indicate a dark phase (color code as in Figure 3A). Individual oscillators have an average period of 23.7 ± 1.2 h. Initial conditions were chosen randomly. The first 72 h of transient were discarded, and the time from 72 h to 144 h was retained.
(B,C) Raster plot of Per/Cry mRNA activity in oscillators, organized according to their regions (from bottom up: VLL, left VL region; VLR, right VL region; DML, left DM region; DMR, right DM region; and Int, intersection between left and right DM regions). The concentration of Per/Cry mRNA for each oscillator is represented by colors (blue, low concentration; red, high concentration).
(B) 12:12 LD cycle.
(C) 12:12 LD cycle with a 12 h phase shift at t = 84 h.