Figure 3. Mathematical model captures the key characteristics of SCN resynchronization dynamics.

Shown is a representative result from simulating the conditions before, during and after TTX administration. A) The synchronization index and B) the simulated per mRNA traces for every 10^th oscillator (core oscillators in red, shell oscillators in blue) show that oscillators lost amplitude and phase coherence during TTX and regained both after the wash restored intercellular communication. C) This representative network consists of a 13×13 grid of core cells (red, connected with a nearest neighbor network and additional long-range connections, gray) and a 13×13 grid of shell cells (blue, connected with a nearest neighbor network, gray). There is one connection to each shell cell from a randomly chosen core cell (dark red) and one (weak) connection to each core cell from a randomly chosen shell cell (light blue). D) The mean period over time and E) mean peak time for each cycle (red for core cells, blue for shell cells) followed trajectories similar to those recorded from SCN slices. In particular, the mean period of core oscillators stabilized before that of the shell and the daily peak of PER expression peaked in the shell cells earlier than those in the core.