< Back to Article

Buffering and total calcium levels determine the presence of oscillatory regimes in cardiac cells

Fig 8

a) Solutions for cytosolic calcium concentration, c_i, as a function of total calcium concentration, . Discontinuous lines represent unstable solutions and continuous lines stable ones. A closer look at the transitions is shown in b). When reducing the total concentration, at , a limit cycle emerges in a Hopf bifurcation, from the upper state, that then becomes unstable. The red lines represent the lower and upper values of the limit cycle. At, , the intermediate unstable fixed point collides with the limit cycle, that disappears in a homoclinic bifurcation. Below , the RyR close state is the only solution. c) Oscillation periods as a function of .

doi: https://doi.org/10.1371/journal.pcbi.1007728.g008