Fig. 3

Range of calcium waves. Simulations on a cylindrical model dendrite (radius 0.2 μm) containing a cylindrical ER (radius 40 nm, 50 nm, 60 nm, 70 nm, 80 nm) reveal that there is a threshold RyR density (at the singularities of the plotted curves) above which calcium waves are stable. Decreasing the RyR density below the threshold induces abortive waves, whose travel distances rapidly decline with RyR density reduction. Larger ER domains lead to a lowering of the stabilizing RyR density threshold (singularity moves to the left), indicating that the ability to sustain a calcium wave depends on the rate at which calcium can be released from the ER