Graphic summary of the propagation velocity (θ) as a function of the shunt resistance across the 9 cell junctions (Rgj). TPT was the difference between the times when the AP of cell #1 and cell #10 crossed a Vm of -20 mV. The velocity (θ) was calculated from the TPT assuming a cell length of 150 μm. Assuming the conductance of the gj-channel is 100 pS, the Rgj values of 10, 100, 1,000, 10,000 and 100,000 MΩ correspond to the number of gj-channels of 1,000, 100, 10, 1.0 and 0. For the purpose of graphic presentation, runs were also made for Rgj values of 30, 300, 3,000 and 30,000.