Comparison of CV for different tissue models, intermembrane separation, and GJ coupling strength. (A) Strong GJ coupling: CV in the single-cleft and network models is slower compared with the monodomain model. In the cleft models, CV slightly increased for increased intermembrane separation (in the single-cleft model) and interplicate distance d_Ip (in the cleft network model). (B) Intermediate GJ coupling: CV is slightly reduced in the cleft models, with minimal dependence on intermembrane separation. (C) Weak GJ coupling: CV is reduced in the single-cleft model but increased in the cleft network model, with different dependence on intermembrane separation. (D) Left: For all d_Ip values, CV decreases as gap junctional conductance g_gap decreases. CV is more sensitive to d_Ip for either high or low g_gap, and CV is less sensitive to g_gap for low d_Ip. Right: Cleft network model CV, normalized to the monodomain CV, is typically >1 for low g_gap and <1 for high g_gap. This ratio is highly sensitive to d_Ip for low g_gap. Dotted gray lines corresponding to g_gap values in A–C. Note the logarithmic scale for the x axis. Parameters: g_gap (nS): A, 388; B, 116; C, 38.8; cleft network plicate distance, d_P = 30 nm; single cleft intermembrane separation, d = d_Ip.