Changes of GJC in the pair of neurons exhibiting bursting activity. (A–D) Demonstration of changes in V_m, V_j, and g_j over time for GJs formed of hypothetical Cx45 in response to an I_ext step of 15 pA. (B) Burst of APs evoked in cell 1 (red) and then transferred to cell 2 (blue). Inset shows that the delay between APs was ∼2 ms. (C) Transjunctional voltage was defined as V_j = V_{m,cell 1} − V_{m,cell 2}; inset shows bipolar V_j spikes arising because of a phase difference between APs. (D) Decay of g_j during the I_ext step. (E) Decay of g_j of GJs formed of connexin exhibiting gating properties resembling those of Cx36. (F) Delay of AP transfer from cell 1 to cell 2 increased by ∼38% in cells expressing Cx45 and at a much smaller level for cells expressing Cx36. (G) Predicted reduction in g_j during I_ext steps of 15 pA in the cell pair expressing various Cx isoforms. All simulations were performed using an MC16SM.