Roles of GJs in synchronizing DC- induced spikes in simulated networks. A1) Current (200 pA) injection in one of the GJ coupled cells (black trace) induced direct (black) and coupled (gray) responses in both cells. Cells in A1, A2 & A3 have a EPJP strength of 0 (A1), 0.2(A2) & 0.6 (A2), respectively. A4) Cross-correlation coefficient plotted against strength of EPJP conductance in the simulation (n = 10 trials). Solid line: data fitted with a Bolztmann equation. B) Recordings were made from a GJ coupled FS pair (EPJP conductance of 0.2 nS) in a brain slice.