Macroscopic conductance and gap junction plaque morphology in cells co-expressing Cx40-WT and Cx40-Q58L. A: Junctional conductance of cells transfected with plasmid pEGFPN1-Cx40-WT (1 μg; data labeled “WT”), pEGFPN1-Cx40-Q58L (1 μg; column “Q58L”), or co-transfected with WT and Q58L (WT/Q58L: pEGFPN1-Cx40-WT 0.5μg+pEGFPN1-Cx40-Q58L 0.5 μg). Asterisks: p<0.001 compared with WT. B: Phase contrast/fluorescence overlay image of N2A cells transfected with WT/Q58L constructs. Arrow “a” points to gap junction plaque; arrow “b” shows example of cells transfected but void of gap junction plaque. Calibration bar: 20 μm. C: Efficacy of gap junction plaque formation was measured as ratio between number of gap junction plaque-positive cells and number of fluorescent-positive cells (WT: n=940, WT/Q58L: n=855, Q58L: n=1,318). Asterisks: p<0.001 compared with WT. D: Representative images of phase contrast (left), EGFP fluorescence (middle), and junctional conductance (right) from N2A cells co-transfected with pEGFPN1-Cx40-WT (0.25 μg) and pEGFPN1-Cx40-Q58L (0.25 μg). Three different examples (a-c) are shown to illustrate relation between plaque morphology and recorded junctional conductance.