Figure 10.

Mg²⁺-dependent modulation of G_j in pairs of MesV neurons. A, IR-DIC image of a pair of electrically coupled MesV neurons during dual whole-cell patch clamp. B, Simultaneous current-clamp recordings from a pair of electrically coupled MesV neurons; arrows indicate the direction of the spread of electrotonic potential. Voltage traces were recorded from cell-1 and cell-2 (V₁ and V₂, respectively) during 300 ms hyperpolarizing current steps of −300 pA injected either in cell-1 or in cell-2 (I₁ and I₂, respectively). C, Time course of changes in mean G_j (normalized to initial values) at [Mg²⁺]_p = 0.01 (gray) and 5 mm (black). Each point represents an average from five independent experiments. D, Mean percentage changes of G_j from initial values after 12 min of patch openings with [Mg²⁺]_p = 0.01 (gray) and 5 mm (black). Numbers of cell pairs are indicated within columns; *p < 0.05.