Figure 4. Activation of mitoK_ATP channels in single astrocyte increased the electrical coupling of directly coupled astrocytes in slices.

Internal solution containing test drugs was used to diminish the pharmacological effects induced by opening/blocking neuronal K_ATP channels in slice. (A) Representative electrical coupling trace of a recorded astrocyte pair after addition of DIZ in cell1 (A1), and after addition of DIZ in cell1 and 5-HD in cell2 for 5 min (A2). (B) Bar graph shows that compared to that observed in DIZ-treated slices, we did not find any differences in coupling ratios with the internal solution containing DIZ at 5 min. Interestingly, the level of coupling ratios from the S_cell with DIZ-contained internal solution (S_cell-DIZ) to the R_cell with normal internal solution (R_cell-) was higher than that from the S_cell with normal internal solution (S_cell-) to the R_cell with DIZ-containing internal solution (R_cell-DIZ). Moreover, the level of coupling ratios from the S_cell- to the R_cell with 5-HD-containing internal solution (R_cell-5-HD) was higher than that from the S_cell with 5-HD-containing internal solution (S_cell-_5-HD) to the R_cell-, even though the differences in the ratios were not significant. When S_cell-DIZ was combined with R_cell-5-HD in our experiments, this elevation in coupling ratios became significant, as the level increased by 58% and 68% than that from S_cell-DIZ to R_cell- and S_cell-DIZ to R_cell-DIZ respectively. These results were determined from paired astrocyte recordings at interastrocytic distances of 20 – 40 µm. Mean ± SEM; * P<0.05. ^# P<0.05 compared to the control. DIZ, Diazoxide; 5-HD, 5-hydroxydecanoate; R_cell, recipient cell; S_cell, stimulated cell.