Figure 6.

K_ir4.1 inhibition does not reveal the functional contribution of TWIK-1/TREK-1 in double gene knockout mice. (A) Representative V_M response to K_ir4.1 inhibitor, 100 μM BaCl₂, from a WT and a TWIK-1^−/−/TREK-1^−/− astrocyte as indicated in situ. (B) Summary of 100 μM BaCl₂-induced V_M depolarization, where the V_M depolarization was comparable between WT and TWIK-1^−/−/TREK-1^−/− astrocytes. (C) Representative whole-cell current recorded first in control, then 5 min in 100 μM BaCl₂, and washout. I–V relationships were shown in (D). (D) I–V plots derived from recordings in (C). The Ba²⁺-sensitive currents, in I-V plots were obtained from sweep subtraction. The Ba²⁺- sensitive currents were shown in expanded y-axis in the inset that showed a moderate inward rectification in both WT, RI = 0.91, and double gene knockout mice, RI = 0.90, respectively. (E) Summary of RI values from WT and TWIK-1^−/−/TREK-1^−/− astrocytes obtained from recordings in the presence of 100 μM BaCl₂ for K_ir4.1 inhibition; the RI values were comparable between the two groups.