Fig. 1.

TREK1 is inhibited by extracellular acidification. (A) Effect of pH on TREK1 expressed in Xenopus oocytes. Currents were elicited by voltage-ramps (from −150 to + 50 mV, 1 s in duration). (B) pH dependence of the TREK1 channel activity at 0 mV. (C) pH dependence of TREK1E306A channel activity at 0 mV. Error bars, SEM. At higher levels of expression, TREK1E306 becomes resistant to inhibition. (D) Effect of DEPC preincubation (2 mM) on pH-sensitivity of TREK1. (Inset) the histograms represent the TREK1 current increase induced by a pH shift from 8 to 7.2 at 0 mV, in the absence or in the presence of DEPC. The number of cells tested is indicated in parenthesis.