Figure 1.
TASK-3 KO mice exhibit a reduced potassium leak conductance. In situ hybridization data from adult wild-type (A, C) and TASK-3 KO (B, D) mouse brains comparing the distribution of TASK-3 (A, B) and TASK-1 mRNA (C, D). TASK-3 mRNA is absent from TASK-3 KO brains with no change in the expression of TASK-1 mRNA. Shown are neocortex (Cx), dentate gyrus (DG), caudate putamen (CPu), medial habenule (Hb), periglomerular (Pgl) and granule neurons (Obgr) of the olfactory bulb, reticular nucleus of the thalamus (RT), and CGNs. Scale bar, 2 mm. E, Comparison of mRNA levels between wild-type and TASK-3 KO cerebellum (real-time PCR) for seven K2P subunits and the GABAA receptor α6 subunit. The only significant difference between the genotypes was the absence of TASK-3 mRNA (asterisk). A similar pattern was observed for real-time PCR data in the forebrain (data not shown). Error bars indicate SEM. F, A typical voltage-clamp recording illustrating the standing outward potassium current recorded at −20 mV in a wild-type adult CGN. The command voltage has been maintained at −20 mV for at least 1 min before the amplitude of the non-inactivating component of this leak conductance was measured. The voltage was then ramped down to −110 mV in 800 ms to construct the current–voltage plots shown. G, These graphs compare the average current–voltage relationships for 34 wild-type CGNs (black trace) and 16 TASK-3 KO CGNs (gray trace).