Fig. 2.  Results of real-time quantitative polymerase chain reaction from whole brain, spinal cord, and dorsal root ganglion (DRG) tissues using K^2Pchannel–specific primers. Each column represents a reaction primed with total RNA isolated from wild-type (Wt), heterozygous (Het), or knockout (KO) mice. The expression levels are represented as relative to an internal calibration standard that was included in all experiments: TRESK primers (A ), TREK-1 primers (B ), TASK-1 primers (C ), and TASK-3 primers (D ).