Fig. 6.
Potassium current from mature neurons expressing Kv2.2 transcripts activate at a more negative membrane potential.A, Potassium currents from neurons that either do not (left) or do (right) express Kv2.2 mRNA. Calibration: 5 msec. B, Neurons that are + or −Kv2.2 have maximal conductance density (Gmax) within the same range; average values are (in pS/μ2): −Kv2.2, 13.2 ± 3.3, n = 7; +Kv2.2, 20.5 ± 3.8, n = 14. C, The normalized conductance (G/Gmax) plotted versus membrane potential for the currents recorded from two neurons shown in Aindicates that neurons that lack Kv2.2 have currents that activate at more depolarized potentials. D, MeanV1/2 for neurons that are negative for Kv2.2 (14.6 ± 0.8 mV, n = 7) is significantly higher than that for neurons positive for Kv2.2 (9.8 ± 1.0 mV, n = 14, p < 0.01). E, Neurons that are + or −Kv2.2 have t1/2 within the same range; average values for t1/2 at 30 mV are (in msec): −Kv2.2, 2.4 ± 0.2, n = 7; +Kv2.2, 2.3 ± 0.2, n = 14.