Fig. 3.
Expression of Kv1.1 precedes that of Kv2.2 during development of IKv. Neurons were examined for either Kv1.1 or Kv2.2 transcripts at times in culture when potassium current (top) is still small (6–7 and 8–10 hr) and when the current is fully mature (18–22 hr). Frequency of transcript expression of both Kv1.1 and Kv2.2 is developmentally regulated. Kv1.1 transcripts are detected in 12 ± 6% of cells by the onset of morphological differentiation, whereas Kv2.2 transcripts are below the level of detection as late as 8–10 hr in culture. For these three time points, the numbers of cells examined (number of experiments) were 29 (5), 29 (4), and 51 (10) for Kv1.1, and 12 (2), 12 (3), and 32 (6) for Kv2.2. Expression of Kv1.1 is significantly different between 6–7 hr and later times (p < 0.05).