FIGURE 4.
Neuritin-induced IA densities and the increased expression of Kv4.2 α-subunit were dependent the ERK signaling pathway. A, Western blot showing the levels of phosphorylated ERK1 (pERK1) and phosphorylated ERK2 (pERK2) in CGNs incubated with 150 ng/ml neuritin for 15 min to 24 h. Chemiluminescent signals were detected by exposure to x-ray film. B, effect of MEK inhibitor, U0126, on neuritin-induced up-regulation of IA densities. *, p < 0.05 compared with vehicle control (medium without neuritin) by unpaired t test. Error bars, S.E. C and D, effect of U0126 on neuritin-induced up-regulation of Kv4.2 protein level. E, effect of U0126 on neuritin-induced up-regulation of Kv4.2 mRNA expression measured by quantitative RT-PCR experiments. Data obtained from five independent experiments are shown as means ± S.E. *, p < 0.05 compared with corresponding control by unpaired t test.