Effect of Redepolarization on c-Jun in Cerebellar Granule Neurons

To explore the effect of redepolarization(25 mmol/L K +) on c Jun protein in primarily cultured rat cerebellar granule neurons and its underlying mechanism. Western blotting was used to detect the phosphorylated and non phosphorylated c Jun. Reverse transcription polymerase chain reaction(RT PCR) was used to detect the expression of c jun. Coimmunoprecipitation was used to detect the activity of c Jun N terminal kinase(JNK). Fluorescein diacetate(FDA) was used to assess the viability of neurons. Dramatic elevation of c jun mRNA, total and phosphorylated c Jun were observed after repolarization(5 mmol/L K +) of cerebellar granule neurons, followed by significant decrease of neuronal viability. Redepolarization 2 hours after repolarization rescued neurons from death with rapid inhibition of expression, synthesis, and phosphorylation of c Jun. Activity of JNK through the switching was unchanged. [Conclusion] Rescue of cerebellar granule neurons from death by redepolarization may be mediated by inhibition of c Jun, which is independent of JNK activity.