[Correlative research between ERK1/2 cascade and c-fos expression after hippocampal neuron epileptiform discharge]

To investigate the correlation between ERK1/2 cascade and c-fos after hippocampal neuron epileptiform discharge.

Hippocampal neurons were collected from Wistar rats and cultured in magnesium-free extra-cellular fluid to establish hippocampal neuron epileptiform discharge model. Then the hippocampal neurons were divided into 2 groups: inhibitor group, added with 10 micromol/L U0126, inhibitor of ERK 1/2 pathway, and control group without any treatment, got at 0 min). Using double-label immunofluorescence, laser scanning confocal microscopy was performed to detect the disposition of phosphorylated-ERK1/2(p-ERK1/2) and c-fos in the neurons. Western blotting was used to detect the expression of p-ERK1/2 and c-fos 0 min, 30 min, 2 h, 6 h, 12 h, and 24 h following corresponding treatment

Double-label immunofluorescence examination displayed that there was p-ERK1/2 in both the cytoplasm and nucleus, but c-fos in the nucleus only. Western blotting manifested that p-ERK1/2 was observed at each time points in the model group, and the expression pattern of c-fos was the same as p-ERK1/2, which peaked 30 min after treatment. In the inhibitor group, p-ERK1/2 was inhibited completely, and c-fos was decreased obviously. The c-fos expression levels at different time points of the inhibitor group were all significantly lower than those of the model group (all P < 0.01).

After hippocampal neuron epileptiform discharge, ERK1/2 is activated for a long time, and the expression of c-fos is downregulated by blocking the phosphorylation of ERK1/2.