Region-specific phosphorylation of ERK5-MEF2C in the rat frontal cortex and hippocampus after electroconvulsive shock.

ERK5-MEF2C has been implicated in many aspects of neuronal survival and neuroprotection. Neurotrophic effects have been considered as one of the mechanisms in therapeutic electroconvulsive shock (ECS). To investigate whether ECS activates ERK5-MEF2C, we examined the phosphorylation of ERK5, along with its downstream molecule MEF2C, after ECS in the rat frontal cortex and hippocampus. Increased phosphorylation of ERK5 was observed immediately after ECS, but was barely detectable from 2 min after ECS in both the frontal cortex and the hippocampus. The level of MEF2C phosphorylation was decreased immediately after ECS in both regions. It was increased from 2 min and maintained until 10 min after ECS in the frontal cortex, but it returned to the basal level from 2 min after ECS in the hippocampus. Taken together, these results suggest that ECS can regulate the region-specific activity of ERK5-MEF2C pathways in the rat brain.