Depressed hippocampal MEK/ERK phosphorylation correlates with impaired cognitive and synaptic function in...

An experiment was performed to observe changes of mitogen-activated protein kinase ERK (MEK)/extracellular signal-regulated kinase (ERK) signaling pathways in the hippocampus of zinc-deficient (ZD) rats and the correlation with cognitive dysfunction. Forty-four male weanling Wistar rats were randomly assigned to ZD (n = 22) and control (pair-fed, n = 22) groups. After a 4-week treatment, Y-maze was used to test the spatial memory of the rats. The long-term potentiation (LTP) in rat hippocampal dentate gyrus was observed simultaneously. pMEK, pERK1/2, and pCREB protein levels were examined by Western blot assays. The results demonstrated that the latency period in Y-maze was significantly shorter for the ZD rats. LTP amplitude in the ZD group decreased significantly compared with the control group. pMEK, pERK1/2, and pCREB protein expression of hippocampus in the ZD group decreased significantly. The results implicated a possibility that zinc deficiency-induced cognitive and synaptic impairment may be relevant to the MEK/ERK signaling pathway.