Cognitive deficits induced by melamine in rats

Many studies reported that infants and animals were affected by food containing melamine, and the renal pathology was the main manifestation in intoxicated case. Our previous studies showed that melamine could impair hippocampal function and inhibited differentiated PC12 cell proliferation in vitro. The present study aimed to examine the effect on hippocampus and the possible mechanism induced by melamine in vivo. To address the hypothesis that melamine would impair the hippocampal function in vivo and then induce cognitive deficits, male Wistar rats were used to establish an animal model and melamine administered at a dose of 300 mg kg/day for 4 weeks. Morris water maze (MWM) test was employed to evaluate the learning and memory. The long term potentiation (LTP) from Schaffer collaterals to CA1 region in the hippocampus was recorded. The result of MWM test showed that there were significant deficits of learning and memory induced by melamine. LTP test presented that field excitatory postsynaptic potentials (fEPSPs) slopes were significantly lower in melamine group compared to that in control group. In conclusion, melamine had a toxic influence on hippocampus, which induced the learning and memory deficits. It suggested that the potential mechanism was associated with impairments of synaptic plasticity.