Aluminum alters NMDA receptor 1A and 2A/B expression on neonatal hippocampal neurons in rats

BACKGROUND: High aluminum (Al) content in certain infant formula raises the concern of possible Al toxicity on brain development of neonates during their vulnerable period of growing. Results of in vivo study showed that Al content of brain tissues reached to 74 μM when oral intake up to 1110 μM, 10 times of that in the hi-Al infant formula. METHODS: Utilizing a cultured neuron cells in vitro model, we have assessed Al influence on neuronal specific gene expression alteration by immunoblot and immunohistochemistry and neural proliferation rate changes by MTT assay. RESULTS: Microscopic images showed that the neurite outgrowth of hippocampal neurons increased along with the Al dosages (37, 74 μM Al (AlCl(3))). MTT results also indicated that Al increased neural cell viability. On the other hand, the immunocytochemistry staining suggested that the protein expressions of NMDAR 1A and NMDAR 2A/B decreased with the Al dosages (p < 0.05). CONCLUSION: Treated hippocampal neurons with 37 and 74 μM of Al for 14 days increased neural cell viability, but hampered NMDAR 1A and NMDAR 2A/B expressions. It was suggested that Al exposure might alter the development of hippocampal neurons in neonatal rats.