ABSTRACT
<p><b>AIM</b>To investigate the neuroprotective effect of learning on glutamate-induced neuronal damage.</p><p><b>METHODS</b>SD rats were intraperitoneally injected with monosodium glutamate (MSG) during the period of 3-9 days after born, and were trained to find their food by light-dark discrimination at 1 month old or 2 months old. At 3 months old, all rats were killed and their brains were taken out and cut into sections and ultrathin sections. The survival neurons in hippocampus were counted under light microscope, and under electric microscope, the ultrastructure, the numbers of synapses and the length of synaptic active zone in fields CA1 of hippocampus were observed.</p><p><b>RESULTS</b>The survival neurons in field CA3 and CA4, the number of synapses and the length of synaptic active zone in field CA1 of hippocampus increased in learning group than non-learning group.</p><p><b>CONCLUSION</b>These finding indicate that discriminative learning can alleviate neuronal injury of hippocampus induced by MSG.</p>