HIPPOCAMPAL MOSSY FIBER CHANGES IN MICE TRANSGENIC FOR THE HUMAN COPPER-ZINC SUPEROXIDE-DISMUTASE GENE

The copper-zinc superoxide dismutase (SOD-1) gene, located on chromoso me 21 and triplicated in Down's syndrome (DS), is suspected to be invo lved in the neuropathology observed in Alzheimer's disease (AD), DS an d physiological aging. In order to explore the effect of an overproduc tion of SOD-1 in the mouse hippocampus, we investigated the Timm-stain ed mossy fiber (MF) innervation in the hippocampus of transgenic mice for the human SOD-1 gene (hSOD-1 mice). The results showed a decrease of the MF projection area in the hSOD-1 mice overexpressing the SOD-1 protein. These findings suggest that free radicals could play a role i n this particular synaptic loss.