Mitochondrial complex I inhibition produces selective damage to hippocampal subfield CA1 in organotypic slice cultures.

The effects of mitochondrial respiratory chain inhibitors and the excitotoxin N-methyl-D-aspartate (NMDA) on cell death in hippocampal subfields CA1 and CA3 were examined in hippocampal organotypic slice cultures. Slice cultures, 2-3 week old, were exposed for 1 h to either the Complex I inhibitors, rotenone or 1-methyl-4-phenylpyridium (MPP+), the Complex II inhibitor 3-nitropropionic acid (3-NP), or the excitotoxin NMDA. Cell death was examined 24 and 48 h following treatment, by measuring propidium iodide (PI) fluorescence. Treatment with 1 micro M Rotenone caused greater cell death in hippocampal subfield CA1 than CA3. Exposure of hippocampal slice cultures to 10 micro M rotenone, to MPP+ or to NMDA resulted in damage to both CA1 and CA3 subfields. 3-NP produced little damage in either subfield. The data suggest that mitochondrial Complex I inhibition can produce selective cell damage in hippocampus and in this regard is similar to that observed following hypoxia/ischemia.