Serum-free induced neuronal apoptosis-like cell death is independent of caspase activity

Cultured cortical neurons survived in a density-dependent manner under serum-free conditions. Low-density cultured cells died in an aurintricarboxylic acid (ATA)-sensitive manner, which was accompanied with marked chromatin condensation and nuclear fragmentation. These features, characteristic for apoptosis, were not attenuated by DEVD-CHO, a caspase-3-specific inhibitor, or zVAD-FMK, a broad range caspase inhibitor, while zVAD-FMK showed a marked inhibition of camptothecin-induced cell death. Therefore, cortical neurons died in an apoptosis-like and a caspase-independent manner under serum-free conditions.