Blockade of N-methyl-D-aspartate receptors by ketamine produces loss of postnatal day 3 monkey frontal cortical neurons in culture

Ketamine, an N-methyl-D-aspartate (NMDA) receptor antagonist, is used as a general pediatric anesthetic. Recent data suggest that anesthetic drugs may cause neurodegeneration during development. The purpose of this study was to determine the robustness of ketamine-induced developmental neurotoxicity using rhesus monkey frontal cortical cultures and also to determine if dysregulation of NMDA receptor subunits promotes ketamine-induced cell death. Frontal cortical cells collected from the neonatal monkey were incubated for 24 h with 1, 10, or 20 mu M ketamine alone or with ketamine plus either NR1 antisense oligonucleotides or the nuclear factor kB translocation inhibitor, SN-50. Ketamine caused a marked reduction in the neuronal marker polysialic acid neural cell adhesion molecule and mitochondrial metabolism, as well as an increase in DNA fragmentation and release of lactate dehydrogenase. Ketamine-induced effects were blocked by NR1 antisenses and SN-50. These data suggest that NR1 antisenses and SN-50 offer neuroprotection from the enhanced degeneration induced by ketamine in vitro.