[Comparative analysis of cytotoxic action of quinolinic acid and N-methyl-D-aspartate on cultured hippocampal neurons].

A comparative morphological study of neurocytotoxic effect of quinolinic acid (QUIN) and N-methyl-D-aspartate (NMDA) in dissociated hippocampal cell culture of mouse embryos of 17-19 days' gestational age was performed. The addition of NMDA (0.2 mM) to the younger, 10 days in vitro (DIV) cultures containing immature synaptic contacts, as well as to cultures in which the mature synapses were observed (3 weeks in vitro) led to total nerve cell destruction for 24 hours. On the other hand, QUIN (0.5 mM) didn't provoke neuronal degeneration on the 10 th DIV, whereas the 21-DIV cultures exposed to QUIN showed the pronounced neurocytotoxic damage, with characteristic destruction of postsynaptic dendrites and preservation of presynaptic axon terminals. The action of toxins was blocked by specific NMDA receptor antagonist D,L-2-amino-5-phosphonovalerate. Thus, our results supplement the literature communications about the existence of NMDA-receptor subtype which mediates the neurocytotoxic effect of QUIN, and permit to suppose that these receptors appear to be expressed as far as maturation of synaptic connections occurs and functioned in the mature synaptic complex.