GLUTAMATE RECEPTOR-MEDIATED CURRENTS AND TOXICITY IN EMBRYONAL CARCINOMA-CELLS

While primary neuronal cell cultures have been used to investigate exc itotoxicity, development of cell lines exhibiting glutamate receptor-m ediated death is desirable. P19 mouse embryonal carcinoma cells, expos ed to retinoic acid and plated onto a layer of cultured mouse cortical glial cells, differentiated into neuron-like elements immunoreactive for neurofilaments and neuron-specific enolase. Whole-cell recordings revealed inward currents in response to extracellular application of e ither NMDA or kainate. The NMDA-induced currents exhibited a voltage-d ependent blockade by magnesium, required glycine for maximal activatio n, and were blocked by the NMDA antagonist dizocilpine. Kainate-induce d currents were blocked by the AMPA/kainate receptor antagonist CNQX. Exposure to 500 muM NMDA for 24 h destroyed most P19 cells (EC50 appro ximately 70 muM); death was prevented by dizocilpine or D-APV. Exposur e to 500 muM kainate also resulted in widespread death reduced by CNQX . Thus differentiated P19 cells exhibited both excitatory amino acid r esponses and vulnerability to excitotoxicity, characteristic of CNS ne urons. These cells may provide a genetically open system useful for st udying glutamate receptor-mediated phenomena at a molecular level. (C) 1993 John Wiley & Sons, Inc.