NE-7C2 neuroectodermal cells derived from forebrain vesicles of p53-deficient mouse embryos (E9) produce neurons and astrocytes in vitro if induced by all-trans retinoic acid. The reproducible morphological stages of neurogenesis were correlated with the expression of various NMDA receptor subunits. RT-PCR studies revealed that GluRε1 and GluRε4 subunit mRNAs were transcribed by both non-induced and neuronally differentiated cells. GluRε3 subunit mRNAs were not synthesized by NE-7C2 cells and increased numbers of messages from the GluRε2 gene were detected only after neural network formation. The presence of the GluRζ1 protein was detected throughout neural induction, whereas retinoic acid-induced neuron formation elevated the amount of exon 21 (C1)- and exon 22 (C2)-containing GluRζ1 mRNAs and resulted in the appearance of exon 5 (N1)-containing transcripts. NMDA-elicited Ca2+-signals were detected only in cells displaying neuronal morphology, but preceding the appearance of synapsin-1 immunoreactivity. Our findings demonstrated that, in spite of the presence of subunits necessary for channel formation, functional channels were formed by NE-7C2 cells no sooner than the time of neurite maturation. The data show that the cell line provides a suitable model to analyse the mechanisms involved in NMDA receptor gene expression before the appearance of synaptic communication.
- Cell line
- NMDA receptor
- Neuronal progenitors
ASJC Scopus subject areas
- Cellular and Molecular Neuroscience