EXPRESSION AND REGULATION OF KAINATE AND AMPA RECEPTORS IN UNCOMMITTED AND COMMITTED NEURAL PROGENITORS

Here we review experimental evidence of non-NMDA glutamate receptor ex pression in the embryonic central nervous system. AMPA- and kainate-pr eferring glutamate receptor subunit mRNA transcripts are detected in e mbryonic neurons, glia and neural progenitors. Functional assays demon strate that in some cell subpopulations ionotropic glutamate receptors are expressed by;progenitors before synapse formation and terminal di fferentiation, and may be present before lineage determination is spec ified. The activation of these receptors triggers induction of immedia te early gene transcription in progenitor cells. The cloning and trans criptional analysis of upstream regulatory regions of glutamate recept or genes governing their temporal and tissue-specific expression are a lso discussed.