Functional α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid receptors in differentiating embryonic neural progenitor cells.

Glutamate-responsive α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptors are considered to play a significant role in neurogenesis. We have studied the functional expression of these receptors in migrating embryonic neural progenitor cells (NPCs). The majority of neurosphere-derived NPCs express AMPA receptors already during the first day of differentiation, based on mRNA quantification, immunocytochemistry, and Ca²+ imaging. The expression of GluR1 mRNA was significantly increased at 5 days of differentiation. The AMPA receptor subunits coexpressed with neuronal markers and were present in all cells at the outer periphery of the migration zone. In migrating NPCs, most of the AMPA receptors were philantotoxin sensitive and Ca²+-permeable, suggesting that in addition to their role in plasticity, the receptors are of importance in NPC differentiation.