Calcium, sodium and TRP channel expression in human fetal midbrain-derived neural progenitor cells

Voltage-gated sodium and calcium channels as well as transient receptor potential (TRP) channels are expressed during the differentiation of human neural progenitor cells (hNPCs) and are likely to be involved in regulating neurogenesis. However, the molecular composition of these ion channels in proliferating and differentiating hNPCs is largely unknown. Here, we investigated fetal mesencephalic hNPCs in respect to their sodium, calcium, and TRP channel subunit expression and function. Quantitative real-time PCR indicated a significant upregulation of voltage-gated sodium and calcium channel subunits in hNPCs after differentiation for 3 weeks in vitro. In contrast the TRP channel expression did not increase significantly during hNPC maturation. Intracellular Ca2+ measurements showed the marked reduction of KCl-induced Ca2+ transients through inhibition of voltage-gated Ca2+ channels by verapamil and mibefradil in differentiated hNPCs. Application of TRP channel agonists induced intracellular Ca2+ peaks al...