The functional development of an immortalised hNPC line, ReNcell VM, was investigated in standard cell cultures and after transplantation on to hippocampal organotypical brain slice cultures. Upon differentiation the hNPCs could develop into cells with neuronal phenotype and express functional Na+ and K+ channels. Stimulation of cells in cell culture with veratridine, a Na+ channel agonist, improved their survival, indicating the presence of an activity-dependent survival mechanism. hNPCs transplanted onto slice cultures were found to rapidly receive synaptic input, shown by recordings of post synaptic currents. Ca imaging studies revealed that the hNPCs exhibited spontaneous Ca transients during proliferation and differentiation. Pharmacological characterisation suggesting these were underlain by TRP channels. Notably, TRPV1 and/or TRPV3 channels were identified during proliferation, but were downregulated during differentiation. The level of Ca signalling could be regulated by adjusting the extracellular K concentration. Culturing cells in lowered K slowed proliferation and increased the proportion of cells in G1 phase without inducing cell cycle arrest or reducing viability. The findings of this study provide insights into the functional properties of hNPCs, and identify a new method by which their development might be controlled in culture.