Electrophysiological properties of long term cultured human induced neurons

Induced neurons (iNs) are reprogrammed somatic cells that are forced to change their fate without passing through a pluripotent state, shortening the process of neuronal generation compared to the use of human pluripotent stem cells.The scientific interest in these cells is due to their suitable use for disease modelling, drug screening and cell therapy for diseases such as Parkinson Disease (PD). 

An important characteristic of the reprogrammed cells that has to be taken into account to confirm their neuronal identities is their electrophysiological profile. Here, we aim at studying the electrical activity of iNs using the whole cell patch-clamp technique.

We evaluate how the delivery of different transcription factors (TFs) through a lentivirus system induces neuronal maturation. More specifically, we compare the electrophysiological profile of the iNs generated by a combination of Ascl1, Brain2, Myt1L, NeuroD1, Lmx1, Foxa2, Otx2, Nurr1 and REST inhibitionat different time points. The result shows active iNs after  50 days  of culture, with presence of immature, intermediate and mature action potentials induced by steps of current depolarisation. The physiological parameters analysed shows a progressive maturation of the iNs that result to be spontaneously active after 90 days of culture.

This result is an important step in the use of the iNs both for disease modelling and cell transplantation since it indicates that they mature into functional neurons.