Investigation of morphological and functional changes during neuronal differentiation of PC12 cells by combined hopping probe ion conductance microscopy and patch-clamp technique.

PC12 cells derived from rat pheochromocytoma can differentiate into sympathetic-neuron-like cells in response to nerve growth factor (NGF). These cells have been proved to be a useful cell model to study neuronal differentiation. NGF induces rapid changes in membrane morphology, neurite outgrowth, and electrical excitability. However, the relationship between the 3D morphological changes of NGF-differentiated PC12 cells and their electrophysiological functions remains poorly understood. In this study, we combined a recently developed Hopping Probe Ion Conductance Microscopy (HPICM) with patch-clamp technique to investigate the high-resolution morphological changes and functional ion-channel development during the NGF-induced neuronal differentiation of PC12 cells. NGF enlarged TTX-sensitive sodium currents of PC12 cells, which associated with cell volume, membrane surface area, surface roughness of the membrane, and neurite outgrowth. These results demonstrate that the combination of HPICM and patch-clamp technique can provide detailed information of membrane microstructures and ion-channel functions during the differentiation of PC12 cells, and has the potential to become a powerful tool for neuronal research.