Development of resting membrane potentials in differentiating murine neuroblastoma cells (N1E-115) evaluated by flow cytometry

With the aid of a voltage-sensitive oxonol dye, flow cytometry was used to measure relative changes in resting membrane potential (Vm) and forward angle light scatter (FALS) profiles of a differentiating/differentiated murine neuroblastoma cell line (N1E-115). Electrophysiological differentiation was characterized by Vm establishment. The (Vm)-time profile was found to be seed cell concentration-dependent for cell densities of less than 2 × 104 cells/cm2. At higher initial cell densities, under differentiating culture conditions, Vm development commenced on day 2 and reached a steady-state on day 12. The relative distribution of differentiated cells between low and high FALS has been proposed as a potential culture electrophysiological differentiation state index. These experiments offer a general methodology to characterize cultured excitable cells of nervous system origin, with respect to electrophysiological differentiation. This information is valuable in studies employing neuroblastoma cells as in vitro screening models for safety/hazard evaluation and/or risk assessment of therapeutical and industrial chemicals under development.