Romanian Reports in Physics, Vol. 67, No. 2, P. 439–451, 2015 ELECTROPHYSIOLOGY AND PHARMACOLOGY STUDY OF A HUMAN NEUROBLASTOMA CELL LINE * F. HALITZCHI, L. JIANU, B. AMUZESCU University of Bucharest, Faculty of Biology, Dept. Biophysics & Physiology, Splaiul Independentei 91–95, Bucharest 005095 Romania, E-mail: fhalitzchi@yahoo.com Email: ianculelioara.inl@idilis.ro, E-mail: bogdan@biologie.kappa.ro Received August 30, 2013 Abstract. Via patch-clamp experiments on undifferentiated human neuroblastoma cells we identified tetrodotoxin-sensitive Na + channels, delayed rectifier K + channels, while Ca 2+ channels, transient outward K + channels and hyperpolarization-activated channels were absent. Key words: SH-SY5Y neuroblastoma cell line, whole-cell patch-clamp, delayed rectifier K + current, voltage-dependent Na + current, steady-state inactivation, recovery from inactivation. 1. INTRODUCTION Neuroblastoma is a tumour formed by neuronal precursors of the sympathetic nervous system (SNS), derived from the neural crests, present at birth or detected during the first years of childhood, usually before the age of 10. The primary tumour can be located in any SNS structure, most frequently in one of the adrenal glands, but also in the sympathetic nerve tissue of the neck, chest, abdomen or pelvis. During embryonic development, a common sympathoadrenal precursor differentiates into three distinct cell lineages: chromaffin cells, that in turn generate the adrenal gland and paraganglia, and may degenerate into pheochromocytoma and sympathetic paraganglioma, respectively, small intensely fluorescent or SIF cells, and sympathetic neuroblasts. The SIF cells further condense into sympathetic ganglia, while sympathetic neuroblasts generate sympathetic neurons with bodies within sympathetic ganglia and the developing adrenal gland [1]. The latter two lineages can both generate neuroblastomas, lobular with neuroendocrine differentiation capacity and adrenal/extraadrenal, respectively. Neuroblastomas * Paper presented at the Annual Scientific Session of Faculty of Physics, University of Bucharest, June 21, 2013, Bucharest-Magurele, Romania.