Human central neurocytoma cells were cultured and characterized immunophenotypically and electrophysiologically to clarify their developmental potential. We conducted systematic in vitro studies utilizing fresh tissues from three patients. Initially small homogeneous cell clusters settled down onto the bottom of the culture flasks, and, after 2 weeks from plating, mature neuron-like cells developed from these clusters and expressed neurofilament proteins (NF: specific neuronal markers). On the other hand, approximately 80% of small round cell clusters and flat glial-like cells from which these clusters developed were positively stained for glial fibrillary acidic protein (GFAP: a specific glial marker). Furthermore these neuronal and glial cells showed distinct morphology, and dual-label, indirect immunohistochemistry for GFAP and NF-200 kD disclosed that the two antigens were not found co-localized in the same cells. In single-cell clonal analysis, neuronal, glial, and mixed neuronal and glial clones were generated. Electrophysiologically, the cells of neuronal morphology possessed sodium channels, and also L-type calcium channels in whole-cell voltage clamp. The sodium channels were of a characteristic neuronal phenotype which appears in neurons. These findings suggest that small round human central neurocytoma cells exhibit both neuronal and glial differentiations and have the properties reminiscent of precursor cells derived from subventricular matrix; thus, these cultured cells may be a potential source for investigations of human CNS neuronal and glial development and differentiation.