Abstract
A clonal stem cell line, RT4-AC, of the rat peripheral neurotumor RT4 differentiates in culture into morphologically distinct cell types RT4-B, RT4-D, and RT4-E (cell type conversion). The multipotential stem cell type RT4-AC and cell type RT4-D produce a glial marker, S100 protein, but RT4-B and RT4-E do not. The stem cells also show a small but significant response to veratridine on voltage-dependent Na+ influx. Cell types RT4-B and RT4-E show a clear response of voltage-dependent Na+ influx to veratridine, typical of neuronal cells, whereas cell type RT4-D is completely negative. These results indicate that (i) the stem cell type RT4-AC shows both neuronal and glial properties, (ii) cell types RT4-B and RT4-E have a neuronal property, and (iii) cell type RT4-D has a glial property. Therefore, cell type conversion of stem cell RT4-AC to RT4-B and RT4-E cells seems to result in differentiation towards neuronal cell types, and cell type conversion of RT4-AC to RT4-D results in differentiation towards a glial type in culture.