Fig. 1.

Characteristics of neural stem cells (NSCs) and neurons. A: NSCs were cultured in 21% O₂-5% CO₂. Cells were costained by using antibodies directed against mouse stem cell marker nestin and neuronal markers MAP2 (a–d) or against nestin and the neuronal marker NeuN (e–h). All cells expressed nestin (b, f), but there was no detectable MAP2 or NeuN (a, e). Phase contrast (Ph. Contr.) microscopy revealed a pyramidal shape of the cells (i), and only very few dead cells were observed or were seen with propidium iodide (PI) labeling (j). Magnification: ×100; insets, ×400. Western blot analysis confirmed the absence of MAP2 and NeuN from NSCs (k). B: primary neurons were cultured from embryonic day 17 mouse cortex in normoxia for 8 days. Immunocytochemistry was performed for nestin, MAP2, and NeuN. There was a complete absence of nestin (b). MAP2 (a, e), and NeuN (f) were detected in all cells. Phase contrast microscopy revealed typical neuronal shape with processes and synapses (i). Magnification: ×100; insets, ×400. Western blot analysis confirmed the presence of MAP2 and NeuN and the absence of nestin from primary neurons.