TNF does not interfere with neural stem cell differentiation. (A) Immunostaining of neuronally differentiated neurosphere-derived NSCs. Cells were cultured on poly-D-lysin/laminin-coated dishes in the absence of EGF and bFGF, as described in Materials and Methods. β-III-tubulin expression as a marker for immature neurons was up-regulated in the cells 3 days after adhesion to the coated substrate. (B) TNF treatment does not significantly change the percentage of β-III-tubulin positive cells (P > 0.05) Bars depict 5 μm. (C) Dissociated NSCs were cultured for four days in the absence of cytokines in medium containing 10% FCS followed by fixation and staining for GFAP. Note that TNF treatment had no effect on the capacity for differentiation into the glial lineage. Bar, 100 μm.