TNF rarely triggers apoptosis in NSCs. (A) NSCs were collected using cytospin centrifugation. Apoptosis was detected using TUNEL with FITC-conjugated dUTP. Control cultures were treated with DNAse I to generate nicked DNA. Terminal deoxynucleotidyl transferase was omitted for negative controls. TNF treatment only slightly increased the number of FITC-positive cells. (B) Quantification of apoptotic cells (***P < 0.01).