Figure 5.

sc-tPA specifically promotes NMDAR-dependent signaling. (a–c) Neuronal death was assessed by measuring LDH release in the bathing media harvested 24 h after a 1-h exposure of primary cultured cortical neurons (14 DIV) to 50 μM NMDA alone or supplemented with increasing concentrations of either (a) sc-tPA or (b) tc-tPA (12 nM/60 nM/120 nM/300 nM) (n=12, three independent experiments) or (c) in the presence of a molar concentration of 60 nM tPA, using differential ratios of sc-tPA and tc-tPA from 40 to 100% (n=16, four independent experiments). Data are presented as the mean value±S.D. of neuronal death in percent relative to control (**P<0.02; *P<0.05; ns: not significant)