Fig. 3: tPA from cortical neurons promotes neuronal survival at the acute phase of excitotoxicity.

A Schematic experimental protocol showing first, the AAV9-Plat-Cre-GFP injection in tPA ^−/− (WT) or flox^+/+ (tPA-cKO^Neu) mice and second, the NMDA injection followed by IHC. B, C Representative images and quantification of the number of tPA non-expressing neurons (red) and tPA-expressing neurons (green) in the lesion area compared to the contralateral area, at 1 and 2 h post NMDA injection (N = 5 (+1 h) and N = 6 (+2 h) mice per time for WT and N = 4 (+1 h) and 4 (+2 h) for tPA-cKO^Neu; Two-way ANOVA, Multiple comparison, Bonferroni post hoc; p < 0.0001 = ****). The percentage of mortality was calculated for both genotypes at 1 and 2 h post excitotoxicity induction (N = 5 (+1 h) and N = 6 (+2 h) mice per time for WT and N = 4 (+1 h) and 4 (+2 h) for tPA-cKO^Neu. Mann–Whitney test; p < 0.01 = ** for NeuN⁺/GFP⁻ cells and Unpaired t-test, p < 0.0001 = **** for NeuN⁺/GFP⁺ cells. Scale bar = 100 µm, ×20. D Representative images and quantification of the tPA non-expressing (red) and tPA-expressing (green) cortical neuronal circularity in the lesion area and the contralateral area of WT or tPA-cKO^Neu mice, 1 and 2 h post excitotoxicity induction (N = 5 (+1 h) and N = 6 (+2 h) mice per time for WT and N = 4 (+1 h) and 4 (+2 h) for tPA-cKO^Neu; Two-way ANOVA, Multiple comparison, Bonferroni post hoc; p < 0.01 = **, p < 0.001 = ***, p < 0.0001 = ****). Scale bar = 100 µm, ×40.