Fig. 8

Captopril treatment reduces the KA-induced synaptic phagocytosis by activated microglia. A Immunostaining of Cd68 (green), synapsin (red) and Iba1 (cyan) in the hippocampal CA1 indicates captopril significantly attenuates the KA-induced synaptic pruning by microglia. Top, scale bar = 5 μm. Bottom, scale bar = 10 μm. B Quantification of Cd68 and synapsin immunofluorescent signals within Iba1⁺ microglia indicates captopril treatment significantly reduces the KA-induced microglia engulfment capacity as measured by lysosomal content within each microglia (CD68 immunoreactivity per cell). C Quantification shows that captopril reduces the KA-induced upregulation of the proportion of microglia with Cd68⁺ (green) signal in the hippocampal CA1. D Representative confocal images of synapsin (red) from pyramidale and radiatum in the hippocampal CA1 are shown. Scale bar = 5 μm. E Quantification of punctuated integrated signal intensity of synapsin indicates captopril significantly attenuates the KA-induced synaptic loss in the pyramidale and radiatum layer of hippocampal CA1. Scale bar = 5 μm. n = 9 images from 3 rats/group, ^###p < 0.001, compared to control; ***p < 0.001, compared to KA, one-way ANOVA followed by Tukey’s post hoc test. Data are presented as mean ± SE