Figure 4.

Depletion of microglia with Lip-CL leads to severely enhanced loss of neurons in response to excitotoxicity. Graphs represent the percentages of neuronal cell death per hippocampal region (A to C) in response to 0, 10, 15, 25 and 50 μM NMDA in untreated (WT control) and microglia-depleted slice cultures (WT Lip-CL). Microglial depletion alone did not lead to a significant increase in neuronal cell death (A-C; CNTR). However, in the absence of microglia, neuronal cell death in response to NMDA-induced excitotoxicity was severely enhanced in the DG (A) and CA3 (B). Confocal images clearly show the effect of microglial depletion on neuronal degeneration in response to 15 μM NMDA (D-K). Here, in the absence of microglia, neuronal cell death was significantly enhanced in the DG from 12.7% to 66.0% (F,G) and in the CA3 from 41.7% to 94.0% (H, I). In the CA1 (J,K) no significant effect in response to 15 μM NMDA was observed between control and Lip-CL treated slice cultures (97.1% versus 99.8%, respectively). Data are a summary of three individual experiments with at least 6 slice cultures per condition. Bars indicate mean ± SEM. **p < 0.01, ***p < 0.001, ANOVA. Scale bars indicate 300 μM (D,E) and 75 μM (F-K).