Figure 5

Effects of 17β-estradiol (E2) on LPS-induced microglial activation and DA neuron loss in various brain regions of male mice.

(a) Representative immunostained micrographs show Iba1⁺ cells in the SN, striatum, hippocampus and motor cortex of 3-month-old mice 1 day after an LPS (0.15 mg/kg of body weight, i.p.) or saline (Sal) injection. One hour before the LPS injection, mice were injected with 0, 10 or 100 μg/kg body weight of E2. Quantitative data are shown in the respective right panels. Scale bar: 20 μm. (n = 4). *(p < 0.05), **(p < 0.01), ***(p < 0.001): versus the Sal group; ^#(p < 0.05), ^##(p < 0.01), ^###(p < 0.001): versus the LPS group. (b,c) Changes in Iba1⁺ and TH⁺ cells in the SN of 3-month-old male mice 1 days after an intraperitoneal (i.p.) LPS injection. One hour before the LPS injection, the right SN was injected with E2 and the left with an equal amount of Sal. Representative micrographs are shown in the upper panels. The lower panels are enlargements of the boxes in the upper panels. Quantitative data for a fixed region (0.049 mm²) immediately next to the injection site are shown in the right panels (n = 4). *(p < 0.05): versus the Sal injection side of LPS treatment group. Sal(i.p.): a group of 3-month-old mice given an intraperitoneal injection of saline but no intra-SN injection. The Sal(i.p.) group was a reference group and was not included in the statistical analysis.