[Effect of electroacupuncture on complement C1q and microglia phagocytosis in hippocampus of SAMP8 mice].

OBJECTIVE: To observe the effect of electroacupuncture (EA) on the expression of Iba-1, complement C1q and CD68 in hippocampus of SAMP8 mice, so as to explore its mechanisms underlying improvement of Alzheimer's disease (AD). METHODS: Twenty-four male SAMP8 mice were randomly and equally divided into model and EA groups, and 12 SAMR1 mice were used as the control group. EA (2 Hz, 1.5-2.0 mA) was applied to "Baihui" (GV20), "Dazhui"(GV14) and "Shen-shu"(BL23) for 20 min once daily in the EA group, each course of treatment was 8 days, with an interval of 2 days between two courses, and the mice were treated for 3 courses. Morris water maze test was performed to assess the learning-memory ability of mice. The positive expression levels of Iba-1 and CD68 proteins in the hippocampus CA1 region were detected by immunohistochemistry. The mRNA and protein expression levels of Iba-1,C1q and CD68 in the hippocampus were detected by real-time PCR and Western blot, separately. RESULTS: Compared with the control group, the average escape latency of Morris water maze test was prolonged in the model group (P<0.01), duration of swimming in the original platform quadrant and the number of original platform crossing were significantly shorter and decreased respectively (P<0.01). Compared with the model group, the average escape latency in the EA group was shortened (P<0.05, P<0.01), the duration of swimming in the original platform quadrant and the number of original platform crossing were significantly prolonged and increased (P<0.01). The immunoactivity of Iba-1 and CD68 in hippocampal CA1 region, and mRNA and protein expression levels of hippocampal Iba-1,C1q and CD68 were significantly up-regulated in the model group in contrast to the control group (P<0.01, P<0.05), and obviously down-regulated except the mRNA expression level of hippocampal Iba-1 in the EA group relevant to the model group (P<0.01, P<0.05). CONCLUSION: EA can improve the learning and memory ability of SAMP8 mice, which may be associated with its effect in inhibiting of complement C1q-dependent microglial phagocytosis in the hippocampus.

[Effects of alpine meadow degradation on soil carbon, nitrogen, and carbon stable istope in Zoige Plateau.] / è‹¥å°”ç›–è‰ç”¸é€€åŒ–å¯¹åœŸå£¤ç¢³ã€æ°®å’Œç¢³ç¨³å®šåŒä½ç´ çš„å½±å“.

To investigate the differences of soil carbon, nitrogen, and carbon stable isotopes in Zoige wetland, we analyzed the abundance of carbon stable isotopes and the contents of carbon and nitrogen in soils of three kinds of retrogressive successional grasslands (swampy meadow, steppe meadow, and degraded meadow). The results showed that the δ13C values in the meadow soil of Zoige alpine wetland ranged from -26.21‰ to -24.72‰. The abundance of δ13C increased with the depth of soil. There was a significantly negative relationship between δ13C values and logarithm of soil organic carbon content across the soil profile. The δ13C values in the surface soil (0-10 cm) followed the order of grassland meadow>degraded meadow>swampy meadow, and the ß values followed the order of grassland meadow>swampy meadow>degraded meadow. Soil organic carbon content was 105.32, 42.11 and 31.12 g·kg-1, while nitrogen content was 8.74, 3.41 and 2.81 g·kg-1, and C/N was 11.26, 11.23 and 10.89, in the swampy meadow, grassland meadow and degraded meadow, respectively. The soil C/N was lower in degraded meadow than that in swampy meadow and grassland meadow. The total organic carbon and nitrogen content decreased obviously with increasing soil depth. The variations of soil δ13C among meadows with different degradation stages were mainly restricted to the 0-10 cm soil layer. The ß values and C/N were the lowest in degraded meadow among three stages, suggesting that the mineralization rate of degraded meadow soil organic matter was relatively fast.