Fig. 8.

Effect of anti-BDNF and anti-IGF-1 blocking antibodies on the protective effects of NMDA, BDNF, or IGF-1. Cerebellar granule neurons were prepared and grown in medium containing 5 mm KCl, as described in Materials and Methods.A, On day 4 in vitro, the anti-BDNF blocking antibody (1 μg/ml) was added 3 hr before the addition of NMDA (100 μm) or BDNF (100 ng/ml). The number of apoptotic cells was determined 24 hr after NMDA or BDNF addition using the ApopTag kit, as described in Materials and Methods. The number of apoptotic cells is reported as the percent of total cells. Values represent the mean ± SEM of 6–12 observations in three separate experiments. Kruskal–Wallis ANOVA revealed a significant effect of treatment (H = 57.8; df = 5;p < 0.001); *p < 0.001 compared with the 5 mm KCl group in the absence of antibody, and **p < 0.001 compared with the appropriate treatment in the absence of antibody (post hoc comparisons). B, The protective effect of NMDA (100 μm) and IGF-1 (50 ng/ml) was assessed in the absence and presence of an anti-IGF-1 blocking antibody (20 μg/ml), exactly as described above for the anti-BDNF antibody. Values represent the mean ± SEM of 6–12 observations in three separate experiments. Kruskal–Wallis ANOVA revealed a significant effect of treatment (H = 55.4; df = 5;p < 0.001); *p < 0.001 compared with the 5 mm KCl group in the absence of antibody, and **p < 0.001 compared with the IGF-1 group in the absence of antibody (post hoccomparisons).