Figure 3.

Co-upregulation of APP and Nebula enhances age-dependent memory impairments and exacerbates mitochondrial dysfunctions. A, Quantification of STM during aging. n = 18 trials, *p < 0.05 compared with age-matched control flies and flies overexpressing APP or Nebula at 3 and 10 d. At 30 and 45 d, *p < 0.05 compared with age-matched control flies and APP, APP and Nebula, or Nebula overexpressing flies. B, There is no change in the effectiveness of the C739–GAL4 driver during aging. Western blot shows similar levels of APP in young flies between 2 and 4 or 42 and 45 d old expressing the APP transgene driven by the C739–GAL4 driver. APP levels were normalized to control flies and tubulin. n = 3 independent experiments. C, Images of dissected brains from 42- to 45-d-old flies stained with Fasciclin II antibody. The α and β lobes analyzed are highlighted. There is no change in the gross mushroom body structure or size across genotypes in aged flies. n > 6 brains per genotype. D, Aging causes an increase in calcineurin activity. Nebula still effectively inhibits calcineurin in 42- to 45-d-old flies (aged flies). n = 11 independent experiments. E, Nebula upregulation exacerbates decline in the overall ATP content in aged flies. All values were normalized to young flies done in parallel experiments. n = 8 independent experiments for young and old flies. F, Pseudocolored images and quantification of dihydroethidium staining in the brains of young and aged Drosophila. n = 5 independent experiments per genotype per condition. Scale bars: C, F, 50 μm. All values represent mean ± SEM. For D and E, *p < 0.05 compared with young controls or as indicated.