Differential decline in behavioral performance of Drosophila melanogaster with age.

Normal aging is typically accompanied by deficits in behavioral performance, independent of overt pathology. In contrast, some behaviors remain relatively unchanged with age, but the reason(s) they remain intact are not known. Here we compare the relative impact of age on a battery of standard behavioral tests using the model genetic organism Drosophila melanogaster. Consistent with previous reports, learning, locomotion, geotaxis and phototaxis show a dramatic and progressive decline beginning at 1-2 weeks of age. In contrast, using two independent behavioral assays, we observe little or no decline in the flies' ability to escape potentially threatening stimuli. Using the assay with the most rapid decline, geotaxis, we observe a delay in functional aging in a long-lived mutant of the Ecdysone Receptor. We discuss the use of Drosophila genetics to investigate the differential decline in behavioral capacity.