Effects of age and lifetime behavioral patterns on locomotion in Drosophila

Abstract

The effects of behavior on physiology and senescence may be profound in variably active species such as flying insects, which attain among the highest metabolic rates ever measured. Previous studies have shown that limiting flight behavior in insects extends lifespan and slows the age‐related loss of antioxidant capacity and accumulation of oxidative damage in flight muscles. In this study, we manipulated the lifetime flight behavior of Drosophila melanogaster. Specifically, 5‐day old adult flies were separated into three life‐long treatments: (A) those not allowed to fly (no flight), (B) those allowed – but not induced – to fly (voluntary flight), and (C) those mechanically stimulated to perform over 100 flight bouts per day (induced flight). Consistent with the oxidative stress model of aging, Drosophila prevented from flying lived longer than those allowed or stimulated to fly. Flight capacity, measured as the ability to fly in a hypodense gas mixture (21% O2, 39.5% N2, 39.5% He; 0.81 g l−1), decreased with age in all treatment groups, but decreased earliest in flies from the no‐flight treatment. Extended longevity in flies from the no‐flight treatment suggests that oxidative damage accrued more slowly in this treatment group. However, early loss of flight capacity in the no‐flight group indicates that disuse effects were the primary determinant of the age‐dependent muscle impairment in this group. Additional experiments are ongoing to compare age‐dependent oxidative damage, flight muscle ultra‐structure, flight kinematics, immune function, reproduction and metabolic capacity among the treatment groups. Supported by NSF IOS‐0725030.