Biological aging of two innate behaviors ofDrosophila melanogaster: escape climbing versus courtship learning and memory

Abstract

ABSTRACTMotor and cognitive aging can severely affect life quality of elderly people and burden health care systems. In search for diagnostic behavioral biomarkers, it has been suggested that walking speed can predict forms of cognitive decline, but in humans, it remains challenging to separate the effects of biological aging and lifestyle. We examined a possible association of motor and cognitive decline in Drosophila, a genetic model organism of healthy aging. Long term courtship memory is present in young flies but absent already during mid life (4-8 weeks). By contrast, courtship learning index and short term memory (STM) are surprisingly robust and remain stable through mid (4-8 weeks) and healthy late life (>8 weeks), until courtship performance collapses suddenly at ∼4.5 days prior to death. By contrast, climbing speed declines gradually during late life (>8 weeks). The collapse of courtship performance and short term memory close to the end of life are not related to the gradual late life decline in climbing speed. Thus, during healthy aging in Drosophila, climbing and courtship motor behaviors decline differentially, unlikely share a common cause, and motor and cognitive performance decline are not closely associated to each other.