Continuous low concentration caffeine exposure enhances Drosophila larval locomotion: deep learning analysis

Abstract Caffeine, a xanthine alkaloid present in many foods and beverages, is widely consumed for its stimulating effects on the nervous system. This study employs Drosophila melanogaster larvae as a model organism to investigate the effects of varying caffeine concentrations on locomotor behaviour. Videos of larvae crawling on agar plates were recorded with an industrial camera, and locomotor parameters, including speed, angular velocity, and time to reach the edge, were quantified using the deep learning tool SLEAP to analyse larval trajectories. The results demonstrated that low caffeine concentrations significantly increased larval locomotor speed, reduced angular velocity, and shortened the time to reach the edge, with the most pronounced effects observed at a concentration of 0.5 g/l. Higher caffeine concentrations had a diminished effect on enhancing locomotor activity. The study suggests that continuous exposure to low concentrations of caffeine during development enhances the locomotor activity of Drosophila larvae.