The effect of L-alanine on sleep through taste properties in Drosophila melanogaster

Sleep and nutrition are important for the survival of organisms. This study focuses on the effects of amino acids, specifically L-alanine, on sleep of Drosophila melanogaster. Some amino acids including L-alanine are shown to be attractive to flies. To assess their effect on sleep, either sucrose (sweet) or sorbitol (non-sweet) was used as a base sugar of the food. Sleep was measured using monitors with infrared beams, and feeding behavior was examined by food intake and proboscis extension response tests. L-alanine supplementation in a sweet diet did not alter sleep, but supplementation in a non-sweet diet increased sleep. The addition of non-nutritive sweetener, sucralose to a non-sweet diet also increased sleep, but combining sucralose with L-alanine did not produce additive effects. L-alanine also increased the lifespan of aged flies when supplemented in a non-sweet diet. These findings suggest that the attractive taste properties of L-alanine induced sleep and offer new insights into the relationship between sleep and taste.