From Stimulants to Stressors: Chemical Modulation of Development, Physiology, and Behavior in Drosophila melanogaster

Drosophila melanogaster continues to be a tractable and genetically versatile model for dissecting the complex interplay between chemical exposures and biological systems. In this review, we examine how a broad spectrum of chemical agents---including psychoactive compounds, metabolic disruptors, endocrine modulators, and other bioactive xenobiotics---modulate developmental trajectories, neurophysiological functions, and behavioral phenotypes in Drosophila. We synthesize findings from studies employing transcriptomic, proteomic, genetic, and functional approaches to highlight conserved molecular pathways affected by compounds such as caffeine, ethanol, bisphenols, organophosphates, and emerging contaminants. Particular attention is given to chemical-induced alterations in neurodevelopment, synaptic connectivity, circadian regulation, mitochondrial function, oxidative stress responses, and reproductive fitness. Collectively, the evidence underscores the growing relevance of Drosophila in translational chemical biology, especially for high-throughput functional screening and systems-level toxicological investigations. These insights enhance our understanding of chemically induced perturbations at the organismal level and position Drosophila melanogaster as a powerful proxy for probing conserved, human-relevant toxicodynamic mechanisms.