How does brain coordinate physiological and behavioral responses to achieve survival in adverse environment is intriguing yet complicated. During studies of the small G protein Rac's role in learning and memory, the authors unexpectedly observed that neuronal expression of dominant-negative Rac in adult Drosophila remarkably enhanced the survival of animals in various stress conditions, including oxidation, desiccation, starvation, and heat. The elevated stress resistance was not accompanied by a reduction in female fecundity or a change in whole-body lipid storage. The observation therefore implies the involvement of small G protein Rac in neuronal regulation of global stress responses.