eLife assessment
In the current study, the authors describe how sex and age affect the consequence of traumatic brain injury in Drosophila. They find that females are more sensitive than males, and mated females are sensitive whereas virgin females are not. This fundamental work substantially advances our understanding of how sex-dependent response to traumatic brain injury occurs, by identifying the Sex Peptide and the immune system as modulators of sex differences. The authors provide a compelling set of results, showing that female Sex Peptide signaling in Drosophila adversely affects late-life neurodegeneration after early-life exposure to repetitive mild head injury.