In a project funded by NIH, we found that social challenges elicit both rapid and lasting behavioral effects in the form of enhanced aggressive signaling (singing), and they prime the rest of the organism as well, shifting investment across the brain and body in ways that are adaptive for continued social competition (i.e. consistent with the hypothesis of social priming). For instance, we recently found that prior social instability leaves a lasting mark on the testicular transcriptome to enhance spermatogenesis (Rosvall et al., submitted). These findings are unique because they occur independently of detectable changes in testosterone or corticosterone in circulation, and gene network analyses instead suggest regulation via specific G protein-coupled receptor signaling systems within the testes, including monoamine neurotransmitters. We are working now to understand how past social instability affects the brain as well as other peripheral tissues that are essential to supporting adaptive responses to social competition, such as metabolic function, muscle activity, and immunity.