The neurochemical effects of stressful events involve a range of adaptive responses to environmental challenges. However, repeated stressors may result in the development of psychopathologies such as anxiety and depression. The immune signaling molecule, pro-inflammatory cytokines, has been linked to the development of such illnesses. Interestingly, distinct differences in stressor responsiveness exist between the sexes, alongside a much higher rate of affective disorders in females. In the present experiments we examined if repeated exposure to stressors would impact male and female CD-1
mice differently with respect to behaviour as well as cytokine expression. Repeatedly stressed males demonstrated impulsive behaviour along with sensitized IL-1β expression. In follow-up experiments the role of 17β-estradiol was examined, with stressed males that were exposed to estrogen showing reduced TNF-α expression while similarly treated females had a drastic elevation in IL-6. The current results demonstrate the differences in the stressor response system between the sexes.