Stress induces equivalent remodeling of hippocampal spine synapses in a simulated postpartum environment and in a female rat model of major depression

Highlights • Postpartum stress causes a loss of hippocampal spine synapses. • Pregnancy levels of ovarian hormones prevent the synaptolytic effect of stress. • This preventive effect of ovarian hormones is mediated by reduced stress responsiveness. • These data provide further support for the “synaptogenic hypothesis” of depression.