Investigating the effects of early life experience on the response to acute stress in adulthood (#377)
Early life experience shapes the developmental trajectory of the brain and may also affect plasticity of the brain in adulthood. In the rat, maternal care in the form of anogenital licking and grooming (LG) modulates hippocampal levels of glucocorticoid receptors and baseline levels of neurogenesis; however, the effects of maternal care on an individual’s response to adult stress are less understood. Recent work from our lab has demonstrated that an acute stressor (3 hour immobilization) increases cellular proliferation in the dorsal dentate gyrus of the adult male rat and that the activation of the newborn neurons is coincident with enhanced fear extinction memory1. Therefore, in this study, we investigate the hypothesis that early life adversity in the form of low maternal care attenuates the offspring’s response to acute stress. In addition, we investigate maternal care’s effects on hippocampal neurogenesis after acute stress at puberty as well as sex differences at both time points. Maternal care was monitored from post-natal days (PND) 1-7, and the offspring of high or low LG mothers were subjected to 3 hours of immobilization stress either at puberty (PND35) or adulthood (PND90). Animals were perfused immediately following immobilization stress for quantification of cell proliferation in the dentate gyrus. Preliminary data will be presented that show maternal care modulates the proliferative effects of acute stress on the hippocampus and that sex differences in these measures exist at both time points. Collectively, these results will shed light on the effects of maternal care on offspring’s stress reactivity and its consequences for adult learning and memory.
- Kirby, E., Muroy, S., Sun, W., Covarrubias, D., Leong, M., Barchas, L., Kaufer, D., 2012. Acute stress enhances adult rat hippocampal neurogenesis and activation of newborn neurons via secreted astrocytic FGF2. eLife.