Meeting Abstract
Early life environmental stressors have the potential to disrupt development in ways that could severely impact fitness. However, the mechanisms by which the stressors affect reproductive physiology and behavior are not well understood. The timing of an environmental stressor is critical in determining the effect on an organism’s life, and treatment with lipopolysaccharide (LPS), a cell wall component of gram-negative bacteria, is commonly employed to induce an immune response. Despite what is known about the effects of sickness on reproduction, the precise physiological mechanisms have not yet been determined. The goal of this study was to investigate the effects of a neonatal immune challenge on subsequent adult reproductive physiology and associated behaviors, and the possible neuroendocrine mechanisms mediating these effects. Hamsters were housed in a 16:8 light:dark photoperiod and received LPS or saline injections on pnd 3 and 5, as there is heightened sensitivity of the GnRH pulse generator at these time points. Body mass and food intake were tracked throughout the study. Vaginal patency (females) was recorded and estimated testis volume (males) was calculated to track onset of reproductive maturity. Animals were placed in staged mating pairs with reproductively mature individuals of the opposite sex at pnd75, during which a series of behaviors were scored. Animals treated with LPS showed changes in food intake, body weight, and reproductive organ mass, as well as timing of reproductive maturity. Reproductive behaviors and other associated social behaviors were affected by LPS injections. Collectively, the results of this study will contribute to a greater understanding of how the neuroendocrine and immune systems interact during development.
