12207 A Two-hit Model Of Pcb Exposure And Immune Challenge, And Effects On Behaviors In Rats

Abstract

Abstract Disclosure: S.E. Khoury: None. A. Hynes: None. L.K. Davis: None. L. Thompson: None. K. Sanchez: None. L. Fonken: None. A.C. Gore: None. This study evaluated how two common life experiences: exposures to environmental endocrine-disrupting chemicals (EDCs), and immune challenges, can act independently or in combination to affect social and anxiety-like behaviors in rats. The class of endocrine-disrupting chemical (EDC) used was polychlorinated biphenyls (PCBs), a family of industrial chemicals that, despite their ban in the 1970s, are detectable in the body tissues of virtually all humans and animals today due to their persistence. Exposures to PCBs were given prenatally and in early postnatal life through feeding of rat dams, during hormone sensitive periods of brain development in the offspring. The immune challenge was given postnatally during adolescence through injection of lipopolysaccharide, to induce neuroinflammation. These challenges are individually associated with increased behavioral disorders in humans and rodent models, but how they interact is unknown. In this 2x2 design, rats received either PCBs or oil in early life, and LPS or saline in adolescence. The animals were then tested in a series of behavioral assays to assess for social and anxiety-like behaviors, including Open Field (OF), Juvenile Social Exploration (JSE), Three Chamber Social Test (TCST), Light Dark Box (LD), and Elevated Plus Maze (EPM). An effect of PCB was observed in OF center time. Interactions of EDC and LPS were found in aspects of EP, and TCST. Further work examining protein and gene expression in the hippocampus and hypothalamus is in progress and will help to elucidate the underlying biological mechanism of the observed behavioral changes. Presentation: 6/3/2024