Neuroendocrine Consequences of Exposure to Estrogenic Compounds

Disruption of the reproductive neuroendocrine system by exposure to environmental xenoestrogens during development is likely to manifest as subtle changes in adult behaviors and functions, rather than overt changes in brain anatomy and reproductive physiology.  Therefore, in developing predictive strategies for evaluating the ultimate effects of early exposure to endocrine disruptors in humans, it is critical to employ a comprehensive approach that assesses neuronal function and reproductive physiology across the lifespan.  We and others have found that, in rodents, neonatal exposure to endocrine disruptors such as Bisphenol-A and genistein can affect sexually dimorphic brain morphology and the sex specific development of neuroendocrine pathways with regional and cellular specificity.  These subtle but significant changes are associated with disrupted reproductive behaviors, advanced pubertal onset, premature loss of the estrous cycle and compromised fertility.  The experimental tools and approaches that have traditionally been used by toxicologists to screen compounds for estrogenic effects are not sensitive enough or appropriately geared to detect these subtle types of changes.  Therefore, to adequately conduct human risk assessment, it is imperative that endocrine disruptor screening paradigms be updated to more comprehensively examine the impact of these types of compounds.