title: Anxiogenic effects of developmental bisphenol A exposure are associated with gene expression changes in the juvenile rat amygdala and mitigated by soy.
abstract: Early life exposure to Bisphenol A (BPA), a component of polycarbonate plastics and epoxy resins, alters sociosexual behavior in numerous species including humans. The present study focused on the ontogeny of these behavioral effects beginning in adolescence and assessed the underlying molecular changes in the amygdala. We also explored the mitigating potential of a soy-rich diet on these endpoints. Wistar rats were exposed to BPA via drinking water (1 mg/L) from gestation through puberty, and reared on a soy-based or soy-free diet. A group exposed to ethinyl estradiol (50 µg/L) and a soy-free diet was used as a positive estrogenic control. Animals were tested as juveniles or adults for anxiety-like and exploratory behavior. Assessment of serum BPA and genistein (GEN), a soy phytoestrogen, confirmed that internal dose was within a human-relevant range. BPA induced anxiogenic behavior in juveniles and loss of sexual dimorphisms in adult exploratory behavior, but only in the animals reared on the soy-free diet. Expression analysis revealed a suite of genes, including a subset known to mediate sociosexual behavior, associated with BPA-induced juvenile anxiety. Notably, expression of estrogen receptor beta (Esr2) and two melanocortin receptors (Mc3r, Mc4r) were downregulated. Collectively, these results show that behavioral impacts of BPA can manifest during adolescence, but wane in adulthood, and may be mitigated by diet. These data also reveal that, because ERβ and melanocortin receptors are crucial to their function, oxytocin/vasopressin signaling pathways, which have previously been linked to human affective disorders, may underlie these behavioral outcomes.
authors.affiliation: Department of Biology, North Carolina State University, Raleigh, North Carolina, United States of America. hbpatisa@ncsu.edu
authors.forename: Heather B
authors.initials: HB
authors.lastname: Patisaul
authors.forename: Alana W
authors.initials: AW
authors.lastname: Sullivan
authors.forename: Meghan E
authors.initials: ME
authors.lastname: Radford
authors.forename: Deena M
authors.initials: DM
authors.lastname: Walker
authors.forename: Heather B
authors.initials: HB
authors.lastname: Adewale
authors.forename: Bozena
authors.initials: B
authors.lastname: Winnik
authors.forename: Janis L
authors.initials: JL
authors.lastname: Coughlin
authors.forename: Brian
authors.initials: B
authors.lastname: Buckley
authors.forename: Andrea C
authors.initials: AC
authors.lastname: Gore
mesh_terms: D000679:Amygdala / Q000187:drug effects*; D000818:Animals; D001007:Anxiety / Q000139:chemically induced* / Q000209:etiology*; D001559:Benzhydryl Compounds / Q000009:adverse effects*; D047629:Estrogen Receptor beta / Q000378:metabolism; D005260:Female; D020869:Gene Expression Profiling; D019833:Genistein / Q000494:pharmacology; D018811:Maternal Exposure; D010636:Phenols / Q000009:adverse effects*; D011247:Pregnancy; D011270:Pregnancy, Animal; D051381:Rats; D017208:Rats, Wistar; D044101:Receptors, Melanocortin / Q000378:metabolism; D012727:Sex Characteristics; D013025:Glycine max / Q000187:drug effects*; D014867:Water / Q000737:chemistry; D000098826:Bisphenol A Compounds
chemical_list: D001559:Benzhydryl Compounds; D047629:Estrogen Receptor beta; D019833:Genistein; D010636:Phenols; D044101:Receptors, Melanocortin; D014867:Water; C006780:bisphenol A; D000098826:Bisphenol A Compounds