Neuroanatomical Reprogramming Produced By Perinatal Exposure to Indoor Flame Retardants (PBDEs) May Underlie Abnormal Affective/Social Behavior

Abstract

Polybrominated diphenyl ethers (PBDEs) are flame retardant pollutants with adverse neurobehavioral effects. In this study, we examined affective and social behaviors in male offspring of pregnant/lactating mothers exposed to a penta‐BDE mixture DE‐71 (low dose (LD) (0.1 mg/Kg/day), high dose (HD) (0.4 mg/Kg/day), corn oil vehicle (control). LD exposure significantly decreased pup litter size which may be associated with changes in dam parameters in gestation. Adult offspring were subjected to behavioral testing that measure social memory, sensorimotor integration/anxiety and depressive like behavior: Social Recognition Task (SRT), SUOK and forced swim tests (FS). HD male offspring showed abnormal SRT ability showing no preference for novel over familiar stimulus mice as compared to control (p<.0001). For SUOK test HD males showed significantly less falls/segments crossed relative to control (p=.024), indicating altered sensorimotor ability. For FS, LD mice spent significantly less time immobile compared to control (p=.002), suggesting that PBDE exposure alters affective behavior and/or promotes hyperactivity. To examine altered neurodevelopment that may underlie behavioral results, we examined intraneocortical connections (INCs) in male offspring at postnatal day 7 (PN7). DiI and DiA fluorescent dyes were injected into the frontal and visual cortices, respectively and dyes were localized to cell layers containing the cells with fibers projecting to dye projection zones (DPZs). DiI and DiA tracing revealed significantly wider normalized DPZs over the visual cortex in LD (p=.04, n=3–8 per group): control 37%, LD 53%, HD 48%. A similar but insignificant change was observed in HD. Frontal association cortex DPZ showed an apparent increase in HD (p=.09, n=3–7 per group): control 47%, LD 53%, HD 57%. The larger dye distribution in LD offspring is not due to gross anatomical differences (cortical length). These results suggest that PBDEs may produce changes in affective behavior in LD male offspring, in part, by altering neurodevelopment of the neocortex.Support or Funding InformationSupported by APS (L.A.), UCMEXUS (E.K.,) UCR Chancellor's Research Fellowship (J.K), DOE HSI‐STEM Fellowship (E.K, N.H ).This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.