BPS, found in baby bottles, personal care products and thermal receipts, is a replacement chemical for BPA and was introduced when concern was raised about possible health effects of that plastic compound. As with BPA, there is evidence that BPS is an endocrine disruptor.
In the first study of its kind, environmental health scientist Laura Vandenberg and neuroscientist Mary Catanese at the University of Massachusetts Amherst examined the effects of the compound bisphenol S (BPS) on maternal behavior and related brain regions in mice. They found subtle but striking behavior changes in nesting mothers exposed during pregnancy and lactation and in their daughters exposed in utero.
Estrogenic endocrine disrupting chemicals (EDCs) have been shown to disrupt maternal behavior in rodents. We investigated the effects of an emerging xenoestrogen, bisphenol S (BPS), on maternal behavior and brain in CD-1 mice exposed during pregnancy and lactation (F0 generation) and in female offspring exposed during gestation and perinatal development (F1 generation).
BPS affects maternal behavior as well as maternally relevant neural correlates
We observed different effects in F0 and F1 dams for a number of components of maternal behavior including time on the nest, time spent on nest-building, latency to retrieve pups, and latency to retrieve the entire litter. We also characterized expression of estrogen receptor (ER) alpha (α) in the medial preoptic area (MPOA) and quantified tyrosine hydroxylase (TH) immunoreactive cells in the ventral tegmental area (VTA), two brain regions critical for maternal care. BPS-treated females in the F0 generation had a significant increase in ERα expression in the caudal subregion of the central MPOA (cMPOA) in a dose dependent manner. In contrast, there were no significant effects of BPS on the MPOA in F1 dams or the VTA in either generation.
Uncovering effects of environmental chemicals that might influence proper maternal care have broad social and public health implications
This work demonstrates that BPS affects maternal behavior and brain with outcomes depending on generation, dose and postpartum period. Many studies examining effects of EDCs view the mother as a means by which offspring can be exposed during critical periods of development. Here, we demonstrate that pregnancy and lactation are vulnerable periods for the mother. We also show that developmental BPS exposure alters maternal behavior later in adulthood. Both findings have potential public health implications.