Female pups receive more maltreatment from stressed dams

Abstract

The effects of exposure to developmental stress often diverge for males and females. Using the scarcity‐adversity model of low nesting resources outside the home cage, our lab has discovered sex differences in both behavioral and epigenetic consequences of repeated exposure to caregiver maltreatment. For the measures we have performed to date, we have found more consequences for females. The reasons underlying this sex disparity are unknown. In the current experiment, we aimed to discern the quality of maternal care received by male and female pups in our model. As we have previously found more behavioral and epigenetic consequences in females, we hypothesized that females receive more adverse care compared to their male littermates. Our hypothesis was supported; in our maltreatment condition, we found that female pups received more adverse care than males. This sex difference in adverse care was not present in our two control conditions (cross‐foster and normal maternal care). These data lend support to the notion that one reason females in our model incur more behavioral and epigenetic consequences is a result of greater mistreatment by the dam.

Preventing epigenetic traces of caregiver maltreatment: A role for HDAC inhibition

“…First, there are sex differences in basal levels of epigenetic modifications (Kurian et al, 2010; Nugent et al, 2015; Tsai et al, 2009) and enzymes (Blaze and Roth, 2013; Kigar et al, 2016; Kolodkin and Auger, 2011; Kurian et al, 2007; Xu et al, 2008a, 2008b), which may affect the female epigenetic response to both maltreatment and epigenome‐modifying drugs. Second, recent data from our lab show that females experience a higher proportion of adverse care in our maltreatment paradigm than do male pups (Keller et al, 2019). Given that male pups are subject to increased nurturing (licking) behavior in the home cage (Moore and Morelli, 1979; Richmond and Sachs, 1984), females subject to our brief exposures of maltreatment are overall experiencing more adverse and less nurturing behaviors than male pups subject to the same exposures.…”

Chemogenetic manipulation of the bed nucleus of the stria terminalis counteracts social behavioral deficits induced by early life stress in C57BL/6J mice

“…Further complicating findings related to rodent sex differences induced by ELS is the fact that rodent dams exhibit greater maternal care for male versus female pups (Hao, Huang, Nielsen, & Kosten, 2011;Keller, Nowak, & Roth, 2019;Moore & Morelli, 1979;Richmond & Sachs, 1984). And as mentioned previously, ELS rodent models produce varied effects depending upon species and strain, so additional future studies specific to C57BL/6J mice will help ascertain whether ELS exerts BNST-mediated effects that are dependent upon sex.…”

Corticotropin-releasing factor infusion in the bed nucleus of the stria terminalis of lactating mice alters maternal care and induces behavioural phenotypes in offspring

“…In addition, it also agrees with previous studies showing that female animals are more vulnerable to the effects of early life stress in a wide range of behavioural and neurobiological outcomes 42 , 43 . According to Keller et al 44 , the increased vulnerability in females may be related to impaired maternal care. These authors showed that in a maltreatment condition, female offspring received higher adverse care from the dams than male offspring.…”