Maternal social environment affects offspring cognition through behavioural and immune pathways in rats

Abstract

The social environment of lactation is a key etiological factor for the occurrence of postpartum disorders affecting women and their children. Postpartum depression and anxiety disorders are highly prevalent in new mothers and negatively affect offspring’s cognitive development through mechanisms which are still unclear. Here, using a rat model, we manipulated the maternal social environment during lactation and explored the pathways through which social isolation (vs. the opportunity for limited social interaction with another lactating female, from 1 day before parturition to postpartum day 16) and chronic social conflict (daily exposure to a male intruder from postpartum day 2 to day 16) affect offspring learning and memory, measured at 40 to 60 days of age. We specifically explored the consequences of these social treatments on two main hypothesized mediators likely to affect offspring neurophysiological development: the quality of maternal care and maternal inflammation factors (brain‐derived neurotrophic factor, granulocyte‐macrophage colony‐stimulating factor, intercellular adhesion molecule 1, tissue inhibitor of metalloproteinases 1 and vascular endothelial growth factor) likely to influence offspring development through lactation. Maternal rats which had the opportunity to interact with another lactating female spent more time with their pups which, in turn, displayed improved working and reference memory. Social stress affected maternal plasma levels of cytokines that were associated with cognitive deficits in their offspring. However, females subjected to social stress were protected from these stress‐induced immune changes and associated offspring cognitive impairment by increased social affiliation. These results underscore the effects of social interaction for new mothers and their offspring and can be used to inform the development of clinical preventative measures and interventions.

The social network: Neural control of sex differences in reproductive behaviors, motivation, and response to social isolation

“…Social isolation also produces sexually dimorphic responses when it comes to sexually dimorphic reproductive behaviors. The social isolation of lactating female mice and rats reduced the duration of maternal care [ 161 , 162 ], while the isolation of male mice actually induced paternal behaviors toward unfamiliar pups and, in line, reduced their typical infanticide response [ 163 , 164 ].…”

Cognitive changes mediated by adenosine receptor blockade in a resveratrol-treated atherosclerosis-prone lupus mouse model

“…Elevated ICAM-1 in the brain has been shown in other murine neurolupus models. 53 Previous work has shown that high levels of ICAM-1 are detrimental to cognition 47 , 48 , 49 but again, this relationship is not clear-cut and neurolupus mice given anti-ICAM antibodies did not show attenuation of inflammation in the choroid plexus. 50 …”