UC Davis

Adaptation virtually defines survival. For mammals, arguably, no other developmental milestone is exemplified by--nor more reliant on--the sudden and dramatic behavioral alterations observed in the maternal female, which rapidly must undergo change in order to express a large suite of proper and effective maternal behaviors. As pregnancy progresses, as well as during lactation, when pup cues are rich and rampant, the female is literally transformed from an organism that actively avoided offspring-related signals, to one highly motivated by those same cues to build nests, be attracted to pups and to retrieve, group, groom, crouch-over, care for, and protect, the young. Ancillary responses such as reference memory, spatial learning, foraging (including predation), and boldness improve in mothers compared to virgins. Such modifications arise early and are persistent, with neural benefits that last well into senescence. Evolutionarily, such enhancements have likely reduced the maternal burdens associated with sheltering and feeding the vulnerable young; collectively, this strengthens the mother's/parent's reproductive fitness and that of the pups in which all this effort is invested. Of the many behaviors that change as a function of pending or concurrent maternity, therefore, what is the role of modifications to resilience, the ability to withstand the numerous, unpredictable, and threatening environmental events that the mother/parent must daily, indeed, multiply daily, face and thwart in order to bring the offspring from pups to fully functioning adults. We explore these questions, and their connections, here in a multi-disciplinary manner focused on the constellation of change that summates to fundamentally alter the female for the rest of her life. Behavior, brain, neurochemistry and genes are fundamentally changed as the substrate for reproduction unfolds and expresses its inherent plasticity.