135 | Temporal variation in maternal care of rats induced by limited bedding and nesting paradigm and influence on infant developmental milestones and behavioral profile

Cognition, Behavior, and Memory

Author: Grace E. Pardo | Email: grace.pardo@gmail.com

Grace E. Pardo , Lucero B. Cuevas , Javier Vásquez , Alondra Casas , Enver M. Oruro , Luis F. Pacheco-Otálora

1° Laboratorio de Investigación en Neurociencia, Instituto Científico, Universidad Andina del Cusco
2° Laboratorio de Neurocomputación, Simulación Social y Sistemas Complejos, Instituto Científico, Universidad Andina del Cusco

The alteration of maternal care during the first week of altricial species’ postnatal life impacts the pups’ early developmental milestones. However, whether these neurobehavioral maturational processes are susceptible to alterations of maternal care in specific time windows is unknown. We explored here a temporal variation of maternal care in rats through exposition to the limited bedding and nesting (LBN) paradigm in four temporal windows during postpartum days: 2-4, 5-6, 7-9, and 2-9 and recorded maternal behavior. Likewise, we assessed the developmental milestones of pups on postnatal days 13-14. We found that LBN occurring during the first five days of postpartum induces a significant variation in maternal care. Furthermore, dams with higher maternal care variation in early postpartum have pups with reduced body weight gain but no alteration in the eye-opening day or odor-guided behaviors. The most prolonged LBN protocol was the only one that altered the home-nest odor preference and nipple attachment behavior of pups from both sexes. These results suggest that maternal care is mainly susceptible to alteration in early postpartum days by LBN and impacts somatic pups’ development milestones but not odor-guided behaviors, which are altered by a more prolonged LBN protocol. These results also open a discussion about exploring sensitive periods of development for maternal care influence through the LBN paradigm.