Stability of parental care across siblings from undisturbed and challenged pregnancies: Intrinsic maternal dispositions of female rhesus monkeys.

Abstract

The concept of fetal programming is based on the idea that the developmental trajectory of infants is adjusted in response to in utero conditions. In species with extended parental care, these prenatally-derived tendencies are further substantiated by behavioral attributes of the mother during the postnatal period. We investigated the stability of maternal behavioral interactions with infant monkeys, and carefully varied prenatal conditions across siblings reared by the same mother. We hypothesized that effects of prenatal disturbance and the infant’s susceptibility would be differentially affected by maternal attributes. Hierarchical Linear Modeling was employed to analyze observational data on 121 rhesus macaques reared by a total of 35 multiparous mothers. A portion of the variance in 5 dyadic behaviors was statistically driven by the infant (or was unique to a particular mother-infant pair), but stable maternal propensities and a consistent style of care across siblings also substantially influenced behavioral interactions. Moreover, the magnitude and direction of the prenatal effects were contingent on a female’s intrinsic dispositions. When mothers typically exhibited high levels of a corresponding behavior, responsiveness to infants was enhanced as a consequence of prenatal disturbance. The opposite was true for less expressive females. Challenges to the wellbeing of pregnancy thus served to accentuate maternal predispositions and served to magnify the range of variation in mother-infant behavior across the whole population.

Hormone levels in neonatal hair reflect prior maternal stress exposure during pregnancy

“…The prenatal stress condition involved a controlled disturbance induced with an acoustical startle protocol (Coe et al, 2003; Shirtcliff et al, 2013). Briefly, 5 days a week for 5 weeks, or 20% of the 24-week pregnancy, the gravid female was relocated to a darkened room where a computer program randomly broadcast 3 loud noises (1 sec, 110 dB) during a 10-min period.…”

Proteobacteria abundance during nursing predicts physical growth and brain volume at one year of age in young rhesus monkeys

“…Mother‐infant interactions were observed through 4 months of age, spanning the primary period of nursing. The observations focused on feeding behavior and the development of autonomy, 38 with predefined behaviors scored in 5 minutes sessions 12 times per month. Time spent in contact with the mother or suckling was contrasted with time exploring the environment or eating solid foods as an index of autonomy.…”