Abstract # 4485 Event # 110:

Scheduled for Friday, June 21, 2013 11:15 AM-11:30 AM: Session 12 (Auditorium) Oral Presentation


CORTISOL AND ENERGY IN MOTHER’S MILK PREDICT INFANT TEMPERAMENT: A COMPLEX SYSTEM

K. J. Hinde1,2,3 and J. P. Capitanio2,4
1Department of Human Evolutionary Biology, Harvard University, Dept Hum Evol Biol, Cambridge, Massachusetts 02138, USA, 2California National Primate Research Center, UC Davis, 3Nutrition Lab, Smithsonian National Zoological Park, 4Department of Psychology, University of California
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     Glucocorticoids and available energy in milk have been associated with infant temperament, but to date no study has investigated both aspects of milk simultaneously. We hypothesize that temperament is organized in concert with the metabolism by energetic conditions during early development as well as through “lactocrine programming” from hormones in mother’s milk. Using Macaca mulatta mother-infant dyads (N=108) from the California National Primate Research Center, we investigated milk cortisol and available milk energy from early to peak lactation and the association with infant ‘Confident’ and ‘Nervous’ temperament. Using multiple regression, we found that mother’s milk was predictive of infant temperament in general, but the important parameters were not the absolute milk values. Instead, changes in milk constituents from early to peak lactation were retained during AIC model selection. Moreover the magnitude of these effects differed between sons and daughters; sons were much more sensitive to changes in mother’s milk across time. For example, sons were more Nervous when cortisol and milk energy increased from early to peak lactation (p=0.003 and p=0.002, respectively) and if they had slower growth (p<0.008) (full model with all control variables adjR2 =0.38, N=47). In adulthood the HPA axis, metabolism, and behavior do not exist apart from one another. Our results suggest that the organization of these interconnected systems is likely shaped, in part, by mother’s milk during ontogeny.