Abstract # 138:

Scheduled for Friday, June 22, 2007 05:00 PM-07:00 PM: Session 14 (South Main Hall) Poster Presentation

Early Infant Care, Hypothalamic-pituitary-adrenal (HPA) Axis Activity, and Pubertal Timing in a Cooperatively Breeding New World Primate, Wied's Black Tufted-ear Marmoset (Callithrix kuhlii)

S. A. Matthews1,2, J. E. Fite1,2, M. Rukstalis1,2, C. N. Ross2,4, A. M. Burrell1,2 and J. A. French1,2,3
1, Department of Psychology, UNOmaha, Omaha, NE 68182-0274, USA, 2Callitrichid Research Center, UNOmaha, Omaha, NE, 68182, USA, 3Department of Biology, UNOmaha, Omaha, NE, 68182-0040, USA, 4School of Biological Sciences, University of Nebraska, Lincoln, 68588-0118, USA
     In human families, the quality and quantity of early parent-daughter interactions are important predictors of pubertal timing in girls. The mechanisms by which parent-daughter relations influence pubertal timing, however, have remained unidentified. In this study, we explored Ellis' (2004) proposition that endocrine stress-systems might mediate the relationship between pubertal timing and parent-offspring interactions. We examined the relationships between marmosets (N=12) pubertal timing, their baseline hypothalamic-pituitary-adrenal (HPA) axis activity (i.e., urinary cortisol excretion), and the care provided to them during the first two weeks of life. Pubertal timing in females and baseline levels of HPA activity during sub-adulthood were negatively correlated with maternal care [r(4)=-0.996, p<0.001 and r(4)=-0.85, p=0.03, respectively]. Pubertal timing was positively correlated with females baseline levels of HPA axis activity during sub-adulthood [r(4)=0.86, p=0.03]. Nonetheless, it was early maternal care and not baseline HPA activity that accounted for a significant portion of variance in pubertal timing [b=-0.31, B=-0.95, t(4)=-9.68, p<0.002]. Pubertal timing in males was positively correlated with paternal care [r(4)=-0.84, p=0.04), but baseline levels of HPA axis activity in males were not related to paternal care or pubertal timing. Therefore, the pubertal timing of both female and male marmosets was related to early parent-offspring interactions, but HPA axis activity could not fully account for the relationship we observed between pubertal timing and early care. Supported by NSF (00-91030) and NICHD (HD 42882).