Abstract # 177:

Scheduled for Friday, August 18, 2006 07:00 PM-09:00 PM: Session 17 (Regency West 1/3 ) Poster Presentation

Does Practice Make Perfect? Maternal Behavioral Interactions and Stress Reactivity in Infants of Primiparous and Multiparous Rhesus Monkeys (Macaca mulatta)

P. G. Roma1, A. M. Ruggiero2, M. L. Schwandt3, J. D. Higley3 and S. J. Suomi2
1American University, Department of Psychology, Washington, DC 20016, USA, 2Laboratory of Comparative Ethology, NICHD, 3Laboratory of Clinical Studies, Primate Unit, NIAAA
     Animal studies have revealed differences in maternal behaviors of primiparous and nulliparous females; less is known about behavioral changes in primiparous versus multiparous females. Moreover, the effects of a mother’s parity on her infants’ biobehavioral development remain largely unexplored. The present study investigated mother-infant behavioral interactions of 19 mother-reared rhesus macaque mothers (Macaca mulatta) and stress reactivity in the first and second infants they reared. Mixed ANOVAs revealed significant main effects of infant age for mutual ventral contact and social contact (ps<.0000005), with paired-samples t-tests confirming significant decreases in mutual ventral and concomitant increases in social from Months 1-2 and 2-3 (ps<.030); however, no effects of parity on grooming, mutual ventral, social, or rejections were observed (ps>.200). Independent samples t-tests revealed no maternal parity-dependent differences in infants’ physiological responses to brief isolation stress (ps>.157), but infants of multiparous mothers did produce higher baseline ACTH at Month 2 (p=.036). During a social separation regimen after Month 6, all infants’ cortisol and ACTH levels were significantly different at adjacent times (Baseline, Hr1, Hr2, Hr96; ps<.01); however infants of multiparous mothers exhibited significantly larger increases in cortisol from Baseline-Hr2 (p=.017) and nearly so between Baseline-Hr1 and Hr1-Hr2 (ps<.056). Maternal behaviors appear unaffected by parenting experience, but differences in infant HPA axis regulation were still observed, suggesting a non-behavioral influence of parity on infant biobehavioral development.