Abstract # 915 Poster # 168:

Scheduled for Friday, August 19, 2005 07:00 PM-09:00 PM: (Cambridge/Oxford Room) Poster Presentation


REARING CONDITION AND FLUCTUATING ASYMMETRY LEVELS IN INFANT RHESUS MACAQUES

M. L. Schwandt1, K. Ladd1, S. Higley2, S. J. Suomi2 and J. D. Higley1
1NIH/NIAAA, Laboratory of Clinical and Translational Studies, Section on Comparative Primate Psychopathology, PO Box 529, Poolesville, MD 20837, USA, 2NIH/NICHD, Laboratory of Comparative Ethology
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     Fluctuating asymmetry (FA), or small, random deviations from perfect bilateral symmetry, is a measure that is particularly susceptible to environmental stress. Based on the assumption that primate infants reared in the nursery without their mothers experience increased levels of early life stress, we tested the hypothesis that rhesus macaque infants reared under conditions of peer-only (PR) or surrogate peer-rearing (SPR) would exhibit higher levels of FA than mother-reared (MR) infants. Length measurements of the upper arm, forearm, hand, thigh, leg, and foot were collected from 39 infants (15 MR, 16 PR, and 8 SPR) at 60 days of age. Two replicate measurements were made for each trait on each side (right vs. left) using digital calipers. Results indicated that 1) between-side variance was significantly greater than measurement error for all traits, 2) between-side variance was not dependent upon trait size, and 3) only one trait, leg, showed directional asymmetry. Contrary to our hypothesis, no significant differences between rearing conditions were found for FA across multiple traits (two-way rearing x trait ANOVA, P = 0.9266) or for a composite FA measure (sum of |R-L| for each trait; ANOVA, P = 0.8404). These results suggest that rhesus monkey infants raised in a nursery environment do not exhibit disruptions of the physical developmental process as reflected in elevated levels of FA.