Abstract # 2751 Poster # 39:

Scheduled for Saturday, September 19, 2009 06:30 PM-09:00 PM: Session 5 (Mission Bay Ballroom CDE) Poster Presentation


SELF INJURY AND THE INTRUDER CHALLENGE PARADIGM: A COMPARATIVE STUDY EXAMINING GENOTYPE, HORMONAL, AND BEHAVIORAL INTERACTIONS IN LABORATORY RHESUS MACAQUES

S. M. Day1, J. M. Pingel1, M. L. Schwandt2, S. G. Lindell2, E. Davis3, C. S. Barr2, S. J. Suomi3 and J. D. Higley1
1Brigham Young University, Department of Psychology, Provo, Utah 84602, USA, 2NIH Animal Center, NIAA, LCTS, Poolesville, MD 20837, 3NIH Animal Center, NICHD, LCE, Poolesville, MD 20837
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Self injurious behavior (SIB) affects approximately 10% of the rhesus laboratory population. Using the Intruder Challenge test developed by Fairbanks [2001], 145 rhesus macaques (Macaca mulatta) with a mean age of 4.9 years were tested for their response to a stressful social challenge; 14 had a history of self-biting (SB). Blood samples and DNA were obtained to determine serotonin transporter genotype and concentrations of adrenocorticotropic hormone (ACTH). T-Tests [α=0.05] showed that SB monkeys expressed significantly higher frequencies of stereotypies, distress vocalizations and noncontact aggression towards their cagemates. They exhibited significantly lower levels of social grooming, and received less contact aggression from their cagemates, but exhibited significantly more aggression toward the intruder. The data were also analyzed for the effects of serotonin transporter gene genotype (LL and LS) using ANOVA [α=0.05], with SB. Differences between SB and normals were dependent on genotype, with SB monkeys with the LL genotype showing significanly higher ACTH levels and significantly more stereotypies than subjects with the LS genotype and the non-SB monkeys. The LS SB monkeys also exhibited significanly higher rates of vocalizations, locomotion, and risk taking (as measured by the frequency to approach the intruder) than both their LL and non-SB counterparts. These findings suggest an SIB disassociation between the behavioral and hormonal (ACTH) expressions to stress that are dependent on genotype.