Abstract # 153:

Scheduled for Friday, June 19, 2015 03:45 PM-04:00 PM: (Cascade H) Oral Presentation


EXTREME BEHAVIORAL PHENOTYPES, HYPOTHALAMIC-PITUITARY ADRENAL AXIS (HPA) ACTIVITY AND ANXIETY IN RHESUS MACAQUES (MACACA MULATTA)

M. Novak1,2, E. J. Peterson2, K. Rosenberg1, E. K. Varner3, J. M. Worlein4, G. H. Lee4, R. U. Bellanca4 and J. S. Meyer1,2
1University of Massachusetts at Amherst, Department of Psychological and Brain Sciences, Amherst, MA 01003-9271, USA, 2Neuroscience and Behavior Graduate Program, University of Massachusetts, 3New England Primate Research Center, Harvard Medical School, 4Washington National Primate Research Center, University of Washington
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     To examine the relationship between extreme phenotypes, stress reactivity, and anxiety in rhesus monkeys, we studied 41 (20 female) monkeys with self-injurious behavior (SIB) and 36 (19 female) age-matched controls at 3 large primate facilities. All monkeys were tested on the Human Intruder Test (HIT), and hair samples were obtained for determining chronic cortisol concentrations. Videotape scoring revealed a second group of 21 (10 female) hyperactive monkeys with locomotor stereotypy (LS), spread across SIB monkeys and controls. Hair cortisol concentrations did not differ among monkeys with SIB alone, LS alone, or controls (neither phenotype). However, monkeys with both phenotypes had significantly higher cortisol levels than the other groups (F(3)=5.08,p<0.01). This effect was only present in males (F(3)=3.49,p=0.02). Monkeys with LS did not differ from non-LS monkeys in their reaction to the HIT. However, LS monkeys showed two distinct responses: suppressors that eliminated their LS in the presence of the intruder, and non-suppressors. Male suppressors had higher levels of cortisol (F(2)=6.49,p<0.01), and all suppressors showed higher threat responses during the stare phase compared to non-suppressors (?2(2)=7.81,p=0.02). Suppressors also looked more in the direction of the intruder during the profile (?2(2)=5.86,p=0.05) and stare (?2(2)=6.90,p=0.03) phases. These results reveal a complex relationship between behavioral phenotypes and HPA activity in which pacing may serve to moderate the behavioral and physiological effects of stress in the non-suppressing animals. NIHGrant R24OD011180.