Abstract # 187:

Scheduled for Friday, June 19, 2015 06:00 PM-08:00 PM: (Cascade AJBCD) Poster Presentation


THE EFFECT OF TESTOSTERONE ON ATTENTION AND ANXIETY IN ADULT MALE RHESUS MACAQUES (MACACA MULATTA)

A. L. Heagerty, L. A. Houser, M. Marks, S. Murphy, D. H. Gottlieb, O. Varlamov and K. Coleman
Oregon National Primate Research Center, Beaverton, OR 97006, USA
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     Research in humans and macaques indicates that testosterone reduces anxiety elicited by negative social stimuli. Initial research assessing emotional state in nonhuman primates with attention bias testing suggests that those in a negative state attend longer to negative stimuli. We assessed emotional state in response to stimuli using an attention bias paradigm with six surgically castrated and six intact male rhesus macaques. We presented subjects with either a positive photo (e.g., food) or a negative photo (e.g., threat face) paired with a neutral photo for 20 seconds and video-recorded their responses. Subjects were shown 8 positive/neutral and 8 negative/neutral photo pairs. We hypothesized that castrated males would attend longer to negative stimuli and display more anxiety than intact males. Using GLMM regression with Poisson distribution and AIC model ranking we compared time spent looking at photos and frequency of anxiety behaviors between castrated and intact males. Contrary to expectations, castrated males looked at all photo types equally, whereas intact males looked at negative photos longer than neutral or positive photos (B(neutral)=-0.85, p<0.001; B(positive)=-0.90, p<0.001). Additionally, castrated males showed less anxiety (B=-1.01, p<0.001. Testosterone was not associated with decreased anxiety in this study. However, our results are consistent with the hypothesis that testosterone reduces avoidance of negative social stimuli. More work is needed to understand the relationships between testosterone, anxiety, and attention to negative stimuli.