Abstract # 189:

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


L. A. Houser, K. Coleman and O. Varlamov
Oregon National Primate Research Center, 505 NW 185th Ave, Beaverton, OR 97006, USA
     While a great deal of emphasis has been placed on the effects of estrogen on mood and cognition, less is known about the role of testosterone. Studies examining testosterone on cognitive function have had mixed results. We examined whether testosterone affected trainability in 11 adult, male rhesus macaques (Macaca mulatta). Five monkeys were castrated and the other 6 underwent a sham castration surgery, and all were on a high fat diet as part of an unrelated study. Approximately 4 months after surgeries, we trained the monkeys to touch a target (PVC elbow hung on the cage) and remain stationary in the front of their cage and present for injection using positive reinforcement training techniques. We calculated time it took to reliably complete each task, i.e., perform on command for three consecutive training sessions. Animals were trained 2-3 times per week for a total of 20 sessions. While all subjects learned to reliably touch the target, it took significantly fewer sessions to train the intact compared to castrated males (Mann Whitney U=6.5, p=0.02). The intact animals were more likely than castrated subjects to present their hindquarters (chi square=4.4, df=1, p=0.036). Five of the intact males (83%) compared to one castrated male learned this task. These data suggest that testosterone may have a role in training success, at least for these relatively simple tasks.