EFFECTS OF ORAL YOHIMBINE ON THE PERFORMANCE OF A PERCEPTUAL-MOTOR TASK IN NONHUMAN-PRIMATES

Ethical and practical constraints limit the range of studies that can be performed on patients with anxiety disorders. A nonhuman primate mo del allows for a variety of experimental manipulations that cannot be attempted in humans. In this paper, we report on the further developme nt of a nonhuman primate model of pathological anxiety, which we have labeled acute endogenous distress (AED). Bonnet macaques were challeng ed with the oral admistration of the alpha-2 antagonist, yohimbine. Wh ereas our previous work has documented the behavioral response to yohi mbine provocation, in this paper we report the drug's effects on the m onkey's performance on a novel video computer device that presents wel l defined perceptual-motor tasks of varying difficulty. Under yohimbin e challenge, animals virtually stopped initiating a complex task requi ring sustained attention and perceptual-motor control; however, they s howed no decrease in initiating and performing an easy task under the same pharmacological challenge, thus demonstrating that the effect was cognitive rather than motor in nature.