Non-human primate models for investigating fear and anxiety.

Non-human primates exhibit similar physiological and behavioral responses to anxiety-inducing situations as humans and have, in fact, been successfully employed in both conditioned (i.e. conflict paradigms) and ethologically based tests of fear/anxiety (i.e. involuntary isolation, social interaction, human threat, predator confrontation). In the last decade, a renewed and growing interest in non-human primate models has resulted from the use of the small callitrichid species in behavioral pharmacology and neuroscience. This review focuses on the available non-human primate models for investigating fear/anxiety, addressing their advantages, shortcomings, and conceptual framework on which they are based. Lastly, a new ethologically based model to study anxiety and fear-induced avoidance in callitrichids--the marmoset predator confrontation test--is discussed.