Assessing Anxiety in Nonhuman Primates

Abstract

Anxiety can be broadly described as a psychological state in which normally innocuous environmental stimuli trigger negative emotional expectations. Human anxiety disorders are multidimensional and may be organic or acquired, situational or pervasive. The broad ranging nature of the anxiety phenotype speaks to the need for models that identify its various components and root causes to develop effective clinical treatments. The cross-species comparative approach to modeling anxiety disorders in animals aims to understand mechanisms that both contribute to and modulate anxiety. Nonhuman primate models provide an important bridge from nonprimate model systems because of the complexity of nonhuman primates' biobehavioral capacities and their commonalities with human emotion. The broad goal of this review is to provide an overview of various procedures available to study anxiety in the nonhuman primate, with a focus on the behavioral aspects of anxiety. Commonly used methods covered in this review include assessing animals in their home environment or in response to an ethologically relevant threat, associative conditioning and startle response tests, and cognitive bias tests. We also discuss how these procedures can help veterinarians and researchers care for captive nonhuman primates.

Neonatal perirhinal cortex lesions impair monkeys’ ability to modulate their emotional responses.

“…Compared with other tests of emotional reactivity, the HI task is better suited for longitudinal testing of monkeys, since monkeys do not seem to habituate to repeated exposures to the task (Kalin & Shelton, 1998). The HI task is designed to assess emotional reactivity to a social stressor (Kalin, 1993), and the modulation of emotional behavior to different levels of social threat based on the gaze direction of an unfamiliar human [reviewed in (Coleman & Pierre, 2014)]. In addition, the HI task has been shown to rapidly activate the HPA axis and stimulate the release of glucocorticoids (Jahn et al, 2010; Kalin, Larson, Shelton, & Davidson, 1998; Kalin, Shelton, Davidson, & Kelley, 2001; Raper et al, 2013a; Raper et al, 2013b).…”

The dot-probe task to measure emotional attention: A suitable measure in comparative studies?

“…In nonhuman primates, it is hard to determine whether the individuals differ in their anxiety levels, or in any other personal traits, yet there are some possible ways to assess anxiety in nonhuman primates (for a review, see Coleman & Pierre, 2014). Examples are provoked response tests, associative conditioning and startle response tests and cognitive bias tests.…”

Isoflurane Anesthesia Has Long-term Consequences on Motor and Behavioral Development in Infant Rhesus Macaques

“…34,35 is one of the most commonly used tests to assess anxiety and the related temperamental trait of behavioral inhibition in young macaques. 30 This test was used to measure behavioral responses in three situations: being alone in a novel cage, being in the presence of a human stranger whose gaze was diverted (a potentially threatening stimulus), and being in the presence of a human stranger making direct eye contact (an overt threat).…”

“…For raw p-values less than 0.05, we report the BenjaminiHochberg adjusted p value (q) as well. Because an individual's response to one stimulus does not necessarily predict how it will respond to other stimuli 30 , we utilized the Benjamini-Hochberg within each testing paradigm (i.e., IBAS testing, response to provocative tests, home cage testing). Post hoc comparisons (using the Tukey or its nonparametric equivalent, the Nemenyi test), were carried out on significant findings.…”