Behavioural profiles in captive-bred cynomolgus macaques: towards monkey models of mental disorders?

PLoS One. 2013 Apr 29;8(4):e62141. doi: 10.1371/journal.pone.0062141. Print 2013.

Abstract

Background: To date, experimental and preclinical studies on neuropsychiatric conditions have almost exclusively been performed in experimentally-induced animal models and have only rarely relied upon an ethological approach where animals have been observed in more naturalistic settings. The laboratory species of choice has been the rodent while the potential of more closely-related non-human primates have remained largely underexplored.

Methods: The present study, therefore, aimed at investigating the possible existence of spontaneous atypical/abnormal behaviours displayed by 40 cynomolgus macaques in captive conditions using an unbiased ethological scan-sampling analysis followed by multifactorial correspondence analysis and a hierarchical clustering.

Results: The study identified five distinct profiles (groups A to E) that significantly differed on several behaviours, body postures, body orientations, gaze directions and locations in the cage environment. We suggest that animals from the low n groups (D and E) present depressive-like and anxious-like symptoms, reminiscent of depressive and generalized anxiety disorders. Inter-individual differences were highlighted through unbiased ethological observations of spontaneous behaviours and associated parameters, although these were not associated with differences in plasma or cerebrospinal fluid levels of either stress-related hormones or monoamines, i.e. in accordance with the human situation.

Conclusions: No interventional behavioural testing was required to discriminate between 3 typical and 2 atypical ethologically-defined behavioural profiles, reminiscent of certain depressive-like and anxiety-like symptoms. The use of unbiased behavioural observations might, thus, allow the identification of animal models of human mental/behavioural disorders and their most appropriate control groups.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adrenocorticotropic Hormone / blood
  • Adrenocorticotropic Hormone / cerebrospinal fluid
  • Animals
  • Anxiety / blood
  • Anxiety / cerebrospinal fluid
  • Anxiety / physiopathology*
  • Anxiety / psychology
  • Behavior, Animal
  • Biogenic Monoamines / blood
  • Biogenic Monoamines / cerebrospinal fluid
  • Breeding
  • Cluster Analysis
  • Depression / blood
  • Depression / cerebrospinal fluid
  • Depression / physiopathology*
  • Depression / psychology
  • Depressive Disorder / blood
  • Depressive Disorder / cerebrospinal fluid
  • Depressive Disorder / physiopathology*
  • Depressive Disorder / psychology
  • Disease Models, Animal
  • Hydrocortisone / blood
  • Hydrocortisone / cerebrospinal fluid
  • Macaca fascicularis / psychology*
  • Male
  • Posture

Substances

  • Biogenic Monoamines
  • Adrenocorticotropic Hormone
  • Hydrocortisone

Grant support

This work was supported by ANR-08-MNP-018 MCHPRIMAPARK Agence Nationale de la Recherche grants (EB), Biothèque Primate - Centre National de la Recherche Scientifique Life Sciences Department (EB), and an unrestricted grant from Motac Neuroscience Ltd. (UK). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.