Effects of housing conditions on behaviors and biochemical parameters in juvenile cynomolgus monkeys (<i>Macaca fascicularis</i>)

Abstract

To investigate the effects of environmental enrichment on laboratory monkeys, we studied behavioral and physiological differences following changes in housing conditions. Ten male and female juvenile cynomolgus monkeys were first housed in pairs for 8 weeks after quarantine/acclimatization (singly housed) and subsequently housed alone for the next 8 weeks. Monkeys were subjected to evaluations of body weight gain, stereotypic or affiliative behaviors, cortisol, 4-ethylphenyl sulfate (4EPS) and catecholamine concentrations in biological samples, and blood chemistry tests under both housing conditions. Under paired housing, the stereotypic behavioral score decreased in both sexes, and the affiliative behavioral score increased in males and showed an increasing trend in females. Under single housing, the stereotypic score increased in both sexes, and the affiliative score decreased in males. Paired housing decreased serum calcium and urine cortisol concentrations in both sexes and decreased plasma cortisol in males and plasma 4EPS concentrations in females. The stereotypic score was positively correlated with serum calcium, plasma and urine cortisol, and plasma 4EPS concentration and negatively correlated with the affiliative score. The feces painting score, affiliative score, and plasma cortisol and serum calcium concentrations showed sex differences, suggesting differences in responsiveness to environmental changes between males and females. In conclusion, paired housing improved behavioral abnormalities in juvenile cynomolgus monkeys, suggesting that it may be an effective environmental enrichment paradigm. Calcium, cortisol, and 4EPS concentrations in biological samples may be useful indices for evaluating the effects of environmental enrichment.

Paracrine-endocrine FGF chimeras as potent therapeutics for metabolic diseases

“…These changes in appetite in FGF1 HBS -FGF21 C-tail treated animals were accompanied by slight changes in body weight relative to pre-treatment (Table S7). We also noted some weight loss in the saline control group, possibly ascribable to environmental stress; similar phenomena have been reported in previous studies [56].…”

A gut-derived metabolite alters brain activity and anxiety behaviour in mice

“…Gut bacteria can synthesize classical neurotransmitters such as dopamine, norepinephrine, serotonin and gamma-aminobutyric acid, and the production of novel classes of neuroactive metabolites by the microbiome has been postulated 34 . Molecules with phenolic structures similar to 4EP(S) are dysregulated in several preclinical models of behavior 8,35,36 as well as in certain neuropsychiatric disorders [37][38][39][40][41] . Intriguingly, a metabolite of tyrosine closely related to 4EP, p-cresol, has been suggested to influence oligodendrocyte function and affect social and depression-like behaviors in mice 6,42 .…”

Stereotype and abnormal behaviour in Macaca fascicularis captive: Towards good environmental enrichment for its sustainability

“…Besides, based on the review result found that the factor related to stereotypes and abnormal behaviour exhibited, such as former or origin of species adoption (from Topeng Monyet or dancing monkey) (Ai, 2015;Li, 2015), behavioural experiment study (Goossens et al, 2008;Kaeser et al, 2014), social manipulation (Kaplan et al, 2002;C. K. Lutz, 2018;Minami, 1996), and environmental enrichment manipulation (Cannon et al, 2016;Koyama et al, 2019). Based on these…”

“…Commonly known as environmental enrichment (Kerridge, 2005) or captive condition (Mallapur & Choudhury, 2003), as well as in the zoo-living condition, also probable to have some stereotyped behaviour (Birkett & Newton-Fisher, 2011;Hosey, 2005;Jacobson et al, 2016). Besides, one of the primates' taxa was reported for stereotyped and abnormal behaviour, such as macaques (Koyama et al, 2019;Paulk et al, 1977;Vandeleest et al, 2011). The macaque was evenly used in laboratory experiments (Abee et al, 2012) that correlated with a captive or restricted living area condition (Sajuthi et al, 2016), so for this reason, the chance to have some stereotyped and abnormal behaviour is also possible.…”