Koyama Hironari, Tachibana Yuki, Takaura Kaoru, Takemoto Shigetoshi, Morii Kiyoshi, Wada Sou, Kaneko Hayato, Kimura Mayuko, Toyoda Atsushi
Laboratory Animal Science Division, Astellas Research Technologies Co., Ltd., 21 Miyukigaoka, Tsukuba-shi, Ibaraki 305-8585, Japan.
United Graduate School of Agriculture Science, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509, Japan.
Exp Anim. 2019 May 8;68(2):195-211. doi: 10.1538/expanim.18-0114. Epub 2018 Dec 21.
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.
为了研究环境丰富化对实验猴的影响，我们研究了饲养条件改变后的行为和生理差异。十只雄性和雌性幼年食蟹猴在检疫/适应环境（单独饲养）后首先成对饲养8周，随后在接下来的8周单独饲养。在两种饲养条件下，对猴子进行体重增加、刻板或亲和行为、皮质醇、生物样品中4-乙基苯基硫酸盐（4EPS）和儿茶酚胺浓度的评估以及血液化学测试。在成对饲养条件下，两性的刻板行为评分均下降，雄性的亲和行为评分增加，雌性呈上升趋势。在单独饲养条件下，两性的刻板评分均增加，雄性的亲和评分下降。成对饲养降低了两性的血清钙和尿皮质醇浓度，降低了雄性的血浆皮质醇和雌性的血浆4EPS浓度。刻板评分与血清钙、血浆和尿皮质醇以及血浆4EPS浓度呈正相关，与亲和评分呈负相关。粪便涂抹评分、亲和评分以及血浆皮质醇和血清钙浓度存在性别差异，表明雄性和雌性对环境变化的反应存在差异。总之，成对饲养改善了幼年食蟹猴的行为异常，表明它可能是一种有效的环境丰富化模式。生物样品中的钙、皮质醇和4EPS浓度可能是评估环境丰富化效果的有用指标。
