Abstract

The aim of this study was to investigate the behavioral, immunological, and neurological effects of long-term isolation in an animal model. Male C3H/eB mice wereraised in either social isolation or standard conditions for 6 weeks. At 10 weeks, each group was further divided into 3 sets. (A) Physical strength and behavior were evaluated with the grip strength, hot plate, staircase, and elevated plus-maze tests. Natural-killer cell activity and lymphocyte proliferation were measured. (B) Half the animals were subjected to electric shock with 3 reminders, and freezing time was evaluated at each reminder. Cortisone levels were evaluated after 16 weeks. (C)Mice were injected with 38 C-13 B lymphoma cells and followed for tumor size and survival. Strength evaluation yielded asignificantly lower body weight and grip strength in the socially isolated mice. Behavioral test results were similar in the two groups. The pattern of reactions to stress conditioning differed significantly, with the socially isolated mice showing an incline in freezing with each successive reminder, and the control mice showing a decline. The socially isolated mice had significantly attenuated tumor growth, with no significant difference in survival from control mice. There were no significant between-group differences in immunological parameters. In conclusion, social isolation serves as a model for chronic stress. It was associated with significant changes in stress conditioning reaction, resembling symptoms of post-traumatic stress disorder, and attenuated tumor development. No differences from controls were found in behavior tests, immune parameters, or survival after tumor cell inoculation.

• Lay summary

• This article explores biological and behavioral consequences of social isolation in a mice model. Our results show that social isolation leads to changes in the Hypothalamic-hypophyseal-adrenal axis, which in turn alter the response to stress. Additionally, social isolation was shown to impact tumor progression.

摘要

这项研究的目的是调查长期隔离在动物模型中的行为，免疫和神经方面的影响。在社交隔离或标准条件下饲养雄性C3H / eB小鼠6周。在第10周，将每组进一步分为3组。（A）通过握力，热板，楼梯和高架迷宫测试评估身体的力量和行为。测量了自然杀伤细胞活性和淋巴细胞增殖。（B）一半动物在3次提醒下遭受电击，并在每次提醒下评估冻结时间。16周后评估可的松水平。（C）给小鼠注射38 C-13然后观察B淋巴瘤细胞的大小和存活率。进行力量评估后，社交隔离小鼠的体重和抓地力明显降低。两组的行为测试结果相似。对压力调节的反应模式显着不同，社会隔离的小鼠在每次连续提醒时都表现出冰冻倾向，而对照小鼠则表现出下降。被社会隔离的小鼠的肿瘤生长明显减弱，与对照组小鼠的存活率无显着差异。免疫学参数之间没有显着的组间差异。总之，社会孤立是慢性压力的模型。它与压力调节反应的显着变化相关，类似于创伤后应激障碍的症状，并减弱了肿瘤的发展。在行为测试，免疫参数或肿瘤细胞接种后的存活率方面，与对照组没有发现差异。

• 放置摘要

• 本文探讨了在小鼠模型中社交孤立的生物学和行为后果。我们的结果表明，社会隔离导致下丘脑-下垂-肾上腺轴的变化，进而改变对压力的反应。此外，社会隔离被证明会影响肿瘤的进展。