DISSERTATION RESEARCH: Study of sickness behavior and its costs in relation to immunosenescence

Carol M Vleck & Maria G. PalaciosIOS-0808555，疾病行为及其与免疫衰老相关的成本研究。免疫功能随着年龄的增长而下降，或称免疫衰老，是动物中普遍存在的现象。该项目旨在调查自由生活鸟类的免疫功能哪些方面受年龄影响最大，以及对个体的影响。树燕是模型系统，因为足够数量的已知年龄的个体可以重复采样，它们的繁殖成功可以很容易地监测。研究人员已经证明，树燕的免疫衰老模式与人类相似。在燕子照顾自己的孩子时，将进行一项实地实验，以评估这种衰老模式的后果。研究人员将用一种非感染性细菌成分来挑战不同年龄的鸟类，从而模拟一种致病性侮辱，这种细菌成分会引起疾病反应，但不会引起实际疾病。父母的行为，以喂养小鸡的形式，将通过视频记录和血液样本进行监测，在挑战之前和之后，将允许评估激素和免疫反应。将测量雏鸟的生长速度和羽化成功率。研究人员将测试一个假设，即年龄较大的免疫衰老个体比年轻人支付更高的防御病原体的成本，并预测年龄较大的个体在行为和生理上都会表现出更极端的疾病反应，这将导致与年轻人相比，生殖成功率和/或存活率降低。该项目将包括在实地和实验室对本科生进行培训。研究疾病反应及其对生殖行为和生存的影响对疾病生态学和濒危物种保护具有重要意义。此外，这项研究将引起生理学家、老年学家和进化生态学家的普遍兴趣，并随着人口老龄化对公众的重要性日益增加。

Carol M Vleck & Maria G. PalaciosIOS-0808555, Study of sickness behavior and its costs in relation to immunosenescence.The decline of immune function with age, or immunosenescence, is a pervasive phenomenon in animals. This project is designed to investigate what aspects of immune function are most affected by age in a free-living bird population and what are the consequences for individuals. Tree swallows are the model system because an adequate number of known-aged individuals can be repeatedly sampled and their reproductive success can be easily monitored. The researchers have already shown that the pattern of immunosenescence in tree swallows resembles that of humans. A field experiment will be carried out while swallows are caring for their young to assess the consequences of this aging pattern. Researchers will simulate a pathogenic insult by challenging birds of disparate ages with a non-infectious bacterial component, which elicits sickness responses without causing actual disease. Parental behavior, in the form of chick feeding, will be monitored using video recording and blood samples taken before and after the challenge will allow assessment of hormonal and immunological responses. Chick growth rates and fledging success will be measured. Researchers will test the hypothesis that older, immunosenescent individuals pay higher costs of defense against pathogens than younger ones with the prediction that older individuals will show more extreme sickness responses, both behavioral and physiological, that will result in reduced reproductive success and/or survival compared to young individuals. The project will include training of undergraduate students in the field and in the lab. This research on sickness responses and their effects on reproductive behavior and survival has implications for disease ecology and conservation of threatened/endangered species. In addition, this research will be of general interest to physiologists, gerontologists, and evolutionary ecologists, and of increasing importance to the general public as our population ages.