Photoperiod, Melatonin, and Sickness Behaviors

光周期、褪黑激素和疾病行为

• 批准号: 6943927
• 负责人: Randy J. Nelson
• 金额: $ 29.03万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-08-15 至 2007-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6943927
• 关键词: T lymphocyte; animal population study; anorexia; behavior test; behavioral /social science research tag; biological signal transduction; cell migration; cellular immunity; ethology; fertility; hamsters; hyperthermia; interleukin 1; melatonin; photostimulus; prostaglandin endoperoxide synthase; psychoneuroimmunology; stress

DESCRIPTION (provided by applicant): Infection results in the rapid onset of adaptive sickness responses, termed the acute phase response, and includes physiological changes such as fever, increased sleep, as well as behavioral changes such as reduced food and water intake, activity, exploration, and social interactions. These so-called "sickness behaviors" are organized, adaptive strategies that are often crucial for host survival, rather than nonspecific manifestations of illness. Mounting an immune response is energetically costly. For many animals living in non-tropical habitats, a predictable annual energy shortage occurs each winter. During the short days of winter, low food availability often coincides with high thermoregulatory demands in low temperatures. Specific adaptations to conserve energy, such as inhibiting reproduction and growth, have evolved among animals to enhance winter survival. Immune function and responses to infection are also constrained by available energy, and may be altered by changes in the external environment. The proposed experiments are designed to investigate whether sickness behaviors or immune cell trafficking may be influenced by available energy or other factors signaled by melatonin. The specific aims of the proposed research are: (1) To determine if early immune activation evokes long-term reproductive costs. (2) To determine if short-day alterations in sickness responses are mediated by melatonin. (3) To discover if melatonin acts directly on lymphocytes to alter cytokine production. (4) To determine if short days and melatonin reduce the duration of fever by affecting brain levels of cyclooxygenase (COX) and interleukin(IL)-1a. (5) To determine if photoperiod and melatonin affect immune cell populations and leukocyte trafficking. (6) To determine if photoperiod influences the extent to which stress compromises immune function. Taken together, these studies may reveal novel therapeutic uses of melatonin on fever and anorexia.

描述（由申请人提供）：感染导致适应性疾病反应快速发作，称为急性期反应，包括发烧、睡眠增加等生理变化，以及食物和水摄入、活动、探索和社交互动减少等行为变化。这些所谓的“疾病行为”是有组织的、适应性的策略，通常对宿主的生存至关重要，而不是疾病的非特异性表现。发起免疫反应需要耗费大量精力。对于许多生活在非热带栖息地的动物来说，每年冬天都会出现可预测的年度能源短缺。在短暂的冬季，食物供应量低往往与低温下的高体温调节需求同时发生。动物们已经进化出了节省能量的特定适应能力，例如抑制繁殖和生长，以提高冬季生存能力。免疫功能和对感染的反应也受到可用能量的限制，并且可能会因外部环境的变化而改变。拟议的实验旨在研究疾病行为或免疫细胞运输是否可能受到可用能量或褪黑激素信号的其他因素的影响。拟议研究的具体目标是：（1）确定早期免疫激活是否会引起长期生殖成本。 (2) 确定疾病反应的短日照变化是否是由褪黑激素介导的。 (3) 探索褪黑激素是否直接作用于淋巴细胞以改变细胞因子的产生。 (4) 确定短日照和褪黑激素是否通过影响脑内环氧合酶 (COX) 和白细胞介素 (IL)-1a 的水平来缩短发烧持续时间。 (5) 确定光周期和褪黑激素是否影响免疫细胞群和白细胞运输。 (6) 确定光周期是否影响应激损害免疫功能的程度。总而言之，这些研究可能揭示褪黑激素治疗发烧和厌食症的新用途。