Photoperiod, Melatonin, and Sickness Behaviors

光周期、褪黑激素和疾病行为

• 批准号: 6790677
• 负责人: Randy J. Nelson
• 金额: $ 29.08万
• 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/6790677
• 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）：感染会导致自适应疾病反应的快速发作，称为急性相反应，包括生理变化，例如发烧，睡眠增加以及行为变化，例如食物和水的摄入量，活动，探索和社交互动。这些所谓的“疾病行为”是组织的，适应性策略通常对于宿主生存至关重要，而不是疾病的非特异性表现。安装免疫反应在能量上是昂贵的。对于许多生活在非热带栖息地中的动物，每年冬天都会发生可预测的年能量短缺。在冬季的短时间内，低食物的可用性通常与低温下的热调节性需求相吻合。保护能量的特定适应性，例如抑制繁殖和生长，在动物之间发展以增强冬季的生存。免疫功能和对感染的反应也受到可用能量的限制，外部环境的变化可能会改变。提出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。拟议研究的具体目的是：（1）确定早期免疫激活是否唤起长期生殖成本。 （2）确定疾病反应的短期改变是否由褪黑激素介导。 （3）发现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）确定短天和褪黑激素是否通过影响大脑的环氧合酶（COX）和白介素（IL）-1a来减少发烧的持续时间。 （5）确定光周期和褪黑激素是否影响免疫细胞群体和白细胞运输。 （6）确定光周期是否影响应力损害免疫功能的程度。综上所述，这些研究可能揭示了褪黑激素对发烧和厌食症的新型治疗用途。