DEVELOPMENT OF AUTONOMIC AND BEHAVIORAL THERMOREGULATION

自主和行为体温调节的发展

• 批准号: 2250040
• 负责人: Mark Samuel Blumberg
• 金额: $ 9.88万
• 依托单位: UNIVERSITY OF IOWA
• 依托单位国家: 美国
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-05-01 至 1999-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2250040
• 关键词: adrenal medulla; autonomic nervous system; body temperature regulation; brown fat; catecholamines; chromaffin cells; developmental neurobiology; hypoxia; innervation; laboratory rat; newborn animals; sympathetic nervous system

Mammalian thermoregulation is typically divided into two components, autonomic and behavioral. The characteristics of both components are well known in adults, but their coordination in adults makes it difficult to discern the ways in which animals integrate and coordinate responses. Developmental approaches are useful in this regard because altricial newborn mammals possess immature responses that become mature and coordinated during relatively brief developmental transitions. One such transition, recently identified in this laboratory, involves a diminution in thermoregulatory responsiveness between the ages of two and eight days. This transition is important because its occurrence suggests mechanisms of thermoregulatory activation that are different from those currently suspected. Specifically, it is believed that heat production in newborn rats is activated solely by direct neural activation of brown adipose tissue (BAT). It is hypothesized here, however, that circulating catecholamines, released from chromaffin tissue in the adrenal medulla and/or the organ of Zuckerkandl, contribute to BAT activation. It is further hypothesized that the transition from robust BAT activation at birth to muted BAT activation within one week results from developing sympathetic innervation as well as involution of the organ of Zuckerkandl. These hypotheses will be tested using pharmacological and surgical manipulations of these organs and systems during development. In parallel with these physiological investigations, a novel head-turning paradigm involving radiant heat reinforcement will be used to investigate the development of thermal preference over the same postpartum period. In addition, because a synthesis of these two approaches is one primary goal of this project, interactions between autonomic and behavioral responses will be investigated as pups develop. It is hypothesized that coordination of physiological and behavioral responses will emerge as both thermoregulatory components mature during the first week postpartum. Finally, these interdisciplinary studies of week-old rats may provide valuable information regarding the comparable developmental stage of two to four months in human infants, at which time infants are most at risk for Sudden Infant Death Syndrome.

哺乳动物的体温调节通常分为两个部分， 自主和行为。两种成分的特性都很好 在成人中已知，但它们在成人中的协调性使得很难 辨别动物整合和协调反应的方式。 发育方法在这方面很有用，因为晚熟 新生哺乳动物具有不成熟的反应，但会变得成熟并 在相对短暂的发展转型期间进行协调。这样的一位 该实验室最近发现的转变涉及减少 两到八天龄之间的体温调节反应能力。 这种转变很重要，因为它的发生表明了 与目前不同的体温调节激活 怀疑。具体来说，据信新生儿产热 大鼠仅通过棕色脂肪的直接神经激活来激活 组织（最佳可行技术）。然而，这里假设循环 儿茶酚胺，从肾上腺髓质的嗜铬组织中释放 和/或 Zuckerkandl 器官，有助于 BAT 激活。这是 进一步假设从稳健的 BAT 激活的转变 发育过程中一周内 BAT 激活减弱的结果 交感神经支配以及 Zuckerkandl 器官的复旧。 这些假设将通过药理学和外科手术进行检验 在发育过程中对这些器官和系统的操纵。并联 通过这些生理学研究，一种新颖的令人头晕的范式 涉及辐射热强化将用于研究 在同一产后时期热偏好的发展。在 此外，因为综合这两种方法是一个主要目标 在这个项目中，自主反应和行为反应之间的相互作用 随着幼崽的发育，将进行调查。假设协调 生理和行为反应都会出现 体温调节成分在产后第一周成熟。 最后，这些针对周龄大鼠的跨学科研究可能提供 关于两个人可比发展阶段的宝贵信息 人类婴儿至四个月，此时婴儿面临的风险最大 对于婴儿猝死综合症。