DEVELOPMENT OF AUTONOMIC AND BEHAVIORAL THERMOREGULATION

哺乳动物体温调节通常分为两个部分， 自主的和行为的。这两个组件的特性都很好 已知在成人中，但它们在成人中的协调使其很难 辨别动物整合和协调反应的方式。 发展的方法在这方面是有用的，因为 新生的哺乳动物具有不成熟的反应，这些反应会成熟并 在相对较短的发展过渡期间进行协调。这样的一个 转变，最近在这个实验室中被发现，包括减少 在两到八天的婴儿的体温调节反应能力上。 这种转变很重要，因为它的发生暗示了 与目前不同的体温调节激活 有嫌疑。具体地说，人们认为新生儿的产热 大鼠只通过棕色脂肪的直接神经激活而激活 组织(蝙蝠)。然而，这里假设的是，循环 肾上腺髓质嗜铬组织释放的儿茶酚胺 和/或Zuckerkandl的器官，有助于BAT的激活。它是 进一步假设，从强健的BAT激活到 出生一周内静音蝙蝠激活导致发育 交感神经支配以及Zuckerkandl器官的退化。 这些假说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。并行的 通过这些生理学研究，一种新的掉头范式 涉及辐射热加固将被用来调查 产后同一时期的热偏爱的发展。在……里面 此外，因为综合这两种方法是一个主要目标 在这个项目中，自主神经和行为反应之间的相互作用 将在幼崽发育过程中进行调查。据推测，协调 的生理和行为反应会同时出现 体温调节成分在产后第一周成熟。 最后，这些对一周龄大鼠的跨学科研究可能会提供 关于两个可比较的发育阶段的有价值的信息 到四个月的人类婴儿，在这个时候婴儿面临的风险最大 治疗婴儿猝死综合症。

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.