Homeostasis and behavioral state organization in infants

描述（由申请人提供）：独立科学家奖将支持正在进行的NIH资助的婴儿啮齿动物基本生物行为过程的研究，特别是关于睡眠的机制和功能。在过去的5年里，PI已经将越来越多的资源用于有关睡眠的核心问题之一：为什么婴儿比成人睡得更多？尽管这个问题对人类健康有明显的影响，但绝大多数睡眠研究仍然集中在成年人身上。基于PI实验室的最新进展，包括开发记录未麻醉幼鼠在睡眠和觉醒之间循环时神经活动的技术，目前的提案有两个主要目标。第一个目的是研究超昼夜和昼夜睡眠-觉醒节律发展的感觉和神经机制。一个相关的目的是描述机制，产生戏剧性的数量和质量的发展变化的统计分布的睡眠和觉醒发作，现在已经证明了在大鼠和小鼠出生后的前三个星期。PI处于能够检查产生这些基本睡眠-觉醒节律的神经机制的发展的独特位置，并且将使用各种实验方法来这样做。例如，视觉系统的发育贡献及其与视交叉上核和视顶盖的解剖和功能联系将被检查。这项提议的第二个目的是利用非传统物种来解决有关睡眠和觉醒发展的机制和功能问题。例如，作为早熟物种，棉鼠（Sigmodon hispidus）可以帮助我们解释为什么出生在相对成熟状态下的婴儿一生中睡眠较少;作为昼夜物种，尼罗河草鼠（Arvicanthis niloticus）可以帮助我们确定人类昼夜节律模式背后的神经回路的关键发育变化。本建议中采用的发展框架避免了将婴儿睡眠与成人标准进行比较，而是试图了解随着发展时间的变化过程。该项目的一个长期目标是进一步奠定我们对睡眠发展机制的理解的基础，以便能够识别生命后期睡眠失调的潜在机制。

DESCRIPTION (provided by applicant): An Independent Scientist Award would support on-going NIH-funded investigations of basic biobehavioral processes in infant rodents, especially concerning the mechanisms and function of sleep. Over the past 5 years, the PI has directed increasing resources toward one of the central questions concerning sleep: Why do infants sleep more than adults? Despite the obvious implications of this question for human health, the vast majority of sleep research continues to focus on adults. Building on recent progress in the PI's laboratory, including the development of techniques for recording neural activity in unanesthetized infant rats as they cycle between sleep and wakefulness, the current proposal has two primary aims. The first aim is to examine the sensory and neural mechanisms that underlie development of ultradian and circadian sleep- wake rhythms. A related aim is to describe the mechanisms that produce the dramatic quantitative and qualitative developmental changes in the statistical distributions of sleep and wake bouts that have now been demonstrated in rats and mice over the first three postnatal weeks. The PI is in the unique position of being able to examine the development of the neural mechanisms that generate these fundamental sleep-wake rhythms, and will do so using a variety of experimental approaches. For example, the developmental contributions of the visual system and its anatomical and functional connections with the suprachiasmatic nucleus and optic tectum will be examined. The second aim of this proposal is to employ non-traditional species to address mechanistic and functional questions concerning the development of sleep and wakefulness. For example, as a precocial species, cotton rats (Sigmodon hispidus) may help us to explain why infants born in a state of relative maturity exhibit less sleep throughout life; and as a diurnal species, Nile grass rats (Arvicanthis niloticus) may help us to identify the critical developmental changes in neural circuitry that underlie the diurnal circadian pattern of humans. The developmental framework adopted in this proposal avoids comparison of infant sleep against an adult standard but rather seeks to understand the processes of change over developmental time. One long-term goal of this project, which renewal of this award will make possible, is to further lay a foundation for our understanding of the mechanisms of sleep development so as to enable identification of the mechanisms underlying sleep dysregulation later in life.