Homeostasis and behavioral state organization in infants

描述(由申请者提供)：独立科学家奖将支持由美国国立卫生研究院资助的对幼年啮齿动物基本生物行为过程的正在进行的研究，特别是关于睡眠的机制和功能。在过去的5年里，PI将越来越多的资源用于解决关于睡眠的核心问题之一：为什么婴儿比成年人睡得更多？尽管这个问题对人类健康有明显的影响，但绝大多数的睡眠研究仍然集中在成年人身上。在PI实验室最新进展的基础上，包括开发出记录未麻醉幼鼠在睡眠和清醒之间循环时的神经活动的技术，目前的提议有两个主要目标。第一个目标是研究超常和昼夜睡眠-觉醒节律形成的感觉和神经机制。一个相关的目的是描述在睡眠和觉醒的统计分布中产生戏剧性的数量和质量发展变化的机制，现在已经在大鼠和小鼠出生后的前三周证明了这些变化。PI处于一个独特的位置，能够检查产生这些基本睡眠-觉醒节奏的神经机制的发展，并将使用各种实验方法来做到这一点。例如，将研究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。这项提议的第二个目的是利用非传统物种来解决与睡眠和觉醒发展有关的机械性和功能性问题。例如，作为早熟物种，棉鼠(Sigmodon Hispidus)可能有助于我们解释为什么出生在相对成熟状态的婴儿一生中睡眠较少；而作为一种昼夜物种，尼罗河鼠(Arvicanthis Niloticus)可能有助于我们识别神经回路中的关键发育变化，这些变化是人类昼夜节律模式的基础。这项建议中采用的发展框架避免将婴儿睡眠与成人标准进行比较，而是试图了解随着发育时间的变化过程。该项目的一个长期目标是进一步为我们理解睡眠发育的机制奠定基础，以便能够在以后的生活中识别潜在的睡眠失调机制。

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.