Temporal Patterns in Sleep Mechanisms of Learning

描述(申请人提供)：睡眠是一种普遍的行为。一种功能假说提出，在睡眠期间，前一天经历的知觉或程序性活动被概括，一些记忆得到巩固，另一些记忆被抹去。这一假说得到了斑雀前脑核RA中单个神经元的观察支持，这些神经元表现出神经元重放，在歌唱时以及后来在未受干扰的睡眠中和对歌曲回放的反应中，类似的爆发活动模式。然而，由于缺乏分析神经元活动的时间模式的程序，直接验证这一假说受到阻碍，特别是在缺乏时间参考的睡眠期间。这项拟议的研究将开发必要的统计建模和神经生理学实验，以直接检查睡眠的功能模型。在第一个实验中，RA的睡眠重放假说将得到严格的统计检验。将开发模式过滤方法来评估匹配，不仅用于单个脉冲，而且还用于序列脉冲。将描述重放图案的统计意义，并且将导出在单个小区级别的重放现象的更完整的描述。在第二个实验中，将检验睡眠重放发生在RA传入核团中的假设。记录HVC传入核内不同投射类型神经元的活动。将开发基于信息和基于度量的时间对齐技术，以适应这些神经元与RA神经元相比时间分辨率较低的情况。内部噪声和上下文相关的时间精度将被考虑以最大限度地对准尖峰。在第三个实验中，将检验来自IMAN的传入输入改变夜间周期中RA活动的特定假设。一种名为自适应模式过滤的新统计模型将被开发出来，以评估在睡眠期间何时首次识别出注定要在第二天的歌唱行为中表现出来的突发模式。记忆巩固假说将通过评估以下预测来检验：在IMAN损伤后，睡眠时间后RA猝发模式应该较少或没有变化。第四个实验将直接从RA记录幼鸟学习唱歌的过程。在这种情况下，白天和睡眠期间的行为(唱歌)和神经生理活动可能表现出高度的变异性，这将需要统计建模。行为的变化将用熵和其他统计指标进行评估。RA突发模式在睡眠中的变化方向会预测第二天的唱歌行为，这一假说将直接得到检验。

DESCRIPTION (provided by applicant): Sleep is a universal behavior. One functional hypothesis proposes that during sleep perceptual or procedural activity experienced during the prior day is recapitulated, with some memories consolidated and others erased. This hypothesis is supported by observations of individual neurons in the zebra finch forebrain nucleus RA that exhibit neuronal replay, similar patterns of bursting activity during singing and later during undisturbed sleep and in response to song playback. Directly testing the hypothesis, however, is hampered by the lack of procedures to analyze temporal patterns of neuronal activity, especially during sleep in the absence of a time-reference. The proposed research will develop essential statistical modeling and neurophysiological experiments to directly examine functional models of sleep. In the first experiment, the hypothesis of sleep replay in RA will be rigorously statistically tested. Patten filtering methods will be developed to assess matching not only for individual bursts but also for trains of bursts. The statistical significance of replay patterns will be described and a more complete description of the replay phenomenon at the single cell level will be derived. In the second experiment, the hypothesis that sleep replay occurs in nuclei afferent to RA will be tested. The activities of different projection classes of neurons in the afferent nucleus HVc will be recorded. Information-based and metric-based alignment techniques for temporal alignment will be developed to accommodate the lower temporal resolution of these neurons, as compared to RA neurons. The internal noise, and context-dependent temporal precision will be considered to maximize spike alignment. In the third experiment, the specific hypothesis that afferent input from IMAN modifies RA activity on a nocturnal cycle will be tested. A new statistical model, adaptive pattern filtering, will be developed to assess when during sleep are burst patterns first recognized that are destined to be expressed in singing behavior the following day. The memory consolidation hypothesis will be tested by assessing the prediction that after IMAN lesions there should be fewer or no changes in RA burst patterns following periods of sleep. The fourth experiment will record directly from RA in juvenile birds learning to sing. In this case, behavior (singing) and neurophysiological activity during the day as well as during sleep is likely to exhibit high variability which will require statistical modeling. Changes in behavior will be assessed with entropy and other statistical measures. The hypothesis that RA burst patterns change during sleep in a direction that predicts singing behavior the following day will be directly tested.