CARDIORESPIRATORY PATTERNS DURING SLEEP AND SIDS RISK

我们的目的是检验这样一种假设，即在突然发生的婴儿中失败 死亡综合征(SIDS)是由睡眠障碍引起的 延髓腹面(VMS)，或在髓上投射到 VMS的心脏和呼吸区，因此改变了能力 来调节血压的变化，从而影响觉醒和 呼吸模式。小岛屿发展中国家受害者表现出“失败”的迹象 唤醒，“减少心脏和呼吸间期的变化 表明呼吸-心血管相互作用受损，以及 证据表明VMS上的毒扁豆碱结合减弱。 VMS内的功能障碍区域或向此表面的投射 会使婴儿在呼吸和心血管疾病期间处于危险之中 睡眠方面的挑战。地区性VMS地区在调解中的作用 将在睡眠唤醒期间检查呼吸和升压挑战 小猫四岁时的状态(L)评估“自发”活动 在VMS区域的睡眠唤醒状态期间，使用单细胞放电， 诱发电位和光学成像技术；2)评估区域 VMS对分级低氧、高碳酸血症、负荷性呼吸和 氰化物挑战，以及加压和降压操作；3)与 挑战上呼吸道和下呼吸道模式引起的VMS活动 隔膜活动，并对血压有影响；4)刺激 髓上区域，并检查其对VMS的综合影响 对地点和心肺活动的影响。一种相干成像光纤 探头和摄像头将放置在VMS上，以及可移动的 无菌手术中的一束微电极。刺激电极 将被放置在髓上区域，已经证明 投射到VMS，或显示明显的呼吸激活 挑战。横隔膜和喉部外展肌的肌电图样 扩张器(分别为环甲肌和环踝后肌)将 用于呼吸测量。反射光的图像发生变化 与神经活动有关，包括血管和细胞肿胀 变化，将被数字化，连同单细胞放电和广泛的 无干扰睡眠时附着微电极的频带活动 在各州，以及在各州的心肺挑战期间。时间 序列分析，使用频谱、相干和滞后相关 技术，将用于将总体和区域VMS活动联系起来 不同情况下对呼吸和心跳周期以及 血压变化。

The objective is to test the hypothesis that failure in the sudden infant death syndrome (SIDS) results from a dysfunction during sleep of the ventral medullary surface (VMS), or in supramedullary projections to cardiac and respiratory areas of the VMS, thus altering the capability of this area to mediate blood pressure changes which affect arousal and respiratory patterning. SIDS victims show signs suggestive of a "failure to arouse," diminished variation in cardiac and respiratory intervals indicative of impaired respiratory-cardiovascular interactions, and evidence indicating diminished muscarinic binding on the VMS. Dysfunctional areas within the VMS, or in projections to this surface area, would place infants at risk during respiratory and cardiovascular challenges in sleep. The role of regional VMS areas in mediating ventilatory and pressor challenges will be examined during sleep-waking states at four ages in kittens by l) assessing "spontaneous" activity during sleep-waking states in VMS regions, using single cell discharge, evoked potential, and optical imaging techniques; 2) evaluating regional VMS responses to graded hypoxic, hypercapnic, loaded breathing and cyanide challenges, and pressor and depressor manipulations; 3) relating VMS activity evoked by challenges to patterns of upper airway and diaphragmatic activity, and to blood pressure; 4) stimulating supramedullary regions, and examining the resultant influence on VMS sites and on cardiorespiratory activity. A coherent image fiber optic probe and camera will be placed on the VMS, together with a moveable bundle of microelectrodes under sterile surgery. Stimulation electrodes will be placed in supramedullary regions that have demonstrated projections to the VMS, or show pronounced activation to respiratory challenges. EMG patterning of the diaphragm and a laryngeal abductor and dilator (cricothyroid and posterior cricoarytenoid, respectively), will be used for respiratory measures. Images of reflected light changes associated with neural activity, including vascular and cell swelling changes, will be digitized, together with single cell discharge and wide- band activity from attached microelectrodes during undisturbed sleep states, and during cardiorespiratory challenges within states. Time series analysis, using spectral, coherence and lagged correlation techniques, will be used to relate overall and regional VMS activity changes across conditions to the respiratory and cardiac cycle and to blood pressure variation.