AUTONOMIC NERVOUS SYSTEM FUNCTIONING IN THE HUMAN FETUS

人类胎儿自主神经系统的功能

• 批准号: 2655141
• 负责人: LYNN J GROOME
• 金额: $ 10.39万
• 依托单位: UNIVERSITY OF SOUTH ALABAMA
• 依托单位国家: 美国
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-02-01 至 2000-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2655141
• 关键词: auditory stimulus; central nervous system; developmental neurobiology; electrocardiography; embryo /fetus; heart rate; human subject; infant human (0-1 year); mammalian embryology; newborn human (0-6 weeks); parasympathetic nervous system; sympathetic nervous system

A number of developmental disorders in children, including learning disabilities, can be traced to deficits in attention and abnormalities in autonomic nervous system (ANS) functioning. A vagally-mediated decrease in heart rate is used as a marker of attention in infants, and an association between prestimulus respiratory sinus arrhythmia (RSA) and the magnitude of the heart rate deceleration has been demonstrated. Evaluation of ANS functioning and information processing capabilities are particularly well- suited for assessing central nervous system (CNS) status in utero: the ANS can be examined in human fetuses noninvasively using spectral decomposition techniques, and human fetuses are capable of displaying a heart rate deceleratory response to certain acoustic stimuli. After identifying acoustic parameters which consistently elicit a heart rate deceleration in normal human term fetuses, we will examine the relationship between prestimulus RSA and the magnitude of the cardiac deceleratory response and determine if there is a decrease in respiratory frequency and heart rate variability (HRV) concomitant with the heart rate deceleration. Furthermore, we will determine if fetuses categorized as sympathetic-dominant exhibit a different type of cardiac response to low- intensity acoustic stimuli than fetuses categorized as parasympathetic- dominant and whether these characteristics are stable over time. Special emphasis will be placed on identifying parameters which are capable of distinguishing growth-restricted fetuses and fetuses with CNS structural anomalies from normal fetuses. An important aspect of the proposed study plan is that subjects examined as fetuses will be examined again as neonates and will be followed prospectively to two years of age. The fetal electrocardiogram will be captured noninvasively using standard cardiac electrodes positioned on the mother's abdomen. Adaptive signal processing methodology will be used to extract fetal R-waves from the raw data. Sympathetic-parasympathetic balance will be evaluated by applying spectral decomposition techniques to the analysis of fetal and neonatal HRV data. The heart rate response to low-intensity acoustic stimuli will be related to ANS functioning in both fetuses and neonates. We believe that differences in intrinsic ANS activity and cardiac responsivity may ultimately help to identify the fetus at-risk for neurobehavioral abnormalities and hence facilitate the implementation of appropriate intervention protocols early in the course of development.

儿童的一些发育障碍，包括学习障碍 残疾，可以追溯到缺陷的注意力和异常， 自主神经系统（ANS）功能。迷走神经介导的 心率被用作婴儿注意力的标志， 刺激前呼吸性窦性心律失常（RSA）与 心率减慢的原因已经得到证实。ANS的评价 功能和信息处理能力特别好- 适用于评估子宫内中枢神经系统（CNS）状态：ANS 可以在人类胎儿中进行检查， 分解技术，和人类胎儿能够显示一个 对某些声音刺激的心率减速反应。后 识别一致地引出心率的声学参数 在正常人类足月胎儿中，我们将检查 RSA刺激前与心脏搏动幅度的关系 减速反应，并确定是否有呼吸减少 频率和心率变异性（HRV）伴随心率 减速。此外，我们将确定是否将胎儿归类为 交感神经支配型对低- 强度声刺激比胎儿归类为副交感神经- 这些特征是否随时间而稳定。特别 重点将放在确定能够 区分生长受限胎儿和CNS结构性胎儿 正常胎儿的异常拟议研究的一个重要方面是 计划是，作为胎儿检查的受试者将在 新生儿，并将前瞻性随访至2岁。 的 胎儿心电图将使用标准的非侵入性采集 心脏电极放置在母亲的腹部。自适应信号 将使用处理方法从原始数据中提取胎儿R波 数据交感神经-副交感神经平衡将通过应用 光谱分解技术用于胎儿和新生儿的分析 HRV数据。对低强度声刺激的心率反应将 与胎儿和新生儿的ANS功能有关。我们认为 内在ANS活动和心脏反应性的差异可能 最终有助于识别胎儿的神经行为风险， 异常，从而促进实施适当的 在发展过程的早期干预方案。