NEUROPHYSIOLOGICAL STUDIES OF VOMITING

这项研究的长期目标是确定神经机制 这是一个潜在的严重问题， 运动、空间、辐射和妊娠病，癌症治疗 病人，艾滋病。目前的重点是研究神经 控制主要呼吸（横膈膜、肋间、腹部） 产生腹内压和胸内压变化的肌肉 负责呕吐。 增加对神经系统的了解 产生呕吐的电路，以及对 多种神经递质受体亚型，应该会导致改善 呕吐的药理学对策以及可能的其他 与泌尿系统相关的功能障碍 大多数实验将涉及使用“虚构呕吐”，这是 以膈神经和腹部运动的共同激活为特征 去大脑瘫痪猫的神经 下一个大脑的作用 （虚构）呕吐中的脑干区域将通过记录 它们的单细胞活动：（a）中线（中缝）神经元， 参与控制膈和肋间运动神经元和上 颈吸气固有脊髓神经元，（B）吻腹侧 呼吸组（VRG）的propriobulbar神经元，可能抑制 延髓脊髓吸气神经元和尾侧VRG呼气神经元，（c） 尾侧VRG呼气神经元可能投射到Onuf核， 对控制尿道外括约肌和肛门括约肌很重要， (d)最后区神经元被认为是 呕吐的化学感受器触发区 脑投射部位 干神经元将通过其轴突的逆向激活来确定。 为了预测在虚构过程中下行脑干驱动的模式， 呕吐时，将确定膜电位的变化 发生于膈神经、腹部和肋间运动神经元，包括 抑制性输入在运动神经元放电形成中的作用。 作为 腹部运动神经元细胞内记录的先决条件， 将确定单个腹部肌肉的活动， 呕吐和，作为比较，其他的驱逐行为（咳嗽， 打喷嚏）。 最后，将进行损伤实验以描绘 脑干和上颈区呼吸肌所必需的 在（虚构的）呕吐期间激活，以确定不重要的区域， 并获得有关存在和位置的信息， 解剖学上定义明确的“呕吐中心”。

The long-term goal of this research is to determine the neural mechanisms that produce vomiting, a potentially serious problem associated with motion, space, radiation and pregnancy sickness, treatment of cancer patients, and AIDS.. The present emphasis is to investigate the neural control of the major respiratory (diaphragm, intercostal, abdominal) muscles that generate the intra-abdominal and -thoracic pressure changes responsible for vomiting. Increased understanding of the neural circuitry that produces vomiting, together with a growing knowledge of multiple neurotransmitter receptor subtypes, should lead to improved pharmacological countermeasures for vomiting as well as possibly other respiratory-related dysfunctions. Most experiments will involve the use of "fictive vomiting", which is characterized by bursts of coactivation of phrenic and abdominal motor nerves in decerebrate, paralyzed cats. The role of the following brain stem regions in (fictive) vomiting will be investigated by recording their single cell activity: (a) midline (raphe) neurons that may participate in control of phrenic and intercostal motoneurons and upper cervical inspiratory propriospinal neurons, (b) rostral ventral respiratory group (VRG) propriobulbar neurons that may inhibit bulbospinal inspiratory neurons and caudal VRG expiratory neurons, (c) caudal VRG expiratory neurons that may project to the nucleus of Onuf and be important for control of external urethral and anal sphincters, and (d) area postrema neurons that are thought to serve as a central chemoreceptor trigger zone for vomiting. The projection sites of brain stem neurons will be determined by antidromic activation of their axons. To anticipate the pattern of descending brain stem drives during fictive vomiting, a determination will be made of membrane potential changes occurring in phrenic, abdominal and intercostal motoneurons, including the role of inhibitory inputs in shaping motoneuronal discharge. As a prerequisite to intracellular recording from abdominal motoneurons, the activity of individual abdominal muscles will be determined during vomiting and, for comparison, other expulsive behaviors (coughing, sneezing). Finally, lesion experiments will be performed to delineate brain stem and upper cervical areas necessary for respiratory muscle activation during (fictive) vomiting, to determine regions not essential, and obtain information concerning the existence and location of an anatomically well-defined "vomiting center".