INFLUENCE OF THE VENTRAL MEDULLA ON REFLEX RESPONES TO STIMULATION

腹延髓对刺激反射反应的影响

• 批准号: 6581882
• 负责人: JAMES C LEITER
• 金额: $ 23.61万
• 依托单位: BOSTON CHILDREN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-04-01 至 2003-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6581882
• 关键词: brain stem; cardiovascular function; decerebration; developmental neurobiology; disease /disorder model; glutamate receptor; hypercapnia; hypoxia; muscarinic receptor; newborn animals; phrenic nerve; respiration regulatory center; respiratory reflex; sleep; stimulus /response; sudden infant death syndrome; swine; thyrotropin releasing hormone; trigeminal nerve; wakefulness

We propose that the sudden infant death syndrome (SIDS) results when an infant when a neuronal vulnerability is exposed to an exogenous stressor at a critical time in development. The arcuate nucleus in humans, and homologous structures in the piglet- the retrotrapezoid nucleus, parapyramidal neurons, caudal raphe and chemoreceptor regions along the rostral and caudal surface of the ventral medulla-are possible sites of neuronal vulnerability. The exogenous stressor may be stimulation of facial or upper airway receptors or compression of the chest. These exogenous stressors inhibit respiration and may promote cardiovascular instability, but normal protective responses arising from asphyxia (hypoxia and hypercapnia) oppose the effect of these stressors, increase breathing, stabilize blood pressure, promote arousal, which alleviates inhibitory influences on respiration and may lead to postural changes that relieve asphyxia. Disruption of the arcuate neurons or the piglet homologue diminishes or eliminates protective responses, permits the unfettered actions of stimuli inhibiting respiration and may make a fatal outcome more likely. Specific Aim 1: In the decerebrate piglet at different developmental ages, we will examine the effect of lesions in the piglet homologue of the arcuate nucleus on ventilatory and cardiovascular responses (phrenic nerve activity, heart rate and blood pressure) during stimulation of the trigeminal or superior laryngeal nerve or stimulation of a now intercostal nerve during hypercapnia or hypoxia. Specific Aim 2: In decerebrate piglets at the developmental age most susceptible to disruption of protective responses we will examine the role of muscarinic, ionotropic glutamate and thyrotropin releasing hormone receptors in brainstem regions homologous to the arcuate nucleus on ventilatory and cardiovascular responses as in Specific Aim 1. Specific Aim 3: We will examine the effect of chronic lesions in the homologue of the arcuate nucleus on ventilatory and cardiovascular responses during stimulation of the trigeminal, superior laryngeal and intercostal nerves in unanesthetized piglets during room air exposure, hypercapnia or hypoxia during wakefulness and sleep (NREM and REM).

我们建议当婴儿突然死亡综合征（SIDS）当 婴儿当神经元脆弱性暴露于外源应激源时 在开发的关键时刻。人类的弓形核，以及 小猪中的同源结构 - 逆转录核， 在 腹侧髓质的尾部和尾表面是可能的位点 神经元脆弱性。外源应激源可能是刺激 面部或上呼吸道受体或胸部压缩。这些 外源应激源抑制呼吸，可能促进心血管 不稳定，但窒息产生的正常保护反应 （缺氧和高碳酸盐）反对这些压力源的作用，增加 呼吸，稳定血压，促进唤醒，这可以减轻 抑制性影响呼吸，并可能导致姿势变化 缓解窒息。弧形神经元或小猪的破坏 同源物减少或消除保护性反应，允许 刺激抑制呼吸的不受约束的作用，可能导致致命 结果更有可能。 特定目标1：在不同发育年龄的杂交小猪中， 我们将检查病变在小猪同源物中的影响 在通气和心血管反应上的弓形核（纤维神经 活动，心率和血压） 三叉神经或上喉神经或现在的肋间刺激 在高碳酸盐或缺氧期间神经。 特定目标2：在发育年龄的杂交小猪中 容易受到保护性反应的破坏，我们将检查该角色 毒蕈碱，离子型谷氨酸和促甲状腺激素的释放激素 脑干区域的受体与弓形核的同源 通气和心血管反应如特定目标1。 特定目的3：我们将检查慢性病变在 弓形核的同源物在通气和心血管上 刺激三叉神经，上喉和 房间空气曝光期间，肋间神经在未经麻醉的小猪中， 在清醒和睡眠期间（NREM和REM）期间的高碳酸盐或缺氧。