MODELING OF SIDS IN NEONATAL SWINE

新生仔猪作为婴幼儿猝死综合征动物模型的研究 (小岛屿发展中国家)，我们将调查(使用急性和慢性准备)： 1)迷走神经和迷走神经支配心脏的生后差异 节后交感运动神经元，2)心脏的作用 心律失常与选择性内脏传入刺激的作用 小岛屿发展中国家的病因，3)不同组合的影响 心脏的自主神经丧失对生存的影响。此外，慢性 无论是假手术还是去神经手术的动物，都将在 不同的条件，包括进料、温度等应力 变化或缺氧。这些去神经研究将使 确定出生后神经支配的重要性。结果是 实验诱导的交感神经和/或迷走神经偏侧 优势将验证平衡神经支配的重要性 心。在急性准备中，我们还将检查 去神经作用：1)室颤阈值和2) 对刺激内脏传入的反应，例如心肺， J受体和化学感受器。最后，检查出生后成熟度。 心脏的自主调节，因此，在最伟大的时代 对心律失常的易感性，我们将在 腹外侧核歧义以确定：1)它们的变化 活动模式随年龄的变化，2)他们对传入输入的反应。和 3)他们的诱发反应是否与年龄有关。这些实验 还将提供有关心脏的作用所需的信息 小儿麻痹症的心律失常，以及新生猪的适宜性 作为这种疾病的动物模型。慢性动物将会是 在无菌操作条件下制备；血管入口将 用于血液采样和血压测量的植入物，而细丝 电极将被插入隔膜，用于监测 呼吸功能；心电图用针状电极记录。 急性实验将在萨凡麻醉下进行。这个 上述慢性和急性实验应能提供急需的 关于改变自主监管的重要性的信息 小岛屿发展中国家病因学的核心。

Using neonatal swine as our animal model of sudden infant death syndrome (SIDS), we will investigate (using both acute and chronic preparations): 1) postnatal differences in innervation of the heart by vagal and postganglionic sympathetic motoneurons, 2) the role of cardiac arrhythmias and the effects of selected visceral afferent stimulation in the etiology of SIDS, 3) the effects of different combinations of autonomic denervation of the heart on survival. In addition, chronic animals, either sham operated or denervated, will be studied under different conditions including such stresses as feeding, temperature changes or hypoxia. These denervation studies will allow the determination of the importance of innervation postnatally. The results of the experimentally induced laterality of sympathetic and/or vagal dominance will verify the importance of balanced innervation of the heart. In the acute preparation we will also examine the effects of denervation on: 1) the ventricular fibrillation threshold and 2) responses to stimulation of visceral afferents, e.g., cardiopulmonary, J-receptor and chemoreceptor. Finally, to examine postnatal maturation of autonomic regulation of the heart and, therefore, of times of greatest susceptibility to arrhythmias, we will obtain motoneurons in the ventrolateral nucleus ambiguous in order to determine: 1) their changing pattern of activity with age, 2) their responses to afferent inputs. and 3) whether their evoked responses are age-related. These experiments will also supply the needed information concerning the role of cardiac arrhythmias in SIDS as well as document the suitability of neonatal swine as an animal model for this disease. The chronic animals will be prepared under sterile operating conditions; vascular access ports will be implanted for blood sampling and pressure measurements while fine wire electrodes will be inserted into the diaphragm for monitoring of respiratory function; the EKG will be recorded from needle electrodes. Acute experiments will be performed under Saffan anesthesia. The aforementioned chronic and acute experiments should supply much needed information regarding the importance of changing autonomic regulation of the heart in the etiology of SIDS.