CONTROL OF THE RESPIRATORY SYSTEM BY THE HYPOTHALAMUS

这项建议中的研究目的是调查 下丘脑参与呼吸控制 系统。多项研究表明， 下丘脑参与调节某些心血管疾病 条件反射。例如，心血管反应 压力感受器和外周化学感受器的刺激 已知会被下丘脑中的位置改变。即使 这些受体的激活也会影响呼吸，几乎没有 研究检测了下丘脑在调节 呼吸反应。因此，研究的具体目的是 在这项提案中描述的是调查 下丘脑部位在调节呼吸反射和 测定下丘脑利用的神经递质 调节呼吸的部位。呼吸反射是 被研究的是那些通过刺激肺伸展而诱发的 受体(Hering-Breuer反射)；2)外周化学受体；3) 中枢化学感受器和4)动脉压力感受器。三套 的实验将在麻醉的猫身上进行。首先， 不同脑区神经元“兴奋性状态”的变化 下丘脑对呼吸反射的部位将是 下定决心。兴奋性状态将由化学物质或 电刺激，并将通过电解性损伤降低 或通过对下丘脑部位进行局部降温。在第二组 对呼吸反射的影响的实验研究 向脑内微量注射神经递质安慰剂 将对下丘脑进行评估。最后，将确定是否 上面列出的呼吸刺激会改变放电频率 下丘脑神经元。从这些信息中获得的信息 实验应该增加对神经的整体理解。 控制呼吸。这些发现可能会提供对 神经异常导致了一些中枢神经系统 呼吸系统疾病。

The purpose of the research in this proposal is to investigate hypothalamic involvement in the control of the respiratory system. Several studies have demonstrated that areas in the hypothalamus are involved in modulating some cardiovascular reflexes. For example, the cardiovascular responses to stimulation of baroreceptors and peripheral chemoreceptors are known to be modified by sites in the hypothalamus. Even though activation of these receptors also affects ventilation, almost no research has examined a role of the hypothalamus in regulating respiratory responses. Therefore, the specific aims of the studies described in this proposal are to investigate a potential role of hypothalamic sites in regulating respiratory reflexes and to determine the neurotransmitters utilized by the hypothalamic sites which modulate breathing. The respiratory reflexes to be studied are those evoked by stimulation of 1) pulmonary stretch receptors (Hering-Breuer reflex); 2) peripheral chemoreceptors; 3) central chemoreceptors and 4) arterial baroreceptors. Three sets of experiments will be performed in anesthetized cats. First, the effects of changing the "excitability state" of neurons in selected hypothalamic sites upon the respiratory reflexes will be determined. The excitability state will be raised by chemical or electrical stimulation and will be lowered by electrolytic lesions or by focal cooling of hypothalamic sites. In a second set of experiments the effects upon the respiratory reflexes of microinjecting neurotransmitter antogonists into the hypothalamus will be evaluated. Finally, it will be determined if the respiratory stimuli listed above alter the discharge frequency of hypothalamic neurons. The information gained from these experiments should add to the overall understanding of the neural control of respiration. These findings may offer insights into the neurological abnormalities responsible for some central respiratory disorders.