NEURONAL BASIS FOR CARDIORESPIRATORY INTEGRATION

这一建议是我们理解CNS的继续努力 负责协调呼吸和血管运动的回路 资金外流。本研究的重点是交感神经的通路。 刺激颈动脉化学感受器引发的反射 (化学交感神经反射)。这项研究的总体目标是解开 这种反射的主要中枢神经系统继电器，并描述了一些 牵涉到发射器。我们的主要假设是，在麻醉下， 交感神经化学反射的球通路几乎是完整的。 与压力感受性反射分离，直到球脊髓水平 对两个输入进行代数求和的前运动神经元。 根据初步实验，我们还认为这些前置马达 神经元位于延髓头端腹外侧区和桥脑 延髓移行区(A5去甲肾上腺素能细胞)。我们也 假设交感神经化学反射是通过 前Botzinger区，延髓的一个小核负责 用于呼吸节律的产生。 这一网络将用神经生理学方法在 麻醉大鼠，应用一种新的神经组织学技术 (原癌基因产物c-fos的神经元表达)使 有源中枢神经网络的映射。 这些实验应该会显著地阐明中央电路 负责交感神经化学反射，这是一种动态平衡机制 调节动脉压和局部血液的基本重要性 流动。

This proposal is the continuation of our efforts to understand the CNS circuitry responsible for coordinating respiratory and vasomotor outflows. The present study focuses on the pathway of the sympathetic reflex triggered by stimulation of carotid chemoreceptors (chemosympathetic reflex). The general goal of the study is to unravel the main CNS relays of this reflex and to characterize some of the transmitters involved. Our main hypothesis is that, under anesthesia, the bulbar pathway of the sympathetic chemoreflex is almost completely separate from that of the baroreflex until the level of the bulbospinal premotor neurons where algebraic summation of the two inputs occurs. Based on preliminary experiments, we also believe that these premotor neurons are located in the rostral ventrolateral medulla and the ponto medullary transitional zone (A5 noradrenergic cells) . We also hypothesize that the sympathetic chemoreflex is mediated via the pre-Botzinger area, a small nucleus of the medulla oblongata responsible for the generation of the respiratory rhythm. This network will be investigated with neurophysiological methods in the anesthetized rat and with a newly introduced neurohistological technique (neuronal expression of the protooncogene product c-fos) which allows the mapping of active CNS networks. These experiments should significantly clarify the central circuitry responsible for the sympathetic chemoreflex, a homeostatic mechanism of fundamental importance in regulating arterial pressure and regional blood flows.