VESTIBULAR INFLUENCES ON THE SYMPATHETIC NERVOUS SYSTEM

相当多的证据表明，来自前庭系统的输入 直接和强大的影响交感神经流出，以及血液 压力 前庭神经的电刺激改变活动 由支配身体许多区域的交感神经记录;这些 影响可能伴随着血压的变化。 此外，本发明还提供了一种方法， 前庭神经的切断会极大地损害血压 补偿猫的头向上倾斜，这表明前庭系统 参与纠正直立性低血压。 的存在 前庭交感神经反射作用于心血管系统， 令人惊讶的是，由于姿势的变化可能会挑战维持 稳定的血压，前庭系统提供输入， 当身体位置发生变化时发出信号，包括那些可能影响 循环，正在发生。 我们的长期目标是定义和研究 负责产生前庭交感神经反射的神经回路。 我们之前的研究表明，脑干两个区域的神经元， 尾侧延髓中缝核和面后下部 头端腹外侧延髓，将前庭信号传递给交感神经 脊髓中的节前神经元 建议的实验是 旨在发现哪些脑干神经元参与了 向这些脊髓投射细胞的神经递质输入。 通过利用 损伤技术和电生理学方法，我们将确定： (1)哪些前庭神经核介导前庭交感神经反射;（2） 脑干中间神经元将前庭信号传递到脊髓， 投射血管神经元;（3）小脑是否影响 前庭诱发的交感神经反应 因此，拟议的工作将 推进关于一个调查不足的基础科学知识， 潜在的重要神经机制参与控制 流通

Considerable evidence suggests that inputs from the vestibular system have direct and powerful influences on sympathetic outflow, as well as blood pressure. Electrical stimulation of the vestibular nerve alters activity recorded from sympathetic nerves innervating many body regions; these effects can be accompanied by changes in blood pressure. In addition, transection of the vestibular nerves greatly impairs blood pressure compensation to head-up tilt in cats, suggesting that the vestibular system participates in correcting orthostatic hypotension. The existence of vestibulosympathetic reflexes which act on the cardiovascular system is not surprising, since changes in posture can challenge the maintenance of stable blood pressure, and the vestibular system provides inputs which signal when changes in body position, including those which can affect circulation, are occurring. Our long-term goal is to define and study the neural circuitry responsible for producing vestibulosympathetic reflexes. Our previous work has shown that neurons in two regions of the brainstem, the caudal medullary raphe nuclei and the subretrofacial portion of the rostral ventro-lateral medulla, transmit vestibular signals to sympathetic preganglionic neurons in the spinal cord. The proposed experiments are aimed at discovering which brainstem neurons participate in relaying labyrinthine inputs to these spinally-projecting cells. By making use of lesioning techniques and electrophysiological methods, we will determine: (1) which vestibular nuclei mediate vestibulosympathetic reflexes; (2) which brainstem interneurons relay vestibular signals to spinally- projecting vasomotor neurons; and (3) whether the cerebellum influences vestibular-elicited sympathetic responses. The proposed work will thus advance the basic scientific knowledge about an underinvestigated and potentially important neural mechanism involved in the control of circulation.