VESTIBULAR INFLUENCES ON THE SYMPATHETIC NERVOUS SYSTEM

前庭神经的电刺激产生症状的变化， 感觉流出和血压（Uchino等人，1970;石川等人， 1979年）。此外，前庭病变影响立位反射 （心血管对体位变化的反应）：此类病变 大大削弱猫对60度倾斜的血压补偿（Doba和 Reis，1974; Huang等人，1977年）。前庭交感神经的发生 对抗直立性低血压的反射并不意外; 前庭感受器告知神经系统头部的变化 位置，从而改变姿势。因为生理反应 直立性低血压是交感神经流出增加（Gauer和 Thron，1965年），这似乎是实际的输入信号的变化， 姿势影响自主神经系统。初步研究 揭示了至少两个脑干区域的神经元中已知含有一种 高密度的心脏调节神经元，腹外侧延髓和 旁正中网状核，接收前庭输入。此外，本发明还提供了一种方法， 来自颈动脉窦和迷路的输入被证明会聚在 在这些地区的单位。拟议的研究将利用这两个 电和自然前庭刺激，并将分析前庭 脑干心脏调节神经元的输入以及前庭引起的 从交感神经记录的反射。这些实验将证明 哪些下行通路将前庭信号传递到交感神经 神经节前神经元，并表征这些途径的输入。这 信息将揭示哪些外周终末器官（半规管或 耳石器官）在产生通气交感神经反射中是重要的。 此外，后肢的躯体输入 对前庭交感神经通路的神经元的影响 考虑了

Electrical stimulation of the vestibular nerve produces changes in sympa- thetic outflow and blood pressure (Uchino et al., 1970; Ishikawa et al., 1979). In addition, vestibular lesions affect orthostatic reflexes (cardiovascular responses to a change in body position): such lesions greatly impair blood pressure compensation to 60 deg tilt in cats (Doba and Reis, 1974; Huang et al., 1977). The occurrence of vestibule-sympathetic reflexes which counteract orthostatic hypotension is not unexpected; vestibular receptors inform the nervous system about changes in head position, and thus changes in posture. Since the physiological response to orthostatic hypotension is an increase in sympathetic outflow (Gauer and Thron, 1965), it seems practical for inputs which signal a change in posture to influence the autonomic nervous system. Preliminary studies revealed that neurons in at least two brainstem regions known to contain a high density of cardioregulatory neurons, the ventrolateral medulla and the paramedian reticular nucleus, receive vestibular inputs. In addition, inputs from the carotid sinus and labyrinth were shown to converge on single units in these regions. The proposed studies will utilize both electrical and natural vestibular stimulation and will analyze vestibular inputs to brainstem cardioregulatory neurons as well as vestibular-elicited reflexes recorded from sympathetic nerves. These experiments will show which descending pathways convey vestibular signals to sympathetic preganglionic neurons and characterize the inputs to these pathways. This information will reveal which peripheral endorgans (semicircular canals or otolith organs) are important in producing ventibulo-sympathetic reflexes. In addition, the possibility that somatic inputs from the hindlimb converge on neurons that are part of the vestibulo-sympathetic pathway will be considered.