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Effect of electrical stimulation of rostral ventrolateral medulla on unit discharges of sympathetic preganglionic neurons in the rat

Zhou Zhengfeng, Ku Yunhui

Department of Physiology, Beijing Medical University. Beijing, China

Abstract

Experiments were performed on urethane-anesthetized and d-tubocurarine-immobilized rats under artificial respiration. Single unit discharges of sympathetic preganglionic neurons (SPN) in T2 segment of the spinal cord were recorded extracellularly. The SPNs were identified by their antidromic response to stimulation of the ipsilateral cervical sympathetic trunk. Among 80 identified SPIVs, 40 were Spontaneously active and 40 were silent. The axonal conduction velocities of SPNs were 0.59-3.75 m/s. Electrical stimulation of ipsilateral rostral ventrolateral medulla (RVL) could excite most (19/25) spontaneously active SPNs but only a few silent cells (4/23) (latencies: 6-115ms). Electrical stimulation of contralateral RVL had similar results: 6 out of 9 spontaneously active SPNs and 3 out of 17 silent SPNs were activated (latencies: 11-105ms). These results indicate that RVL 1ias an excitatory influence on bilateral SPNs.

Key words: Rostral ventrolateral medulla;Sympathetic preganglionic neuron;Unit discharge

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Citing This Article：

Zhou Zhengfeng, Ku Yunhui. Effect of electrical stimulation of rostral ventrolateral medulla on unit discharges of sympathetic preganglionic neurons in the rat. Acta Physiol Sin 1987; 39 (2): (in Chinese with English abstract).