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新生大鼠延髓面神经后核内侧区呼吸节律起步神经元的确认及分类

何国军, 吴中海

南方医科大学生理学教研室，广州 510515；解放军第四五四医院神经科，南京 210002

摘要

本研究旨在为延髓面神经后核内侧区(medial region of nucleus retrofacialis, mNRF)是基本节律性呼吸发生部位的学说提 供直接的实验依据。仿Suzue 方法制作新生大鼠含有舌下神经根及mNRF 的离体延髓脑片标本，以吸附电极记录舌下神经 根呼吸节律性放电活动(respiratory rhythmic discharge activity, RRDA)作为呼吸活动的指标，采用全细胞膜片钳记录模式在 mNRF同步记录呼吸神经元电活动。观察呼吸非起步神经元、起步神经元的电生理学特征及后者对Cd2+ 敏感性。在mNRF， 呼吸起步神经元放电具有自发性、节律性及电压依赖性发放反应的特征，给予去极化/ 超极化电流时会产生异位发放。起 步、非起步呼吸神经元的各种电学特性(膜电容、输入电阻、内向漏电流)之间无显著性差异。在Sprague-Dawley 新生大 鼠，呼吸中枢以Cd2+ 非敏感性呼吸起步神经元为主。本研究进一步表明，mNRF 是基本节律性呼吸发生的部位。

关键词： 呼吸中枢; 延髓; 面神经后核内侧区; 呼吸节律

分类号：R338

[Identification and classification of respiratory pacemaker neurons in the medial region of nucleus retrofacialis in neonatal rats.] [Ariticle in Chinese]

HE Guo-Jun, WU Zhong-Hai

Department of Physiology, Southern Medical University, Guangzhou 510515, China； Department of Neurology, No.454 Hospital of PLA, Nanjing 210002, China

Abstract

The aim of the present study is to supply direct experimental proof that the medial region of nucleus retrofacialis (mNRF) is the site generating basic rhythm of respiration. Medullary slices of neonatal Sprague-Dawley rats, including hypoglossal nerve root and mNRF, were made according to Suzue’s method. Simultaneous recordings of the respiratory rhythmic discharge activity (RRDA) in hypoglossal nerve root with suction electrode and the respiratory neuronal discharge in the mNRF with whole cell patch clamp were performed on the brainstem slice in vitro. Not only the electrophysiological characteristics of pacemaker and non-pacemaker neurons, but the cadmium-sensitivity of pacemaker neurons was observed. The nature of the discharge in the respiratory pacemaker neurons in mNRF was spontaneous, rhythmical and voltage-dependent burst behavior, generating an ectopic burst in response to a depolarizing or hyperpolarizing current. There were no significant differences in capacitance of membrane (Cm), input resistance of membrane (Rm) and leak inward current (Ileak) between the pacemaker neurons and the non-pacemaker ones. Moreover, most pacemaker neurons in the mNRF were Cd2+-insensitive. In conclusion, these results support the idea that the mNRF is the site generating basic respiratory rhythm.

Key words: respiratory centre; medulla; the medial region of nucleus retrofacialis; respiratory rhythm

收稿日期：2008-05-13　　录用日期：2008-11-26

通讯作者：吴中海　　E-mail: wzh@fimmu.com

引用本文：

何国军, 吴中海. 新生大鼠延髓面神经后核内侧区呼吸节律起步神经元的确认及分类[J]. 生理学报 2009; 61 (1): 79-84.

HE Guo-Jun, WU Zhong-Hai. [Identification and classification of respiratory pacemaker neurons in the medial region of nucleus retrofacialis in neonatal rats.] [Ariticle in Chinese] . Acta Physiol Sin 2009; 61 (1): 79-84 (in Chinese with English abstract).