Jordan D, Khalid M E, Schneiderman N, Spyer K M
Pflugers Arch. 1982 Nov 11;395(3):244-50. doi: 10.1007/BF00584817.
The origins of preganglionic vagal neurons which slow the heart in the rabbit have been examined with standard neurophysiological stimulation and recording techniques. The activity of 216 neurones projecting to the right cervical vagus nerve have been recorded in localized areas of the brain stem. Thirty-six of these neurones were classified as cardiomotor neurones since they had properties similar to those described for such neurones in the cat. All had efferent axons in the range of B fibres. They could be synaptically activated by electrical stimulation of the ipsilateral aortic nerve which in the rabbit is solely barosensory. The majority of these neurones (70%) were spontaneously active and those which were normally silent could be made to fire by iontophoretic application of DL-homocysteic acid (an excitant amino acid). This spontaneous, or evoked, activity showed evidence of a pulse rhythm (of baroreceptor origin) and respiratory modulation (firing predominantly during expiration). In response to application of DL-homocysteic acid, the neuronal excitation was usually accompanied by a small but significant bradycardia. Histological examination showed that these neurones were located in both the dorsal vagal nucleus and the nucleus ambiguus.
利用标准的神经生理学刺激和记录技术，研究了家兔体内使心脏活动减慢的节前迷走神经神经元的起源。已在脑干的局部区域记录了216个投射至右侧颈迷走神经的神经元的活动。其中36个神经元被归类为心动运动神经元，因为它们具有与猫体内此类神经元相似的特性。所有神经元的传出轴突均在B纤维范围内。对同侧主动脉神经进行电刺激可使它们发生突触激活，在家兔体内，主动脉神经仅具有压力感受功能。这些神经元中的大多数（70%）具有自发活动，而那些通常沉默的神经元可通过离子电渗法施加DL-高胱氨酸（一种兴奋性氨基酸）来激发放电。这种自发或诱发的活动显示出脉搏节律（起源于压力感受器）和呼吸调制（主要在呼气时放电）的迹象。在施加DL-高胱氨酸后，神经元兴奋通常伴有轻微但显著的心动过缓。组织学检查表明，这些神经元位于迷走神经背核和疑核中。
