Synaptic mechanisms involved in the inspiratory modulation of vagal cardio‐inhibitory neurones in the cat.
Synaptic mechanisms involved in the inspiratory modulation of vagal cardio‐inhibitory neurones in the cat.
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猫迷走心脏抑制神经元吸气调节涉及的突触机制。
DOI：
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发表时间：
1984
期刊：
影响因子：
--
通讯作者：
K. Spyer
中科院分区：
文献类型：
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作者：
M. Gilbey;D. Jordan;D. Richter;K. Spyer
通过电生理学和神经药理学技术研究了猫疑核迷走心脏抑制神经元活动的呼吸调节。研究的所有 24 个迷走神经传出神经元的轴突具有指示 B 纤维的传导速度，并投射到迷走神经的右心分支。他们的自发活动或 DL-同型半胱氨酸 (DLH) 诱发的活动在吸气阶段显示出显着减少，并且都显示出接受压力感受器输入的迹象。 DLH 的离子电渗应用总是会兴奋心脏迷走神经运动神经元 (c.v.m.s)。对这些相同的细胞应用乙酰胆碱会导致测试的 15 个神经元中的 12 个神经元的放电率降低。在这十二个细胞中的十个中，同时应用阿托品拮抗乙酰胆碱的作用。单独使用阿托品可增强神经元放电，特别是在吸气时。两个 c.v.m.s. 已进行稳定的细胞内记录。这些在吸气过程中受到抑制。在吸气期间输入电阻显着下降，注射氯化物将超极化波逆转为去极化波，表明这是由氯化物介导的抑制性突触后电位（i.p.s.p.s）引起的。这些 c.v.m.s 在第一阶段呼气时被激活，并在第二阶段呼气时表现出微弱且可变的抑制波。在神经元输入电阻降低期间，脉冲节律去极化电位的幅度降低。结论是，c.v.m.s 在吸气后接收兴奋性输入，在吸气期间接收强大的抑制性突触输入。讨论了这些观察结果对心肺反射生理学的影响。
The respiratory modulation of the activity of vagal cardio‐inhibitory neurones of the nucleus ambiguus of the cat has been investigated by electrophysiological and neuropharmacological techniques. All twenty‐four vagal efferent neurones studied had axons with conduction velocities indicative of B fibres and projected to the right cardiac branches of the vagus. Their spontaneous or DL‐homocysteic acid (DLH)‐evoked activity showed a marked reduction during the phase of inspiration and all showed signs of receiving a baroreceptor input. Ionophoretic application of DLH always excited cardiac vagal motoneurones (c.v.m.s). Application of acetylcholine to these same cells provoked a decrease in firing rate in twelve of the fifteen neurones tested. In ten of these twelve cells simultaneous application of atropine antagonized the effect of acetylcholine. Atropine applied alone enhanced neuronal firing, particularly in inspiration. Stable intracellular recordings have been made from two c.v.m.s. These were inhibited during inspiration. Input resistance fell markedly during inspiration and injection of chloride reversed this wave of hyperpolarization to a wave of depolarization indicating that this resulted from chloride‐mediated inhibitory post‐synaptic potentials (i.p.s.p.s). These c.v.m.s were activated during Stage I expiration, and showed a weak and variable wave of inhibition in Stage II expiration. Pulse‐rhythmic depolarizing potentials were reduced in their amplitudes during the periods of decreased neurone input resistance. It is concluded that c.v.m.s receive an excitatory input during post‐inspiration and a powerful inhibitory synaptic input during inspiration. The implications of these observations for the physiology of cardiorespiratory reflexes are discussed.
毒蕈碱胆碱能受体调节人类迷走神经心脏反应。
DOI：
10.1016/0165-1838(83)90080-2
发表时间：
1983
期刊：
Journal of the autonomic nervous system
影响因子：
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作者：
Raczkowska,M;Eckberg,DL;Ebert,TJ
通讯作者：
Ebert,TJ