Analysis of the responses of myenteric neurons in the small intestine to chemical stimulation of the mucosa.
Analysis of the responses of myenteric neurons in the small intestine to chemical stimulation of the mucosa.
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DOI：
10.1152/ajpgi.1997.273.2.g422
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发表时间：
1997-08
期刊：
影响因子：
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通讯作者：
Paul P. Bertrand;Wolf A. A. Kunze-Wolf-A.-A.-Kunze-2233345542;J. Bornstein;John B. Furness;M. L. Smith
中科院分区：
文献类型：
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作者：
Paul P. Bertrand;Wolf A. A. Kunze-Wolf-A.-A.-Kunze-2233345542;J. Bornstein;John B. Furness;M. L. Smith
用传统的细胞内记录技术，获得了豚鼠小肠粘膜局部应用化学物质时肌间AH和S神经元的反应。将制备物解剖以显示肠周长的一半上的肌间神经丛，其中一半上具有完整的粘膜。将神经元刺穿在暴露的一半内，而将缓冲盐水中的潜在刺激剂暂时施加到粘膜上，距离刺穿处1-1.5 mm。刺激物引起AH神经元的动作电位（AP），而不是由突触活动引起的。AH神经元也以慢兴奋性突触后电位（EPSP）反应。S神经元通过快和慢EPSP被突触激活，但不是非突触激活。施用低pH（3-5）或高pH（9-11）的溶液的粘液素都是有效的刺激剂。中性pH的溶液，也是温和机械刺激的对照，通常是无效的。短链脂肪酸醋酸盐（pH 7.2）和5-羟色胺都会引起每种神经元类型的反应。我们的结论是，豚鼠回肠末端的肌间AH神经元是初级传入神经元，响应于各种粘膜施加的化学刺激与AP爆发。此外，慢EPSP向AH神经元的生理诱发传递表明初级传入神经元在自我增强网络中互连。S神经元是反射通路中的二级或高级神经元。
Responses of myenteric AH and S neurons to local application of chemicals to the mucosa of the guinea pig small intestine were obtained using conventional intracellular recording techniques. Preparations were dissected to reveal the myenteric plexus over one-half of the circumference of the gut with intact mucosa on the the half. Neurons were impaled within the exposed one-half, whereas potential stimulants, in buffered saline, were transiently applied to the mucosa, 1-1.5 mm circumferential from the impalement. The stimulants elicited action potentials (AP) in AH neurons that did not arise from synaptic activity. AH neurons also responded with slow excitatory postsynaptic potentials (EPSP). S neurons were activated synaptically, via fast and slow EPSP, but not nonsynaptically. Mucosal application of solutions of a low pH (3-5) or a high pH (9-11) were both effective stimulants. Solutions of a neutral pH, which was also a control for mild mechanical stimulation, were usually ineffective. Both a short-chain fatty acid, acetate (pH 7.2), and 5-hydroxytryptamine elicited responses in each neuronal type. We conclude that myenteric AH neurons of the guinea pig distal ileum are primary afferent neurons that respond to a variety of mucosally applied chemical stimuli with burst of AP. In addition, the physiologically evoked transmission of slow EPSP to AH neurons suggests that primary afferent neurons interconnect in a self-reinforcing network. S neurons are second or higher order neurons in the reflex pathways.