Differential localization of 5-HT1 receptors on myenteric and submucosal neurons.
Differential localization of 5-HT1 receptors on myenteric and submucosal neurons.
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5-HT1 受体在肌肠和粘膜下神经元上的差异定位。
DOI：
10.1152/ajpgi.1988.255.5.g603
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发表时间：
1988
期刊：
影响因子：
--
通讯作者：
North,RA
中科院分区：
文献类型：
--
作者：
Galligan,JJ;Surprenant,A;Tonini,M;North,RA
利用豚鼠肠神经元进行细胞内记录，研究 5-羟色胺 (5-HT) 和 5-HT1 选择性激动剂 5-羧酰胺色胺 (5-CT) 和 8-羟基-2-(正二丙氨基)四氢萘 (DPAT) 对膜电位和突触电位的影响。当通过灌注应用这些激动剂时，大多数肌间 AH 神经元发生超极化；这种超极化是由于钾电导的增加造成的。在粘膜下神经元中从未观察到膜对 5-HT、5-CT 或 DPAT 的超极化。肌间神经丛 S 神经元记录的快速烟碱兴奋性突触后电位 (EPSP) 和慢速 EPSP 被 5-HT、5-CT 和 DPAT 抑制；肌间 AH 神经元中的缓慢 EPSP 也受到这些激动剂的抑制。从粘膜下 S 神经元记录的快速和慢速 EPSP 不受 5-CT 或 DPAT 的影响。然而，从粘膜下 AH 神经元记录的慢 EPSP 很容易被 5-CT 和 DPAT 阻断。结果表明，5-HT1受体位于肌间神经元的细胞体上，而不是粘膜下神经元的细胞体上。肌间神经元中释放快速和慢速突触电位的介质的神经末梢也具有 5-HT1 受体，并且可能源自其他肌间神经元；负责缓慢 EPSP 到 AH 神经元的神经末梢似乎是粘膜下神经丛中唯一表达 5-HT1 受体的元件。
Intracellular recordings were made from guinea pig enteric neurons, and the effects of 5-hydroxytryptamine (5-HT) and the 5-HT1 selective agonists 5-carboxyamidotryptamine (5-CT) and 8-hydroxy-2-(n-dipropylamino)tetralin (DPAT) were studied on membrane potential and synaptic potentials. Most myenteric AH neurons were hyperpolarized when these agonists were applied by superfusion; this hyperpolarization was due to an increase in potassium conductance. Membrane hyperpolarizations to 5-HT, 5-CT, or DPAT were never observed in submucous neurons. Fast nicotinic excitatory postsynaptic potentials (EPSPs) and slow EPSPs recorded from S neurons in the myenteric plexus were suppressed by 5-HT, 5-CT, and DPAT; slow EPSPs in myenteric AH neurons were also inhibited by these agonists. Fast and slow EPSPs recorded from submucous S neurons were not affected by 5-CT or DPAT. However, slow EPSPs recorded from submucous AH neurons were readily blocked by 5-CT and DPAT. The results indicate that 5-HT1 receptors are located on the cell bodies of myenteric but not submucosal neurons. The nerve terminals that release the mediator or mediators of fast and slow synaptic potentials in myenteric neurons also have 5-HT1 receptors and presumably arise from other myenteric neurons; the nerve terminals responsible for the slow EPSP to AH neurons seem to be the only elements of the submucous plexus that express 5-HT1 receptors.