Does substance P mediate slow synaptic excitation within the myenteric plexus?
Does substance P mediate slow synaptic excitation within the myenteric plexus?
复制标题
P 物质是否介导肌间神经丛内的缓慢突触兴奋？
作者：
Y. Katayama;R. North
P 物质在中枢 1-6 和外周 7-9 神经系统神经元内的广泛分布表明它可能是神经元功能的重要调节剂。虽然通过微离子电渗疗法10-14 P物质通常会兴奋中枢神经元，但这种兴奋相当缓慢，这可能不适合快速作用的神经递质11的作用。在本报告中，我们证明 P 物质对肌间神经元膜具有强大的去极化作用，这主要是通过静息钾电导的失活来实现的。此外，在几个神经元中，我们观察到突触诱发的去极化，其具有与 P 物质产生的去极化相似的时间过程和离子机制。鉴于肌间神经丛在神经末梢和静脉曲张中含有 P 物质的证据，这一点特别令人感兴趣8,9。
THE widespread distribution of substance P within neurones of the central1–6 and peripheral7–9 nervous systems has led to the suggestion that it may be an important modulator of neuronal function. Although when applied by microiontophoresis10–14 substance P usually excites central neurones, this excitation is rather slow and this may not be appropriate to the role of a rapidly acting neurotransmitter11. In this report we show substance P to have a powerful depolarising action on the membrane of myenteric neurones and that this is brought about primarily by an inactivation of resting potassium conductance. Furthermore, in several neurones we have observed synaptically evoked depolarisations which have a time course and ionic mechanism similar to the depolarisations produced by substance P. This is of particular interest in view of the evidence that the myenteric plexus contains substance P within nerve terminals and varicosities8,9.