Progressive potentiation of peptide release during a neuronal discharge.
Progressive potentiation of peptide release during a neuronal discharge.
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神经元放电期间肽释放的逐渐增强。
DOI：
10.1152/jn.1990.63.4.738
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发表时间：
1990
影响因子：
2.5
通讯作者：
Kaczmarek,LK
中科院分区：
文献类型：
--
作者：
Loechner,KJ;Azhderian,EM;Dreyer,R;Kaczmarek,LK
1. 为了响应电刺激，海兔的袋细胞神经元产生持续 20-40 分钟的后放电。在放电后，一些神经活性肽被释放。我们现在已经研究了其中两种肽——产卵激素（ELH）和酸性肽（AP）的释放时间过程。为了收集释放的肽，对袋细胞簇的动脉进行灌注。在后放电刺激之前、期间和之后，簇周围的介质（人工海水，ASW）每隔 5 分钟进行一次完全交换。使用高压液相色谱分析释放到外部介质中的肽。 2.刺激前，外部介质中未检测到ELH和AP。后放电开始后，ELH 和 AP 释放量逐渐增加，直至放电 15-20 分钟。在后放电结束时，ELH 和 AP 的释放恢复到控制水平。 3.与肽的释放模式相反，袋细胞神经元的放电率在放电后的第一分钟内达到最大，然后下降。 4.肽从轴突静脉曲张的释放发生在覆盖袋细胞神经元簇的血管结缔组织鞘内。因此，进行了实验以确定观察到的释放时间过程是否受到肽通过脉管系统扩散到外部介质的影响，特别是确定后放电 15-20 分钟的最大释放速率是否可以通过肽从神经突运输的延迟来解释。（摘要截断为 250 字）
1. In response to electrical stimulation, the bag cell neurons of Aplysia generate an afterdischarge that lasts 20-40 min. During this afterdischarge several neuroactive peptides are released. We have now studied the time course of release of two of these peptides, egg-laying hormone (ELH) and acidic peptide (AP). For the collection of released peptides, the artery to the bag cell clusters was perfused. The medium surrounding the clusters (artificial seawater, ASW) was completely exchanged at 5-min intervals before, during, and after stimulation of an afterdischarge. Peptides released into the external medium were analyzed with the use of high-pressure liquid chromatography. 2. Before stimulation, no detectable ELH and AP were found in the external medium. After the onset of an afterdischarge, the amount of ELH and AP released increased progressively until 15-20 min of firing. Toward the conclusion of an afterdischarge, the release of ELH and AP returned to control levels. 3. In contrast to the pattern of release of the peptides, the firing rate of the bag cell neurons is maximal within the first minute of afterdischarge and thereafter declines. 4. Release of the peptides from axonal varicosities occurs within the vascularized connective-tissue sheath that covers the clusters of bag cell neurons. Experiments were therefore carried out to establish whether the observed time course of release is affected by diffusion of the peptides through the vasculature into the external medium and, in particular, to determine whether the maximal rate of release at 15-20 min into the afterdischarge could be accounted for by a delay in transport of peptides from the neurites.(ABSTRACT TRUNCATED AT 250 WORDS)