Evoked release of acetylcholine from the growing embryonic neuron.
Evoked release of acetylcholine from the growing embryonic neuron.
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生长中的胚胎神经元诱发乙酰胆碱的释放。
DOI：
10.1073/pnas.84.8.2540
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发表时间：
1987
影响因子：
11.1
通讯作者：
Poo,MM
中科院分区：
文献类型：
--
作者：
Sun,YA;Poo,MM
在非洲爪蟾细胞培养中，用一片胚胎肌膜作为探针，测定生长中脊髓神经元乙酰胆碱（AcCho）的释放。在细胞外刺激神经元的索马，并在生长锥，沿着轴突，和附近的索马监测诱发的乙酰胆碱释放。对于大多数的神经元研究，一个简短的阈上刺激的索马触发脉冲的乙酰胆碱释放的生长锥。这种释放表现出许多特征，让人想起在成熟的神经肌肉突触的神经末梢的递质释放：它发生在几毫秒内的刺激后，依赖于细胞外Ca 2+浓度，并表现出抑郁症和增强过程中和高频刺激后，分别。类似的诱发释放也观察到只有在选定的点沿着的神经突，并延长阈上刺激诱导释放的索马。这些结果表明，一些正在生长的脊髓神经元已经获得了大量的AcCho分子，以及在生长锥的兴奋-分泌耦合的有效机制，准备与靶肌肉细胞建立功能性接触。这一观点进一步得到以下发现的支持：诱发的AcCho释放能够在神经突-肌肉接触后的第一分钟内诱导肌细胞的阈上兴奋。
An excised patch of embryonic muscle membrane was used as a probe for measuring the release of acetylcholine (AcCho) from growing spinal neurons in Xenopus cell culture. The neuron was stimulated extracellularly at the soma, and the evoked AcCho release was monitored at the growth cone, along the neurite, and near the soma. For a majority of the neurons studied, a brief suprathreshold stimulation of the soma triggered a pulse of AcCho release from the growth cone. This release showed many of the characteristics reminiscent of the transmitter release at the nerve terminal of a mature neuromuscular synapse: it occurs within a few ms following the stimulation, depends on extracellular Ca2+ concentration, and exhibits depression and potentiation during and after high-frequency stimulation, respectively. Similar evoked release was also observed only at selected points along the neurite, and prolonged suprathreshold stimulus was required to induce release from the soma. These results indicate that some of the growing spinal neurons have acquired a substantial number of AcCho molecules as well as an efficient mechanism for excitation-secretion coupling at the growth cone, ready for establishing functional contact with the target muscle cell. This notion was further supported by the finding that the evoked AcCho release is capable of inducing suprathreshold excitation of the muscle cell within the first minute following neurite-muscle contact.