Max-Planck-Institut für biophysikalische Chemie, Am Fassberg 11, 37077, Goettingen, Germany.
Pflugers Arch. 2018 Jan;470(1):7-11. doi: 10.1007/s00424-017-2051-6. Epub 2017 Aug 11.
Many of the molecular players in the stimulus-secretion chain are similarly active in neurosecretion and catecholamine release. Therefore, studying chromaffin cells uncovered many details of the processes of docking, priming, and exocytosis of vesicles. However, morphological specializations at synapses, called active zones (AZs), confer extra speed of response and another layer of control to the fast release of vesicles by action potentials. Work at the Calyx of Held, a glutamatergic nerve terminal, has shown that in addition to such rapidly released vesicles, there is a pool of "Slow Vesicles," which are held to be perfectly release-competent, but lack a final step of tight interaction with the AZ. It is argued here that such "Slow Vesicles" have many properties in common with chromaffin granules. The added complexity in the AZ-dependent regulation of "Fast Vesicles" can lead to misinterpretation of data on neurosecretion. Therefore, the study of Slow Vesicles and of chromaffin granules may provide a clearer picture of the early steps in the highly regulated process of neurosecretion.
许多参与刺激-分泌链的分子在神经分泌和儿茶酚胺释放中也同样活跃。因此，研究嗜铬细胞揭示了许多关于囊泡对接、引发和胞吐作用的过程的细节。然而，突触处的形态特化，称为活性区（AZ），赋予了快速释放囊泡的额外响应速度和另一个层次的控制，由动作电位触发。在钙调蛋白结合的 Calyx of Held（一种谷氨酸能神经末梢）的研究表明，除了这种快速释放的囊泡外，还有一个“慢速囊泡”库，它们被认为完全具有释放能力，但缺乏与 AZ 的最后一步紧密相互作用。这里认为，这种“慢速囊泡”与嗜铬颗粒具有许多共同的特性。在 AZ 依赖性的“快速囊泡”调节中增加的复杂性可能导致对神经分泌数据的误解。因此，对慢速囊泡和嗜铬颗粒的研究可能为高度调控的神经分泌过程的早期步骤提供更清晰的图像。
