大鼠坐骨神经胆碱能神经元中囊泡乙酰胆碱转运体（VAChT）的快速轴突运输。

Fast axonal transport of the vesicular acetylcholine transporter (VAChT) in cholinergic neurons in the rat sciatic nerve.

作者信息

Li J Y, Dahlström A M, Hersh L B, Dahlström A

机构信息

Department of Anatomy and Cell Biology, University of Göteborg, Medicinaregatan, Sweden.

出版信息

Neurochem Int. 1998 May-Jun;32(5-6):457-67. doi: 10.1016/s0197-0186(97)00122-8.

DOI:10.1016/s0197-0186(97)00122-8

PMID:9676745

Abstract

The sciatic nerve, as a part of the peripheral nervous system (PNS), has been used to study axonal transport for decades. It contains motor, sensory as well as autonomic axons. The present study has concentrated on the axonal transport of the synaptic vesicle acetylcholine transporter (VAChT), using the "stop-flow/nerve crush" method. After blocking fast axonal transport by means of a crush, distinct accumulations of various synaptic vesicle proteins, including VAChT, and peptides developed during the first hour after crush-operation and marked increases were observed up to 8 h post-operative. Semiquantitative analysis, using cytofluorimetric scanning (CFS) of immuno-incubated sections, revealed a rapid rate of accumulation proximal to the crush, and that the ratio between distal accumulations (organelles in retrograde transport) and proximal accumulations (organelles in anterograde transport) was about 40%. Most synaptic vesicle proteins were colocalized in the axons proximal to the crush. VAChT-immunoreactive axons were also immunoreactive for choline acetyltransferase (ChAT). Autonomic axons with VAChT also contained VIP-LI. The results demonstrate (1) that VAChT, as well as other synaptic vesicle proteins, is transported with fast axonal transport in motor axons as well as in autonomic post-ganglionic neurons in this nerve, (2) VAChT colocalized in motor axons with SV2 as well as with synaptophysin, indicating storage in the same axonal particle, (3) in the autonomic postganglionic sympathetic cholinergic fibres, VAChT colocalized with VIP, but VIP-LI was present in rather large granular structures while VAChT-LI was present mostly as small granular elements, (4) in motor as well as in autonomic axons ChAT-LI was present in VAChT-positive axons, and (5) the ratio of recycling (retrogradely accumulated) VAChT-IR was about 40%, in contrast to the recycling fraction of synaptophysin that was about 70%.

摘要

坐骨神经作为周围神经系统（PNS）的一部分，几十年来一直被用于研究轴突运输。它包含运动、感觉以及自主神经轴突。本研究采用“停流/神经挤压”方法，聚焦于突触囊泡乙酰胆碱转运体（VAChT）的轴突运输。通过挤压阻断快速轴突运输后，在挤压操作后的第一小时内观察到包括VAChT在内的各种突触囊泡蛋白和肽的明显聚集，并且在术后8小时观察到显著增加。使用免疫孵育切片的细胞荧光扫描（CFS）进行半定量分析，结果显示在挤压近端积累速度很快，并且远端积累（逆行运输中的细胞器）与近端积累（顺行运输中的细胞器）的比例约为40%。大多数突触囊泡蛋白在挤压近端的轴突中共定位。VAChT免疫反应性轴突对胆碱乙酰转移酶（ChAT）也有免疫反应。含有VAChT的自主神经轴突也含有血管活性肠肽免疫反应性（VIP-LI）。结果表明：（1）VAChT以及其他突触囊泡蛋白在该神经的运动轴突和自主神经节后神经元中通过快速轴突运输进行运输；（2）VAChT在运动轴突中与突触囊泡蛋白2（SV2）以及突触素共定位，表明储存在同一轴突颗粒中；（3）在自主神经节后交感胆碱能纤维中，VAChT与VIP共定位，但VIP-LI存在于相当大的颗粒结构中，而VAChT-LI大多以小颗粒成分存在；（4）在运动轴突和自主神经轴突中，ChAT-LI存在于VAChT阳性轴突中；（5）循环利用（逆行积累）的VAChT免疫反应性（VAChT-IR）比例约为40%，而突触素的循环利用比例约为70%。