Neuronal activity and retrograde intra-axonal transport.

一般认为突触前神经末梢的突触囊泡与突触前末梢膜融合并释放递质。产生的额外的终末膜将通过网格蛋白介导的胞饮作用被吸收到终末。因此，突触激活会增加末端被包膜囊泡的数量，也可能增加沿轴突逆行运输的囊泡的数量。我们试图用鱼雷和纳克电器官的胆碱能神经末梢来澄清这一假设。在刺激电神经的同时快速冻结末端区域。电镜观察显示突触末端有许多突触囊泡，但与对照组相比无显著差异。我们还研究了神经刺激下的轴突逆行转运。利用干涉对比显微镜对电神经细支的计算机增强视频图像分析了粒子沿轴突的运动。但是，它们的运动不会因神经刺激而改变。

It is generally accepted that synaptic vesicles in the pre-synaptic nerve terminal fuse with the presynaptic terminal membrane and release the transmitter. The resulted extra terminal membrane will be uptaken into the terminal by clathrin mediated pinocytosis. Therefore, the synaptic activation will increase the number of coated vesicles in the terminal and also may increase the number of retrogradely transporting vesicles along the axon. We have tried to clarify the assumption using cholinergic nerve terminals of electric organ of Torpedo and Narke. The terminal region was quick-frozen while stimulating the clectric nerve. The replica examined by electron microscopy showed many synaptic vesicles in the terminal, but no significant differences between stimulated one and control. We also examined the retrograde axonal transport upon nerve stimulations. The movement of particles along the axon was analyzed by computer enhanced video image of the interference contrast microscopy of the fine branches of the electric nerve. But, their movements was not modified by stimulation of the nerve.