Stöckel K, Schwab M, Thoenen H
Brain Res. 1975 Nov 28;99(1):1-16. doi: 10.1016/0006-8993(75)90604-6.
In previous studies it has been shown that nerve growth factor (NGF) is taken up with high selectivity by adrenergic and sensory nerve terminals and is transported retrogradely to the corresponding cell bodies by a colchicine sensitive mechanism 10,11,23. The present study was designed to investigate whether this retrograde transport of NGF depends on properties of the nerve terminals which are common to all the neurons or restricted to those which respond to NGF either during the whole life cycle (adrenergic neurons) or during a restricted period of embryonic development (sensory neurons). In order to investigate the retrograde transport of NGF in motor neurons we injected [125I]NGF into the musculus deltoideus and measured the side differences of accumulation of radioactivity in the spinal cord (C6-C8) from 4-48 h. At no time was there a preferential accumulation of radioactivity on the injected side. In contrast, tetanus toxin was accumulated preferentially on the injected side and an approximate rate of transport of 7.5 mm/h was calculated. Astonishingly there was also a retrograde transport of tetanus toxin in sensory and adrenergic neurons. The rate of transport was identical to that of NGF and the transport could be blocked by transection of the corresponding nerve fibers and local administration of colchicine. After unilateral injection of [125I]tetanus toxin into the forepaw or the musculus deltoideus light microscopic autoradiographs revealed heavily labeled neuronal cell bodies in the dorsal root ganglia or the ventrolateral spinal cord of the injected side. It is concluded that the retrograde transport of [125I]NGF depends on properties of the neuronal membrane which are specific for adrenergic and sensory neurons, whereas that of tetanus toxin is determined by features which are common to all, or at least to all peripheral, neurons. The fact that the rate of transport for both NGF and tetanus toxin is identical in all examined neurons, supports the hypothesis that the specificity of retrograde transport is determined by specific uptake sites in the neuronal membrane whereas the retrograde transport system is non-specific.
在以往的研究中已经表明，神经生长因子（NGF）被肾上腺素能和感觉神经末梢高度选择性地摄取，并通过一种秋水仙碱敏感机制逆行运输到相应的细胞体[10,11,23]。本研究旨在探讨NGF的这种逆行运输是否取决于所有神经元共有的神经末梢特性，还是仅限于那些在整个生命周期（肾上腺素能神经元）或胚胎发育的受限时期（感觉神经元）对NGF有反应的神经末梢特性。为了研究运动神经元中NGF的逆行运输，我们将[125I]NGF注入三角肌，并在4至48小时内测量脊髓（C6 - C8）中放射性积累的左右差异。在任何时候，注射侧都没有放射性的优先积累。相比之下，破伤风毒素优先在注射侧积累，并计算出约7.5毫米/小时的运输速率。令人惊讶的是，破伤风毒素在感觉神经元和肾上腺素能神经元中也有逆行运输。运输速率与NGF相同，并且运输可以通过切断相应的神经纤维和局部施用秋水仙碱来阻断。在将[125I]破伤风毒素单侧注入前爪或三角肌后，光学显微镜放射自显影片显示注射侧的背根神经节或脊髓腹外侧有大量标记的神经元细胞体。得出的结论是，[125I]NGF的逆行运输取决于肾上腺素能和感觉神经元特有的神经元膜特性，而破伤风毒素的逆行运输则由所有神经元或至少所有外周神经元共有的特征决定。在所有检查的神经元中，NGF和破伤风毒素的运输速率相同这一事实支持了这样的假设，即逆行运输的特异性由神经元膜中的特定摄取位点决定，而逆行运输系统是非特异性的。
