COINJECTION OF WHEAT-GERM AGGLUTININ-HRP AND CHOLERAGENOID-HRP INTO THE SCIATIC-NERVE OF THE RAT BLOCKS TRANSGANGLIONIC TRANSPORT
COINJECTION OF WHEAT-GERM AGGLUTININ-HRP AND CHOLERAGENOID-HRP INTO THE SCIATIC-NERVE OF THE RAT BLOCKS TRANSGANGLIONIC TRANSPORT
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DOI：
10.1177/43.5.7730587
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发表时间：
1995-05-01
影响因子：
3.2
通讯作者：
BASBAUM, AI
中科院分区：
文献类型：
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作者：
LIU, HT;LLEWELLYNSMITH, IJ;BASBAUM, AI
我们报告的跨神经节和逆行标记的大鼠脊髓后，共同注射的示踪剂小麦胚芽凝集素-HRP（WGA-HRP）和类霍乱毒素-HRP（CTB-HRP）到坐骨神经的令人惊讶的损失。注射WGA-HRP单独产生的transganglionic标签的模式与运输的小直径初级传入纤维。在同侧背根神经节（DRG）内有小细胞体被标记，在腰髓浅背角内有密集终末标记。注射CTB-HRP单独产生的transganglionic标记的模式与运输大直径的初级传入纤维。背根神经节内有大的细胞体被标记，脊髓固有核（层III-V）内有密集的终末标记。CTB-HRP也产生广泛的腹角运动神经元逆行标记。当两种示踪剂共注射时，我们发现在同侧DRG中几乎没有标记细胞，并且在腰髓中几乎完全丧失了跨神经节末端标记。运动神经元的逆行标记也显著减少。即使当示踪剂之一（例如，WGA-HRP）在第一示踪剂（例如，CTB-HRP），检测到抑制性相互作用。标记模式始终是第一个示踪剂注射的特征。由于在DRG和脊髓中观察到标记的损失，我们得出结论，相互抑制的相互作用发生在由坐骨神经和/或运输到背根神经节和超越的机制的示踪剂的摄取过程中。即使在时间和空间上分开注射时也观察到标记减少的事实表明，潜在的机制比仅仅产生不能被坐骨神经吸收和运输的WGA-HRP/CTB-HRP复合物更复杂。
We report on the surprising loss of transganglionic and retrograde labeling in the spinal cord of the rat after co-injection of the tracers wheat germ agglutinin-HRP (WGA-HRP) and choleragenoid toxin-HRP (CTB-HRP) into the sciatic nerve. Injection of WGA-HRP alone produced a pattern of transganglionic label consistent with transport by small-diameter primary afferent fibers. Small cell bodies were labeled in the ipsilateral dorsal toot ganglion (DRG) and there was dense terminal labeling in the superficial dorsal horn of the lumbar spinal cord. Injection of CTB-HRP alone produced a pattern of transganglionic labeling consistent with transport by large-diameter primary afferent fibers. Large cell bodies were labeled in the DRG and there was dense terminal labeling in the nucleus proprius (Laminae III-V) in the spinal cord. CTB-HRP also produced extensive retrograde labeling of ventral horn motor neurons. When the two tracers were co-injected, we found few labeled cells in the ipsilateral DRG and there was almost complete loss of transganglionic terminal labeling in the lumbar spinal cord. Retrograde labeling of motor neurons was also significantly reduced. Even when one of the tracers (e.g., WGA-HRP) was injected 24 hr after and up to 10 mm proximal to the site of the first tracer (e.g., CTB-HRP), an inhibitory interaction was detected. The labeling pattern was always characteristic of the first tracer injected. Since the loss of labeling was observed in the DRG and in the spinal cord, we conclude that the mutually inhibitory interactions occur during uptake of the tracers by the sciatic nerve and/or in the mechanism of transport to the dorsal root ganglion and beyond. The fact that reduced labeling was observed even when the injections were separated temporally and spatially suggests that the underlying mechanism is more complicated than mere creation of a WGA-HRP/CTB-HRP complex that cannot be taken up and transported by the sciatic nerve.