Nahm I, Shin T, Watanabe H, Masuko S
Department of Otolaryngology, Saga Medical School, Japan.
Eur Arch Otorhinolaryngol. 1992;249(7):385-8. doi: 10.1007/BF00192259.
The recurrent laryngeal nerve (RLN) consists of various motor, sensory and autonomic nerve fibers, although it has not been established whether different neuronal types exhibit a similar ability to regenerate. To address this question, freezing was used to injure the cat RLN fibers and the presence or absence of immunoreactivity for neuropeptides or transmitter-synthesizing enzymes was then examined as a marker to classify the fibers. In the control RLN, calcitonin gene-related peptide-immunoreactive (CGRP-IR) fibers were the highest in number and were distributed throughout the nerve fascicles. The number of substance P-immunoreactive (SP-IR) fibers was about 40% that of CGRP-IR fibers, while a portion of CGRP-IR fibers was found to contain SP immunoreactivity. Relatively low numbers of tyrosine hydroxylase-immunoreactive (TH-IR) and neuropeptide Y (NPY-IR) nerve fibers were seen which tended to form clusters. The distribution pattern of NPY-IR fibers was very similar to that of TH-IR fibers. In the regenerating RLN 1 week after the freezing injury, the fastest growing axons were CGRP-IR, while the regenerating rates of SP-IR, TH-IR and NPY-IR fibers were slower than that of CGRP-IR fibers. These results suggest that the ability for neurite regeneration varies among neuron types and that CGRP-IR fibers possess the most rapid ability to regenerate.
喉返神经（RLN）由多种运动、感觉和自主神经纤维组成，尽管不同神经元类型是否具有相似的再生能力尚未确定。为了解决这个问题，采用冷冻法损伤猫的RLN纤维，然后检测神经肽或递质合成酶的免疫反应性的有无，以此作为纤维分类的标志物。在对照RLN中，降钙素基因相关肽免疫反应性（CGRP-IR）纤维数量最多，分布于整个神经束。P物质免疫反应性（SP-IR）纤维的数量约为CGRP-IR纤维的40%，同时发现一部分CGRP-IR纤维含有SP免疫反应性。可见相对较少数量的酪氨酸羟化酶免疫反应性（TH-IR）和神经肽Y（NPY-IR）神经纤维，它们倾向于形成簇状。NPY-IR纤维的分布模式与TH-IR纤维非常相似。在冷冻损伤后1周的再生RLN中，生长最快的轴突是CGRP-IR，而SP-IR、TH-IR和NPY-IR纤维的再生速度比CGRP-IR纤维慢。这些结果表明，神经突再生能力在不同神经元类型中存在差异，且CGRP-IR纤维具有最快的再生能力。
