Zhuo H, Lewin A C, Phillips E T, Sinclair C M, Helke C J
Department of Pharmacology, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA.
Neuroscience. 1995 May;66(1):175-87. doi: 10.1016/0306-4522(94)00561-i.
Previous work showed that axotomy-induced deafferentation of the placode-derived visceral afferent neurons of the nodose ganglion altered their expression of some neuropeptides and tyrosine hydroxylase. The present studies were designed to selectively evaluate the loss of axonal transport on the numbers of vasoactive intestinal polypeptide, tyrosine hydroxylase, and calcitonin gene-related peptide mRNA-containing and immunoreactive neurons in the nodose ganglion of the adult rat. Vinblastine (0.15 mM) application to the cervical vagus nerve was used to block axonal transport between ganglionic perikarya and peripheral targets. In situ hybridization histochemistry with 35S-labeled oligonucleotide probes was used to both quantify the number of mRNA-containing neurons and to assess the density of mRNA expression per neuron, and immunocytochemistry was used to visualize the number of immunoreactive neurons. The efficacy of vinblastine to inhibit axonal transport was verified by evaluating the build-up of calcitonin gene-related peptide immunoreactive in the vagus nerve immediately rostral to the site of drug application. The absence of vinblastine-induced neuronal damage was verified by the relative absence of degenerating nerves in the vagus nerve caudal to the site of drug application. Vinblastine treatment of the vagus nerve increased the numbers of vasoactive intestinal peptide mRNA-containing neurons and vasoactive intestinal peptide-immunoreactive neurons in the nodose ganglion at three, seven and 14 days, and increased the numbers of calcitonin gene-related peptide mRNA-containing and calcitonin gene-related peptide-immunoreactive neurons in the nodose ganglion at one, three and seven days. The average labeling density of vasoactive intestinal peptide mRNA-containing neurons was also increased following vinblastine treatment. Vinblastine treatment of the cervical vagus nerve, however, led to the appearance of low-labeling density calcitonin gene-related peptide mRNA-neurons and resulted in reduction of the average labeling density for calcitonin gene-related peptide mRNA-containing neurons. In contrast, application of vinblastine to the cervical vagus nerve, decreased the number of tyrosine hydroxylase mRNA-containing and tyrosine hydroxylase-immunoreactive neurons in the nodose ganglion. In summary, inhibition of the axoplasmic transport between the periphery and the visceral sensory perikarya appeared to alter vasoactive intestinal peptide, calcitonin gene-related peptide, and tyrosine hydroxylase expression and content in visceral sensory neurons of the nodose ganglion. These data suggest the presence of an axonally transported influence on the regulation of neuropeptide and neurotransmitter enzyme synthesis in mature placode-derived visceral sensory neurons.
先前的研究表明，切断轴突导致结状神经节中由基板衍生的内脏传入神经元传入神经阻滞，改变了它们某些神经肽和酪氨酸羟化酶的表达。本研究旨在选择性评估轴突运输缺失对成年大鼠结状神经节中含血管活性肠肽、酪氨酸羟化酶和降钙素基因相关肽mRNA及免疫反应性神经元数量的影响。将长春碱（0.15 mM）应用于颈迷走神经，以阻断神经节神经元胞体与外周靶标之间的轴突运输。使用35S标记的寡核苷酸探针进行原位杂交组织化学，以量化含mRNA神经元的数量并评估每个神经元的mRNA表达密度，免疫细胞化学则用于观察免疫反应性神经元的数量。通过评估在药物应用部位紧邻头侧的迷走神经中降钙素基因相关肽免疫反应性的积累，验证长春碱抑制轴突运输的效果。通过药物应用部位尾侧的迷走神经中退变神经相对较少，验证长春碱未诱导神经元损伤。长春碱处理迷走神经后，在第3、7和14天增加了结状神经节中含血管活性肠肽mRNA神经元和血管活性肠肽免疫反应性神经元的数量，在第1、3和7天增加了结状神经节中含降钙素基因相关肽mRNA和降钙素基因相关肽免疫反应性神经元的数量。长春碱处理后，含血管活性肠肽mRNA神经元的平均标记密度也增加。然而，长春碱处理颈迷走神经导致出现低标记密度的降钙素基因相关肽mRNA神经元，并导致含降钙素基因相关肽mRNA神经元的平均标记密度降低。相反，将长春碱应用于颈迷走神经，减少了结状神经节中含酪氨酸羟化酶mRNA和酪氨酸羟化酶免疫反应性神经元的数量。总之，外周与内脏感觉神经元胞体之间轴浆运输的抑制似乎改变了结状神经节内脏感觉神经元中血管活性肠肽、降钙素基因相关肽和酪氨酸羟化酶的表达及含量。这些数据表明，在成熟的基板衍生内脏感觉神经元中，存在一种轴突运输对神经肽和神经递质酶合成调节的影响。
