Rivera Leni R, Thacker Michelle, Furness John B
Department of Anatomy & Cell Biology and Centre for Neuroscience, University of Melbourne, Parkville, Victoria 3010, Australia.
Cell Tissue Res. 2009 Mar;335(3):529-38. doi: 10.1007/s00441-008-0732-3. Epub 2008 Dec 12.
Previous studies have demonstrated that neurofilament proteins are expressed by type II neurons in the enteric plexuses of a range of species from mouse to human. However, two previous studies have failed to reveal this association in the guinea-pig. Furthermore, immunohistochemistry for neurofilaments has revealed neurons with a single axon and spiny dendrites in human and pig but this morphology has not been described in the guinea-pig or other species. We have used antibodies against high- and medium-weight neurofilament proteins (NF-H and NF-M) to re-examine enteric neurons in the guinea-pig. NF-H immunoreactivity occurred in all type II neurons (identified by their IB4 binding) but these neurons were never NF-M-immunoreactive. On the other hand, 17% of myenteric neurons expressed NF-M. Many of these were uni-axonal neurons with spiny dendrites and nitric oxide synthase (NOS) immunoreactivity. NOS immunoreactivity occurred in surface expansions of the cytoplasm that did not contain neurofilament immunoreactivity. Thus, because of their NOS immunoreactivity, spiny neurons had the appearance of type I neurons. This indicates that the apparent morphologies and the morphological classifications of these neurons are dependent on the methods used to reveal them. We conclude that spiny type I NOS-immunoreactive neurons have similar morphologies in human and guinea-pig and that many of these are inhibitory motor neurons. Both type II and neuropeptide-Y-immunoreactive neurons in the submucosal ganglia exhibit NF-H immunoreactivity. NF-M has been observed in nerve fibres, but not in nerve cell bodies, in the submucosa.
先前的研究表明，从小鼠到人类等一系列物种的肠神经丛中的II型神经元会表达神经丝蛋白。然而，之前的两项研究未能在豚鼠中发现这种关联。此外，神经丝的免疫组织化学显示，人类和猪的神经元具有单个轴突和棘状树突，但这种形态在豚鼠或其他物种中尚未被描述。我们使用针对高分子量和中分子量神经丝蛋白（NF-H和NF-M）的抗体，重新检查了豚鼠的肠神经元。NF-H免疫反应出现在所有II型神经元中（通过它们与IB4的结合来识别），但这些神经元从未有NF-M免疫反应。另一方面，17%的肌间神经元表达NF-M。其中许多是具有棘状树突和一氧化氮合酶（NOS）免疫反应的单轴突神经元。NOS免疫反应出现在细胞质的表面延伸部分，这些部分不含有神经丝免疫反应。因此，由于它们的NOS免疫反应，棘状神经元具有I型神经元的外观。这表明这些神经元的表观形态和形态学分类取决于用于揭示它们的方法。我们得出结论，棘状I型NOS免疫反应性神经元在人类和豚鼠中具有相似的形态，并且其中许多是抑制性运动神经元。黏膜下神经节中的II型和神经肽Y免疫反应性神经元均表现出NF-H免疫反应。在黏膜下层的神经纤维中观察到了NF-M，但在神经细胞体中未观察到。
