Ashwell Ken W S, Hardman Craig D, Paxinos George
Department of Anatomy, School of Medical Sciences, The University of New South Wales, New South Wales, Sydney 2052, Australia.
J Chem Neuroanat. 2006 Feb;31(2):81-107. doi: 10.1016/j.jchemneu.2005.08.007. Epub 2005 Sep 29.
We have examined the cyto- and chemoarchitecture of the trigeminal nuclei of two monotremes using Nissl staining, enzyme reactivity for cytochrome oxidase, immunoreactivity for calcium binding proteins and non-phosphorylated neurofilament (SMI-32 antibody) and lectin histochemistry (Griffonia simplicifolia isolectin B4). The principal trigeminal nucleus and the oralis and interpolaris spinal trigeminal nuclei were substantially larger in the platypus than in either the echidna or rat, but the caudalis subnucleus was similar in size in both monotremes and the rat. The numerical density of Nissl stained neurons was higher in the principal, oralis and interpolaris nuclei of the platypus relative to the echidna, but similar to that in the rat. Neuropil immunoreactivity for parvalbumin was particularly intense in the principal trigeminal, oralis and interpolaris subnuclei of the platypus, but the numerical density of parvalbumin immunoreactive neurons was not particularly high in these nuclei of the platypus. Neuropil immunoreactivity for calbindin and calretinin was relatively weak in both monotremes, although calretinin immunoreactive somata made up a large proportion of neurons in the principal, oralis and interpolaris subnuclei of the echidna. Distribution of calretinin immunoreactivity and Griffonia simplicifolia B4 isolectin reactivity suggested that the caudalis subnucleus of the echidna does not have a clearly defined gelatinosus region. Our findings indicate that the trigeminal nuclei of the echidna do not appear to be highly specialized, but that the principal, oralis and interpolaris subnuclei of the platypus trigeminal complex are highly differentiated, presumably for processing of tactile and electrosensory information from the bill.
我们使用尼氏染色、细胞色素氧化酶的酶活性、钙结合蛋白和非磷酸化神经丝（SMI-32抗体）的免疫反应性以及凝集素组织化学（西非单叶豆凝集素B4），研究了两种单孔目动物三叉神经核的细胞结构和化学结构。鸭嘴兽的主要三叉神经核以及三叉神经脊束核的口部和极间部比针鼹或大鼠的相应核团大得多，但尾侧亚核在两种单孔目动物和大鼠中的大小相似。相对于针鼹，鸭嘴兽主要、口部和极间核中尼氏染色神经元的数量密度更高，但与大鼠中的相似。在鸭嘴兽的主要三叉神经、口部和极间亚核中，小白蛋白的神经毡免疫反应性特别强烈，但在鸭嘴兽的这些核团中，小白蛋白免疫反应性神经元的数量密度并不特别高。在两种单孔目动物中，钙结合蛋白和钙视网膜蛋白的神经毡免疫反应性相对较弱，尽管在针鼹的主要、口部和极间亚核中，钙视网膜蛋白免疫反应性胞体占神经元的很大比例。钙视网膜蛋白免疫反应性和西非单叶豆B4凝集素反应性的分布表明，针鼹的尾侧亚核没有明确界定的胶状区。我们的研究结果表明，针鼹的三叉神经核似乎没有高度特化，但鸭嘴兽三叉神经复合体的主要、口部和极间亚核高度分化，可能用于处理来自喙的触觉和电感觉信息。
