Loesel Rudi, Nässel Dick R, Strausfeld Nicholas J
Arizona Research Laboratories, Division of Neurobiology, University of Arizona, 611 Gould-Simpson, Tucson, AZ 85721, USA.
Arthropod Struct Dev. 2002 Sep;31(1):77-91. doi: 10.1016/S1467-8039(02)00017-8.
Most insects possess an assemblage of midline neuropils in their protocerebrum called the central complex. Recent studies have identified comparable assemblages in the malacostracan protocerebrum. Studies of Drosophila melanogaster locomotory mutants suggest that in insects one role for the central complex might be to orchestrate limb actions. This is anecdotally supported by comparisons amongst insects suggesting that elaboration of central complex architecture correlates with complexity of limb motor repertoires. The present account describes immunocytochemical and neuroanatomical observations that reveal common design principles amongst midline neuropils in four arthropod clades, the hexapods, crustaceans, chilopods, and chelicerates and the absence of midline neuropils in diplopods. The chilopod midline neuropil, which is columnar and stratified and lacks chiasmal axons to the dorsal protocerebrum or connections to discrete satellite regions, may represent the plesiomorphous condition. The complete absence of a midline neuropil in diplopods supports previous neuroanatomical studies suggesting that the 'Myriapoda' are an artificial paraphyletic group. The columnar and layered arcuate midline neuropils of chelicerates are compared with columnar and layered midline neuropils of chilopods. No midline neuropil has been identified in a lophotrochozoan outgroup, the Polychaeta.
大多数昆虫在其原脑中有一组被称为中央复合体的中线神经纤维网。最近的研究在软甲亚纲动物的原脑中发现了类似的结构。对黑腹果蝇运动突变体的研究表明，在昆虫中，中央复合体的一个作用可能是协调肢体动作。昆虫之间的比较从侧面支持了这一点，即中央复合体结构的精细化与肢体运动技能的复杂性相关。本报告描述了免疫细胞化学和神经解剖学观察结果，这些结果揭示了四个节肢动物类群（六足动物、甲壳类动物、唇足类动物和螯肢动物）中线神经纤维网之间的共同设计原则，以及倍足纲动物中不存在中线神经纤维网的情况。唇足纲动物的中线神经纤维网呈柱状且分层，缺乏通向背侧原脑的交叉轴突或与离散卫星区域的连接，可能代表了原始状态。倍足纲动物完全没有中线神经纤维网，这支持了先前的神经解剖学研究，即“多足纲”是一个人为的并系群。将螯肢动物的柱状和分层的弓形中线神经纤维网与唇足纲动物的柱状和分层的中线神经纤维网进行了比较。在一个触手冠动物外类群多毛纲动物中未发现中线神经纤维网。
