Topographic organization and possible function of the posterior optic tubercles in the brain of the desert locust Schistocerca gregaria
Topographic organization and possible function of the posterior optic tubercles in the brain of the desert locust Schistocerca gregaria
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DOI：
10.1002/cne.23736
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发表时间：
2015-08-01
影响因子：
2.5
通讯作者：
Homberg, Uwe
中科院分区：
文献类型：
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作者：
Beetz, M. Jerome;el Jundi, Basil;Homberg, Uwe
迁徙的沙漠蝗虫，Schistocerca gregaria，能够利用天空偏振模式进行导航。它们用复眼中专门的背缘区域来检测偏振光。经过多级处理后，极化信号被转移到中央复合体，这是一个涉及运动控制的跨中线脑区。极化敏感的切向神经元（TB-神经元）的原脑桥，中央复合体的一部分，引起的地形安排的首选极化角的桥梁，这表明中央复合体作为一个内部的天空指南针。TB-神经元连接前脑桥与两个相邻的脑区，后视结节。为了进一步分析中央复合物的极化组织，我们研究了TB-神经元的数量和形态以及这些神经元中三种神经活性物质的存在和共定位。三重免疫染色与抗血清对Diploptera punctata allatostatin（Dip-AST），曼陀罗allatotropin（Mas-AT），血清素（5 HT）提出了在同一宿主物种揭示了三个空间上不同的TB-神经元簇，每个由10个神经元每半球：簇1和3显示Dip-AST/5 HT免疫染色，而簇2显示Dip-AST/Mas-AT免疫染色。根据分支模式可区分TB神经元的五种亚型。对应于前脑桥中的分支域，神经元侵入后视结节内不同但重叠的层。同样，连接两个半球结节的神经元也针对这些神经柱的不同层。从这些数据中，我们提出了一个神经元电路，可能适合于稳定的内部天空罗盘在中央复杂的蝗虫。J. Comp.神经元523：1589-1607，2015. (c)2015 Wiley Periodicals，Inc.
Migrating desert locusts, Schistocerca gregaria, are able to use the skylight polarization pattern for navigation. They detect polarized light with a specialized dorsal rim area in their compound eye. After multistage processing, polarization signals are transferred to the central complex, a midline-spanning brain area involved in locomotor control. Polarization-sensitive tangential neurons (TB-neurons) of the protocerebral bridge, a part of the central complex, give rise to a topographic arrangement of preferred polarization angles in the bridge, suggesting that the central complex acts as an internal sky compass. TB-neurons connect the protocerebral bridge with two adjacent brain areas, the posterior optic tubercles. To analyze the polarotopic organization of the central complex further, we investigated the number and morphologies of TB-neurons and the presence and colocalization of three neuroactive substances in these neurons. Triple immunostaining with antisera against Diploptera punctata allatostatin (Dip-AST), Manduca sexta allatotropin (Mas-AT), and serotonin (5HT) raised in the same host species revealed three spatially distinct TB-neuron clusters, each consisting of 10 neurons per hemisphere: cluster 1 and 3 showed Dip-AST/5HT immunostaining, whereas cluster 2 showed Dip-AST/Mas-AT immunostaining. Five subtypes of TB-neuron could be distinguished based on ramification patterns. Corresponding to ramification domains in the protocerebral bridge, the neurons invaded distinct but overlapping layers within the posterior optic tubercle. Similarly, neurons interconnecting the tubercles of the two hemispheres also targeted distinct layers of these neuropils. From these data we propose a neuronal circuit that may be suited to stabilize the internal sky compass in the central complex of the locust. J. Comp. Neurol. 523:1589-1607, 2015. (c) 2015 Wiley Periodicals, Inc.