Organization and neural connections of the anterior optic tubercle in the brain of the locust, Schistocerca gregaria
Organization and neural connections of the anterior optic tubercle in the brain of the locust, Schistocerca gregaria
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DOI：
10.1002/cne.10771
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发表时间：
2003-08-04
影响因子：
2.5
通讯作者：
Gebhardt, S
中科院分区：
文献类型：
--
作者：
Homberg, U;Hofer, S;Gebhardt, S
视前结节是昆虫脑内的一个小的神经瘤，是来自视叶的视觉中间神经元的主要目标。结节的功能作用尚不清楚，但最近来自蝗虫的证据表明可能参与偏振视觉。本研究探讨了刺槐前视结节的组织结构及其与其他脑区的联系。蝗虫的结节由上亚基和下亚基组成。这两个单位与视叶的髓质和小叶平行相连，与对侧结节平行相连，并与前大脑正中的外侧副叶平行相连。宽视场的跨髓神经元提供来自髓质的输入。髓质背缘是极化视觉通路的中继站，在髓质背缘有突起的神经元只投射到结节的下部。从小叶到上下单元的视觉输入来自地形不同的地层。结节最突出的输出目标是位于前大脑正中的外侧副叶。来自上部单元的神经元广泛地投射到外侧副叶，而来自下部单元的神经元集中投射到正中橄榄和外侧三角形。因此，视神经前结节的两个亚基是视神经叶到正中脑原的两条平行视觉通路的加工阶段。经由结节下部的通路似乎与偏振视觉有关。(C) 2003 Wiley-Liss, Inc。
The anterior optic tubercle is a small neuropil in the insect brain and a major target of visual interneurons from the optic lobe. The functional role of the tubercle is poorly understood, but recent evidence from locusts points to a possible involvement in polarization vision. The present study examines the organization of the anterior optic tubercle in the locust Schistocerca gregaria and its connections with other brain areas. The tubercle of the locust consists of an upper and a lower subunit. Both units are connected in parallel with the medulla and lobula of the optic lobe, with the contralateral tubercle, and with the lateral accessory lobe in the median protocerebrum. Wide-field transmedullary neurons provide input from the medulla. Neurons with processes in the dorsal rim of the medulla, a relay station in the polarization vision pathway, project exclusively to the lower unit of the tubercle. Visual input from the lobula to the upper and lower unit originates from topographically distinct strata. The most prominent output target of the tubercle is the lateral accessory lobe in the median protocerebrum. Neurons from the upper unit project widely in the lateral accessory lobe, whereas neurons from the lower unit have focused projections confined to the median olive and to the lateral triangle. The two subunits of the anterior optic tubercle are, therefore, processing stages in two parallel visual pathways from the optic lobe to the median protocerebrum. Pathways via the lower unit of the tubercle appear to be involved in polarization vision. (C) 2003 Wiley-Liss, Inc.