Douglass J K, Strausfeld N J
Arizona Research Laboratories, Division of Neurobiology, University of Arizona, Tucson 85721, USA.
J Comp Neurol. 1998 Jun 22;396(1):84-104.
In dipteran insects, the lobula plate neuropil provides a major efferent supply to the premotor descending neurons that control stabilized flight. The lobula plate itself is supplied by two major parallel retinotopic pathways from the medulla: small-field, magnocellular afferents that are implicated in achromatic motion processing and Y cells that connect the medulla with both the lobula plate and the lobula. A third pathway from the medulla involves transmedullary (Tm) neurons, which provide inputs to palisades of small-field neurons in the lobula. Although, in their passage to the brain, many output neurons from the lobula plate are separated physically from their counterparts in the lobula, there is an additional class of lobula complex output neurons. This group is composed of retinotopic lobula plate-lobula (LPL) and lobula-lobula plate (LLP) cells, each of which has dendrites in both the lobula and the lobula plate. The present account describes the anatomy and physiology of exemplars of LPL and LLP neurons, a wide-field tangential neuron that is intrinsic to the lobula complex, and representatives of the Tm- and Y-cell pathways. We demonstrate novel features of the lobula plate, which previously has been known as a motion-collating neuropil, and now also can be recognized as supporting direction- or nondirection-specific responses to local motion, encoding of contrast frequency, and processing of local structural features of the visual panorama.
在双翅目昆虫中，小叶板神经纤维网为控制稳定飞行的运动前下行神经元提供主要的传出神经支配。小叶板本身由来自髓质的两条主要平行视网膜拓扑通路供应：参与消色差运动处理的小视野大细胞传入神经，以及将髓质与小叶板和小叶相连的Y细胞。来自髓质的第三条通路涉及跨髓质（Tm）神经元，它们为小叶中小视野神经元的栅栏提供输入。尽管在通向大脑的过程中，小叶板的许多输出神经元在物理上与小叶中的对应神经元分离，但还有另一类小叶复合体输出神经元。这一组由视网膜拓扑小叶板 - 小叶（LPL）和小叶 - 小叶板（LLP）细胞组成，每个细胞在小叶和小叶板中都有树突。本报告描述了LPL和LLP神经元的实例、小叶复合体固有的宽视野切向神经元以及Tm和Y细胞通路代表的解剖结构和生理学。我们展示了小叶板的新特征，小叶板以前被认为是一个运动整合神经纤维网，现在也可以被认为支持对局部运动的方向特异性或非方向特异性反应、对比度频率编码以及视觉全景局部结构特征的处理。
