Optomotor response (eye movment) and avoidance responses (locomotor activity) of crabs Neohelice granulata for LP-lesioned, control lesioned and control crabs

When an animal rotates (whether it is an arthropod, a fish, a bird, or a human) a drift of the visual panorama occurs over its retina, termed optic flow. The image motion is stabilized by compensatory behaviors (driven by the movement of the eyes, head or the whole body depending on the animal) collectively termed optomotor response (OR). Dipteran lobula plate has been consistently linked with optic flow processing and the control of optomotor responses. Crabs have a neuropil similarly located and interconnected in the optic lobes, therefore referred to as a lobula plate also. Here we show that the crab’s lobula plate is required for normal optomotor response since the response was lost or severely impaired in animals whose lobula plate had been lesioned. The effect was behavior-specific, since avoidance responses to approaching visual stimuli were not affected. Crabs require simpler optic flow processing than flies (because they move slower and in 2D instead of 3D), consequently their ...当动物发生旋转时（无论其属于节肢动物、鱼类、鸟类还是人类），其视网膜上都会出现视觉全景的漂移现象，该现象被称为光流（optic flow）。机体可通过补偿行为稳定图像运动：这类行为由眼睛、头部或全身的运动驱动，具体驱动模式因动物种类而异，所有此类行为统称为视动反应（optomotor response, OR）。双翅目小叶板（Dipteran lobula plate）一直被证实与光流处理及视动反应的调控存在稳定关联。螃蟹的视叶（optic lobes）中存在位置相似且相互连接的神经纤维网（neuropil），因此同样被称为小叶板。本研究证实，螃蟹的小叶板是正常视动反应所必需的：当损毁螃蟹的小叶板后，其视动反应会完全消失或严重受损。该效应具有行为特异性，因为动物对逼近视觉刺激的回避反应并未受到影响。相较于果蝇，螃蟹的光流处理过程更为简单——这是因为螃蟹运动速度更慢，且仅在二维平面而非三维空间中移动，因此它们的……