Operation System of Insect Brain for Sophisticated Behavior

中国虎甲的幼虫是一种伏击猎人，体长15-22毫米，生活在地下的隧道里。它伏击猎物，在隧道的开口处保持头部水平。当猎物接近隧道时，幼虫跳起来咬住它。然而，当物体移动超过其跳跃范围(大约15毫米)时，幼虫很快就会退回到隧道深处。这些反应是由六对茎中的两对介导的。幼虫如何使用如此简单的视觉系统来判断狩猎范围？行为观察证实了双目视觉对距离的估计，即当通过棱镜或狭窄窗口在靠近幼虫的地方形成虚拟图像时，幼虫跳向正常狩猎范围以外的物体。单目视觉距离估计也得到了行为学实验的证实。图像在视网膜中的深度似乎在距离估计中起到了作用，因为有一个有趣的…的幼虫当将凹透镜置于其头顶上方时，当其他茎被遮挡时，更多的功能茎改变了对非常远的物体的反应，从逃逸到跳跃。延髓神经元(二级视觉中间神经元)的细胞内反应表明，距离敏感确实发生在大脑的外围部分。比较了延髓神经元对10 mm和50 mm高度运动物体的反应模式。大多数神经元对10 mm和50 mm高度移动的物体有相同的放电模式。然而，一些神经元表现出对距离敏感的反应，只有在两个高度中的任何一个移动物体时，尖峰放电都会增加。这种距离敏感性仍然存在于单柄幼虫中，四个茎中有三个被闭塞。上述行为和电生理结果表明。我们得出结论，关于虎甲幼虫狩猎范围的视觉信息是由图像清晰度的空间模式在外围提取的，可能是通过双目视觉集中提取的。较少

The larva of the tiger beetle Cicindela chinensis is an ambushing hunter with a body length of 15-22 mm, that lives in a tunnel in the ground. It ambushes prey, keeping its head horizontal at the opening of the tunnel. When prey approaches the tunnel, the larva jumps to snap at it. When an object moves beyond its jumping range (approximately 15 mm), however, the larva quickly withdraws deep into the tunnel. These responses are mediated by two of six pairs of stemmata. How does the larva judge the hunting range using such a simple visual system? Range estimation by binocular vision was confirmed by behavioral observations, in which larvae jumped towards objects beyond the normal hunting range when virtual images of such distant objects were formed close to the larva by prisms or a narrow window. Range estimation by monocular vision was also confirmed by behavioral experiments. The depth of the image in the retina appears to have a role in distance estimation because a larva with one fun … More ctional stemma, other stemmata being occluded, changed its response to a very distant object from escape to jump when a concave lens was placed above its head.Intracellular responses of medulla neurons (second order visual interneurons) showed that distance sensitivities really occurred in the peripheral part of the brain. Response patterns of medulla neurons to moving objects at heights of 10 mm and 50 mm were compared. The majority of neurons responded to objects moving at heights of 10 mm and 50 mm with the same discharge pattern. A few neurons, however, showed distance sensitivities responding with an increase of spike discharges to moving objects only at either of the two heights. Such distance sensitivities still remained in one-stemma larvae, three of the four stemmata being occluded.Above mentioned behavioral and electrophysiological results suggested. We conclude that visual information about hunting range in the tiger beetle larva is extracted peripherally by the spatial pattern of image clarity, and probably centrally by binocular vision. Less