Retinotopic organization of small-field-target-detecting neurons in the insect visual system
Retinotopic organization of small-field-target-detecting neurons in the insect visual system
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DOI：
10.1016/j.cub.2007.02.039
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发表时间：
2007-04-03
期刊：
影响因子：
9.2
通讯作者：
O'Carroll, David C.
中科院分区：
文献类型：
--
作者：
Barnett, Paul D.;Nordstrom, Karin;O'Carroll, David C.
背景资料：尽管有小的大脑和相对低分辨率的复眼，许多苍蝇物种经常从事精确控制的特技飞行的同类追求。最近的调查高阶处理在飞行视觉系统中已经揭示了一类神经元，创造了小目标运动检测器（STMD），能够鲁棒地响应目标运动对运动的背景杂波。尽管有限的空间敏锐度在昆虫的眼睛，这些神经元显示精致的灵敏度小targets.Results：我们记录胞内从形态学上确定的柱状神经元的叶复合的食蚜蝇Eristalis tenax。我们发现，这些柱状神经元与精致的小感受野，像他们的大领域的同行最近描述的男性和女性苍蝇，有一个极端的选择性运动的小目标。在这样做的过程中，我们提供了第一个生理特性的小领域的神经元在雌性苍蝇。这些retinotopically组织的柱状神经元包括方向选择性和nondirection-selective类覆盖大面积的visualspaces.Conclusions：视网膜定位安排小叶柱状神经元敏感的小目标的运动，使这些神经元作为重要的前体在本地处理的目标运动强有力的情况下。此外，在移动背景杂波的存在下，具有这样小的感受野的STMD对小目标的运动的持续响应进一步限制了其小目标调谐的潜在机制。
Background: Despite having tiny brains and relatively low-resolution compound eyes, many fly species frequently engage in precisely controlled aerobatic pursuits of conspecifics. Recent investigations into high-order processing in the fly visual system have revealed a class of neurons, coined small-target-motion detectors (STMDs), capable of responding robustly to target motion against the motion of background clutter. Despite limited spatial acuity in the insect eye, these neurons display exquisite sensitivity to small targets.Results: We recorded intracellularly from morphologically identified columnar neurons in the lobula complex of the hoverfly Eristalis tenax. We show that these columnar neurons with exquisitely small receptive fields, like their large-field counterparts recently described from both male and female flies, have an extreme selectivity for the motion of small targets. In doing so, we provide the first physiological characterization of small-field neurons in female flies. These retinotopically organized columnar neurons include both direction-selective and nondirection-selective classes covering a large area of visual space.Conclusions: The retinotopic arrangement of lobula columnar neurons sensitive to the motion of small targets makes a strong case for these neurons as important precursors in the local processing of target motion. Furthermore, the continued response of STMDs with such small receptive fields to the motion of small targets in the presence of moving background clutter places further constraints on the potential mechanisms underlying their small-target tuning.