University of California, Los Angeles, Department of Integrative Biology and Physiology, 610 Charles Young Drive East, Los Angeles, CA 90095-7239, USA.
University of California, Los Angeles, Department of Integrative Biology and Physiology, 610 Charles Young Drive East, Los Angeles, CA 90095-7239, USA; University of California, Los Angeles, Department of Biological Chemistry, Howard Hughes Medical Institute, David Geffen School of Medicine, Los Angeles, CA 90095, USA.
Cell Rep. 2020 Feb 18;30(7):2115-2124.e5. doi: 10.1016/j.celrep.2020.01.061.
The direction-selective T4/T5 cells innervate optic-flow processing projection neurons in the lobula plate of the fly that mediate the visual control of locomotion. In the lobula, visual projection neurons coordinate complex behavioral responses to visual features, however, the input circuitry and computations that bestow their feature-detecting properties are less clear. Here, we study a highly specialized small object motion detector, LC11, and demonstrate that its responses are suppressed by local background motion. We show that LC11 expresses GABA-A receptors that serve to sculpt responses to small objects but are not responsible for the rejection of background motion. Instead, LC11 is innervated by columnar T2 and T3 neurons that are themselves highly sensitive to small static or moving objects, insensitive to wide-field motion and, unlike T4/T5, respond to both ON and OFF luminance steps.
方向选择性 T4/T5 细胞支配着蝇类的外侧小叶板中的光流处理投射神经元，这些神经元介导着运动的视觉控制。在外侧小叶中，视觉投射神经元协调着对视觉特征的复杂行为反应，然而，赋予它们特征检测属性的输入电路和计算还不太清楚。在这里，我们研究了一种高度专业化的小物体运动探测器 LC11，并证明其反应受到局部背景运动的抑制。我们表明 LC11 表达 GABA-A 受体，这些受体有助于塑造对小物体的反应，但不负责拒绝背景运动。相反，LC11 由柱状 T2 和 T3 神经元支配，这些神经元本身对小的静态或运动物体高度敏感，对宽场运动不敏感，与 T4/T5 不同，它们对 ON 和 OFF 亮度阶跃都有反应。
