International Research Fellowship Program: Flight and Motion Perception in Nocturnal Bees

[4060 . 06]国际研究奖学金计划使美国科学家和工程师能够到国外进行3至24个月的研究。该计划的奖励为联合研究提供了机会，并利用独特或互补的设施、专业知识和国外的实验条件。该奖项将支持Jamie C. Theobald博士与瑞典隆德大学的Eric J. Warrant博士以及位于巴拿马巴罗科罗拉多岛的史密森尼热带研究所开展为期22个月的研究。这个项目研究动物在黑暗中保持可靠视力的神经机制。大翅蜂是完全夜间活动的新热带蜜蜂，它们在比星光暗20倍的森林中导航。蜜蜂很少在夜间活动，因为它们有对视复眼，这种设计不适合弱光，因此几乎没有空间来改善视力。它们的视网膜吸收被光子噪声量子现象破坏的信号。这项研究验证了一种假设，即巨鳍象依靠神经求和在黑暗中看得很清楚。行为和神经生物学实验揭示了感觉输入和肌肉输出之间的信号处理，并建立了数学模型来分析描述它。行为的特点是拍摄蜜蜂在蜂巢周围的飞行，以将光照水平与飞行敏捷性联系起来。神经处理是通过显示视觉场景，同时从视网膜细胞和检测飞行过程中自我运动的脑细胞中进行电记录来检查的。我们的期望是，巨眼象利用神经求和在黑暗中飞行和导航，这表现在运动探测神经元的低最佳空间和时间频率，以及在黑暗中牺牲尖锐动作的飞行。

0401906TheobaldThe International Research Fellowship Program enables U.S. scientists and engineers to conduct three to twenty-four months of research abroad. The program's awards provide opportunities for joint research, and the use of unique or complementary facilities, expertise and experimental conditions abroad.This award will support a twenty-two-month research fellowship by Dr. Jamie C. Theobald to work with Dr. Eric J. Warrant at Lund University in Sweden and at the Smithsonian Tropical Research Institute on Barro Colorado Island in Panama. This project examines the neural mechanisms through which animals maintain reliable vision in darkness. Megalopta genalis are fully nocturnal neotropical bees which visually navigate through forests 20 times dimmer than starlight. Night activity is rare among bees because they possess apposition compound eyes, a design unsuited to low light, and leaving little room to improve vision optically. Their retinas absorb signals compromised by the quantum phenomenon of photon noise. This research tests the hypothesis that Megalopta rely on neural summation to see well in the dark. Behavioral and neurobiological experiments reveal the signal processing between sensory input and muscular output, and produce mathematical models to describe it analytically. Behavior is characterized by filming bee flight around a nest to correlate light level with flight agility. Neural processing is examined by displaying visual scenes while electrically recording from retinal cells, and brain cells that detect self-motion during flight. The expectation is that Megalopta uses neural summation to fly and navigate in darkness which manifests in low optimum spatial and temporal frequencies in motion-detecting neurons, and flight that sacrifices sharp maneuvers in the dark.