Fluid dynamics and microscale chemical movement in the chemosensory appendages of the lobster, Homarus americanus
Fluid dynamics and microscale chemical movement in the chemosensory appendages of the lobster, Homarus americanus
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美洲白龙虾化学感应附属物的流体动力学和微观化学运动
DOI：
10.1093/chemse/16.6.663
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发表时间：
1991
期刊：
影响因子：
3.5
通讯作者：
G. Gerhardt
中科院分区：
文献类型：
--
作者：
P. Moore;J. Atema;G. Gerhardt
每个化学感觉结构都有一个围绕它的边界层，化学信号在接触感受器细胞之前必须通过这个边界层。该边界层内流体运动缓慢，气味运动以扩散为主。附面层的结构取决于外部流体速度和附体的形态。利用微化学电极的高速(10-200 Hz)电化学记录技术，定量研究了龙虾三种不同形态的化学感受器：外侧触角、内侧触角和行走腿在微尺度环境中的化学传递。气味示踪剂(多巴胺)的受控脉冲以三种不同的流速(0、3、6 cm/S)输送到三个附件。脉冲幅度随流速的增大而增大，表明边界层厚度随流速的增大而减小。在所有流速下，行走腿的脉冲幅度都大于外侧或内侧触角的脉冲幅度。此外，内侧触角的波幅大于外侧触角。脉冲幅度随流速的变化大于脉宽的变化。这些结果表明，脉冲幅度比脉冲持续时间更受边界层厚度的影响，并且受体结构的形态有助于确定到达受体细胞的信号的结构。这可能解释了为什么动物采取了减少边界层厚度的采样策略。
Every chemosensory structure has a boundary layer surrounding it through which chemical signals must pass before contacting receptor cells. Fluid motion in this boundary layer is slow and odor movement is mainly by diffusion. The boundary layer structure depends upon external fluid velocities and the morphology of the appendage. High-speed (10-200 Hz) electrochemical recordings from microchemical electrodes were used to quantify chemical transport in the microscale environment of three morphologically different chemosensory appendages of the lobster, Homarus americanus: lateral antennule, medial antennule and walking legs. Controlled pulses of the odor tracer (dopamine) were delivered to the three appendages at three different flow speeds (0, 3, 6 cm/s). The amplitudes of the pulses increased with increasing flow speed, indicating that boundary layer thickness decreased with increasing flow speed. Larger pulse amplitudes were measured in the walking legs than in the lateral or medial antennules at all flow speeds. In addition, larger amplitudes were recorded in the medial antennule than the lateral antennule. Changes in pulse amplitude with increasing flow speed were larger than changes in pulse duration. These results demonstrate that pulse amplitude is affected more than pulse duration by boundary layer thickness and that the morphology of the receptor strucure helps determine the structure of signals arriving at receptor cells. This may explain why animals have adopted sampling strategies that reduce boundary layer thickness.