Berkowitz A, Laurent G
Division of Biology, California Institute of Technology, Pasadena, California 91125, USA.
J Neurosci. 1996 Dec 15;16(24):8067-78. doi: 10.1523/JNEUROSCI.16-24-08067.1996.
This study demonstrates that the thoracic and abdominal nervous system of locusts is sufficient to mediate several site-specific and distinct grooming leg movements. Locusts can use a hindleg or middle leg to groom at least four ipsilateral thoracic and abdominal sites, without input from the brain, subesophageal ganglion, or prothoracic ganglion. The hindleg is used to groom the posterior abdomen, the ventral or posterior hindleg coxa, and the ear; the middle leg is used to groom the anterior hindleg coxa. Grooming movements are often rhythmic and display site-specific intralimb coordination patterns. During grooming of the posterior abdomen or ventral hindleg coxa, for example, hindleg tibial extension occurs nearly simultaneously with femur elevation, in contrast with locust hindleg movements during walking. Electromyographic (EMG) recordings during these movements show that rhythmic bursts of tibial extensor activity occur nearly in-phase with those of trochanteral levators, in contrast to hindleg EMGs during walking. During grooming of the ear, hindleg tibial extension/flexion and tibial extensor/flexor muscle bursts can occur independently of the femur elevation/depression and trochanteral levator/depressor muscle bursts, suggesting that the neural modules controlling tibial and femoral movements can be uncoupled during this behavior. Tibial extension can occur before, or even in the absence of, tibial extensor muscle activity, suggesting that spring-like properties of the leg and energy transfer from femur motion may play important roles in such leg movements. Adjacent legs sometime show coordinated femur movement during grooming with one hindleg, suggesting that grooming may also involve interlimb coordination.
本研究表明，蝗虫的胸腹部神经系统足以介导几种特定部位且不同的梳理腿部运动。蝗虫可以使用后足或中足来梳理至少四个同侧的胸腹部部位，而无需来自脑、咽下神经节或前胸神经节的输入。后足用于梳理腹部后部、后足基节腹面或背面以及耳朵；中足用于梳理后足基节前部。梳理动作通常是有节奏的，并表现出特定部位的肢体内部协调模式。例如，在梳理腹部后部或后足基节腹面时，后足胫节伸展几乎与股骨抬起同时发生，这与蝗虫行走时的后足运动不同。这些运动期间的肌电图（EMG）记录表明，胫节伸肌活动的有节奏爆发几乎与转节提肌的爆发同步，这与行走时的后足肌电图不同。在梳理耳朵时，后足胫节伸展/弯曲以及胫节伸肌/屈肌的爆发可以独立于股骨抬起/下降以及转节提肌/降肌的爆发而发生，这表明控制胫节和股骨运动的神经模块在这种行为中可以解耦。胫节伸展可以在胫节伸肌活动之前甚至在没有胫节伸肌活动的情况下发生，这表明腿部的弹簧状特性以及来自股骨运动的能量传递可能在这种腿部运动中起重要作用。相邻的腿在与一只后足一起梳理时有时会表现出协调的股骨运动，这表明梳理可能还涉及肢体间的协调。
