Neural control and coordination of jumping in froghopper insects
Neural control and coordination of jumping in froghopper insects
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DOI：
10.1152/jn.00719.2006
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发表时间：
2007-01-01
影响因子：
2.5
通讯作者：
Burrows, Malcolm
中科院分区：
文献类型：
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作者：
Burrows, Malcolm
蛙鼠跳跃的推力是由胸部巨大的多节转子降肌和髋部较小的提肌产生的两条后腿快速、同步的凹陷产生的。一个三相运动模式在跳跃时激活这些肌肉。首先，提升阶段持续几百毫秒，在此期间，粗隆提肌运动神经元的峰值爆发将后腿移动到完全翘起的位置，从而在髋部和股骨之间形成机械锁。第二阶段是“竖起”阶段，持续几秒钟，其间转子抑制运动神经元以逐渐上升到50赫兹的频率连续放电，尽管后腿保持静止。提肌运动脉冲是零星的。第三，跳跃运动持续时间< 1ms，此时降阻器的尖峰突然停止，腿迅速下陷。这种模式可能在初始上升的速度和翘起阶段的持续时间上有所不同。来自两侧降肌的记录显示，它们的运动尖峰具有显著的同步性。在一个4.9秒长的尖峰期，所有174个尖峰都是同步的；在另一个27秒的连续尖峰期，1176个尖峰中只有一个是同步的。当一条后腿快速移动时，这些抑制尖峰是独立于另一条腿的。运动模式的这些特征以及运动神经元与两条后腿之间的耦合确保了有力的运动来推动快速跳跃。
The thrust for jumping in froghopper insects is produced by a rapid, synchronous depression of both hind legs generated by huge, multipartite trochanteral depressor muscles in the thorax and smaller levator muscles in the coxae. A three-phase motor pattern activates these muscles in jumping. First, a levation phase lasts a few hundred milliseconds, in which a burst of spikes in the trochanteral levator motor neurons moves the hind legs into their fully cocked position and thus engages a mechanical lock between a coxa and a femur. Second, a cocked phase lasts a few seconds, in which a trochanteral depressor motor neuron spikes continuously at a frequency gradually rising to 50 Hz, although the hind legs remain stationary. Levator motor spikes are sporadic. Third, the jump movement lasts < 1 ms, in which the spikes in the depressors stop abruptly and the legs rapidly depress. This pattern may vary in the speed of the initial levation and in the duration of the cocked phase. Recordings from the depressor muscles on both sides showed remarkable synchrony of their motor spikes. In one 4.9- long cocked phase all 174 spikes were synchronous and in another 27 s period of continuous spiking all but one of 1,176 spikes were synchronous. When a single hind leg moves rapidly, these depressor spikes are nevertheless independent of those of the other leg. These features of the motor pattern and the coupling between motor neurons to the two hind legs ensure powerful movements to propel rapid jumping.