Intersegmental coordination:: influence of a single walking leg on the neighboring segments in the stick insect walking system
Intersegmental coordination:: influence of a single walking leg on the neighboring segments in the stick insect walking system
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DOI：
10.1152/jn.00291.2007
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发表时间：
2007-09-01
影响因子：
2.5
通讯作者：
Bueschges, Ansgar
中科院分区：
文献类型：
--
作者：
Borgmann, Anke;Scharstein, Hans;Bueschges, Ansgar
步行的一个关键要素是多个肢体的协调相互作用，以实现适应环境的稳定运动模式。我们研究了杆状昆虫(Carausius Morosus)行走的节间协调性，考察了一条步行腿对另一侧神经节的运动神经活动的影响，以及这种影响是否随着行走方向的变化而变化。我们使用了减少的单腿步行准备，只有一条完整的前腿、中腿或后腿。完整的腿在跑步机上进行步进运动，从而向另一侧神经节提供有关其步进的节间信号。在所有其他节段同时记录髋部运动神经元的活动。任何一条腿在任何一个行走方向上的步进序列都伴随着所有其他节段的髋部运动神经元(MN)活动的增加，这种活动主要是受调制的，并且与行走腿的站姿略有同步。此外，前腿向前走，后腿向后走，在较小程度上引起了间胸髋部MN的交替活动。中腿向前和向后踏步不能引起其他半神经节中髋部MN的交替活动，表明中腿踏步的影响与前后腿向前和向后踏步的影响有本质的不同。我们的结果表明，在昆虫行走系统中，各个节段的节间影响不同，因此在节段行走模式生成器链中不能被视为相似的。讨论了当前关于节段间协调的概念的后果。
A key element of walking is the coordinated interplay of multiple limbs to achieve a stable locomotor pattern that is adapted to the environment. We investigated intersegmental coordination of walking in the stick insect, Carausius morosus by examining the influence a single stepping leg has on the motoneural activity of the other hemiganglia, and whether this influence changes with the walking direction. We used a reduced single leg walking preparation with only one intact front, middle, or hind leg. The intact leg performed stepping movements on a treadmill, thus providing intersegmental signals about its stepping to the other hemiganglia. The activity of coxal motoneurons was simultaneously recorded extracellularly in all other segments. Stepping sequences of any given single leg in either walking direction were accompanied by an increase in coxal motoneuron ( MN) activity of all other segments, which was mostly modulated and slightly in phase with stance of the walking leg. In addition, forward stepping of the front leg and, to a lesser extent, backward stepping of the hind leg elicited alternating activity in mesothoracic coxal MNs. Forward and backward stepping of the middle leg did not elicit alternating activity in coxal MNs in any other hemiganglia, indicating that the influence of middle leg stepping is qualitatively different from that of forward front and backward hind leg stepping. Our results indicate that in an insect walking system individual segments differ with respect to their intersegmental influences and thus cannot be treated as similar within the chain of segmental walking pattern generators. Consequences for the current concepts on intersegmental coordination are discussed.