Bekoff A, Nusbaum M P, Sabichi A L, Clifford M
J Neurosci. 1987 Aug;7(8):2320-30.
Previous work has shown that the neural circuits underlying the leg movements of walking and hatching coexist in post-hatching chicks (Bekoff and Kauer, 1984). In the present study, quantitative analysis of leg EMGs shows that there are some similarities, but also significant differences, in the motor output patterns of walking and hatching. This study examines the effect of removing sensory feedback from the legs on the production of the distinctive leg motor patterns. The temporal characteristics and interlimb coordination of hatching and walking are little affected. However, major changes in intralimb motor output patterns are seen when compared to records from normal chicks. These changes fall into one of 2 categories. Some parameters show similar changes in both behaviors after deafferentation (e.g., increases in flexor burst durations and cycle period). This suggests that certain features of sensory input from the legs normally modulate the hatching and walking pattern-generating circuitry in similar ways. Other parameters show convergence. That is, these aspects of the 2 intralimb motor patterns become more similar to each other after removal of sensory input. This is consistent with the hypothesis that some feature of sensory input from the legs normally modulates one set of multiuse intralimb circuitry to produce different output patterns. In general, the walking pattern becomes more like hatching after deafferentation, rather than the reverse, which suggests that the hatching pattern is a more basic one. The maintenance of some residual differences in intralimb motor patterns after leg deafferentation suggests that other sources of modulation must also be involved, or that there are some additional elements of circuitry that are called into play during the normal production of walking and hatching.
先前的研究表明，行走和出壳时腿部运动所涉及的神经回路在雏鸡出壳后是共存的（贝科夫和考尔，1984年）。在本研究中，对腿部肌电图的定量分析表明，行走和出壳的运动输出模式存在一些相似之处，但也有显著差异。本研究考察了去除腿部感觉反馈对独特腿部运动模式产生的影响。出壳和行走的时间特征以及肢体间协调性受影响较小。然而，与正常雏鸡的记录相比，肢体内部运动输出模式出现了重大变化。这些变化可分为两类。一些参数在去传入神经后，两种行为中都出现了类似的变化（例如，屈肌爆发持续时间和周期增加）。这表明来自腿部的感觉输入的某些特征通常以类似的方式调节出壳和行走模式生成电路。其他参数则表现出趋同。也就是说，去除感觉输入后，这两种肢体内部运动模式的这些方面变得更加相似。这与以下假设一致，即来自腿部的感觉输入的某些特征通常调节一组多用途的肢体内部电路，以产生不同的输出模式。一般来说，去传入神经后，行走模式变得更像出壳模式，而不是相反，这表明出壳模式是更基本的模式。腿部去传入神经后，肢体内部运动模式仍存在一些残余差异，这表明还必须涉及其他调节来源，或者在正常的行走和出壳过程中，还有一些额外的电路元件被激活。
