Oscillatory properties of the central pattern generator for locomotion in neonatal rats.
Oscillatory properties of the central pattern generator for locomotion in neonatal rats.
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新生大鼠运动的中央模式发生器的振荡特性。
DOI：
10.1152/jn.1993.70.2.803
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发表时间：
1993
影响因子：
2.5
通讯作者：
François Clarac
中科院分区：
文献类型：
--
作者：
Y. Sqalli;J. Cazalets;François Clarac
1.研究了哺乳动物产生自发活动的腰椎网络的振荡特性。这些实验在来自新生大鼠的体外分离的脊髓制备物上进行。在生理盐水中加入5-羟色胺（5-HT）和N-甲基-D-天冬氨酸（NMDA）兴奋性氨基酸受体激动剂（N-甲基-D，L-天冬氨酸，NMA）诱导前根中记录的节律性运动样活动。2.节律性运动样活动的周期可以通过组合不同浓度的神经递质来设定。组合发射器还作用于周期值的瞬时变化。当5-HT与NMA混合时，从一个周期到另一个周期的期间的稳定性增加，与单独浴用化合物诱导的活性相比。3.用K（+）诱导的去极化来设置神经元膜电位。K+浓度的这些系统性变化导致了周期值的变化。4.刺激背根会重置持续的节奏。相位响应曲线的绘制表明，脊髓网络表现出不同的敏感性，相同的刺激取决于刺激施加的相位。感觉放电的周期性齐射可诱导自由活动。平均而言，夹带发生在休息期的-28%至36%之间。由于腰段完全隔离的蔗糖阻断所有下行神经元的活动，夹带的自发活动必须直接发生在腰椎水平。5.总之，我们的数据表明，在出生时，脊髓网络产生的节律活动是基于显示振荡特性的神经元结构。在这个年龄段，外周感觉传入已经与中央模式发生器建立了联系。这些感觉输入能够逐步控制脊髓网络的循环活动。
1. The oscillatory properties of the lumbar spinal networks that generate locomotor activity in mammals were studied. These experiments were performed on an in vitro isolated spinal cord preparation from newborn rats. Adding to the saline serotonin (5-HT) and N-methyl-D-aspartate (NMDA) excitatory amino acid receptor agonist (N-methyl-D,L-aspartate, NMA) induced rhythmic locomotor-like activity that was recorded in the ventral roots. 2. The period of the rhythmic locomotor-like activity could be set by combining the neurotransmitters at various concentrations. The combined transmitters also acted on the instantaneous variations of the period value. The stability of the period from one cycle to another increased when 5-HT was mixed with NMA compared with the activity induced by bath application of the compound alone. 3. K(+)-induced depolarizations were used to set the neuron membrane potential. These systematic changes in the K+ concentration resulted in a change in the period value. 4. Stimulation of the dorsal roots reset the ongoing rhythm. Phase-response curves were drawn up that showed that the spinal networks exhibit a differential sensitivity to the same stimulus depending on the phase at which the stimulus is applied. The free-running activity could be entrained by the cyclic volleys of sensory discharges. Entrainment occurred, on average, between -28 and 36% of the rest period. Because the lumbar segments were completely isolated by means of a sucrose blockade of all descending neuronal activity, the entrainment of the locomotor activity must take place directly at the lumbar level. 5. In conclusion, our data show that, at birth, the rhythmic activity produced by the spinal networks is based on a neuronal architecture that displays oscillatory properties. At this early age, the peripheral sensory afferents have already established connections with the central pattern generator. These sensory inputs are able to control the cycling activity of the spinal networks step by step.