Cazalets J R, Bertrand S
CNRS, Laboratoire de Neurobiologie et Mouvements, 31 chemin Joseph Aiguier BP 71, 13402 Marseille cedex 9, France.
Eur J Neurosci. 2000 Aug;12(8):2993-3002. doi: 10.1046/j.1460-9568.2000.00169.x.
We have studied the rhythm-generating capabilities of the lumbar, sacral and coccygeal (Co) areas using an isolated spinal cord preparation of the newborn rat. The bath-application of a mixture of N-methyl-D-L-aspartate (NMA) and serotonin (5-HT) on the whole spinal cord induced a coordinated rhythmic activity that could be recorded from the lumbar to the coccygeal ventral roots. The phase relationships and mean burst duration between the activity in the rostral lumbar segments and the activity in the sacral segments was analysed. The direct activation of the sacral network, by using sections or by selective pharmacological activation, showed that these caudal segments possess their own rhythmogenic capability. By combining section experiments and compartmentation of the spinal cord, we demonstrated that a strong coupling exists between the lumbar and sacral motor networks. In addition, we found that in an intact spinal cord the activity of the sacral networks is driven by the lumbar networks. We have found that different modes of coordination between the lumbar and the sacral activity may occur. Finally, we have shown that the coupling between the lumbar and sacral networks can be modified by sensory inputs, suggesting that the spinal machinery could modulate and adapt the coupling of these two spinal networks.
我们使用新生大鼠的离体脊髓标本，研究了腰段、骶段和尾段（Co）区域产生节律的能力。将N-甲基-D-天冬氨酸（NMA）和5-羟色胺（5-HT）的混合物浴用在整个脊髓上，诱导出一种可从腰段到尾段腹根记录到的协调性节律活动。分析了腰段头端节段与骶段活动之间的相位关系和平均爆发持续时间。通过切片或选择性药理激活直接激活骶段网络，结果表明这些尾段节段具有自身的节律生成能力。通过结合切片实验和脊髓分隔，我们证明了腰段和骶段运动网络之间存在强耦合。此外，我们发现，在完整脊髓中，骶段网络的活动由腰段网络驱动。我们发现，腰段和骶段活动之间可能会出现不同的协调模式。最后，我们表明，腰段和骶段网络之间的耦合可被感觉输入所改变，这表明脊髓机制可以调节和适应这两个脊髓网络的耦合。
