权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Physiological studies on the development of neuronal mechanisms generating locomotion in the rat spinal cord

大鼠脊髓运动神经元机制发育的生理学研究

基本信息

批准号：
61570059
负责人：
KUDO Norio
金额：
$ 1.22万
依托单位：
University of Tsukuba
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1986
资助国家：
日本
起止时间：
1986 至 1987
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-61570059/
关键词：
N-methyl-D L-aspartate Rat Spinal cord Locomotion Rhythm generator Development 摘出標本 N-Methyl-D,L-aspartate

项目摘要

Effects of N-methyl-D,L-aspartate (NMA) on the generation of locomortor activity were studied using isolated lumbar spinal cord-hind limb preparations in new-born rats.Electromyographic activities were recorded from the ankle flexor and extensor muscles of both sides. Bath-applied NMA (10-30 <micrn>M) evoked alternating rhythmic activity between the flexors and extensors. The frequency of the rhythmic activity in each muscle depended on the NMA dose. The mean burst duration in extensors was considerably longer than that in flexors at low concentrations of NMA. When the NMA dose was increased, the mean burst duration in extensors markedly decreased, compared with that in flexors. The activity in the corresponding muscles of the two hind limbs always occurred alternatingly within the concentration ranged described above. This pattern of muscle activity was not affected by the dorsal root transection. The NMA-induced rhythmic activity was also observed after the spinal cord was split mid- … More sagittally. However, the frequency of the rhythmic activity was significantly lower and the mean burst duration in each muscle much longer than those before splitting. It was concluded that central rhythm generators, activated by NMA, exist in both sides of the lumbar spinal cord.The development of rhythmic motor activity was also studied using isolated lumbar spinal cord preparations of rat fetuses. Rhythmic motor activity was evoked by bath application of NMA and recorded through the ventral roots on both sides of the lumbar spinal cord. It was found that rhythmic activity in the ventral roots was elicited by bath-applied NMA at and after E15.5. The mean frequency of the rhythmic activity increased with age. The rhythythmic activity was also evoked at all stages after splitting the spinal cord midsagitally, indicating that each side of the spinal cord has neuronal circuits for rhythm generation even at the fetal stage.the phase relationship of the rhythmic activities between the two sides of the ventral roots was synchrous st E15.5 and E16.5, independent at E17.5 and alternating at @18.5-20.5. At E17.5. the addition of strvchnine changed the independent rhythimic activities between the two sides to a synchrounous pattern, while at earlier stages it had no effect. This suggets that some inhibitory pathways to play an inportant role of functional couplimg between the two sides of neuronal circuits at this stage. Less

采用新生大鼠腰段脊髓-后肢分离模型，观察N-甲基-D，L-天冬氨酸对运动活动产生的影响，记录两侧踝屈肌和伸肌的肌电活动。沐浴NMA(10-30；microrn&gt；M)可引起屈肌和伸肌之间交替的节律性活动。每块肌肉节律性活动的频率取决于NMA的剂量。在低浓度的NMA作用下，伸肌的平均爆发持续时间明显长于屈肌。与屈肌相比，随着NMA剂量的增加，伸肌的平均爆发持续时间明显缩短。在上述浓度范围内，双后肢相应肌肉的活动总是交替发生的。这种肌肉活动模式不受背根切断的影响。在…中期切断脊髓后，也观察到NMA诱导的节律性活动更准确地说。但节律性活动的频率明显低于分裂前，各肌的平均爆发持续时间明显长于分裂前。结论：NMA激活的中枢节律产生器存在于双侧腰段脊髓，并用分离的胎鼠腰段脊髓标本研究了节律性运动活动的发展。应用NMA浴液诱发节律性运动活动，并通过双侧腰髓腹根记录。结果发现，在胚胎期15.5天及以后，沐浴NMA可引起前根的节律性活动。节律性活动的平均频率随年龄增长而增加。腹根两侧节律活动的时相关系为E15.5和E16.5，E17.5独立，@18.5-20.5交替。在E17.5。士的宁的加入使两侧独立的节律活动改变为同步模式，而在早期阶段则没有影响。提示在这一阶段，一些抑制通路在神经元环路两侧的功能偶联中起着重要作用。较少