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

Differentiation of Central Pattern Generators in the rat.

大鼠中枢模式发生器的分化。

基本信息

批准号：
09680810
负责人：
KUDO Norio
金额：
$ 2.11万
依托单位：
University of Tsukuba
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1998
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09680810/
关键词：
rat fetus spinal cord in vitro preparation rhythm central pattern generator 5-HT glycine development リズム運動グルタミン酸交代性リズム伸筋・屈筋抑制路

项目摘要

The rhythmic motor activity involved in locomotion is generally considered to be generated by interneuronal networks within the spinal cord. Developmental changes in the 5-HT-induced locomotor rhythm were examined in isolated spinal cord preparations taken from fetal rats. Motor activity was recorded from L2/L3 and L5 ventral roots, representing activity in flexors and extensors, respectively. Bath application of 5-HT evoked rhythmic bursts that were synchronized in all ventral roots studied at E16.5. At E18.5, 5-HT evoked rhythmic bursts that alternated between the two sides, while the bursts in the L2/L3 ventral root were synchronous with those in the ipsilateral L5 ventral root. At E20.5, 5-HT evoked alternate rhythmic bursts in L2/L3 and L5 ventral roots. In the presence of strychnine, 5-HT induced rhythmic bursts that were synchronized in all ventral roots studied at E18.5 and E20.5, suggesting that the change in the pattern of rhythmic motor activity that occurs with age is due to the development of glycine-mediated inhibition.In preparations from fetuses at the earlier stages (E14.5 - E16.5), we observed 5-HT evoked rhythmic bursts , which were synchronized on the two sides in the corresponding ventral roots. These rhythmic bursts were not blocked by kynurenate, the glutamate receptor blocker, though it was completely abolished by strychnine, the glycine receptor antagonist. A brief application of glycine evoked excitatory responses in the ventral roots. It is concluded that glycine functions transiently as excitatory transmitters at these stages.These results suggest that functional change in glycine-induced responses during development plays an important role in differentiation of the neuronal circuits generating locomotion.

运动中涉及的节律性运动活动通常被认为是由脊髓内的神经元间网络产生的。在取自胎鼠的分离脊髓标本中检查了 5-HT 诱导的运动节律的发育变化。从 L2/L3 和 L5 腹根记录运动活动，分别代表屈肌和伸肌的活动。 5-HT 的沐浴应用引起了在 E16.5 研究的所有腹侧根中同步的节律爆发。在E18.5，5-HT引起两侧交替的节律性爆发，而L2/L3腹侧根的爆发与同侧L5腹侧根的爆发同步。在 E20.5，5-HT 在 L2/L3 和 L5 腹根中引起交替的节律爆发。在士的宁存在的情况下，5-HT 诱导节律性爆发，这些节律性爆发在 E18.5 和 E20.5 研究的所有腹侧根中同步，表明随着年龄的增长而发生的节律性运动活动模式的变化是由于甘氨酸介导的抑制的发展所致。在早期胎儿 (E14.5 - E16.5) 的制剂中，我们观察到 5-HT 引起有节奏的爆发，在相应的腹根的两侧同步。这些节律性爆发并没有被谷氨酸受体阻断剂犬尿酸盐阻断，尽管它被甘氨酸受体拮抗剂士的宁完全消除。甘氨酸的短暂应用会引起腹侧根的兴奋反应。结论是，甘氨酸在这些阶段短暂地充当兴奋性递质。这些结果表明，发育过程中甘氨酸诱导的反应的功能变化在产生运动的神经元回路的分化中起着重要作用。