Development of Inhibitory Pathways in the Rat Spinal Cord

大鼠脊髓抑制途径的发展

• 批准号: 63480103
• 负责人: KUDO Norio
• 金额: $ 4.03万
• 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 (B)
• 财政年份: 1988
• 资助国家: 日本
• 起止时间: 1988 至 1990
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-63480103/
• 关键词: Spinal cord; Inhibition; Development; Reflex; Locomotion; Rat; Fetus; In vitro; 脊髄切断; リズム運動; CPG; 興奮性アミノ酸; 抑制効果; 細胞内記録

Development of inhibitory pathways in the lumbar spinal cord was investigated electrophysiologically using an isolated spinal cord preparation in fetal and new-born rats.1. Development of inhibition in the reflex pathway : Intracellular recordings from lumbal motoneurones at different ages revealed that inhibitory postsynaptic potentials (IPSPs) following stimulation of the dorsal root first appeared at embryonic days (E) 16.5, 5 days before birth. The frequency of occurrence of IPSPs were less than that of excitatory postsynaptic potentials (EPSPs) in individual motoneurones at this stage, indicating that inhibitory pathways would develop later than excitatory ones in the reflex arc. Chronic transection of the lower thoracic cord at E15.5 could not affect the later development of the inhibitory pathways.2. Development of inhibition in the rhythm generator : A neuronal circuit generating rhythmic motor activity was activated by bath application of N-methyl-D, L-aspartate (NMA). Rhythmic activities in the lumbar ventral roots first appeared at E15.5, though srychnine-sensitive inhibitoty action began toqfunction at E17.5 in this neuronal ciruit. The inhibition changed the pattern of activities in the ventral root on two sides from synchronized to alternating, as is the pattern of locomotion.

在胚胎和新生大鼠中，使用离体脊髓制备电生理学研究了腰髓抑制通路的发育。在反射通路中抑制的发展：来自不同年龄的腰运动神经元的细胞内记录显示，刺激背根后的抑制性突触后电位（IPSPs）首次出现在胚胎天（E）16.5，出生前5天。IPSPs的出现频率低于兴奋性突触后电位（EPSPs）在个别运动神经元在这个阶段，表明抑制性通路将发展晚于兴奋性的反射弧。在E15.5时慢性切断下胸髓对抑制通路的后期发展没有影响.节律发生器中抑制的发展：通过N-甲基-D，L-天冬氨酸（NMA）浴应用激活产生节律运动活动的神经元回路。腰神经前根的节律性活动在E15.5时首次出现，而在E17.5时，这个神经元回路中的斯律奇宁敏感性节律性活动开始起作用。这种抑制作用使两侧腹根的活动模式从同步变为交替，运动模式也是如此。

项目成果

工藤 典雄: "随意運動の機能分化一皮質脊髄路の発達" Clin.Neurosci.9. 49-51 (1991)

Norio Kudo：“随意运动的功能分化和皮质脊髓束的发育”Clin.Neurosci.9（1991）。

Kudo, N., Ozaki S. and Yamada, T.: "Development of inhibitory pathways in the lumbar spinal cord of rats." J. Physiol. Soc. Jpn.,. 50. 444 (1988)

Kudo, N.、Ozaki S. 和 Yamada, T.：“大鼠腰脊髓抑制通路的发展。”

Hongo,T.: "Spatial pattems of reflex evoked by pressure stimulation on the foot pads in cats" J.Physiol.420. 471-487 (1990)

Hongo,T.：“猫足垫压力刺激引起的反射空间模式”J.Physiol.420。

Kudo, N. and Yamada, T.: "Functional development of the spinal cord." Bull. TWIN.16. 15-25 (1988)

Kudo, N. 和 Yamada, T.：“脊髓的功能发育。”

S.Ozaki: "Spinal mechanisms of NMAーinduced rhythmic motor activity in the rat fetus" Neurosci.Res.suppl.11. S35 (1990)

S.Ozaki：“NMA 诱导大鼠胎儿节律性运动活动的脊髓机制”Neurosci.Res.suppl.11 (1990)。