Neuronal bursting induced by NK3 receptor activation in the neonatal rat spinal cord in vitro.
Neuronal bursting induced by NK3 receptor activation in the neonatal rat spinal cord in vitro.
复制标题
体外新生大鼠脊髓中 NK3 受体激活诱导的神经元爆发。
DOI：
10.1152/jn.2001.86.6.2939
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发表时间：
2001
影响因子：
2.5
通讯作者：
A. Nistri
中科院分区：
文献类型：
--
作者：
C. Marchetti;A. Nistri
使用腰部运动神经元的细胞内记录和新生大鼠离体脊髓腹根的细胞外记录来研究 NK3 速激肽受体介导的兴奋机制。选择性NK3激动剂senktide或[MePhe7]神经激肽B诱导缓慢去极化和叠加振荡（平均周期+/- SD为2.8 +/- 0.8秒），在大多数情况下，在节段水平上表现出左右交替，并且在同一侧的L2和L5之间同步。在激动剂清除期间（5-20分钟），出现了一种延迟形式的过度兴奋，由持续8 +/- 2 s的爆发（平均爆发间间隔55 +/- 21 s）组成，并伴有通常具有同源节段交替和异源节段同步性的叠加振荡。这种爆发伴随着背根刺激引起的 GABA 能背根电位的抑制和运动神经元记录的反复抑制性突触后电位的抑制。尽管爆发，运动神经元膜电位恢复到基线，同时输入电阻增加。爆发是由先前的 NK3 受体激活触发的网络依赖性现象，因为爆发被谷氨酸受体拮抗剂抑制，并且对运动神经元膜电位或随后使用 NK3 受体拮抗剂不敏感。 NK3 受体与 N-甲基-D-天冬氨酸 (NMDA) 和 5-羟色胺 (5-HT) 协同作用，触发完全交替的运动样节律，而 NK3 受体拮抗作用则破坏相同的节律。总之，在新生大鼠脊髓中，NK3 受体可以主要通过节段水平的交替来触发节律活动，但同侧运动池之间具有同步耦合。 NK3 受体激活还可以促进 NMDA 和 5-HT 诱导的虚构运动模式。
Intracellular recording from lumbar motoneurons and extracellular recording from ventral roots of the neonatal rat isolated spinal cord were used to study the mechanisms responsible for the excitation mediated by NK3 tachykinin receptors. The selective NK3 agonists senktide or [MePhe7]neurokinin B induced a slow depolarization with superimposed oscillations (mean period +/- SD was 2.8 +/- 0.8 s) that, in the majority of cases, showed left-right alternation at segmental level and were synchronous between L2 and L5 of the same side. During agonist wash out (5-20 min) a delayed form of hyperexcitability emerged consisting of bursts lasting 8 +/- 2 s (average interburst interval 55 +/- 21 s) with superimposed oscillations usually with homosegmental alternation and heterosegmental synchronicity. Such bursting was accompanied by depression of GABAergic dorsal root potentials evoked by dorsal root stimulation and of the recurrent inhibitory postsynaptic potential recorded from motoneurons. Despite bursting, motoneuron membrane potential returned to baseline while input resistance was increased. Bursts were a network-dependent phenomenon triggered by previous NK3 receptor activation because bursting was suppressed by glutamate receptor antagonists and was insensitive to motoneuron membrane potential or subsequent application of an NK3 receptor antagonist. NK3 receptors operated synergistically with N-methyl-D-aspartate (NMDA) and 5-hydroxytryptamine (5-HT) to trigger fully alternating locomotor-like rhythms while NK3 receptor antagonism disrupted the same rhythm. In summary, in the neonatal rat spinal cord NK3 receptors could trigger rhythmic activity predominantly with alternation at segmental level but with synchronous coupling between ipsilateral motor pools. NK3 receptor activation could also facilitate fictive locomotor patterns induced by NMDA and 5-HT.
影响因子：
2.5
作者：
Whelan, P;Bonnot, A;O'Donovan, MJ
通讯作者：
O'Donovan, MJ