Dopaminergic modulation of spinal neuronal excitability
Dopaminergic modulation of spinal neuronal excitability
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DOI：
10.1523/jneurosci.1279-07.2007
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发表时间：
2007-11-28
影响因子：
5.3
通讯作者：
Whelan, Patrick J.
中科院分区：
文献类型：
--
作者：
Han, Pengcheng;Nakanishi, Stan T.;Whelan, Patrick J.
多巴胺（DA）可以调节脊髓网络和反射，这是众所周知的。DA纤维和受体存在于脊髓中，并且在脊髓内释放DA的证据已经发表。一个关键的空白是缺乏关于多巴胺能调节哺乳动物脊髓运动神经元和腹侧中间神经元的内在和突触特性的数据。在本文中，我们通过研究DA对运动系统兴奋作用的细胞机制来解决这个问题。我们研究了DA对位于第八层的运动神经元和Hb9中间神经元这两类运动控制重要细胞的影响。我们发现DA可以通过减少第一次峰潜伏期和后超极化来增强脊髓运动神经元的兴奋性。总的来说，这会导致频率电流斜率的增加，这可能归因于I-A和SKCa（小电导钙激活K+通道）电流的调制。我们还证明，DA增加谷氨酸能传递到运动神经元。我们的数据还表明，DA可以稳定条件性破裂中间神经元的节律输出。总的来说，这些数据表明DA对腹侧脊髓神经元的内在和突触特性具有广泛的作用。
It is well recognized that dopamine ( DA) can modulate spinal networks and reflexes. DA fibers and receptors are present in the spinal cord, and evidence for DA release within the spinal cord has been published. A critical gap is the lack of data regarding dopaminergic modulation of intrinsic and synaptic properties of motoneurons and ventral interneurons in the mammalian spinal cord. In this paper, we address this issue by examining the cellular mechanisms underlying the excitatory effect of DA on motor systems. We examine the effects of DA on two classes of cells important for motor control, motoneurons and Hb9 interneurons, located in lamina VIII. We show that DA can boost excitability in spinal motoneurons by decreasing the first spike latency and the afterhyperpolarization. Collectively, this leads to an increase in the frequency - current slope likely attributable to modulation of I-A and SKCa (small-conductance calcium-activated K+ channel) currents. We also demonstrate that DA increases glutamatergic transmission onto motoneurons. Our data also suggest that DA stabilizes the rhythmic output of conditionally bursting interneurons. Collectively, these data indicate that DA has widespread actions on intrinsic and synaptic properties of ventral spinal neurons.