Adaptations in glutamate and glycine content within the lumbar spinal cord are associated with the generation of novel gait patterns in rats following neonatal spinal cord transection.
Adaptations in glutamate and glycine content within the lumbar spinal cord are associated with the generation of novel gait patterns in rats following neonatal spinal cord transection.
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DOI：
10.1523/jneurosci.3499-11.2011
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发表时间：
2011-12-14
期刊：
影响因子：
--
通讯作者：
de Leon RD
中科院分区：
文献类型：
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作者：
Cantoria MJ;See PA;Singh H;de Leon RD
脊髓横断后，产生的踏步取决于神经递质系统完全包含在当地的腰髓。谷氨酸和甘氨酸可能起着重要的作用，但令人惊讶的是，很少有人知道这两个关键神经递质的含量如何变化，以实现脊髓损伤后的负重行走。我们研究了脊髓横断大鼠腰髓中谷氨酸和甘氨酸的水平。大鼠（n=48）在五天大时接受脊髓横断，四周后，一半接受机器人跑步机系统的训练，剩下的一半是未经训练的对照组。通过高效液相色谱（HPLC）分析谷氨酸和甘氨酸含量显示，训练显著提高了腰髓中两种神经递质的水平，超过了正常水平。这两种神经递质的水平显着相关的能力，在训练过程中执行独立的步进。谷氨酸和甘氨酸水平在未训练和正常大鼠之间或在训练和未训练大鼠之间没有显著差异。有一个趋势，VGLUT1和GLYT2运动神经元周围的训练与未训练的大鼠的免疫组化分析的基础上表达。训练提高了在一系列重量支撑水平下产生步进的能力，但没有恢复正常的步进特征。这些结果表明，在训练脊髓横断大鼠的腰椎回路的重塑涉及的适应性的谷氨酸能和甘氨酸能神经递质系统。这些适应可能有助于产生新的步态模式后，完全脊髓横断。
After spinal cord transection, the generation of stepping depends on neurotransmitter systems entirely contained within the local lumbar spinal cord. Glutamate and glycine likely plays important roles, but surprisingly, little is known about how the content of these two key neurotransmitters changes in order to achieve weight bearing stepping after spinal cord injury. We studied the levels of glutamate and glycine in the lumbar spinal cord of spinally transected rats. Rats (n=48) received spinal cord transection at five days of age and four weeks later, half were trained to step using a robotic treadmill system and the remaining half were untrained controls. Analyses of glutamate and glycine content via high-performance liquid chromatography (HPLC) showed training significantly raised the levels of both neurotransmitters in the lumbar spinal cord beyond normal. The levels of both neurotransmitters were significantly correlated with the ability to perform independent stepping during training. Glutamate and glycine levels were not significantly different between Untrained and Normal rats or between Trained and Untrained rats. There was a trend for higher expression of VGLUT1 and GLYT2 around motor neurons in Trained versus Untrained rats based on immunohistochemical analyses. Training improved the ability to generate stepping at a range of weight support levels, but normal stepping characteristics were not restored. These findings suggested that the remodeling of the lumbar spinal circuitry in Trained spinally transected rats involved adaptations in the glutamatergic and glycinergic neurotransmitter systems. These adaptations may contribute to the generation of novel gait patterns following complete spinal cord transection.