Role of GABA A inhibition in modulation of pyramidal tract neuron activity during postural corrections.
Role of GABA A inhibition in modulation of pyramidal tract neuron activity during postural corrections.
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GABA A 抑制在姿势矫正过程中锥体束神经元活动调节中的作用。
DOI：
10.1111/j.1460-9568.2007.05413.x
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发表时间：
2007
期刊：
影响因子：
--
通讯作者：
Beloozerova,IrinaN
中科院分区：
文献类型：
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作者：
Tamarova,ZinaidaA;Sirota,MikhailG;Orlovsky,GrigoriN;Deliagina,TatianaG;Beloozerova,IrinaN
在以前的研究中，我们证明了运动皮层的锥体束神经元（PTNs）的活动是调制的姿势校正引起的动物周期性倾斜。该调制包括在倾斜周期的一个阶段中活动的增加和在另一个阶段中活动的减少。已知运动皮质含有大量抑制性GABA能神经元。这些神经元如何参与PTNs的周期性调节？本研究的目的是研究运动皮层的GABA A抑制性神经元在姿势相关PTN活性调节中的作用。使用细胞外电极与附加的微量移液器，我们记录了活动的PTNs在猫保持平衡的倾斜平台上的GABA A受体拮抗剂gabazine或荷包牡丹碱的离子导入应用程序之前和之后。93%的PTNs的倾斜相关活性受到GABA A受体拮抗剂的影响。在88%的细胞中，峰值活性增加了75 ± 50%（平均值± SD）。 与此相反，谷活动变化的值要小得多，几乎一样多的神经元显示减少，显示增加。在73%的神经元中，峰活动的相位位置没有变化或变化不超过0.1个周期。 我们的结论是，运动皮层的GABA能系统减少了PTNs的姿势相关反应，但在决定其反应时间方面几乎没有作用。
In a previous study we demonstrated that the activity of pyramidal tract neurons (PTNs) of the motor cortex is modulated in relation to postural corrections evoked by periodical tilts of the animal. The modulation included an increase in activity in one phase of the tilt cycle and a decrease in the other phase. It is known that the motor cortex contains a large population of inhibitory GABAergic neurons. How do these neurons participate in periodic modulation of PTNs? The goal of this study was to investigate the role of GABAAinhibitory neurons of the motor cortex in the modulation of postural‐related PTN activity. Using extracellular electrodes with attached micropipettes, we recorded the activity of PTNs in cats maintaining balance on a tilting platform both before and after iontophoretic application of the GABAAreceptor antagonists gabazine or bicuculline. The tilt‐related activity of 93% of PTNs was affected by GABAAreceptor antagonists. In 88% of cells, peak activity increased by 75 ± 50% (mean ± SD). In contrast, the trough activity changed by a much smaller value and almost as many neurons showed a decrease as showed an increase. In 73% of the neurons, the phase position of the peak activity did not change or changed by no more than 0.1 of a cycle. We conclude that the GABAergic system of the motor cortex reduces the posture‐related responses of PTNs but has little role in determining their response timing.