Activity of pyramidal tract neurons in the cat during postural corrections
Activity of pyramidal tract neurons in the cat during postural corrections
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DOI：
10.1152/jn.00577.2004
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发表时间：
2005-04-01
影响因子：
2.5
通讯作者：
Deliagina, TG
中科院分区：
文献类型：
--
作者：
Beloozerova, IN;Sirota, MG;Deliagina, TG
四足动物的背侧向上的身体方向是由姿势控制系统维持的。我们调查参与的运动皮层在这个系统中记录活动的锥体束神经元（PTNs）的肢体表示的运动皮层在姿势矫正。猫站在平台上，周期性地在额面倾斜，并在不同的身体配置保持平衡：头部向前（左右前肢对称交替加载），或头部自愿转向右侧或左侧（不对称加载）。我们发现，倾斜的姿势矫正反应包括接触力的增加和活动的肢体伸肌的一侧向下移动，和他们的减少对侧。PTNs的活动强烈调制的倾斜周期。各个PTNs的活性阶段分布在整个周期中。因此，由PTNs介导的皮层输出似乎与高度自动的运动活动密切相关，即维持身体姿势。头部转动引起的四肢不对称负荷导致倾斜运动反应的相应变化。这些自愿的姿势调整也很好地反映在PTNs的活动中。一部分PTNs的活动与接触力相关，在其他一些人与肢体肌肉活动;在其他人中，没有观察到与这些变量的相关性。PTNs群体的这种异质性表明个体PTNs的不同功能作用。
The dorsal side-up body orientation in quadrupeds is maintained by a postural control system. We investigated participation of the motor cortex in this system by recording activity of pyramidal tract neurons (PTNs) from limb representations of the motor cortex during postural corrections. The cat was standing on the platform periodically tilting in the frontal plane, and maintained equilibrium at different body configurations: with the head directed forward (symmetrically alternating loading of the left and right fore limbs), or with the head voluntary turned to the right or to the left (asymmetrical loading). We found that postural corrective responses to tilts included an increase of the contact forces and activity of limb extensors on the side moving down, and their decrease on the opposite side. The activity of PTNs was strongly modulated in relation to the tilt cycle. Phases of activity of individual PTNs were distributed over the cycle. Thus the cortical output mediated by PTNs appeared closely related to a highly automatic motor activity, the maintenance of the body posture. An asymmetrical loading of limbs, caused by head turns, resulted in the corresponding changes of motor responses to tilts. These voluntary Postural modifications were also well reflected in the PTNs' activity. The activity of a part of PTNs correlated well with contact forces, in some others with the limb muscle activity; in still others no correlation with these variables was observed. This heterogeneity of the PTNs Population suggests a different functional role of individual PTNs.