Anatomical and functional segregation in the stapedius motoneuron pool of the cat.
Anatomical and functional segregation in the stapedius motoneuron pool of the cat.
复制标题
猫镫骨运动神经元池的解剖和功能分离。
DOI：
10.1152/jn.1988.60.3.1160
复制
发表时间：
1988
影响因子：
2.5
通讯作者：
GuinanJr,JJ
中科院分区：
文献类型：
--
作者：
McCue,MP;GuinanJr,JJ
1.在猫的镫骨肌中，在向任一耳呈现强烈声音的开始后6-10 ms可检测到肌电图活动（EMG）。在脑干损伤前和后，通过肌电图测量同侧和对侧声音诱发的镫骨肌反射。在某些情况下，镫骨肌运动轴突被切断;在其他情况下，含有运动神经元细胞体的脑干区域被电解破坏。2.电解病变接触解剖学上分离的镫骨肌运动神经元（腹内侧周组）的集群大大降低了对侧声音的反应，而不会明显影响同侧声音的反应。3.在其他脑干区域的电解质病变有不同的影响，一个似乎减少同侧声音选择性的反应，而其他减少两种反应或几乎没有影响。4.在第四脑室底部的面丘处切断镫骨肌运动轴突的子集后，对对侧声音的反应几乎被消除，而对同侧声音的实质性反应仍然存在。5.结果是一致的假设，即输入从两个耳蜗分布不均匀的镫骨肌运动神经元池中的这样一种方式，以产生分离的功能，在一个脑干区域的运动神经元优先（或专门）对侧的声音和运动神经元在其他地区优先（或专门）同侧的声音。镫骨肌运动神经元池的声输入的这种地形组织产生了一个“中央分区”在镫骨肌声反射在某些方面类似于本体感受脊髓反射中观察到的分区。
1. Electromyographic activity (EMG) is detectable in the feline stapedius muscle 6-10 ms after the onset of an intense sound presented to either ear. Stapedius reflexes evoked by ipsilateral and contralateral sound were measured electromyographically before and after brain stem lesions were made. In some cases, stapedius motor axons were cut; in others, brain stem regions containing motoneuron cell bodies were destroyed electrolytically. 2. Electrolytic lesions that contacted an anatomically separate cluster of stapedius motoneurons (the ventromedial perifacial group) greatly reduced responses to contralateral sound without noticeably affecting responses to ipsilateral sound. 3. Electrolytic lesions in other brain stem areas had different effects; one appeared to reduce responses to ipsilateral sound selectively, whereas others reduced both responses or had little effect. 4. After subsets of stapedius motor axons were cut at the facial colliculus in the floor of the fourth ventricle, responses to contralateral sound were almost eliminated, while substantial responses to ipsilateral sound remained. 5. The results are consistent with the hypothesis that inputs from the two cochleas are distributed inhomogeneously across the stapedius motoneuron pool in such a way as to produce a segregation of function, with motoneurons in one brain stem region responding preferentially (or exclusively) to contralateral sound and motoneurons in other regions responding preferentially (or exclusively) to ipsilateral sound. This topographic organization of acoustic input to the stapedius motoneuron pool produces a "central partitioning" in the acoustic stapedius reflexes similar in some respects to the partitioning observed in proprioceptive spinal reflexes.