Peripheral and central substrates of vestibulospinal reflexes.
Peripheral and central substrates of vestibulospinal reflexes.
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DOI：
10.1152/physrev.1978.58.1.80
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发表时间：
1978
影响因子：
33.6
通讯作者：
V. J. Wilson;B. Peterson
中科院分区：
文献类型：
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作者：
V. J. Wilson;B. Peterson
人类和其他哺乳动物的前庭器官由位于颞骨深处的充满液体的半规管和耳石器官组成。这组受体和与之相连的中枢神经回路的运动功能有两个方面：1)在头部运动时通过稳定眼睛在空间中的位置来维持视觉形象；2)稳定头部在空间中的位置。前者是由短暂的线性或角加速度引起的相性前庭-眼反射和头部位置相对于重力线性加速度的持续变化引起的强直性前庭-眼反射来实现的。后者是通过等效前庭脊髓反射来实现的。前庭脊髓相性反射和强直性反射的特点可以用一个例子来说明。当四足动物突然从正常站立位置向前倾斜时，其迷宫中的半规管感受器被由此产生的角加速度激活，耳石感受器被头部的线性加速度激活。这些感受器的激活反过来导致阶段性前庭脊髓反射，引起颈背肌肉收缩、前肢伸展和后肢屈曲。所有这些反射效应都倾向于抬高头部，尽管身体突然向前倾斜，但仍能保持头部在空间中的稳定。一旦头部被颈部肌肉的作用抬高，颈部反射会增强迷路反射产生的前肢伸展和后肢屈曲。
The vestibular apparatus of man and other mammals consists of fluidfilled semicircular canals and otolith organs lying deep in the temporal bone. The motor functions of this group of receptors and of the central neural circuitry to which it is connected are twofold: 1) to maintain the visual image by stabilizing the eyes in space during head movements and 2) to stabilize the position of the head in space. The former is achieved by phasic vestibulo-ocular reflexes elicited by transient linear or angular acceleration and by tonic vestibulo-ocular reflexes elicited by maintained changes in head position with respect to the linear acceleration of gravity. The latter is achieved by the equivalent vestibulospinal reflexes. The characteristics of phasic and tonic vestibulospinal reflexes can best be illustrated by an example. When a four-legged animal is suddenly pitched forward from its normal standing position, semicircular canal receptors in its labyrinth are activated by the resulting angular acceleration and otolith receptors are activated by the linear acceleration of the head. Activation of these receptors leads in turn to phasic vestibulospinal reflexes that cause contraction of dorsal neck muscles, extension of the forelimbs, and flexion of the hindlimbs. All these reflex effects tend to raise the head, keeping it stable in space despite the sudden forward pitching of the body. Once the head has been elevated by the action of neck muscles, neck reflexes will augment the forelimb extension and hindlimb flexion produced by labyrinthine reflexes.