BILATERAL LABYRINTHECTOMY IN THE CAT - EFFECTS ON THE POSTURAL RESPONSE TO TRANSLATION
BILATERAL LABYRINTHECTOMY IN THE CAT - EFFECTS ON THE POSTURAL RESPONSE TO TRANSLATION
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DOI：
10.1152/jn.1995.73.3.1181
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发表时间：
1995-03-01
影响因子：
2.5
通讯作者：
MACPHERSON, JM
中科院分区：
文献类型：
--
作者：
INGLIS, JT;MACPHERSON, JM
1. 本研究考察了前庭传入信息在四只猫的姿势反应中的作用，这些反应是由站立时支撑面的运动引起的。在双侧迷路切除术前后，动物暴露于支撑面在水平面上八个均匀间隔方向的线性平移。姿势反应被量化为每只脚爪下的地面反作用力和选定肌肉的诱发活动。在迷路切除后的1-3天内，猫能够站在平台上，并且能够在所有的立场扰动中保持平衡，即使它们站在完全黑暗的环境中，完全没有视觉信息。损伤后，体位反应表现为正常的潜伏期和正常的肌电（EMG）反应时空模式。力响应模式显示了完整动物体位反应特征的力约束策略。损伤后唯一的姿势反应缺陷是高心率，或活跃的过度反应，导致动物在某种程度上失去平衡，但不会损害它们保持直立的能力。在试验过程中对动物质心轨迹的分析表明，高心率是由于动物的异常大的主动反应，而不能归因于肌肉骨骼系统被动僵硬的变化。高心率是短暂的，在10-15 d的快速补偿期后，反应幅度恢复到控制水平。由此得出结论，前庭信息对于触发对支撑面平移的快速、自动的姿势反应不是必需的，对于诱发反应的选择或形成也不是必需的。相反，体感信息似乎在这些姿势调整中占主导地位。然而，前庭传入输入确实影响姿势反应的尺度。
1. This study examined the role of vestibular afferent information on the postural responses of four cats, evoked by movements of the support surface during stance. Animals were exposed to linear translations of the supporting surface in eight evenly spaced directions in the horizontal plane, before and after bilateral labyrinthectomy. Postural responses were quantified in terms of the ground reaction forces under each paw and the evoked activity in selected muscles.2. The cats were able to stand on the platform within 1-3 days after labyrinthectomy and were able to maintain balance during all perturbations of stance, even when they stood in total darkness, completely deprived of visual information. After lesion, postural responses were characterized by normal latency and normal spatial and temporal patterning of electromyographic (EMG) response. The pattern of force response showed the force constraint strategy that characterizes postural responses in the intact animal.3. The only deficit in the postural response after lesion was a hypermetria, or active over-response that caused the animals to overbalance somewhat but did not impair their ability to remain upright. Analysis of the trajectory of the animal's center of mass during the trials indicated that the hypermetria was due to an abnormally large, active response on the part of the animal and could not be attributed to changes in the passive stiffness of the musculoskeletal system. The hypermetria was transient, and response amplitude returned to control levels after the rapid compensation phase of 10-15 days.4. it is concluded that vestibular information is not essential for triggering the rapid, automatic postural response to translations of the support surface, nor is it necessary for the selection or shaping of the evoked response. Instead, somatosensory information appears to predominate in these postural adjustments. However, vestibular afferent input does influence the scaling of the postural response.