Mechanism of injury process and regeneration of the vestibular organ after drug intoxication.

通过改变钾离子浓度来记录半规管动作电位。结果表明，无论杯状物是否存在，这些电位都保持不变，这表明杯状物并不是感觉细胞的离子屏障。以成年牛蛙为实验动物，研究了链霉素(SM)对体位恢复的影响。SM中毒可引起不同程度的毛细胞损伤。体位恢复的程度与完整毛细胞的数量有很好的相关性。感觉细胞损伤越小，姿势恢复越好。并研究了丹参对前庭神经再生过程的影响。在不同条件下切断前庭神经，内脏完整或SM中毒。神经切断后毛细胞保持完整，8~9周内神经再生良好，身体平衡恢复正常。然而，当通过在神经断端之间插入一块骨来阻止神经再生时，恢复是不完整的。当损伤毛细胞后切断神经时，神经再生失败，姿势恢复不完全。这些结果表明，姿势恢复的程度取决于毛细胞功能和神经再生。此外，毛细胞功能对神经再生有很大的影响。完全体位恢复后切断前庭神经，第二次神经切除后体位变化较小，恢复时间较短。这表明，在青蛙中，在第一次神经切除后可以很容易地建立起中枢补偿。

The semicircular canal action potentials were recorded by changing potassium ion concentration. It turned out that the potentials stayd unchanged regardless whether or not the cupula is present, indicating the cupula does not serve as a barrier of ion to sensory cells. The action of streptomycin suflate (SM) on posture recovery was studied using adult bull frogs. SM intoxication resulted in various degrees of hair cell damage. Degree of posture recovery correlated well with the number of intact hair cell. The less the sensory cell damage, the better the posture recovery. The effect of SM on the regenerative process of the vestibular nerve was also studied. The vestibular nerve was sectioned in various conditions with intact endorgan or with SM intoxication. When the nerve was sectioned with the hair cells left intact, the nerve regenerated well and body balance recovered to normal in 8 to 9 weeks. However, when neural regeneration was blocked by inserting a piece of bone between the cut ends of nerve, recovery was incomplete. When the nerve was sectioned after damaging the hair cells, the nerve failed to regenerate and posture recovery was incomplete. These results suggest that the degree of posture recovery depends on hair cell function and neural regeneration. Furthermore, neural regeneration was strongly influenced by hair cell function. When the vestibular nerve was sectioned after complete posture recovery, the posture change was less and recovery time was shorter after the second neurectomy. This shows that in frogs central compensation could be easily established after the first neurectomy.