EFFECT OF CEREBELLECTOMY ON CATS VESTIBULO-OCULAR INTEGRATOR
EFFECT OF CEREBELLECTOMY ON CATS VESTIBULO-OCULAR INTEGRATOR
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DOI：
10.1016/0006-8993(74)90961-5
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发表时间：
1974-01-01
期刊：
影响因子：
2.9
通讯作者：
ROBINSON, DA
中科院分区：
文献类型：
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作者：
ROBINSON, DA
(1)观察小脑切除术前后猫眼在视觉固定、黑暗中尝试固定和旋转性眼球震颤时的眼球运动。(2)小脑切除术后，眼跳、眼动、前庭眼震等眼球运动在表面上恢复正常。然而，猫在黑暗中无法保持稳定的眼睛位置。眼球漂移有两个来源；眼球在跳眼后滑回某个中性点并缓慢地游离于中性点。(4) post-saccadic滑是指数在形状和时间常数为1.3秒。(5)post-saccadic滑的解释是,vestibulo-ocular积分器位于脑桥但漏水的积分器的时间常数只有1.3秒。小脑在某种程度上改善了积分器的性能通过提高其时间常数高于20秒。(6)影响的事实,破积分器跳阅和前庭眼球震颤的证据积分器是共享的跳眼和前庭系统。游离中性点被认为是小脑切除术释放的一种内部噪声。(8)小脑的一种眼动功能似乎是在正常的光动力机制不足时，利用视网膜外的眼睛位置知识，试图防止眼睛在非常昏暗的照明下四处飘移。由于它可以同时解释中性点漂移的衰减和积分器时间常数的增加，因此建议涉及一个单一的小脑机制。
(1) Cat eye movements during fixation with vision, attempted fixation in the dark and during rotatory nystagmus were examined before and after cerebellectomy.(2) After cerebellectomy most eye movements such as saccades, optokinetic and vestibular nystagmus superficially appeared to return to normal.(3) However, the cats were unable to maintain a steady eye position in the dark. Eye drift came from two sources; a post-saccadic slip of the eye back to some neutral point and a slow wandering of that neutral point.(4) The post-saccadic slip was exponential in shape and had a time constant of 1.3 sec.(5) The interpretation of post-saccadic slip is that the vestibulo-ocular integrator is located in the pons but it is a leaky integrator with a time constant of only 1.3 sec. The cerebellum somehow improves this integrator's performance by raising its time constant above 20 sec.(6) The fact that the leaky integrator affected both saccades and vestibular nystagmus is evidence that the integrator is shared by the saccadic and vestibular systems.(7) The wandering neutral point is regarded as a form of internal noise that is released by cerebellectomy.(8) It appears that one oculomotor function of the cerebellum is to use extra-retinal knowledge of eye position to try and prevent the eyes from drifting about in very dim illumination when the normal optokinetic mechanism becomes inadequate. It is suggested that a single cerebellar mechanism is involved since it could simultaneously account for the attenuation of neutral point drift and the increase in the integrator time constant.