Himi T, Igarashi M, Takeda N
Department of Otorhinolaryngology and Communicative Sciences, Baylor College of Medicine, Houston, Texas 77030.
Acta Otolaryngol. 1990 Mar-Apr;109(3-4):188-94. doi: 10.3109/00016489009107433.
The role of the cerebellar uvula and nodulus in vertical optokinetic after-nystagmus (OKAN) was studied in 4 squirrel monkeys. Aspiration ablation of the uvula and nodulus resulted in no significant change in the initial or peak gain of vertical optokinetic nystagmus (OKN) during the 24-week post-operative observation. However, the asymmetry of vertical OKAN was significantly altered. Using a protracted upward OK stimulus, slow phase-down OKAN-II, which was not seen pre-operatively, was significantly increased. In contrast, a downward OK stimulus produced little change in slow phase-up OKAN-II. Thus, the asymmetric degree of vertical OKAN-II was decreased after uvulonodulectomy. In addition, there was a post-operative reduction in the vertical oculomotor stability. When slow-phase eye velocity of OKAN was plotted along the time scale, the amplitude and frequency of the sinusoidal pattern was increased. OKAN-III and OKAN-IV were found in 50% of the monkeys after uvulonodulectomy. It is therefore thought that inhibition and directional control from the uvula and nodulus influence the stability and asymmetrical behaviour of the leaky integrator in the second order output system.
在4只松鼠猴中研究了小脑蚓垂和小结在垂直视动性眼震后眼震（OKAN）中的作用。对蚓垂和小结进行 aspiration 消融术后，在术后24周的观察期内，垂直视动性眼震（OKN）的初始增益或峰值增益无显著变化。然而，垂直OKAN的不对称性发生了显著改变。使用持续向上的OK刺激时，术前未见的慢相向下的OKAN-II显著增加。相比之下，向下的OK刺激对慢相向上的OKAN-II影响不大。因此，蚓垂小结切除术后垂直OKAN-II的不对称程度降低。此外，术后垂直眼动稳定性降低。当将OKAN的慢相眼速度沿时间尺度绘制时，正弦模式的幅度和频率增加。在蚓垂小结切除术后，50%的猴子出现了OKAN-III和OKAN-IV。因此，认为来自蚓垂和小结的抑制和方向控制影响了二阶输出系统中泄漏积分器的稳定性和不对称行为。
