Effects of unilateral lesions of the flocculus on optokinetic and vestibuloocular reflexes of the rabbit.
Effects of unilateral lesions of the flocculus on optokinetic and vestibuloocular reflexes of the rabbit.
复制标题
单侧绒球损伤对兔视动和前庭眼反射的影响。
DOI：
10.1152/jn.1985.53.2.481
复制
发表时间：
1985
影响因子：
2.5
通讯作者：
Pettorossi,VE
中科院分区：
文献类型：
--
作者：
Barmack,NH;Pettorossi,VE
本文对21只家兔左小叶单侧病变前后水平光动反射（HOKR）和水平前庭反射（HVOR）进行了检测。在放置絮状病变后15分钟内观察到的直接效果是，当动物被置于完全黑暗的环境中时，眼球震颤缓慢地向病变对面的一侧移动。自发性眼球震颤持续数小时至两天，视小叶受损程度而定。如果前庭下核或前庭神经因手术而受损，其征象逆转，如果双侧迷路切除的兔单侧絮状病变则完全不存在。术后立即观察到的眼球自发漂移导致HVOR测量偏差，这取决于前庭刺激的频率。术后50天测量时，HVOR的增益和偏倚正常。术后50天测量，当刺激速度低于5度/秒时，单眼HOKR（左眼后前刺激）的增益显著降低。对小叶病变引起的下橄榄神经元变性的定量解剖分析表明，背帽神经元群的对侧细胞损失高达65%。这些数据表明，在单侧小叶状核损伤后，HOKR存在永久性缺陷，而HVOR则没有，这与小叶状核通过抑制前庭下核的活动调节来调节低速眼球运动的观点是一致的。
The horizontal optokinetic reflex (HOKR) and the horizontal vestibuloocular reflex (HVOR) were tested in 21 rabbits before and after unilateral lesions were made in the left cerebellar flocculus. The immediate effect, observed within 15 min following placement of a floccular lesion, was a conjugate nystagmus with the slow phase toward the side opposite to the lesion when the animal was placed in total darkness. This spontaneous nystagmus lasted from several hours to two days depending on the extent of damage to the flocculus. It was reversed in sign if the subjacent vestibular nuclei or vestibular nerve were damaged by the operation, and it was totally absent if the unilateral floccular lesions were made in rabbits that had been bilaterally labyrinthectomized. The spontaneous drift of the eyes observed immediately postoperatively caused a bias in measurement of the HVOR that was dependent on the frequency of vestibular stimulation. When measured 50 days postoperatively the HVOR had a normal gain and normal bias. When measured 50 days postoperatively the monocular HOKR (posteroanterior stimulation of the left eye) was significantly reduced in gain at stimulus velocities below 5 degrees/s. A quantitative anatomical analysis of the degeneration of inferior olivary neurons caused by lesions of the flocculus demonstrated contralateral cell loss of as much as 65% of the dorsal cap neuronal population. These data reveal a permanent deficit in the HOKR, but not the HVOR, following unilateral floccular lesions and are consistent with the idea that the flocculus contributes to the regulation of the low-velocity eye movements through the inhibitory modulation of the activity of the subjacent vestibular nuclei.