Barmack N H
Department of Ophthalmology, Good Samaritan Hospital and Medical Center, Portland, Oregon 97209.
J Neurosci. 1988 Aug;8(8):2816-26. doi: 10.1523/JNEUROSCI.08-08-02816.1988.
The efficacy of the technique of semicircular canal plugging in selectively blocking the function of individual semicircular canals was evaluated in rabbits. The horizontal and vertical vestibuloocular reflexes (HVOR, VVOR) and the horizontal optokinetic reflex (HOKR) were measured before the horizontal or anterior semicircular canals (HSCs, ASCs) were plugged bilaterally with small spindles of silver wire. These reflexes were also measured after the plugs were removed. The gain of the HVOR was reduced to less than 0.05 at all frequencies tested after plugs were inserted into the HSCs. The gain of the HOKR was not influenced by the plugging operation. These data were interpreted to mean that the plugs blocked the normal fluid dynamics of the HSCs, but did not alter the spontaneous activity of HSC afferents. The gain of the VVOR was not reduced by plugs of the HSCs. The gain of the VVOR was reduced by plugs of the ASCs. The residual VVOR was attributed to stimulation of the utricular otoliths at lower frequencies and stimulation of the posterior semicircular canals at higher frequencies. The gain of the HVOR was reduced 10-40% by plugs of the ASCs. These data, in conjunction with the presence of a small residual gain of the HVOR following bilateral plugs of the HSCs, suggest that the ASCs contribute to the HVOR. The gains of the HVOR and VVOR recovered to within 88% of the preplug values once the plugs of the HSCs or ASCs were removed. However, the protracted time course of this recovery, 10-15 d, indicated that the plugging operation, although reversible, does cause some temporary damage to the peripheral labyrinth.
在兔子身上评估了半规管堵塞技术选择性阻断单个半规管功能的效果。在双侧用小银线纺锤体堵塞水平或前半规管（HSCs、ASCs）之前，测量水平和垂直前庭眼反射（HVOR、VVOR）以及水平视动反射（HOKR）。在移除堵塞物后也测量这些反射。将HSCs插入堵塞物后，在所有测试频率下，HVOR的增益均降低至小于0.05。堵塞操作未影响HOKR的增益。这些数据被解释为意味着堵塞物阻断了HSCs的正常流体动力学，但未改变HSC传入神经的自发活动。HSCs的堵塞物未降低VVOR的增益。ASCs的堵塞物降低了VVOR的增益。残余的VVOR归因于低频时椭圆囊耳石的刺激和高频时后半规管的刺激。ASCs的堵塞物使HVOR的增益降低了10 - 40%。这些数据，连同双侧堵塞HSCs后HVOR仍有小的残余增益，表明ASCs对HVOR有贡献。一旦移除HSCs或ASCs的堵塞物，HVOR和VVOR的增益恢复到堵塞前值的88%以内。然而，这种恢复的时间过程较长，为10 - 15天，表明堵塞操作虽然是可逆的，但确实会对外周迷路造成一些暂时损伤。
