Time course of vestibuloocular reflex suppression during gaze shifts
Time course of vestibuloocular reflex suppression during gaze shifts
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DOI：
10.1152/jn.01156.2003
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发表时间：
2004-12-01
影响因子：
2.5
通讯作者：
Sylvestre, PA
中科院分区：
文献类型：
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作者：
Cullen, KE;Huterer, M;Sylvestre, PA
虽然许多研究已经探讨了前庭眼（VOR）在注视转移过程中的状态，但其确切状态仍然令人费解。本研究的目的是精确地评估VOR抑制的动态之前，整个过程中，刚刚凝视转移后。用力矩电机对3只恒河猴进行快速（100度/秒）、短时（20-30 ms）的头部水平扰动。首先比较了在15度、40度和60度注视移位期间由这种短暂头部扰动引起的VOR的状态。在两只猴子中，凝视转移开始（40 ms）后VOR抑制水平随凝视转移幅度增加而增加，接近80%和35%的值。相比之下，在第三只猴子中，VOR对于所有注视移位幅度都没有显著衰减。VOR衰减的时间过程，然后进行了更详细的研究，所有三只猴子施加相同的短期头部扰动40，100和150毫秒后开始的60度凝视转移。总的来说，我们发现了一个一致的趋势，即VOR抑制在凝视转移早期最大，并逐渐恢复到接近凝视转移结束时的正常值。然而，受试者之间的高变异性阻碍了建立凝视转移期间VOR抑制的绝对水平和时间过程的统一描述。我们认为，行为策略的差异可能占，至少部分地，这些科目之间的差异。
Although numerous investigations have probed the status of the vestibuloocular (VOR) during gaze shifts, its exact status remains strangely elusive. The goal of the present study was to precisely evaluate the dynamics of VOR suppression immediately before, throughout, and just after gaze shifts. A torque motor was used to apply rapid (100degrees/s), short-duration (20-30 ms) horizontal head perturbations in three Rhesus monkeys. The status of the VOR elicited by this transient head perturbation was first compared during 15, 40, and 60degrees gaze shifts. The level of VOR suppression just after gaze-shift onset (40 ms) increased with gaze-shift amplitude in two monkeys, approaching values of 80 and 35%. In contrast, in the third monkey, the VOR was not significantly attenuated for all gaze-shift amplitudes. The time course of VOR attenuation was then studied in greater detail for all three monkeys by imposing the same short-duration head perturbations 40, 100, and 150 ms after the onset of 60degrees gaze shifts. Overall we found a consistent trend, in which VOR suppression was maximal early in the gaze shift and progressively recovered to reach normal values near gaze-shift end. However, the high variability across subjects prevented establishing a unifying description of the absolute level and time course of VOR suppression during gaze shifts. We propose that differences in behavioral strategies may account, at least in part, for these differences between subjects.