Clément Gilles, Flandrin Jean-Marc, Courjon Jean-Hubert
Centre de Recherche Cerveau et Cognition, UMR 5549 CNRS/UPS, Toulouse, France.
Exp Brain Res. 2002 Jan;142(2):259-67. doi: 10.1007/s00221-001-0930-7. Epub 2001 Nov 20.
Changes in the horizontal vestibulo-ocular reflex (VOR) in darkness were investigated in naive cats during: (1) repeated sessions of angular velocity steps, (2) one continuous 1-h session of sinusoidal oscillations at 0.01, 0.02, 0.04, or 0.12 Hz, and (3) repeated sessions of 1-h sinusoidal oscillations at 0.02 and 0.04 Hz. Before and after each vestibular training, the VOR response parameters elicited by both velocity steps and sinusoidal oscillations were measured in order to evaluate the transfer of habituation from one stimulus to the other. After training with velocity steps, the amplitude and duration of the VOR to velocity steps decreased by about 67% and 52%, respectively. This vestibular habituation transferred to the VOR response generated by sinusoidal oscillations, since a decrease in VOR gain was observed at 0.02 and 0.04 Hz, and an increase in phase lead was observed at 0.02, 0.04, and 0.08 Hz. After 1 h exposure to sinusoidal oscillations, the VOR gain was only reduced by 21-28%, whereas VOR phase lead decreased. The same changes were observed during subsequent sessions, with no retention of the response decrements from one session to the next. At the end of sinusoidal training, the amplitude of the VOR generated by velocity steps was slightly altered. After sinusoidal training, the weak changes in the VOR gain accompanied by a decrease in the VOR phase lead, and the absence of retention of these effects from one session to the next, suggest these changes are not characteristics of a vestibular habituation. Previous reports of vestibular habituation induced by repeated sinusoidal oscillations may be confounded by the fact that the angular velocity steps used for quantifying the effects may have been responsible for this habituation.
在未接触过实验的猫中，研究了黑暗环境下水平前庭眼反射（VOR）的变化，实验过程包括：（1）重复进行角速度阶跃实验；（2）连续1小时进行频率为0.01、0.02、0.04或0.12赫兹的正弦振荡实验；（3）重复进行频率为0.02和0.04赫兹的1小时正弦振荡实验。在每次前庭训练前后，测量由速度阶跃和正弦振荡引发的VOR反应参数，以评估习惯化从一种刺激向另一种刺激的转移情况。在进行速度阶跃训练后，VOR对速度阶跃的幅度和持续时间分别下降了约67%和52%。这种前庭习惯化转移到了由正弦振荡产生的VOR反应中，因为在0.02和0.04赫兹时观察到VOR增益下降，在0.02、0.04和0.08赫兹时观察到相位超前增加。在暴露于正弦振荡1小时后，VOR增益仅降低了21 - 28%，而VOR相位超前减少。在后续实验中观察到相同的变化，且各实验之间没有反应递减的留存。在正弦训练结束时，由速度阶跃产生的VOR幅度略有改变。正弦训练后，VOR增益的微弱变化伴随着VOR相位超前的减少，且这些效应在各实验之间没有留存，这表明这些变化不是前庭习惯化的特征。先前关于重复正弦振荡诱导前庭习惯化的报道可能因用于量化效应的角速度阶跃可能导致这种习惯化这一事实而受到混淆。
