Faulstich Bernd Michael, Onori Kimberly Ann, du Lac Sascha
Systems Neurobiology Laboratory, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA.
Vision Res. 2004 Dec;44(28):3419-27. doi: 10.1016/j.visres.2004.09.006.
Image stability during self-motion is achieved via a combination of the optokinetic and vestibulo-ocular reflexes (OKR and VOR). To determine whether distinct neuronal mechanisms are used to calibrate eye movements driven by visual and vestibular signals, we examined the developmental maturation and adaptive plasticity of the OKR and VOR in mice. The combined performance of the OKR and VOR, measured with infrared video oculography, produces nearly perfect gaze stability both in adult mice and in juveniles (postnatal days 21-26). Analyses of the OKR and VOR in isolation, however, indicate that VOR gains in juveniles are lower than in adult mice, while OKR gains are higher, indicating that juveniles rely more strongly on vision to stabilize gaze than do adults. Adaptive plasticity in the mouse OKR and VOR could be induced by 30 min of visual-vestibular mismatch training. Examination of the effects of training on the OKR and VOR revealed differential mechanisms and persistence of adaptive plasticity. Increases in VOR gain induced by rotating mice in the opposite direction to the visual surround were short-lasting and were accompanied by long-lasting increases in OKR gain. In contrast, decreases in VOR gain induced by rotating mice in the same direction as the visual surround were persistent and were accompanied by long-lasting increases in OKR gain. Vestibular training had little effect on either the OKR or VOR, while visual training induced robust and long-lasting increases in the OKR but had no effect on the VOR. These data indicate that multiple mechanisms of plasticity operate over distinct time courses to optimize oculomotor performance in mice.
通过视动反射和前庭眼反射（OKR和VOR）的联合作用，在自身运动过程中实现图像稳定。为了确定是否使用不同的神经元机制来校准由视觉和前庭信号驱动的眼球运动，我们研究了小鼠中OKR和VOR的发育成熟和适应性可塑性。用红外视频眼动图测量的OKR和VOR的联合性能，在成年小鼠和幼鼠（出生后21 - 26天）中都能产生近乎完美的注视稳定性。然而，对OKR和VOR单独进行分析表明，幼鼠的VOR增益低于成年小鼠，而OKR增益更高，这表明幼鼠比成年鼠更依赖视觉来稳定注视。小鼠OKR和VOR的适应性可塑性可由30分钟的视觉 - 前庭不匹配训练诱导产生。对训练对OKR和VOR的影响进行检查，揭示了适应性可塑性的不同机制和持续性。通过将小鼠向与视觉环境相反的方向旋转诱导的VOR增益增加是短暂的，同时OKR增益会伴随长期增加。相反，通过将小鼠向与视觉环境相同的方向旋转诱导的VOR增益降低是持久的，同时OKR增益也会伴随长期增加。前庭训练对OKR或VOR几乎没有影响，而视觉训练会诱导OKR产生强烈且持久的增加，但对VOR没有影响。这些数据表明，多种可塑性机制在不同的时间进程中起作用，以优化小鼠的眼球运动性能。
