Repetitive visual stimulation is successfully used in a study on the visual evoked potential (VEP) plasticity in the visual system in mammals. Practicing visual tasks or repeated exposure to sensory stimuli can induce neuronal network changes in the cortical circuits and improve the perception of these stimuli. However, little is known about the effect of visual training at the subcortical level. In the present study, we extend the knowledge showing positive results of this training in the rat’s Superior colliculus (SC). In electrophysiological experiments, we showed that a single training session lasting several hours induces a response enhancement both in the primary visual cortex (V1) and in the SC. Further, we tested if collicular responses will be enhanced without V1 input. For this reason, we inactivated the V1 by applying xylocaine solution onto the cortical surface during visual training. Our results revealed that SC’s response enhancement was present even without V1 inputs and showed no difference in amplitude comparing to VEPs enhancement while the V1 was active. These data suggest that the visual system plasticity and facilitation can develop independently but simultaneously in different parts of the visual system.

中文翻译：

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皮质失活不会阻碍上丘的反应增强


重复视觉刺激已成功用于哺乳动物视觉系统视觉诱发电位（VEP）可塑性的研究。练习视觉任务或反复接触感觉刺激可以诱发皮质回路中的神经元网络变化，并改善对这些刺激的感知。然而，人们对皮层下视觉训练的效果知之甚少。在本研究中，我们扩展了知识，显示了这种训练在大鼠上丘（SC）中的积极效果。在电生理学实验中，我们表明，持续几个小时的单次训练会引起初级视觉皮层 (V1) 和 SC 的反应增强。此外，我们测试了在没有 V1 输入的情况下是否会增强丘脑反应。因此，我们在视觉训练期间通过将利多卡因溶液涂抹到皮质表面来灭活 V1。我们的结果表明，即使没有 V1 输入，SC 的响应增强也存在，并且与 V1 激活时的 VEP 增强相比，幅度没有差异。这些数据表明，视觉系统的可塑性和易化性可以在视觉系统的不同部分独立但同时发展。