Titley Heather K, Heskin-Sweezie Raquel, Broussard Dianne M
Department of Physiology, University of Toronto, Toronto, Ontario, Canada.
Brain Res. 2009 Apr 24;1267:37-43. doi: 10.1016/j.brainres.2009.02.041. Epub 2009 Mar 5.
The vestibulo-ocular reflex (VOR) exhibits motor learning that initially depends on synaptic plasticity in the cerebellar cortex. Learned decreases in VOR gain can be disrupted by rotation in darkness immediately following learning, but consolidate rapidly if the disruption stimulus is delayed. Disruption may simply reverse the synaptic changes that have recently occurred, or it may reflect new learning at other sites. The alternative to disruption, rapid consolidation, also may take place by altering the existing memory trace or may require changes at other locations. To test these possibilities, we induced decreases in the gain of the VOR in cats that wore miniaturizing goggles. Using a range of frequencies of rotation, we investigated the patterns of generalization for disruption and for rapid consolidation of the learned changes in gain. Learning was most effective at the particular frequencies that were used during training. However, disruption and rapid consolidation were not more effective at the rotation frequencies that were used during training. Instead, after consolidation, the memory retained the frequency tuning that had been established during the learning process. We conclude that disruption and rapid consolidation may not require new learning.
前庭眼反射(VOR)表现出运动学习,其最初依赖于小脑皮质中的突触可塑性。学习引起的VOR增益降低在学习后立即于黑暗中旋转时会受到干扰,但如果干扰刺激延迟,则会迅速巩固。干扰可能只是逆转了最近发生的突触变化,也可能反映了其他部位的新学习。与干扰相反,快速巩固也可能通过改变现有的记忆痕迹发生,或者可能需要其他部位发生变化。为了测试这些可能性,我们在佩戴微型护目镜的猫身上诱导VOR增益降低。使用一系列旋转频率,我们研究了干扰和学习到的增益变化快速巩固的泛化模式。学习在训练期间使用的特定频率下最为有效。然而,干扰和快速巩固在训练期间使用的旋转频率下并不更有效。相反,巩固后,记忆保留了学习过程中建立的频率调谐。我们得出结论,干扰和快速巩固可能不需要新的学习。