Laboratory for Motor Learning Control, RIKEN Brain Science Institute, Hirosawa 2-1, Wako, Saitama 351-0198, Japan.
Neurosci Lett. 2011 Oct 17;504(1):53-6. doi: 10.1016/j.neulet.2011.08.056. Epub 2011 Sep 3.
Adaptation of mouse horizontal optokinetic response (HOKR) eye movement provides an experimental model for cerebellum-dependent motor learning. Our previous study revealed that the memory trace of HOKR adaptation is initially encoded in the cerebellar flocculus after hours of optokinetic training, and transferred to the vestibular nuclei to be consolidated to long-term motor memory after days of training [28]. To reveal how the cerebellar cortex operates in the transfer of the memory trace of adaptation, we examined the effects of shutdown of the cerebellar cortex after daily training. Three groups of mice received 1h of optokinetic training daily for 4 days, and showed similar amounts of adaptation after the end of 1h of training throughout 4 days. However, in the mice which daily received bilateral floccular muscimol infusion under gas anesthesia in the post-training period, consolidation of memory of the adaptation was markedly impaired, compared with the control mice which daily received bilateral floccular Ringer's solution infusions under gas anesthesia or those which daily received only gas anesthesia. These results are consistent with the studies of the effects of inactivation of cerebellar cortex on the consolidation of motor memory of rabbit eyeblink conditioning [2,4,18], and suggest that the post-training cerebellar cortex activity play an important for the consolidation of motor memory of HOKR adaptation.
适应鼠标水平视动反应（HOKR）眼球运动为小脑依赖运动学习提供了一个实验模型。我们之前的研究表明，HOKR 适应的记忆痕迹在数小时的视动训练后最初在小脑绒球中编码，并在数天的训练后转移到前庭核中，以巩固为长期运动记忆[28]。为了揭示小脑皮层在适应记忆痕迹转移中的作用，我们检查了每日训练后小脑皮层关闭的影响。三组小鼠每天接受 1 小时的视动训练，共 4 天，在 4 天的训练结束后，每天接受 1 小时的训练，其适应量相似。然而，在接受双侧绒球内注射麻醉后接受双侧绒球内注射麻醉的小鼠中，与每日接受双侧绒球内注射麻醉的对照小鼠或每日仅接受麻醉的小鼠相比，适应记忆的巩固明显受损。这些结果与小脑皮层失活对兔眨眼条件反射运动记忆巩固的影响研究一致[2、4、18]，表明训练后小脑皮层活动对 HOKR 适应运动记忆的巩固具有重要作用。
