Background Stroke is a leading cause of disability worldwide. Focused training of the impaired limb has been shown to improve its functional outcome in animal models. However, most human stroke survivors exhibit persistent motor deficits, likely due to differences in rehabilitation intensity between experimental (animal) and clinical (human) settings. Objective The current study investigated the effect of training intensity on behavioral outcome in a mouse model of stroke. Methods Mice were trained preoperatively on a skilled reaching task. After training, mice received a unilateral photothrombotic stroke. Postoperatively, animals received either daily rehabilitative training (traditional intensity), intermittent rehabilitative training (every other day), or no rehabilitative training (control). Assessment of the impaired limb occurred after 14 training sessions (14 days for the Traditional group; 28 days for the Intermittent group). Results Assessment of the impaired limb illustrated that traditional, daily training resulted in significantly better performance than no training, while intermittent training offered moderate performance gains. Mice receiving intermittent training performed significantly better than control mice but did not exhibit reaching performance as strong as that of animals trained daily. Conclusions The intensity of rehabilitation is important for optimal recovery. Although intermediate intensity offers some benefit, it is not intensive enough to mimic the performance gains traditionally observed in animal models. These results suggest that intensive training, which is often unavailable for human stroke survivors, is necessary to achieve an optimal functional outcome. The lower bounds of training intensity for functional benefit still need to be determined.

中文翻译：

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间歇性技能训练可适度改善缺血性中风小鼠模型的功能结果

背景 中风是世界范围内导致残疾的主要原因。在动物模型中，对受损肢体的集中训练已被证明可以改善其功能结果。然而，大多数人类中风幸存者表现出持续的运动缺陷，这可能是由于实验（动物）和临床（人类）环境之间康复强度的差异。目的目前的研究调查了训练强度对中风小鼠模型行为结果的影响。方法 术前对小鼠进行熟练到达任务的训练。训练后，小鼠接受单侧光血栓形成中风。术后，动物接受每日康复训练（传统强度）、间歇性康复训练（每隔一天）或不接受康复训练（对照）。在 14 次训练课程（传统组 14 天；间歇组 28 天）后对受损肢体进行评估。结果 对受损肢体的评估表明，传统的日常训练比不训练显着提高了表现，而间歇性训练则提供了适度的表现提升。接受间歇训练的小鼠表现明显优于对照小鼠，但没有表现出与每天训练的动物一样强的表现。结论 康复强度对于最佳恢复很重要。尽管中等强度提供了一些好处，但强度不足以模拟传统上在动物模型中观察到的性能提升。这些结果表明，人类中风幸存者通常无法进行强化训练，是实现最佳功能结果所必需的。仍然需要确定功能益处的训练强度下限。