Disuse of the paretic hand after stroke is encouraged by compensatory reliance on the nonparetic hand, to exacerbate impairment and potentially constrain motor rehabilitation efficacy. Rodent stroke model findings support that learning new unimanual skills with the nonparetic forelimb diminishes functional improvements that can be driven by rehabilitative training of the paretic forelimb. The influence of learning new ways of skillfully using the two hands together on paretic side function is much less clear. To begin to explore this, we developed a new cooperative bimanual skilled reaching task for rats, the Popcorn Retrieval Task. After motor cortical infarcts impaired an established unimanual reaching skill in the paretic forelimb, rats underwent a 7 week period of de novo bimanual training (BiT) or no-training control procedures (Cont). Probes of paretic forelimb unimanual performance revealed significant improvements during and after the training period in BiT vs. Cont. We additionally observed a striking change in the bimanual task strategy over training days: a switch from the paretic to the nonparetic forelimb for initiating reach-to-grasp sequences. This motivated another study to test whether rats that established the bimanual skill prior to the infarcts would similarly switch handedness, which they did not, though paretic paw use for manipulative movements diminished. These results indicate that unimanual function of the paretic side can be improved by novel bimanual skill practice, even when it involves compensatory reliance on the nonparetic hand. They further support the suitability of the Popcorn Retrieval Task for studying bimanual skill learning effects in rats.

对非瘫痪手的代偿性依赖鼓励中风后停用瘫痪手，以加剧损伤并可能限制运动康复效果。啮齿动物中风模型研究结果支持非瘫痪前肢学习新的单手技能会减少功能改善，而功能改善可以通过对瘫痪前肢的康复训练来推动。学习巧妙地同时使用两只手的新方法对麻痹侧功能的影响尚不清楚。为了开始探索这一点，我们为老鼠开发了一种新的合作双手熟练到达任务，爆米花检索任务。在运动皮层梗塞损害了麻痹前肢既定的单手触及技能后，大鼠经历了 7 周的从头运动双手训练（BiT）或无训练控制程序（续）。对麻痹前肢单手操作的探测显示在 BiT 与 Cont 的训练期间和之后有显着改善。我们还观察到训练日期间双手任务策略的显着变化：从麻痹的前肢切换到非麻痹的前肢，以启动伸手抓握序列。这激发了另一项研究，以测试在梗塞之前建立双手技能的大鼠是否会类似地转换惯用手，但他们没有这样做，尽管用于操纵运动的麻痹爪子减少了。这些结果表明，即使涉及对非瘫痪手的代偿性依赖，新的双手技能练习也可以改善瘫痪侧的单手功能。