Evolution of Gross Forelimb and Fine Digit Kinematics during Skilled Reaching Acquisition in Rats
Evolution of Gross Forelimb and Fine Digit Kinematics during Skilled Reaching Acquisition in Rats
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DOI：
10.1523/eneuro.0153-21.2021
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发表时间：
2021-09-01
期刊：
影响因子：
3.4
通讯作者：
Leventhal, Daniel K.
中科院分区：
文献类型：
--
作者：
Bova, Alexandra;Ferris, Kenneth;Leventhal, Daniel K.
学习灵巧运动技能的能力是人类行为的一个基本方面。然而，灵巧技能学习的潜在神经回路机制尚不清楚。推进我们对运动技能学习的理解需要将现代神经科学技术与严格表征的灵巧任务相结合。自动化的啮齿动物熟练达到爪子跟踪的发展，可以详细分析如何达到掌握运动学在学习过程中演变。我们评估了如何“粗”前肢和“细”手指运动学改变大鼠学习熟练的达到。成功率增加的大鼠（学习者）一致地减少了他们的到达轨迹的可变性。精细数字控制的改进通常在粗手工运输至颗粒稳定后继续进行。有趣的是，大多数大鼠的成功率没有增加（非学习者）也收敛于一致的达到运动学。然而，一些非学习者在整个训练过程中手和手指轨迹保持了很大的变化。这些结果表明，平均而言，灵巧技能的粗和精细运动组件是在不同的时间尺度上学习的。尽管如此，有显着的学科间的差异，在学习率的评估达到成功和一致性达到运动学。人类在很大程度上依赖于学习新的、灵巧的运动技能的能力。啮齿类动物的熟练伸手任务是研究灵巧技能学习的常用任务。然而，如何达到掌握运动学演变为大鼠学习熟练的达到还没有仔细的特点。通过结合自动化的啮齿动物熟练达到的任务与手和手指跟踪，我们发现显着的变化，成功率和手/手指运动学的演变。这种个体间的差异对于解释熟练触达研究是很重要的。此外，了解这种变异性的神经生物学基础可能有助于改善人类运动学习和康复。
The ability to learn dexterous motor skills is a fundamental aspect of human behavior. However, the underlying neural circuit mechanisms for dexterous skill learning are unclear. Advancing our understanding of motor skill learning requires the integration of modern neuroscientific techniques with a rigorously characterized dexterous task. The development of automated rodent skilled reaching with paw tracking allows detailed analysis of how reach-to-grasp kinematics evolve during learning. We assessed how both "gross" forelimb and "fine" digit kinematics changed as rats learned skilled reaching. Rats whose success rates increased (learners) consistently reduced the variability in their reach trajectories. Refinement of fine digit control generally continued after consistency in gross hand transport to the pellet plateaued. Interestingly, most rats whose success rates did not increase (non-learners) also converged on consistent reach kinematics. Some non-learners, however, maintained substantial variability in hand and digit trajectories throughout training. These results suggest that gross and fine motor components of dexterous skill are, on average, learned over different timescales. Nonetheless, there is significant intersubject variability in learning rates as assessed by both reaching success and consistency of reach kinematics. Significance Statement Humans depend heavily on the ability to learn novel, dexterous motor skills. The rodent skilled reaching task is commonly used to study dexterous skill learning. However, how reach-to-grasp kinematics evolve as rats learn skilled reaching has not been carefully characterized. By combining an automated rodent skilled reaching task with hand and digit tracking, we found significant variability in both success rates and the evolution of hand/digit kinematics. This interindividual variability is important for interpreting skilled reaching studies. Furthermore, understanding the neurobiologic basis of this variability may yield insights into improving human motor learning and rehabilitation.