Ernster Alayna E, Park Seoung Hoon, Yacoubi Basma, Christou Evangelos A, Casamento-Moran Agostina, Singer Michele L, Humbert Ianessa A
Swallowing Systems Core, Department of Speech, Language and Hearing Sciences, University of Florida, Gainesville, FL, United States.
Neuromuscular Physiology Laboratory, Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, United States.
Physiol Behav. 2018 Jul 1;191:155-161. doi: 10.1016/j.physbeh.2018.04.016. Epub 2018 Apr 17.
There are multiple descending neural pathways, including the corticospinal pathway (CS) and the corticobulbar pathway (CB). The corticospinal pathway has been shown to exhibit within-pathway (CS-to-CS) motor transfer. However, motor transfer across each pathway (CS-to-CB or CB-to-CS) has yet to be studied in depth. The aim of the present study was to examine the effects of cross-pathway motor transfer between the ankle (CS) and tongue (CB) after training with a ballistic goal-directed motor task. Twelve healthy participants were recruited for this two-day experimental study. Six participants performed a ballistic goal-directed task with their ankle on Day 1 (ankle dorsiflexion), then tongue on Day 2 (elevate tongue against IOPI). The other 6 participants performed the same task with their tongue on Day 1, then ankle on Day 2. Both the ankle and tongue tasks (50 trials each) required matching force and time to a visual target. Our findings indicate that participants who underwent ankle training on Day 1 exhibited decreased tongue force error on Day 2 compared with participants who completed the tongue training on Day 1, with no prior ankle training (p = 0.02) (i.e. greater accuracy). This finding suggests that cross-pathway transfer from the corticospinal pathway to the corticobulbar pathway occurred with respect to force error. In other words, training of the ankle (CS) translated to improved training performance of the tongue (CB) through a reduction in force error. However, the reverse was not true - training the tongue did not elicit improved performance of the ankle. Nonetheless, if training with the corticospinal pathway can lead to improved corticobulbar pathway functioning, incorporating multi-pathway rehabilitation techniques might be valuable for clinicians across medical disciplines.
存在多条下行神经通路，包括皮质脊髓束（CS）和皮质延髓束（CB）。研究表明，皮质脊髓束内存在通路内（CS到CS）的运动转移。然而，各通路间（CS到CB或CB到CS）的运动转移尚未得到深入研究。本研究的目的是在进行弹道式目标导向运动任务训练后，检查踝关节（CS）和舌头（CB）之间跨通路运动转移的效果。12名健康参与者被招募参加这项为期两天的实验研究。6名参与者在第1天用踝关节进行弹道式目标导向任务（踝关节背屈），然后在第2天用舌头进行（对抗IOPI抬起舌头）。另外6名参与者在第1天用舌头进行相同任务，然后在第2天用踝关节进行。踝关节和舌头任务（各50次试验）都需要将力量和时间与视觉目标匹配。我们的研究结果表明，与第1天完成舌头训练但之前没有踝关节训练的参与者相比，第1天接受踝关节训练的参与者在第2天表现出舌头力量误差降低（p = 0.02）（即更高的准确性）。这一发现表明，就力量误差而言，发生了从皮质脊髓束到皮质延髓束的跨通路转移。换句话说，踝关节（CS）的训练通过减少力量误差转化为舌头（CB）训练表现的改善。然而，反之则不然——训练舌头并没有使踝关节表现得到改善。尽管如此，如果皮质脊髓束的训练能够导致皮质延髓束功能的改善，那么纳入多通路康复技术可能对各医学学科的临床医生都有价值。
