Darling Warren G, Morecraft Robert J, Rotella Diane L, Pizzimenti Marc A, Ge Jizhi, Stilwell-Morecraft Kimberly S, Zhang Hongyu, Soliman Hesham, Seecharan Dave, Edwards Ian, McNeal David, Nudo Randolph J, Cheney Paul
Department of Health and Human Physiology, University of Iowa, Iowa City, IA, USA,
Exp Brain Res. 2014 Dec;232(12):3929-38. doi: 10.1007/s00221-014-4068-9. Epub 2014 Aug 28.
We investigated recovery of precision grasping of small objects between the index finger and thumb of the impaired hand without forced use after surgically placed lesions to the hand/arm areas of M1 and M1 + lateral premotor cortex in two monkeys. The unilateral lesions were contralateral to the monkey's preferred hand, which was established in prelesion testing as the hand used most often to acquire raisins in a foraging board (FB) task in which the monkey was free to use either hand to acquire treats. The lesions initially produced a clear paresis of the contralesional hand and use of only the ipsilesional hand to acquire raisins in the FB task. However, beginning about 3 weeks after the lesion both monkeys spontaneously began using the impaired contralesional hand in the FB task and increased use of that hand over the next few tests. Moreover, the monkeys clearly used precision grasp to acquire the raisins in a similar manner to prelesion performances, although grasp durations were longer. Although the monkeys used the contralesional hand more often than the ipsilesional hand in some postlesion testing sessions, they did not recover to use the hand as often as in prelesion testing when the preferred hand was used almost exclusively. These findings suggest that recovery of fine hand/digit motor function after localized damage to the lateral frontal motor areas in rhesus monkeys does not require forced use of the impaired hand.
我们研究了两只猴子在对初级运动皮层(M1)和M1+外侧运动前皮层的手部/臂部区域进行手术损伤后,受损手的食指和拇指之间对小物体精确抓握的恢复情况,且没有强制使用受损手。单侧损伤位于猴子优势手的对侧,在损伤前测试中确定优势手是猴子在觅食板(FB)任务中最常用来获取葡萄干的手,在该任务中猴子可以自由使用任一只手获取食物。损伤最初导致对侧手明显麻痹,在FB任务中猴子仅用同侧手获取葡萄干。然而,在损伤后约3周,两只猴子开始在FB任务中自发使用受损的对侧手,并在接下来的几次测试中增加了该手的使用频率。此外,猴子明显以与损伤前相似的方式使用精确抓握来获取葡萄干,尽管抓握持续时间更长。虽然在损伤后的一些测试中,猴子使用对侧手的频率高于同侧手,但它们并未恢复到损伤前测试时几乎只使用优势手的频率。这些发现表明,恒河猴外侧额叶运动区局部损伤后,精细手部/手指运动功能的恢复并不需要强制使用受损手。