Miklyaeva E I, Varlinskaya E I, Ioffe M E, Mats V N, Pokazanyeva L N, Kulikov M A
Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow.
Behav Brain Res. 1993 Sep 30;56(2):145-54. doi: 10.1016/0166-4328(93)90032-l.
After ablation of the motor cortex contralateral to the preferred limb, rats were forced to use this limb in grasping food out of a horizontal tube by restraining the non-preferred foreleg with a bracelet. In a right-handed rat the motor behaviour is less impaired and the recovery is better after a left hemisphere lesion in comparison with a left-handed rat after a right hemisphere lesion. This difference is primarily the time needed to use the limb in reaching for seed (testperiod 3) and the total time needed for 10 successive seizings of seed (testperiod 5). Surprisingly, the differences in the course of recovery do not correlate with the degree of preoperative limb preference: the initially ambidextrous rate also show the same differences in results of the motor cortex ablation in left and right hemisphere. However, in the group of initially consistent ambidextrous rats, after 10 weeks of tests with a restrained forelimb, the testing under unrestrained free conditions shows a gradual decrease in the induced limb preference and a shift to the use of the foreleg contralateral to the intact hemisphere, while in contrast the initially consistent left- or right-handed rats preserve the limb preference under the unrestrained testing conditions. Therefore the degree of initial preference still influences the choice of limb after motor cortex ablation and intensive training to use the 'damaged' limb.
在对偏好肢体对侧的运动皮层进行切除后，通过用手环束缚非偏好前肢，迫使大鼠用该肢体从水平管中抓取食物。与右半球损伤后的左利手大鼠相比，右利手大鼠在左半球损伤后运动行为受损较轻且恢复较好。这种差异主要体现在抓取种子时使用该肢体所需的时间（测试期3）以及连续10次抓取种子所需的总时间（测试期5）。令人惊讶的是，恢复过程中的差异与术前肢体偏好程度无关：最初双手灵活的大鼠在左、右半球运动皮层切除结果中也表现出相同的差异。然而，在最初一直双手灵活的大鼠组中，在用束缚前肢进行10周测试后，在无束缚的自由条件下测试显示，诱导的肢体偏好逐渐降低，并转向使用与完整半球对侧的前肢，而相比之下，最初一直左利手或右利手的大鼠在无束缚测试条件下保持肢体偏好。因此，初始偏好程度仍然会影响运动皮层切除后以及使用“受损”肢体的强化训练后的肢体选择。
