Effects of exercise on motor functional recovery following collagenase-induced striatal hemorrhage in rats

本研究采用成年Wistar大鼠，通过左侧纹状体注射IV型胶原酶诱导脑出血（intra-cerebral hemorrhage，ICH）后运动功能的恢复，并研究跑台运动对ICH后运动功能的影响。脑出血导致脑穿通、脑室扩大和大脑皮质萎缩。运动组大鼠纹状体剩余面积和脑组织总面积与对照组无显著性差异。活动平板组脑出血后1 ~ 4周的MDS（运动缺陷评分）总评分低于对照组（仅脑出血），表明活动平板运动可改善运动功能障碍。尤其是前肢功能的改善最为显著。短期（脑出血后4天~ 14天）和长期（脑出血后4天~ 21天）运动对脑功能恢复的促进作用相同。另一方面，快速运动（13 m/min，在脑出血后8 ~ 14天）可能比慢速运动（9 m/min）更有效。脑出血后8周，同侧大脑皮质在运动前区/辅助运动区比对侧薄，初级运动区/躯体感觉运动区与前肢或后肢相关。在运动前区/辅助运动区，运动组的厚度显著大于对照组。我们还研究了皮质脊髓束（CST）的损害后，脑出血的逆行示踪剂，荧光金（FG）。结果表明，脑出血后，同侧皮质脊髓神经元中FG标记的神经元数量明显少于对侧，提示脑出血后皮质脊髓损伤。跑台运动不影响FG标记神经元的数量。活动平板运动可改善脑出血后运动功能。跑台运动可防止前运动区/辅助运动区的皮质收缩，该区域参与运动选择和运动输出的间接调节。这可能是运动恢复机制的一部分。

We investigated motor functional recovery following ICH(intra-cerebral hemorrhage), induced by injection of collagenase type IV into the left striatum in adult Wistar rats and researched on the effects of the treadmill exercise. ICH induced porencephaly, enlargement of ventricle and shrinkage of cerebral cortex. There were no significant differences in remaining striatal area and total brain tissue area between control and treadmill group. Total scores of MDS(motor deficit score) test from 1 to 4 weeks after ICH were low in treadmill group compared to control group (only ICH), indicating that disturbed motor function was improved by treadmill exercise. Especially, improvement of forelimb function was most remarkable. The effects, promoting functional recovery, of short-term treadmill exercise (4 days after ICH to 14 days) were same extent of long-term (4 days after ICH to 21 days). On the other, fast speed exercise (13 m/min, in 8 to 14 days after ICH) might be more effective than slow (9 m/min). At 8 weeks after ICH, ipsilateral cortex was thinner than contralateral one at premotor/supplementary motor area, and primary/somatosensory motor area correlated with forelimb or hindlimb. At premotor/supplementary motor area, the thickness in treadmill group was significantly thicker than that in control group. We also investigate the damage of corticospinal tract(CST) following ICH by a retrograde tracer, Fhioro-Gold(FG). At Very few corticospinal neurons were labeled by FG at ipsilateral cortex compared to contralateral, indicating the damage of CST induced by ICH. Treadmill exercise did not affect the number of FG labeled neurons. Data suggest that treadmill exercise could improve motor function after ICH. Treadmill exercise prevents cortical shrinkage at premotor/supplementary motor area, which participates in selection of movement and indirect regulation of motor output. This may form a part of the mechanisms of motor recovery.