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

本实验观察了成年Wistar大鼠左侧纹状体内注射IV型胶原酶诱发脑出血后运动功能的恢复，并研究了跑台运动的作用。ICH可致小鼠脑空洞、脑室增大、大脑皮质缩小。对照组与跑台组剩余纹状体面积和总脑组织面积差异无统计学意义。运动功能障碍评分(MDS)总分在脑出血后1~4周跑台组明显低于对照组(仅限于脑出血组)，提示运动功能障碍得到了改善。尤其是前肢功能改善最为显著。短期平板运动(脑出血后4天至14天)对功能恢复的促进作用与长期跑台运动(脑出血后4天至21天)相同。另一方面，快速度运动(13m/min，在脑出血后8~14d)可能比慢速运动(9m/min)更有效。脑出血后8周，运动前/辅助运动区同侧皮质较对侧薄，主/体感运动区与前肢或后肢相关。在运动前/辅助运动区，跑台组较对照组明显增厚。我们还研究了逆行示踪剂Fhioro-Gold(FG)对脑出血后皮质脊髓束(CST)的损害。FG标记的皮质脊髓神经元在同侧皮质较对侧少，提示脑出血对CST的损伤。跑台运动不影响FG标记神经元的数量。数据表明，跑步机运动可以改善脑出血后的运动功能。跑步机运动可防止运动前/辅助运动区的皮质收缩，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.