Reorganization of Motor Cortex after Controlled Cortical Impact in Rats and Implications for Functional Recovery
Reorganization of Motor Cortex after Controlled Cortical Impact in Rats and Implications for Functional Recovery
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DOI：
10.1089/neu.2010.1456
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发表时间：
2010-12-01
影响因子：
4.2
通讯作者：
Nudo, Randolph J.
中科院分区：
文献类型：
--
作者：
Nishibe, Mariko;Barbay, Scott;Nudo, Randolph J.
我们报道了以大鼠运动皮质尾侧前肢区(CFA)为中心的受控皮质撞击(CCI)结果，以确定在备用皮质运动区(吻侧前肢区，RFA)检查皮质可塑性的可行性。我们比较了冲击器表面形状、大小和位置不同的三组CCI参数(CCI-1、CCI-2和CCI-3)对行为恢复和RFA结构和功能完整性的影响。在持续了35天的CCI后评估期间，通过熟练的伸展和足部失误任务评估的所有三个CCI组中，损伤对侧肢体的前肢缺陷都是明显的。Nissl染色的冠状切片显示RFA结构完整。在CCI后7周进行的皮质内微刺激实验证明RFA在功能上是可行的。然而，与对照组相比，CCI-1组的前肢代表的大小显著减少。将前肢近端的运动细分为不同的运动类型，存在显著的群体效应。RFA的面积缩小和重组分别与可能的失语和代偿性功能行为有关。此外，病变的前部范围和RFA的大小之间存在负相关，并讨论了与皮质连接的关系。结果表明，CCI可以应用于大鼠CFA，而不需要RFA。这一CCI模型有助于我们理解运动前皮质作为功能运动恢复底物的神经可塑性。
We report the results of controlled cortical impact (CCI) centered on the caudal forelimb area (CFA) of rat motor cortex to determine the feasibility of examining cortical plasticity in a spared cortical motor area (rostral forelimb area, RFA). We compared the effects of three CCI parameter sets (groups CCI-1, CCI-2, and CCI-3) that differed in impactor surface shape, size, and location, on behavioral recovery and RFA structural and functional integrity. Forelimb deficits in the limb contralateral to the injury were evident in all three CCI groups assessed by skilled reach and footfault tasks that persisted throughout the 35-day post-CCI assessment period. Nissl-stained coronal sections revealed that the RFA was structurally intact. Intracortical microstimulation experiments conducted at 7 weeks post-CCI demonstrated that RFA was functionally viable. However, the size of the forelimb representation decreased significantly in CCI-1 compared to the control group. Subdivided into component movement categories, there was a significant group effect for proximal forelimb movements. The RFA area reduction and reorganization are discussed in relation to possible diaschisis, and to compensatory functional behavior, respectively. Also, an inverse correlation between the anterior extent of the lesion and the size of the RFA was identified and is discussed in relation to corticocortical connectivity. The results suggest that CCI can be applied to rat CFA while sparing RFA. This CCI model can contribute to our understanding of neural plasticity in premotor cortex as a substrate for functional motor recovery.