Reinoso B S, Castro A J
Department of Anatomy, Loyola University Stritch School of Medicine, Maywood, IL 60153.
Exp Brain Res. 1989;74(2):387-94. doi: 10.1007/BF00248872.
The retrogradely transported fluorescent tracers Fast Blue (FB) and Diamidino Yellow (DY) were injected into the spinal cord of adult rats that sustained unilateral frontoparietal cortical lesions at birth. Analysis of the resulting cortical labeling pattern in comparison to comparably injected control animals demonstrated an increase of retrogradely-labeled neurons within the unablated cerebral hemisphere ipsilateral to spinal cord injections. These ipsilateral labeled cells corresponded to previous descriptions, based on anterograde tracing techniques, of anomalous uncrossed corticospinal tract (CST) fibers. Additional findings indicated that the ipsilateral CST fibers are not axonal collaterals of normal, crossed CST fibers. Fluorescent tracer injections into cervical and lumbar spinal cord levels demonstrated a distribution pattern of labeled cells within the ipsilateral cortex that was similar to the topographic pattern found contralateral to spinal cord injections in normal animals. These findings support previous anatomical and electrophysiological data indicating that the neonatal cortical lesion-induced increase of ipsilateral CST fibers may be functional.
将逆行运输的荧光示踪剂快蓝（FB）和双脒基黄（DY）注射到出生时遭受单侧额顶叶皮质损伤的成年大鼠脊髓中。与同等注射的对照动物相比，对由此产生的皮质标记模式进行分析，结果显示在脊髓注射同侧未受损的大脑半球内，逆行标记的神经元有所增加。这些同侧标记细胞与基于顺行追踪技术对异常未交叉皮质脊髓束（CST）纤维的先前描述相符。其他研究结果表明，同侧CST纤维不是正常交叉CST纤维的轴突侧支。向颈段和腰段脊髓水平注射荧光示踪剂，结果显示同侧皮质内标记细胞的分布模式与正常动物脊髓注射对侧所发现的地形模式相似。这些研究结果支持了先前的解剖学和电生理学数据，表明新生儿皮质损伤引起的同侧CST纤维增加可能具有功能。
