Gómez-Pinilla F, Villablanca J R, Sonnier B J, Levine M S
Brain Res. 1986 Oct 22;385(2):343-55. doi: 10.1016/0006-8993(86)91081-4.
This is a quantitative study of changes in distribution and density of terminals of the corticospinal tract in the cervical spinal cord and dorsal column nuclei (DCN) in cats with left cerebral hemispherectomy performed neonatally or in adulthood. Kittens received hemispherectomy at a mean of 12.1 postnatal days and were compared, as adults, to adult-lesioned cats of similar survival time. All animals, including controls, received injections of [3H]leucine-proline and were sacrificed 5 days later. Injection sites and terminal fields were reconstructed from autoradiography-processed tissue. The label filled comparable extents of areas 4 gamma and 3a of the right cerebral cortex. Coronal sections from upper and lower cervical cord levels, and from the brainstem (cuneate and gracile nuclei) were studied. Computer-image processing procedures were used to count labeled particles from multiple sites of the dorsal horn and DCN, bilaterally. In the spinal cord of intact and adult-hemispherectomized cats, most terminals were found in lamina VI, and adjacent laminae V and VII contralateral to the injection side. The major finding was that neonatal-lesioned cats showed a significant increase in axon terminals in areas ipsilateral to the injection. The topography of distribution of the novel terminals was similar to that in the contralateral side and the originating fibers appeared to have crossed the midline from that side. A similar reorganization occurred in the gracile nucleus where, in intact and adult-lesioned cats, the cortical terminals also predominated in the side contralateral to the injection. In contrast, neonatal-lesioned animals showed a significant increase in terminal density ipsilateral to the cortical injection. These findings are discussed as an alternative mechanism for postlesion remodeling of the corticospinal tract in animals with the pyramidal crossing completed at the time of birth.
这是一项关于新生期或成年期进行左侧大脑半球切除术的猫的颈脊髓和薄束核（DCN）中皮质脊髓束终末分布和密度变化的定量研究。小猫在出生后平均12.1天接受半球切除术，并在成年后与存活时间相似的成年损伤猫进行比较。所有动物，包括对照组，均接受[3H]亮氨酸 - 脯氨酸注射，并在5天后处死。从经放射自显影处理的组织中重建注射部位和终末场。标记物填充了右侧大脑皮质4γ区和3a区相当的范围。研究了颈脊髓上下水平以及脑干（楔束核和薄束核）的冠状切片。使用计算机图像处理程序从双侧背角和薄束核的多个部位计数标记颗粒。在完整和成年半球切除猫的脊髓中，大多数终末位于注射侧对侧的VI层以及相邻的V层和VII层。主要发现是新生期损伤的猫在注射同侧区域的轴突终末显著增加。新终末的分布地形与对侧相似，并且起源纤维似乎从该侧穿过中线。在薄束核中也发生了类似的重组，在完整和成年损伤的猫中，皮质终末也在注射侧对侧占主导。相比之下，新生期损伤的动物在皮质注射同侧的终末密度显著增加。这些发现被讨论为出生时锥体交叉已完成的动物中皮质脊髓束损伤后重塑的一种替代机制。
