RESTITUTION OF FUNCTION AND COLLATERAL SPROUTING IN CAT SPINAL-CORD - PARTIALLY HEMISECTED ANIMAL
RESTITUTION OF FUNCTION AND COLLATERAL SPROUTING IN CAT SPINAL-CORD - PARTIALLY HEMISECTED ANIMAL
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DOI：
10.1002/cne.901580103
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发表时间：
1974-01-01
影响因子：
2.5
通讯作者：
GOLDBERGER, ME
中科院分区：
文献类型：
--
作者：
MURRAY, M;GOLDBERGER, ME
侧支发芽可能与功能恢复相关的假设通过结合行为学和解剖学研究进行了验证。将猫脊髓T12~L11半切，保留背柱。最初，所有的反射和运动后肢活动同侧被压抑。在术后两周内，行为和肌电图反应增加的内在反射的启发，但不下降或交叉反射的启发。当内在反射活动增加时，肢体的使用明显改善，在某些情况下，肢体变得过度活跃。此后，这一状况稳定了10个月。由于内反射是由同侧背根介导的，因此，在半切后10个月或半切后20天通过定量放射自显影术测定L5或L6背根在椎管内的分布。两种方法均发现背根在脊髓灰质的分布不对称。实验侧的分布更大，Rexed椎板VI内侧和椎板VII外侧的分布更大。这些解剖学变化被认为是对同侧降束变性的反应，从背根发出侧支发芽的迹象。背根在背角（I-IV层）、运动核和薄束核的分布是对称的。背根输入的增加和扩大的区域可以与电生理学确定的皮肤反射和牵张反射促进路径中的中间神经元的位置相关。行为和解剖学的变化是选择性的，内反射恢复或变得过度活跃和同侧背根显示证据的侧支发芽在恢复期间，虽然两者之间的因果关系不能被证明，本实验。
The hypothesis that collateral sprouting might be correlated with recovery of function was tested by a combination of behavioral and anatomical studies. Partial hemisections, sparing the dorsal columns, were made between T12and L1of cat spinal cord. Initially, all reflex and locomotor hindlimb activity was depressed ipsilaterally. During two postoperative weeks behavioral and electromyographic responses increased in response to intrinsic reflex elicitation but not to descending or crossed reflex elicitation. Marked improvement in use of the limb occurred as intrinsic reflex activity increased and became, in some cases, hyperactive. The status then remained stable for ten months. Since intrinsic reflexes are mediated by ipsilateral dorsal roots, the intraspinal distribution of L5or L6dorsal roots was determined by degeneration methods ten months after hemisection or by quantitative radioautography 20 days after hemisection. By both methods, the dorsal root distribution was found to be asymmetrical in the spinal gray. It was greater on the experimental side and the distribution was altered, having a greater distribution medially in Rexed's lamina VI and laterally in lamina VII. These anatomical changes are considered as signs of collateral sprouting from dorsal roots in response to degeneration of descending tracts on the same side. Dorsal root distribution to dorsal horn (laminae I–IV), motor nuclei, and nucleus gracilis is symmetrical. Regions of increased and of expanded dorsal root input can be correlated with electrophysiologically determined location of interneurons in the path of cutaneous reflexes and of stretch reflex facilitation. Behavioral and anatomical changes were selective; intrinsic reflexes recovered or became hyperactive and ipsilateral dorsal roots showed evidence of collateral sprouting during the recovery period, although a causal relationship between the two cannot be proven, by the present experiments.