Reinnervation of denervated skeletal muscle by central neurons regenerating via ventral roots implanted into the spinal cord.
Reinnervation of denervated skeletal muscle by central neurons regenerating via ventral roots implanted into the spinal cord.
复制标题
通过植入脊髓的腹侧根再生的中枢神经元对去神经骨骼肌进行神经再支配。
DOI：
10.1016/0006-8993(91)90936-p
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发表时间：
1991
期刊：
影响因子：
2.9
通讯作者：
Kodama,RT
中科院分区：
文献类型：
--
作者：
Smith,KJ;Kodama,RT
在大鼠脊髓内观察了经腹根再生的中枢轴突对失神经骨骼肌的再支配作用。将第8只胸椎前根切断，并将其远端植入脊髓腹外侧柱。对照组动物的牙根被切断，但没有被植入到刺伤的伤口中。12-14个月后，对动物进行电生理学检查，以确定第8肋间肌肉中运动单位的存在或缺失，这些运动单位由通过植入物再生的中央来源的轴突重新支配。在植入的动物中发现了这样的单位，但没有在对照组中发现。中枢轴突重新支配运动单位的证据包括：(1)通过电刺激背根或脊髓反射性地(即跨突触地)激活运动单位，或(2)通过脊髓内注射谷氨酸或乙酰胆碱，或通过全身给药士的宁来激活运动单位。非常小心地确保脊髓与第8肋间肌之间的唯一可行连接是通过植入部位。来自运动单位的EMG信号幅度大，是典型的神经支配肌肉，它们的单独激活导致T8肋间肌区域明显收缩。我们的结论是，通过将切断的腹根植入脊髓，再生的中枢神经系统神经元可以被引导到失神经骨骼肌神经支配。形成的神经肌肉突触具有功能性和持久性。这一发现可能与神经损伤后功能的恢复有关，例如腹根撕脱。
The reinnervation of denervated skeletal muscle by central axons regenerating via a ventral root implanted into the spinal cord was examined in rats. The 8th thoracic ventral root was severed and its distal end implanted into the ventro-lateral column of the spinal cord via a stab incision. In control animals the root was severed, but was not implanted into the stab incision. After 12–14 months the animals were examined electrophysiologically to determine the presence or absence of motor units in the 8th intercostal muscle which were reinnervated by centrally derived axons regenerating via the implant. Such units were found in implanted animals, but in none of the controls. Evidence that the motor units were reinnervated by central axons included the facts that the units could be activated either, (1) reflexly (i.e. trans-synaptically) by electrical stimulation of the dorsal roots or spinal cord, or (2) pharmacologically by either the intraspinal injection of glutamate or acetylcholine, or by the systemic administration of strychnine. Great care was taken to ensure that the only feasible connection between the spinal cord and the 8th intercostal muscle was via the site of implantation. The EMG signals from the motor units were of large amplitude, typical of reinnervated muscle, and their individual activation resulted in discernible contractions of regions of the T8intercostal muscle. We conclude that regenerating CNS neurons can be guided to innervat denervated skeletal muscle by the implantation of severed ventral roots into the spinal cord. The neuromuscular synapses formed are functional and persistent. The findings may be relevant to the restoration of function after nervous injuries, such as the avulsion of ventral roots.