Shu Liang, Dong You-Rong, Yan Wei-Hong, Zhai Yu, Wang Yun, Li Wei
Shanghai Ninth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China.
Sheng Li Xue Bao. 2011 Aug 25;63(4):291-9.
Sciatic nerve injury is a common disease of peripheral nerve in clinic. After nerve injury, there are many dysfunctions in motoneurons and muscles following regeneration. Previous studies mostly investigated the aspects related to the injured nerve, and the effect on the recurrent inhibition (RI) pathway of spine following regeneration was not fully understood. Following reinnervation after temporary sciatic nerve crush, the functional alteration of RI was studied. In adult rats, RI between lateral gastrocnemius-soleus (LG-S) and medial gastrocnemius (MG) motor pools was assessed by conditioning monosynaptic reflexes (MSRs) elicited from the cut dorsal roots and recorded from either the LG-S or MG nerves by antidromic stimulation of the synergist muscle nerve. The following results were obtained. (1) The RI of MSRs in rats was almost lost (<5 weeks) after sciatic nerve crush. Although the RI partially recovered following reinnervation (6 weeks), it remained permanently depressed (up to 14 weeks). (2) Sciatic nerve crush on one side did not affect the contralateral RI. (3) Sciatic nerve crush did not induce any motoneuron loss revealed by immunohistochemistry. Peripheral nerve temporary disconnection causes long term alterations in RI pathway which make up motoneuron's function enhance for the alteration of muscle power and suggests that peripheral nerve injury induces long term plastic changes in the spinal motoneuron circuitry.
坐骨神经损伤是临床上常见的周围神经疾病。神经损伤后，运动神经元和肌肉在再生后会出现许多功能障碍。以往的研究大多集中在与受损神经相关的方面，而对再生后脊髓回返抑制（RI）通路的影响尚未完全了解。在坐骨神经暂时挤压后重新神经支配后，研究了RI的功能改变。在成年大鼠中，通过刺激切断的背根诱发单突触反射（MSR），并通过对协同肌神经的逆向刺激从外侧腓肠肌-比目鱼肌（LG-S）或内侧腓肠肌（MG）神经记录，评估LG-S和MG运动池之间的RI。获得了以下结果。（1）坐骨神经挤压后，大鼠MSR的RI在5周内几乎丧失。虽然重新神经支配后RI部分恢复（6周），但仍持续降低（长达14周）。（2）一侧坐骨神经挤压不影响对侧RI。（3）坐骨神经挤压未引起免疫组织化学显示的任何运动神经元丢失。周围神经暂时切断会导致RI通路的长期改变，这使得运动神经元的功能因肌肉力量的改变而增强，表明周围神经损伤会引起脊髓运动神经元回路的长期可塑性变化。
