Motor endplate is the structure connected between the nerve terminal and muscle fibre and plays a very important role in conducting nerve impulses to the target, therefore, systemical study of the sequential changes of the motor end-plate upon denervation is quite important.Ninety New Zealand rabbits were divided into nine groups from two weeks to nine months after denervation. Acetycholinesterase(AchE) was analyzed quantitatively to study the sequential changes of the motorendplates of tibialis anterior muscle. The results showed that there was no significant reduction of AchE at theend if one month after denervation, whereas a sharp reduction of AchE afterwards. AchE could not be stained after five month denervation.
OBJECTIVE Following the delayed repair of peripheral nerve injury, the cell number of anterior horn of the spinal cord and its ultrastructural changes, motorneuron and its electrophysiological changes were investigated. METHODS In 16 rabbits the common peroneal nerves of both sides being transected one year later were divided into four groups randomly: the degeneration group and regeneration of 1, 3 and 5 months groups. Another 4 rabbits were used for control. All transected common peroneal nerves underwent epineural suture except for the degeneration group the electrophysiological examination was carried out at 1, 3 and 5 months postoperatively. Retrograde labelling of the anterior horn cells was demonstrated and the cells were observed under light and electronmicroscope. RESULTS 1. The number of labelled anterior horn cell in the spinal cord was 45% of the normal population after denervation for one year (P lt; 0.01). The number of labelled cells increased steadily from 48% to 57% and 68% of normal values at 1, 3 and 5 months following delayed nerve repair (P lt; 0.01). 2. The ultrastructure of the anterior horn cells of the recover gradually after repair. 3. With the progress of regeneration the latency become shortened, the conduction velocity was increased, the amplitude of action potential was increased. CONCLUSION Following delayed repair of injury of peripheral nerve, the morphology of anterior horn cells of spinal cord and electrophysiological display all revealed evidence of regeneration, thus the late repair of injury of peripheral nerve was valid.
Objective To review researches of treatment of peripheral nerve injury with neuromuscular electrical stimulation (NMES) regarding mechanism, parameters, and cl inical appl ication at home and abroad. Methods The latest original l iterature concerning treatment of peri pheral nerve injury with NMES was extensively reviewed. Results NMES should be used under individual parameters and proper mode of stimulation at early stage of injury. It could promote nerve regeneration and prevent muscle atrophy. Conclusion NMES plays an important role in cl inical appl ication of treating peripheral nerve injury, and implantable stimulation will be the future.
OBJECTIVE: To observe the functional rehabilitation of injured peripheral nerve with electric acupuncture. METHODS: Sciatic nerve injury model was established by transection of left sciatic nerve in 60 Wistar rats, which were randomly divided into two groups. The experimental group was treated with electroacupuncture, no treatment in the control group. Change of nerve electrophysiological, power of muscle and sciatic functional index (SFI) were observed. RESULTS: Nerve muscle-action potential (MAP) and motor nerve conduction velocity (MNCV) in the experimental group were better than that of the control group (P lt; 0.01). The single muscle twitch and tetanization of gastrocnemius muscle were higher in the experimental group too (P lt; 0.05). SFI were significantly higher in the experimental group (P lt; 0.05). CONCLUSION: Electric acupuncture therapy can improve functional rehabilitation of injured peripheral nerve.
Objective To observe the histomorphology and the biocompatibil ity of acellular nerve prepared by different methods, to provide the experimental evidence for the selection of preparation of acellular nerve scaffold. Methods Forty-eight adult Sprague Dawley rats, male or female, weighing 180-220 g, were selected. The sciatic nerves were obtained from 30 rats and were divided into groups A, B, and C (each group had 20 nerves). The acellular sciatic nerves were prepared by the chemical methods of Dumont (group A), Sondell (group B), and Haase (group C). The effect to remove cells was estimated by the degree of decellularization, degree of demyel ination, and intergrity of nerve fiber tube. The histocompatibil ity was observed by subcutaneous implant test in another 18 rats. Three points were selected along both sides of centre l ine on the back of rats, and the points were randomly divided into groups A1, B1, and C1; the acellular nerve of groups A, B, and C were implanted in the corresponding groups A1, B1, and C1. At 1, 2, and 4 weeks after operation, the rats were sacrificed to perform the general observation and histological observation. Results The histomorphology: apart of cells and the dissolved scraps of axon could be seen in acellular never in the group A, and part of Schwann cell basilar membrane was broken. In group B, the cells in the acellular never were not removed completely, the Schwann cell basilar membrane formed bigger irregular hollows, part of the Schwann cell basilar membrane was broken obviously. But in the group C, the cells were completely removed, the Schwann cell basilar membrane remained intactly. Group C was better than group A and group B in the degree of decellularization, degree of demyel ination, integrity of nerve fiber tube and total score, showing significant differences (P lt; 0.05). The subcutaneous implant test: there were neutrophils and lymphocytes around the acellular nerve in 3 groups at 1 week after implant. A few of lymphocytes were observed around the acellular nerve in 3 groups at 2 weeks after implant. The inflammation was less in groups A1, B1, and C1 at 4 weeks after implant, part of the cells grew into the acellular nerve and arranged along the Schwann cell basilar membrane. The reaction indexes of the inflammational cells in group A1 and group B1 were higher than that in group C1 at 1, 2, and 4 weeks after implant, showing significant differences (P lt; 0.01), but there was no significant difference between group A1 and group B1 (P gt; 0.05). Conclusion The acellular sciatic nerves prepared by Haase method has better acellular effect and the histocompatibil ity than those by the methods of Dumont and Sondell.
OBJECTIVE: To investigate the protective effect of tumor necrosis factor-alpha(TNF-alpha) on spinal motor neurons after peripheral nerve injury. METHODS: Twenty Wistar rats were divided into two groups, the right sciatic nerves of 20 Wistar rats were transected, the proximal stumps were inserted into a single blind silicone tube. 16 microliters of normal saline(NS) and TNF-alpha(30 U/ml) were injected into the silicone tubes. After 2 weeks, the 4th, 5th lumbar spinal cord were taken for examination. Enzyme histochemical technique and image analysis were used to show acetylcholinesterase(AChE) and nitric oxide synthase(NOS) activity of spinal motor neurons. RESULTS: The number of AChE and NOS staining neurons were 8.65 +/- 1.98 and 5.92 +/- 1.36 in the experimental group and 6.37 +/- 1.42 and 8.67 +/- 1.45 in the control group respectively, there were significant difference between the two groups(P lt; 0.01). CONCLUSION: It suggests that TNF-alpha has protective effect on motor neurons after peripheral nerve injury.
Objective To observe the delaying effect of neural stem cell (NSC) transplantation on denervated muscle atrophy after peri pheral nerve injury, and to investigate its mechanism. Methods NSCs were separated from the spinal cords of green fluorescent protein (GFP) transgenic rats aged 12-14 days mechanically and were cultured and induced to differentiate in vitro. Thirty-two F344 rats, aged 2 months and weighed (180 ± 20) g, were randomized into two groups (n=16 per group). The animal models of denervated musculus triceps surae were establ ished by transecting right tibial nerve and commom peroneal nerve 1.5 cm above the knee joints. In the experimental and the control group, 5 μL of GFP-NSCsuspension and 5 μL of culture supernatant were injected into the distal stump of the tibial nerve, respectivel. The generalcondition of rats after operation was observed. At 4 and 12 weeks postoperatively, the wet weight of right musculus tricepssurae was measured, the HE staining, the Mallory trichrome staining and the postsynaptic membrane staining were adopted for the histological observation. Meanwhile, the section area of gastrocnemius fiber and the area of postsynaptic membrane were detected by image analysis software and statistical analysis. Results The wounds in both groups of animals healed by first intension, no ulcer occurred in the right hind l imbs. At 4 and 12 weeks postoperatively, the wet weight of right musculus triceps surae was (0.849 ± 0.064) g and (0.596 ± 0.047) g in the experimental group, respectively, and was (0.651 ± 0.040) g and (0.298 ± 0.016) g in the control group, respectively, showing a significant difference (P lt; 0.05). The fiber section area of the gastrocnemius was 72.55% ± 8.12% and 58.96% ± 6.07% in the experimental group, respectively, and was 50.23% ± 4.76% and 33.63% ± 4.41% in the control group, respectively. There were significant differences between them (P lt; 0.05). Mallory trichrome staining of muscle notified that there was more collagen fiber hyperplasia of denervated gastrocnemius in the control group than that in the experimental group at 4 and 12 weeks postoperatively. After 12 weeks of operation, the area of postsynaptic membrane in the experimental group was (137.29 ± 29.14) μm2, which doubled that in the control group as (61.03 ± 11.38) μm2 and was closer to that in normal postsynaptic membrane as (198.63 ± 23.11) μm2, showing significant differences (P lt; 0.05). Conclusion The transplantation in vivo of allogenic embryonic spinal cord NSCs is capable of delaying denervated muscle atrophy and maintaining the normal appearance of postsynaptic membrane, providing a new approach to prevent and treat the denervated muscle atrophy cl inically.