The effect of magnetic stimulation (MS) on sciatic nerve injury was observed. After sciatic nerve was crushed in 40 Sprague Dawley (SD) rats, one randomly selected group (group D) was subjected, from the 4th day post-operatively to 3 min of continuous 70% of maximum output of MS daily for 8 weeks. The other group (group E) served as a control group. The nerve regeneration and motor function recovery were evaluated by walking track analysis (sciatic function index, SFI; toe spreading reflex, TSR), electrophysiological, histological and acetylcholineesterase histochemistry. The SFI in the group D was greater than in the group E with the difference being statistically significant (P < 0.01). TSR reached its peak on the 4th day in the group D and on the 10th day in the group E respectively. The amplitude and velocity of MCAP and NCAP in the group D was greater than in the group E with the difference being statistically significant (P < 0.01), while the latency and duration of MCAP and NCAP in the group D were less than in the group E with the difference being also statistically significant (P < 0.01). Histological examination showed the mean axon count above the lesion for thick myelinated fibers (> 6.5 microns) in the group D was greater than in the control group with the difference being statistically significant (P < 0.01), while the mean axon count below the lesion for thick myelinated fibers was less than that in the group E with the difference being statistically significant (P < 0.01). The mean axon count above the lesion for thin myelinated fibers (2-6.5 microns) in the group D was greater than that in the group E with the difference being statistically significant (P < 0.05), while the mean axon count below the lesion for thin myelinated in the group D was greater than that in the group E with the difference being statistically significant (P < 0.01). Acetylcholine esterase examination showed that the MS could significantly increase the number of the motor neurons. There was no significant difference in the number of the motor neurons between the treatment side and the normal side (P > 0.05). It can be concluded that MS can enhance functional recovery and has a considerable effect in the treatment of the peripheral nerve injury.
Acetylcholinesterase/metabolism ; Electromagnetics ; Motor Neurons/physiology ; *Nerve Regeneration ; Random Allocation ; Rats, Sprague-Dawley ; Sciatic Nerve/*injuries ; Sciatic Nerve/*physiopathology ; Sciatic Neuropathy/rehabilitation

Enhancing remyelination after injury is of utmost importance for optimizing the recovery of nerve function. While the formation of myelin by Schwann cells (SCs) is critical for the function of the peripheral nervous system, the temporal dynamics and regulatory mechanisms that control the progress of the SC lineage through myelination require further elucidation. Here, using in vitro co-culture models, gene expression profiling of laser capture-microdissected SCs at various stages of myelination, and multilevel bioinformatic analysis, we demonstrated that SCs exhibit three distinct transcriptional characteristics during myelination: the immature, promyelinating, and myelinating states. We showed that suppressor interacting 3a (Sin3A) and 16 other transcription factors and chromatin regulators play important roles in the progress of myelination. Sin3A knockdown in the sciatic nerve or specifically in SCs reduced or delayed the myelination of regenerating axons in a rat crushed sciatic nerve model, while overexpression of Sin3A greatly promoted the remyelination of axons. Further, in vitro experiments revealed that Sin3A silencing inhibited SC migration and differentiation at the promyelination stage and promoted SC proliferation at the immature stage. In addition, SC differentiation and maturation may be regulated by the Sin3A/histone deacetylase2 (HDAC2) complex functionally cooperating with Sox10, as demonstrated by rescue assays. Together, these results complement the recent genome and proteome analyses of SCs during peripheral nerve myelin formation. The results also reveal a key role of Sin3A-dependent chromatin organization in promoting myelinogenic programs and SC differentiation to control peripheral myelination and repair. These findings may inform new treatments for enhancing remyelination and nerve regeneration.
Animals ; Axons ; Chromatin/metabolism* ; Gene Expression Profiling ; Myelin Sheath/metabolism* ; Nerve Regeneration/physiology* ; Rats ; Schwann Cells/metabolism* ; Sciatic Nerve/injuries*

OBJECTIVE: It has been reported that local vibration therapy can benefit recovery after peripheral nerve injury, but the optimized parameters and effective mechanism were unclear. In the present study, we investigated the effect of local vibration therapy of different amplitudes on the recovery of nerve function in rats with sciatic nerve injury (SNI). METHODS: Adult male Sprague-Dawley rats were subjected to SNI and then randomly divided into 5 groups: sham group, SNI group, SNI + A-1 mm group, SNI + A-2 mm group, and SNI + A-4 mm group (A refers to the amplitude; n = 10 per group). Starting on the 7th day after model initiation, local vibration therapy was given for 21 consecutive days with a frequency of 10 Hz and an amplitude of 1, 2 or 4 mm for 5 min. The sciatic function index (SFI) was assessed before surgery and on the 7th, 14th, 21st and 28th days after surgery. Tissues were harvested on the 28th day after surgery for morphological, immunofluorescence and Western blot analysis. RESULTS: Compared with the SNI group, on the 28th day after surgery, the SFIs of the treatment groups were increased; the difference in the SNI + A-2 mm group was the most obvious (95% confidence interval [CI]: [5.86, 27.09], P < 0.001), and the cross-sectional areas of myocytes in all of the treatment groups were improved. The G-ratios in the SNI + A-1 mm group and SNI + A-2 mm group were reduced significantly (95% CI: [-0.12, -0.02], P = 0.007; 95% CI: [-0.15, -0.06], P < 0.001). In addition, the expressions of S100 and nerve growth factor proteins in the treatment groups were increased; the phosphorylation expressions of ERK1/2 protein in the SNI + A-2 mm group and SNI + A-4 mm group were upregulated (95% CI: [0.03, 0.96], P = 0.038; 95% CI: [0.01, 0.94], P = 0.047, respectively), and the phosphorylation expression of Akt in the SNI + A-1 mm group was upregulated (95% CI: [0.11, 2.07], P = 0.031). CONCLUSION Local vibration therapy, especially with medium amplitude, was able to promote the recovery of nerve function in rats with SNI; this result was linked to the proliferation of Schwann cells and the activation of the ERK1/2 and Akt signaling pathways.
Animals ; Male ; Peripheral Nerve Injuries/therapy* ; Proto-Oncogene Proteins c-akt/pharmacology* ; Rats ; Rats, Sprague-Dawley ; Sciatic Nerve/metabolism* ; Sciatic Neuropathy/metabolism* ; Vibration/therapeutic use*

The effect of magnetic stimulation (MS) on sciatic nerve injury was observed. After sciatic nerve was crushed in 40 Sprague Dawley (SD) rats, one randomly selected group (group D) was subjected, from the 4th day post-operatively to 3 min of continuous 70% of maximum output of MS daily for 8 weeks. The other group (group E) served as a control group. The nerve regeneration and motor function recovery were evaluated by walking track analysis (sciatic function index, SFI; toe spreading reflex, TSR), electrophysiological, histological and acetylcholineesterase histochemistry. The SFI in the group D was greater than in the group E with the difference being statistically significant (P < 0.01). TSR reached its peak on the 4th day in the group D and on the 10th day in the group E respectively. The amplitude and velocity of MCAP and NCAP in the group D was greater than in the group E with the difference being statistically significant (P < 0.01), while the latency and duration of MCAP and NCAP in the group D were less than in the group E with the difference being also statistically significant (P < 0.01). Histological examination showed the mean axon count above the lesion for thick myelinated fibers (> 6.5 microns) in the group D was greater than in the control group with the difference being statistically significant (P < 0.01), while the mean axon count below the lesion for thick myelinated fibers was less than that in the group E with the difference being statistically significant (P < 0.01). The mean axon count above the lesion for thin myelinated fibers (2-6.5 microns) in the group D was greater than that in the group E with the difference being statistically significant (P < 0.05), while the mean axon count below the lesion for thin myelinated in the group D was greater than that in the group E with the difference being statistically significant (P < 0.01). Acetylcholine esterase examination showed that the MS could significantly increase the number of the motor neurons. There was no significant difference in the number of the motor neurons between the treatment side and the normal side (P > 0.05). It can be concluded that MS can enhance functional recovery and has a considerable effect in the treatment of the peripheral nerve injury.
Acetylcholinesterase ; metabolism ; Animals ; Electromagnetic Phenomena ; Motor Neurons ; physiology ; Nerve Regeneration ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Sciatic Nerve ; injuries ; physiopathology ; Sciatic Neuropathy ; rehabilitation

This study was designed to elucidate the existence of PSD95 in the rat sciatic nerve. Immunohistochemical stains of cryosection and teased fiber of sciatic nerves were performed with goat polyclonal antibody against PSD95. Western blot analysis was also accomplished with the same antibody. We got an interesting result that the rat sciatic nerve obviously showed PSD95 immunoreactivity especially in the nodal and paranodal regions, and we also identified a distinct band of PSD95 by western blot. These results suggest PSD95 exists in the sciatic nerve as well as it does in the central nervous system. We suppose PSD95 may have some important roles in ion channel clustering, junctional plasticity and signal transduction in the peripheral nerves as well.
Animals ; Blotting, Western ; Cerebellum/cytology/metabolism ; Immunohistochemistry ; Nerve Fibers/metabolism/ultrastructure ; Nerve Tissue Proteins/*metabolism ; Rats ; Rats, Sprague-Dawley ; Sciatic Nerve/*metabolism

OBJECTIVE: To determine the expression and significance of p75NTR in the neuron and glia of dorsal root ganglia (DRG) in different injury models. METHODS: The models of sciatic nerve injury, spinal cord injury, and combined injury (sciatic nerve injury one week prior to spinal cord injury) were established. The rats were randomly divided into a normal group,a sciatic nerve injury group,a spinal cord injury group, and a combined injury group. The sensory neurons in the DRG were labeled by fast blue (FB) injected in the dorsal column of spinal cord 0.5mm rostral to the transection site. The expression of p75NTR in the neurons and glia of the DRG was examined with immunofluorescence histochemistry after different kinds of injury and its expression in the FB positive neurons was further observed with immunofluorescence histochemistry combined with FB retrograde labeling. RESULTS: The expression of p75NTR was increased in the glia, but was downregulated in sensory neurons in the sciatic nerve injury group compared with the normal group. p75NTR immunoreactive products were downregulated in the glia in the spinal cord injury group compared with the sciatic nerve injury group or the combined injury group. In the combined lesion animals, the expression of p75NTR was similar to that of the sciatic nerve injury group. Its expression in the sensory neurons of DRG was downregulated,but was upregulated in the glia. The majority of sensory neurons labeled by FB in the combined injury group were p75NTR-negative, but surrounded by p75NTR-positive glia. CONCLUSION p75NTR immunoreactive products in the glia and neurons of DRG have significant discrepancy after injury. The glial p75NTR in the DRG may play a role in the enhanced regeneration of acsending tract in the injured spinal cord after combined injury.
Animals ; Ganglia, Spinal ; metabolism ; pathology ; Male ; Neuroglia ; metabolism ; Neurons ; metabolism ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Receptors, Nerve Growth Factor ; metabolism ; Sciatic Nerve ; injuries ; metabolism ; Spinal Injuries ; metabolism

OBJECTIVETo investigate the therapeutic effect of nerve growth factor (NGF) on changes of myelin basic protein (MBP) and functional repair of sensory and motor nerve following sciatic nerve injury.

METHODSThe sciatic nerves of rats were injured by sectioning with shaver,and divided into 3 groups: NGF group (Group A), group of normal saline solution (Group B), untreated group (Group C). The time point of observation was at the 4th week after operation. Sensory evoked potential (SEP) and motor evoked potential (MEP) were detected by Model WD-4000 nerve potential working diagnosis system. Immunohistochemical analysis was used for identification of MBP.

RESULTSThe latency of SEP in the Group A at the 4th week after operation was shorter than that in the Group B (P<0.05). The MEP was elicited in 76% of the Group A and was higher than that in the Group B. Results of immunohistochemistry showed that there were less MBP-positive cells in the Group A than in the Group B in one and four weeks respectively.

CONCLUSIONSNGF can improve the conductive function of injured peripheral nerve and facilitate regeneration of nerve.

Animals ; Evoked Potentials ; Female ; Immunohistochemistry ; Myelin Basic Protein ; metabolism ; Nerve Growth Factor ; pharmacology ; Peripheral Nerve Injuries ; Peripheral Nerves ; metabolism ; Rats ; Rats, Wistar ; Sciatic Nerve ; injuries ; metabolism

OBJECTIVE: To observe the effects of electroacupuncture (EA) at "Jiaji" (EX-B 2) points combined with nerve mobilization on protein and mRNA expression of RhoA in rabbits with sciatic nerve injury, and to provide theoretical basis for the treatment of peripheral nerve injury by EA at "Jiaji" (EX-B 2) points combined with nerve mobilization. METHODS: A total of 180 New Zealand rabbits were randomly divided into a normal control group, a model control group, a nerve mobilization group, an EA group, an EA plus nerve mobilization group, 36 rabbits in each group. Each group was further divided into a 1-week subgroup, 2-week subgroup and 4-week subgroup, 12 rabbits in each subgroup. The sciatic nerve injury model was made by clamping method. The rabbits in the normal control group did not receive any intervention. The rabbits in the model control group was normally fed after operation. The rabbits in the nerve mobilization group were treated with nerve mobilization; the manipulation lasted for 1 s and relaxed for 5 s, 10 times per day, 6 days per week. The rabbits in the EA group were treated with EA at "Jiaji" (EX-B 2) points (L-L), once a day, 30 min each time, 6 times per week. The rabbits in the EA plus nerve mobilization group were treated with EA at "Jiaji" (EX-B 2) points, followed by nerve mobilization. The function of sciatic nerve on the injured side was evaluated by toe tension reflex and modified Tarlov score; the tissues of corresponding segments of spinal cord L-L and sciatic nerve were taken; the expression of RhoA gene was detected by real-time PCR and the expression of RhoA protein was detected by Western Blot. RESULTS: ① Toe tension reflex and modified Tarlov score: at 1, 2 and 4 weeks, the scores in the model control group were lower than those in the normal control group (all <0.01). The scores in the subgroup of nerve mobilization group, EA group and EA plus nerve mobilization group were higher than those in the model control group (all <0.01), and the scores in the subgroup of EA plus nerve mobilization group were higher than those in the nerve mobilization group and the EA group (all <0.01); the recovery was the best at 4 weeks. ② The mRNA and protein expression of RhoA: in segment of spinal cord, at 1, 2 and 4 weeks, the expression in the model control group was higher than that in the normal control group (all <0.01). The expression in the subgroup of nerve mobilization group, EA group and EA plus nerve mobilization group was lower than that in the model control group (all <0.01), and the expression in the subgroup of EA plus nerve mobilization group was lower than that in the nerve mobilization group and the EA group (all <0.01); at 1 week and 4 weeks, the expression in the nerve mobilization group was lower than that in the EA group (all <0.01); at 2 weeks, the expression in the nerve mobilization group was higher than that in the EA group (all <0.01). In the sciatic nerve, at 1, 2 and 4 weeks, the expression in the model control group was higher than that in the normal control group (all <0.01). The expression in the subgroup of nerve mobilization group, EA group and EA plus nerve mobilization group was lower than that in the model control group (all <0.01); at 2 weeks and 4 weeks, the expression in the EA plus nerve mobilization group was lower than that in the nerve mobilization group and EA group (all <0.01); at 1 week, the expression in the nerve mobilization group was lower than that in the EA group and EA plus nerve mobilization group (all <0.01), but the differences between the EA group and the EA plus nerve mobilization group were not significant (>0.05); at 2 weeks, the expression in the nerve mobilization group was higher than that in the EA group (all <0.01); at 4 weeks, the expression in the nerve mobilization group was lower than that in the EA group (all <0.01). CONCLUSION The nerve mobilization and EA at "Jiaji" (EX-B 2) points could both promote the repair of injured sciatic nerve, which may be related to the down-regulation of RhoA expression, and the combination of the two methods has better effects.
Acupuncture Points ; Animals ; Chlorophenols ; Electroacupuncture ; Peripheral Nerve Injuries ; RNA, Messenger ; metabolism ; Rabbits ; Sciatic Nerve ; injuries ; rhoA GTP-Binding Protein

OBJECTIVETo investigate the dynamic changes of alpha-tubulin, beta-tubulin and beta-actin in sciatic nerve of hen with organophosphorus ester-induced delayed neuropathy (OPIDN).

METHODSOPIDN was induced in 10-month-old Roman hens by daily subcutaneous administration of 30 mg/kg methamidophos for 15 days. Hens were sacrificed 2, 10, and 23 days respectively after manifesting neuropathy. The sciatic nerves were dissected, homogenized and used for the determination of the alpha-tubulin, beta-tubulin and beta-actin levels by western blotting.

RESULTSThe levels of alpha-tubulin in supernatant of sciatic nerves were decreased by 6%, 15% and 25% respectively on day 2, 10 and 23 respectively, while those in pellet remained almost unchanged. beta-tubulin were decreased by 27%, 6%, 19% in pellet and 1%, 21%, 22% in supernatant of sciatic nerves on 2, 10 and 23 days. Beta-actin level in pellet of sciatic nerve increased by 24%, 48% and 17% on day 2, 10 and 23, and little changes were observed in supernatant.

CONCLUSIONMethamidophos may induced changes of alpha-tubulin, beta-tubulin and beta-actin levels in sciatic nerve of hen, which may be one of the mechanism of the contribution to the occurrence and development of OPIDN.

Actins ; metabolism ; Animals ; Chickens ; Female ; Insecticides ; toxicity ; Organothiophosphorus Compounds ; toxicity ; Sciatic Nerve ; drug effects ; metabolism ; Tubulin ; metabolism

OBJECTIVETo investigate whether there is neogenesis of myelin sheath and neuron after transplantation of Schwann cells into cerebral hemorrhage lesion.

METHODSSchwann cells were expanded, labeled with BrdU in vitro and transplanted into rat cerebral hemorrhage with blood extracted from femoral artery and then injected into the basal nuclei. Double immunohistochemistry staining and electron microscopy were used to detect the expression of BrdU/MBP and BrdU/GAP-43 and remyelination.

RESULTSBrdU/MBP double positive cells could be seen at 1 week up to 16 weeks after transplantation of Schwann cells. Thin remyelination was observed under electron microscope. GAP-43 positive cells appeared after 12 weeks and were found more in Hippocamp.

CONCLUSIONSGrafted Schwann cells participate in remyelination and promoter nerve restore in rat cerebral hemorrhage.

Animals ; Cerebral Hemorrhage ; metabolism ; therapy ; GAP-43 Protein ; metabolism ; Rats ; Rats, Wistar ; Schwann Cells ; metabolism ; transplantation ; Sciatic Nerve ; cytology ; embryology