OBJECTIVE: To observe the effects of ultrasound-guided foraminal electroacupuncture on neuronal apoptosis and motor function in rats with spinal cord injury (SCI), and to explore the potential underlying mechanisms. METHODS: Thirty-six SPF-grade Sprague-Dawley rats were randomly assigned to a sham operation group, a model group, and an ultrasound-guilded electroacupuncture group (electroacupuncture group), with 12 rats in each group. In the sham operation group, the spinal cord was exposed and then the incision was sutured without contusion. In the other two groups, SCI models were established using a modified Allen's impact method. On days 1, 3, 7, and 14 after modeling, the electroacupuncture group received electroacupuncture intervention at the T₉/T₁₀ and T₁₀/T₁₁ intervertebral foramen under ultrasound guidance, avoiding spinal cord injury. Stimulation parameters were dense-disperse wave at 2 Hz/100 Hz and 1-2 mA for each session. Following interventions on days 1, 3, 7, and 14, the Basso-Beattie-Bresnahan (BBB) score was assessed; the inclined plane test was used to assess hindlimb grip strength in rats. After the intervention, HE staining was used to observe spinal cord morphology; TUNEL staining was used to detect neuronal apoptosis; ELISA was used to measure the serum levels of interleukin (IL)-6, IL-1β, and tumor necrosis factor-alpha (TNF-α); Western blot was used to analyze the protein expression of Wnt-4, β-catenin, c-Myc, Bax, Bcl-2, and NeuN in spinal tissue; quantitative real-time PCR was used to detect the mRNA expression of Wnt-4, β-catenin, c-Myc, Bax, Bcl-2, and NeuN. RESULTS: Compared with the sham operation group, the model group showed significantly reduced BBB scores (P<0.05), and reduced inclined plane angles (P<0.05) at all time points. Compared with the model group, the electroacupuncture group exhibited increased BBB scores on days 3, 7, and 14 (P<0.05), and higher inclined plane angles on days 1, 3, 7, and 14 (P<0.05). Compared with the sham operation group, the model group showed disorganized spinal cord structure with increased inflammatory cells and necrotic neurons, higher number of apoptotic neurons in spinal tissue (P<0.05), elevated serum IL-6, IL-1β, and TNF-α levels (P<0.05), increased protein and mRNA expression of Wnt-4, β-catenin, c-Myc, and Bax (P<0.05), and decreased protein and mRNA expression of Bcl-2 and NeuN in spinal tissue (P<0.05). Compared with the model group, the electroacupuncture group had fewer inflammatory cells and apoptotic neurons in spinal tissue (P<0.05), reduced serum IL-6, IL-1β, and TNF-α levels (P<0.05), increased protein and mRNA expression of Wnt-4, β-catenin, Bcl-2, and NeuN (P<0.05), and decreased protein and mRNA expression of c-Myc and Bax in spinal tissue (P<0.05). CONCLUSION Ultrasound-guided foraminal electroacupuncture could improve motor function in rats with SCI, potentially by regulating the expression of molecules related to the Wnt-4/β-catenin signaling pathway to inhibit neuronal apoptosis and inflammatory responses.
Animals ; Electroacupuncture/methods* ; Spinal Cord Injuries/physiopathology* ; Rats, Sprague-Dawley ; Rats ; Wnt Signaling Pathway ; Male ; Humans ; Female ; beta Catenin/metabolism* ; Apoptosis ; Ultrasonography ; Tumor Necrosis Factor-alpha/genetics* ; Spinal Cord/metabolism*

OBJECTIVE: To observe the effects of moxibustion at "Shenque" (CV8) on urodynamics and the expression of brain-derived neurotrophic factor (BDNF) and immediate early gene (c-fos) in pontine micturition center (PMC), periaqueductal gray (PAG), medial prefrontal cortex (mPFC) of neurogenic bladder (NB) rats after spinal cord injury. METHODS: Twenty-four SPF female SD rats were randomly divided into a sham-operation group (6 rats) and a modeling group (18 rats). In the modeling group, T₉ complete spinal cord transection method was used to establish a neurogenic detrusor overactivity model, and the 12 rats with successful modeling were randomized into a model group and a moxibustion group, with 6 rats in each group. The rats in the moxibustion group were treated with ginger/salt-insulated moxibustion at "Shenque" (CV8), and 4 consecutive moxa cones were delivered in one intervention. Moxibustion was operated once daily and for 14 days. After intervention completion, the urodynamic indexes of rats in each group were detected. Fluorescence quantitative PCR was used to detect the mRNA expression of BDNF and c-fos in PMC, PAG and mPFC in rats. Western blot was used to detect the protein expression of BDNF and c-fos in PMC, PAG and mPFC. RESULTS: The rats in the sham-operation group did not show phasic detrusor contraction during bladder filling. Compared with the model group, the frequency and amplitude of the phasic detrusor contraction were reduced 5 min before urine leakage in the rats of the moxibustion group (P<0.05), and the duration of the first phasic detrusor contraction during bladder filling was prolonged (P<0.05). Compared with the sham-operation group, the mRNA and protein expression of BDNF and c-fos in PMC, PAG and mPFC increased in the model group (P<0.05). Compared with the model group, the mRNA and protein expression of BDNF and c-fos in PMC, PAG and mPFC decreased in the moxibustion group (P<0.05). CONCLUSION Moxibustion at "Shenque" (CV8) can improve the phasic contraction during bladder filling in NB rats after spinal cord injury, possibly by down-regulating the mRNA and protein expression of BDNF and c-fos in PMC, PAG, and mPFC.
Animals ; Moxibustion ; Female ; Rats ; Brain-Derived Neurotrophic Factor/metabolism* ; Rats, Sprague-Dawley ; Acupuncture Points ; Spinal Cord Injuries/metabolism* ; Urinary Bladder, Neurogenic/etiology* ; Proto-Oncogene Proteins c-fos/metabolism* ; Humans ; Urinary Bladder/physiopathology* ; Brain/metabolism* ; Urination

Clinical trials have demonstrated that kilohertz-frequency transcutaneous spinal cord stimulation (TSCS) can be used to facilitate the recovery of sensory-motor function for patients with spinal cord injury, whereas the neural mechanism of TSCS is still undetermined so that the choice of stimulation parameters is largely dependent on the clinical experience. In this paper, a finite element model of transcutaneous spinal cord stimulation was used to calculate the electric field distribution of human spinal cord segments T ₁₂ to L ₂, whereas the activation thresholds of spinal fibers were determined by using a double-cable neuron model. Then the variation of activation thresholds was obtained by varying the carrier waveform, the interphase delay, the modulating frequency, and the modulating pulse width. Compared with the sinusoidal carrier, the usage of square carrier could significantly reduce the activation threshold of dorsal root (DR) fibers. Moreover, the variation of activation thresholds was no more than 1 V due to the varied modulating frequency and decreases with the increased modulating pulse width. For a square carrier at 10 kHz modulated by rectangular pulse with the frequency of 50 Hz and the pulse width of 1 ms, the lowest activation thresholds of DR fibers and dorsal column fibers were 27.6 V and 55.8 V, respectively. An interphase delay of 5 μs was able to reduce the activation thresholds of the DR fibers to 20.1 V. The simulation results can lay a theoretical foundation on the selection of TSCS parameters in clinical trials.
Humans ; Spinal Cord Stimulation/methods* ; Nerve Fibers/physiology* ; Finite Element Analysis ; Spinal Cord/physiology* ; Computer Simulation ; Spinal Cord Injuries/physiopathology* ; Lumbosacral Region ; Lumbar Vertebrae ; Transcutaneous Electric Nerve Stimulation/methods* ; Models, Neurological

OBJECTIVE: To investigate the effect of mild hypothermia on neurological function in rats with spinal cord injury (SCI) based on the adenosine monophosphate activated protein kinase (AMPK)/Nod-like receptor protein 3 (NLRP3) pathway. METHODS: Fifty 7-8 weeks old SPF male Sprague Dawley rats were used to establish rat model of SCI by Allen's method. Among them, 48 successfully modeled rats were randomly divided into SCI group, mild hypothermia group (SCI+mild hypothermia treatment), and Compound C group (SCI+mild hypothermia+intraperitoneal injection of 20 mg/kg AMPK/NLRP3 pathway inhibitor Compound C), with 16 rats in each group. Another 16 normal rats with laminectomy were selected as sham-operation group. Basso-Beattie-Bresnahan (BBB) score was used to evaluate the motor ability of rats at 1, 3, 7, 14 days after treatment. After 14 days, the rats were sacrificed, and the spinal cord histopathological morphology was observed by HE staining, the neuronal apoptosis in spinal cord tissue was detected by TUNEL assay, and the serum levels of interleukin 2 (IL-2), IL-6, transforming growth factor β ₁ (TGF-β ₁), malondialdehyde (MDA), and superoxide dismutase (SOD) were detected by ELISA. The expressions of AMPK/NLRP3 pathway proteins in spinal cord tissue, including B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X protein (Bax), and cleaved-Caspase-9 were detected by Western blot. RESULTS: At 1 day after treatment, the rats in SCI group, mild hypothermia group, and Compound C group did not recover their motor ability. With the prolongation of time, the motor function of rats in each group gradually recovered. Among them, the BBB score of SCI group was significantly lower than that of sham-operation group and mild hypothermia group ( P<0.05), and the BBB score of Compound C group was significantly lower than that of mild hypothermia group ( P<0.05). Compared with the sham-operation group, the SCI group displayed obvious pathological changes in the spinal cord tissue, with disordered tissue architecture, inflammatory infiltration, and blurred interstitial boundaries. The neuronal apoptosis rate, Bax/Bcl-2 ratio, cleaved Caspase-9 expression, NLRP3 protein expression, serum IL-2, IL-6, and MDA levels were elevated, whereas serum TGF-β ₁, SOD levels, and spinal cord phosphorylation AMPK/AMPK protein expression significantly decreased ( P<0.05). Compared with the SCI group, the above phenomena significantly improved in the mild hypothermia group ( P<0.05), while the Compound C group showed the opposite trend of change compared to the mild hypothermia group ( P<0.05). CONCLUSION Mild hypothermia can attenuate neurological dysfunction after SCI in rats, potentially by activating the AMPK/NLRP3 pathway.
Animals ; Spinal Cord Injuries/physiopathology* ; Rats, Sprague-Dawley ; Male ; Rats ; NLR Family, Pyrin Domain-Containing 3 Protein/metabolism* ; AMP-Activated Protein Kinases/metabolism* ; Hypothermia, Induced ; Signal Transduction ; Spinal Cord/pathology* ; Apoptosis ; Interleukin-6/metabolism* ; Disease Models, Animal ; bcl-2-Associated X Protein/metabolism* ; Superoxide Dismutase/metabolism* ; Proto-Oncogene Proteins c-bcl-2/metabolism* ; Caspase 9/metabolism*

OBJECTIVES: Neuropathic pain (NP) is one of the most common forms of chronic pain, yet current treatment options are limited in effectiveness. Peripheral nerve injury activates spinal microglia, altering their inflammatory response and phagocytic functions, which contributes to the progression of NP. Most current research on NP focuses on microglial inflammation, with relatively little attention to their phagocytic function. Early growth response factor 2 (EGR2) has been shown to regulate microglial phagocytosis, but its specific role in NP remains unclear. This study aims to investigate how EGR2 modulates microglial phagocytosis and its involvement in NP, with the goal of identifying potential therapeutic targets. METHODS: Adult male Sprague-Dawley (SD) rats were used to establish a chronic constriction injury (CCI) model of the sciatic nerve. Pain behaviors were assessed on days 1, 3, 7, 10, and 14 post-surgery to confirm successful model induction. The temporal and spatial expression of EGR2 in the spinal cord was examined using real-time quantitative PCR (RT-qPCR), Western blotting, and immunofluorescence staining. Adeno-associated virus (AAV) was used to overexpress EGR2 in the spinal cord, and behavioral assessments were performed to evaluate the effects of EGR2 modulation of NP. CCI and lipopolysaccharide (LPS) models were established in animals and microglial cell lines, respectively, and changes in phagocytic activity were measured using RT-qPCR and fluorescent latex bead uptake assays. After confirming the involvement of microglial phagocytosis in NP, AAV was used to overexpress EGR2 in both in vivo and in vitro models, and phagocytic activity was further evaluated. Finally, eukaryotic transcriptome sequencing was conducted to screen differentially expressed mRNAs, followed by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses to identify potential downstream effectors of EGR2. RESULTS: The CCI model successfully induced NP. Following CCI, EGR2 expression in the spinal cord was upregulated in parallel with NP development. Overexpression of EGR2 via spinal AAV injection enhanced microglial phagocytic activity and increased pain hypersensitivity in rats. Both animal and cellular models showed that CCI or LPS stimulation enhanced microglial phagocytosis, which was further amplified by EGR2 overexpression. Transcriptomic analysis of spinal cord tissues from CCI rats overexpressing EGR2 revealed upregulation of numerous genes associated with microglial phagocytosis and pain regulation. Among them, Lag3 emerged as a potential downstream target of EGR2. CONCLUSIONS EGR2 contributes to the maintenance of NP by enhancing microglial phagocytosis in the spinal dorsal horn.
Animals ; Microglia/metabolism* ; Phagocytosis/physiology* ; Rats, Sprague-Dawley ; Neuralgia/physiopathology* ; Early Growth Response Protein 2/metabolism* ; Male ; Rats ; Spinal Cord/metabolism* ; Sciatic Nerve/injuries*

Demyelination and remyelination play key roles in spinal cord injury (SCI), affecting the recovery of motor and sensory functions. Research in rodent models is extensive, but the study of these processes in non-human primates is limited. Therefore, our goal was to thoroughly study the histological features of demyelination and remyelination after contusion injury of the cervical spinal cord in Macaca fascicularis. In a previous study, we created an SCI model in M. fascicularis by controlling the contusion displacement. We used Eriochrome Cyanine staining, immunohistochemical analysis, and toluidine blue staining to evaluate demyelination and remyelination. The results showed demyelination ipsilateral to the injury epicenter both rostrally and caudally, the former mainly impacting sensory pathways, while the latter primarily affected motor pathways. Toluidine blue staining showed myelin loss and axonal distension at the injury site. Schwann cell-derived myelin sheaths were only found at the center, while thinner myelin sheaths from oligodendrocytes were seen at the center and surrounding areas. Our study showed that long-lasting demyelination occurs in the spinal cord of M. fascicularis after SCI, with oligodendrocytes and Schwann cells playing a significant role in myelin sheath formation at the injury site.
Animals ; Spinal Cord Injuries/physiopathology* ; Demyelinating Diseases/etiology* ; Remyelination/physiology* ; Macaca fascicularis ; Disease Models, Animal ; Myelin Sheath/pathology* ; Oligodendroglia/pathology* ; Schwann Cells/pathology* ; Female ; Spinal Cord/pathology* ; Axons/pathology*

OBJECTIVE: To observe the clinical effect and safety of fire needle therapy combined with bladder function training on neurogenic bladder (NB) caused by spinal cord injury. METHODS: A total of 60 patients with NB caused by spinal cord injury were randomly divided into an observation group and a control group , with 30 cases in each group. On the basis of conventional treatment with western medicine, the bladder function training was adopted in the control group, once a day and for 4 weeks. In the observation group, on the basis of the interventions as the control group, fire needling was operated at bilateral Sanyinjiao (SP 6) and Guanyuan (CV 4) and Zhongji (CV 3), once every two days and for 4 weeks (14 interventions in total). Separately, at the baseline and in 2 and 4 weeks of interventions, the urination conditions (average daily urination frequency, average daily leakage frequency, average daily single urination volume) were recorded in the two groups; the urodynamic parameters (maximum flow rate [Qmax], maximum detrusor pressure at maximum flow rate [PdetQmax], residual urine volume [RUA], maximum cystometric capacity [MCC], and bladder pressure) were detected; the neurogenic bladder symptom score (NBSS), urinary symptom distress score (USDS) were observed. Before and after treatment, the score of World Health Organization quality of life assessment scale-brief (WHOQOL-BREF) was observed in the two groups. The therapeutic effect, the incidence of urinary infection, and the safety were evaluated. RESULTS: In 2 and 4 weeks of interventions, the average daily urination frequency, the average daily leakage frequency, RUA, and the scores of NBSS and USDS decreased in the two groups when compared with the baseline (P<0.05). In 4 weeks of interventions, the above-mention outcomes were lower than those in 2 weeks of interventions (P<0.05); and the results in the observation group were lower in 2 and 4 weeks of interventions when compared with the control group (P<0.05). In 2 and 4 weeks of interventions, the average daily single urination volume, Qmax, PdetQmax, MCC, and bladder pressure increased in the two groups compared with the baseline (P<0.05). In 4 weeks of interventions, the above-mention outcomes were elevated in comparison with those in 2 weeks of interventions (P<0.05); and except for bladder pressure, the results in the observation group in 2 and 4 weeks of interventions were higher when compared with the control group (P<0.05). In 4 weeks of interventions, the scores of each dimension and the total scores of WHOQOL-BREF increased in comparison with the baseline in the two groups (P<0.05), and the scores of the observation group were higher than those of the control group (P<0.05). The incidence of urinary infection was 0% (0/30) in the observation group and 10.0% (3/30) in the control group, without significant difference (P>0.05). The total effective rate of the observation group was 93.3% (28/30), which was higher than that (73.3%, 22/30) of the control group (P<0.05). No serious adverse reactions occurred in the patients of the observation group. CONCLUSION Fire needle therapy combined with bladder function training can effectively relieve the clinical symptoms, ameliorate urination, restore bladder function and improve the quality of life in the patients with NB caused by spinal cord injury. This therapeutic regimen presents a high safety in practice.
Humans ; Spinal Cord Injuries/therapy* ; Female ; Male ; Acupuncture Therapy ; Middle Aged ; Adult ; Urinary Bladder, Neurogenic/etiology* ; Urinary Bladder/physiopathology* ; Urination ; Young Adult ; Treatment Outcome ; Aged ; Adolescent ; Combined Modality Therapy

The inhibitory environment that surrounds the lesion site and the lack of intrinsic regenerative capacity of the adult mammalian central nervous system (CNS) impede the regrowth of injured axons and thereby the reestablishment of neural circuits required for functional recovery after spinal cord injuries (SCI). To circumvent these barriers, biomaterial scaffolds are applied to bridge the lesion gaps for the regrowing axons to follow, and, often by combining stem cell transplantation, to enable the local environment in the growth-supportive direction. Manipulations, such as the modulation of PTEN/mTOR pathways, can also enhance intrinsic CNS axon regrowth after injury. Given the complex pathophysiology of SCI, combining biomaterial scaffolds and genetic manipulation may provide synergistic effects and promote maximal axonal regrowth. Future directions will primarily focus on the translatability of these approaches and promote therapeutic avenues toward the functional rehabilitation of patients with SCIs.
Animals ; Axons ; physiology ; Biocompatible Materials ; Genetic Enhancement ; methods ; Humans ; Nerve Regeneration ; PTEN Phosphohydrolase ; metabolism ; Recovery of Function ; Spinal Cord Injuries ; physiopathology ; Tissue Engineering ; methods ; Tissue Scaffolds

To investigate the role of p38MAPK signal pathway in spinal cord and dorsal root ganglion (DRG) in rats with phantom limb pain and the effects of specific inhibitors.
 Methods: Healthy adult male SD rats (n=48) were cut off one side of the sciatic under anesthesia to establish a model of phantom limb pain. In addition, the healthy rats were taken as a sham group (group S, n=24). The animals were scored by observing the action of chewing (0=no chewing, 13=the worst chewing) after the operation and were sacrificed on the following day after the operation. The successful model of phantom limb pain were randomly divided into 2 groups: a phantom limb pain group (group P, n=24) and a phantom limb pain plus inhibitor group (group P+I, n=24). SB203580 was given to the rat at 0.8 mg/kg on every Monday until the rats were sacrificed, the rest of the rats received an equal amount of saline. Eight rats from each group were randomly taken for the determination of levels of P-p38MAPK in spinal cord and DRG before administration and on the 4th, 6th, 8th weekend following the administration, respectively.
 Results: In the sham group, no animal developed chewing. Meanwhile, rats in successful model of phantom limb pain group began chewing from the 2nd day after operation with scores at eight to eleven. The chewing scores in the P+I group were reduced after the treatment. Compared with group S, P-p38MAPK levels were elevated in groups of P and P+I (P<0.05 or P<0.01). Compared with group P, P-p38MAPK level was decreased in the group P+I (P<0.05 or P<0.01).
 Conclusion: P38MAPK signal pathway involves in the development of phantom limb pain.
Animals ; Disease Models, Animal ; Enzyme Inhibitors ; pharmacology ; Ganglia, Spinal ; enzymology ; Imidazoles ; pharmacology ; Male ; Mastication ; physiology ; Phantom Limb ; enzymology ; etiology ; physiopathology ; Pyridines ; pharmacology ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Sciatic Nerve ; injuries ; Self Mutilation ; enzymology ; physiopathology ; Signal Transduction ; Spinal Cord ; enzymology ; p38 Mitogen-Activated Protein Kinases ; antagonists & inhibitors ; metabolism

OBJECTIVETo study the effects of sacral nerve root electrostimulation (SNS) on the colon function and its mechanisms in rats with spinal cord injury (SCI).

METHODSOne hundred and four Wistar rats were divided into three groups: A, B and C. A group ( n = 24) was divided into three subgroups (n = 8) for studying the bioelectricity: Normal group (NG), SCI group (SCI) and SCI group with SNS(SNS); B group( n = 24) was divided into three subgroups( n = 8) for studying the colon motility: NG, SCI and SNS. C group( n = 56) were divided into three groups for studying the change of morphology and neurotransmitters(SP and VIP): NG (n = 8), SCI (n = 24), and SNS (n = 24) . In SCI and SNS, included of three subgroups: 24, 48, 72 h after spinal cord injury (n = 8).

RESULTSIn SCI group, the activity of bioelectricity in proximal and distal colon was reduced; the colon motility was lessened, and colon mucosa appeared different degree of damage; cell-cell connections between intestinal epithelial cells were destroyed. The expressions of substance P(SP) and vasoactive intestinal peptide (VIP) in colon were decreased obviously. SNS was found to activate the bioelectricity, promote the colon motility, improve the intestinal mucosal, and increase the expressions of SP and VIP. Conclusion: SNS can activate the peristalsis, rehabilitate the motility of denervated colon, protection of the intestinal mechanical barrier between intestinal epithelial cells and tight junction, rebuild the colon function through activating the bioelectricity and increase the expressions of SP and VIP.

Animals ; Colon ; physiopathology ; Electric Stimulation Therapy ; Epithelial Cells ; drug effects ; Intestinal Mucosa ; drug effects ; Lumbosacral Region ; innervation ; Neurotransmitter Agents ; metabolism ; Rats ; Rats, Wistar ; Spinal Cord Injuries ; therapy ; Substance P ; metabolism ; Vasoactive Intestinal Peptide ; metabolism