Bone marrow-derived mesenchymal stem cells (BMSCs) for repairing damaged heart tissue are a new kind of important treatment options because of their potential to differentiate into cardiomyocytes. We in this experiment investigated the effect of different electrical stimulation time on the expression of myocardial specificity gene and protein in rat bone marrow mesenchymal stem cells (rBMSCs) in vitro. The rBMSCs of second or third generation were randomly divided into three groups, i.e. electrical stimulation (ES) group, 5-Azacytidine (5-Aza) group and the control group. The rBMSCs in the ES groups with complete medium were exposed to 2 V, 2 Hz, 5 ms electrical stimulation for 0.5 h, 2 h, 4 h, and 6 h respectively every day for 10 days. Those in the 5-Aza group were induced by 5-Aza (10 μmol/L) for 24 h, and then cultured with complete medium for 10 days. Those in the control group were only cultured with complete medium, without any treatment, for 10 days. The rBMSCs' morphological feature in each group was observed with inverted phase microscope. The mRNA expression of myocyte-specific enhancer factor 2C (MEF-2C) and connexin 43 (Cx43) were examined with Real-Time quantitative PCR and the protein expression of MEF-2C, Cx43 were detected with Western Blot method. The results showed that the mRNA expression level of the MEF-2C, Cx43 and the protein expression level of MEF-2C, Cx43 were significantly higher in the ES group and 5-Aza group than those in the relative control group (P < 0.05). It suggests that electrical stimulation could play a part of role in the induction of the rBMSCs to differentiate into the cariomyocyte-like cells in vitro and the effectiveness of the electrical stimulation with 2 h/d had the best in our experiement. But the mechanism how electrical stimulation promotes the differentiation of rBMSC into cardiomyocyte is still unclear.
Objective To systematically review the effect of percutaneous acupoint electrical stimulation (TEAS) on heart rate variability (HRV). Methods The PubMed, Embase, Ovid MEDLINE, Cochrane Library, CNKI, WanFang Data, VIP, and CBM databases were electronically searched to collect randomized controlled trials (RCTs) on the effects of percutaneous acupoint electrical stimulation on heart rate variability from inception to February 28, 2023. Two reviewers independently screened the literature, extracted data, and assessed the risk of bias of the included studies. Meta-analysis was then performed using RevMan 5.4 software. Results A total of 14 RCTs involving 719 patients were included. The results of meta-analysis showed that SDNN (MD=12.95, 95%CI 9.18 to 16.72, P<0.01), RMSSD (MD=1.81, 95%CI 0.10 to 3.53, P=0.04), pNN50 (MD=1.75, 95%CI 1.02 to 2.48, P<0.01), HF (SMD=0.27, 95%CI 0.01 to 0.52, P=0.04), LF/HF (MD=−0.07, 95%CI −0.12 to −0.03, P<0.01), ln-LF (MD=0.63, 95%CI 0.25 to 1.01, P<0.01), ln-HF (MD=1.05, 95%CI 0.60 to 1.49, P<0.01), mean RR (MD=−11.86, 95%CI −21.77 to −1.96, P=0.02), and HR (SMD=−0.43, 95%CI −0.66 to −0.20, P<0.01) all showed improvement compared with the control group. However, there were no significant differences between the two groups in LF (SMD=0.15, 95%CI −0.10 to 0.40, P=0.23), LF norm (SMD=0.24, 95%CI −0.10 to 0.58, P=0.16) or HF norm (SMD=0.25, 95%CI −0.47 to 0.97, P=0.5). TEAS on PC6: SDNN, pNN50, HF, LF/HF, LF norm, HF norm, ln-LF, ln-HF, and HR all showed improvement compared with the control group. However, there were no significant differences between the two groups in RMSSD, LF, or RR interval. Conclusion This study supports the improvement of heart rate variability by transcutaneous acupoint electrical stimulation and PC6 acupoint selection. Due to the limited quantity and quality of the included studies, more high-quality studies are needed to verify the above conclusion.
In order to enhance the therapeutic effectiveness of peripheral nerve injury, intraoperative extrab electrical stimulation was used in peripheral nerve surgery. In 16 cases of incomplete peripheral rnerve injuries or poorly regeneratedn erves, continuous intraoperative electrophysiological monitoring was used for guidance of neurolysis. Meanwhile, extrastong electrical stimulation was applied. The latency and amplitude before and after electrical stimulation were recorded and the extent of improrement was compared. In all cases, the latency and amplitude were improved after neurolysis and electrical stimulation. Clinical follow-up also showed that the function of corresponding innorvated muscle was improved. Continuous intraoperative extrab electrical stimulation could be used as an practical measure to increase the effectiveness of peripheral nerve treatment.
Abstract This experiment was to study the feasibility from direct observation of muscle contraction of the lower extremity fromelectrical stimulation threshold of nerve fascicle in identifying the Iα intrafusal afferent fibers during selective posterior rhizotomy (SPR) and to investigate the clinical relationship between the muscle spasm and the electrical stimulation of nerve fascicles. The electrical stimulation threshold of all nerve fascicles in 36 cases during SPR were analysed statistically. The results showed that there was a significant difference between the electrical stimulation threshold of the severed nerve fascicles and intact nerve fascicles no matter the nerve root or each posterior nerve rootlet was examined. It was simple and reliable for surgeons to identify correctly the Iα intrafusal afferent fibers intraoperatively from direct observation of the electrical stimulation threshold of nerve fascicle.
Transcranial electrical stimulation (TES) is a non-invasive neuromodulation technique with great potential. Electrode optimization methods based on simulation models of individual TES field could provide personalized stimulation parameters according to individual variations in head tissue structure, significantly enhancing the stimulation accuracy of TES. However, the existing electrode optimization methods suffer from prolonged computation times (typically exceeding 1 d) and limitations such as disregarding the restricted number of output channels from the stimulator, further impeding their clinical applicability. Hence, this paper proposes an efficient and practical electrode optimization method. The proposed method simultaneously optimizes both the intensity and focality of TES within the target brain area while constraining the number of electrodes used, and it achieves faster computational speed. Compared to commonly used electrode optimization methods, the proposed method significantly reduces computation time by 85.9% while maintaining optimization effectiveness. Moreover, our method considered the number of available channels for the stimulator to distribute the current across multiple electrodes, further improving the tolerability of TES. The electrode optimization method proposed in this paper has the characteristics of high efficiency and easy operation, potentially providing valuable supporting data and references for the implementation of individualized TES.
Deep brain stimulation (DBS) has been successfully used to treat a variety of brain diseases in clinic. Recent investigations have suggested that high frequency stimulation (HFS) of electrical pulses used by DBS might change pathological rhythms in action potential firing of neurons, which may be one of the important mechanisms of DBS therapy. However, experimental data are required to confirm the hypothesis. In the present study, 1 min of 100 Hz HFS was applied to the Schaffer collaterals of hippocampal CA1 region in anaesthetized rats. The changes of the rhythmic firing of action potentials from pyramidal cells and interneurons were investigated in the downstream CA1 region. The results showed that obvious θ rhythms were present in the field potential of CA1 region of the anesthetized rats. The θ rhythms were especially pronounced in the stratum radiatum. In addition, there was a phase-locking relationship between neuronal spikes and the θ rhythms. However, HFS trains significantly decreased the phase-locking values between the spikes of pyramidal cells and the θ rhythms in stratum radiatum from 0.36 ± 0.12 to 0.06 ± 0.04 (P < 0.001, paired t-test, N = 8). The phase-locking values of interneuron spikes were also decreased significantly from 0.27 ± 0.08 to 0.09 ± 0.05 (P < 0.01, paired t-test, N = 8). Similar changes were obtained in the phase-locking values between neuronal spikes and the θ rhythms in the pyramidal layer. These results suggested that axonal HFS could eliminate the phase-locking relationship between action potentials of neurons and θ rhythms thereby changing the rhythmic firing of downstream neurons. HFS induced conduction block in the axons might be one of the underlying mechanisms. The finding is important for further understanding the mechanisms of DBS.
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 T12 to L2, 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.
ObjectiveTo observe the effect of Mongolian medicine fumigation combined with sciatic nerve and rectal probe electrical stimulation on muscle spasticity of spinal cord injury.MethodsBetween January 2012 and January 2018, a total of 65 patients with muscle spasticity after spinal cord injury were randomly divided into two group: the observation group (32 cases) and the control group (33 cases). The patients in the observation group were treated with Mongolian medicine (Wu Wei Gan Lu-Decoction) fumigation combined with sciatic nerve and rectal probe electrical stimulation, while the patients in the control group were treated with medicine, physical therapy, and exercise therapy. Both two groups were treated for 8 weeks. The patients were scored with Ashworth Score, American Spinal Injury Association (ASIA) score, and Barthel Index before and after treatment.ResultsThe pre-treatment ASIA scores (light touch sensation, pain sensation, and muscle strength) and Barthel Index of the two groups were not statistically significant (P>0.05). The post-treatment ASIA scores and Barthel Index of both groups performed significantly better than the pre-treatment levels (P<0.05). The post-treatment ASIA muscle strength item was 58.55±10.83 in the observation group and 50.69±11.32 in the control group (P<0.05). The post-treatment Barthel Index was 74.22±11.53 in the observation group and 68.46±9.92 in the control group (P<0.05). The effective rate in the observation group was significantly better than that in the control group (84.4% vs. 60.6%, P<0.05). Conclusion Mongolian medicine fumigation combined with sciatic nerve and rectal probe electric stimulation could improve the muscle spasticity of spinal cord injury and patients’ ability of daily life effectively.
Transcuataneous electrical nerve stimulation (TENS) analgesia as a non-drug method has received people's more and more attention recently. Considering problems of existing products, such as unstable performance and unsatisfied effectiveness, we developed a new analgesia therapy system for delivery based on bio-feedback TENS in our laboratory. We proposed a new idea for stimulation signal design, that is, we modulated a middle frequency signal by a traditional low frequency TENS wave in the new system. We designed different prescription waves for pain relief during a uterine contraction or massage between contractions. In the end, a bio-feedback TENS method was proposed, in which the waveforms of stimulation signals were selected and their parameters were modified automatically based on feedback from uterine pressure, etc. It was proved through quality tests and clinical trials that the system had good performance and satisfied analgesia effectiveness.