• Journal of Magnetics
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• v.15 no.4
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• pp.213-220
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• 2010

Since the hypothalamus immediately reacts to a nerve by processing all the information from the human body and the external stimulus being conducted, it performs a significant role in internal secretion; thus, a diverse and rapid stimulus pulse is required. By detecting Zero Detector accurately via the application of AVR on-Chip (ATMEL) using commercial electricity, chopping generates a stimulus pulse to the brain using an IGBT gate to designate a new magnetic stimulation following treatment and diagnosis. To simplify and generate a diverse range of stimuli for the brain, chopping can be used as a free magnetic stimulator. Then, commercial frequency (60Hz) is chopped precisely at the first level of the leakage transformer to deliver an appropriate stimulus pulse towards the hypothalamus when necessary. Discharge becomes stable, and the chopping frequency and duty-ratio provide variety after authorizing a high-pressure chopping voltage at the second level of the magnetic stimulator. These methods have several aims. The first is to apply a variable stimulus pulse via accurate switching frequency control by a voltaic pulse or a pulse repetition rate, according to the diagnostic purpose for a given hypothalamus. Consequently, the efficiency tends to increase. This experiment was conducted at a maximum of 210 W, a magnetic induced amplitude of 0.1~2.5 Tesla, a pulse duration of $200{\sim}350\;{\mu}s$, magnetic inducement of 5 Hz, stimulus frequency of 0.1~60 Hz, and a duration of stimulus train of 1~10 sec.

• The Korean Journal of Physiology and Pharmacology
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• v.24 no.6
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• pp.517-527
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• 2020

Layer 2/3 pyramidal neurons (L2/3 PyNs) of the cortex extend their basal dendrites near the soma and as apical dendritic tufts in layer 1, which mainly receive feedforward and feedback inputs, respectively. It is suggested that neuromodulators such as serotonin and acetylcholine may regulate the information flow between brain structures depending on the brain state. However, little is known about the dendritic compartment-specific induction of synaptic transmission in single PyNs. Here, we studied layer-specific serotonergic and cholinergic induction of long-term synaptic plasticity in L2/3 PyNs of the agranular insular cortex, a lateral component of the orbitofrontal cortex. Using FM1-43 dye unloading, we verified that local electrical stimulation to layers 1 (L1) and 3 (L3) activated axon terminals mostly located in L1 and perisomatic area (L2/3). Independent and AMPA receptor-mediated excitatory postsynaptic potential was evoked by local electrical stimulation of either L1 or L3. Application of serotonin (5-HT, 10 μM) induced activity-dependent longterm depression (LTD) in L2/3 but not in L1 inputs. LTD induced by 5-HT was blocked by the 5-HT₂ receptor antagonist ketanserin, an NMDA receptor antagonist and by intracellular Ca²⁺ chelation. The 5-HT₂ receptor agonist α-me-5-HT mimicked the LTD induced by 5-HT. However, the application of carbachol induced muscarinic receptor-dependent LTD in both inputs. The differential layer-specific induction of LTD by neuromodulators might play an important role in information processing mechanism of the prefrontal cortex.

• Korean Journal of Acupuncture
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• v.35 no.4
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• pp.187-202
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• 2018

Objectives : Non-invasive transcranial electrical stimulation is one of therapeutic interventions to change in neural excitability of the cortex. Transcranial electro-acupuncture (TEA) can modulate brain functions through changes in cortical excitability as a model of non-invasive transcranial electrical stimulation. Some composites of fermented Scutellaria baicalenis (FSB) can activate intercellular signaling pathways for activation of brain-derived neurotrophic factor that is critical for formation of neural plasticity in stroke patients. This study was aimed at evaluation of combinatory treatment of TEA and FSB on behavior recovery and cortical neural excitability in rodent focal stroke model. Methods : Focal ischemic stroke was induced by photothrombotic injury to the motor cortex of adult rats. Application of TEA with 20 Hz and $200{\mu}A$ in combination with daily oral treatment of FBS was given to stroke animals for 3 weeks. Motor recovery was evaluated by rotating bean test and ladder working test. Electrical activity of cortical pyramidal neurons of stroke model was evaluated by using multi-channel extracellular recording technique and thallium autometallography. Results : Compared with control stroke group who did not receive any treatment, Combination of TEA and FSB treatment resulted in more rapid recovery of forelimb movement following focal stroke. This combination treatment also elicited increase in spontaneous firing rate of putative pyramidal neurons. Furthermore expression of metabolic marker for neural excitability was upregulated in peri-infract area under thallium autometallography. Conclusions : These results suggest that combination treatment of TEA and FSB can be a possible remedy for motor recovery in focal stroke.

• The Korea Journal of Herbology
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• v.30 no.2
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• pp.43-48
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• 2015

Objectives : The aim of this study was to investigate the memory enhancing properties of extract of Hoelen Cum Radix (HCR) and its possible mechanism in mice of normal condition. Methods : We evaluated the effects of HCR on cognitive function and memory enhancement in normal mice. Male ICR mice were orally administrated with HCR 100 mg/kg for 7 days and equal volume of saline was administrated to the control group in the same condition. We conducted two behavioral tests which measure the spatial working memory (Y-maze test) and cognitive fear memory (passive avoidance test). We also investigated whether HCR affects the hippocampal neurogenesis in the brain. To assess the effects of HCR on neural progenitor cell differentiation and neurite outgrowth in the early stage of hippocampal neurogenesis, we performed doublecortin (DCX), a direct neurogenesis marker, immunohistochemical analysis in the dentate gyrus (DG) of the mouse hippocampus. Results : HCR significantly enhanced memory and cognitive function as determined by the Y-maze test (p<0.05) and passive avoidance test (p<0.001). Moreover, HCR increased DCX positive cells (p<0.01) and neurite length (p<0.01) compared to the control group. These results indicated that HCR stimulates differentiation of neural progenitor cells and promotes neurite outgrowth in hippocampal DG of the mice. Conclusion : We concluded that HCR shows memory enhancing effects through the stimulation of hippocampal neurogenesis as a consequence of accelerated neuronal differentiation and neurite outgrowth in the DG of the hippocampus after HCR treatment.

• Journal of Biomedical Engineering Research
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• v.45 no.2
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• pp.101-107
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• 2024

Steady-state visual evoked potential-based brain-computer interface (SSVEP-BCI) is one of the promising systems that can serve as an alternative input device due to its stable and fast performance. However, one of the major bottlenecks is that some individuals exhibit no or very low SSVEP responses to flickering stimulation, known as SSVEP illiteracy, resulting in low performance on SSVEP-BCIs. However, a lengthy duration is required to enhance multiple SSVEP responses using traditional single-frequency transcranial alternating current stimulation (tACS). This research proposes a novel approach using dual-frequency tACS (df-tACS) to potentially enhance SSVEP by targeting the two frequencies with the lowest signal-to-noise ratio (SNR) for each participant. Seven participants (five males, average age: 24.42) were exposed to flickering checkerboard stimuli at six frequencies to determine the weakest SNR frequencies. These frequencies were then simultaneously stimulated using df-tACS for 20 minutes, and the experiment was repeated to evaluate changes in SSVEP responses. The results showed that df-tACS effectively enhances the SNR at each targeted frequency, suggesting it can selectively improve target frequency responses. The study supports df-tACS as a more efficient solution for SSVEP illiteracy, proposing further exploration into multi-frequency tACS that could stimulate more than two frequencies, thereby expanding the potential of SSVEP-BCIs.

• Biomedical Science Letters
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• v.21 no.2
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• pp.92-102
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• 2015

This work aimed to study whether rice bran extract fermented with Lactobacillus plantarum (LW) promotes functional recovery and reduces cognitive impairment after ischemic brain injury. Ischemic brain injury was induced by middle cerebral artery occlusion (MCAO) in rats. Four groups were studied, namely the (1) sham, (2) vehicle, (3) donepezil, and (4) LW groups. Animals were injected with LW once a day for 7 days after middle cerebral artery occlusion. LW group showed significantly improved neurological function as compared to the vehicle group, as well as enhanced learning and memory in the Morris water maze. The LW group showed the greatest functional recovery. Moreover, the LW group showed an enhanced more survival cells anti-apoptotic effect in the cortex and neural cell densities in the hippocampal DG and CA1. In addition, this group showed enhanced expression of neurotrophic factors, antioxidant genes, and the acetylcholine receptor gene, as well as synaptophysin (SYP), Fox-3 (NeuN), doublecortin (DCX), and choline acetyltransferase (ChAT) proteins. Our findings indicate that LW treatment showed the largest effects in functional recovery and cognitive improvement after ischemic brain injury through stimulation of the acetylcholine receptor, antioxidant genes, neurotrophic factors, and expression of NeuN, SYP, DCX, and ChAT.

• Journal of Nutrition and Health
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• v.20 no.5
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• pp.318-329
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• 1987

Weanling female Sprague Dawley rate were fed 1.2mg pyridoxine' HCl/kg diet Cdepleted diet) and 2 22mg pyridoxine' HCI/kg dietCcontrol diet). The control and one depleted group were fed their diets throughout growth, gestation, and lactation. Other three depleted groups were fed the depleted diet throught growth and gestation, and then pyridoxine w was supplemented by feeding control diet at 5, 10, and 21 days postpartum. The brains were analyzed for proteolipid protein, cholesterol, and cerebrosi­d de. Percentage stimulation of erythrocyte alanine aminotransferase activity was also determined. Body and brain weight were significantly lower at all ages in depleted group than the control and depleted group showed inadequacy of B6 at all ages. PProteolipid protein and cholesterol were significa­n ntlylower in the depleted group at 10, 21, 35 and 5 50 days. The postnatal development of cerebroside in brain was delayed in depleted groups suppleme­I nted at 5, 10, and 21 days. When supplementation was initiateo at 5 days postparturn, contents of cho­lesterol proteolipid protein were reversed. But some differences in brain development of pups we­re evident when supplementation of dams was de­layed to 10 days or 21 days.

• International Journal of Oral Biology
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• v.34 no.1
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• pp.29-36
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• 2009

Cyclosporin A (CsA) has been used clinically as an immunosuppressive drug to prevent organ transplant rejection and in basic research as a mitochondrial permeability blocker. It has been reported that CsA has a protective role in severed neurons and a neurotrophic effect in neuronal cells. However, the molecular mechanisms underlying the stimulation of neuronal cell proliferation by CsA have not yet been elucidated. In our current study, we investigated CsA responsive proteins in PC12 cells using a systematic proteomic approach. The viability of these cells following CsA treatment increased in a dose- and time-dependent manner. Proteins in the CsA-treated PC12 cells were profiled by two-dimensional gel electrophoresis (2-DE) and identified by matrix-assisted laser desorption ionization time-of flight (MALDI-TOF) and electrospray ionization quadupole time-of-flight mass spectrometries (EIQ-TOFMS). This differential expression analysis showed significant changes for 10 proteins (6 up-regulated and 4 down-regulated) upon CsA treatment that were related to cell proliferation, metabolism and the stress response. These proteomics data further our understanding of the proliferation mechanisms of PC12 cells exposed to CsA and demonstrate that our methodology has potential to further elucidate the mechanisms and pathways involved.

• Journal of the Korea Convergence Society
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• v.12 no.2
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• pp.61-66
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• 2021

This study aimed to investigate the effect of changes in pain on the autonomic nervous system and brain waves after inducing delayed-onset muscle soreness(DOMS). Based on voluntary participation, 28 participants with induced-DOMS were randomly divided into control(non-treatment, n=14) and experiment groups(transcutaneous electrical nerve stimulation (TENS) and kinesio taping, n=14). Intervention was performed from first day to fifth days after the onset of DOMS. Measurements were performed using the Visual Analogue Scale(VAS), Heart Rate Variability(HRV), and brain wave before DOMS induction, 24 hours after, fifth day after, and eighth day after. According to the study results, when DOMS occurred, the activity of the sympathetic nervous system was increased or the activity of the parasympathetic nervous system was suppressed, and reduction of pain due to interventions showed the opposite activity. A decreased in alpha was seen during pain, but was not significant. These results will help develop and study pain management and treatment strategies.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.17 no.1
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• pp.38-46
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• 2024

In general, EEG signal analysis has been the subject of several studies due to its ability to provide an objective mode of recording brain stimulation, which is widely used in brain-computer interface research with applications in medical diagnosis and rehabilitation engineering. In this study, we developed EEG reception hardware to measure electroencephalograms and implemented a processing system, classifying it into server and data processing. It was conducted as an intermediate-stage research on the implementation of a brain-computer interface using electroencephalograms, and was implemented in the form of predicting the user's arm movements according to measured electroencephalogram data. Electroencephalogram measurements were performed using input from four electrodes through an analog-to-digital converter. After sending this to the server through a communication process, we designed and implemented a system flow in which the server classifies the electroencephalogram input using a convolutional neural network model and displays the results on the user terminal.