ABSTRACT
Weightlessness in the space environment affects astronauts' learning memory and cognitive function. Repetitive transcranial magnetic stimulation has been shown to be effective in improving cognitive dysfunction. In this study, we investigated the effects of repetitive transcranial magnetic stimulation on neural excitability and ion channels in simulated weightlessness mice from a neurophysiological perspective. Young C57 mice were divided into control, hindlimb unloading and magnetic stimulation groups. The mice in the hindlimb unloading and magnetic stimulation groups were treated with hindlimb unloading for 14 days to establish a simulated weightlessness model, while the mice in the magnetic stimulation group were subjected to 14 days of repetitive transcranial magnetic stimulation. Using isolated brain slice patch clamp experiments, the relevant indexes of action potential and the kinetic property changes of voltage-gated sodium and potassium channels were detected to analyze the excitability of neurons and their ion channel mechanisms. The results showed that the behavioral cognitive ability and neuronal excitability of the mice decreased significantly with hindlimb unloading. Repetitive transcranial magnetic stimulation could significantly improve the cognitive impairment and neuroelectrophysiological indexes of the hindlimb unloading mice. Repetitive transcranial magnetic stimulation may change the activation, inactivation and reactivation process of sodium and potassium ion channels by promoting sodium ion outflow and inhibiting potassium ion, and affect the dynamic characteristics of ion channels, so as to enhance the excitability of single neurons and improve the cognitive damage and spatial memory ability of hindlimb unloading mice.
Subject(s)
Animals , Mice , Transcranial Magnetic Stimulation , Hindlimb Suspension , Neurons , Cognitive Dysfunction , BrainABSTRACT
Objective:To explore the effect of repeated magnetic stimulation (rMS) on the growth and differentiation of SH-SY5Y human neuroblastoma cells.Methods:SH-SY5Y cells were subjected to rMS at 15%, 30% and 60% of the maximum output intensity at frequencies of 0.5Hz, 1Hz, 5Hz, 10Hz and 20Hz. They received either 800 or 1600 pulses per day for 4 days. Cell viability was detected using the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl-2H-tetrazolium bromide (MTT) assay. Apoptosis was induced using 1-methyl-4-phenylpyridine ion (MPP + ) and all-trans retinoic acid was used to induce differentiation. The expression of neuron-specific nuclear proteins and the degree of cell differentiation were observed by immunohistochemistry. Results:0.5Hz rMS inhibited proliferation and 10Hz rMS promoted it. With 5Hz rMS significantly greater cell proliferation was observed at 15% and 30% of the maximum output intensity. The stimulatory effect of 1600 pulses per day was significantly greater than that of 800 pulses, especially at 10Hz. Apoptosis was inhibited at both 0.5Hz and 10Hz with 30% of the maximum output intensity. Meanwhile, both 0.5Hz and 10Hz rMS promoted differentiation of the SH-SY5Y cells into neurons.Conclusions:rMS at low frequency inhibits the proliferation of SH-SY5Y cells, but at higher frequency it promotes it. The effect strengthens with more pulses administered. rMS has a protective effect on MPP + -induced SH-SY5Y apoptosis, and it can promote the cells′ differentiation into neurons.
ABSTRACT
Transcranial magnetic stimulation (TMS) as a noninvasive neuromodulation technique can improve the impairment of learning and memory caused by diseases, and the regulation of learning and memory depends on synaptic plasticity. TMS can affect plasticity of brain synaptic. This paper reviews the effects of TMS on synaptic plasticity from two aspects of structural and functional plasticity, and further reveals the mechanism of TMS from synaptic vesicles, neurotransmitters, synaptic associated proteins, brain derived neurotrophic factor and related pathways. Finally, it is found that TMS could affect neuronal morphology, glutamate receptor and neurotransmitter, and regulate the expression of synaptic associated proteins through the expression of brain derived neurotrophic factor, thus affecting the learning and memory function. This paper reviews the effects of TMS on learning, memory and plasticity of brain synaptic, which provides a reference for the study of the mechanism of TMS.
Subject(s)
Humans , Brain , Learning , Neuronal Plasticity , Transcranial Magnetic StimulationABSTRACT
As a noninvasive neuromodulation technique, transcranial magnetic stimulation (TMS) is widely used in the clinical treatment of neurological and psychiatric diseases, but the mechanism of its action is still unclear. The purpose of this paper is to investigate the effects of different frequencies of magnetic stimulation (MS) on neuronal excitability and voltage-gated potassium channels in the
Subject(s)
Animals , Mice , Action Potentials , Magnetic Phenomena , Mental Disorders , Neurons , Patch-Clamp Techniques , Potassium Channels, Voltage-GatedABSTRACT
With the wide application of deep learning technology in disease diagnosis, especially the outstanding performance of convolutional neural network (CNN) in computer vision and image processing, more and more studies have proposed to use this algorithm to achieve the classification of Alzheimer's disease (AD), mild cognitive impairment (MCI) and normal cognition (CN). This article systematically reviews the application progress of several classic convolutional neural network models in brain image analysis and diagnosis at different stages of Alzheimer's disease, and discusses the existing problems and gives the possible development directions in order to provide some references.
Subject(s)
Humans , Alzheimer Disease/diagnostic imaging , Cognitive Dysfunction/diagnosis , Image Processing, Computer-Assisted , Magnetic Resonance Imaging , Neural Networks, ComputerABSTRACT
Repetitive transcranial magnetic stimulation (rTMS) is a noninvasive brain stimulation technique that has been paid attention to with increasing interests as a therapeutic neural rehabilitative tool. Studies confirmed that high-frequency rTMS could improve the cognitive performance in behavioral test as well as the excitability of the neuron in animals. This study aimes to investigate the effects of rTMS on the cognition and neuronal excitability of Kunming mice during the natural aging. Twelve young mice, 12 adult mice, and 12 aged mice were used, and each age group were randomly divided into rTMS group and control group. rTMS-treated groups were subjected to high-frequency rTMS treatment for 15 days, and control groups were treated with sham stimulation for 15 days. Then, novel object recognition and step-down tests were performed to examine cognition of learning and memory. Whole-cell patch clamp technique was used to record and analyze resting membrane potential, action potential (AP), and related electrical properties of AP of hippocampal dentate gyrus (DG) granule neurons. Data analysis showed that cognition of mice and neuronal excitability of DG granule neurons were degenerated significantly as the age increased. Cognitive damage and degeneration of some electrical properties were alleviated under the condition of high-frequency rTMS. It may be one of the mechanisms of rTMS to alleviate cognitive damage and improve cognitive ability by changing the electrophysiological properties of DG granule neurons and increasing neuronal excitability.
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Objective: Adiponectin (APN) is an endogenous cytokine that mediates the development and progression of various tumors through its receptors (AdipoRs). The present study aimed to detect the expression and distribution of APN and its receptors (AdipoR1 and AdipoR2) in tongue squamous cell carcinoma (TSCC). Moreover, we explored whether the locoregional expression of APN was reg-ulated by HIF-1α in the hypoxic microenvironment. Methods: The expression and distribution of APN and its receptors in TSCC tissues were analyzed by immunohistochemical. Lentiviral expression vector for HIF-1α shRNA was constructed and stably transfected in TSCC cells to knock down HIF-1α expression. The mRNA and protein expression levels of APN and its receptors were detected using RT-PCR and Western blot, respectively, after hypoxic treatment. Results: The locoregional expression of APN and AdipoR1, but not AdipoR2, was upregulated at the early stages of T1, T2, and/or N0 stage, respectively, in tumor tissues compared to that in control paracancer-ous tissues (P<0.05 or P<0.01). The expression of APN and AdipoR1, but not AdipoR2, in TSCC cells was up-regulated on hypoxic treat-ment. Moreover, the expression of APN and AdipoR1 was down-regulated after shRNA knockdown of HIF-1α under hypoxia. Conclu-sions: The APN-AdipoR1 signaling pathway was activated and regulated by HIF-1α in the hypoxic environment of TSCC tissues.
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Objective@#To compare the general biological characteristics and the expressions of proteins involved in secretion in stem cells from the pulp of human exfoliated deciduous teeth (SHED) and dental pulp stem cells (DPSC).@*Methods@#SHED and DPSC were cultured and collected at passage 4 (P4) and P7. The submandibular gland epithelial and interstitial cells were cultured with tissue culture method. The cell morphology was observed using a phase contrast microscope. Flow cytometry was used to detect stem cell surface markers. Cell counting kit-8 (CCK-8) and IncuCyte ZOOM were used to evaluate cell proliferation. Quantitative real-time PCR (qPCR) was performed to examine the mRNA expressions of proteins involved in fluid and protein secretion.@*Results@#P4 and P7 SHED and DPSC were spindle-shaped. There was no difference in cell morphology among the 4 group cells. P4 and P7 SHED and DPSC expressed CD29, CD44, CD73, and CD90, the mesenchymal stem cell markers, while, CD49f and CD117, the epithelium markers were undetected. There was no difference in cell proliferation among the 4 group cells. Compared with P4 SHED, the expressions of muscarinic cholinergic receptor 1 (MR1), MR3, aquaporin 5 (AQP5), β1-adrenoceptor (β1-AR), α-amylase, and mucin 5B in SHED were not different, while β2-AR expression was decreased (P<0.05). Compared with P4 DPSC, the expressions of MR3, β2-AR, and α-amylase in P7 DPSC were not different, while, the expressions of MR1, AQP5, β1-AR, and mucin 5B were decreased (P<0.05). Compared with primary cultured submandibular gland epithelial cells and gland tissues from a child, the expressions of proteins involved in secretion were all decreased. Compared with submandibular epithelial cells from adults, the expression of AQP5 in P4 DPSC was decreased (P<0.05), while other proteins were not different. The expressions of AQP5, β1-AR, α-amylase and mucin 5B in P7 DPSC were increased (P<0.05), while other proteins were not different. In P4 and P7 DPSC, all the protein expression levels were decreased, compared with those in submandibular gland tissues (P<0.01).@*Conclusions@#Compared with DPSC, SHED have stable growth and the expressions of protein involved fluid and protein secretion are low. Based on its extensive sources and easy separation, SHED can be used as the ideal seed cell for salivary gland tissue engineering and the treatment of salivary gland hypofunction, and the P4 to P7 SHED can be used for experimental study.
ABSTRACT
To investigate the effect of naringenin on ovariectomy-induced postmenopausal osteoporosis comprehensively and systemically, thirty-two virgin Sprague-Dawley rats about 3-month-old were used and randomly divided into 4 groups: sham control group (Sham), OVX control group (OVX), naringenin treatment group and 17β-estradiol (E2) treatment group. After 12 weeks treatment with different drugs, 24 h urine were collected, organs were weighed and the organ indies were computed. Uterine pathological changes were observed by making paraffin section. Biochemical parameters and bone turnover markers: serum osteocalcin (BGP) and urine deoxypyridinoline (DPD) were analyzed with automatic biochemical analyzer or ELISA assay. Bone mineral density (BMD) and bone mineral content (BMC) were analyzed by DEXA, bone biomechanical properties was measured by three point bending test and the trabecular bone microarchitecture was evaluated by Micro CT. From the results, we can see that: the gaining of weight and the increasing of bone turnover markers such as serum BGP and urinary DPD could be inhibited by naringenin. The treatment could also enhance the bone strength and prevent the deterioration of trabecular microarchitecture, increase the bone volume, trabecular number and thickness, and decrease the trabecular space. The effects mentioned above were not accompanied with stimulating effects on uterus. Long-term using of naringenin had no obvious influence on other organs and the liver and kidney functions. The study suggests that naringenin had obvious antiosteoporotic effect on ovariectomized rats and it had the potential value for the treatment of postmenopausal osteoporosis.
ABSTRACT
To investigate the effect of naringenin on ovariectomy-induced postmenopausal osteoporosis comprehensively and systemically, thirty-two virgin Sprague-Dawley rats about 3-month-old were used and randomly divided into 4 groups: sham control group (Sham), OVX control group (OVX), naringenin treatment group and 17β-estradiol (E2) treatment group. After 12 weeks treatment with different drugs, 24 h urine were collected, organs were weighed and the organ indies were computed. Uterine pathological changes were observed by making paraffin section. Biochemical parameters and bone turnover markers: serum osteocalcin (BGP) and urine deoxypyridinoline (DPD) were analyzed with automatic biochemical analyzer or ELISA assay. Bone mineral density (BMD) and bone mineral content (BMC) were analyzed by DEXA, bone biomechanical properties was measured by three point bending test and the trabecular bone microarchitecture was evaluated by Micro CT. From the results, we can see that: the gaining of weight and the increasing of bone turnover markers such as serum BGP and urinary DPD could be inhibited by naringenin. The treatment could also enhance the bone strength and prevent the deterioration of trabecular microarchitecture, increase the bone volume, trabecular number and thickness, and decrease the trabecular space. The effects mentioned above were not accompanied with stimulating effects on uterus. Long-term using of naringenin had no obvious influence on other organs and the liver and kidney functions. The study suggests that naringenin had obvious antiosteoporotic effect on ovariectomized rats and it had the potential value for the treatment of postmenopausal osteoporosis.
Subject(s)
Animals , Female , Rats , Amino Acids , Urine , Bone Density , Disease Models, Animal , Estradiol , Pharmacology , Estrogen Antagonists , Pharmacology , Flavanones , Pharmacology , Osteocalcin , Blood , Osteoporosis , Drug Therapy , Ovariectomy , Rats, Sprague-Dawley , Uterus , PathologyABSTRACT
In order to investigate in greater detail the two methods based on Hertz model for analyzing force-distance curve obtained by atomic force microscopy, we acquired the force-distance curves of Hela and MCF-7 cells by atomic force microscopy (AFM) indentation in this study. After the determination of contact point, Young's modulus in different indentation depth were calculated with two analysis methods of "two point" and "slope fitting". The results showed that the Young's modulus of Hela cell was higher than that of MCF-7 cell,which is in accordance with the F-actin distribution of the two types of cell. We found that the Young's modulus of the cells was decreased with increasing indentation depth and the curve trends by "slope fitting". This indicated that the "slope fitting" method could reduce the error caused by the miscalculation of contact point. The purpose of this study was to provide a guidance for researcher to choose an appropriate method for analyzing AFM indentation force-distance curve.