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During the COVID-19 outbreak, there was a sharp increase in generalized anxiety disorder (GAD). Acupuncture therapy has the advantages of accurate clinical efficacy, safety and reliability, few adverse reactions, and no dependence, and is gradually becoming one of the emerging therapies for treating GAD. We present a study protocol for a randomized clinical trial with the aim of exploring the mechanism of brain plasticity in patients with GAD and evaluate the effectiveness and reliability of acupuncture treatment. Transcranial magnetic stimulation (TMS) will be used to assess cortical excitability in GAD patients and healthy people. Sixty-six GAD patients meeting the inclusion criteria will be randomly divided into two groups: TA group, (treatment with acupuncture and basic western medicine treatment) and SA group (sham acupuncture and basic western medicine treatment). Twenty healthy people will be recruited as the control group (HC). The parameters that will be evaluated are amplitude of motor evoked potentials (MEPs), cortical resting period (CSP), resting motor threshold (RMT), and Hamilton Anxiety Scale (HAMA) score. Secondary results will include blood analysis of γ-aminobutyric acid (GABA), glutamate (Glu), glutamine (Gln), serotonin (5-HT), and brain-derived nerve growth factor (BDNF). Outcomes will be assessed at baseline and after the intervention (week 8). This study protocol is the first clinical trial designed to detect differences in cerebral cortical excitability between healthy subjects and patients with GAD, and the comparison of clinical efficacy and reliability before and after acupuncture intervention is also one of the main contents of the protocol. We hope to find a suitable non-pharmacological alternative treatment for patients with GAD.
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ObjectiveIn recent years, the negative impact of microgravity on astronauts’ nervous systems has received widespread attention. The repetitive transcranial magnetic stimulation (rTMS) technology has shown significant positive effects in the treatment of neurological and psychiatric disorders. The potential benefits of combined frequency stimulation (CFS) which combines different frequency stimulation patterns in ameliorating neurological dysfunctions induced by the microgravity environment, still require in-depth investigation. Exploring the therapeutic effects and electrophysiological mechanisms of CFS in improving various neurological disorders caused by microgravity holds significant importance for neuroscience and the clinical application of magnetic stimulation. MethodsThis study employed 40 C57BL/6 mice, randomly divided into 5 groups: sham group, hindlimb unloading (HU) group, 10 Hz group, 20 Hz group, and combined frequency stimulation (10 Hz+20 Hz, CFS) group. Mice in all groups except the sham group received 14 d of simulated microgravity conditions along with 14 d of repetitive transcranial magnetic stimulation. The effects of CFS on negative emotions and spatial cognitive abilities were assessed through sucrose preference tests and water maze experiments. Finally, patch-clamp techniques were used to record action potentials, resting membrane potentials, and ion channel dynamics of granule neurons in the hippocampal dentate gyrus (DG) region. ResultsCompared to the single-frequency stimulation group, behavioral results indicated that the combined frequency stimulation (10 Hz+20 Hz) significantly improved cognitive impairments and negative emotions in simulated microgravity mice. Electrophysiological experiments revealed a decrease in excitability of granule neurons in the hippocampal DG region after HU manipulation, whereas the combined frequency stimulation notably enhanced neuronal excitability and improved the dynamic characteristics of voltage-gated Na+ and K+ channels. ConclusionThe repetitive transcranial magnetic stimulation with combined frequencies (10 Hz+20 Hz) effectively ameliorates cognitive impairments and negative emotions in simulated microgravity mice. This improvement is likely attributed to the influence of combined frequency stimulation on neuronal excitability and the dynamic characteristics of Na+ and K+ channels. Consequently, this study holds the promise to provide a theoretical basis for alleviating cognitive and emotional disorders induced by microgravity environments.
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Neuronomodulation refers to the modulation of neural conduction and synaptic transmission (i.e., the conduction process involved in synaptic transmission) of excitable neurons via changes in the membrane potential in response to chemical substances, from spillover neurotransmitters to paracrine or endocrine hormones circulating in the blood. Neuronomodulation can be direct or indirect, depending on the transduction pathways from the ligand binding site to the ion pore, either on the same molecule, i.e. the ion channel, or through an intermediate step on different molecules. The major players in direct neuronomodulation are ligand-gated or voltage-gated ion channels. The key process of direct neuronomodulation is the binding and chemoactivation of ligand-gated or voltage-gated ion channels, either orthosterically or allosterically, by various ligands. Indirect neuronomodulation involves metabotropic receptor-mediated slow potentials, where steroid hormones, cytokines, and chemokines can implement these actions. Elucidating neuronomodulation is of great significance for understanding the physiological mechanisms of brain function, and the occurrence and treatment of diseases.
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Ligands , Neurones/métabolisme , Transmission synaptique/physiologie , Canaux ioniques/métabolisme , Hormones/métabolismeRÉSUMÉ
La estimulación magnética transcraneal (EMT) es una técnica no invasiva que consiste en la utilización de campos magnéticos para estimular a las neuronas de la corteza cerebral. Si bien la electricidad se ha pretendido emplear previamente en el campo de la medicina, la historia de la EMT se remonta al descubrimiento de la inducción electromagnética, por Faraday, en el siglo XIX. Sin embargo, no fue hasta la década de 1980 cuando Anthony Barker, en la Universidad de Sheffield, desarrolló el primer dispositivo de EMT. La EMT funciona mediante una bobina colocada en el cuero cabelludo, la cual produce un campo magnético que puede atravesar el cráneo y estimular las neuronas corticales. La intensidad y la frecuencia del campo magnético pueden ajustarse para dirigirse a zonas específicas del cerebro y producir efectos excitatorios e inhibitorios. Los principios de la EMT se basan en el concepto de neuroplasticidad, que se refiere a la capacidad del cerebro para cambiar y adaptarse en respuesta a nuevas experiencias y estímulos. Al estimular las neuronas del cerebro con la EMT, es posible inducir cambios en la actividad neuronal y la conectividad, lo que a su vez puede provocar cambios cognitivos y en el estado de ánimo.
Transcranial magnetic stimulation (TMS) is a noninvasive technique that uses magnetic fields to stimulate neurons in the cerebral cortex. While electricity has previously been intended to be used in the medical field, the history of TMS dates back to the discovery of electromagnetic induction by Faraday in the 19th century. However, it was not until the 1980s when Anthony Barker developed the first TMS device at the University of Sheffield. TMS works by means of a coil placed against the scalp, thereby producing a magnetic field. This magnetic field can pass through the skull and stimulate cortical neurons. The intensity and frequency of the magnetic field can be adjusted to target specific areas of the brain and produce excitatory and inhibitory effects. The principles of TMS are based on the concept of neuroplasticity, which refers to the brain's ability to change and adapt in response to new experiences and stimuli. By stimulating neurons in the brain with TMS, it is possible to cause changes in neuronal activity and connectivity, which in turn can lead to cognitive and mood changes.
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The optimal protocol for neuromodulation by transcranial direct current stimulation (tDCS) remains unclear. Using the rotarod paradigm, we found that mouse motor learning was enhanced by anodal tDCS (3.2 mA/cm2) during but not before or after the performance of a task. Dual-task experiments showed that motor learning enhancement was specific to the task accompanied by anodal tDCS. Studies using a mouse model of stroke induced by middle cerebral artery occlusion showed that concurrent anodal tDCS restored motor learning capability in a task-specific manner. Transcranial in vivo Ca2+ imaging further showed that anodal tDCS elevated and cathodal tDCS suppressed neuronal activity in the primary motor cortex (M1). Anodal tDCS specifically promoted the activity of task-related M1 neurons during task performance, suggesting that elevated Hebbian synaptic potentiation in task-activated circuits accounts for the motor learning enhancement. Thus, application of tDCS concurrent with the targeted behavioral dysfunction could be an effective approach to treating brain disorders.
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Stimulation transcrânienne par courant continu/méthodes , Cortex moteur/physiologie , Neurones , Stimulation magnétique transcrânienneRÉSUMÉ
ObjectiveTo evaluate the intervention effect of dihydroartemisinin (DHA) on hippocampal nerve injury in L5 spinal nerve ligation (SNL) model and tumor necrosis factor-α (TNF-α) hippocampal continuous injection model. In primary cultured microglia-hippocampal neurons, the regulatory pattern of DHA on microglia-hippocampal neuronal interactions was confirmed. MethodThe experimental animals were divided into Sham group, SNL group, and DHA group (16 mg·kg-1), with 3 mice in each group. The hippocampal CA3 glutamatergic neurons were labeled with adeno-associated virus [Calmodulin-dependent protein kinase Ⅱ(CaMKⅡ) dTomato AAV], and their contributions to the hippocampal CA1, prefrontal cortex (Frc), anterior cortex (ACC), projections of nucleus accumbens (Nac), and Basolateral Amygdala (BLA) were traced by immunofluorescence staining. The experimental animals were divided into a Sham group, a TNF-α hippocampus continuous injection model group, DHA-L, DHA-M, and DHA-H groups (4, 8, 16 mg·kg-1), and pregabalin group (25 mg·kg-1), with 4 mice in each group. The morphology of pyramidal neurons in the hippocampal CA1 and CA3 regions was counted by Golgi staining. The continuous activation of hippocampal primary neurons and microglia was induced, DHA intervention was given by co-culture, and the cell soma area and the expression of postsynaptic density protein 95 (PSD95) inside and outside the primary and secondary dendritic spines of neurons were counted by immunofluorescence. ResultCompared with the Sham group, the projection of CA3 glutamatergic neurons to CA1 region, Frc, and ACC in the SNL group was significantly reduced (P<0.01), while the projection to Nac and BLA was significantly increased (P<0.01). As compared with the SNL group, the projection of hippocampal CA3 glutamatergic neurons to CA1 region, Frc, and ACC was significantly increased in the DHA group (P<0.01), while the projection to Nac and BLA was significantly reduced (P<0.01). Golgi staining results showed that as compared with the Sham group, the density of dendritic spines and the number of dendritic branches in the CA1 and CA3 pyramidal neurons in the TNF-α hippocampal continuous injection model group were significantly reduced (P<0.01). As compared with the TNF-α hippocampal continuous injection model, the density of dendritic spines and the number of dendritic branches in hippocampal CA1 and CA3 pyramidal neurons in the DHA-M and DHA-H groups were significantly increased (P<0.05, P<0.01). Compared with DHA-M group, the total dendrite length of CA1 pyramidal neurons in hippocampus in DHA-H group was significantly increased (P<0.01), while the total dendrite length of CA1 neurons and the total dendrite base length of CA3 neurons in DHA-L group was significantly decreased (P<0.01). Compared with the blank control group, the cell soma area of the glycine group and glutamate group increased significantly (P<0.01). As compared with the glycine group and glutamate group, the cell area of the glycine + glutamate group was significantly increased (P<0.01), and as compared with the glutamate group, the cell soma area of the glutamate + DHA group was significantly reduced (P<0.01). As compared with the glycine acid + glutamate group, the cell soma area of the glycine + glutamate + DHA group was significantly reduced (P<0.01), and as compared with the glutamate + DHA group, the cell soma area of the glycine + glutamate + DHA group was also significantly reduced (P<0.05). Compared with the blank control group, the cell soma area of the glutamate group was significantly increased (P<0.01). As compared with the glutamate group, the cell soma area of the glutamate + DHA-L, glutamate + DHA-M, and glutamate + DHA-H groups was significantly reduced (P<0.01). As compared with the blank control group, the expression of the resting primary microglia + glycine group in primary and secondary dendritic internal and external postsynaptic density protein 95 (PSD95) was significantly increased (P<0.01). As compared with the resting primary microglia + glycine group, the expression of PSD95 in the primary and secondary dendritic spinous and external neurons of the activated primary microglia + glycine group was significantly reduced (P<0.01). As compared with the activated primary microglia + glycine group, the expression of PSD95 in the primary and secondary dendritic spinous and external neurons in the activated primary microglia + glycine + DHA group was significantly increased (P<0.01). As compared with the activated primary microglia + DHA group, the expression of PSD95 in the primary and secondary dendritic spines and outside neurons in the activated primary microglia + glycine + DHA group was significantly increased (P<0.01). ConclusionDHA has a significant repair effect on vertebral neuronal damage caused by hippocampal microglia and TNF-α overexpression in NP pathology, and this repair is closely related to the dual inhibition of neuronal-microglia by DHA.
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OBJECTIVE@#To observe the effect of Shugan Tiaoshen acupuncture (acupuncture for soothing the liver and regulating the mentality) combined with western medication on depression and sleep quality in the patients with depression-insomnia comorbidity due to COVID-19 quarantine, and investigate the potential mechanism from the perspective of cortical excitability.@*METHODS@#Sixty patients with depression-insomnia comorbidity due to COVID-19 quarantine were randomly divided into an acupuncture group and a sham-acupuncture group, 30 cases in each one. The patients of both groups were treated with oral administration of sertraline hydrochloride tablets. In the acupuncture group, Shugan Tiaoshen acupuncture was supplemented. Body acupuncture was applied to Yintang (GV 24+), Baihui (GV 20), Hegu (LI 4), Zhaohai (KI 6), Qihai (CV 6), etc. The intradermal needling was used at Xin (CO15), Gan (CO12) and Shen (CO10). In the sham-acupuncture group, the sham-acupuncture was given at the same points as the acupuncture group. The compensatory treatment was provided at the end of follow-up for the patients in the sham-acupuncture group. In both groups, the treatment was given once every two days, 3 times a week, for consecutive 8 weeks. The self-rating depression scale (SDS) and insomnia severity index (ISI) scores were compared between the two groups before and after treatment and 1 month after the end of treatment (follow-up) separately. The cortical excitability indexes (resting motor threshold [rMT], motor evoked potential amplitude [MEP-A], cortical resting period [CSP]) and the level of serum 5-hydroxytryptamine (5-HT) were measured before and after treatment in the two groups.@*RESULTS@#After treatment and in follow-up, SDS and ISI scores were decreased in both groups compared with those before treatment (P<0.05), and the scores in the acupuncture group were lower than those in the sham-acupuncture group (P<0.05), and the decrease range in the acupuncture group after treatment was larger than that in the sham-acupuncture group (P<0.05). After treatment, rMT was reduced (P<0.05), while MEP-A and CSP were increased (P<0.05) in the acupuncture group compared with that before treatment. The levels of serum 5-HT in both groups were increased compared with those before treatment (P<0.05). The rMT in the acupuncture group was lower than that in the sham-acupuncture group, while MEP-A and CSP, as well as the level of serum 5-HT were higher in the acupuncture group in comparison with the sham-acupuncture group (P<0.05).@*CONCLUSION@#Shugan Tiaoshen acupuncture combined with western medication can relieve depression and improve sleep quality in the patients with depression-insomnia comorbidity due to COVID-19 quarantine, which is probably related to rectifying the imbalanced excitatory and inhibitory neuronal functions.
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Humains , Dépression , Quarantaine , Sérotonine , Troubles de l'endormissement et du maintien du sommeil , COVID-19 , Thérapie par acupuncture , ComorbiditéRÉSUMÉ
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.
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Animaux , Souris , Stimulation magnétique transcrânienne , Suspension des membres postérieurs , Neurones , Dysfonctionnement cognitif , EncéphaleRÉSUMÉ
OBJECTIVES@#To compare the effects of electroacupuncture (EA) with different time intervals on corticospinal excitability of the primary motor cortex (M1) and the upper limb motor function in healthy subjects and observe the after-effect rule of acupuncture.@*METHODS@#Self-comparison before and after intervention design was adopted. Fifteen healthy subjects were included and all of them received three stages of trial observation, namely EA0 group (received one session of EA), EA6h group (received two sessions of EA within 1 day, with an interval of 6 h) and EA48h group (received two sessions of EA within 3 days, with an interval of 48 h). The washout period among stages was 1 week. In each group, the needles were inserted perpendicularly at Hegu (LI 4) on the left side, 23 mm in depth and at a non-acupoint, 0.5 cm nearby to the left side of Hegu (LI 4), separately. Han's acupoint nerve stimulator (HANS-200A) was attached to these two needles, with continuous wave and the frequency of 2 Hz. The stimulation intensity was exerted higher than the exercise threshold (local muscle twitching was visible, and pain was tolerable by healthy subjects, 1-2 mA ). The needles were retained for 30 min. Using the single pulse mode of transcranial magnetic stimulation (TMS) technique, before the first session of EA (T0) and at the moment (T1), in 2 h (T2) and 24 h (T3) after the end of the last session of EA, on the left first dorsal interosseous muscle, the amplitude, latency (LAT), resting motor threshold (rMT) of motor evoked potentials (MEPs) and the completion time of grooved pegboard test (GPT) were detected. Besides, in the EA6h group, TMS was adopted to detect the excitability of M1 (amplitude, LAT and rMT of MEPs) before the last session of EA (T0*).@*RESULTS@#The amplitude of MEPs at T1 and T2 in the EA0 group, at T0* in the EA6h group and at T1, T2 and T3 in the EA48h group was higher when compared with the value at T0 in each group separately (P<0.001). At T1, the amplitude of MEPs in the EA0 group and the EA48h group was higher than that in the EA6h group (P<0.001, P<0.01); at T2, it was higher in the EA0 group when compared with that in the EA6h group (P<0.01); at T3, the amplitude in the EA0 group and the EA6h group was lower than that of the EA48h group (P<0.001). The LAT at T1 was shorter than that at T0 in the three groups (P<0.05), and the changes were not obvious at the rest time points compared with that at T0 (P > 0.05). The GPT completion time of healthy subjects in the EA0 group and the EA48h group at T1, T2 and T3 was reduced in comparison with that at T0 (P<0.001). The completion time at T3 was shorter than that at T0 in the EA6h group (P<0.05); at T2, it was reduced in the EA48h group when compared with that of the EA6h group (P<0.05). There were no significant differences in rMT among the three groups and within each group (P>0.05).@*CONCLUSIONS@#Under physiological conditions, EA has obvious after-effect on corticospinal excitability and upper limb motor function. The short-term interval protocol (6 h) blocks the after-effect of EA to a certain extent, while the long-term interval protocol (48 h) prolongs the after-effect of EA.
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Humains , Électroacupuncture , Cortex moteur/physiologie , Stimulation magnétique transcrânienne/méthodes , Membre supérieur , Exercice physique , Muscles squelettiques/physiologieRÉSUMÉ
Acetylcholine (ACh) is an important neuromodulator in various cognitive functions. However, it is unclear how ACh influences neural circuit dynamics by altering cellular properties. Here, we investigated how ACh influences reverberatory activity in cultured neuronal networks. We found that ACh suppressed the occurrence of evoked reverberation at low to moderate doses, but to a much lesser extent at high doses. Moreover, high doses of ACh caused a longer duration of evoked reverberation, and a higher occurrence of spontaneous activity. With whole-cell recording from single neurons, we found that ACh inhibited excitatory postsynaptic currents (EPSCs) while elevating neuronal firing in a dose-dependent manner. Furthermore, all ACh-induced cellular and network changes were blocked by muscarinic, but not nicotinic receptor antagonists. With computational modeling, we found that simulated changes in EPSCs and the excitability of single cells mimicking the effects of ACh indeed modulated the evoked network reverberation similar to experimental observations. Thus, ACh modulates network dynamics in a biphasic fashion, probably by inhibiting excitatory synaptic transmission and facilitating neuronal excitability through muscarinic signaling pathways.
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Agents cholinergiques/pharmacologie , Acétylcholine/métabolisme , Neurones/métabolisme , Transmission synaptique/physiologieRÉSUMÉ
Alzheimer′s disease (AD), a progressive neurodegenerative disease, is characterized by dysfunction in execution and cognition, for which there are few efficient early interventions. Synaptic plasticity is regarded as a critical mechanism for learning and memory. Therefore, improving synaptic plasticity is correlated with promoting recovery after cognitive and motor impairment in patients with AD. Repetitive transcranial magnetic stimulation (rTMS) has been extensively utilized in AD rehabilitation for its potential to yield significant and enduring benefits in neural excitability and plasticity. This review overviews synaptic dysfunction in AD and primarily discusses the role of rTMS in alleviating clinical symptoms by influencing structural and functional plasticity of synapses, to explore its mechanisms for the treatment of neuropsychiatric disorders, and at the same time, provide clues and directions for further clinical translations.
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Epilepsy is a disorder of the brain charac-terized by abnormal neuron excitability.However,the underlying molecular mechanism of neuron excitability modulation remains elusive.With the help of bioinformatic methods,we have identified receptor-type tyrosine-pro-tein phosphatase-like N(PTPRN)as a critical gene dur-ing epileptogenesis.PTPRN recruits NEDD4L ubiquitin E3 ligase to NaV1.2 sodium channels,facilitating NEDD4L-mediated ubiquitination and endocytosis.Knockout of PTPRN endows hippocampal granule cells with augmented depolarization currents and higher intrinsic excitability,which is reflected by increased seizure susceptibility of transgenic mice.On the contrary,reduced neuron excit-ability and decreased seizure susceptibility are observed after PTPRN overexpression.Meanwhile,we find that a 133 aa fragment recaptures modulation effect of PTPRN full-length,and this fragment shows therapeutic potential towards epilepsy caused by NaV1.2 gain of function vari-ants.In brief,our results demonstrate PTPRN playsa criti-calroleinregulatingneuronexcitability,providing a poten-tial therapeutic approach for epilepsy.
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Objective:To further elucidate the pathogenesis of hemifacial spasm by analyzing blinking reflex characteristics.Methods:A total of 63 patients with hemifacial spasm (hemifacial spasm group) who underwent neuroelectrophysiological evaluation in Department of Neurological Electrophysiology, Guizhou Provincial People's Hospital from January 2021 to December 2022 were included as study subjects. Additionally, 58 patients with primary trigeminal neuralgia (trigeminal neuralgia group), 8 patients with post-facial paralysis associated exercise (post-facial paralysis associated exercise group), and 20 healthy volunteers (normal group) were selected as controls. Differences in facial nerve motor conduction velocity, complex muscle action potential latency, and blinking reflex characteristics including R1 latency, R1 amplitude, R2 initiation latency, R2 amplitude, R2 terminal latency, R2' initiation latency recorded on the affected side, R2' amplitude recorded on the affected side, and R2' terminal latency recorded on the affected side were collected and compared. Severity of hemifacial spasm was graded from grade 1 to grade 4 according to Samsung Medical Center scoring system; based on microvascular decompression findings regarding responsible blood vessels contacted with the facial nerve, patients were divided into one responsible blood vessel group and two or more responsible blood vessels group; trends or differences in incidences of increased/prolonged blink reflex indexes among all groups were analyzed.Results:No significant difference in facial nerve motor conduction velocity or complex muscle action potential latency was noted among the 4 groups ( P>0.05); the hemifacial spasm group had significantly higher R1 amplitude than the trigeminal neuralgia group and post-facial paralysis associated exercise group; additionally, the hemifacial spasm group had significantly higher R2 amplitude, R2' amplitude recorded on the affected side, R2 terminal latency, and R2' terminal latency recorded on the affected side compared with the other 3 groups ( P<0.05). Among patients with varying degrees of hemifacial spasm, increased incidences of increased R1 amplitude and prolonged R2 terminal latency were noted with increased spasm degrees, enjoying significant differences ( P<0.05). No significant differences in incidences of increased R1 amplitude, increased R2 amplitude, prolonged R2 terminal latency, increased R2' amplitude recorded on the affected side or prolonged R2' terminal latency recorded on the affected side were noted between one responsible blood vessel group and two or more responsible blood vessels group ( P>0.05). Conclusion:Increased R1 amplitude and prolonged R2 latency in patients with hemifacial spasm further substantiate the pathogenesis of hyperexcitability within facial nerve nucleus.
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Epilepsy is a common neurological disorder characterized by hyperexcitability in the brain. Its pathogenesis is classically associated with an imbalance of excitatory and inhibitory neurons. Calretinin (CR) is one of the three major types of calcium-binding proteins present in inhibitory GABAergic neurons. The functions of CR and its role in neural excitability are still unknown. Recent data suggest that CR neurons have diverse neurotransmitters, morphologies, distributions, and functions in different brain regions across various species. Notably, CR neurons in the hippocampus, amygdala, neocortex, and thalamus are extremely susceptible to excitotoxicity in the epileptic brain, but the causal relationship is unknown. In this review, we focus on the heterogeneous functions of CR neurons in different brain regions and their relationship with neural excitability and epilepsy. Importantly, we provide perspectives on future investigations of the role of CR neurons in epilepsy.
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Humains , Amygdale (système limbique)/métabolisme , Calbindine-2/métabolisme , Épilepsie , Neurones GABAergiques , Hippocampe/métabolismeRÉSUMÉ
Ischemic brain stroke is pathologically characterized by tissue acidosis, sustained calcium entry and progressive cell death. Previous studies focusing on antagonizing N-methyl-d-aspartate (NMDA) receptors have failed to translate any clinical benefits, suggesting a non-NMDA mechanism involved in the sustained injury after stroke. Here, we report that inhibition of intracellular proton-sensitive Ca2+-permeable transient receptor potential vanilloid 3 (TRPV3) channel protects against cerebral ischemia/reperfusion (I/R) injury. TRPV3 expression is upregulated in mice subjected to cerebral I/R injury. Silencing of TRPV3 reduces intrinsic neuronal excitability, excitatory synaptic transmissions, and also attenuates cerebral I/R injury in mouse model of transient middle cerebral artery occlusion (tMCAO). Conversely, overexpressing or re-expressing TRPV3 increases neuronal excitability, excitatory synaptic transmissions and aggravates cerebral I/R injury. Furthermore, specific inhibition of TRPV3 by natural forsythoside B decreases neural excitability and attenuates cerebral I/R injury. Taken together, our findings for the first time reveal a causative role of neuronal TRPV3 channel in progressive cell death after stroke, and blocking overactive TRPV3 channel may provide therapeutic potential for ischemic brain injury.
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The family of voltage-gated potassium Kv2 channels consists of the Kv2.1 and Kv2.2 subtypes. Kv2.1 is constitutively highly phosphorylated in neurons and its function relies on its phosphorylation state. Whether the function of Kv2.2 is also dependent on its phosphorylation state remains unknown. Here, we investigated whether Kv2.2 channels can be phosphorylated by protein kinase C (PKC) and examined the effects of PKC-induced phosphorylation on their activity and function. Activation of PKC inhibited Kv2.2 currents and altered their steady-state activation in HEK293 cells. Point mutations and specific antibodies against phosphorylated S481 or S488 demonstrated the importance of these residues for the PKC-dependent modulation of Kv2.2. In layer II pyramidal neurons in cortical slices, activation of PKC similarly regulated native Kv2.2 channels and simultaneously reduced the frequency of action potentials. In conclusion, this study provides the first evidence to our knowledge that PKC-induced phosphorylation of the Kv2.2 channel controls the excitability of cortical pyramidal neurons.
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Humains , Potentiels d'action , Cellules HEK293 , Protéine kinase C/métabolisme , Cellules pyramidales/enzymologie , Canaux potassiques Shab/génétiqueRÉSUMÉ
There is a close association between sleep and epilepsy, and this literature review aims to raise issues regarding sleep time control, circadian and ultradian rhythms, epilepsy and its interaction with sleep and circadian rhythm, epilepsy and sleep disorders, and finally epilepsy management and medications. It is mentioned that sleep may provide a hypersynchronous state, as occurs in non-rapid eye movement sleep (NREM), and hyperexcitability, in cyclic alternating pattern (CAP), allowing more frequent interictal epileptiform abnormalities and seizures. In some epilepsy syndromes, seizures occur broadly / or entirely during sleep or on awakening, mainly in childhood, and maybe exacerbated in adults during the sleep or sleep-deprived, and there are the so-called Sleep-related epilepsies that are divided as sleep-associated, sleep-accentuated and arousal/awakening related. Sleep quality may be reduced in patients with epilepsy also due to nocturnal seizures or concomitant sleep disorders. Sleep disorders are common in patients with epilepsy and treatment of them mainly sleep-disordered breathing may improve seizure control. Besides, some parasomnias may mimic seizures, and also they can adversely affect the quality and quantity of sleep whereas antiepileptic therapy can have a negative or positive effect on sleep. Nocturnal epileptic seizures may be challenging to discern from parasomnias, in particular NREM parasomnias such as night terrors, sleepwalking and confusional arousals.
Há uma estreita associação entre sono e epilepsia, e esta revisão de literatura tem como objetivo levantar questões relacionadas ao controle do tempo do sono, ritmos circadianos e ultradianos, epilepsia e sua interação com sono e ritmo circadiano, epilepsia e transtornos do sono e, finalmente, o tratamento e medicamentos para epilepsia. Menciona-se que o sono pode proporcionar um estado hipersincrônico, como ocorre no sono "non-rapid eye movement" (NREM), e hiperexcitabilidade, no "cyclic alternating pattern" (CAP), permitindo anormalidades epileptiformes interictais e crises epilépticas mais frequentes. Em algumas síndromes epilépticas, as crises ocorrem ampla / ou inteiramente durante o sono ou despertar, principalmente na infância, e podem ser exacerbadas em adultos durante o sono ou privação de sono, e as chamadas epilepsias relacionadas ao sono se dividem em sono associadas, sono acentuadas e relacionadas com o despertar. A qualidade do sono pode ser reduzida em pacientes com epilepsia também devido a crises epilépticas noturnas ou transtornos do sono concomitantes. Esses são comuns em pacientes com epilepsia e o seu tratamento, principalmente dos transtornos respiratórios do sono, pode melhorar o controle das crises epilépticas. Além disso, algumas parassonias podem mimetizar crises epilépticas, e também elas podem afetar adversamente a qualidade e a quantidade do sono, enquanto a terapia antiepiléptica pode ter um efeito negativo ou positivo sobre o sono. Pode ser difícil discernir as crises epilépticas noturnas das parassonias, em particular das parassonias NREM, como terrores noturnos, crises de sonambulismo e despertares confusionais.
Sujet(s)
Humains , Enfant , Adulte , Privation de sommeil , Troubles de la veille et du sommeil/étiologie , Épilepsie/complications , Épilepsie/diagnostic , Crises épileptiques/étiologie , Troubles de la veille et du sommeil/complications , Rythme circadien , Épilepsie/traitement médicamenteuxRÉSUMÉ
The nervous system controls eccentric exercise in a special way. During eccentric exercise, excitability increases in cortex, and inhibition decreases, causing excitability decrease in spinal cords. In another hand, increased cortical excitability results in extra excitatory compensation for spinal inhibition. The excitability of the corticospinal pathway depends on the balance between excitability and inhibition of the spinal cord level finally, which usually decreases. Many factors, such as the intensity of contraction, can affect the balance of corticospinal excitability. There is a cross-over effect in eccentric exercise, which promotes corticospinal excitability in untrained limbs. However, the effects and mechanisms of muscle length, fatigue and training duration are still unclear, and current researches have focused in the healthy populations. More researches are needed to explore the effects of eccentric exercise on ill populations.
RÉSUMÉ
Substances addiction is one of the important factors that deeply affect human health.At present, there is still lack of effective treatment drugs in the clinic.Exploring mechanisms of substances addiction, finding new therapeutic targets and developing effective therapeutic drugs are important issues to be solved.Hyperpolarization-activated cyclic nucleotide gated cation channels (HCN channels) participate in many advanced brain activities and are closely related to the occurrence and progression of various brain diseases.Among them, the researches on the role and mechanism of HCN channels in substances addiction are gradually gaining attention.Reviewing the researches regarding substances addiction, abnormal function and abnormal expression of HCN channels were observed in many brain regions under the condition of psychoactive substances addiction.However, it has not yet been able to fully understand the mechanism and the behavioral consequences of this change.Therefore, we review the neurobiological mechanisms of HCN channels in substances addiction induced by opioids, cocaine, cannabis, amphetamines, alcohol and tobacco, in order to provide new ideas for the mechanism researches and treatment of substance addiction.
RÉSUMÉ
OBJECTIVE@#To compare the effect of electroacupuncture (EA), motor training (MT) and EA combined with MT on motor learning and motor cortex excitability in healthy subjects, and to explore the effect of EA combined with MT on synaptic metaplasticity.@*METHODS@#Using self-control design, 12 healthy subjects were assigned into an EA group, a motor training group (MT group) and an EA plus motor training group (EA+MT group) successively, wash-out period of at least 2 weeks was required between each group. EA was applied at left Hegu (LI 4) in the EA group for 30 min, with continuous wave, 2 Hz in frequency and 0.5-1 mA in density. Motor training of left hand was adopted in the MT group for 30 min. EA and motor training were adopted in the EA+MT group successively. The time of finishing grooved pegboard test (GPT) was observed, and the average amplitude of motor evoked potentials (MEPs), the rest motor threshold (rMT) and the latency were recorded by transcranial magnetic stimulation technique before intervention (T0), after intervention (T1) and 30 min after EA (T3) in the EA group and the EA+MT group, T0 and T1 in the MT group.@*RESULTS@#Compared with T0, the time of finishing GPT was shortened at T1 in the MT group and at T2 in the EA group and the EA+MT group (@*CONCLUSION@#In physiological state, electroacupuncture combined with motor training have a synergistic effect on motor learning, while have no such effect on excitability of cerebral motor cortex.