3,376 results match your criteria pulse facilitation

Dosage-dependent impact of acute serotonin enhancement on transcranial direct current stimulation effects.

Int J Neuropsychopharmacol 2021 Jun 9. Epub 2021 Jun 9.

Department of Psychology and Neurosciences, Leibniz Research Centre for Working Environment and Human Factors (IfADo), Dortmund, Germany.

Background: The serotonergic system has an important impact on basic physiological and higher brain functions. Acute and chronic enhancement of serotonin levels via selective serotonin reuptake inhibitor (SSRI) administration impacts neuroplasticity in humans, as shown by its effects on cortical excitability alterations induced by non-invasive brain stimulation, including transcranial direct current stimulation (tDCS). Nevertheless, the interaction between serotonin activation and neuroplasticity is not fully understood, particularly when considering dose-dependent effects. Read More

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Ultralow-power flexible transparent carbon nanotube synaptic transistors for emotional memory.

Nanoscale 2021 Jun 7. Epub 2021 Jun 7.

School of Electronic and Computer Engineering, Peking University, Shenzhen 518055, China.

Emulating the biological behavior of the human brain with artificial neuromorphic devices is essential for the future development of human-machine interactive systems, bionic sensing systems and intelligent robotic systems. In this paper, artificial flexible transparent carbon nanotube synaptic transistors (F-CNT-STs) with signal transmission and emotional learning functions are realized by adopting the poly(vinyl alcohol) (PVA)/SiO2 proton-conducting electrolyte. Synaptic functions of biological synapses including excitatory and inhibitory behaviors are successfully emulated in the F-CNT-STs. Read More

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In Situ Observation of Low-Power Nano-Synaptic Response in Graphene Oxide Using Conductive Atomic Force Microscopy.

Small 2021 Jun 3:e2101100. Epub 2021 Jun 3.

Physical Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia.

Multiple studies have reported the observation of electro-synaptic response in different metal/insulator/metal devices. However, most of them analyzed large (>1 µm ) devices that do not meet the integration density required by industry (10  devices/mm ). Some studies emploied a scanning tunneling microscope (STM) to explore nano-synaptic response in different materials, but in this setup there is a nanogap between the insulator and one of the metallic electrodes (i. Read More

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Clinical and Neurophysiological Effects of Botulinum Neurotoxin Type A in Chronic Migraine.

Toxins (Basel) 2021 May 29;13(6). Epub 2021 May 29.

Clinical Neurology Unit, Santa Maria della Misericordia University Hospital, 33100 Udine, Italy.

Chronic pain syndromes present a subversion of both functional and structural nociceptive networks. We used transcranial magnetic stimulation (TMS) to evaluate changes in cortical excitability and plasticity in patients with chronic migraine (CM) treated with botulinum neurotoxin type A (BoNT/A). We enrolled 11 patients with episodic migraine (EM) and 11 affected by CM. Read More

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Visual Attention and Motion Visibility Modulate Motor Resonance during Observation of Human Walking in Different Manners.

Brain Sci 2021 May 22;11(6). Epub 2021 May 22.

Department of Physical Therapy, Faculty of Rehabilitation, Kawasaki University of Medical Welfare, Kurashiki-City, Okayama 701-0193, Japan.

To advance our knowledge on the motor system during cyclic gait observation, we aimed to explore the effects of gaze fixation on corticospinal excitability evaluated by single-pulse transcranial magnetic stimulation (TMS). Fourteen healthy adult volunteers watched a video of a demonstrator walking on a treadmill under three different conditions: (1) observing the right lower limb, (2) observing the right ankle joint, and (3) observing the right lower limb on a video focused on the area below the knee. In each condition, motor-evoked potentials elicited by TMS in the tibialis anterior (TA) muscle were measured synchronously with the demonstrator's initial contact and toe-off points. Read More

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Serine/Threonine Phosphatases in LTP: Two B or Not to Be the Protein Synthesis Blocker-Induced Impairment of Early Phase.

Int J Mol Sci 2021 May 4;22(9). Epub 2021 May 4.

Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, 117485 Moscow, Russia.

Dephosphorylation of target proteins at serine/threonine residues is one of the most crucial mechanisms regulating their activity and, consequently, the cellular functions. The role of phosphatases in synaptic plasticity, especially in long-term depression or depotentiation, has been reported. We studied serine/threonine phosphatase activity during the protein synthesis blocker (PSB)-induced impairment of long-term potentiation (LTP). Read More

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Cardiorespiratory plasticity in humans following two patterns of acute intermittent hypoxia.

Exp Physiol 2021 May 28. Epub 2021 May 28.

Centre for Heart, Lung and Vascular Health, School of Health and Exercise Sciences, University of British Columbia, Kelowna, British Columbia, Canada.

New Findings: What is the central question of this study? Do cardiorespiratory experience-dependent effects (EDEs) differ between two different stimulus durations of acute isocapnic intermittent hypoxia (IHx; 5-min vs. 90-s cycles between hypoxia and normoxia)? What is the main finding and its importance? There was long-term facilitation in ventilation and blood pressure in both IHx protocols, but there was no evidence of progressive augmentation or post-hypoxia frequency decline. Not all EDEs described in animal models translate to acute isocapnic IHx responses in humans, and cardiorespiratory responses to 5-min versus 90-s on/off IHx protocols are largely similar. Read More

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Tyrosine phosphatase PTP1B impairs presynaptic NMDA receptor-mediated plasticity in a mouse model of Alzheimer's disease.

Neurobiol Dis 2021 May 24;156:105402. Epub 2021 May 24.

Neuroscience, Ottawa Hospital Research Institute, Ottawa, ON K1H8M5, Canada; University of Ottawa Brain and Mind Institute, Ottawa, ON K1H8M5, Canada; Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada; Department of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada. Electronic address:

Mutations in the beta-amyloid protein (APP) cause familial Alzheimer's disease. In hAPP-J20 mice expressing mutant APP, pharmacological inhibition or genetic ablation of the tyrosine phosphatase PTP1B prevents CA3 hippocampus neuron loss and cognitive decline. However, how targeting PTP1B affects the cellular mechanisms underlying these cognitive deficits remains unknown. Read More

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Characterization of the direct pathway in Dyt1 ΔGAG heterozygous knock-in mice and dopamine receptor 1-expressing-cell-specific Dyt1 conditional knockout mice.

Behav Brain Res 2021 May 24;411:113381. Epub 2021 May 24.

Norman Fixel Institute for Neurological Diseases, McKnight Brain Institute, and Department of Neurology, College of Medicine, University of Florida, Gainesville, FL, 32610-0236, USA. Electronic address:

DYT1 dystonia is a movement disorder mainly caused by a trinucleotide deletion (ΔGAG) in DYT1 (TOR1A), coding for torsinA. DYT1 dystonia patients show trends of decreased striatal ligand-binding activities to dopamine receptors 1 (D1R) and 2 (D2R). Dyt1 ΔGAG knock-in (KI) mice, which have the corresponding ΔGAG deletion, similarly exhibit reduced striatal D1R and D2R-binding activities and their expression levels. Read More

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Inactivation of Presenilin in inhibitory neurons results in decreased GABAergic responses and enhanced synaptic plasticity.

Mol Brain 2021 May 25;14(1):85. Epub 2021 May 25.

Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA.

Mutations in the Presenilin genes are the major genetic cause of Alzheimer's disease (AD). Presenilin (PS) is highly expressed in the hippocampus, which is particularly vulnerable in AD. Previous studies of PS function in the hippocampus, however, focused exclusively on excitatory neurons. Read More

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Effects of altered tau expression on dentate granule cell excitability in mice.

Exp Neurol 2021 May 21;343:113766. Epub 2021 May 21.

Department of Physiology, University of Kentucky College of Medicine, Lexington, KY 40536, USA; Department of Neuroscience, University of Kentucky College of Medicine, Lexington, KY 40536, USA. Electronic address:

Tauopathies, including Alzheimer's disease, are characterized by progressive accumulation of hyperphosphorylated and pathologic tau protein in association with onset of cognitive and behavioral impairment. Tau pathology is also associated with increased susceptibility to seizures and epilepsy, with tau mice showing seizure resistance in some epilepsy models. To better understand how tau pathology is related to neuronal excitability, we performed whole-cell patch-clamp electrophysiology in dentate gyrus granule cells of tau and human-tau expressing, htau mice. Read More

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Digital and analog functionality in monolayer AlOx-based memristors with various oxidizer sources.

Nanotechnology 2021 Jun 8;32(35). Epub 2021 Jun 8.

School of Information Science and Engineering (ISE), Shandong University, Qingdao, People's Republic of China.

Memristors with the outstanding advantages are beneficial for neuromorphic computing and next-generation storage. Realizing various resistive switching behaviors in monolayer memristors is essential for understanding the device physics and fabricating fully memristive devices. In this paper, a simple and feasible method was proposed to achieve the digital and analog resistive switching in Cu/AlOx/Ag memristors by using ozone and water precursors in atomic layer deposition. Read More

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Neuromodulation and neuroprotective effects of chlorogenic acids in excitatory synapses of mouse hippocampal slices.

Sci Rep 2021 May 18;11(1):10488. Epub 2021 May 18.

CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.

The increased healthspan afforded by coffee intake provides novel opportunities to identify new therapeutic strategies. Caffeine has been proposed to afford benefits through adenosine A receptors, which can control synaptic dysfunction underlying some brain disease. However, decaffeinated coffee and other main components of coffee such as chlorogenic acids, also attenuate brain dysfunction, although it is unknown if they control synaptic function. Read More

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Flexible Ta/TiO/TaO/Ru memristive synaptic devices on polyimide substrates.

Nanotechnology 2021 May 28;32(33). Epub 2021 May 28.

Tianjin Key Laboratory of Film Electronic & Communication Devices, School of Electrical and Electronic Engineering, Tianjin University of Technology, No. 391, Bin Shui Xi Dao Road, Xiqing District, Tianjin, 300384, People's Republic of China.

It is very urgent to build memristive synapses and even wearable devices to simulate the basic functions of biological synapses. The linear conductance modulation is the basis of analog memristor for neuromorphic computing. By optimizing the interface engineering wherein Ta/TiO/TaO/Ru was fabricated, all the memristor devices with different TiOthickness showed electroforming-free property. Read More

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Cholinergic and Noradrenergic Modulation of Corticothalamic Synaptic Input From Layer 6 to the Posteromedial Thalamic Nucleus in the Rat.

Front Neural Circuits 2021 26;15:624381. Epub 2021 Apr 26.

Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland.

Cholinergic and noradrenergic neuromodulation of the synaptic transmission from cortical layer 6 of the primary somatosensory cortex to neurons in the posteromedial thalamic nucleus (PoM) was studied using an slice preparation from young rats. Cholinergic agonist carbachol substantially decreased the amplitudes of consecutive excitatory postsynaptic potentials (EPSPs) evoked by a 20 Hz five pulse train. The decreased amplitude effect was counteracted by a parallel increase of synaptic frequency-dependent facilitation. Read More

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Short-Term High-Intensity Interval Exercise Promotes Motor Cortex Plasticity and Executive Function in Sedentary Females.

Front Hum Neurosci 2021 23;15:620958. Epub 2021 Apr 23.

Guangdong Provincial Key Laboratory of Sports and Health Promotion, Scientific Research Center, Guangzhou Sport University, Guangzhou, China.

Previous research has demonstrated that regular exercise modulates motor cortical plasticity and cognitive function, but the influence of short-term high-intensity interval training (HIIT) remains unclear. In the present study, the effect of short-term HIIT on neuroplasticity and executive function was assessed in 32 sedentary females. Half of the participants undertook 2 weeks of HIIT. Read More

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Nonvolatile resistive switching and synaptic characteristics of lead-free all-inorganic perovskite-based flexible memristive devices for neuromorphic systems.

Nanoscale 2021 May 4;13(19):8864-8874. Epub 2021 May 4.

Department of Physics, Cooch Behar Panchanan Barma University, West Bengal 736101, India.

Recently, several types of lead halide perovskites have been actively researched for resistive switching (RS) memory or artificial synaptic devices due to their current-voltage hysteresis along with the feasibility of fabrication, low-temperature processability and superior charge mobility. However, the toxicity and environmental pollution potential of lead halide perovskites severely restrict their large-scale commercial prospects. In the present work, the environmentally friendly and uniform CsSnCl perovskite films are introduced to act as an active layer in the flexible memristors. Read More

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PP1/PP2A phosphatase inhibition-induced metaplasticity in protein synthesis blocker-treated hippocampal slices: LTP and LTD, or There and Back again.

Biochem Biophys Res Commun 2021 Jun 23;558:64-70. Epub 2021 Apr 23.

Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, 117485, Butlerova 5A, Moscow, Russia.

Long-term potentiation (LTP) and long-term depression (LTD) are key forms of synaptic plasticity in the hippocampus. LTP and LTD are believed to underlie the processes occurring during learning and memory. Search of mechanisms responsible for switching from LTP to LTD and vice versa is an important fundamental task. Read More

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A synaptic memristor based on two-dimensional layered WSe nanosheets with short- and long-term plasticity.

Nanoscale 2021 Apr 29;13(13):6654-6660. Epub 2021 Mar 29.

College of Chemistry and Materials Science, Sichuan Normal University, Chengdu, 610066, China.

Neural synapses with diverse synaptic functions of short- and long-term plasticity are highly desired for developing complex neuromorphic systems. A memristor with its two terminals serving as pre- and post-neurons, respectively, can emulate two neuronal-based synaptic functions. In this work, multilayer two-dimensional (2D) layered WSe nanosheets are synthesized by a salt-assisted chemical vapor deposition (CVD) method. Read More

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Young DAPK1 knockout mice have altered presynaptic function.

J Neurophysiol 2021 May 21;125(5):1973-1981. Epub 2021 Apr 21.

Department of Pharmacology, University of Colorado Anschutz Medical Campus, Aurora, Colorado.

The death-associated protein kinase 1 (DAPK1) has recently been shown to have a physiological function in long-term depression (LTD) of glutamatergic synapses: acute inhibition of DAPK1 blocked the LTD that is normally seen at the hippocampal CA1 synapse in young mice, and a pharmacogenetic combination approach showed that this specifically required DAPK1-mediated suppression of postsynaptic Ca/calmodulin-dependent protein kinase II binding to the NMDA-type glutamate receptor (NMDAR) subunit GluN2B during LTD stimuli. Surprisingly, we found here that genetic deletion of DAPK1 (in DAPK1 mice) did not reduce LTD. Paired pulse facilitation experiments indicated a presynaptic compensation mechanism: in contrast to wild-type mice, LTD stimuli in DAPK1 mice decreased presynaptic release probability. Read More

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Long-term depression at hippocampal mossy fiber-CA3 synapses involves BDNF but is not mediated by p75NTR signaling.

Sci Rep 2021 Apr 20;11(1):8535. Epub 2021 Apr 20.

Institute of Physiology, Otto-von-Guericke University Magdeburg, 39120, Magdeburg, Germany.

BDNF plays a crucial role in the regulation of synaptic plasticity. It is synthesized as a precursor (proBDNF) that can be proteolytically cleaved to mature BDNF (mBDNF). Previous studies revealed a bidirectional mode of BDNF actions, where long-term potentiation (LTP) was mediated by mBDNF through tropomyosin related kinase (Trk) B receptors whereas long-term depression (LTD) depended on proBDNF/p75 neurotrophin receptor (p75NTR) signaling. Read More

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How the first years of motherhood impact the cardiac autonomic profile of female healthcare professionals: a study by heart rate variability analysis.

Sci Rep 2021 Apr 14;11(1):8161. Epub 2021 Apr 14.

Department of Biomedical Sciences for Health, University of Milan, Milan, Italy.

The conciliation between career and family is a relevant issue for working women, in particular during the first years of motherhood. Data about the state of the cardiac autonomic regulation in working women with preschoolers are lacking. Aim of this study was to compare the cardiac autonomic profile of female healthcare professionals with and without preschoolers via the analysis of the variability of the time distance between two consecutive R-wave peaks (RR) from standard 24-h Holter electrocardiogram (ECG). Read More

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Neural activity temporal pattern dictates long-range propagation targets.

Neuroimage 2021 Jul 7;235:118032. Epub 2021 Apr 7.

Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Pokfulam, Hong Kong SAR; Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam, Hong Kong SAR; School of Biomedical Sciences, LKS Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR. Electronic address:

Brain possesses a complex spatiotemporal architecture for efficient information processing and computing. However, it remains unknown how neural signal propagates to its intended targets brain-wide. Using optogenetics and functional MRI, we arbitrarily initiated various discrete neural activity pulse trains with different temporal patterns and revealed their distinct long-range propagation targets within the well-defined, topographically organized somatosensory thalamo-cortical circuit. Read More

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Altered acoustic startle, prepulse facilitation, and object recognition memory produced by corticosterone withdrawal in male rats.

Behav Brain Res 2021 Jun 6;408:113291. Epub 2021 Apr 6.

Division of Medical Sciences, University of Victoria, Victoria, BC, V8W 2Y2, Canada.

The symptoms of human depression often include cognitive deficits. However, cognition is not frequently included in the behavioral assessments conducted in preclinical models of depression. For example, it is well known that repeated corticosterone (CORT) injections in rodents produce depression-like behavior as measured by the forced swim test, sucrose preference test, and tail suspension test, but the cognitive impairments produced by repeated CORT have not been thoroughly examined. Read More

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Effects of rTMS on the brain: is there value in variability?

Cortex 2021 Jun 12;139:43-59. Epub 2021 Mar 12.

Innovation, IMPlementation and Clinical Translation (IIMPACT) in Health, University of South Australia, Adelaide, Australia.

The ability of repetitive transcranial magnetic stimulation (rTMS) to non-invasively induce neuroplasticity in the human cortex has opened exciting possibilities for its application in both basic and clinical research. Changes in the amplitude of motor evoked potentials (MEPs) elicited by single-pulse transcranial magnetic stimulation has so far provided a convenient model for exploring the neurophysiology of rTMS effects on the brain, influencing the ways in which these stimulation protocols have been applied therapeutically. However, a growing number of studies have reported large inter-individual variability in the mean MEP response to rTMS, raising legitimate questions about the usefulness of this model for guiding therapy. Read More

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Subcortical short-term plasticity elicited by deep brain stimulation.

Ann Clin Transl Neurol 2021 May 7;8(5):1010-1023. Epub 2021 Apr 7.

Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, Alabama, USA.

Objective: To investigate local short-term neuroplasticity elicited by subthalamic, thalamic, and pallidal deep brain stimulation (DBS) for movement disorders.

Methods: During DBS surgery, we delivered pairs of stimulus pulses with both circular and directional leads across 90 interstimulus intervals in 17 participants and recorded local field potentials from unused contacts on the implanted electrode array. We removed the stimulus artifact, validated the neural origin of the underlying signals, and examined short-term plasticity as a function of interstimulus interval and DBS target, using linear mixed effects models. Read More

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Emulating Artificial Synaptic Plasticity Characteristics from SiO-Based Conductive Bridge Memories with Pt Nanoparticles.

Micromachines (Basel) 2021 Mar 15;12(3). Epub 2021 Mar 15.

Department of Applied Physics, National Technical University of Athens, Iroon Polytechniou 9 Zografou, 15780 Athens, Greece.

The quick growth of information technology has necessitated the need for developing novel electronic devices capable of performing novel neuromorphic computations with low power consumption and a high degree of accuracy. In order to achieve this goal, it is of vital importance to devise artificial neural networks with inherent capabilities of emulating various synaptic properties that play a key role in the learning procedures. Along these lines, we report here the direct impact of a dense layer of Pt nanoparticles that plays the role of the bottom electrode, on the manifestation of the bipolar switching effect within SiO-based conductive bridge memories. Read More

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Short intracortical facilitation associates with motor-inhibitory control.

Behav Brain Res 2021 Jun 29;407:113266. Epub 2021 Mar 29.

Department of Rehabilitation Medicine, Guangzhou First People's Hospital, School of Medicine, South China University of Technology, Guangzhou, Guangdong, China. Electronic address:

The ability of motor-inhibitory control is important in daily life. Inhibitory control deficits are commonly observed in psychiatric conditions with enhanced impulsivity. The physiological mechanisms underlying the inhibitory control deficits are not well elucidated. Read More

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Optically stimulated synaptic transistor based on MoS/quantum dots mixed-dimensional heterostructure with gate-tunable plasticity.

Opt Lett 2021 Apr;46(7):1748-1751

In this Letter, we report an optically stimulated synaptic transistor based on / dots mixed-dimensional (MD) heterostructure, where the channel conductance shows a non-linear response to the optical stimuli. Paired-pulse facilitation is realized with the index above 200%, and the optical synaptic plasticity can be modulated by adjusting the amplitude, duration time, frequency, and power of light spikes. In addition, the long-term plasticity shows a gate-tunability, which can be attributed to the unique photoelectric coupling in / dots MD heterostructure. Read More

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Influence of Menstrual Cycle Phases on Neural Excitability in the Primary Somatosensory Cortex and Ankle Joint Position Sense.

Womens Health Rep (New Rochelle) 2020 16;1(1):167-178. Epub 2020 Jun 16.

Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Niigata, Japan.

Ankle sprain (AS) is one of the most common injuries among women engaged in competitive sports and recreational activities. Many studies have shown that several factors contributing to AS are influenced by the menstrual cycle. Despite the finding that abnormal joint position sense (JPS) is one of the major risk factors of AS, the alteration of the JPS throughout the menstrual cycle and its associated neural mechanisms remain unclear. Read More

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