4hz

This study aims to investigate the impact of gamma-radiation on the cerebral- and cerebellar-cortex of rat's brain. Animals were whole-body exposed to 3Gy, every 3 days, up to 9Gy, and sacrificed 1hour, 1, 3, 7 & 10 days post the last radiation-dose. Irradiation triggers oxidative stress. Superoxide dismutase, catalase, glutathione reductase decreased, malondialdehyde and protein carbonyl increased from the 1st hour till the 10th day in both tissues. Glutathione peroxidase and glutathione decreased from the 1st hour in the cerebral-cortex, and 3rd day in the cerebellar-cortex...

Background: Acute increases in exercise-induced oxygen uptake (V̇O2 ) is crucial for aerobic training adaptations and depends on how much muscle mass is involved during exercising. Thus, handcycling is per se limited for higher maximal oxygen uptakes (V̇O2 max) due to restricted muscle involvement. Handcycling with additional and simultaneous application of low-frequency electromyostimulation (EMS) to the lower extremities might be a promising stimulus to improve aerobic capacity in disabled and rehabilitative populations...

Activity dependent stimulation (ADS) is a closed loop stimulation technique whose neurophysiological effects have not been deeply investigated. Here we explored how Local field Potentials (LFP) are impacted by a focal ischemic lesion and, subsequently, by ADS treatment. Intracortical microelectrode arrays were implanted in the rostral forelimb area (RFA) and in the primary somatosensory area (S1) of anaesthetized rats. An ischemic injury was induced in the caudal forelimb area through microinjections of Endothelin-1...

OBJECTIVE: To explain the 0.2-2Hz oscillation in human balance. MOTIVATION: Oscillation (0.2-2 Hz) in the control signal (ankle moment) is sustained independently of external disturbances and exaggerated in Parkinsons disease. Does resonance or limit cycles in the neurophysiological feedback loop cause this oscillation We investigate two linear (non-predictive, predictive) and one non-linear (intermittent-predictive) control model (NPC, PC, IPC). METHODS: Fourteen healthy participants, strapped to an actuated single segment robot with dynamics of upright standing, used natural haptic-visual feedback and myoelectric control signals from lower leg muscles to maintain balance...

Cardiac injury, such as myocardial infarction (MI), leads to neurohormonal activation and autonomic remodeling, resulting in reflexive sympathoexcitation and parasympathetic dysfunction, which further contribute to progression of disease. The purpose of this study was to determine whether chronic cervical vagal nerve stimulation (VNS) influences MI-associated changes in cardiac sympathetic function. Yucatan minipigs were divided into control (n=6), chronic MI (n=7), and chronic MI + chronic VNS (n=8) groups...

Previous evidence showed abnormal parietal sources of resting-state electroencephalographic (EEG) delta (< 4Hz) and alpha (8-12Hz) rhythms in treatment-Naïve HIV (Naïve HIV) subjects, as cortical neural synchronization markers in quiet wakefulness. Here, we tested the hypothesis that these local abnormalities may be related to functional cortical dysconnectivity as an oscillatory brain network disorder. The present EEG database regarded 128 Naïve HIV and 60 Healthy subjects. The eLORETA freeware estimated lagged linear EEG source connectivity (LLC)...

We present a stimulate and record paradigm to examine the behavior of multiple neuronal networks with controlled topology in vitro. Our approach enabled us to electrically induce and record neuronal activity from 60 independent networks in parallel over multiple weeks. We investigated the network performance of neuronal networks of primary hippocampal neurons until 29 days in vitro. We introduced a systematic stimulate and record protocol during which well-defined 4-node neural networks were stimulated electrically 4 times per second (4Hz) and their response was recorded over many days...

Attention-deficit hyperactivity disorder (ADHD) in adults is understudied, especially regarding neural mechanisms such as oscillatory control of attention sampling. We report an EEG study of such cortical mechanisms, in ADHD-diagnosed adults during administration of TOVA (Test of Variables of Attention), a gold-standard continuous performance test for ADHD that measures the ability to sustain attention and inhibit impulsivity.We recorded 53 adults (28f, 25m, aged 18-60), and 18 matched healthy controls, using 128-channel EEG...

Suicide is a global health problem, and early and accurate identification of suicide attempt individuals has very important clinical significance. Thus the exploration of neurobiological mechanisms underlying suicidal behavior is crucial for systematically preventing suicide. However, the neurophysiological biomarkers for identifying affective disorders with suicidal attempt are remain unknown. Here, we recruited 28 patients with mental disorders from Tianjin Anding Hospital, and the subjects were divided into suicide attempt group (SA=14) and non suicide attempt group (NSA=14) according to whether they had attempted suicide...

Recent evidence suggests that visual attention alternately samples two behaviorally relevant objects at approximately 4Hz, rhythmically shifting between the objects. Whether similar attentional rhythms exist in other sensory modalities, however, is not yet clear. We therefore adapted and extended an established paradigm to investigate visual and potential auditory attentional rhythms, as well as possible interactions, on both a behavioral (detection performance, N=33) and a neural level (EEG, N=18). The results during unimodal attention demonstrate that both visual- and auditory-target detection fluctuate at frequencies of approximately 4-8Hz, confirming that attentional rhythms are not specific to visual processing...

BACKGROUND: Strong electric shocks are the gold-standard for ventricular defibrillation, but are associated with pain and tissue damage. We hypothesize that targeting the excitable gap (EG) of reentry with low-energy surface stimulation is a less damaging and painless alternative for ventricular defibrillation. OBJECTIVE: Determine the conditions under which low-energy surface stimulation defibrillates large mammalian ventricles. METHODS: Low-energy surface stimulation was delivered with five 7 cm long electrodes placed 1-2 cm apart on the endocardial and epicardial surfaces of perfused pig left ventricle (LV)...

BACKGROUND: To evaluate whether interictal epileptiform discharges (IEDs) that are not visible on the scalp are associated with changes in frequency spectrum on scalp EEG. METHODS: We recorded simultaneous scalp high-density EEG and intracranial EEG recordings in 9 patients undergoing presurgical invasive recordings for pharmaco-resistant temporal lobe epilepsy. We selected epochs with hippocampal IED visible on intracranial EEG (ic-IED) but not on scalp EEG, as well as control epochs without intracranial EEG IED...

The search for alternative antimicrobial strategies capable of avoiding resistance mechanisms in bacteria are highly needed due to the alarming emergence of antimicrobial resistance. The application of physical stimuli as a mean of sensitizing bacteria for the action of antimicrobials on otherwise resistant bacteria or by allowing the action of low quantity of antimicrobials may be seen as a breakthrough for such purpose. This work proposes the development of antibacterial nanocomposites using the synergy between the electrically active microenvironments, created by a piezoelectric polymer (poly(vinylidene fluoride-co-trifluoroethylene) (PVDF-TrFE)), with green-synthesized silver nanoparticles (AgNPs)...

Tinnitus is a heterogeneous phenomenon indexed by various EEG oscillatory profiles. Applying neurofeedback (NFB) with the aim of changing these oscillatory patterns not only provides help for those who suffer from the phantom percept, but a promising foundation from which to probe influential factors. The reliable attribution of influential factors that potentially predict oscillatory changes during the course of NFB training may lead to the identification of subgroups of individuals that are more or less responsive to NFB training...

The fatigue-induced neuromuscular mechanism remains to be fully elucidated. So far, the macroscopic mechanism using global surface electromyogram (sEMG) has been widely investigated. However, the microscopic mechanism using high-level neural information based on motor unit (MU) spike train from the spinal cord lacks attention, especially for the conditions under dynamic contraction task. The synchronization of the MU spike train is generally assumed to be an excellent indicator to represent the activities of spinal nerves...

Moderate to severe pain is often treated with opioids, but central mechanisms underlying opioid analgesia are poorly understood. Findings thus far have been contradictory and none could infer opioid specific effects. This placebo-controlled, randomized, 2-way cross-over, double-blinded study aimed to explore opioid specific effects on central processing of external stimuli. Twenty healthy male volunteers were included and 3 sets of assessments were done at each of the 2 visits: 1) baseline, 2) during continuous morphine or placebo intravenous infusion and 3) during simultaneous morphine + naloxone or placebo infusion...

BACKGROUND AND OBJECTIVE: Eyestrain has been increasingly severe in our lives and works as the progress of computers and smartphones. Evaluating eyestrain helps to prevent and relieve eyestrain. Our study aimed to evaluate eyestrain by analyzing vertical electrooculogram (VEOG). METHODS: 21 young subjects were asked to watch a video on the computer for a totally 120 minutes each, during which the VEOG signal was acquired using only three electrodes, and the questionnaire was answered every 30 minutes...

Conceptual knowledge allows the categorisation of items according to their meaning beyond their physical similarities. This ability to respond to different stimuli (e.g., a leek, a cabbage, etc.) based on similar semantic representations (e.g., belonging to the vegetable category) is particularly important for language processing, because word meaning and the stimulus form are unrelated. The neural basis of this core human ability is debated and is complicated by the strong reliance of most neural measures on explicit tasks, involving many non-semantic processes...

BACKGROUND: Portosystemic shunts in Hereditary Haemorrhagic Telangiectasia (HHT) are often overlooked by conventional imaging although they could reduce hepatic clearance of gut-derived toxins. AIMS: To evaluate, the presence of subclinical neurological alterations (SNAs), that we named "minimal portosystemic encephalopathy" (mPSE) in HHT patients without advanced liver disease (ALD). METHODS: In this cross sectional study, consecutive HHT outpatients were firstly screened by critical flicker frequency (CFF) test (abnormal ≤39Hz), and the simplified animal naming test (S-ANT1 ) (abnormal <15) was used to confirm the diagnosis of mPSE...

BACKGROUND: Temporal dynamics may importantly modulate sensory perception, including taste. For example, enhanced perceived taste intensity is often observed when tastant concentration is fluctuating in pulses. The perceived intensity is higher than that of the solutions with a same averaged, but constant concentrations. Meanwhile, taste intensity often decreases with increase of tastant viscosity, despite no changes to the stimuli concentration. The mechanisms to these phenomena are not well understood, in part due to the complicated transport process of tastant through papillae, taste pores, etc...