Neural Trigger Research Articles

Neural Trigger of Speaking Skills in Autistic Children: An Intervention-Based Study

Autism is a pivotal language deficit among speakers all over the globe, and it is a restricting neural process that blocks the simultaneous exponential evolution of language usage; hence, it must be focused with some therapy stimuli. This study is an attempt to channel neural mechanisms underlying autistic children with controlled systemic interventions (CSI). Many previously conducted studies reported that speaking deficit in individuals at all levels reduces neural processing that blocks smooth speaking, and it is due to anatomical and neurophysiological underpinning factors. In this context of autism, anatomical factors are genetic, but neurophysiological can be reversed via controlled systemic intervention (CSI) that is used in this study. For providing neuropsychological reverse, many interventions have been constructed, but this study is only taking Repeat After Me (RAM) as an intervention using computer-assisted. For achieving neural triggers, this study adopts an experimental methodology. Autistic children were recruited via snowball sampling technique, and they are 48 (mean age=2-6 years, boys=28, girls=20). On their willingness to participate in the study, they were divided into two groups: control and experimental. The interventions were provided within six weeks, and the children were assessed via WSSPI-III before the interventions and after the interventions. The overall results of the study predict that in post-assessments, there is a significant satisfactory result. The study implies that 'RAM' should be adopted by parents in home settings and therapists in institutional settings to expedite neural processing that will help boost children's speaking skills with smooth fluency.

Neural-network-based level-1 trigger upgrade for the SuperCDMS experiment at SNOLAB

The extended physics program of the SuperCDMS SNOLAB dark matter search experiment aims to maximize the sensitivity to low-mass dark matter. To realize this, an upgrade of the existing level-1 trigger of the data acquisition system is proposed by making use of a recurrent neural network to be implemented on the trigger FPGA. This provides an improved amplitude estimator and signal-noise discriminator based on the combined information of filtered traces from individual detector channels. The architecture and configuration of this neural trigger are discussed in this article, and the improvements in key performance indicators such as the efficiency, resolution, and noise rate are quantified based on signal simulations and noise data. Based on the findings in this proof of concept, the trigger threshold is expected to be lowered by ∼ 22%.

Neuroendocrine control of gonadotropin-releasing hormone: Pulsatile and surge modes of secretion.

The concept that different systems control episodic and surge secretion of gonadotropin-releasing hormone (GnRH) was well established by the time that GnRH was identified and formed the framework for studies of the physiological roles of GnRH, and later kisspeptin. Here, we focus on recent studies identifying the neural mechanisms underlying these two modes of secretion, with an emphasis on their core components. There is now compelling data that kisspeptin neurons in the arcuate nucleus that also contain neurokinin B (NKB) and dynorphin (i.e., KNDy cells) and their projections to GnRH dendrons constitute the GnRH pulse generator in mice and rats. There is also strong evidence for a similar role for KNDy neurons in sheep and goats, and weaker data in monkeys and humans. However, whether KNDy neurons act on GnRH dendrons and/or GnRH soma and dendrites that are found in the mediobasal hypothalamus (MBH) of these species remains unclear. The core components of the GnRH/luteinising hormone surge consist of an endocrine signal that initiates the process and a neural trigger that drives GnRH secretion during the surge. In all spontaneous ovulators, the core endocrine signal is a rise in estradiol secretion from the maturing follicle(s), with the site of estrogen positive feedback being the rostral periventricular kisspeptin neurons in rodents and neurons in the MBH of sheep and primates. There is considerable species variations in the neural trigger, with three major classes. First, in reflex ovulators, this trigger is initiated by coitus and carried to the hypothalamus by neural or vascular pathways. Second, in rodents, there is a time of day signal that originates in the suprachiasmatic nucleus and activates rostral periventricular kisspeptin neurons and GnRH soma and dendrites. Finally, in sheep nitric oxide-producing neurons in the ventromedial nucleus, KNDy neurons and rostral kisspeptin neurons all appear to participate in driving GnRH release during the surge.

Clinical Application of Neurally Adjusted Ventilatory Assist in Neonates with Respiratory Distress: A Systematic Review

Context: Neurally adjusted ventilatory assist (NAVA) is a novel mode of ventilation that coordinates the mechanical ventilator and the patient via electrical impulses of the diaphragm. Using these impulses as neural triggers, the patient’s respiration synchronizes with the ventilator. Ventilation with NAVA has successfully been performed in adults with various lung diseases but the application of NAVA in neonates is a novel issue. Objectives: The aim of this review study was to emphasize the NAVA as a new way of neonatal ventilatory support and the importance of ventilator-neonate synchrony in neonatal intensive care units. Study Selection: Several studies have evaluated NAVA in the neonatal period but we described here the cardinal studies. Therefore, we included studies performing NAVA in the neonatal and pediatric population. Results: The review of 10 studies showed that asynchrony was less frequent when using NAVA than when using the pneumatic modes of ventilation. Most of the studies observed a reduction in peak inspiratory pressure (PIP) and FIO2 with NAVA. A reduction in mean airway pressure and work of breathing and an improvement in gas exchange were also observed in some of the studies. Conclusions: We concluded that according to recent studies, the NAVA should be administered in neonates for better synchronization with ventilator and improving the gas exchange and outcomes.

Future Noninvasive Ventilation Strategies in Neonates

The use of noninvasive ventilation (NIV) has increased over the past decade. Most NICUs use various forms of noninvasive positive pressure ventilation that is influenced by leaks at the interface. This limits the effectiveness of using a flow trigger for synchronous delivery of each breath and the resultant asynchrony contributes to the failure of NIV. Two novel approaches to NIV are now available. Noninvasive neurally adjusted ventilatory assist uses a neural trigger to detect the electrical activation of the diaphragm. Each breath is then proportionally assisted based on the onset, strength, and duration of this electrical signal. It is therefore leak-independent and overcomes the challenges of flow-triggered ventilation. High-frequency nasal ventilation is an extension of bubble continuous positive airway pressure and delivers small tidal volumes at high frequencies that can be adjusted to provide appropriate noninvasive support. The functionality of both these modalities will be discussed, including the clinical evidence available to support their use with NIV.

The Neuro-Z-Vertex Trigger of the Belle II Experiment

A neural network z vertex trigger is planned for the upcoming Belle II detector at the SuperKEKB collider. This neural algorithm is based on a single track 3D parameter estimation using only hit and drift time information from the central drift chamber. Due to the high luminosity ( L = 8 × 10 35 cm −2 s −1 ) Belle II will have to face high levels of beam induced background, making a z vertex reconstruction at the first level trigger mandatory. Using the neural z vertex algorithm, the requirements of the standard track trigger can be strongly relaxed. By this, the trigger efficiencies, especially for low multiplicity events, e.g. τ pair production, can be significantly increased.This contribution presents the foreseen neural network trigger setup and the preceding 2D track finder. Special focus is put on the proposal and evaluation of a possible 3D upgrade of the 2D track finder. Additionally, details are given on a dedicated setup for the upcoming cosmic ray test.

Gut sweet taste receptors and their role in metabolism.

Obesity is caused by an imbalance between food intake and energy expenditure. In recent decades the gastrointestinal tract has received growing attention as a control parameter for the regulation of appetite and food intake, however regulatory circuits and their interactions are complex. The basic understanding on the role of the gut starts with the notion 'we are what we eat'. Food enters the gastrointestinal tract, which then triggers specific mechanisms or a sensing machinery that respond to specific components of food. Enteroendocrine cells in the small intestine are the anatomical basis for the sensing machinery, which act as neural triggers or as intestinal satiation peptide-secreting cells. These cells express chemosensory receptors that respond to luminal stimuli. The understanding of each gastrointestinal mechanism that might be involved in the process of eating provides a basis for the assessment of the potential of the gastrointestinal tract in the fight against obesity. This review discusses the function of the gut sweet taste receptor T1R2/T1R3 in sensing sweet compounds, as well as its role in gastrointestinal peptide secretion and glucose metabolism.

Retrospective review of utilisation and outcomes of diaphragmatic EMG monitoring and neurally adjusted ventilatory assist in a central London teaching hospital over a 3-year period

The theoretical advantages of monitoring the electrical activity of the diaphragm (EAdi) and neural triggering of support breaths (NAVA-Maquet) have not yet been shown to translate into significant clinical benefit [1]. Here we assess the effect of EAdi monitoring, in patients at risk of prolonged weaning, on outcomes.

The distributed somatotopy of tremor: A window into the motor system

The posterior ventrolateral thalamus (VLp) plays a crucial role in Parkinson's tremor and in essential tremor: deep brain stimulation (DBS) of the VLp effectively diminishes both tremor types. Previous research has shown tremor oscillations in the VLp, but the spatial extent and somatotopy of these oscillations remained unclear. In this issue of Experimental Neurology, Pedrosa and colleagues measured neuro-muscular coherence at multiple sites in the VLp of patients with essential tremor and Parkinson's disease using implanted DBS electrodes (Pedrosa et al., 2012). They found multiple tremor clusters within the VLp, with spatially distinct tremor clusters for antagonistic muscles, and in many patients also multiple distinct tremor clusters for a single muscle. Interestingly, this group previously showed similar effects for the STN in tremulous Parkinson's disease (Reck et al., 2009, 2010). Together, these studies suggest that the distribution of tremor clusters is a general organizational principle of tremor, being present in two different tremor pathologies, and in two different nodes of the motor system. The presence of multiple tremor clusters also fits with the distributed somatotopy of the healthy motor system. Therefore, a further conclusion of this study could be that tremor is caused by aberrant synchronization within an otherwise healthy network, brought about by different pathophysiological neural triggers.

Use of neural trigger during neurally adjusted ventilatory assist in a patient with a large broncho-pleural fistula and air leakage

Use of neural trigger during neurally adjusted ventilatory assist in a patient with a large broncho-pleural fistula and air leakage

Neurally triggered breaths reduce trigger delay and improve ventilator response times in ventilated infants with bronchiolitis

Neurally adjusted ventilatory assist (NAVA) is a mode of ventilation designed to improve patient-ventilator interaction by interpreting a neural signal from the diaphragm to trigger a supported breath. We hypothesized that neurally triggered breaths would reduce trigger delay, ventilator response times, and work of breathing in pediatric patients with bronchiolitis. Subjects with a clinical diagnosis of bronchiolitis were studied in volume support (pneumatic trigger) and NAVA (pneumatic and neural trigger) in a crossover design. Airway flow and pressure waveforms were obtained with a pneumotachograph and computerized digital recorder and were recorded for 120 s for each experiment. Neurally triggered breaths had less trigger delay (ms) (40 ± 27 vs. 98 ± 34; p < 0.001) and reduced ventilator response times (ms) (15 ± 7 vs. 36 ± 25; p < 0.001) compared with pneumatically triggered breaths. Neurally triggered breaths had reduced pressure-time product (PTP) area A (cmH(2)O * s), the area of the pressure curve from initiation of breath to start of ventilator pressurization (0.013 ± 0.010; p < 0.001), and reduced PTP area B (cmH(2)O * s), the area of the pressure curve from start of ventilator pressurization to return of baseline pressure (0.008 ± 0.006 vs. 0.023 ± 0.009; p = 0.003). Reduced PTP may indicate decreased work of breathing. Neurally triggered breaths reduce trigger delay, improve ventilator response times, and may decrease work of breathing in children with bronchiolitis. Further analysis is required to determine if neurally triggered breaths will improve patient-ventilator synchrony.

Neurally adjusted ventilatory assist in patients recovering spontaneous breathing after acute respiratory distress syndrome: Physiological evaluation*

Pressure-support ventilation is widely used during the weaning phase in patients with acute respiratory distress syndrome. The pressure-support level is adjusted to prevent ventilator-induced lung injury while limiting the patient's work of breathing. Neurally adjusted ventilatory assist is an assist mode that applies a positive pressure proportional to the integral of the electrical activity of the diaphragm. The objective was to assess the physiologic response to varying pressure-support ventilation and neurally adjusted ventilatory assist levels in selected acute respiratory distress syndrome patients and to evaluate the effect of neural triggering. We prospectively assessed 11 consecutive patients with acute respiratory distress syndrome attributable to pulmonary diseases. Pressure-support ventilation and neurally adjusted ventilatory assist were used in random order. Neurally adjusted ventilatory assist was used with a low electrical activity of the diaphragm trigger (neurally adjusted ventilatory assist-electrical activity of the diaphragm) and with a high electrical activity of the diaphragm trigger that led to rescue triggering by inspiratory flow (neurally adjusted ventilatory assist-inspiratory flow). With each ventilation modality, four levels of assistance (100%, 120%, 140%, and 160%) were used in random order. Statistical analysis was performed using analysis of variance for repeated measurements and mixed models. Contrary to pressure-support ventilation, neurally adjusted ventilatory assist-electrical activity of the diaphragm and neurally adjusted ventilatory assist-inspiratory flow were associated with stable tidal volume levels despite increasing assistance. For the asynchrony index, an interaction was present between ventilation mode and assist level (p = .0076) because asynchrony index increased significantly with the pressure-support ventilation level (p = .004), but not with the neurally adjusted ventilatory assist-electrical activity of the diaphragm or neurally adjusted ventilatory assist-inspiratory flow level. The lowest asynchrony index was obtained with neurally adjusted ventilatory assist-electrical activity of the diaphragm. Compared to pressure-support ventilation, neurally adjusted ventilatory assist in acute respiratory distress syndrome patients holds promise for limiting the risk of overassistance, preventing patient-ventilator asynchrony, and improving overall patient-ventilator interactions. Neural triggering (neurally adjusted ventilatory assist-electrical activity of the diaphragm) considerably decreased patient-ventilator asynchrony.

Neurally adjusted ventilatory assist in children: An observational study

To assess patient safety and to evaluate operator acceptance to the technology of neurally adjusted ventilatory assist. A within-patient crossover study. A ten-bed tertiary care university hospital pediatric intensive care unit. A total of 21 mechanically ventilated infants and children aged 2 days to 15 yrs suffering from a variety of disorders. The majority of patients were treated after cardiac surgery. In patients with pressure-support ventilation, a nasogastric neurally adjusted ventilatory assist catheter was positioned to detect the diaphragm electrical impulse. Initiation and termination of ventilatory support for each breath could then be regulated either through conventional volume or pressure changes or through changes in the detected diaphragm electrical impulse signal. Ventilation was started as pressure-support ventilation for 30 mins, changed to neurally adjusted ventilatory assist for 30 mins, switched back to pressure-support ventilation for 30 mins and then neurally adjusted ventilatory assist until an end-point criterion was reached. There were no serious adverse events during the study and all patients were circulatory and respiratory stable. The neurally adjusted ventilatory assist catheter was easy to place. The treatment time with neurally adjusted ventilatory assist ranged from 1 to 8 hrs (median = 2.5 hrs). During neurally adjusted ventilatory assist, the peak airway pressures decreased as compared with pressure-support mode but the mean airway pressures were not significantly changed.The respiratory rates increased during neurally adjusted ventilatory assist. The neural trigger on was first in 68% (median) whereas the neural trigger off was first in 88% (median) as compared with the pneumatic trigger on and off. Eight of the patients could be extubated in close connection to the termination of the neurally adjusted ventilatory assist treatment. We feel that neurally adjusted ventilatory assist would be safe and potentially efficacious to ventilate infants and children. It has the potential for improved patient-ventilator synchrony, decreasing airway pressures, and it might lead to earlier extubation.

A central role for the periphery in the rapid action of cocaine on brain neurons:focus on “Rapid EEG desynchronization and EMG activation induced by intravenous cocaine in freely moving rats: a peripheral, nondopamine neural triggering”

back in the day when research in neuropharmacology was done almost exclusively on peripheral tissue, limited technology prevented sophisticated assessments of drug-induced changes in brain function. As technology improved, so did the scope of investigation, and researchers today study the brain

Rapid EEG desynchronization and EMG activation induced by intravenous cocaine in freely moving rats: a peripheral, nondopamine neural triggering

Many important physiological, behavioral, and psychoemotional effects of intravenous (IV) cocaine (COC) are too fast and transient compared with pharmacokinetic predictions, suggesting a possible involvement of peripheral neural mechanisms in their triggering. In the present study, we examined changes in cortical electroencephalogram (EEG) and neck electromyogram (EMG) induced in freely moving rats by IV COC administration at low, reinforcing doses (0.25-1.0 mg/kg) and compared them with those induced by an auditory stimulus and IV COC methiodide, which cannot cross the blood-brain barrier. We found that COC induces rapid, strong, and prolonged EEG desynchronization, associated with decrease in alpha and increase in beta and gamma activities, and EMG activation and that both begin within 2-6 s following the start of a 10-s injection; immediate components of this effect were dose independent. The rapid COC-induced changes in EEG and EMG resembled those induced by an auditory stimulus; the latter effects had shorter onset latencies and durations and were fully blocked during urethane anesthesia. Although urethane anesthesia completely blocked COC-induced EMG activation and rapid components of EEG response, COC still induced EEG desynchronization that was much weaker, greatly delayed (approximately 60 s), and associated with tonic decreases in delta and increases in alpha, beta, and gamma activities. Surprisingly, IV saline delivered during slow-wave sleep (but not quite wakefulness) also induced a transient EEG desynchronization but without changes in EMG activity; these effects were also fully blocked during anesthesia. Peripherally acting COC methiodide fully mimicked rapid EEG and EMG effects of regular COC, but the effects at an equimolar dose were less prolonged than those with regular COC. These data suggest that in awake animals IV COC, like somato-sensory stimuli, induces cortical activation and a subsequent motor response via its action on peripheral neural elements and involving rapid neural transmission. By providing a rapid neural signal and triggering transient neural activation, such an action might play a crucial role in the sensory effects of COC, thus contributing to the learning and development of drug-taking behavior.

Innovations in Mechanical Ventilation

New features of mechanical ventilators are frequently introduced, including new modes, monitoring techniques, and triggering techniques. But new rarely translates into any measureable improvement in outcome. We describe 4 new techniques and attempt to define what is a new invention versus what is innovative-a technique that significantly improves a measurable variable. We describe and review the literature on automated weaning, automated measurement of functional residual capacity, neural triggering, and novel displays of respiratory mechanics.

The neural response to facial attractiveness.

What are the neural correlates of attractiveness? Using functional MRI (fMRI), the authors addressed this question in the specific context of the apprehension of faces. When subjects judged facial beauty explicitly, neural activity in a widely distributed network involving the ventral occipital, anterior insular, dorsal posterior parietal, inferior dorsolateral, and medial prefrontal cortices correlated parametrically with the degree of facial attractiveness. When subjects were not attending explicitly to attractiveness, but rather were judging facial identity, the ventral occipital region remained responsive to facial beauty. The authors propose that this region, which includes the fusiform face area (FFA), the lateral occipital cortex (LOC), and medially adjacent regions, is activated automatically by beauty and may serve as a neural trigger for pervasive effects of attractiveness in social interactions.

Subject-ventilator synchrony during neural versus pneumatically triggered non-invasive helmet ventilation.

ObjectivePatient–ventilator synchrony during non-invasive pressure support ventilation with the helmet device is often compromised when conventional pneumatic triggering and cycling-off were used. A possible solution to this shortcoming is to replace the pneumatic triggering with neural triggering and cycling-off—using the diaphragm electrical activity (EAdi). This signal is insensitive to leaks and to the compliance of the ventilator circuit.DesignRandomized, single-blinded, experimental study.SettingUniversity Hospital.Participants and subjectsSeven healthy human volunteers.InterventionsPneumatic triggering and cycling-off were compared to neural triggering and cycling-off during NIV delivered with the helmet.Measurements and resultsTriggering and cycling-off delays, wasted efforts, and breathing comfort were determined during restricted breathing efforts (<20% of voluntary maximum EAdi) with various combinations of pressure support (PSV) (5, 10, 20 cm H2O) and respiratory rates (10, 20, 30 breath/min). During pneumatic triggering and cycling-off, the subject–ventilator synchrony was progressively more impaired with increasing respiratory rate and levels of PSV (p < 0.001). During neural triggering and cycling-off, effect of increasing respiratory rate and levels of PSV on subject–ventilator synchrony was minimal. Breathing comfort was higher during neural triggering than during pneumatic triggering (p < 0.001).ConclusionsThe present study demonstrates in healthy subjects that subject–ventilator synchrony, trigger effort, and breathing comfort with a helmet interface are considerably less impaired during increasing levels of PSV and respiratory rates with neural triggering and cycling-off, compared to conventional pneumatic triggering and cycling-off.Electronic supplementary materialThe online version of this article (doi:10.1007/s00134-008-1163-z) contains supplementary material, which is available to authorized users.

Neural trigger and cycling off during helmet pressure support ventilation: the epitome of the perfect patient ventilator interaction?

Neural trigger and cycling off during helmet pressure support ventilation: the epitome of the perfect patient ventilator interaction?

Urge-to-Cough: What Can It Teach Us About Cough?

The Urge-to-Cough is a component of the brain motivation system that mediates cognitive responses to cough stimuli. There are six stages to the cough motivation-to-action system: (1) stimulus, the trigger for the neural event; (2) urge, the physical need to respond to the stimulus; (3) desire, translation of urge into a central neural targeted goal; (4) action, physical response that satisfies the urge-desire; (5) evidence, feedback to the neural system on the action; (6) reward, sensory system that determines if the urge was satisfied. Urge-to-Cough is related to three fundamental types of cough: (1) reflex cough, (2) voluntary cough, and (3) behavioral cough. Urge-to-Cough with reflex cough can be studied by measuring the sensations elicited by a cough stimulus. Neural processes with voluntary cough can be studied using magnitude production cognitive psychometric methods. Results of these studies have shown if the subjects can reliably estimate their Urge-to-Cough, the urge increases with increasing cough stimulus, there is a correlation between the Urge-to-Cough and cough intensity, there is a threshold for eliciting the sensation of the urge that precedes the motor cough behavior, subjects can voluntarily produce coughs of varying magnitudes, the motor cough pattern is directly related to the perceived magnitude of a cough, volitional triggers of a cough are directly related to the reflex cough pattern, and neural triggers of cough initiate a stereotypic motor output. Understanding the Urge-to-Cough motivation-to-action system opens new strategies for research on central neural cough mechanisms.