scholarly journals Brain and behavioral effects of swallowing carbonated water on the human pharyngeal motor system

2016 ◽  
Vol 120 (4) ◽  
pp. 408-415 ◽  
Author(s):  
Omsaad Elshukri ◽  
Emilia Michou ◽  
Hannah Mentz ◽  
Shaheen Hamdy
Keyword(s):  
Citric Acid ◽  
Time Window ◽  
Single Pulse ◽  
Potential Benefits ◽  
Underlying Mechanisms ◽  
Dysphagic Patients ◽  
Liquid Bolus ◽  
Carbonated Liquids ◽  
Predetermined Time ◽  
Stimulation Of

Chemical stimulation of the swallowing network with carbonation and citric acid has been investigated, showing potential benefits on swallowing of dysphagic patients. Despite this, the underlying mechanisms for these effects are not fully understood. Here we investigated the effects of 5 ml liquid bolus swallows of carbonated, citric acid, and still water on a swallowing reaction-time tasks paradigm in 16 healthy adults (8 male, mean age 33 ± 3.7 yr, protocol 1). We then investigated the net effects of “sensory bolus interventions” (40 repeated swallows every 15 s) of the three different liquid boluses on corticobulbar excitability, as examined with single-pulse transcranial magnetic stimulation (TMS) in 16 participants (8 female, mean age 33 ± 3.7 yr, protocol 2). The findings showed that a larger number of correctly timed swallows (within a predetermined time window) was accomplished mainly with carbonated liquids ( z = −2.04, P = 0.04 vs. still water, protocol 1). Both carbonated and citric acid liquid interventions with 40 swallows increased corticobulbar excitability of the stronger pharyngeal projection, suggesting a similar modulatory pathway for the effects on swallowing. However, carbonation showed superiority ( P = 0.04, F = 4.75, 2-way ANOVA), with the changes lasting up to 60 min following the intervention. These results hold significance for future further and in-depth physiological investigations of the differences between different stimuli on swallowing neural network.

Using ionizing radiation for improving the development and yield of agricultural crops.

2021 ◽  
pp. 424-432
Author(s):  
Stanislav Geras'kin ◽  
Roman Churyukin ◽  
Polina Volkova ◽  
Sofiya Bitarishvili
Keyword(s):  
Plant Growth ◽  
Gamma Irradiation ◽  
Crop Production ◽  
Radiation Effects ◽  
Dose Range ◽  
Growing Season ◽  
Potential Benefits ◽  
Underlying Mechanisms ◽  
Stimulation Of

Abstract The response of barley seedlings was studied after gamma irradiation of seeds with doses in the range of 2-50 Gy. It was shown that stimulation of plant growth occurred in the dose range of 16-20 Gy. The influences of the dose rate, the quality of seeds and their moisture on the manifestation of radiation effects were investigated. We studied, under controlled conditions, the activities of metabolic and antioxidant enzymes and observed an increase in their activity in the range of doses that cause stimulation of seedling growth. We showed that changes in the balance among different classes of phytohormones were probably involved in the acceleration of plant growth after irradiation of seeds using stimulating doses. Gamma irradiation of barley seeds significantly influenced the development of plants during the growing season. After irradiation with stimulating doses, we observed a reduction in the duration of the initial stages of ontogenesis; the phase of full ripeness occurred 5-7 days earlier than in the controls. The manifestation of the effect of irradiation depended on the conditions in which the plants developed. During the growing season of 2014, which was a dry year, plants originating from the irradiated seeds showed an increase in the number of productive stems, which led to an increase in yield by 34-38%; during the optimal 2015 season, an increase in the number of grains per spike caused an increase in yield by 8-29%. Therefore, our field study has shown that at least some hormetic effects can occur in the field. Irradiation of seeds can increase field germination, stimulate the growth and development of plants and increase their resistance to unfavourable environmental conditions. A more complete understanding of the underlying mechanisms of hormesis is needed to exploit its potential benefits in crop production.

Laryngeal and tracheobronchial cough in anesthetized dogs

1994 ◽  
Vol 76 (6) ◽  
pp. 2672-2679 ◽  
Author(s):  
M. Tatar ◽  
G. Sant′Ambrogio ◽  
F. B. Sant′Ambrogio
Keyword(s):  
Citric Acid ◽  
Mechanical Stimulation ◽  
Esophageal Pressure ◽  
Afferent Fibers ◽  
Anesthetized Dogs ◽  
Conduction Cooling ◽  
Chemical Stimuli ◽  
Alpha Chloralose ◽  
Tracheal Bifurcation ◽  
Stimulation Of

Tussigenic sensitivity of laryngeal and tracheobronchial regions to mechanical and chemical stimuli was compared in 22 urethan-alpha-chloralose-anesthetized dogs. In addition, the contribution of myelinated and unmyelinated vagal fibers in mediating laryngeal and tracheobronchial cough was investigated. The intensity of cough was evaluated from changes in esophageal pressure. Whereas all mechanical stimulations and citric acid inhalations into tracheobronchial region elicited cough, only 56.7% of mechanical stimulation and 33.3% of citric acid challenges to larynx were effective. The intensity of tracheobronchial cough was significantly higher than that of laryngeal cough. When mechanical stimulation was conducted under visual control (bronchofiberscope), cough elicitability was found to be higher from tracheal bifurcation and main stem bronchi (62.5–87.5%) than from any laryngeal structure (0–42.9%). During partial block of vagal conduction (cooling to 6 degrees C), mechanical and citric acid tracheobronchial stimulations failed to elicit cough and mechanical laryngeal stimulation was effective only in 1 of 10 dogs. Intensity of cough was strongly decreased when mechanical stimulation followed capsaicin administration into trachea (0.3 ml; 100 micrograms/ml) or intravenously (10 micrograms/kg). We conclude that, in anesthetized dogs, stimulation of tracheobronchial region is more effective and prompt in eliciting cough than stimulation of larynx, myelinated vagal afferent fibers play an important role in mediating mechanically and citric acid-induced tracheobronchial cough and mechanically induced laryngeal cough, and stimulation of tracheobronchial and pulmonary capsaicin-sensitive receptors strongly inhibits mechanically induced cough.

scholarly journals Prostaglandin E2 sensitizes the cough reflex centrally via EP3 receptor-dependent activation of NaV 1.8 channels

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Al-Shaimaa A. Al-Kandery ◽  
Muddanna S. Rao ◽  
Ahmed Z. El-Hashim
Keyword(s):  
Citric Acid ◽  
Nucleus Tractus Solitarius ◽  
Whole Body ◽  
Prostaglandin E ◽  
Cough Reflex ◽  
Trpv1 Antagonist ◽  
Underlying Mechanisms ◽  
Set Up ◽  
Guinea Pig Model ◽  
Ep3 Receptor

Abstract Background Cough hypersensitivity is a major characteristic feature associated with several types of cough, including chronic cough, but its underlying mechanisms remain to be fully understood. Inflammatory mediators, such as prostaglandin E2 (PGE2), have been implicated in both peripheral induction and sensitization of the cough reflex. In this study, using a conscious guinea pig model of cough, we investigated whether PGE2 can sensitize the cough reflex via central actions and, if so, via which mechanisms. Methods All drugs were administered by intracerebroventricular (i.c.v.) route and whole-body plethysmograph set-up was used for both induction, using aerosolized citric acid (0.2 M), and recording of cough. Immunohistochemistry was performed to confirm the expression of NaV 1.8 channels in the nucleus tractus solitarius (nTS). Results We show that both PGE2 and the non-selective EP1/EP3 agonist, sulprostone, dose-dependently enhanced the citric acid-induced cough (P ≤ 0.001, P ≤ 0.01, respectively). Pretreatment with the EP1 antagonist, ONO-8130, did not affect the sulprostone-induced cough sensitization, whilst the EP3 antagonist, L-798,106, dose-dependently inhibited this effect (P ≤ 0.05). Furthermore, treatment with either the EP2 agonist, butaprost or the EP4 agonist, L-902,688, had no effect on cough sensitization. Additionally, pretreatment with either the TRPV1 antagonist, JNJ-17203212 or the TRPA1 antagonist, HC-030031, alone or in combination, nor with the NaV 1.1, 1.2, 1.3, 1.4, 1.6 and 1.7 channel blocker, tetrodotoxin, had any effect on the cough. In contrast, pretreatment with the NaV 1.8 antagonist, A-803467, dose-dependently inhibited this effect (P ≤ 0.05). Furthermore, NaV 1.8 channels were shown to be expressed in the nTS. Conclusion Collectively, our findings show that PGE2 sensitizes the cough reflex centrally via EP3 receptor-dependent activation of NaV 1.8 but independently of TRPV1,TRPA1 and TTX-sensitive sodium channel activation. These results indicate that PGE2 plays an important role in central sensitization of the cough reflex and suggest that central EP3 receptors and/or NaVv 1.8 channels may represent novel antitussive molecular targets. Graphical Abstract

scholarly journals Are COVID-19 mitigation measures reducing preterm birth rate in China?

2021 ◽  
Vol 6 (8) ◽  
pp. e006359
Author(s):  
Zheng Bian ◽  
Xiaoxian Qu ◽  
Hao Ying ◽  
Xiaohua Liu
Keyword(s):  
Preterm Birth ◽  
Birth Rate ◽  
Time Window ◽  
Time Windows ◽  
Mitigation Measures ◽  
Late Preterm Birth ◽  
Child Morbidity ◽  
Preterm Birth Rate ◽  
Underlying Mechanisms ◽  
The Impact

ObjectivePreterm birth is the leading cause of child morbidity and mortality globally. We aimed to determine the impact of the COVID-19 mitigation measures implemented in China on 23 January 2020 on the incidence of preterm birth in our institution.DesignLogistic regression analysis was used to investigate the association between the national COVID-19 mitigation measures implemented in China and the incidence of preterm birth.SettingShanghai First Maternity and Infant Hospital, Shanghai China.ParticipantsAll singleton deliveries abstracted from electronic medical record between 1 January 2014 to 31 December 2020.Main outcome measuresPreterm birth rate.ResultsData on 164 107 singleton deliveries were available. COVID-19 mitigation measures were consistently associated with significant reductions in preterm birth in the 2-month, 3-month, 4-month, 5-month time windows after implementation (+2 months, OR 0.80, 95% CI 0.69 to 0.94; +3 months, OR 0.83, 95% CI 0.73 to 0.94; +4 months, OR 0.82, 95% CI 0.73 to 0.92; +5 months, OR 0.84, 95% CI 0.76 to 0.93). These reductions in preterm birth were obvious across various degrees of prematurity, but were statistically significant only in moderate-to-late preterm birth (32 complete weeks to 36 weeks and 6 days) subgroup. The preterm birth difference disappeared gradually after various restrictions were removed (7th–12th month of 2020, OR 1.02, 95% CI 0.94 to 1.11). There was no difference in stillbirth rate across the study time window.ConclusionSubstantial decreases in preterm birth rates were observed following implementation of the national COVID-19 mitigation measures in China. Further study is warranted to explore the underlying mechanisms associated with this observation.

scholarly journals The Connectivity Index: An Effective Metric for Grading Epileptogenicity

2019 ◽  
Author(s):  
Qi Yan ◽  
Nicolas Gaspard ◽  
Hitten P Zaveri ◽  
Hal Blumenfeld ◽  
Lawrence J. Hirsch ◽  
...  
Keyword(s):  
Average Distance ◽  
Single Pulse ◽  
Brain Regions ◽  
Control Site ◽  
Connectivity Index ◽  
Evoked Responses ◽  
Seizure Onset ◽  
Seizure Onset Zone ◽  
Site Of Stimulation ◽  
Stimulation Of

AbstractObjectiveTo investigate the performance of a metric of functional connectivity to classify and grade the excitability of brain regions based on evoked potentials to single pulse electrical stimulation (SPES).MethodsPatients who received 1-Hz frequency stimulation between 2003 and 2014 at Yale at prospectively selected contacts were included. The stimulated contacts were classified as seizure onset zone (SOZ), highly irritative zone (IZp) or control. Response contacts were classified as seizure onset zone (SOZ), active interictal (IZp), quiet or other. The normalized number of responses was defined as the number of contacts with any evoked responses divided by the total number of recorded contacts, and the normalized distance is the ratio of the average distance between the site of stimulation and sites of evoked responses to the average distances between the site of stimulation and all other recording contacts. A new metric we labeled the connectivity index (CI) is defined as the product of the two values.Results57 stimulation-sessions in 22-patients were analyzed. The connectivity index (CI) of the SOZ was higher than control (median CI of 0.74 vs. 0.16, p = 0.0002). The evoked responses after stimulation of SOZ were seen at further distance compared to control (median normalized distance 0.96 vs. 0.62, p = 0.0005). It was 1.8 times more likely to record a response at SOZ than in non-epileptic contacts after stimulation of a control site. Habitual seizures were triggered in 27% of patients and 35 % of SOZ contacts (median stimulation intensity 4 mA) but in none of the control or IZp contacts. Non-SOZ contacts in multifocal or poor surgical outcome cases had a higher CI than non-SOZ contacts in those with localizable onsets (medians CI of 0.5 vs. 0.12, p = 0.04). There was a correlation between the stimulation current intensity and the normalized number of evoked responses (r = + 0.49, p 0.01) but not with distance (r = + 0.1, p 0.64)ConclusionsWe found enhanced connectivity when stimulating the SOZ compared to stimulating control contacts; responses were more distant as well. Habitual auras and seizures provoked by SPES were highly predictive of brain sites involved in seizure generation.

Influence of Post-Injection Parameters on Soot Formation and Oxidation in a Common-Rail-Diesel Engine Using Multi-Color-Pyrometry

2012 ◽  
Author(s):  
Christophe Barro ◽  
Frédéric Tschanz ◽  
Peter Obrecht ◽  
Konstantinos Boulouchos
Keyword(s):  
Oxidation Rate ◽  
Time Window ◽  
Soot Formation ◽  
General Rule ◽  
Soot Oxidation ◽  
Lower Amount ◽  
Post Injection ◽  
Heat Addition ◽  
Underlying Mechanisms ◽  
A Minor

The emission trade-off between soot and NOx is an issue of major concern in automotive diesel applications. Measures need to be taken both on the engine and on the aftertreatment sides in order to optimize the engine emissions while maintaining the highest possible efficiency. It is known that post injections have a potential for exhaust soot reduction without any significant influence in the NOx emissions. However, an accurate and general rule of how to parameterize a post injection such that it provides a maximum reduction of soot emissions does not exist. Moreover, the underlying mechanisms are not understood in detail. The experimental investigation presented here provides insight into the fundamental mechanisms of soot formation and reduction due to post injections under different turbulence and reaction kinetic conditions. In parallel to the measurement of soot elementary carbon in the exhaust (using a Photo Acoustic Soot Sensor), the in-cylinder soot formation and oxidation process have been investigated with an Optical Light Probe (OLP). This sensor provides crank angle resolved information about the in-cylinder soot evolution. The experiments confirm conclusions of earlier works that soot reduction due to a post injection is mainly based on two reasons: increased turbulence (from the post injection) during soot oxidation and lower soot formation due to lower amount of fuel in the main combustion at similar load conditions. A third effect of heat addition during the soot oxidation, which was often mentioned in the literature, could not be confirmed. In addition, the experiments show that variations of turbulence (from swirl) and reaction kinetics have a minor influence on the diffusion controlled heat release rate. However, the time phasing of the soot evolution is highly influenced by these variations with only small changes in the peak soot concentration. It is shown that the soot reduction of a post injection depends on the timing. More precisely, the soot reduction capability of a post injection decreases rapidly as soon as its timing is late in the soot oxidation phase. The soot oxidation rate can only be improved by increased turbulence and heat addition from the post injection in a time window before the in-cylinder soot peak occurs. Depending on EGR and swirl level, a maximum dwell time can be defined after which the post injection effect becomes counterproductive with respect to the soot oxidation rate.

Neuromuscular Physiology of the Longitudinal Muscle of the Earthworm, Lumbricus Terrestris

1974 ◽  
Vol 60 (2) ◽  
pp. 453-467
Author(s):  
C. D. DREWES ◽  
R. A. PAX
Keyword(s):  
Time Course ◽  
Longitudinal Muscle ◽  
Lumbricus Terrestris ◽  
Single Pulse ◽  
Repetitive Stimulation ◽  
Muscle Fibres ◽  
Mechanical Responses ◽  
Segmental Nerve ◽  
Earthworm Lumbricus ◽  
Stimulation Of

1. Patterns of innervation of the longitudinal muscle of the earthworm, Lumbricus terrestris, were examined electrophysiologically. 2. The longitudinal musculature of a segment is innervated by relatively few axons, a fast and slow axon being present in segmental nerve I and in the double nerve, segmental nerve II-III. 3. Single-pulse stimulation of the fast axon produces large external muscle potentials and small twitch-like contractions, which with repetitive stimulation are antifacilitating. 4. Repetitive stimulation of the slow axon produces large, slowly developing and sustained mechanical responses, with electrical and mechanical responses showing summation and facilitation. 5. The amplitude and time course of slow mechanical responses are related to the frequency of stimulation. 6. Individual longitudinal muscle fibres are innervated by either the fast or slow axon in a segmental nerve, or by both fast and slow axons. 7. No evidence was found for peripheral inhibitory innervation of the longitudinal muscle.

scholarly journals Glucose stimulates somatostatin secretion in pancreatic δ-cells by cAMP-dependent intracellular Ca2+ release

2019 ◽  
Vol 151 (9) ◽  
Author(s):  
Geoffrey Denwood ◽  
Andrei Tarasov ◽  
Albert Salehi ◽  
Elisa Vergari ◽  
Reshma Ramracheya ◽  
...  
Keyword(s):  
Electrical Activity ◽  
Secretory Vesicles ◽  
Glucose Levels ◽  
Somatostatin Secretion ◽  
Elevated Glucose ◽  
Mouse Islets ◽  
Underlying Mechanisms ◽  
Fold Stimulation ◽  
Cyclase Activator ◽  
Stimulation Of

Somatostatin secretion from pancreatic islet δ-cells is stimulated by elevated glucose levels, but the underlying mechanisms have only partially been elucidated. Here we show that glucose-induced somatostatin secretion (GISS) involves both membrane potential-dependent and -independent pathways. Although glucose-induced electrical activity triggers somatostatin release, the sugar also stimulates GISS via a cAMP-dependent stimulation of CICR and exocytosis of somatostatin. The latter effect is more quantitatively important and in mouse islets depolarized by 70 mM extracellular K+, increasing glucose from 1 mM to 20 mM produced an ∼3.5-fold stimulation of somatostatin secretion, an effect that was mimicked by the application of the adenylyl cyclase activator forskolin. Inhibiting cAMP-dependent pathways with PKI or ESI-05, which inhibit PKA and exchange protein directly activated by cAMP 2 (Epac2), respectively, reduced glucose/forskolin-induced somatostatin secretion. Ryanodine produced a similar effect that was not additive to that of the PKA or Epac2 inhibitors. Intracellular application of cAMP produced a concentration-dependent stimulation of somatostatin exocytosis and elevation of cytoplasmic Ca2+ ([Ca2+]i). Both effects were inhibited by ESI-05 and thapsigargin (an inhibitor of SERCA). By contrast, inhibition of PKA suppressed δ-cell exocytosis without affecting [Ca2+]i. Simultaneous recordings of electrical activity and [Ca2+]i in δ-cells expressing the genetically encoded Ca2+ indicator GCaMP3 revealed that the majority of glucose-induced [Ca2+]i spikes did not correlate with δ-cell electrical activity but instead reflected Ca2+ release from the ER. These spontaneous [Ca2+]i spikes are resistant to PKI but sensitive to ESI-05 or thapsigargin. We propose that cAMP links an increase in plasma glucose to stimulation of somatostatin secretion by promoting CICR, thus evoking exocytosis of somatostatin-containing secretory vesicles in the δ-cell.

Robust Changes of Afferent-Induced Excitation in the Rat Spinal Dorsal Horn After Conditioning High-Frequency Stimulation

2000 ◽  
Vol 83 (4) ◽  
pp. 2412-2420 ◽  
Author(s):  
Hiroshi Ikeda ◽  
Tatsuya Asai ◽  
Kazuyuki Murase
Keyword(s):  
Dorsal Horn ◽  
High Frequency ◽  
Low Frequency ◽  
Single Pulse ◽  
High Frequency Stimulation ◽  
Neuronal Excitation ◽  
Low Frequency Stimulation ◽  
Frequency Stimulation ◽  
Stimulation Of

We investigated the neuronal plasticity in the spinal dorsal horn and its relationship with spinal inhibitory networks using an optical-imaging method that detects neuronal excitation. High-intensity single-pulse stimulation of the dorsal root activating both A and C fibers evoked an optical response in the lamina II (the substantia gelatinosa) of the dorsal horn in transverse slices of 12- to 25-day-old rat spinal cords stained with a voltage-sensitive dye, RH-482. The optical response, reflecting the net neuronal excitation along the slice-depth, was depressed by 28% for more than 1 h after a high-frequency conditioning stimulation of A fibers in the dorsal root (3 tetani of 100 Hz for 1 s with an interval of 10 s). The depression was not induced in a perfusion solution containing an NMDA antagonist,dl-2-amino-5-phosphonovaleric acid (AP5; 30 μM). In a solution containing the inhibitory amino acid antagonists bicuculline (1 μM) and strychnine (3 μM), and also in a low Cl−solution, the excitation evoked by the single-pulse stimulation was enhanced after the high-frequency stimulation by 31 and 18%, respectively. The enhanced response after conditioning was depotentiated by a low-frequency stimulation of A fibers (0.2–1 Hz for 10 min). Furthermore, once the low-frequency stimulation was applied, the high-frequency conditioning could not potentiate the excitation. Inhibitory transmissions thus regulate the mode of synaptic plasticity in the lamina II most likely at afferent terminals. The high-frequency conditioning elicits a long-term depression (LTD) of synaptic efficacy under a greater activity of inhibitory amino acids, but it results in a long-term potentiation (LTP) when inhibition is reduced. The low-frequency preconditioning inhibits the potentiation induction and maintenance by the high-frequency conditioning. These mechanisms might underlie robust changes of nociception, such as hypersensitivity after injury or inflammation and pain relief after electrical or cutaneous stimulation.

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