Antagonistic interaction of laryngeal and central chemoreceptor respiratory reflexes

1992 ◽  
Vol 72 (2) ◽  
pp. 643-649 ◽  
Author(s):  
B. N. Van Vliet ◽  
M. Uenishi
Keyword(s):  
Superior Laryngeal Nerve ◽  
Control Mechanisms ◽  
Respiratory Drive ◽  
Absolute Level ◽  
Afferent Stimulation ◽  
Airway Reflex ◽  
Central Inspiratory Activity ◽  
Inspiratory Activity ◽  
The Right ◽  
Stimulation Of

Stimulation of laryngeal afferent fibers evokes a profound reflex inhibition of central respiratory drive. The interaction of this airway reflex with chemoreceptive ventilatory control mechanisms is poorly understood. The present study was undertaken to determine whether there is significant interaction between the effects of central chemoreceptor and laryngeal afferent stimulation on central inspiratory activity and, if so, to also determine the nature of the interaction. The effect of electrical stimulation of the superior laryngeal nerve (SLN) on the timing and intensity of central inspiratory activity was determined from the rectified and filtered phrenic neurogram in 10 dogs. Each dogs was decerebrated, artificially ventilated, vagotomized, and had the carotid bodies denervated. In each case, stimulation of the right SLN at 3 and 10 Hz caused a frequency-dependent slowing or arrest of central inspiratory activity. Increases in arterial PCO2 (PaCO2) attenuated the absolute level of inhibition of central inspiratory activity recorded during both SLN stimulation and control periods. Tp clarify the nature of the interaction between chemoreceptor and laryngeal afferent stimulation, the relationship between PaCO2 and central inspiratory activity was investigated during stimulation of the SLN at 0, 3, and 10 Hz. Control central inspiratory activity increased as a sigmoidal function of PaCO2. This sigmoidal relationship was greatly depressed during SLN stimulation but did not appear to be shifted along the PaCO2 axis. The results of this study therefore suggest that the interaction between central chemoreceptor and laryngeal afferent stimulation is multiplicative: the inhibition of the central inspiratory activity is mediated by an attenuation and not a resetting of central chemoreflexes.

Influences of superior laryngeal afferent stimulation on expiratory activity in cats

1988 ◽  
Vol 65 (1) ◽  
pp. 385-392 ◽  
Author(s):  
F. Bongianni ◽  
M. Corda ◽  
G. Fontana ◽  
T. Pantaleo
Keyword(s):  
Superior Laryngeal Nerve ◽  
Laryngeal Nerve ◽  
Tetanic Stimulation ◽  
Bötzinger Complex ◽  
Dependent Activity ◽  
Inspiratory Activity ◽  
Polysynaptic Reflex ◽  
Expiratory Muscles ◽  
Excitatory Responses ◽  
Stimulation Of

The effects of superior laryngeal nerve (SLN) stimulation on the activity of the expiratory muscles and medullary expiration-related (ER) neurons were investigated in 24 pentobarbital-anesthetized cats. In some experiments the animals were also paralyzed and artificially ventilated. Sustained tetanic stimulation of SLN consistently caused an apneic response associated with the appearance of tonic CO2-dependent activity in the expiratory muscles and in ER neurons located in the caudal ventral respiratory group (VRG) and the Botzinger complex. Single shocks or brief tetani at the same stimulation intensities failed to evoke excitatory responses in the expiratory muscles and in the vast majority of ER neurons tested. At higher stimulation strengths, single shocks or short tetani elicited excitatory responses in the expiratory muscles (20- to 35-ms latency) and in the majority of ER neurons of the caudal VRG (7.5- to 15.5-ms latency). These responses were obtained only during the expiratory phase and proved to be CO2 independent. On the contrary, only inhibitory responses were evoked in the activity of Botzinger complex neurons. The observed tonic expiratory activity most likely represents a disinhibition phenomenon due to the suppression of inspiratory activity; activation of expiratory muscles at higher stimulation intensities appears to be a polysynaptic reflex mediated by ER neurons of the caudal VRG but not by Botzinger complex neurons.

Respiratory motor responses to cranial nerve afferent stimulation in rats

1996 ◽  
Vol 271 (4) ◽  
pp. R1054-R1062 ◽  
Author(s):  
F. Hayashi ◽  
D. R. McCrimmon
Keyword(s):  
Cranial Nerve ◽  
Superior Laryngeal Nerve ◽  
Single Pulse ◽  
Short Latency ◽  
Lung Inflation ◽  
Dorsal Respiratory Group ◽  
Inspiratory Activity ◽  
Pharyngeal Branch ◽  
Pulse Stimulation ◽  
Stimulation Of

It was hypothesized that, because rats appear to lack a prominent disynaptic projection from the dorsal respiratory group to phrenic motoneurons (Phr), they would lack the short-latency excitation of Phr output seen in cats in response to stimulation of some cranial nerve afferents. Single-pulse superior laryngeal nerve (SLN) stimulation elicited a short-latency bilateral excitation of glossopharyngeal (IX) and hypoglossal (XII) nerves and an ipsilateral excitation of pharyngeal branch of vagus (PhX) in 67% of rats, but no excitation of Phr. Vagus (X) stimulation elicited a bilateral excitation of Phr and a predominantly ipsilateral excitation of IX and PhX. Single-pulse stimulation of SLN or X also elicited longer-latency, bilateral decreases in activity of all recorded nerves. Repetitive stimulation (50 Hz) of SLN or X suppressed inspiratory activity and prolonged expiration. Lung inflation (7.5 cmH2O) inhibited Phr and PhX activity; X stimulation inhibited Phr but prolonged PhX activity. In conclusion, rats predictably lack the SLN-induced short latency Phr excitation but exhibit other short latency reflexes for which the underlying circuitry is not clear.

Synergism between the canine left and right hemidiaphragms

2003 ◽  
Vol 94 (5) ◽  
pp. 1757-1765 ◽  
Author(s):  
André De Troyer ◽  
Matteo Cappello ◽  
Nathalie Meurant ◽  
Pierre Scillia
Keyword(s):  
Intrathoracic Pressure ◽  
Respiratory Drive ◽  
Additive Interaction ◽  
Quiet Breathing ◽  
Rib Cage ◽  
Radiographic Measurements ◽  
Airway Opening ◽  
Left And Right ◽  
The Right ◽  
Stimulation Of

Expansion of the lung during inspiration results from the coordinated contraction of the diaphragm and several groups of rib cage muscles, and we have previously shown that the changes in intrathoracic pressure generated by the latter are essentially additive. In the present studies, we have assessed the interaction between the right and left hemidiaphragms in anesthetized dogs by comparing the changes in airway opening pressure (ΔPao) obtained during simultaneous stimulation of the two phrenic nerves (measured ΔPao) to the sum of the ΔPao values produced by their separate stimulation (predicted ΔPao). The measured ΔPao was invariably greater than the predicted ΔPao, and the ratio between these two values increased gradually as the stimulation frequency was increased; the ratio was 1.10 ± 0.01 ( P < 0.05) for a frequency of 10 Hz, whereas for a frequency of 50 Hz it amounted to 1.49 ± 0.05 ( P < 0.001). This interaction remained unchanged after the rib cage was stiffened and its compliance was made linear, thus indicating that the load against which the diaphragm works is not a major determinant. However, radiographic measurements showed that stimulation of one phrenic nerve extends the inactive hemidiaphragm toward the sagittal midplane and reduces the caudal displacement of the central portion of the diaphragmatic dome. As a result, the volume swept by the contracting hemidiaphragm is smaller than the volume it displaces when the contralateral hemidiaphragm also contracts. These observations indicate that 1) the left and right hemidiaphragms have a synergistic, rather than additive, interaction on the lung; 2) this synergism operates already during quiet breathing and increases in magnitude when respiratory drive is greater; and 3) this synergism is primarily related to the configuration of the muscle.

Respiratory effects of progressive asphyxia in rabbit pups and adult rabbits

1984 ◽  
Vol 56 (4) ◽  
pp. 940-947 ◽  
Author(s):  
T. Trippenbach ◽  
R. Affleck ◽  
G. Kelly
Keyword(s):  
Time Course ◽  
Age Groups ◽  
Esophageal Pressure ◽  
Muscle Dysfunction ◽  
Respiratory Drive ◽  
Similar Time ◽  
Airway Occlusion ◽  
Temporal Relationships ◽  
Central Inspiratory Activity ◽  
Inspiratory Activity

Effects of prolonged airway occlusion were investigated in anesthetized and vagotomized 9-to 15-day-old pups and adult rabbits. The changes and temporal relationships between “integrated” phrenic activity, external intercostal electromyogram (INT), and esophageal pressure (Pes) were examined. Each occlusion resulted in hyperpnea, apnea, and gasping. Blood pressure recorded during the occlusion showed a marked decrease. During hyperpnea, the rate of changes and maximal amplitudes in Pes and INT were similar in both age groups. The increase in integrated phrenic activity (PHR) was significantly greater in young rabbits. In both age groups, changes in INT during gasping followed a similar time course and exceeded those in PHR. Maximal values of the three parameters were concurrent in adults, whereas the increase in INT peaked later than PHR and Pes in rabbit pups. In adult rabbits, PHR, INT, and Pes, during the last gasp, decreased to the values of the first hyperpnea breath. In rabbit pups, Pes of the last gasp decreased significantly below this value while INT was still elevated. This Pes decrease could result from inspiratory muscle dysfunction in the pups. Thus in rabbit pups, 1) greater changes in PHR were necessary to produce a given change in Pes than in adult rabbits; 2) activity of the external intercostal muscles was not efficient in developing pressure under conditions of asphyxia; and 3) the independent activation of diaphragmatic and intercostal motoneurons is not of vagal origin. Additionally, the results led us to conclude that Pes can serve as a close approximation of respiratory drive in adult rabbits. This parameter, however, cannot be used as an index of central inspiratory activity during gasping in rabbit pups.

Diaphragm reinnervation by laryngeal motoneurons

1993 ◽  
Vol 75 (2) ◽  
pp. 639-647 ◽  
Author(s):  
F. Baldissera ◽  
P. Cavallari ◽  
G. Marini ◽  
G. Tredici
Keyword(s):  
Histological Analysis ◽  
Distal Stump ◽  
Inspiratory Activity ◽  
The Right ◽  
Comparable Amplitude ◽  
Sustained Responses ◽  
Laryngeal Motoneurons ◽  
Normal Diaphragm ◽  
Stimulation Of ◽  
Nembutal Anesthesia

Inspiratory activity of the paralyzed diaphragm was restored by reinnervation with brain stem laryngeal motoneurons. In 10 anesthetized cats, the right recurrent laryngeal nerve (RLN) was cut and anastomosed to the distal stump of either one or both roots (C5-C6) of the ipsilateral phrenic nerve. Three to four months later, reinnervation was assessed under deep anesthesia by the reappearance in the paralyzed diaphragm of 1) direct electromyographic (EMG) responses after electrical stimulation of the RLN and 2) spontaneous inspiratory bursts. Serial radiography, performed on five animals, revealed diaphragmatic excursions of comparable amplitude on the normal and reinnervated sides. Six to twelve months after anastomosis, laparotomy (performed under Nembutal anesthesia) allowed inspection and EMG recording of the spontaneous inspiratory contractions of the reinnervated areas and their sustained responses to tetanic RLN stimulation. Inspiratory discharges showed a ramplike recruitment similar to that of the normal diaphragm. Although the RLN contains a number of expiratory axons, multiple-site recordings disclosed expiratory EMG discharges only once. Histological analysis confirmed the substitution of phrenic axons by regenerating RLN fibers.

Inputs from upper airway affect firing of respiratory-associated midbrain neurons

1997 ◽  
Vol 83 (1) ◽  
pp. 196-203 ◽  
Author(s):  
Zibin Chen ◽  
Frederic L. Eldridge
Keyword(s):  
Mechanical Stimulation ◽  
Respiratory Activity ◽  
Superior Laryngeal Nerve ◽  
Upper Airway ◽  
Laryngeal Nerve ◽  
Neuronal Firing ◽  
Respiratory Drive ◽  
Midbrain Neurons ◽  
Rhythmic Firing ◽  
Stimulation Of

Chen, Zibin, and Frederic L. Eldridge. Inputs from upper airway affect firing of respiratory-associated midbrain neurons. J. Appl. Physiol. 83(1): 196–203, 1997.—In 16 decerebrated unanesthetized cats, we studied effects of neural inputs from upper airway on firing of 62 mesencephalic neurons that also developed respiratory-associated (RA) rhythmic firing when respiratory drive was high [Z. Chen, F. L. Eldridge, and P.G. Wagner. J. Physiol. (Lond.) 437: 305–325, 1991] and on firing of 16 neurons that did not develop the rhythmic firing (non-RA neurons). Activity in RA neurons increased after mechanical expansion of pharynx (45% of those tested) or larynx (68%) and after stimulation of glossopharyngeal (50%) or superior laryngeal nerves (77%). The increased neuronal firing occurred despite decreases or abolition of respiratory activity (expressed in phrenic nerve). Neuronal firing also increased after mechanical stimulation of nasal mucosa (66%) or by jets of air directed into the nares (48%) and after light brushing of nasal skin (∼40%). Most stimuli led to decreased firing in a smaller number of neurons, and some neurons showed no response. None of the non-RA neurons developed an increase of firing after any of the stimuli, although one had decreased firing after stimulation of the superior laryngeal nerve. We conclude that inputs from the upper airway and nasal skin have independent modulatory effects on the same mesencephalic neurons that are stimulated by ascending rhythmic RA input from the medulla. These findings may have relevance to generation of the sensation of dyspnea.

Phosphene perceptions and safety of chronic visual cortex stimulation in a blind subject

2020 ◽  
Vol 132 (6) ◽  
pp. 2000-2007 ◽  
Author(s):  
Soroush Niketeghad ◽  
Abirami Muralidharan ◽  
Uday Patel ◽  
Jessy D. Dorn ◽  
Laura Bonelli ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Adverse Events ◽  
Clinical Intervention ◽  
Occipital Cortex ◽  
Neuronal Population ◽  
Serious Adverse Events ◽  
Stimulation Parameters ◽  
The Right ◽  
Visual Cortical ◽  
Stimulation Of

Stimulation of primary visual cortices has the potential to restore some degree of vision to blind individuals. Developing safe and reliable visual cortical prostheses requires assessment of the long-term stability, feasibility, and safety of generating stimulation-evoked perceptions.A NeuroPace responsive neurostimulation system was implanted in a blind individual with an 8-year history of bare light perception, and stimulation-evoked phosphenes were evaluated over 19 months (41 test sessions). Electrical stimulation was delivered via two four-contact subdural electrode strips implanted over the right medial occipital cortex. Current and charge thresholds for eliciting visual perception (phosphenes) were measured, as were the shape, size, location, and intensity of the phosphenes. Adverse events were also assessed.Stimulation of all contacts resulted in phosphene perception. Phosphenes appeared completely or partially in the left hemifield. Stimulation of the electrodes below the calcarine sulcus elicited phosphenes in the superior hemifield and vice versa. Changing the stimulation parameters of frequency, pulse width, and burst duration affected current thresholds for eliciting phosphenes, and increasing the amplitude or frequency of stimulation resulted in brighter perceptions. While stimulation thresholds decreased between an average of 5% and 12% after 19 months, spatial mapping of phosphenes remained consistent over time. Although no serious adverse events were observed, the subject experienced mild headaches and dizziness in three instances, symptoms that did not persist for more than a few hours and for which no clinical intervention was required.Using an off-the-shelf neurostimulator, the authors were able to reliably generate phosphenes in different areas of the visual field over 19 months with no serious adverse events, providing preliminary proof of feasibility and safety to proceed with visual epicortical prosthetic clinical trials. Moreover, they systematically explored the relationship between stimulation parameters and phosphene thresholds and discovered the direct relation of perception thresholds based on primary visual cortex (V1) neuronal population excitation thresholds.

INFLUENCE OF RIGHT VENTRICULAR LEAD IMPLANTATION SITE CHOICE ON PACING EFFICIENCY

2020 ◽  
pp. 13-17
Author(s):  
Dmitrii Aleksandrovich Lopyn ◽  
Stanislav Valerevich Rybchynskyi ◽  
Dmitrii Evgenevich Volkov
Keyword(s):  
Heart Failure ◽  
Right Ventricular ◽  
Longitudinal Strain ◽  
Treatment Options ◽  
Global Longitudinal Strain ◽  
Optimal Method ◽  
Cardiac Stimulation ◽  
Ventricular Lead ◽  
The Right ◽  
Stimulation Of

Currently the electrophysiological treatment options have been considered to be the most effective for many patients with arrhythmogenic cardiomyopathies, as well as in those with arrhythmias on the background of heart failure. Currently, the dependence of efficiency of the pacemakers on the location of the electrodes has been proven. In order to study the effect of a myocardial dysynchrony on the effectiveness of pacing depending on the location of the right ventricular electrode, an investigation has been performed. This study comprised the patients with a complete atrioventricular block, preserved ejection fraction of the left ventricle (more than 50 %), with no history of myocardial infarction, who were implanted with the two−chamber pacemaker. It has been established that the best results were achieved with a stimulation of the middle and lower septal zone of the right ventricle, the worst ones were obtained with a stimulation of its apex. It has been found that the dynamics of the magnitude of segmental strains and a global longitudinal strain coincided with the dynamics of other parameters of the pacemaker effectiveness, which indicated the pathogenetic value of myocardial dysynchrony in the progression of heart failure after implantation of the pacemaker. Therefore it could be concluded that the studying of myocardial mobility by determining a longitudinal strain for assessing the functional state of the myocardium and the effectiveness of pacing is highly advisable. It is emphasized that the use of the latest strains−dependent techniques for cardiac performance evaluation in the patients with bradyarrhythmia have a great potential to predict the development of chronic heart failure and to choose the optimal method of physiological stimulation of the heart. Key words: right ventricular lead, cardiac stimulation, myocardial dyssynchrony.

СТИМУЛИРОВАНИЕ ПРАВОПОСЛУШНОГО ПОВЕДЕНИЯ ОСУЖДЕННЫХ В МЕСТАХ ЛИШЕНИЯ СВОБОДЫ В СОВЕТСКОМ И СОВРЕМЕННОМ РОССИЙСКОМ ЗАКОНОДАТЕЛЬСТВЕ

2020 ◽  
Author(s):  
Stanislav Kuzmin ◽  
Irina Polyanskaya
Keyword(s):  
Criminal Punishment ◽  
Personal Time ◽  
Labor Camps ◽  
Archival Documents ◽  
Legal Position ◽  
Executive System ◽  
The Right ◽  
Stimulation Of

Статья подготовлена на основе использования нормативных правовых актов и архивных документов различных исправительно-трудовых лагерей, указанных в сносках, что позволяет судить о территориальных рамках источников. Исследуется генезис становления и развития практики стимулирования правопослушного поведения осужденных посредством норм, не изменяющих их правовое положение в период отбывания уголовного наказания в виде лишения свободы на различных этапах функционирования исправительно-трудовой (уголовно-исполнительной) системы. На основе изученных документов можно сделать вывод, что в основу дифференциации поощрительных норм, распространявшихся на осужденных, положены следующие критерии: 1) поощрения, не изменяющие условия отбывания уголовного наказания в виде лишения свободы; 2) поощрения, изменяющие условия содержания осужденных. Из ранее применявшихся мер поощрений в современном уголовно-исполнительном законодательстве используются следующие: объявление благодарности с занесением в личное дело, материальное поощрение, право на дополнительную посылку, передачу и др. Среди других мер поощрения можно выделить увеличение времени ежедневной прогулки до двух часов для осужденных, содержащихся в строгих условиях отбывания наказания в колониях и тюрьмах. Также законодатель предусмотрел возможность проводить праздничные и выходные дни за пределами учреждения для осужденных, содержащихся в колониях-поселениях.The article is prepared on the basis of the use of normative legal acts and archival documents of various correctional labor camps mentioned in the footnotes, which allows to judge the territorial scope of the sources. The Genesis of formation and development of practice of stimulation of law-abiding behavior of condemned by means of the norms which are not changing their legal position during serving of criminal punishment in the form of imprisonment at various stages of functioning of correctional labor (criminal Executive) system is investigated. On the basis of the studied documents, it can be concluded that the basis for the differentiation of incentive norms that apply to convicts are the following criteria: 1) incentives that do not change the conditions of serving a criminal sentence in the form of imprisonment; 2) incentives that change the conditions of detention of convicts. Of the previously applied measures of incentives in the modern penal legislation the following are used: the announcement of gratitude with entering in personal time, material encouragement, the right to an additional parcel, transfer, etc. Among other measures of encouragement it is possible to allocate increase in time of daily walk to two hours for condemned detainees in strict conditions of serving of punishment in colonies and prisons. Also, the legislator provided the opportunity to spend holidays and weekends outside the institution for convicts held in colonies-settlements.

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