Diaphragm reinnervation by laryngeal motoneurons

1993 ◽  
Vol 75 (2) ◽  
pp. 639-647 ◽  
Author(s):  
F. Baldissera ◽  
P. Cavallari ◽  
G. Marini ◽  
G. Tredici

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.

1992 ◽  
Vol 72 (2) ◽  
pp. 643-649 ◽  
Author(s):  
B. N. Van Vliet ◽  
M. Uenishi

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.


2020 ◽  
Vol 132 (6) ◽  
pp. 2000-2007 ◽  
Author(s):  
Soroush Niketeghad ◽  
Abirami Muralidharan ◽  
Uday Patel ◽  
Jessy D. Dorn ◽  
Laura Bonelli ◽  
...  

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.


2020 ◽  
pp. 13-17
Author(s):  
Dmitrii Aleksandrovich Lopyn ◽  
Stanislav Valerevich Rybchynskyi ◽  
Dmitrii Evgenevich Volkov

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.


Author(s):  
Stanislav Kuzmin ◽  
Irina Polyanskaya

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.


1975 ◽  
Vol 38 (2) ◽  
pp. 418-429 ◽  
Author(s):  
L. M. Aitkin ◽  
J. Boyd

The responses of 146 cerebellar neurons to tone stimuli were studied in 29 cats anesthetized with chloralose-urethan and in 7 decerebrate preparations. Units were classified as onset or sustained firing. Onset spikes occurred on stimulation of either ear and showed binaural facilitation, while sustained discharges were frequently only excited by monaural stimulation. The latent periods of sustained discharges appeared to be shorter than those of onset responses, and sustained discharges were also more sharply tuned than the onset units. Evidence was presented suggesting that onset responses reflected input from the inferior colliculus and sustained responses, the cochlear nucleus. The sterotyped facilitatory behavior of onset units suggested that a maximal discharge might occur if sounds were of equal intensity at each ear; 26 neurons were examined with variable interaural time or intensity differences and 10 of these exhibited maximal firing when the interaural time and intensity difference was zero--i.e., if the sound was located directly in front of the head.


2021 ◽  
Vol 14 (1) ◽  
pp. 131-140
Author(s):  
Emily A. Mankin ◽  
Zahra M. Aghajan ◽  
Peter Schuette ◽  
Michelle E. Tran ◽  
Natalia Tchemodanov ◽  
...  

1911 ◽  
Vol 14 (3) ◽  
pp. 217-234 ◽  
Author(s):  
G. Canby Robinson ◽  
George Draper

In hearts showing auricular fibrillation mechanical stimulation of the right vagus nerve causes, as a rule, marked slowing or stoppage of ventricular rhythm, without producing any appreciable effect in the electrocardiographic record of the auricular fibrillation. The ventricular pauses are apparently due to the blocking of stimuli from the auricles. The force of ventricular systole is distinctly weakened for several beats after vagus stimulation, and ectopic ventricular systoles have been seen in several instances, apparently the result of the vagus action. There may, in some cases, be lowered excitability of the ventricles, while no constant change is seen in the size of the electrical complexes representing ventricular systole.


2015 ◽  
Vol 114 (5) ◽  
pp. 2588-2599 ◽  
Author(s):  
Gijs Joost Brouwer ◽  
Vanessa Arnedo ◽  
Shani Offen ◽  
David J. Heeger ◽  
Arthur C. Grant

Functional magnetic resonance imaging (fMRI) was used to measure activity in human somatosensory cortex and to test for cross-digit suppression. Subjects received stimulation (vibration of varying amplitudes) to the right thumb (target) with or without concurrent stimulation of the right middle finger (mask). Subjects were less sensitive to target stimulation (psychophysical detection thresholds were higher) when target and mask digits were stimulated concurrently compared with when the target was stimulated in isolation. fMRI voxels in a region of the left postcentral gyrus each responded when either digit was stimulated. A regression model (called a forward model) was used to separate the fMRI measurements from these voxels into two hypothetical channels, each of which responded selectively to only one of the two digits. For the channel tuned to the target digit, responses in the left postcentral gyrus increased with target stimulus amplitude but were suppressed by concurrent stimulation to the mask digit, evident as a shift in the gain of the response functions. For the channel tuned to the mask digit, a constant baseline response was evoked for all target amplitudes when the mask was absent and responses decreased with increasing target amplitude when the mask was concurrently presented. A computational model based on divisive normalization provided a good fit to the measurements for both mask-absent and target + mask stimulation. We conclude that the normalization model can explain cross-digit suppression in human somatosensory cortex, supporting the hypothesis that normalization is a canonical neural computation.


2000 ◽  
Vol 89 (1) ◽  
pp. 139-142 ◽  
Author(s):  
Robert L. Coon ◽  
Patrick J. Mueller ◽  
Philip S. Clifford

The canine cervical trachea has been used for numerous studies regarding the neural control of tracheal smooth muscle. The purpose of the present study was to determine whether there is lateral dominance by either the left or right vagal innervation of the canine cervical trachea. In anesthetized dogs, pressure in the cuff of the endotracheal tube was used as an index of smooth muscle tone in the trachea. After establishment of tracheal tone, as indicated by increased cuff pressure, either the right or left vagus nerve was sectioned followed by section of the contralateral vagus. Sectioning the right vagus first resulted in total loss of tone in the cervical trachea, whereas sectioning the left vagus first produced either a partial or no decrease in tracheal tone. After bilateral section of the vagi, cuff pressure was recorded during electrical stimulation of the rostral end of the right or left vagus. At the maximum current strength used, stimulation of the left vagus produced tracheal constriction that averaged 28.5% of the response to stimulation of the right vagus (9.0 ± 1.8 and 31.6 ± 2.5 mmHg, respectively). In conclusion, the musculature of cervical trachea in the dog appears to be predominantly controlled by vagal efferents in the right vagus nerve.


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