Responses to stimulation of the peripheral end of the right splanchnic nerve in the conscious calf

1979 ◽  
Vol 35 (3) ◽  
pp. 340-340
Author(s):  
A. V. Edwards ◽  
P. N. Furness
Keyword(s):  
Splanchnic Nerve ◽  
The Right ◽  
Stimulation Of

scholarly journals Rostral ventrolateral medullary but not medullary lateral tegmental field neurons mediate sympatho-sympathetic reflexes in cats

2010 ◽  
Vol 299 (5) ◽  
pp. R1269-R1278 ◽  
Author(s):  
Susan M. Barman ◽  
Hakan S. Orer
Keyword(s):  
Nmda Receptors ◽  
Nucleus Tractus Solitarius ◽  
Excitatory Amino Acid ◽  
Critical Role ◽  
Area Under The Curve ◽  
Splanchnic Nerve ◽  
Ventrolateral Medulla ◽  
Afferent Fibers ◽  
The Right ◽  
Stimulation Of

This study was designed to build on past work from this laboratory by testing the hypothesis that medullary lateral tegmental field (LTF) neurons play a critical role in mediating sympathoexcitatory responses to activation of sympathetic afferent fibers. We studied the effects of microinjection of N-methyl-d-aspartate (NMDA) or non-NMDA receptor antagonists or muscimol bilaterally into the LTF on the area under the curve of the computer-averaged sympathoexcitatory potential in the right inferior cardiac nerve elicited by short trains of stimuli applied to afferent fibers in the left inferior cardiac or left splanchnic nerve (CN, SN) of baroreceptor-denervated and vagotomized cats anesthetized with a mixture of diallylbarbiturate and urethane. In contrast to our hypothesis, sympathoexcitatory responses to stimulation of CN ( n = 5–7) or SN ( n = 4–7) afferent fibers were not significantly affected by these procedures. We then determined whether the rostral and caudal ventrolateral medulla (RVLM, CVLM) and nucleus tractus solitarius (NTS) were involved in mediating these reflexes. Blockade of non-NMDA, but not NMDA, receptors in the RVLM significantly reduced the area under the curve of the sympathoexcitatory responses to electrical stimulation of either CN ( P = 0.0110; n = 6) or SN ( P = 0.0131; n = 5) afferent fibers. Neither blockade of excitatory amino acid receptors nor chemical inactivation of CVLM or NTS significantly affected the responses. These data show that activation of non-NMDA receptors in the RVLM is a critical step in mediating the sympatho-sympathetic reflex.

Differential responses of regional sympathetic activity and blood flow to visceral afferent stimulation

2001 ◽  
Vol 280 (6) ◽  
pp. R1781-R1789 ◽  
Author(s):  
Hui-Lin Pan ◽  
Dwight D. Deal ◽  
Zemin Xu ◽  
Shao-Rui Chen
Keyword(s):  
Vascular Resistance ◽  
Cardiovascular Responses ◽  
Splanchnic Nerve ◽  
Visceral Afferents ◽  
Cardiovascular Reflexes ◽  
Efferent Activity ◽  
Blood Flows ◽  
The Right ◽  
Sympathetic Efferent Activity ◽  
Stimulation Of

The sympathetic nervous system is essential for the cardiovascular responses to stimulation of visceral afferents. It remains unclear how the reflex-evoked sympathetic output is distributed to different vascular beds to initiate the hemodynamic changes. In the present study, we examined changes in regional sympathetic nerve activity and blood flows in anesthetized cats. Cardiovascular reflexes were induced by either electrical stimulation of the right splanchnic nerve or application of 10 μg/ml of bradykinin to the gallbladder. Blood flows were measured using colored microspheres or the Transonic flow meter system. Sympathetic efferent activity was recorded from the left splanchnic, inferior cardiac, and tibial nerves. Stimulation of visceral afferents decreased significantly blood flows in the celiac (from 49 ± 4 to 25 ± 3 ml/min) and superior mesenteric (from 35 ± 4 to 23 ± 2 ml/min) arteries, and the vascular resistance in the splanchnic bed was profoundly increased. Consistently, stimulation of visceral afferents decreased tissue blood flows in the splanchnic organs. By contrast, activation of visceral afferents increased significantly blood flows in the coronary artery and portal vein but did not alter the vascular resistance of the femoral artery. Furthermore, stimulation of visceral afferents increased significantly sympathetic efferent activity in the splanchnic (182 ± 44%) but not in the inferior cardiac and tibial nerves. Therefore, this study provides substantial new evidence that stimulation of abdominal visceral afferents differentially induces sympathetic outflow to the splanchnic vascular bed.

Effects of bradykinin and capsaicin on endings of afferent fibers from abdominal visceral organs

1984 ◽  
Vol 247 (3) ◽  
pp. R552-R559 ◽  
Author(s):  
J. C. Longhurst ◽  
M. P. Kaufman ◽  
G. A. Ordway ◽  
T. I. Musch
Keyword(s):  
Afferent Fiber ◽  
Cardiovascular Responses ◽  
Splanchnic Nerve ◽  
Fiber Types ◽  
Afferent Pathways ◽  
Visceral Organs ◽  
C Fibers ◽  
C Fiber ◽  
The Right ◽  
Stimulation Of

Stimulation of sensory endings in abdominal visceral organs with capsaicin or bradykinin reflexly increases heart rate, blood pressure, and myocardial contractility through afferent pathways in splanchnic nerves. To determine the afferent fiber types stimulated, we recorded impulses in the right splanchnic nerve in 12 anesthetized cats after either injecting capsaicin (50-200 micrograms) or bradykinin (6.5-20 micrograms) into the descending thoracic aorta or applying pledgets soaked with these chemicals to a visceral organ. We studied 26 A- and 23 C-fibers, each with one receptive field in the mesentery, stomach, duodenum, jejunum, ileum, pancreas, liver, gallbladder, or porta hepatis. Endings of C-fibers generally were mechanically insensitive, whereas endings of A-fibers were mechanically sensitive. After a latency of 10.7 +/- 3.3 s, capsaicin increased the activity of 10 of 26 A-fibers from 2.0 +/- 0.9 to 9.9 +/- 2.6 impulses/s and 23 of 23 C-fibers from 0.2 +/- 0.1 to 13.0 +/- 1.6 impulses/s after a latency of 3.3 +/- 0.9 s. Bradykinin increased the activity of 15 of 26 A-fibers from 2.6 +/- 0.9 to 7.4 +/- 1.5 impulses/s after a latency of 17.0 +/- 1.7 s and 16 of 22 C-fibers from 0.4 +/- 0.2 to 4.7 +/- 1.2 impulses/s after a latency of 19.0 +/- 1.9 s. Capsaicin stimulated significantly more C- than A-fibers (P less than 0.001) and a significantly greater fraction of C-fibers than did bradykinin (P less than 0.007). We conclude that stimulation of splanchnic C-fiber afferents by capsaicin and both A- and C-fiber afferents by bradykinin is primarily responsible for the reflex cardiovascular responses caused by these chemicals.

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.

scholarly journals Stimulation of the right entorhinal white matter enhances visual memory encoding in humans

2021 ◽  
Vol 14 (1) ◽  
pp. 131-140
Author(s):  
Emily A. Mankin ◽  
Zahra M. Aghajan ◽  
Peter Schuette ◽  
Michelle E. Tran ◽  
Natalia Tchemodanov ◽  
...  
Keyword(s):  
White Matter ◽  
Visual Memory ◽  
Memory Encoding ◽  
The Right ◽  
Stimulation Of

scholarly journals STUDIES WITH THE ELECTROCARDIOGRAPH ON THE ACTION OF THE VAGUS NERVE ON THE HUMAN HEART

1911 ◽  
Vol 14 (3) ◽  
pp. 217-234 ◽  
Author(s):  
G. Canby Robinson ◽  
George Draper
Keyword(s):  
Vagus Nerve ◽  
Mechanical Stimulation ◽  
Human Heart ◽  
Appreciable Effect ◽  
Vagus Stimulation ◽  
Ventricular Systole ◽  
Constant Change ◽  
The Right ◽  
Stimulation Of

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.

scholarly journals Normalization in human somatosensory cortex

2015 ◽  
Vol 114 (5) ◽  
pp. 2588-2599 ◽  
Author(s):  
Gijs Joost Brouwer ◽  
Vanessa Arnedo ◽  
Shani Offen ◽  
David J. Heeger ◽  
Arthur C. Grant
Keyword(s):  
Somatosensory Cortex ◽  
Middle Finger ◽  
Functional Magnetic Resonance ◽  
Stimulus Amplitude ◽  
Target Digit ◽  
Divisive Normalization ◽  
Postcentral Gyrus ◽  
Baseline Response ◽  
The Right ◽  
Stimulation Of

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.

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