scholarly journals Responses of neurons in the caudal medullary lateral tegmental field to visceral inputs and vestibular stimulation in vertical planes

2012 ◽  
Vol 303 (9) ◽  
pp. R929-R940 ◽  
Author(s):  
Jennifer D. Moy ◽  
Daniel J. Miller ◽  
Michael F. Catanzaro ◽  
Bret M. Boyle ◽  
Sarah W. Ogburn ◽  
...  

The dorsolateral reticular formation of the caudal medulla, or the lateral tegmental field (LTF), has been classified as the brain's “vomiting center”, as well as an important region in regulating sympathetic outflow. We examined the responses of LTF neurons in cats to rotations of the body that activate vestibular receptors, as well as to stimulation of baroreceptors (through mechanical stretch of the carotid sinus) and gastrointestinal receptors (through the intragastric administration of the emetic compound copper sulfate). Approximately half of the LTF neurons exhibited graviceptive responses to vestibular stimulation, similar to primary afferents innervating otolith organs. The other half of the neurons had complex responses, including spatiotemporal convergence behavior, suggesting that they received convergent inputs from a variety of vestibular receptors. Neurons that received gastrointestinal and baroreceptor inputs had similar complex responses to vestibular stimulation; such responses are expected for neurons that contribute to the generation of motion sickness. LTF units with convergent baroreceptor and vestibular inputs may participate in producing the cardiovascular system components of motion sickness, such as the changes in skin blood flow that result in pallor. The administration of copper sulfate often modulated the gain of responses of LTF neurons to vestibular stimulation, particularly for units whose spontaneous firing rate was altered by infusion of drug (median of 459%). The present results raise the prospect that emetic signals from the gastrointestinal tract modify the processing of vestibular inputs by LTF neurons, thereby affecting the probability that vomiting will occur as a consequence of motion sickness.


2011 ◽  
Vol 301 (5) ◽  
pp. R1380-R1390 ◽  
Author(s):  
Yoichiro Sugiyama ◽  
Takeshi Suzuki ◽  
Vincent J. DeStefino ◽  
Bill J. Yates

Anatomical studies have demonstrated that the vestibular nuclei project to nucleus tractus solitarius (NTS), but little is known about the effects of vestibular inputs on NTS neuronal activity. Furthermore, lesions of NTS abolish vomiting elicited by a variety of different triggering mechanisms, including vestibular stimulation, suggesting that emetic inputs may converge on the same NTS neurons. As such, an emetic stimulus that activates gastrointestinal (GI) receptors could alter the responses of NTS neurons to vestibular inputs. In the present study, we examined in decerebrate cats the responses of NTS neurons to rotations of the body in vertical planes before and after the intragastric administration of the emetic compound copper sulfate. The activity of more than one-third of NTS neurons was modulated by vertical vestibular stimulation, with most of the responsive cells having their firing rate altered by rotations in the head-up or head-down directions. These responses were aligned with head position in space, as opposed to the velocity of head movements. The activity of NTS neurons with baroreceptor, pulmonary, and GI inputs could be modulated by vertical plane rotations. However, injection of copper sulfate into the stomach did not alter the responses to vestibular stimulation of NTS neurons that received GI inputs, suggesting that the stimuli did not have additive effects. These findings show that the detection and processing of visceral inputs by NTS neurons can be altered in accordance with the direction of ongoing movements.



2019 ◽  
Vol 121 (3) ◽  
pp. 973-982 ◽  
Author(s):  
Bernard Cohen ◽  
Mingjia Dai ◽  
Sergei B. Yakushin ◽  
Catherine Cho

Although motion of the head and body has been suspected or known as the provocative cause for the production of motion sickness for centuries, it is only within the last 20 yr that the source of the signal generating motion sickness and its neural basis has been firmly established. Here, we briefly review the source of the conflicts that cause the body to generate the autonomic signs and symptoms that constitute motion sickness and provide a summary of the experimental data that have led to an understanding of how motion sickness is generated and can be controlled. Activity and structures that produce motion sickness include vestibular input through the semicircular canals, the otolith organs, and the velocity storage integrator in the vestibular nuclei. Velocity storage is produced through activity of vestibular-only (VO) neurons under control of neural structures in the nodulus of the vestibulo-cerebellum. Separate groups of nodular neurons sense orientation to gravity, roll/tilt, and translation, which provide strong inhibitory control of the VO neurons. Additionally, there are acetylcholinergic projections from the nodulus to the stomach, which along with other serotonergic inputs from the vestibular nuclei, could induce nausea and vomiting. Major inhibition is produced by the GABAB receptors, which modulate and suppress activity in the velocity storage integrator. Ingestion of the GABAB agonist baclofen causes suppression of motion sickness. Hopefully, a better understanding of the source of sensory conflict will lead to better ways to avoid and treat the autonomic signs and symptoms that constitute the syndrome.



2021 ◽  
pp. 004051752110191
Author(s):  
Hiroyuki Kanai ◽  
Kentaro Ogawa ◽  
Tetsu Sasagawa ◽  
Kiyohiro Shibata

The stretch property of fabrics is one of the most important factors that provide comfort to wearers. It is expected that tension building up in the fabric can be relaxed and the garment pressure on the body can be reduced by appropriately exploiting its stretch property. Currently, the stretch property is predominantly realized using spandex. However, weaving or knitting elastic threads cannot be employed for the worsted fabric used to design men’s suits because of their effects on the mechanical properties of the fabric (e.g., embrittlement), which deteriorate with time. In this study, worsted fabric with a graded mechanical stretch property was produced, and the effect of the mechanical stretch property on comfort was verified. The mechanical stretch property is developed from the tension relaxation and fabric shrinkage along the weft yarn during the crabbing, scouring, and drying stages of the finishing process. Then, the form of the fabric is set by heating. In this study, the worsted fabric had an elongation ratio varying from 5.9% to 16.1% along the weft direction that was produced without using elastic thread. Furthermore, men’s suit pants were made from the fabrics. The effect of the stretch property on the garment comfort was verified through sensory evaluation and garment pressure measurement. The contribution of the mechanical stretch property in improving the garment comfort of men’s suit pants is discussed.



2016 ◽  
Vol 116 (4) ◽  
pp. 1586-1591 ◽  
Author(s):  
Joanne Wang ◽  
Richard F. Lewis

Migraine is associated with enhanced motion sickness susceptibility and can cause episodic vertigo [vestibular migraine (VM)], but the mechanisms relating migraine to these vestibular symptoms remain uncertain. We tested the hypothesis that the central integration of rotational cues (from the semicircular canals) and gravitational cues (from the otolith organs) is abnormal in migraine patients. A postrotational tilt paradigm generated a conflict between canal cues (which indicate the head is rotating) and otolith cues (which indicate the head is tilted and stationary), and eye movements were measured to quantify two behaviors that are thought to minimize this conflict: suppression and reorientation of the central angular velocity signal, evidenced by attenuation (“dumping”) of the vestibuloocular reflex and shifting of the rotational axis of the vestibuloocular reflex toward the earth vertical. We found that normal and migraine subjects, but not VM patients, displayed an inverse correlation between the extent of dumping and the size of the axis shift such that the net “conflict resolution” mediated through these two mechanisms approached an optimal value and that the residual sensory conflict in VM patients (but not migraine or normal subjects) correlated with motion sickness susceptibility. Our findings suggest that the brain normally controls the dynamic and spatial characteristics of central vestibular signals to minimize intravestibular sensory conflict and that this process is disrupted in VM, which may be responsible for the enhance motion intolerance and episodic vertigo that characterize this disorder.



2004 ◽  
Vol 96 (6) ◽  
pp. 2301-2316 ◽  
Author(s):  
Richard C. Fitzpatrick ◽  
Brian L. Day

Galvanic vestibular stimulation (GVS) is a simple, safe, and specific way to elicit vestibular reflexes. Yet, despite a long history, it has only recently found popularity as a research tool and is rarely used clinically. The obstacle to advancing and exploiting GVS is that we cannot interpret the evoked responses with certainty because we do not understand how the stimulus acts as an input to the system. This paper examines the electrophysiology and anatomy of the vestibular organs and the effects of GVS on human balance control and develops a model that explains the observed balance responses. These responses are large and highly organized over all body segments and adapt to postural and balance requirements. To achieve this, neurons in the vestibular nuclei receive convergent signals from all vestibular receptors and somatosensory and cortical inputs. GVS sway responses are affected by other sources of information about balance but can appear as the sum of otolithic and semicircular canal responses. Electrophysiological studies showing similar activation of primary afferents from the otolith organs and canals and their convergence in the vestibular nuclei support this. On the basis of the morphology of the cristae and the alignment of the semicircular canals in the skull, rotational vectors calculated for every mode of GVS agree with the observed sway. However, vector summation of signals from all utricular afferents does not explain the observed sway. Thus we propose the hypothesis that the otolithic component of the balance response originates from only the pars medialis of the utricular macula.



2021 ◽  
Vol 23 (103) ◽  
pp. 109-115
Author(s):  
L.-M. Kostyshyn ◽  
R. Sachuk ◽  
Ye. Kostyshyn ◽  
O. Katsaraba

Suspension for injection “Amoxidev 15” is prescribed to fur-bearing animals (mink, fox), dogs and cats for the treatment of respiratory diseases (tonsillitis, tracheitis, pneumonia, bronchitis, rhinitis, sinusitis, bronchopneumonia), digestive (gastritis, enteritis, enteritis). genitourinary systems (nephritis, urethritis, urocystitis, mastitis, metritis, agalactia), musculoskeletal system (arthritis, osteoarthritis, joint injuries, tendonitis, hoof lesions), skin and soft tissues (eczema, dermatitis) caused by sensitive drug by microorganisms, including colibacillosis, streptococcus, bronchopneumonia, etc. Toxicological evaluation of the veterinary drug “Amoxidev 15” under the conditions of acute and subacute toxicological experiments on a model of white rats. According to the results of an acute toxicological experiment with intragastric administration of the drug “Amoxidev 15” white rats DL50 could not be calculated because the death of laboratory animals was not detected within 14 days after administration. The maximum administered dose (in absolute weight of the drug) was 20000.0 mg/kg body weight, which allows to refer the drug to class VI toxicity of relatively harmless substances (DL50 > 15000 mg/kg body weight), and the degree of safety to class IV – low-hazard substances (DL50 > 5000 mg/kg). According to the results of an acute toxicological experiment with subcutaneous administration of the drug “Amoxidev 15” white rats DL50 could not be calculated because the death of laboratory animals was not detected within 14 days after administration, the maximum dose was 5000.0 mg/kg body weight, therefore, the drug “Amoxidev 15” when administered subcutaneously by toxicity can be classified as class VI substances relatively harmless (DL50 Subcut > 4500.0 mg/kg). When administered subcutaneously to white rats, the drug “Amoxidev 15” under conditions of subacute toxicological experiment in doses of 0.1–1.0 ml/kg does not cause hemo-, hepato- and nephrotoxic effects on the body of laboratory animals, although 3-day administration of the drug in a dose 1.0 ml/kg body weight caused an increase in the activity of hepatospecific enzymes ALT and AST by 12.5 and 11.1 % (P < 0.05), respectively, relative to the control, which was restored to the control level 7 days after cessation.



Author(s):  
А. М. Романюк ◽  
Г. Ю Будко

ОСОБЛИВОСТІ МАСОМЕТРИЧНИХ ПОКАЗНИКІВ ТА МОРФОЛОГІЧНИХ ЗМІН ГОЛОВНОГО МОЗКУ СТАТЕВОЗРІЛИХ ЩУРІВ В УМОВАХ ВПЛИВУ НА ОРГАНІЗМ СУЛЬФАТІВ МІДІ, ЦИНКУ ТА ЗАЛІЗА - З метою вивчення масометричних показників щурів та їх головного мозку за умов довготривалої дії (упродовж 90 діб) на організм сульфатів міді, цинку та заліза було проведено експеримент на 48 білих статевозрілих щурах-самцях масою 200-250 г віком 5-7 місяців. Застосовували анатомічні, статистичні та загальноприйняті методики мікроанатомічного методу дослідження. Встановлено, що комбінований вплив на організм сульфатів міді цинку та заліза чинить на головний мозок досить виражений токсичний ефект, що негативно позначається на масометричних показниках загальної маси щурів та маси головного мозку. Це свідчить про розвиток у головному мозку явищ гострого набряку з ознаками геморагічної інфільтрації. Ступінь вираження набряку зростає та досягає максимальних показників наприкінці експерименту.<br />ОСОБЕННОСТИ МАСОМЕТРИЧЕСКИХ ПОКАЗАТЕЛЕЙ И МОРФОЛОГИЧЕСКИХ ИЗМЕНЕНИЙ ГОЛОВНОГО МОЗГА ПОЛОВОЗРЕЛЫХ КРЫС В УСЛОВИЯХ ВОЗДЕЙСТВИЯ НА ОРГАНИЗМ СУЛЬФАТОВ МЕДИ, ЦИНКА И ЖЕЛЕЗА - С целью изучения масометрических показателей крыс и их головного мозга в условиях длительного действия (в течение 90 суток) на организм сульфатов меди, цинка и железа был проведен эксперимент на 48 белых половозрелых крысах-самцах массой 200250 г в возрасте 5-7 месяцев. Применялись анатомические, статистические и общепринятые методики микроанатомического метода исследования. Установлено, что комбинированное воздействие на организм сульфатов меди и цинка и железа оказывает на мозг достаточно выразительный токсический эффект, что отрицательно сказывается на массометрических показателях общего веса крыс и веса головного мозга. Это свидетельствует о развитии в головном мозге явлений острого отека с признаками геморрагической инфильтрации, степень выраженности которого максимальна в конце эксперимента.<br />FEATURES OF MASS INDICES AND MORPHOLOGICAL CHANGES IN ADULT RAT BRAIN UNDER THE INFLUENCE ON THE BODY OF COPPER SULFATE, ZINC AND IRON - To study the performance of rats and their mass brain in long acting (for 90 days) on the body of copper sulfate, zinc and iron, an experiment was conducted on 48 white adult male rats weighing 200-250 gram, aged 5-7 months. There was applied anatomy, statistics and conventional techniques microanatomical research method. It was established that the combined effect on the body of copper and zinc sulphates and iron in the brain has enough expressive toxicity, which affects performance on the total weight of the rats and brain weight. This testifies to the development of brain edema, acute phenomena with signs of hemorrhagic infiltration. The severity of edema increases and reaches maximum performance at the end of the experiment.<br />Ключові слова: головний мозок, солі важких металів, відносна маса, коефіцієнт цефалізації.<br />Ключевые слова: головной мозг, соли тяжелых металлов, относительная масса, коэффициент цефа- лизации.<br />Key words: brain, salts of heavy metals, relative mass, ratio cephalization.



2019 ◽  
Vol 104 (11) ◽  
pp. 1622-1629 ◽  
Author(s):  
Anadil Javaid ◽  
Houda Chouhna ◽  
Ben Varghese ◽  
Elie Hammam ◽  
Vaughan G. Macefield


1956 ◽  
Vol 185 (3) ◽  
pp. 617-623 ◽  
Author(s):  
S. C. Wang ◽  
Herman I. Chinn

Motion sickness was experimentally induced in dogs by means of a standardized swinging exposure. Susceptible dogs were selected for surgical extirpation of the labyrinths or various parts of the cerebellum. It was found that animals showed no vomiting responses to long exposures of swinging motion after bilateral labyrinthectomy or ablation of the nodulus and uvula. Even with incomplete extirpation of these structures, animals would become partially or totally resistant to motion sickness. In general, these operated animals exhibited normal responses to intravenously administered apomorphine or orally administered copper sulfate. These results indicate that motion stimulates the labyrinthine receptors, and the vestibular impulses traverse the nodulus and uvula of the cerebellum, and the chemoceptive emetic trigger zone, and finally reach the medullary vomiting center.



2017 ◽  
Vol 118 (1) ◽  
pp. 84-92 ◽  
Author(s):  
Johannes Keyser ◽  
W. Pieter Medendorp ◽  
Luc P. J. Selen

When reaching for an earth-fixed object during self-rotation, the motor system should appropriately integrate vestibular signals and sensory predictions to compensate for the intervening motion and its induced inertial forces. While it is well established that this integration occurs rapidly, it is unknown whether vestibular feedback is specifically processed dependent on the behavioral goal. Here, we studied whether vestibular signals evoke fixed responses with the aim to preserve the hand trajectory in space or are processed more flexibly, correcting trajectories only in task-relevant spatial dimensions. We used galvanic vestibular stimulation to perturb reaching movements toward a narrow or a wide target. Results show that the same vestibular stimulation led to smaller trajectory corrections to the wide than the narrow target. We interpret this reduced compensation as a task-dependent modulation of vestibular feedback responses, tuned to minimally intervene with the task-irrelevant dimension of the reach. These task-dependent vestibular feedback corrections are in accordance with a central prediction of optimal feedback control theory and mirror the sophistication seen in feedback responses to mechanical and visual perturbations of the upper limb. NEW & NOTEWORTHY Correcting limb movements for external perturbations is a hallmark of flexible sensorimotor behavior. While visual and mechanical perturbations are corrected in a task-dependent manner, it is unclear whether a vestibular perturbation, naturally arising when the body moves, is selectively processed in reach control. We show, using galvanic vestibular stimulation, that reach corrections to vestibular perturbations are task dependent, consistent with a prediction of optimal feedback control theory.



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