Changes in outflow to respiratory pump muscles produced by natural vestibular stimulation

1996 ◽  
Vol 76 (5) ◽  
pp. 3274-3284 ◽  
Author(s):  
C. D. Rossiter ◽  
N. L. Hayden ◽  
S. D. Stocker ◽  
B. J. Yates
Keyword(s):  
Phrenic Nerve ◽  
Upper Airway ◽  
Head Rotation ◽  
Vestibular Nuclei ◽  
Vestibular Stimulation ◽  
Vagus Nerves ◽  
Stimulus Position ◽  
Nerve Activity ◽  
Static Head ◽  
Head Rotations

1. Activity was recorded from abdominal (expiratory) and phrenic (inspiratory) nerves during natural vestibular stimulation in multiple vertical planes and the horizontal plane in decerebrate cats. Vestibular stimulation was produced by rotating the head in animals whose upper cervical dorsal roots were transected to remove inputs from neck receptors; the upper airway and carotid sinus were denervated, and the vagus nerves were transected to assure that the head rotations did not elicit visceral or pulmonary inputs. 2. The plane of head rotation that produced maximal modulation of respiratory nerve activity (response vector orientation) was measured at one or more frequencies between 0.05 and 0.5 Hz. The dynamics of the response were then studied with sinusoidal (0.05–2 Hz) stimuli aligned with this orientation. In some animals, sinusoidal horizontal rotations of the head at 0.5 and 1 Hz or static head tilts in the pitch and roll planes were also delivered. 3. Typically, maximal modulation of abdominal nerve outflow was elicited by head rotations in a plane near pitch; nose-up rotations produced increased outflow, and nose-down rotations reduced nerve discharges. The gains of the responses (relative to stimulus position) remained relatively constant across stimulus frequencies, and the phases were consistently near stimulus position, like regularly firing otolith afferents. Static nose-up tilt produced elevated abdominal nerve activity throughout the stimulus period, providing further evidence that pitch-sensitive otolith receptors contribute to the response. Horizontal head rotations had little influence on abdominal nerve discharges. 4. The abdominal nerve responses to head rotation were abolished by chemical or aspiration lesions of the medial and inferior vestibular nuclei, which is concordant with the responses resulting from activation of vestibular receptors. Transections of axons arising from bulbospinal neurons in the ventral respiratory group, which are known to be the predominant source of expiratory signals to the spinal cord, reduced but did not abolish the vestibuloabdominal reflex. Thus it is likely that nonrespiratory neurons also participate in generating this response. 5. Nose-up pitch of the head; and in particular large (50 degrees) static tilts, produced small increases in phrenic nerve activity. Ear-down tilt and horizontal rotation of the head produced no responses in the phrenic nerve. 6. The existence of vestibular inputs to some respiratory motoneurons suggests that the vestibular system has influences on muscles in addition to those typically considered to have antigravity roles, and participates globally in adjusting muscle activity during movement and changes in posturex.

Tilt responses of neurons in the caudal descending nucleus of the decerebrate cat: influence of the caudal cerebellar vermis and of neck receptors

1996 ◽  
Vol 75 (3) ◽  
pp. 1242-1249 ◽  
Author(s):  
V. J. Wilson ◽  
H. Ikegami ◽  
R. H. Schor ◽  
D. B. Thomson
Keyword(s):  
Head Rotation ◽  
Muscle Spindles ◽  
Vestibular Nuclei ◽  
Vestibular Stimulation ◽  
Cerebellar Vermis ◽  
Neck Muscle ◽  
Vestibular Input ◽  
Decerebrate Cat ◽  
Neck Rotation ◽  
Vertical Semicircular Canal

1. In decerebrate cats with intact cerebellums, we studied the responses of neurons in the caudal areas of the vestibular nuclei to natural vestibular stimulation in vertical planes and to neck rotation. The activity of most neurons was recorded in the caudal half of the descending nucleus. 2. One goal of our experiments was to compare the dynamic and spatial properties of responses to sinusoidal vestibular stimulation with those seen in previous experiments in which the caudal cerebellar vermis, including the nodulus and uvula, was removed. This part of the cerebellum receives vestibular input and projects to the caudal areas of the vestibular nuclei, suggesting that it could influence responses to stimulation of the labyrinth. 3. As in our previous experiments, most neurons could be classified as receiving predominant input either from the otoliths or from one vertical semicircular canal. When mean gain and phase and response vector orientations were compared, there were no obvious differences between the behavior of neurons in the partially decerebellate preparation and the one with the cerebellum intact, demonstrating that in the decerebrate cat the nodulus and uvula have little or no influence on the processing of vertical vestibular input in this region of the vestibular nuclei. 4. Only 23 of 74 (31%) of neurons tested responded to neck rotation. This contrasts with the much larger fractions that respond to this stimulus in Deiters' nucleus and in the rostral descending nucleus. We also recorded from neurons near the vestibular nuclei, mainly in the external cuneate nucleus. All of them (9 of 9) responded to neck rotation. 5. Responses to neck rotation also differed in their dynamics from those found more rostrally in the vestibular nuclei. Dynamics of more rostral neurons resemble those of neck muscle spindles, as do those of external cuneate neurons. The dynamics of caudal vestibular neurons, on the other hand, have a steeper gain slope and more advanced phases than do those of neurons in the more rostral vestibular nuclei. This suggests the possibility of involvement of additional receptors in the production of these responses. 6. In the more rostral vestibular nuclei, responses to vestibular and neck rotation are most often antagonistic, so that head rotation results in little or no response. This is not the case in the caudal areas of the vestibular nuclei, where less than half the neurons tested displayed antagonistic behavior. Further experiments are required to put the neck projection to the caudal vestibular nuclei in a functional context.

Sympathetic nerve activity during natural stimulation of horizontal semicircular canals in humans

1998 ◽  
Vol 275 (4) ◽  
pp. R1274-R1278 ◽  
Author(s):  
Chester A. Ray ◽  
Keith M. Hume ◽  
Samuel L. Steele
Keyword(s):  
Sympathetic Nerve ◽  
Sympathetic Nerve Activity ◽  
Semicircular Canals ◽  
Head Rotation ◽  
Otolith Organs ◽  
Nerve Activity ◽  
Natural Stimulation ◽  
Vascular Beds ◽  
Static Head ◽  
Stimulation Of

We have shown that static head-down neck flexion elicits increases in muscle (MSNA) but not skin sympathetic nerve activity (SSNA) in humans. These findings suggest that stimulation of the otolith organs causes differential sympathetic outflow to vascular beds. The purpose of the present study was to determine whether yaw head rotation (YHR), which stimulates the horizontal semicircular canals, elicits sympathetic nerve responses. To test this question, we recorded MSNA ( n = 33) and SSNA ( n = 25) before and during 3 min of sinusoidal YHR performed at 0.1, 0.6, and 1.0 Hz. At all frequencies, YHR elicited no significant changes in heart rate and mean arterial pressure. Likewise, YHR did not significantly change either MSNA or SSNA at all frequencies. Our results indicate that stimulation of the horizontal semicircular canals by YHR does not alter SNA to either muscle or skin. Moreover, these results provide evidence to support the concept that the otolith organs but not the horizontal semicircular canals participate in the regulation of SNA in humans.

Properties of sympathetic reflexes elicited by natural vestibular stimulation: implications for cardiovascular control

1994 ◽  
Vol 71 (6) ◽  
pp. 2087-2092 ◽  
Author(s):  
B. J. Yates ◽  
A. D. Miller
Keyword(s):  
Head Rotation ◽  
Splanchnic Nerve ◽  
Vestibular Nuclei ◽  
Vestibular Stimulation ◽  
Similar Response ◽  
Response Dynamics ◽  
Upper Cervical ◽  
Sympathetic Reflexes ◽  
Vector Orientation ◽  
Vestibulosympathetic Reflexes

1. To study the properties of vestibulosympathetic reflexes we recorded outflow from the splanchnic nerve during natural vestibular stimulation in multiple vertical planes in decerebrate cats. Most of the animals were cerebellectomized, although some responses were recorded in cerebellum-intact preparations. Vestibular stimulation was produced by rotating the head in animals whose upper cervical dorsal roots were transected to remove inputs from neck receptors; a baroreceptor denervation and vagotomy were also performed to remove visceral inputs. 2. The plane of head rotation that produced maximal modulation of splanchnic nerve activity (response vector orientation) was measured at 0.2–0.5 Hz. The dynamics of the response were then studied with sinusoidal (0.05- to 1-Hz) stimuli aligned with this orientation. 3. Typically, maximal modulation of splanchnic nerve outflow was elicited by head rotations in a plane near pitch; nose-up rotations produced increased outflow and nose-down rotations reduced nerve discharges. The gains of the responses remained relatively constant across stimulus frequencies and the phases were consistently near stimulus position, like regularly firing otolith afferents. Similar response dynamics were recorded in cerebellectomized and cerebellum-intact animals. 4. The splanchnic nerve responses to head rotation could be abolished by microinjections of the excitotoxin kainic acid into the medial and inferior vestibular nuclei, which is concordant with the responses resulting from activation of vestibular receptors. 5. The properties fo vestibulosympathetic reflexes recorded from the splanchnic nerve support the hypothesis that the vestibular system participates in compensating for posturally related changes in blood pressure.

scholarly journals Sympathetic responses to head-down rotations in humans

1999 ◽  
Vol 86 (6) ◽  
pp. 1971-1976 ◽  
Author(s):  
Keith M. Hume ◽  
Chester A. Ray
Keyword(s):  
Sympathetic Nerve Activity ◽  
Muscle Sympathetic Nerve Activity ◽  
Vertical Axis ◽  
Neck Flexion ◽  
Nerve Activity ◽  
Neck Extension ◽  
Arterial Blood ◽  
Static Head ◽  
Head Positions ◽  
Head Rotations

Muscle sympathetic nerve activity (MSNA) increases with head-down neck flexion (HDNF). The present study had three aims: 1) to examine sympathetic and vascular responses to two different magnitudes of HDNF; 2) to examine these same responses during prolonged HDNF; and 3) to determine the influence of nonspecific pressure receptors in the head on MSNA. The first experiment tested responses to two static head positions in the vertical axis [HDNF and intermediate HDNF (I-HDNF; ∼50% of HDNF)]. MSNA increased above baseline during both I-HDNF and HDNF (from 219 ± 36 to 301 ± 47 and from 238 ± 42 to 356 ± 59 units/min, respectively; P < 0.01). Calf blood flow (CBF) decreased and calf vascular resistance increased during both I-HDNF and HDNF ( P < 0.01). Both the increase in MSNA and the decrease in CBF were linearly related to the magnitude of the downward head rotations ( P < 0.01). The second experiment tested responses during prolonged HDNF. MSNA increased (from 223 ± 63 to 315 ± 79 units/min; P < 0.01) and CBF decreased (from 3.2 ± 0.4 to 2.6 ± 0.04 ml ⋅ 100 ml−1 ⋅ min−1; P < 0.01) at the onset of HDNF. These responses were maintained throughout the 30-min period. Mean arterial blood pressure gradually increased during the 30 min of HDNF (from 94 ± 4 to 105 ± 3 mmHg; P < 0.01). In a third experiment, head-down neck extension was performed with subjects in the supine position. Unlike HDNF, head-down neck extension did not affect MSNA. The results from these studies demonstrate that MSNA: 1) increases in magnitude as the degree of HDNF increases; 2) remains elevated above baseline during prolonged HDNF; and 3) responses during HDNF are not associated with nonspecific receptors in the head activated by increases in cerebral pressure.

Inhibition of inspiratory upper airway motoneuron activity by phasic volume feedback

1986 ◽  
Vol 60 (4) ◽  
pp. 1373-1379 ◽  
Author(s):  
S. T. Kuna
Keyword(s):  
Phrenic Nerve ◽  
Differential Effect ◽  
Critical Role ◽  
Upper Airway ◽  
Nerve Activity ◽  
Airway Patency ◽  
Efferent Activity ◽  
Phrenic Nerve Activity ◽  
Neural Activities ◽  
Motoneuron Activity

The effects of phasic volume feedback on efferent hypoglossal, recurrent laryngeal and phrenic nerve activity were studied in decerebrate, paralyzed intubated cats ventilated with a phrenic-driven servo-respirator. The gain of the respirator was altered for single inspirations, and the resulting changes in neural activities were quantified by comparison with respective neural activities without phasic volume feedback. The volume thresholds for suppression of hypoglossal and recurrent laryngeal activities were time independent. Above these two thresholds and extending over a substantial range, volume feedback caused graded inhibition of upper airway motoneuron outputs. At any particular time during inspiration the relationships between hypoglossal or recurrent laryngeal inhibition and volume were concave to the volume axis. Rate of airflow appeared to exert an effect on upper airway motoneuron activity independent of volume. These results indicate that for hypoglossal and recurrent laryngeal efferent activity 1) volume feedback can cause a sustained graded inhibition throughout inspiration; 2) the volume thresholds are time independent; and 3) partial inhibition decreases susceptibility to additional inhibition. These actions of volume feedback on upper airway motoneuron output differ from those on phrenic efferent discharge and show that phasic vagal volume feedback has a marked and differential effect on upper airway motoneuron activity. The vagus, in this preparation, appears to play a critical role in the regulation of upper airway motoneuron activity and therefore maintenance of upper airway patency.

Effect of chemical stimuli on nerves supplying upper airway muscles

1982 ◽  
Vol 52 (3) ◽  
pp. 530-536 ◽  
Author(s):  
D. Weiner ◽  
J. Mitra ◽  
J. Salamone ◽  
N. S. Cherniack
Keyword(s):  
Recurrent Laryngeal Nerve ◽  
Phrenic Nerve ◽  
Hypoglossal Nerve ◽  
Cranial Nerves ◽  
Upper Airway ◽  
Laryngeal Nerve ◽  
Nerve Activity ◽  
Phrenic Nerve Activity ◽  
Chemical Stimuli ◽  
Upper Airway Muscles

Studies of upper airway resistance suggest that the activity of cranial nerves supplying upper airway muscles changes with chemical drive and that imbalances in the activation of these nerves as compared to the phrenic play a role in causing upper airway obstruction. We assessed the effect of hypoxia and hypercapnia on the activity of the hypoglossal nerve, the recurrent laryngeal nerve, and phrenic nerve in paralyzed anesthetized artificially ventilated dogs. Comparison of hypoglossal and phrenic nerves were also repeated after vagotomy. Both hypoglossal and recurrent laryngeal nerves exhibited increased activity with inspiration. Hypoxia and hypercapnia increased phrenic nerve activity as well as the activity of the two cranial nerves. While linear increases occurred in phrenic and recurrent laryngeal nerve activity with both chemical stimuli, the relationship between hypoglossal and phrenic nerve activity was curvilinear. At lower levels of chemical drive, changes in hypoglossal nerve were less than in the phrenic, and the reverse was true at higher levels of chemical stimulation. There were also differences in the response of both cranial nerves and the phrenic to changing vagal stimulation. The dissimilarities observed in the cranial response of the nerves (versus the phrenic) could potentially affect the forces developed during inspiration and lead to obstruction in the upper airway.

scholarly journals Effects of caloric vestibular stimulation on serotoninergic system in the media vestibular nuclei of guinea pigs

2007 ◽  
Vol 120 (2) ◽  
pp. 120-124 ◽  
Author(s):  
Fu-rong MA ◽  
Jun-xiu LIU ◽  
Xue-pei LI ◽  
Jian-jun MAO ◽  
Qun-dan ZHANG ◽  
...  
Keyword(s):  
Guinea Pigs ◽  
Vestibular Nuclei ◽  
Vestibular Stimulation ◽  
Serotoninergic System ◽  
Caloric Vestibular Stimulation ◽  
The Media

Quantitative assessment of self-treated canalith repositioning procedures using inertial measurement unit sensors

2021 ◽  
pp. 1-9
Author(s):  
Chiheon Kwon ◽  
Yunseo Ku ◽  
Shinhye Seo ◽  
Eunsook Jang ◽  
Hyoun-Joong Kong ◽  
...  
Keyword(s):  
Evaluation Criteria ◽  
Head Rotation ◽  
Large Error ◽  
Head Movements ◽  
The Self ◽  
Measurement Unit ◽  
Success Rates ◽  
Home Based ◽  
Epley Maneuver ◽  
Head Rotations

BACKGROUND: Low success and high recurrence of benign paroxysmal positional vertigo (BPPV) after home-based self-treated Epley and Barbeque (BBQ) roll maneuvers is an important issue. OBJECTIVE: To quantify the cause of low success rate of self-treated Epley and BBQ roll maneuvers and provide a clinically acceptable criterion to guide self-treatment head rotations. METHODS: Twenty-five participants without active BPPV wore a custom head-mount rotation monitoring device for objective measurements. Self-treatment and specialist-assisted maneuvers were compared for head rotation accuracy. Absolute differences between the head rotation evaluation criteria (American Academy of Otolaryngology guidelines) and measured rotation angles were considered as errors. Self-treatment and specialist-treated errors in maneuvers were compared. Between-trial variations and age effects were evaluated. RESULTS: A significantly large error and between-trial variation occurred in step 4 of the self-treated Epley maneuver, with a considerable error in the second trial. The cumulative error of all steps of self-treated BBQ roll maneuver was significantly large. Age effect occurred only in the self-treated BBQ roll maneuver. Errors in specialist-treated maneuvers ranged from 10 to 20 degrees. CONCLUSIONS: Real-time feedback of head movements during simultaneous head-body rotations could increase success rates of self-treatments. Specialist-treated maneuvers can be used as permissible rotation margin criteria.

Entrainment pattern between sympathetic and phrenic nerve activities in the Sprague-Dawley rat: hypoxia-evoked sympathetic activity during expiration

2004 ◽  
Vol 286 (6) ◽  
pp. R1121-R1128 ◽  
Author(s):  
Thomas E. Dick ◽  
Y.-H. Hsieh ◽  
Shaun Morrison ◽  
Sharon K. Coles ◽  
Nanduri Prabhakar
Keyword(s):  
Phrenic Nerve ◽  
Sympathetic Activity ◽  
Respiratory Pattern ◽  
Sprague Dawley ◽  
Short Term ◽  
Nerve Activity ◽  
Term Potentiation ◽  
Motor Activities ◽  
Respiratory Modulation ◽  
Activity Dependent

Sympathetic and respiratory motor activities are entrained centrally. We hypothesize that this coupling may partially underlie changes in sympathetic activity evoked by hypoxia due to activity-dependent changes in the respiratory pattern. Specifically, we tested the hypothesis that sympathetic nerve activity (SNA) expresses a short-term potentiation in activity after hypoxia similar to that expressed in phrenic nerve activity (PNA). Adult male, Sprague-Dawley (Zivic Miller) rats ( n = 19) were anesthetized (Equithesin), vagotomized, paralyzed, ventilated, and pneumothoracotomized. We recorded PNA and splanchnic SNA (sSNA) and generated cycle-triggered averages (CTAs) of rectified and integrated sSNA before, during, and after exposures to hypoxia (8% O2 and 92% N2 for 45 s). Inspiration (I) and expiration (E) were divided in half, and the average and area of integrated sSNA were calculated and compared at the following time points: before hypoxia, at the peak breathing frequency during hypoxia, immediately before the end of hypoxia, immediately after hypoxia, and 60 s after hypoxia. In our animal model, sSNA bursts consistently followed the I-E phase transition. With hypoxia, sSNA increased in both halves of E, but preferentially in the second rather than the first half of E, and decreased in I. After hypoxia, sSNA decreased abruptly, but the coefficient of variation in respiratory modulation of sSNA was significantly less than that at baseline. The hypoxic-evoked changes in sympathetic activity and respiratory pattern resulted in sSNA in the first half of E being correlated negatively to that in the second half of E ( r = −0.65, P < 0.05) and positively to Te ( r = 0.40, P < 0.05). Short-term potentiation in sSNA appeared not as an increase in the magnitude of activity but as an increased consistency of its respiratory modulation. By 60 s after hypoxia, the variability in the entrainment pattern had returned to baseline. The preferential recruitment of late expiratory sSNA during hypoxia results from either activation by expiratory-modulated neurons or by non-modulated neurons whose excitatory drive is not gated during late E.

Probing the human vestibular system with galvanic stimulation

2004 ◽  
Vol 96 (6) ◽  
pp. 2301-2316 ◽  
Author(s):  
Richard C. Fitzpatrick ◽  
Brian L. Day
Keyword(s):  
Balance Control ◽  
Semicircular Canals ◽  
Vestibular Nuclei ◽  
Vestibular Stimulation ◽  
Otolith Organs ◽  
Sources Of Information ◽  
Electrophysiological Studies ◽  
Human Balance ◽  
Cortical Inputs ◽  
Vestibular Organs

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.

Sign in / Sign up

Export Citation Format

Share Document