Vestibular loss disrupts daily rhythm in rats

2015 ◽  
Vol 118 (3) ◽  
pp. 310-318 ◽  
Author(s):  
T. Martin ◽  
B. Mauvieux ◽  
J. Bulla ◽  
G. Quarck ◽  
D. Davenne ◽  
...  
Keyword(s):  
Daily Rhythm ◽  
Control Group ◽  
Vestibular Input ◽  
Daily Rhythms ◽  
Cell Degeneration ◽  
Vestibular Loss ◽  
Anatomical Structures ◽  
Bilateral Vestibular Loss ◽  
Vestibular Lesion ◽  
Vestibular Pathology

Hypergravity disrupts the circadian regulation of temperature (Temp) and locomotor activity (Act) mediated through the vestibular otolithic system in mice. In contrast, we do not know whether the anatomical structures associated with vestibular input are crucial for circadian rhythm regulation at 1 G on Earth. In the present study we observed the effects of bilateral vestibular loss (BVL) on the daily rhythms of Temp and Act in semipigmented rats. Our model of vestibular lesion allowed for selective peripheral hair cell degeneration without any other damage. Rats with BVL exhibited a disruption in their daily rhythms (Temp and Act), which were replaced by a main ultradian period (τ <20 h) for 115.8 ± 68.6 h after vestibular lesion compared with rats in the control group. Daily rhythms of Temp and Act in rats with BVL recovered within 1 wk, probably counterbalanced by photic and other nonphotic time cues. No correlation was found between Temp and Act daily rhythms after vestibular lesion in rats with BVL, suggesting a direct influence of vestibular input on the suprachiasmatic nucleus. Our findings support the hypothesis that the vestibular system has an influence on daily rhythm homeostasis in semipigmented rats on Earth, and raise the question of whether daily rhythms might be altered due to vestibular pathology in humans.

Role of Vestibular Input in Triggering and Modulating Postural Responses in Unilateral and Bilateral Vestibular Loss Patients

2009 ◽  
Vol 14 (2) ◽  
pp. 130-138 ◽  
Author(s):  
F. Mbongo ◽  
C. Qu&rsquo;hen ◽  
P.P. Vidal ◽  
P. Tran Ba Huy ◽  
C. de Waele
Keyword(s):  
Vestibular Input ◽  
Vestibular Loss ◽  
Bilateral Vestibular Loss ◽  
Postural Responses

Bilateral Vestibular Loss Leads to Active Destabilization of Balance During Voluntary Head Turns in the Standing Cat

2006 ◽  
Vol 95 (6) ◽  
pp. 3783-3797 ◽  
Author(s):  
Paul J. Stapley ◽  
Lena H. Ting ◽  
Chen Kuifu ◽  
Dirk G. Everaert ◽  
Jane M. Macpherson
Keyword(s):  
Vertical Axis ◽  
The Body ◽  
Head Turn ◽  
Vestibular Input ◽  
Ipsilateral Side ◽  
Vestibular Loss ◽  
Bilateral Vestibular Loss ◽  
Postural Responses ◽  
Postural Imbalance ◽  
Lateral Head

The purpose of this study was to determine the source of postural instability in labyrinthectomized cats during lateral head turns. Cats were trained to maintain the head in a forward orientation and then perform a rapid, large-amplitude head turn to left or right in yaw, while standing freely on a force platform. Head turns were biomechanically complex with the primary movement in the yaw plane accompanied by an ipsilateral ear-down roll and nose-down pitch. Cats used a strategy of pushing off by activating extensors of the contralateral forelimb while using all four limbs to produce a rotational moment of force about the vertical axis. After bilateral labyrinthectomy, the initial components of the head turn and accompanying postural responses were hypermetric, but otherwise similar to those produced before the lesion. However, near the time of peak yaw velocity, the lesioned cats produced an unexpected burst in extensors of the contralateral limbs that thrust the body to the ipsilateral side, leading to falls. This postural error was in the frontal (roll) plane, even though the primary movement was a rotation in the horizontal (yaw) plane. The response error decreased in amplitude with compensation but did not disappear. We conclude that lack of vestibular input results in active destabilization of balance during voluntary head movement. We postulate that the postural imbalance arises from the misperception that the trunk was rolling contralaterally, based on signals from neck proprioceptors in the absence of vestibular inputs.

Thermal sensitivity of reptilian melatonin rhythms: "cold" tuatara vs. "warm" skink

1989 ◽  
Vol 256 (5) ◽  
pp. R1160-R1163 ◽  
Author(s):  
B. T. Firth ◽  
M. B. Thompson ◽  
D. J. Kennaway ◽  
I. Belan
Keyword(s):  
Environmental Conditions ◽  
Thermal Sensitivity ◽  
Cold Temperature ◽  
Daily Rhythm ◽  
Threshold Temperature ◽  
Daily Rhythms ◽  
Thermoregulatory Behavior ◽  
Lower Amplitude ◽  
Sphenodon Punctatus ◽  
Reptilian Species

Daily rhythms in plasma melatonin levels were compared in two ecologically diverse reptilian species under natural environmental conditions in autumn. The nocturnal, cold temperature-adapted tuatara (Sphenodon punctatus) had a melatonin rhythm of much lower amplitude than did the diurnal desert-adapted sleepy lizard (Tiliqua rugosa). Experiments in controlled laboratory environments showed that, although both species are capable of attaining a comparable melatonin peak (approximately 750 pmol/l), the threshold temperature at which a significant daily rhythm occurs is approximately 15 degrees C in S. punctatus compared with approximately 25 degrees C in T. rugosa. This difference probably reflects the disparate thermoregulatory adaptations of the two species, S. punctatus favoring mean activity temperatures of 11.5 degrees C and T. rugosa, 32.5 degrees C. In ectotherms such as reptiles, therefore, species-typical thermoregulatory behavior may provide thermal cues that interact with photoperiod to provide the appropriate melatonin signal for the regulation of annual physiological cycles.

scholarly journals Vibrotactile feedback improves balance and mobility in patients with severe bilateral vestibular loss

2018 ◽  
Vol 266 (S1) ◽  
pp. 19-26 ◽  
Author(s):  
Herman Kingma ◽  
Lilian Felipe ◽  
Marie-Cecile Gerards ◽  
Peter Gerits ◽  
Nils Guinand ◽  
...  
Keyword(s):  
Vibrotactile Feedback ◽  
Vestibular Loss ◽  
Bilateral Vestibular Loss

scholarly journals Effect of Testosterone on Lead Acetate Toxicity in Male Albino Rats

2017 ◽  
Vol 2 (2) ◽  
pp. 112-120
Author(s):  
Nazar Mohammed Shareef Mahmood ◽  
Sarkawt Hamad Ameen Hamad ◽  
Dlshad Hussein Hassan ◽  
Karwan Ismael Othman
Keyword(s):  
Lead Acetate ◽  
Toxic Substance ◽  
Male Rats ◽  
Control Group ◽  
Albino Rats ◽  
Central Vein ◽  
Cell Degeneration ◽  
Group I ◽  
Liver And Kidney ◽  
Adverse Influence

The toxicity of lead acetate (L. A.) concerned to public health disruptor due to its persistence in the environment and it has the adverse influence on the human and animal health as well. It causes physiological,biochemical, and neurological dysfunctions in humans. Histologically it has a negative effect on the liver which is considered one of the major target organs where acts as detoxification machine by elimination the toxic substance from the blood in rich with it.  As well as it affects kidneys that are the two of the most filtering organs. Therefore the present study was aimed to investigate the histopathological effect of L.A. on liver and kidney tissues in male rats. Twenty male rats involved in the study were equally and randomly divided into two groups each of them involved 10 animals. Group I (castrated rats) and Group II (control) each group received 80mg/L of lead acetate dissolved in one liter distilled water by drinking for 15 days. Histological sections showed some alterations including abnormal architecture, cell degeneration, nuclear degeneration, hyperchromatic hepatocytes, immune cells, degeneration in tubules, dilation in sinusoids, dilation in central vein of liver increased bowman's space glomerular atrophy degeneration of tubular cells in liver and kidney tissues of rats in castrated rats from control group. But the size of degenerated tissue was more severe in castrated male rats. It was concluded that the castration process could produce a hypogonadism and decreased testosterone which owns many receptors in kidney and liver may produce adverse influence with L.A. administration.

scholarly journals Chronic Electrical Stimulation of the Otolith Organ: Preliminary Results in Humans with Bilateral Vestibulopathy and Sensorineural Hearing Loss

2019 ◽  
Vol 25 (Suppl. 1-2) ◽  
pp. 79-90 ◽  
Author(s):  
Angel Ramos Macias ◽  
Angel Ramos de Miguel ◽  
Isaura Rodriguez Montesdeoca ◽  
Silvia Borkoski Barreiro ◽  
Juan Carlos Falcón González
Keyword(s):  
Electrical Stimulation ◽  
Vestibular Evoked Myogenic Potentials ◽  
Head Impulse Test ◽  
Clinical Test ◽  
Otolith Organ ◽  
Bilateral Vestibulopathy ◽  
Vestibular Loss ◽  
Bilateral Vestibular Loss ◽  
Chronic Electrical Stimulation ◽  
Stimulation Of

Introduction: Bilateral vestibulopathy is an important cause of imbalance that is misdiagnosed. The clinical management of patients with bilateral vestibular loss remains difficult as there is no clear evidence for an effective treatment. In this paper, we try to analyze the effect of chronic electrical stimulation and adaptation to electrical stimulation of the vestibular system in humans when stimulating the otolith organ with a constant pulse train to mitigate imbalance due to bilateral vestibular dysfunction (BVD). Methods: We included 2 patients in our study with BVD according to Criteria Consensus of the Classification Committee of the Bárány Society. Both cases were implanted by using a full-band straight electrode to stimulate the otoliths organs and simultaneously for the cochlear stimulation we use a perimodiolar electrode. Results: In both cases Vestibular and clinical test (video head impulse test, videonistagmography cervical vestibular evoked myogenic potentials, cVEMP and oVEMP), subjective visual vertical test, computerized dynamic posturography, dynamic gait index, Time UP and Go test and dizziness handicap index) were performed. Posture and gait metrics reveal important improvement if compare with preoperartive situation. Oscillopsia, unsteadiness, independence and quality of life improved to almost normal situation. Discussion/Conclusion: Prosthetic implantation of the otolith organ in humans is technically feasible. Electrical stimulation might have potential effects on balance and this is stable after 1 year follow-up. This research provides new possibilities for the development of vestibular implants to improve gravito-inertial acceleration sensation, in this case by the otoliths stimulation.

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