- cVEMP correlated with imbalance in a mouse model of vestibular disorder. [Journal Article]
- EHEnviron Health Prev Med 2019 Jun 01; 24(1):39
- CONCLUSIONS: This study demonstrated impaired cVEMP and correlations of cVEMP with imbalance determined by behavior tests in a mouse model of vestibular disorder.
- Growth and cellular patterning during fetal human inner ear development studied by a correlative imaging approach. [Journal Article]
- BDBMC Dev Biol 2019 May 20; 19(1):11
- CONCLUSIONS: We present structural information on human inner ear development across multiple levels of biological organization, including gross-morphology of the inner ear, cellular and subcellular details of hearing and vestibular organs, as well as ultrastructural details in the developing sensory epithelia. This enabled the gathering of detailed information regarding morphometric changes as well in realizing the complex developmental patterns of the human inner ear. We were able to quantify the volumetric and linear aspects of selected gestational inner ear specimens enabling a better understanding of the cellular changes across the fetal gestational timeline. Moreover, these data could serve as a reference for better understanding disorders that arise during inner ear development.
- Otopetrin-2 Immunolocalization in the Human Macula Utricle. [Journal Article]
- AOAnn Otol Rhinol Laryngol 2019; 128(6_suppl):96S-102S
- CONCLUSIONS: Otopetrin-2 was localized in supporting cells in a similar fashion that otopetrin-1 previously reported in the mouse macula utricle. The differential expression of otopetrin-2 in the supporting cells of the human macula utricle suggest an important role in the vestibular sensory periphery homeostasis and otolith maintenance.
- On the Legacy of Genetically Altered Mouse Models to Explore Vestibular Function: Distribution of Vestibular Hair Cell Phenotypes in the Otoferlin-Null Mouse. [Journal Article]
- AOAnn Otol Rhinol Laryngol 2019; 128(6_suppl):125S-133S
- CONCLUSIONS: These findings support the notion that modifications resulting in a specific component of vestibular hypofunction are not accompanied by widespread morphologic and cellular changes in the vestibular sensory epithelia.
- Sacculus-Utriculus Confluence Criterion (SUCC). [Journal Article]
- ONOtol Neurotol 2019; 40(5):e566-e568
- Deletion of Brg1 causes stereocilia bundle fusion and cuticular plate loss in vestibular hair cells. [Journal Article]
- HRHear Res 2019; 377:247-259
- Brg1 is an ATPase subunit of the SWI/SNF chromatin-remodeling complex, and it is indispensable for the development and homeostasis of various organs. Conditional deletion of Brg1 in cochlea hair cell…
Brg1 is an ATPase subunit of the SWI/SNF chromatin-remodeling complex, and it is indispensable for the development and homeostasis of various organs. Conditional deletion of Brg1 in cochlea hair cells (HCs) leads to multiple structural defects and profound deafness. However, the premature death of Brg1-deficient cochlea HCs hindered further study of the role of Brg1. In contrast to cochlea HCs, Brg1-deficient vestibular HCs survived for a long time. Therefore, HC apical structure and vestibular function were examined in inner HC-specific conditional Brg1 knockout mice. Vestibular HCs exhibited fused and elongated stereocilia bundles after deletion of Brg1, and the cuticular plate was absent in most HCs with fused stereocilia bundles. HC loss was observed in conditional Brg1 knockout mice at the age of 12 months. Morphological defects and HC loss were primarily restricted in the striolar region of the utricle and saccule and in the central region of ampulla. The behavioral tests revealed that Brg1 deletion in HCs caused vestibular dysfunction in older adult mice. These results suggest that Brg1 may play specific roles in the maintenance of the HC stereocilia bundle and the cuticular plate.
- Angular vestibuloocular reflex responses in Otop1 mice. I. Otolith sensor input is essential for gravity context-specific adaptation. [Journal Article]
- JNJ Neurophysiol 2019 Jun 01; 121(6):2291-2299
- The role of the otoliths in mammals in the angular vestibuloocular reflex (VOR) has been difficult to determine because there is no surgical technique that can reliably ablate them without damaging t…
The role of the otoliths in mammals in the angular vestibuloocular reflex (VOR) has been difficult to determine because there is no surgical technique that can reliably ablate them without damaging the semicircular canals. The Otopetrin1 (Otop1) mouse lacks functioning otoliths because of failure to develop otoconia but seems to have otherwise normal peripheral anatomy and neural circuitry. By using these animals we sought to determine the role of the otoliths in angular VOR baseline function and adaptation. In six Otop1 mice and six control littermates we measured baseline ocular countertilt about the three primary axes in head coordinates; baseline horizontal (rotation about an Earth-vertical axis parallel to the dorsal-ventral axis) and vertical (rotation about an Earth-vertical axis parallel to the interaural axis) sinusoidal (0.2-10 Hz, 20-100°/s) VOR gain (= eye/head velocity); and the horizontal and vertical VOR after gain-increase (1.5×) and gain-decrease (0.5×) adaptation training. Countertilt responses were significantly reduced in Otop1 mice. Baseline horizontal and vertical VOR gains were similar between mouse types, and so was horizontal VOR adaptation. For control mice, vertical VOR adaptation was evident when the testing context, left ear down (LED) or right ear down (RED), was the same as the training context (LED or RED). For Otop1 mice, VOR adaptation was evident regardless of context. Our results suggest that the otolith translational signal does not contribute to the baseline angular VOR, probably because the mouse VOR is highly compensatory, and does not alter the magnitude of adaptation. However, we show that the otoliths are important for gravity context-specific angular VOR adaptation. NEW & NOTEWORTHY This is the first study examining the role of the otoliths (defined here as the utricle and saccule) in adaptation of the angular vestibuloocular reflex (VOR) in an animal model in which the otoliths are reliably inactivated and the semicircular canals preserved. We show that they do not contribute to adaptation of the normal angular VOR. However, the otoliths provide the main cue for gravity context-specific VOR adaptation.
- Angular vestibuloocular reflex responses in Otop1 mice. II. Otolith sensor input improves compensation after unilateral labyrinthectomy. [Journal Article]
- JNJ Neurophysiol 2019 Jun 01; 121(6):2300-2307
- The role of the otoliths in mammals in the normal angular vestibuloocular reflex (VOR) was characterized in an accompanying study based on the Otopetrin1 (Otop1) mouse, which lacks functioning otolit…
The role of the otoliths in mammals in the normal angular vestibuloocular reflex (VOR) was characterized in an accompanying study based on the Otopetrin1 (Otop1) mouse, which lacks functioning otoliths because of failure to develop otoconia but seems to have otherwise normal peripheral anatomy and neural circuitry. That study showed that otoliths do not contribute to the normal horizontal (rotation about Earth-vertical axis parallel to dorso-ventral axis) and vertical (rotation about Earth-vertical axis parallel to interaural axis) angular VOR but do affect gravity context-specific VOR adaptation. By using these animals, we sought to determine whether the otoliths play a role in the angular VOR after unilateral labyrinthectomy when the total canal signal is reduced. In five Otop1 mice and five control littermates we measured horizontal and vertical left-ear-down and right-ear-down sinusoidal VOR (0.2-10 Hz, 20-100°/s) during the early (3-5 days) and plateau (28-32 days) phases of compensation after unilateral labyrinthectomy and compared these measurements with baseline preoperative responses from the accompanying study. From similar baselines, acute gain loss was ~25% less in control mice, and chronic gain recovery was ~40% more in control mice. The acute data suggest that the otoliths contribute to the angular VOR when there is a loss of canal function. The chronic data suggest that a unilateral otolith signal can significantly improve angular VOR compensation. These data have implications for vestibular rehabilitation of patients with both canal and otolith loss and the development of vestibular implants, which currently only mimic the canals on one side. NEW & NOTEWORTHY This is the first study examining the role of the otoliths (defined here as the utricle and saccule) on the acute and chronic angular vestibuloocular reflex (VOR) after unilateral labyrinthectomy in an animal model in which the otoliths are reliably inactivated and the semicircular canals preserved. This study shows that the otolith signal is used to augment the acute angular VOR and help boost VOR compensation after peripheral injury.
- Sacculatane diterpenoids from the Chinese liverwort Pellia epiphylla with protection against H2O2-induced apoptosis of PC12 cells. [Journal Article]
- PPhytochemistry 2019; 162:173-182
- Eight previously undescribed sacculatane diterpenoids, epiphyllins A-H, and one unknown bibenzyl-based isopentene along with seven known compounds were isolated from the Chinese liverwort Pellia epip…
Eight previously undescribed sacculatane diterpenoids, epiphyllins A-H, and one unknown bibenzyl-based isopentene along with seven known compounds were isolated from the Chinese liverwort Pellia epiphylla (L.) Corda. Their structures were established unequivocally on the basis of spectroscopic data and CD measurement. The quinine reductase-inducing activity evaluation demonstrated that epiphyllins A-D, 1β-hydroxysacculatanolide and pellianolactone B displayed moderate antioxidant effect. Further investigation of pellianolactone B revealed its protective effects on H2O2-induced oxidative insults and apoptosis in PC12 cells.
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- Vestibular function in panic disorder patients: a vestibular-evoked myogenic potentials and video head impulse test study. [Journal Article]
- EAEur Arch Otorhinolaryngol 2019; 276(6):1607-1616
- CONCLUSIONS: The VEMPs and vHIT tests demonstrated that there is no evidence of hypofunction of the semicircular canals in the high-frequency spectrum of VOR functioning. Nor are there any indications of impairment of the otolith system in patients with PD, regardless of their subjective vestibular sensations. The findings of the current study confirm the proposed link between anxiety, panic symptoms and postural instability in PD patients.