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Hu J, Han Y, Luo A, Zhang H, Tian L, Cai H, Xue B, Lai R, Luo L. Gating elements for carvacrol activation of the OTOP1 proton channel. Commun Biol 2024; 7:1106. [PMID: 39251752 PMCID: PMC11384762 DOI: 10.1038/s42003-024-06818-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2024] [Accepted: 08/30/2024] [Indexed: 09/11/2024] Open
Abstract
Otopetrin 1 (OTOP1) is a proton-activated channel crucial for animals' perception of sour taste. Despite its significance, the gating mechanism of OTOP1 remains poorly understood. Here, we demonstrate that carvacrol activates the mouse OTOP1 (mOTOP1) channel under neutral and acidic conditions. Functional analysis showed that carvacrol enhances pH fluorescence signals in OTOP1-expressing cells, with reduced efficacy at lower pH levels. Carvacrol selectively activates mOTOP1, while mOTOP2, mOTOP3, and Chelonia mydas OTOP1 (CmOTOP1) are insensitive to carvacrol activation under neutral pH. Through chimera and point mutation experiments, swapping S134 in transmembrane segment 3 (TM3) and T247 in the TM5-6 linker abolished carvacrol activation of mOTOP1 and conferred activation on CmOTOP1, suggesting these two residues are critical for carvacrol sensitivity. These findings highlight TM3 and TM5-6 linker as pivotal gating apparatus of OTOP1 channels and potential docking sites for drug design.
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Affiliation(s)
- Jingmei Hu
- Engineering Laboratory of Peptides of Chinese Academy of Sciences, Key Laboratory of Bioactive Peptides of Yunnan Province, KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, National Resource Center for Non-Human Primates, National Research Facility for Phenotypic & Genetic Analysis of Model Animals (Primate Facility), Key Laboratory of Genetic Evolution & Animal Models, Sino-African Joint Research Center, and New Cornerstone Science Laboratory, Kunming Institute of Zoology, the Chinese Academy of Sciences, Kunming, Yunnan, China
- Kunming College of Life Science, University of Chinese Academy of Sciences, Beijing, China
| | - Yalan Han
- Engineering Laboratory of Peptides of Chinese Academy of Sciences, Key Laboratory of Bioactive Peptides of Yunnan Province, KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, National Resource Center for Non-Human Primates, National Research Facility for Phenotypic & Genetic Analysis of Model Animals (Primate Facility), Key Laboratory of Genetic Evolution & Animal Models, Sino-African Joint Research Center, and New Cornerstone Science Laboratory, Kunming Institute of Zoology, the Chinese Academy of Sciences, Kunming, Yunnan, China
| | - Anna Luo
- Engineering Laboratory of Peptides of Chinese Academy of Sciences, Key Laboratory of Bioactive Peptides of Yunnan Province, KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, National Resource Center for Non-Human Primates, National Research Facility for Phenotypic & Genetic Analysis of Model Animals (Primate Facility), Key Laboratory of Genetic Evolution & Animal Models, Sino-African Joint Research Center, and New Cornerstone Science Laboratory, Kunming Institute of Zoology, the Chinese Academy of Sciences, Kunming, Yunnan, China
| | - Hao Zhang
- Engineering Laboratory of Peptides of Chinese Academy of Sciences, Key Laboratory of Bioactive Peptides of Yunnan Province, KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, National Resource Center for Non-Human Primates, National Research Facility for Phenotypic & Genetic Analysis of Model Animals (Primate Facility), Key Laboratory of Genetic Evolution & Animal Models, Sino-African Joint Research Center, and New Cornerstone Science Laboratory, Kunming Institute of Zoology, the Chinese Academy of Sciences, Kunming, Yunnan, China
| | - Lifeng Tian
- Engineering Laboratory of Peptides of Chinese Academy of Sciences, Key Laboratory of Bioactive Peptides of Yunnan Province, KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, National Resource Center for Non-Human Primates, National Research Facility for Phenotypic & Genetic Analysis of Model Animals (Primate Facility), Key Laboratory of Genetic Evolution & Animal Models, Sino-African Joint Research Center, and New Cornerstone Science Laboratory, Kunming Institute of Zoology, the Chinese Academy of Sciences, Kunming, Yunnan, China
| | - Huajun Cai
- Engineering Laboratory of Peptides of Chinese Academy of Sciences, Key Laboratory of Bioactive Peptides of Yunnan Province, KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, National Resource Center for Non-Human Primates, National Research Facility for Phenotypic & Genetic Analysis of Model Animals (Primate Facility), Key Laboratory of Genetic Evolution & Animal Models, Sino-African Joint Research Center, and New Cornerstone Science Laboratory, Kunming Institute of Zoology, the Chinese Academy of Sciences, Kunming, Yunnan, China
- Kunming College of Life Science, University of Chinese Academy of Sciences, Beijing, China
- Department of Molecular and Cell Biology, School of Life Sciences, University of Science and Technology of China, Hefei, China
| | - Beiru Xue
- Engineering Laboratory of Peptides of Chinese Academy of Sciences, Key Laboratory of Bioactive Peptides of Yunnan Province, KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, National Resource Center for Non-Human Primates, National Research Facility for Phenotypic & Genetic Analysis of Model Animals (Primate Facility), Key Laboratory of Genetic Evolution & Animal Models, Sino-African Joint Research Center, and New Cornerstone Science Laboratory, Kunming Institute of Zoology, the Chinese Academy of Sciences, Kunming, Yunnan, China
- Kunming College of Life Science, University of Chinese Academy of Sciences, Beijing, China
- Department of Biopharmaceutical Sciences, College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu, China
| | - Ren Lai
- Engineering Laboratory of Peptides of Chinese Academy of Sciences, Key Laboratory of Bioactive Peptides of Yunnan Province, KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, National Resource Center for Non-Human Primates, National Research Facility for Phenotypic & Genetic Analysis of Model Animals (Primate Facility), Key Laboratory of Genetic Evolution & Animal Models, Sino-African Joint Research Center, and New Cornerstone Science Laboratory, Kunming Institute of Zoology, the Chinese Academy of Sciences, Kunming, Yunnan, China.
- Kunming College of Life Science, University of Chinese Academy of Sciences, Beijing, China.
- Department of Molecular and Cell Biology, School of Life Sciences, University of Science and Technology of China, Hefei, China.
- Department of Biopharmaceutical Sciences, College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu, China.
| | - Lei Luo
- Engineering Laboratory of Peptides of Chinese Academy of Sciences, Key Laboratory of Bioactive Peptides of Yunnan Province, KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, National Resource Center for Non-Human Primates, National Research Facility for Phenotypic & Genetic Analysis of Model Animals (Primate Facility), Key Laboratory of Genetic Evolution & Animal Models, Sino-African Joint Research Center, and New Cornerstone Science Laboratory, Kunming Institute of Zoology, the Chinese Academy of Sciences, Kunming, Yunnan, China.
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2
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Büki B, Migliaccio AA. The vergence-mediated gain increase: Physiology and clinical relevance. J Vestib Res 2023; 33:173-186. [PMID: 37005906 DOI: 10.3233/ves-220133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/30/2023]
Abstract
BACKGROUND During near-viewing, the vestibulo-ocular reflex (VOR) response/gain increases to compensate for the relatively larger translation of the eyes with respect to the target. OBJECTIVE To review vergence-mediated gain increase (VMGI) testing methods stimuli and responses (latency and amplitude), peripheral/central pathways and clinical relevance. METHODS The authors discuss publications listed in PUBMED since 1980 in the light of their own studies. RESULTS The VMGI can be measured during rotational, linear and combined head accelerations. It has short-latency, non-compensatory amplitude, and relies on irregularly discharging peripheral afferents and their pathways. It is driven by a combination of perception, visual-context and internal modelling. CONCLUSIONS Currently, there are technical barriers that hinder VMGI measurement in the clinic. However, the VMGI may have diagnostic value, especially with regards to measuring otolith function. The VMGI also may have potential value in rehabilitation by providing insight about a patient's lesion and how to best tailor a rehabilitation program for them, that potentially includes VOR adaptation training during near-viewing.
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Affiliation(s)
- Bela Büki
- Department of Otolaryngology, Karl Landsteiner University Hospital Krems, Mitterweg, Austria
| | - Americo A Migliaccio
- Balance and Vision Laboratory, Neuroscience Research Australia, Randwick, NSW, Australia
- Graduate School of Biomedical Engineering, University of NSW, Sydney, NSW, Australia
- Otolaryngology-Head and Neck Surgery, Johns Hopkins University, Baltimore, MD, USA
- School of Biomedical Sciences and Pharmacy, University of Newcastle, Newcastle, NSW, Australia
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3
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Unidirectional Vertical Vestibuloocular Reflex Adaptation in Humans Using 1D and 2D Scenes. Otol Neurotol 2022; 43:e1039-e1044. [PMID: 36075099 DOI: 10.1097/mao.0000000000003684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
HYPOTHESIS The vertical vestibuloocular reflex (VOR) in response to pitch head impulses can be optimally trained to increase in one direction using a two-dimensional (2D) visual training target with minimal effect on the horizontal VOR. BACKGROUND We modified the incremental VOR adaptation (IVA) technique, shown to increase the horizontal VOR in patients with vestibular hypofunction, to drive vertical VOR adaptation in healthy control subjects. METHODS We measured the horizontal and vertical active (self-generated) and passive (imposed) head impulse VOR gains (eye velocity/head velocity) before and after 15 minutes of unidirectional downward IVA training. IVA training consisted of two sessions, one using a single-dot one-dimensional (1D) target, the other a grid-of-dots 2D target. RESULTS The downward head impulse VOR gain significantly increased because of training by 13.3%, whereas the upward VOR gain did not change. The addition of extraretinal (2D) feedback did not result in greater adaptation, i.e., 1D and 2D gain increases were 15.5% and 10.6%, respectively. The vertical VOR gain increase resulted in a 3.2% decrease in horizontal VOR gain. CONCLUSION This preliminary study is the first to show that physiologically relevant (high frequency) unidirectional increases in vertical VOR gain are possible with just 15 minutes of training. This study sets the basis for future clinical trials examining vertical IVA training in patients, which may provide the first practical rehabilitation treatment to functionally improve the vertical VOR.
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Khan SI, Hübner PP, Brichta AM, Migliaccio AA. Vestibulo-Ocular Reflex Short-Term Adaptation Is Halved After Compensation for Unilateral Labyrinthectomy. J Assoc Res Otolaryngol 2022; 23:457-466. [PMID: 35313363 DOI: 10.1007/s10162-022-00844-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2021] [Accepted: 03/02/2022] [Indexed: 11/24/2022] Open
Abstract
Several prior studies, including those from this laboratory, have suggested that vestibulo-ocular reflex (VOR) adaptation and compensation are two neurologically related mechanisms. We therefore hypothesised that adaptation would be affected by compensation, depending on the amount of overlap between these two mechanisms. To better understand this overlap, we examined the effect of gain-increase (gain = eye velocity/head velocity) adaptation training on the VOR in compensated mice since both adaptation and compensation mechanisms are presumably driving the gain to increase. We tested 11 cba129 controls and 6 α9-knockout mice, which have a compromised efferent vestibular system (EVS) known to affect both adaptation and compensation mechanisms. Baseline VOR gains across frequencies (0.2 to 10 Hz) and velocities (20 to 100°/s) were measured on day 28 after unilateral labyrinthectomy (UL) and post-adaptation gains were measured after gain-increase training on day 31 post-UL. Our findings showed that after chronic compensation gain-increase adaptation, as a percentage of baseline, in both strains of mice (~14%), was about half compared to their previously reported healthy, non-operated counterparts (~32%). Surprisingly, there was no difference in gain-increase adaptation between control and α9-knockout mice. These data support the notion that adaptation and compensation are separate but overlapping processes. They also suggest that half of the original adaptation capacity remained in chronically compensated mice, regardless of EVS compromise associated with α9-knockout mice, and strongly suggest VOR adaptation training is a viable treatment strategy for vestibular rehabilitation therapy and, importantly, augments the compensatory process.
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Affiliation(s)
- Serajul I Khan
- Balance and Vision Laboratory, Neuroscience Research Australia, Cnr Barker Street & Easy Street, Randwick, Sydney, NSW, 2031, Australia.,University of New South Wales, Sydney, NSW, 2033, Australia
| | - Patrick P Hübner
- Balance and Vision Laboratory, Neuroscience Research Australia, Cnr Barker Street & Easy Street, Randwick, Sydney, NSW, 2031, Australia.,University of New South Wales, Sydney, NSW, 2033, Australia
| | - Alan M Brichta
- School of Biomedical Sciences and Pharmacy, University of Newcastle, Newcastle, Australia
| | - Americo A Migliaccio
- Balance and Vision Laboratory, Neuroscience Research Australia, Cnr Barker Street & Easy Street, Randwick, Sydney, NSW, 2031, Australia. .,University of New South Wales, Sydney, NSW, 2033, Australia. .,School of Biomedical Sciences and Pharmacy, University of Newcastle, Newcastle, Australia. .,Department of Otolaryngology - Head and Neck Surgery, Johns Hopkins University, Baltimore, MD, 21205, USA.
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5
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A Once-Daily High Dose of Intraperitoneal Ascorbate Improves Vestibulo-ocular Reflex Compensation After Unilateral Labyrinthectomy in the Mouse. J Assoc Res Otolaryngol 2022; 23:27-34. [PMID: 34981264 PMCID: PMC8782995 DOI: 10.1007/s10162-021-00831-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Accepted: 12/15/2021] [Indexed: 02/03/2023] Open
Abstract
Ascorbate potentiates the response of nicotinic-acetylcholine-receptors containing α9 and α10 subunits found predominantly in the efferent systems of the inner ear, such as the efferent vestibular system (EVS). Prior mouse studies have shown that an attenuated EVS results in reduced vestibulo-ocular reflex (VOR) gain (=eye_velocity/head_velocity) plasticity in intact (VOR adaptation) and surgically-lesioned (VOR compensation) mice. We sought to determine whether ascorbate-treatment could improve VOR recovery after vestibular organ injury, possibly through potentiation of the EVS pathway. We tested 10 cba129 mice, 5 received ascorbate-treatment and 5 did not, but otherwise experienced the same conditions. Ascorbate-treatment comprised a once-daily intraperitoneal injection of L-form reduced ascorbate (4 g/kg) in 0.2 ml saline starting 1 week before, and ending 4 weeks after, unilateral labyrinthectomy surgery. These were deliberately high doses to determine the ascorbate effects on recovery. Baseline, acute, and chronic sinusoidal VOR gains (frequency and velocity ranges: 0.2-10 Hz, 20-100 deg/s) were measured 3-5 days before, 3-5 days after, and 28-31 days after labyrinthectomy. Mice treated with ascorbate had acute ipsilesional VOR gains 12 % higher compared to control mice (+45.2 ± 14.9 % from baseline versus +33.7 ± 15.4 %, P < 0.001). Similarly, chronic ipsilesional and contralesional VOR gains were respectively 16 % (+74.3 ± 16.3 % from baseline versus +58.1 ± 15.8 %, P < 0.001) and 13 % (+78.6 ± 16.0 % versus +65.6 ± 10.9 %, P < 0.001) higher compared to control mice. These data suggest ascorbate-treatment had a prophylactic effect reducing acute loss, and helped recovery during acute to chronic stages of compensation. One possible mechanism is that an ascorbate-enhanced EVS drives an increase in the number and sensitivity of irregular-discharging primary vestibular afferents, important for VOR plasticity.
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Fotsing JR, Darmohusodo V, Patron AP, Ching BW, Brady T, Arellano M, Chen Q, Davis TJ, Liu H, Servant G, Zhang L, Williams M, Saganich M, Ditschun T, Tachdjian C, Karanewsky DS. Discovery and Development of S6821 and S7958 as Potent TAS2R8 Antagonists. J Med Chem 2020; 63:4957-4977. [PMID: 32330040 DOI: 10.1021/acs.jmedchem.0c00388] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
In humans, bitter taste is mediated by 25 TAS2Rs. Many compounds, including certain active pharmaceutical ingredients, excipients, and nutraceuticals, impart their bitter taste (or in part) through TAS2R8 activation. However, effective TAS2R8 blockers that can either suppress or reduce the bitterness of these compounds have not been described. We are hereby reporting a series of novel 3-(pyrazol-4-yl) imidazolidine-2,4-diones as potent and selective TAS2R8 antagonists. In human sensory tests, S6821 and S7958, two of the most potent analogues from the series, demonstrated efficacy in blocking TAS2R8-mediated bitterness and were selected for development. Following data evaluation by expert panels of a number of national and multinational regulatory bodies, including the US, the EU, and Japan, S6821 and S7958 were approved as safe under conditions of intended use as bitter taste blockers.
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Affiliation(s)
- Joseph R Fotsing
- Firmenich SA, R&D North America, San Diego site, 4767 Nexus Centre Drive, San Diego, California 92121, United States
| | - Vincent Darmohusodo
- Firmenich SA, R&D North America, San Diego site, 4767 Nexus Centre Drive, San Diego, California 92121, United States
| | - Andrew P Patron
- Firmenich SA, R&D North America, San Diego site, 4767 Nexus Centre Drive, San Diego, California 92121, United States
| | - Brett W Ching
- Firmenich SA, R&D North America, San Diego site, 4767 Nexus Centre Drive, San Diego, California 92121, United States
| | - Thomas Brady
- Firmenich SA, R&D North America, San Diego site, 4767 Nexus Centre Drive, San Diego, California 92121, United States
| | - Melissa Arellano
- Firmenich SA, R&D North America, San Diego site, 4767 Nexus Centre Drive, San Diego, California 92121, United States
| | - Qing Chen
- Firmenich SA, R&D North America, San Diego site, 4767 Nexus Centre Drive, San Diego, California 92121, United States
| | - Timothy J Davis
- Firmenich SA, R&D North America, San Diego site, 4767 Nexus Centre Drive, San Diego, California 92121, United States
| | - Hanghui Liu
- Firmenich SA, R&D North America, San Diego site, 4767 Nexus Centre Drive, San Diego, California 92121, United States
| | - Guy Servant
- Firmenich SA, R&D North America, San Diego site, 4767 Nexus Centre Drive, San Diego, California 92121, United States
| | - Lan Zhang
- Firmenich SA, R&D North America, San Diego site, 4767 Nexus Centre Drive, San Diego, California 92121, United States
| | - Mark Williams
- Firmenich SA, R&D North America, San Diego site, 4767 Nexus Centre Drive, San Diego, California 92121, United States
| | - Michael Saganich
- Firmenich SA, R&D North America, San Diego site, 4767 Nexus Centre Drive, San Diego, California 92121, United States
| | - Tanya Ditschun
- Firmenich SA, R&D North America, San Diego site, 4767 Nexus Centre Drive, San Diego, California 92121, United States
| | - Catherine Tachdjian
- Firmenich SA, R&D North America, San Diego site, 4767 Nexus Centre Drive, San Diego, California 92121, United States
| | - Donald S Karanewsky
- Firmenich SA, R&D North America, San Diego site, 4767 Nexus Centre Drive, San Diego, California 92121, United States
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7
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Millar JL, Gimmon Y, Roberts D, Schubert MC. Improvement After Vestibular Rehabilitation Not Explained by Improved Passive VOR Gain. Front Neurol 2020; 11:79. [PMID: 32153490 PMCID: PMC7044341 DOI: 10.3389/fneur.2020.00079] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 01/22/2020] [Indexed: 01/13/2023] Open
Abstract
Gaze stability exercises are a critical component of vestibular rehabilitation for individuals with vestibular hypofunction and many studies reveal the rehabilitation improves functional performance. However, few studies have examined the vestibular physiologic mechanisms (semicircular canal; otolith) responsible for such recovery after patients with vestibular hypofunction complete gaze and gait stability exercises. The purpose of this study was to compare behavioral outcome measures (i.e., visual acuity during head rotation) with physiological measures (i.e., gain of the vestibulo-ocular reflex) of gaze stability following a progressive vestibular rehabilitation program in patients following unilateral vestibular deafferentation surgery (UVD). We recruited n = 43 patients (n = 18 female, mean 52 ± 13 years, range 23-80 years) after unilateral deafferentation from vestibular schwannoma; n = 38 (25 female, mean 46.9 ± 15.9 years, range 22-77 years) age-matched healthy controls for dynamic visual acuity testing, and another n = 28 (14 female, age 45 ± 17, range 20-77 years) healthy controls for video head impulse testing. Data presented is from n = 19 patients (14 female, mean 48.9 ± 14.7 years) with UVD who completed a baseline assessment ~6 weeks after surgery, 5 weeks of vestibular physical therapy and a final measurement. As a group, subjective and fall risk measures improved with a meaningful clinical relevance. Dynamic visual acuity (DVA) during active head rotation improved [mean ipsilesional 38.57% ± 26.32 (n = 15/19)]; mean contralesional 39.96% ± 22.62 (n = 12/19), though not uniformly. However, as a group passive yaw VOR gain (mean ipsilesional pre 0.44 ± 0.18 vs. post 0.44 ± 0.15; mean contralesional pre 0.81 ± 0.19 vs. post 0.85 ± 0.09) did not show any change (p ≥ 0.4) after rehabilitation. The velocity of the overt compensatory saccades during ipsilesional head impulses were reduced after rehabilitation; no other metric of oculomotor function changed (p ≥ 0.4). Preserved utricular function was correlated with improved yaw DVA and preserved saccular function was correlated with improved pitch DVA. Our results suggest that 5 weeks of vestibular rehabilitation using gaze and gait stability exercises improves both subjective and behavioral performance despite absent change in VOR gain in a majority of patients, and that residual otolith function appears correlated with such change.
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Affiliation(s)
- Jennifer L Millar
- Department of Physical Medicine and Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, MD, United States.,Laboratory of Vestibular NeuroAdaptation, Department of Otolaryngology - Head and Neck Surgery, Baltimore, MD, United States
| | - Yoav Gimmon
- Laboratory of Vestibular NeuroAdaptation, Department of Otolaryngology - Head and Neck Surgery, Baltimore, MD, United States.,Department of Physical Therapy, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Dale Roberts
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Michael C Schubert
- Department of Physical Medicine and Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, MD, United States.,Laboratory of Vestibular NeuroAdaptation, Department of Otolaryngology - Head and Neck Surgery, Baltimore, MD, United States
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8
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Smith PF. The Growing Evidence for the Importance of the Otoliths in Spatial Memory. Front Neural Circuits 2019; 13:66. [PMID: 31680880 PMCID: PMC6813194 DOI: 10.3389/fncir.2019.00066] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Accepted: 09/30/2019] [Indexed: 01/14/2023] Open
Abstract
Many studies have demonstrated that vestibular sensory input is important for spatial learning and memory. However, it has been unclear what contributions the different parts of the vestibular system - the semi-circular canals and otoliths - make to these processes. The advent of mutant otolith-deficient mice has made it possible to isolate the relative contributions of the otoliths, the utricle and saccule. A number of studies have now indicated that the loss of otolithic function impairs normal spatial memory and also impairs the normal function of head direction cells in the thalamus and place cells in the hippocampus. Epidemiological studies have also provided evidence that spatial memory impairment with aging, may be linked to saccular function. The otoliths may be important in spatial cognition because of their evolutionary age as a sensory detector of orientation and the fact that velocity storage is important to the way that the brain encodes its place in space.
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Affiliation(s)
- Paul F. Smith
- Department of Pharmacology and Toxicology, Brain Health Research Centre, School of Biomedical Sciences, University of Otago Medical School, Dunedin, New Zealand
- Brain Research New Zealand, Auckland, New Zealand
- Eisdell Moore Centre for Hearing and Balance Research, University of Auckland, Auckland, New Zealand
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9
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Schubert MC, Migliaccio AA. New advances regarding adaptation of the vestibulo-ocular reflex. J Neurophysiol 2019; 122:644-658. [PMID: 31215309 DOI: 10.1152/jn.00729.2018] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
This is a review summarizing the development of vestibulo-ocular reflex (VOR) adaptation behavior with relevance to rehabilitation over the last 10 years and examines VOR adaptation using head-on-body rotations, specifically the influence of training target contrast, position and velocity error signal, active vs. passive head rotations, and sinusoidal vs. head impulse rotations. This review discusses optimization of the single VOR adaptation training session, consolidation between repeated training sessions, and dynamic incremental VOR adaptation. Also considered are the effects of aging and the roles of the efferent vestibular system, cerebellum, and otoliths on angular VOR adaptation. Finally, this review examines VOR adaptation findings in studies using whole body rotations.
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Affiliation(s)
- Michael C Schubert
- Laboratory of Vestibular NeuroAdaptation, Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins University, Baltimore, Maryland.,Department of Physical Medicine and Rehabilitation, Johns Hopkins University, Baltimore, Maryland
| | - Americo A Migliaccio
- Balance and Vision Laboratory, Neuroscience Research Australia, Sydney, New South Wales, Australia.,Graduate School of Biomedical Engineering, University of New South Wales, Sydney, New South Wales, Australia.,Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins University, Baltimore, Maryland.,School of Biomedical Sciences, University of Newcastle, Newcastle, New South Wales, Australia
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