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Manrique-Huarte R, Garaycochea O, Troconis DP, Pérez-Fernández N, Manrique M. Histopathological reaction in the vestibule after cochlear implantation in Macaca fascicularis. J Neurol Sci 2023; 450:120672. [PMID: 37210936 DOI: 10.1016/j.jns.2023.120672] [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: 01/04/2022] [Revised: 05/02/2023] [Accepted: 05/05/2023] [Indexed: 05/23/2023]
Abstract
Cochlear implantation surgery (CI) is considered a safe procedure and is the standard treatment for the auditory rehabilitation in patients with severe-to-profound sensorineural hearing loss. Although the development of minimally traumatic surgical concepts (MTSC) have enabled the preservation of residual hearing after the implantation, there is scarce literature regarding the vestibular affection following MTCS. The aim of the study is to analyze histopathologic changes in the vestibule after CI in an animal model (Macaca fascicularis). Cochlear implantation was performed successfully in 14 ears following MTCS. They were classified in two groups upon type of electrode array used. Group A (n = 6) with a FLEX 28 electrode array and Group B (n = 8) with HL14 array. A 6-month follow-up was carried out with periodic objective auditory testing. After their sacrifice, histological processing and subsequent analysis was carried out. Intracochlear findings, vestibular presence of fibrosis, obliteration or collapse is analyzed. Saccule and utricle dimensions and neuroepithelium width is measured. Cochlear implantation was performed successfully in all 14 ears through a round window approach. Mean angle of insertion was >270° for group A and 180-270° for group B. In group A auditory deterioration was observed in Mf 1A, Mf2A and Mf5A with histopathological signs of scala tympani ossification, saccule collapse (Mf1A and Mf2A) and cochlear aqueduct obliteration (Mf5A). Besides, signs of endolymphatic sinus dilatation was seen for Mf2B and Mf5A. Regarding group B, no auditory deterioration was observed. Histopathological signs of endolymphatic sinus dilatation were seen in Mf 2B and Mf 8B. In conclusion, the risk of histological damage of the vestibular organs following minimally traumatic surgical concepts and the soft surgery principles is very low. CI surgery is a safe procedure and it can be done preserving the vestibular structures.
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Affiliation(s)
- Raquel Manrique-Huarte
- Department of Otorhinolaryngology, Clinica Universidad de Navarra, University of Navarra, Pamplona, Spain.
| | - Octavio Garaycochea
- Department of Otorhinolaryngology, Clinica Universidad de Navarra, University of Navarra, Pamplona, Spain.
| | - Daniella Parillis Troconis
- Department of Otorhinolaryngology, Clinica Universidad de Navarra, University of Navarra, Pamplona, Spain.
| | - Nicolás Pérez-Fernández
- Department of Otorhinolaryngology, Clinica Universidad de Navarra, University of Navarra, Pamplona, Spain.
| | - Manuel Manrique
- Department of Otorhinolaryngology, Clinica Universidad de Navarra, University of Navarra, Pamplona, Spain.
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Sung CYW, Barzik M, Costain T, Wang L, Cunningham LL. Semi-automated Quantification of Hair Cells in the Mature Mouse Utricle. Hear Res 2022; 416:108429. [PMID: 35081508 PMCID: PMC9034969 DOI: 10.1016/j.heares.2021.108429] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 11/19/2021] [Accepted: 12/28/2021] [Indexed: 02/09/2023]
Abstract
The mouse utricle model system is the best-characterized ex vivo preparation for studies of mature mammalian hair cells (HCs). Despite the many advantages of this model system, efficient and reliable quantification of HCs from cultured utricles has been a persistent challenge with this model system. Utricular HCs are commonly quantified by counting immunolabeled HCs in regions of interest (ROIs) placed over an image of the utricle. Our data indicate that the accuracy of HC counts obtained using this method can be impacted by variability in HC density across different regions of the utricle. In addition, the commonly used HC marker myosin 7a results in a diffuse cytoplasmic stain that is not conducive to automated quantification and must be quantified manually, a labor-intensive task. Furthermore, myosin 7a immunoreactivity is retained in dead HCs, resulting in inaccurate quantification of live HCs using this marker. Here we have developed a method for semi-automated quantification of surviving HCs that combines immunoreactivity for the HC-specific transcription factor Pou4f3 with labeling of activated caspase 3/7 (AC3/7) to detect apoptotic HCs. The discrete nuclear Pou4f3 signal allowed us to utilize the binary or threshold function within ImageJ to automate HC quantification. To further streamline this process, we created an ImageJ macro that automates the process from raw image loading to a final quantified image that can be immediately evaluated for accuracy. Within this quantified image, the user can manually correct the quantification via an image overlay indicating the counted HC nuclei. Pou4f3-positive HCs that also express AC3/7 are subtracted to yield accurate counts of surviving HCs. Overall, we present a semi-automated method that is faster than manual HC quantification and identifies surviving HCs with high accuracy.
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An Implanted Vestibular Prosthesis Improves Spatial Orientation in Animals with Severe Vestibular Damage. J Neurosci 2021; 41:3879-3888. [PMID: 33731447 DOI: 10.1523/jneurosci.2204-20.2021] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2020] [Revised: 02/10/2021] [Accepted: 03/08/2021] [Indexed: 11/21/2022] Open
Abstract
Gravity is a pervasive environmental stimulus, and accurate graviception is required for optimal spatial orientation and postural stability. The primary graviceptors are the vestibular organs, which include angular velocity (semicircular canals) and linear acceleration (otolith organs) sensors. Graviception is degraded in patients with vestibular damage, resulting in spatial misperception and imbalance. Since minimal therapy is available for these patients, substantial effort has focused on developing a vestibular prosthesis or vestibular implant (VI) that reproduces information normally provided by the canals (since reproducing otolith function is very challenging technically). Prior studies demonstrated that angular eye velocity responses could be driven by canal VI-mediated angular head velocity information, but it remains unknown whether a canal VI could improve spatial perception and posture since these behaviors require accurate estimates of angular head position in space relative to gravity. Here, we tested the hypothesis that a canal VI that transduces angular head velocity and provides this information to the brain via motion-modulated electrical stimulation of canal afferent nerves could improve the perception of angular head position relative to gravity in monkeys with severe vestibular damage. Using a subjective visual vertical task, we found that normal female monkeys accurately sensed the orientation of the head relative to gravity during dynamic tilts, that this ability was degraded following bilateral vestibular damage, and improved when the canal VI was used. These results demonstrate that a canal VI can improve graviception in vestibulopathic animals, suggesting that it could reduce the disabling perceptual and postural deficits experienced by patients with severe vestibular damage.SIGNIFICANCE STATEMENT Patients with vestibular damage experience impaired vision, spatial perception, and balance, symptoms that could potentially respond to a vestibular implant (VI). Anatomic features facilitate semicircular canal (angular velocity) prosthetics but inhibit approaches with the otolith (linear acceleration) organs, and canal VIs that sense angular head velocity can generate compensatory eye velocity responses in vestibulopathic subjects. Can the brain use canal VI head velocity information to improve estimates of head orientation (e.g., head position relative to gravity), which is a prerequisite for accurate spatial perception and posture? Here we show that a canal VI can improve the perception of head orientation in vestibulopathic monkeys, results that are highly significant because they suggest that VIs mimicking canal function can improve spatial orientation and balance in vestibulopathic patients.
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van de Berg R, Ramos A, van Rompaey V, Bisdorff A, Perez-Fornos A, Rubinstein JT, Phillips JO, Strupp M, Della Santina CC, Guinand N. The vestibular implant: Opinion statement on implantation criteria for research. J Vestib Res 2020; 30:213-223. [PMID: 32651339 PMCID: PMC9249290 DOI: 10.3233/ves-200701] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 05/20/2020] [Indexed: 12/26/2022]
Abstract
This opinion statement proposes a set of candidacy criteria for vestibular implantation of adult patients with bilateral vestibulopathy (BVP) in a research setting. The criteria include disabling chronic symptoms like postural imbalance, unsteadiness of gait and/or head movement-induced oscillopsia, combined with objective signs of reduced or absent vestibular function in both ears. These signs include abnormal test results recorded during head impulses (video head impulse test or scleral coil technique), bithermal caloric testing and rotatory chair testing (sinusoidal stimulation of 0.1 Hz). Vestibular implant (VI) implantation criteria are not the same as diagnostic criteria for bilateral vestibulopathy. The major difference between VI-implantation criteria and the approved diagnostic criteria for BVP are that all included vestibular tests of semicircular canal function (head impulse test, caloric test, and rotatory chair test) need to show significant impairments of vestibular function in the implantation criteria. For this, a two-step paradigm was developed. First, at least one of the vestibular tests needs to fulfill stringent criteria, close to those for BVP. If this is applicable, then the other vestibular tests have to fulfill a second set of criteria which are less stringent than the original criteria for BVP. If the VI-implantation is intended to excite the utricle and/or saccule (otolith stimulation), responses to cervical and ocular vestibular evoked myogenic potentials must be absent in addition to the above mentioned abnormalities of semicircular canal function. Finally, requirements for safe and potentially effective stimulation should be met, including implanting patients with BVP of peripheral origin only, and assessing possible medical and psychiatric contraindications.
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Affiliation(s)
- Raymond van de Berg
- Department of Otorhinolaryngology and Head & Neck Surgery, Maastricht University Medical Center+, Maastricht, The Netherlands
- Faculty of Physics, Tomsk State University, Tomsk, Russian Federation
| | - Angel Ramos
- Department of Otolaryngology Head Neck Surgery. Complejo Hospitalario Universitario Insular Materno Infantil de Gran Canaria. Department of Otolaryngology. Las Palmas University. (ULPGC). Psychoacoustic & Equilibrium Laboratory. Las Palmas University (ULPGC)
| | - Vincent van Rompaey
- Department of Otorhinolaryngology and Head & Neck Surgery, Antwerp University Hospital, Department of Translational Neurosciences, Faculty of Medicine and Health Sciences, University of Antwerp, Belgium
| | - Alexandre Bisdorff
- Clinique du Vertige, Centre Hospitalier Emile Mayrisch, Esch-sur-Alzette, Luxembourg
| | - Angelica Perez-Fornos
- Division of Otorhinolaryngology Head and Neck Surgery, Geneva University Hospitals and University of Geneva, Geneva, Switzerland
| | - Jay T. Rubinstein
- Otolaryngology-HNS, Virginia Merrill Bloedel Hearing Research Center, University of Washington, Seattle, WA, USA
| | - James O. Phillips
- Otolaryngology-HNS, Virginia Merrill Bloedel Hearing Research Center, University of Washington, Seattle, WA, USA
| | - Michael Strupp
- Department of Neurology and German Center for Vertigo and Balance Disorders, Ludwig Maximilians University, Munich, Germany
| | - Charles C. Della Santina
- Departments of Otolaryngology – Head & Neck Surgery and Biomedical Engineering, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Nils Guinand
- Division of Otorhinolaryngology Head and Neck Surgery, Geneva University Hospitals and University of Geneva, Geneva, Switzerland
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Hageman KN, Chow MR, Roberts D, Boutros PJ, Tooker A, Lee K, Felix S, Pannu SS, Haque R, Della Santina CC. Binocular 3D otolith-ocular reflexes: responses of chinchillas to prosthetic electrical stimulation targeting the utricle and saccule. J Neurophysiol 2019; 123:259-276. [PMID: 31747349 DOI: 10.1152/jn.00883.2018] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
From animal experiments by Cohen and Suzuki et al. in the 1960s to the first-in-human clinical trials now in progress, prosthetic electrical stimulation targeting semicircular canal branches of the vestibular nerve has proven effective at driving directionally appropriate vestibulo-ocular reflex eye movements, postural responses, and perception. That work was considerably facilitated by the fact that all hair cells and primary afferent neurons in each canal have the same directional sensitivity to head rotation, the three canals' ampullary nerves are geometrically distinct from one another, and electrically evoked three-dimensional (3D) canal-ocular reflex responses approximate a simple vector sum of linearly independent components representing relative excitation of each of the three canals. In contrast, selective prosthetic stimulation of the utricle and saccule has been difficult to achieve, because hair cells and afferents with many different directional sensitivities are densely packed in those endorgans and the relationship between 3D otolith-ocular reflex responses and the natural and/or prosthetic stimuli that elicit them is more complex. As a result, controversy exists regarding whether selective, controllable stimulation of electrically evoked otolith-ocular reflexes (eeOOR) is possible. Using micromachined, planar arrays of electrodes implanted in the labyrinth, we quantified 3D, binocular eeOOR responses to prosthetic electrical stimulation targeting the utricle, saccule, and semicircular canals of alert chinchillas. Stimuli delivered via near-bipolar electrode pairs near the maculae elicited sustained ocular countertilt responses that grew reliably with pulse rate and pulse amplitude, varied in direction according to which stimulating electrode was employed, and exhibited temporal dynamics consistent with responses expected for isolated macular stimulation.NEW & NOTEWORTHY As the second in a pair of papers on Binocular 3D Otolith-Ocular Reflexes, this paper describes new planar electrode arrays and vestibular prosthesis architecture designed to target the three semicircular canals and the utricle and saccule. With this technological advancement, electrically evoked otolith-ocular reflexes due to stimulation via utricle- and saccule-targeted electrodes were recorded in chinchillas. Results demonstrate advances toward achieving selective stimulation of the utricle and saccule.
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Affiliation(s)
- Kristin N Hageman
- Department of Biomedical Engineering, Johns Hopkins School of Medicine, Baltimore, Maryland
| | - Margaret R Chow
- Department of Biomedical Engineering, Johns Hopkins School of Medicine, Baltimore, Maryland
| | - Dale Roberts
- Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins School of Medicine, Baltimore, Maryland
| | - Peter J Boutros
- Department of Biomedical Engineering, Johns Hopkins School of Medicine, Baltimore, Maryland
| | - Angela Tooker
- Lawrence Livermore National Laboratory, Livermore, California
| | - Kye Lee
- Lawrence Livermore National Laboratory, Livermore, California
| | - Sarah Felix
- Lawrence Livermore National Laboratory, Livermore, California
| | | | - Razi Haque
- Lawrence Livermore National Laboratory, Livermore, California
| | - Charles C Della Santina
- Department of Biomedical Engineering, Johns Hopkins School of Medicine, Baltimore, Maryland.,Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins School of Medicine, Baltimore, Maryland
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Boutros PJ, Schoo DP, Rahman M, Valentin NS, Chow MR, Ayiotis AI, Morris BJ, Hofner A, Rascon AM, Marx A, Deas R, Fridman GY, Davidovics NS, Ward BK, Treviño C, Bowditch SP, Roberts DC, Lane KE, Gimmon Y, Schubert MC, Carey JP, Jaeger A, Della Santina CC. Continuous vestibular implant stimulation partially restores eye-stabilizing reflexes. JCI Insight 2019; 4:128397. [PMID: 31723056 DOI: 10.1172/jci.insight.128397] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Accepted: 10/04/2019] [Indexed: 12/17/2022] Open
Abstract
BACKGROUNDBilateral loss of vestibular (inner ear inertial) sensation causes chronically blurred vision during head movement, postural instability, and increased fall risk. Individuals who fail to compensate despite rehabilitation therapy have no adequate treatment options. Analogous to hearing restoration via cochlear implants, prosthetic electrical stimulation of vestibular nerve branches to encode head motion has garnered interest as a potential treatment, but prior studies in humans have not included continuous long-term stimulation or 3D binocular vestibulo-ocular reflex (VOR) oculography, without which one cannot determine whether an implant selectively stimulates the implanted ear's 3 semicircular canals.METHODSWe report binocular 3D VOR responses of 4 human subjects with ototoxic bilateral vestibular loss unilaterally implanted with a Labyrinth Devices Multichannel Vestibular Implant System vestibular implant, which provides continuous, long-term, motion-modulated prosthetic stimulation via electrodes in 3 semicircular canals.RESULTSInitiation of prosthetic stimulation evoked nystagmus that decayed within 30 minutes. Stimulation targeting 1 canal produced 3D VOR responses approximately aligned with that canal's anatomic axis. Targeting multiple canals yielded responses aligned with a vector sum of individual responses. Over 350-812 days of continuous 24 h/d use, modulated electrical stimulation produced stable VOR responses that grew with stimulus intensity and aligned approximately with any specified 3D head rotation axis.CONCLUSIONThese results demonstrate that a vestibular implant can selectively, continuously, and chronically provide artificial sensory input to all 3 implanted semicircular canals in individuals disabled by bilateral vestibular loss, driving reflexive VOR eye movements that approximately align in 3D with the head motion axis encoded by the implant.TRIAL REGISTRATIONClinicalTrials.gov: NCT02725463.FUNDINGNIH/National Institute on Deafness and Other Communication Disorders: R01DC013536 and 2T32DC000023; Labyrinth Devices, LLC; and Med-El GmbH.
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Affiliation(s)
| | - Desi P Schoo
- Department of Otolaryngology - Head & Neck Surgery, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Mehdi Rahman
- Labyrinth Devices, LLC, Baltimore, Maryland, USA
| | | | | | | | | | | | | | | | | | - Gene Y Fridman
- Department of Biomedical Engineering and.,Department of Otolaryngology - Head & Neck Surgery, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | | | - Bryan K Ward
- Department of Otolaryngology - Head & Neck Surgery, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Carolina Treviño
- Department of Otolaryngology - Head & Neck Surgery, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Stephen P Bowditch
- Department of Otolaryngology - Head & Neck Surgery, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Dale C Roberts
- Department of Otolaryngology - Head & Neck Surgery, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Kelly E Lane
- Department of Otolaryngology - Head & Neck Surgery, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Yoav Gimmon
- Department of Otolaryngology - Head & Neck Surgery, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Michael C Schubert
- Department of Otolaryngology - Head & Neck Surgery, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - John P Carey
- Department of Otolaryngology - Head & Neck Surgery, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | | | - Charles C Della Santina
- Department of Biomedical Engineering and.,Department of Otolaryngology - Head & Neck Surgery, Johns Hopkins School of Medicine, Baltimore, Maryland, USA.,Labyrinth Devices, LLC, Baltimore, Maryland, USA
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Virtual Rhesus Labyrinth Model Predicts Responses to Electrical Stimulation Delivered by a Vestibular Prosthesis. J Assoc Res Otolaryngol 2019; 20:313-339. [PMID: 31165284 DOI: 10.1007/s10162-019-00725-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Accepted: 05/08/2019] [Indexed: 10/26/2022] Open
Abstract
To better understand the spread of prosthetic current in the inner ear and to facilitate design of electrode arrays and stimulation protocols for a vestibular implant system intended to restore sensation after loss of vestibular hair cell function, we created a model of the primate labyrinth. Because the geometry of the implanted ear is complex, accurately modeling effects of prosthetic stimuli on vestibular afferent activity required a detailed representation of labyrinthine anatomy. Model geometry was therefore generated from three-dimensional (3D) reconstructions of a normal rhesus temporal bone imaged using micro-MRI and micro-CT. For systematically varied combinations of active and return electrode location, the extracellular potential field during a biphasic current pulse was computed using finite element methods. Potential field values served as inputs to stochastic, nonlinear dynamic models for each of 2415 vestibular afferent axons, each with unique origin on the neuroepithelium and spiking dynamics based on a modified Smith and Goldberg model. We tested the model by comparing predicted and actual 3D vestibulo-ocular reflex (VOR) responses for eye rotation elicited by prosthetic stimuli. The model was individualized for each implanted animal by placing model electrodes in the standard labyrinth geometry based on CT localization of actual implanted electrodes. Eye rotation 3D axes were predicted from relative proportions of model axons excited within each of the three ampullary nerves, and predictions were compared to archival eye movement response data measured in three alert rhesus monkeys using 3D scleral coil oculography. Multiple empirically observed features emerged as properties of the model, including effects of changing active and return electrode position. The model predicts improved prosthesis performance when the reference electrode is in the labyrinth's common crus (CC) rather than outside the temporal bone, especially if the reference electrode is inserted nearly to the junction of the CC with the vestibule. Extension of the model to human anatomy should facilitate optimal design of electrode arrays for clinical application.
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Khan SI, Della Santina CC, Migliaccio AA. Angular vestibuloocular reflex responses in Otop1 mice. II. Otolith sensor input improves compensation after unilateral labyrinthectomy. J Neurophysiol 2019; 121:2300-2307. [DOI: 10.1152/jn.00812.2018] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
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.
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Affiliation(s)
- Serajul I. Khan
- Balance and Vision Laboratory, Neuroscience Research Australia, Sydney, New South Wales, Australia
- University of New South Wales, Sydney, New South Wales, Australia
| | - Charles C. Della Santina
- Department of Otolaryngology—Head and Neck Surgery, Johns Hopkins University, Baltimore, Maryland
| | - Americo A. Migliaccio
- Balance and Vision Laboratory, Neuroscience Research Australia, Sydney, New South Wales, Australia
- University of New South Wales, Sydney, New South Wales, Australia
- Department of Otolaryngology—Head and Neck Surgery, Johns Hopkins University, Baltimore, Maryland
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Marques PS, Dias CC, Perez-Fernandez N, Spratley J. Instrumental head impulse test changes after intratympanic gentamicin for unilateral definite Ménière's disease: A systematic review and meta-analysis. Auris Nasus Larynx 2018; 45:943-951. [PMID: 29402608 DOI: 10.1016/j.anl.2018.01.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2017] [Revised: 12/18/2017] [Accepted: 01/10/2018] [Indexed: 11/27/2022]
Abstract
OBJECTIVE To estimate how much could intratympanic gentamicin (ITG) interfere with the vestibular-ocular reflex (VOR) parameters on instrumental head impulse test (HIT), either with scleral search coil or video head impulse test and, eventually, foresee the control of vertigo crisis in unilateral intractable Ménière's disease (MD). METHODS A literature search was conducted in PubMed, Scopus, Web of Science and Cochrane search engines. The search terms used were "vestibular ocular reflex", "head impulse test", "gentamicin," and "Meniere's disease". Limitations included text availability to be full text, species to be humans and language to be English. All study types were included. 89 articles were screened identifying four eligible studies were identified. Studies were included after consensus of the authors. Meta-analysis was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Data was analysed using Review Manager software. RESULTS Instrumental HIT, after ITG for MD, demonstrated, in the treated ear, a decreased gain in the horizontal, posterior and superior semicircular canals (SCC), of 0.36 (0.26; 0.47; 95% CI), 0.35 (0.22; 0.48; 95% CI) and 0.28 (0.21; 0.35; 95% CI), respectively. Gain asymmetry increases between the treated and non-treated ear of 23.78 (7.22; 40.35; 95% CI), 32.01 (12.27; 51.76; 95% CI) and 17.49 (9.99; 24.99; 95% CI), were similarly detected in the horizontal, posterior and superior SCC, respectively. Significantly smaller gain values after the first treatment were observed for a single injection group versus multiple injection group in the horizontal (p=0.002) and superior SCCs (p=0.016). CONCLUSIONS Instrumental HIT is effective in evaluating the SCC function after ITG for intractable unilateral MD. VOR gain changes in the direction of the treated ear in the three SCC have been clearly registered. An increased reduction of the VOR gain in the horizontal and anterior SCC also seemed to foresee the control of vertigo crisis. Still, after meta-analysis, the small number of patients' data available did not allow to define a treatment end-point value. This review also indicated that further and better-designed studies are warranted.
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Affiliation(s)
- Pedro Santos Marques
- Department of Otorhinolaryngology, S. João Hospital Centre, Alameda Prof. Hernâni Monteiro, Porto, Portugal; Department of Surgery and Physiology/Otorhinolaryngology, Faculty of Medicine, University of Porto, Alameda Prof. Hernâni Monteiro, Porto, Portugal.
| | - Claudia Camila Dias
- Department of Community Medicine, Information and Health Decision Sciences, Faculty of Medicine, University of Porto, Alameda Prof. Hernâni Monteiro, Porto, Portugal; Center for Health Technology and Services Research (CINTESIS), Faculty of Medicine, University of Porto, Alameda Prof. Hernâni Monteiro, Porto, Portugal
| | - Nicolas Perez-Fernandez
- Department of Otorhinolaryngology, Clinica Universidad Navarra, University of Navarra, Pamplona, Spain
| | - Jorge Spratley
- Department of Otorhinolaryngology, S. João Hospital Centre, Alameda Prof. Hernâni Monteiro, Porto, Portugal; Department of Surgery and Physiology/Otorhinolaryngology, Faculty of Medicine, University of Porto, Alameda Prof. Hernâni Monteiro, Porto, Portugal; Center for Health Technology and Services Research (CINTESIS), Faculty of Medicine, University of Porto, Alameda Prof. Hernâni Monteiro, Porto, Portugal
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Shepherd RK, Villalobos J, Burns O, Nayagam DAX. The development of neural stimulators: a review of preclinical safety and efficacy studies. J Neural Eng 2018; 15:041004. [PMID: 29756600 PMCID: PMC6049833 DOI: 10.1088/1741-2552/aac43c] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
OBJECTIVE Given the rapid expansion of the field of neural stimulation and the rigorous regulatory approval requirements required before these devices can be applied clinically, it is important that there is clarity around conducting preclinical safety and efficacy studies required for the development of this technology. APPROACH The present review examines basic design principles associated with the development of a safe neural stimulator and describes the suite of preclinical safety studies that need to be considered when taking a device to clinical trial. MAIN RESULTS Neural stimulators are active implantable devices that provide therapeutic intervention, sensory feedback or improved motor control via electrical stimulation of neural or neuro-muscular tissue in response to trauma or disease. Because of their complexity, regulatory bodies classify these devices in the highest risk category (Class III), and they are therefore required to go through a rigorous regulatory approval process before progressing to market. The successful development of these devices is achieved through close collaboration across disciplines including engineers, scientists and a surgical/clinical team, and the adherence to clear design principles. Preclinical studies form one of several key components in the development pathway from concept to product release of neural stimulators. Importantly, these studies provide iterative feedback in order to optimise the final design of the device. Key components of any preclinical evaluation include: in vitro studies that are focussed on device reliability and include accelerated testing under highly controlled environments; in vivo studies using animal models of the disease or injury in order to assess efficacy and, given an appropriate animal model, the safety of the technology under both passive and electrically active conditions; and human cadaver and ex vivo studies designed to ensure the device's form factor conforms to human anatomy, to optimise the surgical approach and to develop any specialist surgical tooling required. SIGNIFICANCE The pipeline from concept to commercialisation of these devices is long and expensive; careful attention to both device design and its preclinical evaluation will have significant impact on the duration and cost associated with taking a device through to commercialisation. Carefully controlled in vitro and in vivo studies together with ex vivo and human cadaver trials are key components of a thorough preclinical evaluation of any new neural stimulator.
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Affiliation(s)
- Robert K Shepherd
- Bionics Institute, East Melbourne, Australia. Medical Bionics Department, University of Melbourne, Melbourne, Australia
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Hermann R, Ionescu EC, Dumas O, Tringali S, Truy E, Tilikete C. Bilateral Vestibulopathy: Vestibular Function, Dynamic Visual Acuity and Functional Impact. Front Neurol 2018; 9:555. [PMID: 30042725 PMCID: PMC6048872 DOI: 10.3389/fneur.2018.00555] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 06/20/2018] [Indexed: 11/16/2022] Open
Abstract
Introduction: Patients suffering from bilateral vestibular hypofunction (BVH) often experience ataxia as well as visual instability. Even though progress has been made in vestibular testing, insights regarding vestibular deficit in BVH remain incomplete since no method allows evaluation of frequency ranges of vestibular sensors in a continuous way. The aim of our study was to give a detailed description of the level of vestibular deficit in different ranges of vestibular stimulation and an exhaustive evaluation of the functional impact including dynamic visual acuity (DVA) in a cohort of BVH patients in different etiologies. Methods: We prospectively included 20 patients with chronic BVH. All patients underwent clinical evaluation and functional assessment including evaluation of their symptoms related to BVH, quality of life questionnaire and DVA in the horizontal and vertical plane. Patients underwent vestibulo-ocular reflex (VOR) testing using rotatory chair, caloric stimulation and video head impulse (vHIT) in the plane of the 6 canals, and cervical and ocular Vestibular evoked myogenic potentials. Results: Mean rotatory VOR gain was 0.07 (SD = 0.07). Mean rotatory VOR gain during vHIT for the lateral, anterior and posterior canals was respectively < 0.28, < 0.34, and < 0.20. Mean loss of DVA in the 4 directions was >0.30 LogMAR. In our population fall frequency was significantly higher in patients with lower UniPedal Stance Test (UPST), higher Dizziness Handicap Inventory and Ataxia Numeric Scale (ANS) scores, as well as greater loss of upwards DVA. Patients with ototoxic BVH had a significantly higher residual VOR gain during vHIT in the anterior canal plane and lower DHI than other patients. In the general population anterior canal function was significantly higher than lateral or posterior canal function. Conclusions: This study gives extensive descriptive results of residual vestibular function, DVA and quality of life in a population of patients suffering from severe BVH. UPST and ANS are good indicators for fall risk in case of BVH. Gentamicin induced BVH seems to have a lesser impact on quality of life than other etiologies.Anterior semi-circular canal function seems less deteriorated than lateral and posterior function.
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Affiliation(s)
- Ruben Hermann
- ENT and Cervico-Facial Surgery Department, Hôpital Edouard Herriot, Hospices Civils de Lyon, Lyon, France.,INSERM U1028, CNRS UMR5292, Lyon Neuroscience Research Center, Equipe IMPACT, Lyon, France.,University Lyon 1, Lyon, France
| | - Eugen C Ionescu
- Department of Audiology and Otoneurological Evaluation, Hôpital Edouard Herriot, Hospices Civils de Lyon, Lyon, France
| | - Olivier Dumas
- Société Française de Kinésithérapie Vestibulaire, Lyon, France
| | - Stephane Tringali
- University Lyon 1, Lyon, France.,Department of Otology and Otoneurology, Hôpital Lyon Sud, Hospice Civils de Lyon, Lyon, France
| | - Eric Truy
- ENT and Cervico-Facial Surgery Department, Hôpital Edouard Herriot, Hospices Civils de Lyon, Lyon, France.,INSERM U1028, CNRS UMR5292, Lyon Neuroscience Research Center, Equipe IMPACT, Lyon, France.,University Lyon 1, Lyon, France
| | - Caroline Tilikete
- INSERM U1028, CNRS UMR5292, Lyon Neuroscience Research Center, Equipe IMPACT, Lyon, France.,University Lyon 1, Lyon, France.,Neuro-Ophthalmology Unit, Hopital Neurologique et Neurochirurgical P Wertheimer, Hospices Civils de Lyon, Lyon, France
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Johnson Chacko L, Schmidbauer DT, Handschuh S, Reka A, Fritscher KD, Raudaschl P, Saba R, Handler M, Schier PP, Baumgarten D, Fischer N, Pechriggl EJ, Brenner E, Hoermann R, Glueckert R, Schrott-Fischer A. Analysis of Vestibular Labyrinthine Geometry and Variation in the Human Temporal Bone. Front Neurosci 2018. [PMID: 29535601 PMCID: PMC5834493 DOI: 10.3389/fnins.2018.00107] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Stable posture and body movement in humans is dictated by the precise functioning of the ampulla organs in the semi-circular canals. Statistical analysis of the interrelationship between bony and membranous compartments within the semi-circular canals is dependent on the visualization of soft tissue structures. Thirty-one human inner ears were prepared, post-fixed with osmium tetroxide and decalcified for soft tissue contrast enhancement. High resolution X-ray microtomography images at 15 μm voxel-size were manually segmented. This data served as templates for centerline generation and cross-sectional area extraction. Our estimates demonstrate the variability of individual specimens from averaged centerlines of both bony and membranous labyrinth. Centerline lengths and cross-sectional areas along these lines were identified from segmented data. Using centerlines weighted by the inverse squares of the cross-sectional areas, plane angles could be quantified. The fit planes indicate that the bony labyrinth resembles a Cartesian coordinate system more closely than the membranous labyrinth. A widening in the membranous labyrinth of the lateral semi-circular canal was observed in some of the specimens. Likewise, the cross-sectional areas in the perilymphatic spaces of the lateral canal differed from the other canals. For the first time we could precisely describe the geometry of the human membranous labyrinth based on a large sample size. Awareness of the variations in the canal geometry of the membranous and bony labyrinth would be a helpful reference in designing electrodes for future vestibular prosthesis and simulating fluid dynamics more precisely.
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Affiliation(s)
- Lejo Johnson Chacko
- Department of Otolaryngology, Medical University of Innsbruck, Innsbruck, Austria
| | - Dominik T Schmidbauer
- Department of Otolaryngology, Medical University of Innsbruck, Innsbruck, Austria.,Department of Biotechnology & Food Engineering, Management Center Innsbruck, Innsbruck, Austria
| | - Stephan Handschuh
- VetImaging, VetCore Facility for Research, University of Veterinary Medicine, Vienna, Austria
| | - Alen Reka
- Department of Otolaryngology, Medical University of Innsbruck, Innsbruck, Austria
| | - Karl D Fritscher
- Institute of Biomedical Image Analysis, UMIT, Hall in Tirol, Austria
| | - Patrik Raudaschl
- Institute of Biomedical Image Analysis, UMIT, Hall in Tirol, Austria
| | | | - Michael Handler
- Institute of Electrical and Biomedical Engineering, UMIT, Hall in Tirol, Austria
| | - Peter P Schier
- Institute of Electrical and Biomedical Engineering, UMIT, Hall in Tirol, Austria
| | - Daniel Baumgarten
- Institute of Electrical and Biomedical Engineering, UMIT, Hall in Tirol, Austria.,Institute of Biomedical Engineering and Informatics, Technische Universität Ilmenau, Ilmenau, Germany
| | - Natalie Fischer
- Department of Otolaryngology, Medical University of Innsbruck, Innsbruck, Austria
| | - Elisabeth J Pechriggl
- Division of Clinical and Functional Anatomy, Department of Anatomy, Histology and Embryology, Medical University of Innsbruck, Innsbruck, Austria
| | - Erich Brenner
- Division of Clinical and Functional Anatomy, Department of Anatomy, Histology and Embryology, Medical University of Innsbruck, Innsbruck, Austria
| | - Romed Hoermann
- Division of Clinical and Functional Anatomy, Department of Anatomy, Histology and Embryology, Medical University of Innsbruck, Innsbruck, Austria
| | - Rudolf Glueckert
- Department of Otolaryngology, Medical University of Innsbruck, Innsbruck, Austria.,University Clinics Innsbruck, Tirol Kliniken, Innsbruck, Austria
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Intratympanic (IT) Therapies for Menière's Disease: Some Consensus Among the Confusion. CURRENT OTORHINOLARYNGOLOGY REPORTS 2017; 5:132-141. [PMID: 29568697 DOI: 10.1007/s40136-017-0153-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Purpose of Review Aminoglycosides and corticosteroids are commonly used to treat Menière's disease. Intratympanic (IT) administration of these medications allows high inner ear concentrations without significant adverse systemic effects. As a direct result, IT therapy has grown in popularity. Recent studies have compared patient outcomes between IT aminoglycosides and corticosteroids. This review summarizes these findings. Recent Findings Trials comparing IT corticosteroids to IT placebo or oral therapy have had conflicting results. Most recently, Lambert et al. investigated the effect of IT dexamethasone in a sustained-release formulation compared to placebo. Their findings demonstrated improvement in some secondary measures of vertigo with the sustained-release formulation.IT gentamicin is known to be effective in controlling vertigo in Menière's disease. In a recent study from 2016, Patel et al compared IT gentamicin and IT methylprednisolone in a double-blind, randomized controlled trial and identified no significant differences between the two in vertigo control. Summary IT injections of aminoglycosides and corticosteroids can improve vertigo control. Hearing and vestibular loss however may result with IT aminoglycosides. Corticosteroids demonstrate limited hearing loss but may not have the same efficacy in controlling vertigo. Further investigation in the etiology of Menière's disease is needed to tailor the proposed treatment to suit the disease mechanism.
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Burns JC, Stone JS. Development and regeneration of vestibular hair cells in mammals. Semin Cell Dev Biol 2017; 65:96-105. [PMID: 27864084 PMCID: PMC5423856 DOI: 10.1016/j.semcdb.2016.11.001] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Accepted: 11/03/2016] [Indexed: 10/20/2022]
Abstract
Vestibular sensation is essential for gaze stabilization, balance, and perception of gravity. The vestibular receptors in mammals, Type I and Type II hair cells, are located in five small organs in the inner ear. Damage to hair cells and their innervating neurons can cause crippling symptoms such as vertigo, visual field oscillation, and imbalance. In adult rodents, some Type II hair cells are regenerated and become re-innervated after damage, presenting opportunities for restoring vestibular function after hair cell damage. This article reviews features of vestibular sensory cells in mammals, including their basic properties, how they develop, and how they are replaced after damage. We discuss molecules that control vestibular hair cell regeneration and highlight areas in which our understanding of development and regeneration needs to be deepened.
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Affiliation(s)
- Joseph C Burns
- Decibel Therapeutics, 215 First St., Suite 430, Cambridge, MA 02142, USA.
| | - Jennifer S Stone
- Department of Otolaryngology/Head and Neck Surgery and The Virginia Merrill Bloedel Hearing Research Center, University of Washington School of Medicine, Box 357923, Seattle, WA 98195-7923, USA.
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Plasticity within excitatory and inhibitory pathways of the vestibulo-spinal circuitry guides changes in motor performance. Sci Rep 2017; 7:853. [PMID: 28405011 PMCID: PMC5429812 DOI: 10.1038/s41598-017-00956-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Accepted: 03/20/2017] [Indexed: 11/09/2022] Open
Abstract
Investigations of behaviors with well-characterized circuitry are required to understand how the brain learns new motor skills and ensures existing behaviors remain appropriately calibrated over time. Accordingly, here we recorded from neurons within different sites of the vestibulo-spinal circuitry of behaving macaque monkeys during temporally precise activation of vestibular afferents. Behaviorally relevant patterns of vestibular nerve activation generated a rapid and substantial decrease in the monosynaptic responses recorded at the first central stage of processing from neurons receiving direct input from vestibular afferents within minutes, as well as a decrease in the compensatory reflex response that lasted up to 8 hours. In contrast, afferent responses to this same stimulation remained constant, indicating that plasticity was not induced at the level of the periphery but rather at the afferent-central neuron synapse. Strikingly, the responses of neurons within indirect brainstem pathways also remained constant, even though the efficacy of their central input was significantly reduced. Taken together, our results show that rapid plasticity at the first central stage of vestibulo-spinal pathways can guide changes in motor performance, and that complementary plasticity on the same millisecond time scale within inhibitory vestibular nuclei networks contributes to ensuring a relatively robust behavioral output.
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Nguyen TAK, DiGiovanna J, Cavuscens S, Ranieri M, Guinand N, van de Berg R, Carpaneto J, Kingma H, Guyot JP, Micera S, Fornos AP. Characterization of pulse amplitude and pulse rate modulation for a human vestibular implant during acute electrical stimulation. J Neural Eng 2016; 13:046023. [DOI: 10.1088/1741-2560/13/4/046023] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Rabbitt RD, Brichta AM, Tabatabaee H, Boutros PJ, Ahn J, Della Santina CC, Poppi LA, Lim R. Heat pulse excitability of vestibular hair cells and afferent neurons. J Neurophysiol 2016; 116:825-43. [PMID: 27226448 DOI: 10.1152/jn.00110.2016] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Accepted: 05/24/2016] [Indexed: 11/22/2022] Open
Abstract
In the present study we combined electrophysiology with optical heat pulse stimuli to examine thermodynamics of membrane electrical excitability in mammalian vestibular hair cells and afferent neurons. We recorded whole cell currents in mammalian type II vestibular hair cells using an excised preparation (mouse) and action potentials (APs) in afferent neurons in vivo (chinchilla) in response to optical heat pulses applied to the crista (ΔT ≈ 0.25°C per pulse). Afferent spike trains evoked by heat pulse stimuli were diverse and included asynchronous inhibition, asynchronous excitation, and/or phase-locked APs synchronized to each infrared heat pulse. Thermal responses of membrane currents responsible for APs in ganglion neurons were strictly excitatory, with Q10 ≈ 2. In contrast, hair cells responded with a mix of excitatory and inhibitory currents. Excitatory hair cell membrane currents included a thermoelectric capacitive current proportional to the rate of temperature rise (dT/dt) and an inward conduction current driven by ΔT An iberiotoxin-sensitive inhibitory conduction current was also evoked by ΔT, rising in <3 ms and decaying with a time constant of ∼24 ms. The inhibitory component dominated whole cell currents in 50% of hair cells at -68 mV and in 67% of hair cells at -60 mV. Responses were quantified and described on the basis of first principles of thermodynamics. Results identify key molecular targets underlying heat pulse excitability in vestibular sensory organs and provide quantitative methods for rational application of optical heat pulses to examine protein biophysics and manipulate cellular excitability.
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Affiliation(s)
- Richard D Rabbitt
- Departments of Bioengineering and Otolaryngology, University of Utah, Salt Lake City, Utah;
| | - Alan M Brichta
- School of Biomedical Sciences and Pharmacy, University of Newcastle, Callaghan, New South Wales, Australia; and
| | - Hessam Tabatabaee
- School of Biomedical Sciences and Pharmacy, University of Newcastle, Callaghan, New South Wales, Australia; and
| | - Peter J Boutros
- Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins School of Medicine, Baltimore, Maryland
| | - JoongHo Ahn
- Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins School of Medicine, Baltimore, Maryland
| | - Charles C Della Santina
- Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins School of Medicine, Baltimore, Maryland
| | - Lauren A Poppi
- School of Biomedical Sciences and Pharmacy, University of Newcastle, Callaghan, New South Wales, Australia; and
| | - Rebecca Lim
- School of Biomedical Sciences and Pharmacy, University of Newcastle, Callaghan, New South Wales, Australia; and
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