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Han D, Carr CE. Central projections of auditory nerve fibers in the western rat snake (Pantherophis obsoletus). J Comp Neurol 2023; 531:1261-1273. [PMID: 37245999 PMCID: PMC10590474 DOI: 10.1002/cne.25495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 04/24/2023] [Accepted: 04/27/2023] [Indexed: 05/30/2023]
Abstract
Despite the absence of tympanic middle ears, snakes can hear. They are thought to primarily detect substrate vibration via connections between the lower jaw and the inner ear. We used the western rat snake (Pantherophis obsoletus) to determine how vibration is processed in the brain. We measured vibration-evoked potential recordings to reveal sensitivity to low-frequency vibrations. We then used tract tracing combined with immunohistochemistry and Nissl staining to describe the central projections of the papillar branch of the VIIIth nerve. Applications of biotinylated dextran amine to the basilar papilla (homologous to the organ of Corti of mammals) labeled bouton-like terminals in two first-order cochlear nuclei, a rostrolateral nucleus angularis (NA) and a caudomedial nucleus magnocellularis (NM). NA formed a distinct dorsal eminence, consisted of heterogenous cell types, and was parvalbumin positive. NM was smaller and poorly separated from the surrounding vestibular nuclei. NM was distinguished by positive calbindin label and included fusiform and round cells. Thus, the atympanate western rat snake shares similar first-order projections to tympanate reptiles. Auditory pathways may be used for detecting vibration, not only in snakes but also potentially in atympanate early tetrapods.
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Affiliation(s)
- Dawei Han
- Department of Biology, University of Maryland, College Park, MD, USA
- Neuroscience and Cognitive Science Program, University of Maryland, College Park, MD, USA
| | - Catherine E. Carr
- Department of Biology, University of Maryland, College Park, MD, USA
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Burghard AL, Lee CM, Fabrizio-Stover EM, Oliver DL. Long-Duration Sound-Induced Facilitation Changes Population Activity in the Inferior Colliculus. Front Syst Neurosci 2022; 16:920642. [PMID: 35873097 PMCID: PMC9301083 DOI: 10.3389/fnsys.2022.920642] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Accepted: 06/03/2022] [Indexed: 11/13/2022] Open
Abstract
The inferior colliculus (IC) is at the midpoint of the auditory system and integrates virtually all information ascending from the auditory brainstem, organizes it, and transmits the results to the auditory forebrain. Its abundant, excitatory local connections are crucial for this task. This study describes a long duration sound (LDS)-induced potentiation in the IC that changes both subsequent tone-evoked responses and spontaneous activity. Afterdischarges, changes of spontaneous spiking following an LDS, were seen previously in single neurons. Here, we used multi-channel probes to record activity before and after a single, tetanic sound and describe the changes in a population of IC neurons. Following a 60 s narrowband-noise stimulation, a subset of recording channels (∼16%) showed afterdischarges. A facilitated response spike rate to tone pips following an LDS was also observed in ∼16% of channels. Both channels with an afterdischarge and channels with facilitated tone responses had higher firing rates in response to LDS, and the magnitude of the afterdischarges increased with increased responses to the LDS. This is the first study examining the effect of LDS stimulation on tone-evoked responses. This observed facilitation in vivo has similarities to post-tetanic potentiation in vitro as both manner of induction (strong stimulation for several seconds) as well as time-course of the facilitation (second to minute range) are comparable. Channels with and without facilitation appear to be intermixed and distributed widely in the central nucleus of IC, and this suggests a heretofore unknown property of some IC neurons or their circuits. Consequently, this sound-evoked facilitation may enhance the sound-evoked output of these neurons, while, simultaneously, most other IC neurons have reduced or unchanged output in response to the same stimulus.
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Verdoodt D, Eens S, Van Dam D, De Deyn PP, Vanderveken OM, Szewczyk K, Saldien V, Ponsaerts P, Van Rompaey V. Effect of Oral Allylnitrile Administration on Cochlear Functioning in Mice Following Comparison of Different Anesthetics for Hearing Assessment. FRONTIERS IN TOXICOLOGY 2021; 3:641569. [PMID: 35295154 PMCID: PMC8915850 DOI: 10.3389/ftox.2021.641569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 02/03/2021] [Indexed: 11/13/2022] Open
Abstract
Background: Allylnitrile is a compound found in cruciferous vegetables and has the same lethality and toxic effects as the other nitriles. In 2013, a viable allylnitrile ototoxicity mouse model was established. The toxicity of allylnitrile was limited through inhibition of CYP2E1 with trans-1,2-dichloroethylene (TDCE). The allylnitrile intoxication model has been extensively tested in the 129S1 mouse strain for vestibular function, which showed significant HC loss in the vestibular organ accompanied by severe behavioral abnormalities. However, the effect of allylnitrile on auditory function remains to be evaluated. Commonly used anesthetics to conduct hearing measurements are isoflurane and ketamine/xylazine anesthesia but the effect of these anesthetics on hearing assessment is still unknown. In this study we will evaluate the otovestibular effects of oral allylnitrile administration in mice. In addition, we will compare the influence of isoflurane and ketamine/xylazine anesthesia on hearing thresholds.Methods and Materials: Fourteen Coch+/– CBACa mice were randomly allocated into an allylnitrile (n = 8) and a control group (n = 6). Baseline measurements were done with isoflurane and 1 week later under ketamine/xylazine anesthesia. After baseline audiovestibular measurements, mice were co-administered with a single dose of allylnitrile and, to reduce systemic toxicity, three intraperitoneal injections of TDCE were given. Hearing loss was evaluated by recordings of auditory brainstem responses (ABR) and distortion product otoacoustic emissions (DPOAE). Specific behavioral test batteries for vestibular function were used to assess alterations in vestibular function.Results: Hearing thresholds were significantly elevated when using isoflurane anesthesia compared to ketamine/xylazine anesthesia for all frequencies of the ABR and the mid-to-high frequencies in DPOAE. Allylnitrile-treated mice lacked detectable ABR thresholds at each frequency tested, while DPOAE thresholds were significantly elevated in the low-frequency region of the cochlea and completely lacking in the mid-to high frequency region. Vestibular function was not affected by allylnitrile administration.Conclusion: Isoflurane anesthesia has a negative confounding effect on the measurement of hearing thresholds in mice. A single oral dose of allylnitrile induced hearing loss but did not significantly alter vestibular function in mice. This is the first study to show that administration of allylnitrile can cause a complete loss of hearing function in mice.
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Affiliation(s)
- Dorien Verdoodt
- Department of Translational Neurosciences, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium
- Laboratory of Experimental Hematology, Faculty of Medicine and Health Sciences, Vaccine and Infectious Disease Institute (Vaxinfectio), University of Antwerp, Antwerp, Belgium
- *Correspondence: Dorien Verdoodt
| | - Sander Eens
- Department of Translational Neurosciences, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium
| | - Debby Van Dam
- Laboratory of Neurochemistry and Behaviour, Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, University of Antwerp, Antwerp, Belgium
- Department of Neurology and Alzheimer Research Center, University of Groningen and University Medical Center Groningen, Groningen, Netherlands
| | - Peter Paul De Deyn
- Laboratory of Neurochemistry and Behaviour, Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, University of Antwerp, Antwerp, Belgium
- Department of Neurology and Alzheimer Research Center, University of Groningen and University Medical Center Groningen, Groningen, Netherlands
- Department of Neurology, Memory Clinic of Hospital Network Antwerp (ZNA) Middelheim and Hoge Beuken, Antwerp, Belgium
| | - Olivier M. Vanderveken
- Department of Translational Neurosciences, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium
- Department of Otorhinolaryngology and Head and Neck Surgery, Antwerp University Hospital, Edegem, Belgium
| | - Krystyna Szewczyk
- Department of Translational Neurosciences, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium
| | - Vera Saldien
- Department of Anaesthesiology, Antwerp University Hospital, Edegem, Belgium
| | - Peter Ponsaerts
- Laboratory of Experimental Hematology, Faculty of Medicine and Health Sciences, Vaccine and Infectious Disease Institute (Vaxinfectio), University of Antwerp, Antwerp, Belgium
| | - Vincent Van Rompaey
- Department of Translational Neurosciences, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium
- Department of Otorhinolaryngology and Head and Neck Surgery, Antwerp University Hospital, Edegem, Belgium
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Effect of Depth of Total Intravenous General Anesthesia on Intraoperative Electrically Evoked Compound Action Potentials in Cochlear Implantation Surgery. Anesthesiol Res Pract 2019; 2019:6838506. [PMID: 31885553 PMCID: PMC6914979 DOI: 10.1155/2019/6838506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 10/20/2019] [Accepted: 11/14/2019] [Indexed: 11/21/2022] Open
Abstract
Purpose This study aims to compare the effect of the depth of total intravenous anesthesia (TIVA) on intraoperative electrically evoked compound action potential (e-ECAP) thresholds in cochlear implant operations. Methods Prospectively, a total of 39 patients aged between 1 and 48 years who were scheduled to undergo cochlear implantation surgeries were enrolled in this study. Every patient received both light and deep TIVA during the cochlear implant surgery. The e-ECAP thresholds were obtained during the light and deep TIVA. Results After comparing the e-ECAP means for each electrode (lead) between the light and deep anesthesia, no significant differences were detected between the light and deep anesthesia. Conclusion The depth of TIVA may have no significant influence on the e-ECAP thresholds as there was no statistical difference between the light and deep anesthesia.
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Naert G, Pasdelou MP, Le Prell CG. Use of the guinea pig in studies on the development and prevention of acquired sensorineural hearing loss, with an emphasis on noise. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2019; 146:3743. [PMID: 31795705 PMCID: PMC7195866 DOI: 10.1121/1.5132711] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 07/30/2019] [Accepted: 08/12/2019] [Indexed: 05/10/2023]
Abstract
Guinea pigs have been used in diverse studies to better understand acquired hearing loss induced by noise and ototoxic drugs. The guinea pig has its best hearing at slightly higher frequencies relative to humans, but its hearing is more similar to humans than the rat or mouse. Like other rodents, it is more vulnerable to noise injury than the human or nonhuman primate models. There is a wealth of information on auditory function and vulnerability of the inner ear to diverse insults in the guinea pig. With respect to the assessment of potential otoprotective agents, guinea pigs are also docile animals that are relatively easy to dose via systemic injections or gavage. Of interest, the cochlea and the round window are easily accessible, notably for direct cochlear therapy, as in the chinchilla, making the guinea pig a most relevant and suitable model for hearing. This article reviews the use of the guinea pig in basic auditory research, provides detailed discussion of its use in studies on noise injury and other injuries leading to acquired sensorineural hearing loss, and lists some therapeutics assessed in these laboratory animal models to prevent acquired sensorineural hearing loss.
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Affiliation(s)
| | | | - Colleen G Le Prell
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Dallas, Texas 75080, USA
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Luo J, Simmons AM, Beck QM, Macías S, Moss CF, Simmons JA. Frequency-modulated up-chirps produce larger evoked responses than down-chirps in the big brown bat auditory brainstem. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2019; 146:1671. [PMID: 31590554 DOI: 10.1121/1.5126022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Accepted: 08/22/2019] [Indexed: 06/10/2023]
Abstract
In many mammals, upward-sweeping frequency-modulated (FM) sounds (up-chirps) evoke larger auditory brainstem responses than downward-sweeping sounds (down-chirps). To determine if similar effects occur in FM echolocating bats, auditory evoked responses (AERs) in big brown bats in response to up-chirps and down-chirps at different chirp durations and levels were recorded. Even though down-chirps are the biologically relevant stimulus for big brown bats, up-chirps typically evoked larger peaks in the AER, but with some exceptions at the shortest chirp durations. The up-chirp duration that produced the largest AERs and the greatest differences between up-chirps and down-chirps varied between individual bats and stimulus levels. Cross-covariance analyses using the entire AER waveform confirmed that amplitudes were typically larger to up-chirps than down-chirps at supra-threshold levels, with optimal durations around 0.5-1 ms. Changes in response latencies with stimulus levels were consistent with previous estimates of amplitude-latency trading. Latencies tended to decrease with increasing up-chirp duration and increase with increasing down-chirp duration. The effects of chirp direction on AER waveforms are generally consistent with those seen in other mammals but with small differences in response patterns that may reflect specializations for FM echolocation.
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Affiliation(s)
- Jinhong Luo
- Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, Maryland 21218, USA
| | - Andrea Megela Simmons
- Department of Cognitive, Linguistic, and Psychological Sciences, Brown University, Providence, Rhode Island 02912, USA
| | - Quincy M Beck
- Department of Neuroscience, Brown University, Providence, Rhode Island 02912, USA
| | - Silvio Macías
- Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, Maryland 21218, USA
| | - Cynthia F Moss
- Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, Maryland 21218, USA
| | - James A Simmons
- Department of Neuroscience, Brown University, Providence, Rhode Island 02912, USA
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Huang B, Yan L, Zhang Z, Yang X, Xiao Z. General anesthetic induced differential changes in latency of auditory evoked potential in the central nucleus of inferior colliculus of mouse. Neurosci Lett 2019; 708:134325. [DOI: 10.1016/j.neulet.2019.134325] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2018] [Revised: 05/31/2019] [Accepted: 06/07/2019] [Indexed: 10/26/2022]
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Burghard A, Voigt MB, Kral A, Hubka P. Categorical processing of fast temporal sequences in the guinea pig auditory brainstem. Commun Biol 2019; 2:265. [PMID: 31341964 PMCID: PMC6642126 DOI: 10.1038/s42003-019-0472-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Accepted: 05/23/2019] [Indexed: 11/21/2022] Open
Abstract
Discrimination of temporal sequences is crucial for auditory object recognition, phoneme categorization and speech understanding. The present study shows that auditory brainstem responses (ABR) to pairs of noise bursts separated by a short gap can be classified into two distinct groups based on the ratio of gap duration to initial noise burst duration in guinea pigs. If this ratio was smaller than 0.5, the ABR to the trailing noise burst was strongly suppressed. On the other hand, if the initial noise burst duration was short compared to the gap duration (a ratio greater than 0.5), a release from suppression and/or enhancement of the trailing ABR was observed. Consequently, initial noise bursts of shorter duration caused a faster transition between response classes than initial noise bursts of longer duration. We propose that the described findings represent a neural correlate of subcortical categorical preprocessing of temporal sequences in the auditory system.
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Affiliation(s)
- Alice Burghard
- Institute of Audioneurotechnology & Department of Experimental Otology, ENT Clinics, Hannover Medical School, Hannover, D-30625 Germany
- Department of Neuroscience, University of Connecticut Health Center, Farmington, CT 06030 USA
| | - Mathias Benjamin Voigt
- Institute of Audioneurotechnology & Department of Experimental Otology, ENT Clinics, Hannover Medical School, Hannover, D-30625 Germany
| | - Andrej Kral
- Institute of Audioneurotechnology & Department of Experimental Otology, ENT Clinics, Hannover Medical School, Hannover, D-30625 Germany
| | - Peter Hubka
- Institute of Audioneurotechnology & Department of Experimental Otology, ENT Clinics, Hannover Medical School, Hannover, D-30625 Germany
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Claussen AD, Vielman Quevedo R, Mostaert B, Kirk JR, Dueck WF, Hansen MR. A mouse model of cochlear implantation with chronic electric stimulation. PLoS One 2019; 14:e0215407. [PMID: 30998726 PMCID: PMC6472764 DOI: 10.1371/journal.pone.0215407] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 04/01/2019] [Indexed: 01/21/2023] Open
Abstract
Objectives Cochlear implants provide an effective treatment option for those with severe hearing loss, including those with preserved low frequency hearing. However, certain issues can reduce implant efficacy including intracochlear tissue response and delayed loss of residual acoustic hearing. We describe a mouse model of cochlear implantation with chronic electric stimulation that can be used to study cochlear implant biology and related pathologies. Methods Twelve normal hearing adult CBA/J mice underwent unilateral cochlear implantation and were evenly divided into one group receiving electric stimulation and one not. Serial impedance and neural response telemetry (NRT) measurements were made to assess implant functionality. Functionality was defined as having at least one electrode with an impedance ≤ 35 kOhms. Mouse cochleae were harvested for histology and 3D x-ray microscopy 21 days post-operatively, or, in case the implant was still functional, at a later time point when the implant failed. A separate experiment measured the hearing preservation rate in 7 adult CBA/J mice undergoing unilateral cochlear implantation with serial auditory brainstem response (ABR) and distortion product otoacoustic emissions (DPOAE). Results Implants maintained functionality for a mean of 35 days in the non-stimulated group and 19.8 days in the stimulated group. Reliable NRT and behavioral responses to electric stimulation were recorded. A robust intracochlear peri-implant tissue response with neo-ossification was seen in all cochleae. Six of seven mice maintained intact low frequency hearing up to 6 weeks following cochlear implantation. Conclusions We demonstrate the feasibility of cochlear implantation and behaviorally significant electric stimulation in the mouse, with the potential for hearing preservation. This model may be combined with established mouse models of hearing loss and the large genetic and molecular research toolkit unique to the mouse for mechanistic and therapeutic investigations of cochlear implant biology.
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Affiliation(s)
- Alexander D. Claussen
- Department of Otolaryngology-Head and Neck Surgery, University of Iowa, Iowa City, IA, United States of America
| | - René Vielman Quevedo
- Department of Otolaryngology-Head and Neck Surgery, University of Iowa, Iowa City, IA, United States of America
| | - Brian Mostaert
- Department of Otolaryngology-Head and Neck Surgery, University of Iowa, Iowa City, IA, United States of America
| | | | | | - Marlan R. Hansen
- Department of Otolaryngology-Head and Neck Surgery, University of Iowa, Iowa City, IA, United States of America
- Department of Neurosurgery, University of Iowa, Iowa City, IA, United States of America
- * E-mail:
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Gas Anesthesia Impairs Peripheral Auditory Sensitivity in Barn Owls ( Tyto alba). eNeuro 2018; 5:eN-NWR-0140-18. [PMID: 30713995 PMCID: PMC6354786 DOI: 10.1523/eneuro.0140-18.2018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 09/28/2018] [Accepted: 10/05/2018] [Indexed: 11/21/2022] Open
Abstract
Auditory nerve single-unit recordings were obtained from two groups of young barn owls (age, between posthatching days 11 and 86) in terminal experiments under two different anesthetic regimes: ketamine (6-11 mg/kg) plus xylazine (∼2 mg/kg); or isoflurane (1-1.5%) in oxygen, delivered via artificial respiration. In a second series of minimally invasive experiments, auditory brainstem responses (ABRs) were recorded in the same four adult barn owls (Tyto alba; age, between 5 and 32 months) under three different anesthetic protocols: ketamine (10 mg/kg) plus xylazine (3 mg/kg), isoflurane (1-1.5%), and sevoflurane (2-3%) in carbogen. Finally, the ABR measurements on adult owls were repeated in terminal experiments including more invasive procedures such as artificial respiration and higher isoflurane dosage. The main finding was a significant deterioration of auditory sensitivity in barn owls under gas anesthesia, at the level of the auditory nerve (i.e., a very peripheral level of the auditory system). The effect was drastic in the young animals that experienced threshold elevations in auditory nerve single-unit responses of ≥20 dB. ABR thresholds assessed repeatedly in experiments on adult owls were also significantly higher under isoflurane and sevoflurane, on average by 7 and 15 dB, compared with ketamine/xylazine. This difference already occurred with minimal dosages and was reversibly enlarged with increased isoflurane concentration. Finally, there was evidence for confounding detrimental effects associated with artificial respiration over many hours, which suggested oxygen toxicity.
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Shen X, Xiao Y, Li W, Chen K, Yu H. Sevoflurane anesthesia during pregnancy in mice induces hearing impairment in the offspring. DRUG DESIGN DEVELOPMENT AND THERAPY 2018; 12:1827-1836. [PMID: 29970957 PMCID: PMC6020999 DOI: 10.2147/dddt.s156040] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Introduction Exposure to gamma-aminobutyric acid-mimetics and N-methyl-D-aspartate-receptor antagonists during pregnancy may lead to hearing loss and long-term behavioral abnormalities in the offspring. The purpose of this study was to explore the association between prenatal exposure to sevoflurane (SEV) anesthesia and hearing impairment in mice. Materials and methods On gestational day 15, pregnant Kunming mice were exposed for 2 hours to 2.5% SEV plus 100% oxygen (anesthesia group) or 100% oxygen alone (control group). Results During auditory brainstem response testing on P30, offspring of the anesthesia group mice exhibited higher hearing thresholds at 8, 16, 24, and 32 kHz; longer peak latency of wave II at all four frequencies; and longer interpeak latencies from waves II to V at 16, 24, and 32 kHz, compared to the control offspring. Caspase-3, iNOS, and COX-2 activation occurred in the fetal cochlea of the anesthesia group. Mitochondrial swelling was observed in the anesthesia group offspring at P1 and P15. Conclusion Our results suggest that SEV exposure during pregnancy may cause detrimental effects on the developing auditory system.
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Affiliation(s)
- Xia Shen
- Department of Anesthesiology, Shanghai Eye, Ear, Nose, and Throat Hospital, Fudan University, Shanghai 200031, People's Republic of China
| | - Yanan Xiao
- Department of Anesthesiology, Shanghai Eye, Ear, Nose, and Throat Hospital, Fudan University, Shanghai 200031, People's Republic of China
| | - Wen Li
- Research Center, Shanghai Eye, Ear, Nose, and Throat Hospital, Fudan University, Shanghai 200031, People's Republic of China
| | - Kaizheng Chen
- Department of Anesthesiology, Shanghai Eye, Ear, Nose, and Throat Hospital, Fudan University, Shanghai 200031, People's Republic of China
| | - Huiqian Yu
- Department of Otorhinolaryngology, Shanghai Eye, Ear, Nose, and Throat Hospital, Fudan University, Shanghai 200031, People's Republic of China
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Sheppard AM, Zhao DL, Salvi R. Isoflurane anesthesia suppresses distortion product otoacoustic emissions in rats. J Otol 2018; 13:59-64. [PMID: 30559766 PMCID: PMC6291629 DOI: 10.1016/j.joto.2018.03.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 03/30/2018] [Indexed: 02/01/2023] Open
Abstract
A commonly used anesthetic, isoflurane, can impair auditory function in a dose-dependent manner. However, in rats, isoflurane-induced auditory impairments have only been assessed with auditory brainstem responses; a measure which is unable to distinguish if changes originate from the central or peripheral auditory system. Studies performed in other species, such as mice and guinea-pigs, suggests auditory impairment stems from disrupted OHC amplification. Despite the wide use of the rat in auditory research, these observations have yet to be replicated in the rat animal model. This study used distortion product otoacoustic emissions to assess outer hair cell function in rats that were anesthetized with either isoflurane or a ketamine/xylazine cocktail for approximately 45 min. Results indicate that isoflurane can significantly reduce DPOAE amplitudes compared to ketamine/xylazine, and that responses were more variable with isoflurane than ketamine/xylazine over the 45-min test period. Based on these observations, isoflurane should be used with caution when assessing peripheral auditory function to avoid potentially confounding effects.
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Affiliation(s)
- Adam M Sheppard
- Center for Hearing and Deafness, State University of New York at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY 14214, USA
| | - Deng-Ling Zhao
- Department of Radiology, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, Jiangsu Providence, China
| | - Richard Salvi
- Center for Hearing and Deafness, State University of New York at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY 14214, USA
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Alhowary A, EL-Radaideh K, AL-Rusan A, Hani DB, Khraise W, AL Omari A, Alzoubi F. Effect of total intravenous vs volatile anesthetics on intraoperatively acquired electrically evoked compound action potential in children undergoing cochlear implant surgery: A randomized prospective study. J Clin Anesth 2017; 36:80-83. [DOI: 10.1016/j.jclinane.2016.10.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Accepted: 10/27/2016] [Indexed: 11/29/2022]
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Cui J, Zhu B, Fang G, Smith E, Brauth SE, Tang Y. Effect of the Level of Anesthesia on the Auditory Brainstem Response in the Emei Music Frog (Babina daunchina). PLoS One 2017; 12:e0169449. [PMID: 28056042 PMCID: PMC5215878 DOI: 10.1371/journal.pone.0169449] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Accepted: 12/16/2016] [Indexed: 11/28/2022] Open
Abstract
Anesthesia is known to affect the auditory brainstem response (ABR) in mice, rats, birds and lizards. The present study investigated how the level of anesthesia affects ABR recordings in an amphibian species, Babina daunchina. To do this, we compared ABRs evoked by tone pip stimuli recorded from 35 frogs when Tricaine methane sulphonate (MS-222) anesthetic immersion times varied from 0, 5 and 10 minutes after anesthesia induction at sound frequencies between 0.5 and 6 kHz. ABR thresholds increased significantly with immersion time across the 0.5 kHz to 2.5 kHz frequency range, which is the most sensitive frequency range for hearing and the main frequency range of male calls. There were no significant differences for anesthetic levels across the 3 kHz to 6 kHz range. ABR latency was significantly longer in the 10 min group than in the 0 and 5 min groups at frequencies of 0.5, 1.0, 1.5, 2.5 kHz, while ABR latency did not differ across the 3 kHz to 4 kHz range and at 2.0 kHz. Taken together, these results show that the level of anesthesia affects the amplitude, threshold and latency of ABRs in frogs.
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Affiliation(s)
- Jianguo Cui
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, Sichuan, China
- * E-mail:
| | - Bicheng Zhu
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, Sichuan, China
| | - Guangzhan Fang
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, Sichuan, China
| | - Ed Smith
- Department of Psychology, University of Maryland, College Park, MD, United States of America
| | - Steven E. Brauth
- Department of Psychology, University of Maryland, College Park, MD, United States of America
| | - Yezhong Tang
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, Sichuan, China
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Smit AL, Lambermont VA, Stokroos RJ, Anteunis LJC, Chenault MN, Schaefer SM, Schoenmakers LWG, Kremer B, Kramer BW. Intrauterine Lipopolysaccharide-Induced Chorioamnionitis in a Sheep: Does It Affect the Auditory System? Reprod Sci 2015; 23:257-63. [PMID: 26702124 DOI: 10.1177/1933719115602759] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Fetal exposure to in utero inflammation such as chorioamnionitis is related to central nervous system injury. We hypothesized that chorioamnionitis can provoke inflammatory changes in the perilymph and alter hearing outcome. METHODS Pregnant ewes were randomized into 2 groups: intrauterine injection with lipopolysaccharide (LPS; n = 19) or saline (n = 21). In the first experiment, fetal perilymph samples were taken for cytokine analysis. In the second experiment, consecutive bone-conducted auditory brain stem responses were obtained from 1 to 7 months after birth. RESULTS Perilymph samples showed a significant elevation in interleukin 8 in the LPS group. Auditory brain stem response analysis demonstrated higher response thresholds and a prolongation of absolute peak V and interpeak intervals I to V and III to V in the LPS group compared to sham treatment. CONCLUSION Our study confirms the hypothesis that an intrauterine inflammation by LPS can result in a fetal perilymphatic inflammatory response and functional impaired hearing outcomes after birth in a sheep model.
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Affiliation(s)
- Adriana L Smit
- Department of Otorhinolaryngology, Head and Neck Surgery, Maastricht University Medical Centre, Maastricht, the Netherlands School for Mental Health and Neuroscience, Maastricht University, Maastricht, the Netherlands
| | - Verena A Lambermont
- Department of Pediatrics, Maastricht University Medical Centre, Maastricht, the Netherlands
| | - Robert J Stokroos
- Department of Otorhinolaryngology, Head and Neck Surgery, Maastricht University Medical Centre, Maastricht, the Netherlands School for Mental Health and Neuroscience, Maastricht University, Maastricht, the Netherlands
| | - Lucien J C Anteunis
- Department of Otorhinolaryngology, Head and Neck Surgery, Maastricht University Medical Centre, Maastricht, the Netherlands School for Mental Health and Neuroscience, Maastricht University, Maastricht, the Netherlands
| | - Michelene N Chenault
- Department of Otorhinolaryngology, Head and Neck Surgery, Maastricht University Medical Centre, Maastricht, the Netherlands School for Mental Health and Neuroscience, Maastricht University, Maastricht, the Netherlands Department of Methodology and Statistics, Maastricht University, Maastricht, the Netherlands
| | - Simone M Schaefer
- Department of Otorhinolaryngology, Head and Neck Surgery, Maastricht University Medical Centre, Maastricht, the Netherlands
| | - Luke W G Schoenmakers
- Department of Otorhinolaryngology, Head and Neck Surgery, Maastricht University Medical Centre, Maastricht, the Netherlands
| | - Bernd Kremer
- Department of Otorhinolaryngology, Head and Neck Surgery, Maastricht University Medical Centre, Maastricht, the Netherlands School of Oncology and Developmental Biology, Maastricht University, Maastricht, the Netherlands
| | - Boris W Kramer
- School for Mental Health and Neuroscience, Maastricht University, Maastricht, the Netherlands Department of Pediatrics, Maastricht University Medical Centre, Maastricht, the Netherlands School of Oncology and Developmental Biology, Maastricht University, Maastricht, the Netherlands
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Latency of auditory evoked potential monitoring the effects of general anesthetics on nerve fibers and synapses. Sci Rep 2015; 5:12730. [PMID: 26246365 PMCID: PMC4526847 DOI: 10.1038/srep12730] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Accepted: 07/06/2015] [Indexed: 11/24/2022] Open
Abstract
Auditory evoked potential (AEP) is an effective index for the effects of general anesthetics. However, it’s unknown if AEP can differentiate the effects of general anesthetics on nerve fibers and synapses. Presently, we investigated AEP latency and amplitude changes to different acoustic intensities during pentobarbital anesthesia. Latency more regularly changed than amplitude during anesthesia. AEP Latency monotonically decreased with acoustic intensity increase (i.e., latency-intensity curve) and could be fitted to an exponential decay equation, which showed two components, the theoretical minimum latency and stimulus-dependent delay. From the latency-intensity curves, the changes of these two components (∆L and ∆I) were extracted during anesthesia. ∆L and ∆I monitored the effect of pentobarbital on nerve fibers and synapses. Pentobarbital can induce anesthesia, and two side effects, hypoxemia and hypothermia. The hypoxemia was not related with ∆L and ∆I. However, ∆L was changed by the hypothermia, whereas ∆I was changed by the hypothermia and anesthesia. Therefore, we conclude that, AEP latency is superior to amplitude for the effects of general anesthetics, ∆L monitors the effect of hypothermia on nerve fibers, and ∆I monitors a combined effect of anesthesia and hypothermia on synapses. When eliminating the temperature factor, ∆I monitors the anesthesia effect on synapses.
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Effect of depth of general anesthesia on the threshold of electrically evoked compound action potential in cochlear implantation. Eur Arch Otorhinolaryngol 2014; 272:2697-701. [DOI: 10.1007/s00405-014-3231-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Accepted: 08/01/2014] [Indexed: 10/24/2022]
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Menardy F, Giret N, Del Negro C. The presence of an audience modulates responses to familiar call stimuli in the male zebra finch forebrain. Eur J Neurosci 2014; 40:3338-50. [PMID: 25145963 DOI: 10.1111/ejn.12696] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Revised: 06/23/2014] [Accepted: 07/15/2014] [Indexed: 12/22/2022]
Abstract
The ability to recognize familiar individuals is crucial for establishing social relationships. The zebra finch, a highly social songbird species that forms lifelong pair bonds, uses a vocalization, the distance call, to identify its mate. However, in males, this ability depends on social conditions, requiring the presence of an audience. To evaluate whether the presence of bystanders modulates the auditory processing underlying recognition abilities, we assessed, by using a lightweight telemetry system, whether electrophysiological responses driven by familiar and unfamiliar female calls in a high-level auditory area [the caudomedial nidopallium (NCM)] were modulated by the presence of conspecific males. Males had experienced the call of their mate for several months and the call of a familiar female for several days. When they were exposed to female calls in the presence of two male conspecifics, NCM neurons showed greater responses to the playback of familiar female calls, including the mate's call, than to unfamiliar ones. In contrast, no such discrimination was observed in males when they were alone or when call-evoked responses were collected under anaesthesia. Together, these results suggest that NCM neuronal activity is profoundly influenced by social conditions, providing new evidence that the properties of NCM neurons are not simply determined by the acoustic structure of auditory stimuli. They also show that neurons in the NCM form part of a network that can be shaped by experience and that probably plays an important role in the emergence of communication sound recognition.
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Affiliation(s)
- F Menardy
- CNPS, UMR CNRS 8195, University Paris-Sud, 91405, Orsay, France
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19
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Bielefeld EC. Influence of dose and duration of isoflurane anesthesia on the auditory brainstem response in the rat. Int J Audiol 2013; 53:250-8. [PMID: 24304393 DOI: 10.3109/14992027.2013.858280] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE Isoflurane anesthesia can have significant effects on processing of sounds at the peripheral and central levels, manifesting in changes in auditory-evoked potentials. The current study tested whether duration of isoflurane anesthesia changes thresholds, amplitudes, and latencies of the auditory brainstem response (ABR). DESIGN The study tested ABRs in a rat animal model under isoflurane anesthesia. Study variables were duration of isoflurane anesthesia, stimulus frequency, stimulus level, and the dose of isoflurane. Rats were anesthetized with 1.5% or 2% isoflurane. ABRs were collected from 90 to 5 dB SPL at 5-40 kHz. Three full ABR series were collected over a 105-minute period. Thresholds were assigned, and ABR wave amplitudes and latencies were measured at each stimulus frequency and level. STUDY SAMPLE Ten Sprague-Dawley rats were tested in a repeated measures design. RESULTS Statistical analyses revealed no significant effects of dose or duration on threshold, but a series of significant interactions between test variables for the amplitude and latency measurements. CONCLUSIONS In the rat, dose and duration of isoflurane anesthesia induced inconsistent changes in latency and amplitude of the ABR. At 40 kHz, isoflurane dose had more powerful effects on latency and amplitude than occurred at other frequencies.
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Affiliation(s)
- Eric C Bielefeld
- Department of Speech and Hearing Science, The Ohio State University , Columbus, Ohio , USA
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Maheras KJ, Gow A. Increased anesthesia time using 2,2,2-tribromoethanol-chloral hydrate with low impact on mouse psychoacoustics. J Neurosci Methods 2013; 219:61-9. [PMID: 23856212 DOI: 10.1016/j.jneumeth.2013.07.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Revised: 06/11/2013] [Accepted: 07/04/2013] [Indexed: 11/28/2022]
Abstract
BACKGROUND To examine psychoacoustics in mice, we have used 2,2,2-tribromoethanol anesthesia in multiple studies. We find this drug is fast-acting and yields consistent results, providing 25-30 min of anesthesia. Our recent studies in binaural hearing prompted development of a regimen to anesthesia time to 1h. We tested a novel cocktail using 2,2,2-tribromoethanol coupled with low dose chloral hydrate to extend the effective anesthesia time. NEW METHOD We have established an intraperitoneal dosing regimen for 2,2,2-tribromoethanol-chloral hydrate anesthesia. To measure efficacy of the drug cocktail, we measured auditory brainstem responses (ABRs) at 10 min intervals to determine the effects on hearing thresholds and wave amplitudes and latencies. RESULTS This novel drug combination increases effective anesthesia to 1h. ABR Wave I amplitudes, but not latencies, are marginally suppressed. Additionally, amplitudes of the centrally derived Waves III and V show significant inter-animal variability that is independent of stimulus intensity. These data argue against the systematic suppression of ABRs by the drug cocktail. COMPARISON WITH EXISTING METHODS Using 2,2,2-tribromoethanol-chloral hydrate combination in psychoacoustic studies has several advantages over other drug cocktails, the most important being preservation of latencies from centrally- and peripherally-derived ABR waves. In addition, hearing thresholds are unchanged and wave amplitudes are not systematically suppressed, although they exhibit greater variability. CONCLUSIONS We demonstrate that 375 mg/kg 2,2,2-tribromoethanol followed after 5 min by 200mg/kg chloral hydrate provides an anesthesia time of 60 min, has negligible effects on ABR wave latencies and thresholds and non-systematic effects on amplitudes.
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Affiliation(s)
- Kathleen J Maheras
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI 48201, USA
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21
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Cederholm JME, Froud KE, Wong ACY, Ko M, Ryan AF, Housley GD. Differential actions of isoflurane and ketamine-based anaesthetics on cochlear function in the mouse. Hear Res 2012; 292:71-9. [PMID: 22960466 DOI: 10.1016/j.heares.2012.08.010] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2012] [Revised: 08/13/2012] [Accepted: 08/21/2012] [Indexed: 10/28/2022]
Abstract
Isoflurane is a volatile inhaled anaesthetic widely used in animal research, with particular utility for hearing research. Isoflurane has been shown to blunt hearing sensitivity compared with the awake state, but little is known about how isoflurane compares with other anaesthetics with regard to hair cell transduction and auditory neurotransmission. The current study was undertaken in C57Bl/6J and C129/SvEv strains of mice to determine whether isoflurane anaesthesia affects hearing function relative to ketamine-based anaesthesia. Cochlear function and central auditory transmission were assessed using auditory brainstem response (ABR) and distortion product otoacoustic emission (DPOAE), comparing thresholds and input/output functions over time, for isoflurane vs. ketamine/xylazine/acepromazine anaesthesia. ABR thresholds at the most sensitive region of hearing (16 kHz) were initially higher under isoflurane anaesthesia. This reduced hearing sensitivity worsened over the 1 h study period, and also became evident with broadband click stimulus. Ketamine anaesthesia provided stable ABR thresholds. Although the growth functions were unchanged over time for both anaesthetics, the slopes under isoflurane anaesthesia were significantly less. Cubic (2f(1)-f(2)) DPOAE thresholds and growth functions were initially similar for both anaesthetics. After 60 min, DPOAE thresholds increased for both groups, but this effect was significantly greater with ketamine anaesthesia. The isoflurane-mediated increase in ABR thresholds over time is attributable to action on cochlear nerve activation, evident as a right-shift in the P1-N1 input/output function compared to K/X/A. The ketamine-based anaesthetic produced stable ABR thresholds and gain over time, despite a right-shift in the outer hair cell - mediated DPOAE input/output function.
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Affiliation(s)
- Jennie M E Cederholm
- Translational Neuroscience Facility, School of Medical Sciences, The University of New South Wales, UNSW Kensington Campus, Sydney, NSW Australia
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22
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Norman M, Tomscha K, Wehr M. Isoflurane blocks temporary tinnitus. Hear Res 2012; 290:64-71. [DOI: 10.1016/j.heares.2012.03.015] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2011] [Revised: 02/21/2012] [Accepted: 03/21/2012] [Indexed: 11/30/2022]
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Gonçalves R, McBrearty A, Pratola L, Calvo G, Anderson TJ, Penderis J. Clinical evaluation of cochlear hearing status in dogs using evoked otoacoustic emissions. J Small Anim Pract 2012; 53:344-51. [PMID: 22647213 DOI: 10.1111/j.1748-5827.2012.01229.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
OBJECTIVES Evoked otoacoustic emission testing is the preferred test in human patients for sensorineural deafness screening in neonates and cochlear outer hair cell function monitoring in adults. This study evaluated evoked otoacoustic emission testing for cochlear function assessment in dogs within a clinical setting. METHODS Two populations of anaesthetised dogs were included. In group 1 the evoked otoacoustic emission response was compared to the brainstem auditory evoked response in 10 dogs having hearing assessment. Group 2 comprised 43 presumed normal dogs, in which the suitability of two types of evoked otoacoustic emissions, transient-evoked and distortion product otoacoustic emissions, were evaluated (brainstem auditory evoked response was not performed in this group). RESULTS Valid transient-evoked otoacoustic emission and distortion-product otoacoustic emission responses were successfully recorded within the clinical setting and correctly identified deaf and hearing ears. Within presumed healthy dogs, normal otoacoustic emission response was demonstrated in more than 80% of dogs using a single, short distortion-product otoacoustic emission run and in 78% of dogs with valid transient-evoked otoacoustic emission responses using a series of three repeated transient-evoked otoacoustic emission short runs. CLINICAL SIGNIFICANCE Transient-evoked otoacoustic emission and distortion-product otoacoustic emission testing provided a rapid, non-invasive frequency-specific assessment of cochlear function. Transient-evoked otoacoustic emission and distortion product otoacoustic emission testing is suitable as a screening procedure to detect loss of cochlear function in dogs, although further investigation is needed.
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Affiliation(s)
- R Gonçalves
- School of Veterinary Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Bearsden Road, Glasgow
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Ruebhausen MR, Brozoski TJ, Bauer CA. A comparison of the effects of isoflurane and ketamine anesthesia on auditory brainstem response (ABR) thresholds in rats. Hear Res 2012; 287:25-9. [PMID: 22543090 DOI: 10.1016/j.heares.2012.04.005] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2011] [Revised: 03/29/2012] [Accepted: 04/04/2012] [Indexed: 11/18/2022]
Abstract
The auditory brainstem response (ABR) is an acoustically evoked potential commonly used to determine hearing sensitivity in laboratory animals. Both isoflurane and ketamine/xylazine anesthesia are commonly used to immobilize animals during ABR procedures. Hearing threshold determination is often the primary interest. Although a number of studies have examined the effect of different anesthetics on evoked potential waveforms and growth functions, none have directly compared their effect on ABR hearing threshold estimates. The present study used a within-subject comparison and typical threshold criteria, to examine the effect of isoflurane and ketamine/xylazine on ABR thresholds for clicks and pure-tone stimuli extending from 8 to 32 kHz. At comparable physiological doses, hearing thresholds obtained with isoflurane (1.7% in O(2)) were on average elevated across a broad frequency range by greater than 27 dB compared to ketamine/xylazine (ketamine HCl, 50mg/kg; xylazine, 9 mg/kg). This highly significant threshold effect (F(1,6) = 158.3403, p = 3.51 × 10(-22)) demonstrates a substantial difference between general anesthetics on auditory brainstem sensitivity. Potential mechanisms and implications for ABR threshold determination under anesthesia are discussed.
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Affiliation(s)
- M R Ruebhausen
- Southern Illinois University School of Medicine, Division of Otolaryngology Head and Neck Surgery, 801 N Rutledge, Rm 3205, Springfield, IL 62702, United States.
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McNerney KM, Burkard RF. The auditory steady state response: Far-field recordings from the chinchilla. Int J Audiol 2011; 51:200-9. [DOI: 10.3109/14992027.2011.631589] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Effects of electrical stimulation on the acoustically evoked auditory-nerve response in guinea pigs with a high-frequency hearing loss. Hear Res 2011; 272:95-107. [DOI: 10.1016/j.heares.2010.10.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2010] [Revised: 10/01/2010] [Accepted: 10/21/2010] [Indexed: 11/18/2022]
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Brittan-Powell EF, Christensen-Dalsgaard J, Tang Y, Carr C, Dooling RJ. The auditory brainstem response in two lizard species. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2010; 128:787-94. [PMID: 20707448 PMCID: PMC2933256 DOI: 10.1121/1.3458813] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2009] [Revised: 05/25/2010] [Accepted: 06/02/2010] [Indexed: 05/29/2023]
Abstract
Although lizards have highly sensitive ears, it is difficult to condition them to sound, making standard psychophysical assays of hearing sensitivity impractical. This paper describes non-invasive measurements of the auditory brainstem response (ABR) in both Tokay geckos (Gekko gecko; nocturnal animals, known for their loud vocalizations) and the green anole (Anolis carolinensis, diurnal, non-vocal animals). Hearing sensitivity was measured in 5 geckos and 7 anoles. The lizards were sedated with isoflurane, and ABRs were measured at levels of 1 and 3% isoflurane. The typical ABR waveform in response to click stimulation showed one prominent and several smaller peaks occurring within 10 ms of the stimulus onset. ABRs to brief tone bursts revealed that geckos and anoles were most sensitive between 1.6-2 kHz and had similar hearing sensitivity up to about 5 kHz (thresholds typically 20-50 dB SPL). Above 5 kHz, however, anoles were more than 20 dB more sensitive than geckos and showed a wider range of sensitivity (1-7 kHz). Generally, thresholds from ABR audiograms were comparable to those of small birds. Best hearing sensitivity, however, extended over a larger frequency range in lizards than in most bird species.
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Dichotomy of functional organization in the mouse auditory cortex. Nat Neurosci 2010; 13:361-8. [PMID: 20118924 PMCID: PMC2866453 DOI: 10.1038/nn.2490] [Citation(s) in RCA: 172] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2009] [Accepted: 12/29/2009] [Indexed: 12/27/2022]
Abstract
The sensory areas of the cerebral cortex possess multiple topographic representations of sensory dimensions. Gradient of frequency selectivity (tonotopy) is the dominant organizational feature in the primary auditory cortex, while other feature-based organizations are less well established. We probed the topographic organization of the mouse auditory cortex at the single cell level using in vivo two-photon Ca2+ imaging. Tonotopy was present on a large scale but was fractured on a fine scale. Intensity tuning, important in level-invariant representation, was observed in individual cells but was not topographically organized. The presence or near-absence of putative sub-threshold responses revealed a dichotomy in topographic organization. Inclusion of sub-threshold responses revealed a topographic clustering of neurons with similar response properties, while such clustering was absent in supra-threshold responses. This dichotomy indicates that groups of nearby neurons with locally shared inputs can perform independent parallel computations in ACX.
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