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Liu Y, Wu C, Chen T, Shen Q, Xiong Y, Chen Z, Li C. Evaluation of acoustic changes in and the healing outcomes of rat eardrums with pars tensa and pars flaccida perforations. Laryngoscope Investig Otolaryngol 2022; 7:816-824. [PMID: 35734049 PMCID: PMC9194967 DOI: 10.1002/lio2.797] [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: 01/06/2022] [Revised: 03/11/2022] [Accepted: 04/09/2022] [Indexed: 11/27/2022] Open
Abstract
Objectives To systematically explore the differences in acoustic changes and healing outcomes of tympanic membranes (TMs) with pars flaccida perforation (PFP) and pars tensa perforation (PTP). Methods We created PFPs and PTPs of various sizes in Sprague–Dawley rats, and evaluated TM umbo velocity and hearing function using laser Doppler vibrometry and auditory brainstem response (ABR) measurement before and immediately after perforation. Two weeks later, hearing was reevaluated and TMs were investigated by immunohistochemical staining. Results Small PFPs and PTPs did not significantly affect umbo velocity and hearing function. Large PFPs increased umbo velocity loss at low frequency (1.5 kHz) and elevated ABR thresholds within 1–2 kHz. Large PTP caused significant velocity loss at low frequencies from 1.5 to 3.5 kHz and threshold elevations at full frequencies (1–2 kHz). Two weeks after the perforation, the hearing function of rats with healed PFPs recovered completely. However, high‐frequency hearing loss (16–32 kHz) persisted in rats with healed PTPs. Morphological staining revealed that no increase in the thickness and obvious increase in collagen I level of regenerated par flaccida; regenerated pars tensa exhibited obvious increase in thickness and increased collagen I, while the collagen II regeneration was limited with discontinuous and disordered structure in regenerated pars tensa. Conclusion The hearing loss caused by large PFP limits at low frequencies while large PTP can lead to hearing loss at wide range frequencies. PFP and PTP have different functional outcomes after spontaneous healing, which is determined by the discrepant structure reconstruction and collagen regeneration.
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Affiliation(s)
- Yaoqian Liu
- Otolaryngology Research Institute Shanghai Jiao Tong University Affiliated Sixth People's Hospital Shanghai China
| | - Cuiping Wu
- Otolaryngology Research Institute Shanghai Jiao Tong University Affiliated Sixth People's Hospital Shanghai China
| | - Tingting Chen
- Department of Hearing and Language Rehabilitation Zhejiang Chinese Medicine University Hangzhou China
| | - Qiyue Shen
- Department of Hearing and Language Rehabilitation Shanghai University of Traditional Chinese Medicine Shanghai China
| | - Yuanping Xiong
- Department of Otolaryngology Head and Neck Surgery First Affiliated Hospital of Nanchang University Nanchang China
| | - Zhengnong Chen
- Otolaryngology Research Institute Shanghai Jiao Tong University Affiliated Sixth People's Hospital Shanghai China
- Department of Otolaryngology‐Head and Neck Surgery Shanghai Jiao Tong University Affiliated Sixth People's Hospital Shanghai China
| | - Chunyan Li
- Otolaryngology Research Institute Shanghai Jiao Tong University Affiliated Sixth People's Hospital Shanghai China
- Department of Otolaryngology‐Head and Neck Surgery Shanghai Jiao Tong University Affiliated Sixth People's Hospital Shanghai China
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Zhao H, Wang L, Chen L, Zhang J, Sun W, Salvi RJ, Huang YN, Wang M, Chen L. Temporary conductive hearing loss in early life impairs spatial memory of rats in adulthood. Brain Behav 2018; 8:e01004. [PMID: 29855161 PMCID: PMC6043706 DOI: 10.1002/brb3.1004] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 03/01/2018] [Accepted: 03/11/2018] [Indexed: 01/08/2023] Open
Abstract
INTRODUCTION It is known that an interruption of acoustic input in early life will result in abnormal development of the auditory system. Here, we further show that this negative impact actually spans beyond the auditory system to the hippocampus, a system critical for spatial memory. METHODS We induced a temporary conductive hearing loss (TCHL) in P14 rats by perforating the eardrum and allowing it to heal. The Morris water maze and Y-maze tests were deployed to evaluate spatial memory of the rats. Electrophysiological recordings and anatomical analysis were made to evaluate functional and structural changes in the hippocampus following TCHL. RESULTS The rats with the TCHL had nearly normal hearing at P42, but had a decreased performance with the Morris water maze and Y-maze tests compared with the control group. A functional deficit in the hippocampus of the rats with the TCHL was found as revealed by the depressed long-term potentiation and the reduced NMDA receptor-mediated postsynaptic current. A structural deficit in the hippocampus of those animals was also found as revealed the abnormal expression of the NMDA receptors, the decreased number of dendritic spines, the reduced postsynaptic density and the reduced level of neurogenesis. CONCLUSIONS Our study demonstrates that even temporary auditory sensory deprivation in early life of rats results in abnormal development of the hippocampus and consequently impairs spatial memory in adulthood.
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Affiliation(s)
- Han Zhao
- Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, China.,Auditory Research Laboratory, University of Science and Technology of China, Hefei, China
| | - Li Wang
- Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, China
| | - Liang Chen
- Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, China
| | - Jinsheng Zhang
- Department of Otolaryngology-Head and Neck Surgery, Wayne State University School of Medicine, Detroit, Michigan
| | - Wei Sun
- Center for Hearing and Deafness, State University of New York at Buffalo, Buffalo, New York
| | - Richard J Salvi
- Center for Hearing and Deafness, State University of New York at Buffalo, Buffalo, New York
| | - Yi-Na Huang
- Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, China.,Auditory Research Laboratory, University of Science and Technology of China, Hefei, China
| | - Ming Wang
- Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, China.,Auditory Research Laboratory, University of Science and Technology of China, Hefei, China
| | - Lin Chen
- Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, China.,Auditory Research Laboratory, University of Science and Technology of China, Hefei, China
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Sun W, Manohar S, Jayaram A, Kumaraguru A, Fu Q, Li J, Allman B. Early age conductive hearing loss causes audiogenic seizure and hyperacusis behavior. Hear Res 2011; 282:178-83. [PMID: 21872651 DOI: 10.1016/j.heares.2011.08.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2011] [Revised: 08/11/2011] [Accepted: 08/13/2011] [Indexed: 10/17/2022]
Abstract
Recent clinical reports found a high incidence of recurrent otitis media in children suffering hyperacusis, a marked intolerance to an otherwise ordinary environmental sound. However, it is unclear whether the conductive hearing loss caused by otitis media in early age will affect sound tolerance later in life. Thus, we have tested the effects of tympanic membrane (TM) damage at an early age on sound perception development in rats. Two weeks after the TM perforation, more than 80% of the rats showed audiogenic seizure (AGS) when exposed to loud sound (120 dB SPL white noise, < 1 min). The susceptibility of AGS lasted at least sixteen weeks after the TM damage, even the hearing loss recovered. The TM damaged rats also showed significantly enhanced acoustic startle responses compared to the rats without TM damage. These results suggest that early age conductive hearing loss may cause an impaired sound tolerance during development. In addition, the AGS can be suppressed by the treatment of vigabatrin, acute injections (250 mg/kg) or oral intakes (60 mg/kg/day for 7 days), an antiepileptic drug that inhibits the catabolism of GABA. c-Fos staining showed a strong staining in the inferior colliculus (IC) in the TM damaged rats, not in the control rats, after exposed to loud sound, indicating a hyper-excitability in the IC during AGS. These results indicate that early age conductive hearing loss can impair sound tolerance by reducing GABA inhibition in the IC, which may be related to hyperacusis seen in children with otitis media.
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Affiliation(s)
- Wei Sun
- Center for Hearing & Deafness, Department of Communicative Disorders and Sciences, The State University of New York at Buffalo, Buffalo, NY 14214, USA.
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Gratton MA, Bateman K, Cannuscio JF, Saunders JC. Outer- and middle-ear contributions to presbycusis in the Brown Norway rat. Audiol Neurootol 2007; 13:37-52. [PMID: 17715469 DOI: 10.1159/000107551] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2006] [Accepted: 05/30/2007] [Indexed: 11/19/2022] Open
Abstract
This paper examines the contribution of the outer and middle ears to the hearing loss associated with presbycusis in Brown Norway rats. Animals were formed into two groups; young adults (2-3 months old) and aged animals (approximately 34 months old). Auditory brainstem response (ABR) thresholds were obtained with the outer ear intact or surgically removed. Tympanic membrane (TM) velocity transfer functions were measured from the umbo with the outer ear removed. The length of the auditory meatus, TM surface area, and TM thickness were quantified. The ABR thresholds were 17-26 dB less sensitive in the aged animals between 8.0 and 40.0 kHz when the outer ear was intact. A significant and reliable reduction in the aged rat velocity transfer function of 5-8 dB occurred between 10.0 and 32.0 kHz, while the low frequency velocity response was only a few decibels greater in the younger animals. The ABR threshold differences between young adult and aged ears were compensated by removing the outer/middle ear effects of aging to reveal a purely sensorineural component of presbycusis. The outer and middle ear effects were calculated directly when the ABR and TM velocity data were obtained with the outer ear removed. The outer ear intact condition was modeled in order to compare the ABR data obtained with the outer ear intact with the TM velocity data obtained with the outer removed. With either procedure, removal of the age-related contributions of the outer and middle ear to the ABR threshold resulted in similar age-related ABR threshold shifts between the two age groups. The pure sensorineural threshold shift component of the ABR response was restricted to frequencies between 5.0 and 20.0 kHz and reached a maximum of approximately 15 dB. These results support the conclusion that there is an outer- and middle-ear contribution to the threshold loss defining presbycusis.
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MESH Headings
- Acoustic Stimulation
- Aging/pathology
- Animals
- Ear Canal/pathology
- Ear Canal/physiopathology
- Ear Ossicles/pathology
- Ear Ossicles/physiopathology
- Ear, External/pathology
- Ear, External/physiopathology
- Evoked Potentials, Auditory, Brain Stem
- Hearing Loss, Conductive/pathology
- Hearing Loss, Conductive/physiopathology
- Hearing Loss, Sensorineural/pathology
- Hearing Loss, Sensorineural/physiopathology
- Male
- Models, Biological
- Presbycusis/pathology
- Presbycusis/physiopathology
- Rats
- Rats, Inbred BN
- Tympanic Membrane/pathology
- Tympanic Membrane/physiopathology
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Affiliation(s)
- Michael Anne Gratton
- Department of Otorhinolaryngology, Head and Neck Surgery, University of Pennsylvania, Philadelphia, PA, USA.
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Akache F, Funnell WRJ, Daniel SJ. An experimental study of tympanic membrane and manubrium vibrations in rats. Audiol Neurootol 2006; 12:49-58. [PMID: 17119333 DOI: 10.1159/000097247] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2006] [Accepted: 08/09/2006] [Indexed: 12/17/2022] Open
Abstract
Rats are potentially very useful for auditory research because the middle ear structures are easily approachable and because rats are relatively inexpensive. The goal of the present study was to better characterize the mechanics of the rat middle ear by measuring frequency responses at multiple points on the tympanic membrane and manubrium. A laser Doppler vibrometer was used to measure the vibrations. Measurements were made on 7 rats. Tympanic membrane vibrations are presented for 7 different points in the frequency range of 1-10 kHz. The repeatability of the measurements and the interanimal variability at the umbo are also presented. The vibration modes of the tympanic membrane and manubrium were investigated.
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Affiliation(s)
- F Akache
- McGill Auditory Sciences Laboratory, McGill University, Montréal, Canada
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