scholarly journals Acoustic Trauma Changes the Parvalbumin-Positive Neurons in Rat Auditory Cortex

2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
Congli Liu ◽  
Tao Xu ◽  
Xiaopeng Liu ◽  
Yina Huang ◽  
Haitao Wang ◽  
...  
Keyword(s):  
Auditory Cortex ◽  
Noise Exposure ◽  
Stable State ◽  
Auditory Brainstem ◽  
Acoustic Trauma ◽  
Cortical Inhibition ◽  
Response Threshold ◽  
Compensatory Mechanism ◽  
Central System ◽  
Brainstem Response

Acoustic trauma is being reported to damage the auditory periphery and central system, and the compromised cortical inhibition is involved in auditory disorders, such as hyperacusis and tinnitus. Parvalbumin-containing neurons (PV neurons), a subset of GABAergic neurons, greatly shape and synchronize neural network activities. However, the change of PV neurons following acoustic trauma remains to be elucidated. The present study investigated how auditory cortical PV neurons change following unilateral 1 hour noise exposure (left ear, one octave band noise centered at 16 kHz, 116 dB SPL). Noise exposure elevated the auditory brainstem response threshold of the exposed ear when examined 7 days later. More detectable PV neurons were observed in both sides of the auditory cortex of noise-exposed rats when compared to control. The detectable PV neurons of the left auditory cortex (ipsilateral to the exposed ear) to noise exposure outnumbered those of the right auditory cortex (contralateral to the exposed ear). Quantification of Western blotted bands revealed higher expression level of PV protein in the left cortex. These findings of more active PV neurons in noise-exposed rats suggested that a compensatory mechanism might be initiated to maintain a stable state of the brain.

scholarly journals Differences in Calcium Clearance at Inner Hair Cell Active Zones May Underlie the Difference in Susceptibility to Noise-Induced Cochlea Synaptopathy of C57BL/6J and CBA/CaJ Mice

2021 ◽  
Vol 8 ◽  
Author(s):  
Hongchao Liu ◽  
Hu Peng ◽  
Longhao Wang ◽  
Pengcheng Xu ◽  
Zhaoyan Wang ◽  
...  
Keyword(s):  
Hair Cell ◽  
Clearance Rate ◽  
Noise Exposure ◽  
Auditory Brainstem ◽  
Response Threshold ◽  
Inner Hair Cell ◽  
Cba Mice ◽  
Calcium Clearance ◽  
Brainstem Response ◽  
Susceptibility To Noise

Noise exposure of a short period at a moderate level can produce permanent cochlear synaptopathy without seeing lasting changes in audiometric threshold. However, due to the species differences in inner hair cell (IHC) calcium current that we have recently discovered, the susceptibility to noise exposure may vary, thereby impact outcomes of noise exposure. In this study, we investigate the consequences of noise exposure in the two commonly used animal models in hearing research, CBA/CaJ (CBA) and C57BL/6J (B6) mice, focusing on the functional changes of cochlear IHCs. In the CBA mice, moderate noise exposure resulted in a typical fully recovered audiometric threshold but a reduced wave I amplitude of auditory brainstem responses. In contrast, both auditory brainstem response threshold and wave I amplitude fully recovered in B6 mice at 2 weeks after noise exposure. Confocal microscopy observations found that ribbon synapses of IHCs recovered in B6 mice but not in CBA mice. To further characterize the molecular mechanism underlying these different phenotypes in synaptopathy, we compared the ratio of Bax/Bcl-2 with the expression of cytochrome-C and found increased activity in CBA mice after noise exposure. Under whole-cell patch clamped IHCs, we acquired two-photon calcium imaging around the active zone to evaluate the Ca2+ clearance rate and found that CBA mice have a slower calcium clearance rate. Our results indicated that excessive accumulation of calcium due to acoustic overexposure and slow clearance around the presynaptic ribbon might lead to disruption of calcium homeostasis, followed by mitochondrial dysfunction of IHCs that cause susceptibility of noise-induced cochlear synaptopathy in CBA mice.

Protective effects of brain-derived neurotrophic factor on the noise-damaged cochlear spiral ganglion

2010 ◽  
Vol 125 (5) ◽  
pp. 449-454 ◽  
Author(s):  
S-Q Zhai ◽  
W Guo ◽  
Y-Y Hu ◽  
N Yu ◽  
Q Chen ◽  
...  
Keyword(s):  
Neurotrophic Factor ◽  
Auditory Brainstem Response ◽  
Noise Exposure ◽  
Recombinant Adenovirus ◽  
Spiral Ganglion ◽  
Brain Derived Neurotrophic Factor ◽  
Auditory Brainstem ◽  
Response Threshold ◽  
Protective Effects ◽  
Brainstem Response

AbstractObjective:To explore the protective effects of brain-derived neurotrophic factor on the noise-damaged cochlear spiral ganglion.Methods:Recombinant adenovirus brain-derived neurotrophic factor vector, recombinant adenovirus LacZ and artificial perilymph were prepared. Guinea pigs with audiometric auditory brainstem response thresholds of more than 75 dB SPL, measured seven days after four hours of noise exposure at 135 dB SPL, were divided into three groups. Adenovirus brain-derived neurotrophic factor vector, adenovirus LacZ and perilymph were infused into the cochleae of the three groups, variously. Eight weeks later, the cochleae were stained immunohistochemically and the spiral ganglion cells counted.Results:The auditory brainstem response threshold recorded before and seven days after noise exposure did not differ significantly between the three groups. However, eight weeks after cochlear perfusion, the group receiving brain-derived neurotrophic factor had a significantly decreased auditory brainstem response threshold and increased spiral ganglion cell count, compared with the adenovirus LacZ and perilymph groups.Conclusion:When administered via cochlear infusion following noise damage, brain-derived neurotrophic factor appears to improve the auditory threshold, and to have a protective effect on the spiral ganglion cells.

Methionine Sulfoxide Reductase A Knockout Mice Show Progressive Hearing Loss and Sensitivity to Acoustic Trauma

2018 ◽  
Vol 23 (1) ◽  
pp. 20-31 ◽  
Author(s):  
Safa Alqudah ◽  
Mark Chertoff ◽  
Dianne Durham ◽  
Jackob Moskovitz ◽  
Hinrich Staecker ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Knockout Mice ◽  
Noise Exposure ◽  
Methionine Sulfoxide ◽  
Auditory Brainstem ◽  
Acoustic Trauma ◽  
Methionine Sulfoxide Reductase ◽  
Distortion Product Otoacoustic Emission ◽  
Distortion Product ◽  
Brainstem Response

Methionine sulfoxide reductases (MsrA and MsrB) protect the biological activity of proteins from oxidative modifications to methionine residues and are important for protecting against the pathological effects of neurodegenerative diseases. In the current study, we characterized the auditory phenotype of the MsrA knockout mouse. Young MsrA knockout mice showed small high-frequency threshold elevations for auditory brainstem response and distortion product otoacoustic emission compared to those of wild-type mice, which progressively worsened in older MsrA knockout mice. MsrA knockout mice showed an increased sensitivity to noise at young and older ages, suggesting that MsrA is part of a mechanism that protects the cochlea from acoustic damage. MsrA mRNA in the cochlea was increased following acoustic stimulation. Finally, expression of mRNA MsrB1 was compromised at 6 months old, but not in younger MsrA knockout mice (compared to controls). The identification of MsrA in the cochlea as a protective mediator from both early onset hearing loss and acoustic trauma expands our understanding of the pathways that may induce protection from acoustic trauma and foster further studies on how to prevent the damaging effect of noise exposure through Msr-based therapy.

scholarly journals NADPH Oxidase 2-Mediated Insult in the Auditory Cortex of Zucker Diabetic Fatty Rats

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Zheng-De Du ◽  
Wei Wei ◽  
Shukui Yu ◽  
Qing-Ling Song ◽  
Ke Liu ◽  
...  
Keyword(s):  
Oxidative Damage ◽  
Nadph Oxidase ◽  
Auditory Cortex ◽  
Auditory System ◽  
Auditory Brainstem ◽  
Secondary Symptom ◽  
Zucker Diabetic Fatty Rats ◽  
Brainstem Response ◽  
Zdf Rats ◽  
Nadph Oxidase 2

Clinical data has confirmed that auditory impairment may be a secondary symptom of type 2 diabetes mellitus (T2DM). However, mechanisms underlying pathologic changes that occur in the auditory system, especially in the central auditory system (CAS), remain poorly understood. In this study, Zucker diabetic fatty (ZDF) rats were used as a T2DM rat model to observe ultrastructural alterations in the auditory cortex and investigate possible mechanisms underlying CAS damage in T2DM. The auditory brainstem response (ABR) of ZDF rats was found to be markedly elevated in low (8 kHz) and high (32 kHz) frequencies. Protein expression of NADPH oxidase 2 (NOX2) and its matching subunits P22phox, P47phox, and P67phox was increased in the auditory cortex of ZDF rats. Expression of 8-hydroxy-2-deoxyguanosine (8-OHdG), a marker of DNA oxidative damage, was also increased in the neuronal mitochondria of the auditory cortex of ZDF rats. Additionally, decreases in the mitochondrial total antioxidant capabilities (T-AOC), adenosine triphosphate (ATP) production, and mitochondrial membrane potential (MMP) were detected in the auditory cortex of ZDF rats, suggesting mitochondrial dysfunction. Transmission electron microscopy results indicated that ultrastructural damage had occurred to neurovascular units and mitochondria in the auditory cortex of ZDF rats. Furthermore, cytochrome c (Cyt c) translocation from mitochondria to cytoplasm and caspase 3-dependent apoptosis were also detected in the auditory cortex of ZDF rats. Consequently, the study demonstrated that T2DM may cause morphological damage to the CAS and that NOX2-associated mitochondrial oxidative damage and apoptosis may be partly responsible for this insult.

scholarly journals The human auditory brainstem response to running speech reveals a subcortical mechanism for selective attention

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Antonio Elia Forte ◽  
Octave Etard ◽  
Tobias Reichenbach
Keyword(s):  
Mathematical Method ◽  
Selective Attention ◽  
Auditory Cortex ◽  
Auditory Brainstem Response ◽  
Background Noise ◽  
Ecological Validity ◽  
Acoustic Stimulus ◽  
Auditory Brainstem ◽  
Brainstem Response ◽  
Target Speaker

Humans excel at selectively listening to a target speaker in background noise such as competing voices. While the encoding of speech in the auditory cortex is modulated by selective attention, it remains debated whether such modulation occurs already in subcortical auditory structures. Investigating the contribution of the human brainstem to attention has, in particular, been hindered by the tiny amplitude of the brainstem response. Its measurement normally requires a large number of repetitions of the same short sound stimuli, which may lead to a loss of attention and to neural adaptation. Here we develop a mathematical method to measure the auditory brainstem response to running speech, an acoustic stimulus that does not repeat and that has a high ecological validity. We employ this method to assess the brainstem's activity when a subject listens to one of two competing speakers, and show that the brainstem response is consistently modulated by attention.

Effects of noise exposure on neonatal auditory brainstem response thresholds in pregnant guinea pigs at different gestational periods

2016 ◽  
Vol 43 (1) ◽  
pp. 78-86
Author(s):  
Chihiro Morimoto ◽  
Kazuhiko Nario ◽  
Tadashi Nishimura ◽  
Ryota Shimokura ◽  
Hiroshi Hosoi ◽  
...  
Keyword(s):  
Auditory Brainstem Response ◽  
Guinea Pigs ◽  
Noise Exposure ◽  
Auditory Brainstem ◽  
Brainstem Response ◽  
Response Thresholds

Low-Frequency Auditory Brainstem Response Threshold

1988 ◽  
Vol 17 (3) ◽  
pp. 171-178 ◽  
Author(s):  
E. Laukli ◽  
O. Fjermedal ◽  
I. W. S. Mair
Keyword(s):  
Auditory Brainstem Response ◽  
Low Frequency ◽  
Auditory Brainstem ◽  
Response Threshold ◽  
Brainstem Response

scholarly journals Auditory Brainstem Response Altered in Humans With Noise Exposure Despite Normal Outer Hair Cell Function

2017 ◽  
Vol 38 (1) ◽  
pp. e1-e12 ◽  
Author(s):  
Naomi F. Bramhall ◽  
Dawn Konrad-Martin ◽  
Garnett P. McMillan ◽  
Susan E. Griest
Keyword(s):  
Hair Cell ◽  
Auditory Brainstem Response ◽  
Noise Exposure ◽  
Outer Hair Cell ◽  
Cell Function ◽  
Auditory Brainstem ◽  
Brainstem Response
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