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Gross J, Knipper M, Mazurek B. Candidate Key Proteins in Tinnitus: A Bioinformatic Study of Synaptic Transmission in Spiral Ganglion Neurons. Cell Mol Neurobiol 2023; 43:4189-4207. [PMID: 37736859 PMCID: PMC10661836 DOI: 10.1007/s10571-023-01405-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2023] [Accepted: 08/24/2023] [Indexed: 09/23/2023]
Abstract
To study key proteins associated with changes in synaptic transmission in the spiral ganglion in tinnitus, we build three gene lists from the GeneCard database: 1. Perception of sound (PoS), 2. Acoustic stimulation (AcouStim), and 3. Tinnitus (Tin). Enrichment analysis by the DAVID database resulted in similar Gene Ontology (GO) terms for cellular components in all gene lists, reflecting synaptic structures known to be involved in auditory processing. The STRING protein-protein interaction (PPI) network and the Cytoscape data analyzer were used to identify the top two high-degree proteins (HDPs) and their high-score interaction proteins (HSIPs) identified by the combined score (CS) of the corresponding edges. The top two protein pairs (key proteins) for the PoS are BDNF-GDNF and OTOF-CACNA1D and for the AcouStim process BDNF-NTRK2 and TH-CALB1. The Tin process showed BDNF and NGF as HDPs, with high-score interactions with NTRK1 and NGFR at a comparable level. Compared to the PoS and AcouStim process, the number of HSIPs of key proteins (CS > 90. percentile) increases strongly in Tin. In the PoS and AcouStim networks, BDNF receptor signaling is the dominant pathway, and in the Tin network, the NGF-signaling pathway is of similar importance. Key proteins and their HSIPs are good indicators of biological processes and of signaling pathways characteristic for the normal hearing on the one hand and tinnitus on the other.
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Affiliation(s)
- Johann Gross
- Tinnitus Center, Charité-Universitätsmedizin Berlin, Berlin, Germany.
- Leibniz Society of Science Berlin, Berlin, Germany.
| | - Marlies Knipper
- Department of Otolaryngology, Head and Neck Surgery, Tübingen Hearing Research Center (THRC), Molecular Physiology of Hearing, University of Tübingen, Tübingen, Germany
- Leibniz Society of Science Berlin, Berlin, Germany
| | - Birgit Mazurek
- Tinnitus Center, Charité-Universitätsmedizin Berlin, Berlin, Germany
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Elliott KL, Fritzsch B, Yamoah EN, Zine A. Age-Related Hearing Loss: Sensory and Neural Etiology and Their Interdependence. Front Aging Neurosci 2022; 14:814528. [PMID: 35250542 PMCID: PMC8891613 DOI: 10.3389/fnagi.2022.814528] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2021] [Accepted: 01/03/2022] [Indexed: 12/19/2022] Open
Abstract
Age-related hearing loss (ARHL) is a common, increasing problem for older adults, affecting about 1 billion people by 2050. We aim to correlate the different reductions of hearing from cochlear hair cells (HCs), spiral ganglion neurons (SGNs), cochlear nuclei (CN), and superior olivary complex (SOC) with the analysis of various reasons for each one on the sensory deficit profiles. Outer HCs show a progressive loss in a basal-to-apical gradient, and inner HCs show a loss in a apex-to-base progression that results in ARHL at high frequencies after 70 years of age. In early neonates, SGNs innervation of cochlear HCs is maintained. Loss of SGNs results in a considerable decrease (~50% or more) of cochlear nuclei in neonates, though the loss is milder in older mice and humans. The dorsal cochlear nuclei (fusiform neurons) project directly to the inferior colliculi while most anterior cochlear nuclei reach the SOC. Reducing the number of neurons in the medial nucleus of the trapezoid body (MNTB) affects the interactions with the lateral superior olive to fine-tune ipsi- and contralateral projections that may remain normal in mice, possibly humans. The inferior colliculi receive direct cochlear fibers and second-order fibers from the superior olivary complex. Loss of the second-order fibers leads to hearing loss in mice and humans. Although ARHL may arise from many complex causes, HC degeneration remains the more significant problem of hearing restoration that would replace the cochlear implant. The review presents recent findings of older humans and mice with hearing loss.
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Affiliation(s)
- Karen L. Elliott
- Department of Biology, University of Iowa, Iowa City, IA, United States
| | - Bernd Fritzsch
- Department of Biology, University of Iowa, Iowa City, IA, United States
- *Correspondence: Bernd Fritzsch
| | - Ebenezer N. Yamoah
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada, Reno, NV, United States
| | - Azel Zine
- LBN, Laboratory of Bioengineering and Nanoscience, University of Montpellier, Montpellier, France
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Gray DT, Barnes CA. Experiments in macaque monkeys provide critical insights into age-associated changes in cognitive and sensory function. Proc Natl Acad Sci U S A 2019:201902279. [PMID: 31871147 DOI: 10.1073/pnas.1902279116] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
The use of animal models in brain aging research has led to numerous fundamental insights into the neurobiological processes that underlie changes in brain function associated with normative aging. Macaque monkeys have become the predominant nonhuman primate model system in brain aging research due to their striking similarities to humans in their behavioral capacities, sensory processing abilities, and brain architecture. Recent public concern about nonhuman primate research has made it imperative to attempt to clearly articulate the potential benefits to human health that this model enables. The present review will highlight how nonhuman primates provide a critical bridge between experiments conducted in rodents and development of therapeutics for humans. Several studies discussed here exemplify how nonhuman primate research has enriched our understanding of cognitive and sensory decline in the aging brain, as well as how this work has been important for translating mechanistic implications derived from experiments conducted in rodents to human brain aging research.
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Fischer N, Johnson Chacko L, Majerus A, Potrusil T, Riechelmann H, Schmutzhard J, Schrott-Fischer A, Glueckert R. Age-Dependent Calcium-Binding Protein Expression in the Spiral Ganglion and Hearing Performance of C57BL/6J and 129/SvJ Mice. ORL J Otorhinolaryngol Relat Spec 2019; 81:138-154. [PMID: 31170714 DOI: 10.1159/000499472] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 03/08/2019] [Indexed: 11/19/2022]
Abstract
BACKGROUND/AIMS Calcium-binding proteins in neurons buffer intracellular free Ca2+ ions, which interact with proteins controlling enzymatic and ion channel activity. The heterogeneous distribution of calretinin, calbindin, and parvalbumin influences calcium homeostasis, and calcium-related neuronal processes play an important role in neuronal aging and degeneration. This study evaluated age-related changes in calretinin, calbindin, and parvalbumin immune reactivity in spiral ganglion cells. METHODS A total of 16 C57BL/6J and 16 129/SvJ mice at different ages (2, 4, 7, and 12 months) were included in the study. Hearing thresholds were assessed using auditory brainstem response before inner ears were excised for further evaluation. Semiquantitative immunohistochemistry for the aforementioned calcium-binding proteins was performed at the cellular level. RESULTS The hearing thresholds of C57BL/6J and 129/SvJ mice increased significantly by 7 months of age. The average immune reactivity of calbin-din as well as the relative number of positive cells increased significantly with aging, but no significant alterations in calretinin or parvalbumin were observed. CONCLUSIONS Upregulation of calbindin could serve as a protection to compensate for functional deficits that occur with aging. Expression of both calretinin and parvalbumin seem to be stabilizing factors in murine inner ears up to the age of 12 months in C57BL/6J and 129/SvJ mice.
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Affiliation(s)
- Natalie Fischer
- Department of Otorhinolaryngology, Medical University Innsbruck, Innsbruck, Austria
| | - Lejo Johnson Chacko
- Department of Otorhinolaryngology, Medical University Innsbruck, Innsbruck, Austria
| | - Alexandra Majerus
- Department of Otorhinolaryngology, Medical University Innsbruck, Innsbruck, Austria
| | - Thomas Potrusil
- Department of Otorhinolaryngology, Medical University Innsbruck, Innsbruck, Austria
| | - Herbert Riechelmann
- Department of Otorhinolaryngology, Medical University Innsbruck, Innsbruck, Austria
| | - Joachim Schmutzhard
- Department of Otorhinolaryngology, Medical University Innsbruck, Innsbruck, Austria
| | | | - Rudolf Glueckert
- Department of Otorhinolaryngology, Medical University Innsbruck, Innsbruck, Austria.,Department of Otorhinolaryngology, Tirol Kliniken, University Clinics of Innsbruck, Innsbruck, Austria
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Huang Q, Ou Y, Xiong H, Yang H, Zhang Z, Chen S, Ye Y, Zheng Y. The miR-34a/Bcl-2 Pathway Contributes to Auditory Cortex Neuron Apoptosis in Age-Related Hearing Loss. Audiol Neurootol 2017; 22:96-103. [DOI: 10.1159/000454874] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Accepted: 11/30/2016] [Indexed: 11/19/2022] Open
Abstract
Hypothesis: The miR-34a/Bcl-2 signaling pathway may play a role in the mechanisms related to age-related hearing loss (AHL) in the auditory cortex. Background: The auditory cortex plays a key role in the recognition and processing of complex sound. It is difficult to explain why patients with AHL have poor speech recognition, so increasing numbers of studies have focused on its central change. Although micro (mi)RNAs in the central nervous system have recently been increasingly reported to be associated with age-related diseases, the molecular mechanisms of AHL in the auditory cortex are not fully understood. Methods: The auditory brainstem response was used to assess the hearing ability of C57BL/6 mice, and q-PCR, immunohistochemistry, and Western blotting were used to detect the expression levels of miR-34a and Bcl-2 in the mouse auditory cortex. TUNEL and DNA fragmentation were adopted to detect the apoptosis of neurons in the auditory cortex. To verify the relationship of miR-34a and Bcl-2, we transfected an miR-34a mimic or miR-34a inhibitor into primary auditory cortex neurons. Results: In this study, miR-34a/Bcl-2 signaling was examined in auditory cortex neurons during aging. miR-34a and apoptosis increased in the auditory cortex neurons of C57BL/6 mice with aging, whereas an age-related decrease in Bcl-2 was determined. In the primary neurons of the auditory cortex, miR-34a overexpression inhibited Bcl-2, leading to an increase in apoptosis. Moreover, miR-34a knockdown increased Bcl-2 expression and diminished apoptosis. Conclusion: Our results support a link between age-related apoptosis in auditory cortex neurons and miR-34a/Bcl-2 signaling, which may serve as a potential mechanism of the expression of AHL in the auditory cortex.
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Godfrey DA, Chen K, O'Toole TR, Mustapha AI. Amino acid and acetylcholine chemistry in the central auditory system of young, middle-aged and old rats. Hear Res 2017; 350:173-188. [DOI: 10.1016/j.heares.2017.05.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Revised: 04/24/2017] [Accepted: 05/03/2017] [Indexed: 02/04/2023]
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Ouda L, Profant O, Syka J. Age-related changes in the central auditory system. Cell Tissue Res 2015; 361:337-58. [DOI: 10.1007/s00441-014-2107-2] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Accepted: 12/22/2014] [Indexed: 12/19/2022]
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Gray DT, Engle JR, Rudolph ML, Recanzone GH. Regional and age-related differences in GAD67 expression of parvalbumin- and calbindin-expressing neurons in the rhesus macaque auditory midbrain and brainstem. J Comp Neurol 2014; 522:4074-84. [PMID: 25091320 PMCID: PMC4263274 DOI: 10.1002/cne.23659] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2014] [Revised: 07/31/2014] [Accepted: 08/01/2014] [Indexed: 11/08/2022]
Abstract
Neurons expressing the calcium binding proteins (CaBPs) parvalbumin (PV) and calbindin (CB) have shown age-related density changes throughout the ascending auditory system of both rodents and macaque monkeys. In the cerebral cortex, neurons expressing these CaBPs express markers of γ-aminobutyric acidergic neurotransmission, such as GAD67, and have well-understood physiological response properties. Recent evidence suggests that, in the rodent auditory brainstem, CaBP-containing cells do not express GAD67. It is unknown whether PV- and CB-containing cells in subcortical auditory structures of macaques similarly do not express GAD67, and a better understanding of the neurotransmission of neurons expressing these proteins is necessary for understanding the age-related changes in their density throughout the macaque auditory system. This was investigated with immunofluorescent double-labeling techniques to coregister PV- and CB-expressing neurons with GAD67 in the superior olivary complex and the inferior colliculus of young and aged rhesus macaques. The proportions of GAD67-expressing PV- and CB-positive neurons were computed with unbiased sampling techniques. Our results indicate that between 42% and 62% of PV- and CB-positive neurons in the auditory brainstem and midbrain express GAD67, which is significantly less than in the cerebrum. In general, fewer PV(+) neurons and more CB(+) neurons expressed GAD67 as a function of age. These results demonstrate that the inhibitory molecular profile of PV- and CB-expressing neurons can change with age in subcortical auditory structures and that these neurons are distinct from the well-described inhibitory interneurons that express these proteins in the cerebral cortex.
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Affiliation(s)
- D T Gray
- Center for Neuroscience, University of California at Davis, Davis, California, 95616; Evelyn F. McKnight Brain Institute, University of Arizona, Tucson, Arizona, 85721
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Gray DT, Engle JR, Recanzone GH. Age-related neurochemical changes in the rhesus macaque cochlear nucleus. J Comp Neurol 2014; 522:1527-41. [PMID: 24127432 DOI: 10.1002/cne.23479] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Revised: 08/28/2013] [Accepted: 09/25/2013] [Indexed: 11/07/2022]
Abstract
Neurochemical changes in the expression of various proteins within the central auditory system have been associated with natural aging. These changes may compensate in part for the loss of auditory sensitivity arising from two phenomena of the aging auditory system: cochlear histopathologies and increased excitability of central auditory neurons. Recent studies in the macaque monkey have revealed age-related changes in the density of nicotinamide adenine dinucleotide phosphate (NADPH)-diaphorase (NADPHd) and parvalbumin (PV)-positive cells within the inferior colliculus and superior olivary complex. The cochlear nucleus (CN), which is the first central auditory nucleus, remains unstudied. Since the CN participates in the generation of the auditory brainstem response (ABR) and receives direct innervation from the cochlea, it serves as an ideal nucleus to compare the relationship between these neurochemical changes and the physiological and peripheral changes of the aging auditory system. We used stereological sampling to calculate the densities of NADPHd and PV reactive neurons within the three subdivisions of the CN in middle-aged and aged rhesus macaques. Regression analyses of these values with ABR properties and cochlear histopathologies revealed relationships between these cell types and the changing characteristics of the aging auditory system. Our results indicate that NADPHd expression does change with age in a specific subdivision of the CN, but PV does not. Conversely, PV expression correlated with ABR amplitudes and outer hair cell loss in the cochlea, but NADPHd did not. These results indicate that NADPHd and PV may take part in distinct compensatory efforts of the aging auditory system.
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Affiliation(s)
- Daniel T Gray
- Center for Neuroscience, University of California at Davis, Davis, CA, 95616
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Gröschel M, Hubert N, Müller S, Ernst A, Basta D. Age-dependent changes of calcium related activity in the central auditory pathway. Exp Gerontol 2014; 58:235-43. [DOI: 10.1016/j.exger.2014.08.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Revised: 07/31/2014] [Accepted: 08/28/2014] [Indexed: 10/24/2022]
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Bloom S, Williams A, MacLeod KM. Heterogeneous calretinin expression in the avian cochlear nucleus angularis. J Assoc Res Otolaryngol 2014; 15:603-20. [PMID: 24752525 DOI: 10.1007/s10162-014-0453-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Accepted: 03/21/2014] [Indexed: 10/25/2022] Open
Abstract
Multiple calcium-binding proteins (CaBPs) are expressed at high levels and in complementary patterns in the auditory pathways of birds, mammals, and other vertebrates, but whether specific members of the CaBP family can be used to identify neuronal subpopulations is unclear. We used double immunofluorescence labeling of calretinin (CR) in combination with neuronal markers to investigate the distribution of CR-expressing neurons in brainstem sections of the cochlear nucleus in the chicken (Gallus gallus domesticus). While CR was homogeneously expressed in cochlear nucleus magnocellularis, CR expression was highly heterogeneous in cochlear nucleus angularis (NA), a nucleus with diverse cell types analogous in function to neurons in the mammalian ventral cochlear nucleus. To quantify the distribution of CR in the total NA cell population, we used antibodies against neuronal nuclear protein (NeuN), a postmitotic neuron-specific nuclear marker. In NA neurons, NeuN label was variably localized to the cell nucleus and the cytoplasm, and the intensity of NeuN immunoreactivity was inversely correlated with the intensity of CR immunoreactivity. The percentage of CR + neurons in NA increased from 31 % in embryonic (E)17/18 chicks, to 44 % around hatching (E21), to 51 % in postnatal day (P) 8 chicks. By P8, the distribution of CR + neurons was uniform, both rostrocaudal and in the tonotopic (dorsoventral) axis. Immunoreactivity for the voltage-gated potassium ion channel Kv1.1, used as a marker for physiological type, showed broad and heterogeneous postsynaptic expression in NA, but did not correlate with CR expression. These results suggest that CR may define a subpopulation of neurons within nucleus angularis.
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Engle JR, Gray DT, Turner H, Udell JB, Recanzone GH. Age-related neurochemical changes in the rhesus macaque inferior colliculus. Front Aging Neurosci 2014; 6:73. [PMID: 24795627 PMCID: PMC4001037 DOI: 10.3389/fnagi.2014.00073] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Accepted: 03/31/2014] [Indexed: 01/19/2023] Open
Abstract
Age-related hearing loss (ARHL) is marked by audiometric hearing deficits that propagate along the auditory pathway. Neurochemical changes as a function of aging have also been identified in neurons along the auditory pathway in both rodents and carnivores, however, very little is known about how these neurochemicals change in the non-human primate. To examine how these compensatory neurochemical changes relate to normal aging and audiometric sensitivity along the auditory pathway, we collected auditory brainstem responses (ABRs) and brain specimens from seven rhesus monkeys spanning in age from 15 to 35 years old, and examined the relationship between click evoked ABR thresholds and the ABR evoked pure tone average (PTA) and changes in the number of parvalbumin and NADPH-diaphorase positive cells in the auditory midbrain. We found that the number of parvalbumin positive cells in the central nucleus and the surrounding cortex regions of the inferior colliculus were strongly correlated with advancing age and ABR PTA. We also found that the numbers of NADPHd positive cells in these same regions were not associated with normal aging or changes in the ABR thresholds. These findings suggest that the auditory midbrain undergoes an up-regulation of parvalbumin expressing neurons with aging that is related to changes in the processing of frequencies across the audiometric range.
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Affiliation(s)
- James R Engle
- Evelyn F. McKnight Brain Institute, University of Arizona at Tucson Tucson, AZ, USA ; Center for Neuroscience, University of California at Davis Davis, CA, USA ; Department of Psychology, University of California at Davis Davis, CA, USA
| | - Daniel T Gray
- Center for Neuroscience, University of California at Davis Davis, CA, USA
| | - Heather Turner
- Center for Neuroscience, University of California at Davis Davis, CA, USA
| | - Julia B Udell
- Center for Neuroscience, University of California at Davis Davis, CA, USA
| | - Gregg H Recanzone
- Center for Neuroscience, University of California at Davis Davis, CA, USA ; Department of Psychology, University of California at Davis Davis, CA, USA ; Department of Neurobiology, Physiology and Behavior, University of California at Davis Davis, CA USA
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Gray DT, Rudolph ML, Engle JR, Recanzone GH. Parvalbumin increases in the medial and lateral geniculate nuclei of aged rhesus macaques. Front Aging Neurosci 2013; 5:69. [PMID: 24265617 PMCID: PMC3821177 DOI: 10.3389/fnagi.2013.00069] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2013] [Accepted: 10/16/2013] [Indexed: 12/20/2022] Open
Abstract
Subcortical auditory structures in the macaque auditory system increase their densities of neurons expressing the calcium binding protein parvalbumin (PV) with age. However, it is unknown whether these increases occur in the thalamic division of the auditory system, the medial geniculate nucleus (MGN). Furthermore, it is also unclear whether these age-related changes are specific to the macaque auditory system or are generalized to other sensory systems. To address these questions, the PV immunoreactivity of the medial and lateral geniculate nuclei (LGN) from seven rhesus macaques ranging in age from 15 to 35 was assessed. Densities of PV expressing neurons in the three subdivisions of the MGN and the six layers of the LGN were calculated separately using unbiased stereological sampling techniques. We found that the ventral and magnocellular subdivisions of the MGN and all six layers of the LGN increased their expressions of PV with age, although increases in the MGN were greater in magnitude than in the LGN. Together, these results suggest that the MGN shows age-related increases in PV expression as is seen throughout the macaque ascending auditory system, and that the analogous region of the visual system shows smaller increases. We conclude that, while there are some similarities between sensory systems, the age-related neurochemical changes seen throughout the macaque auditory system cannot be fully generalized to other sensory systems.
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Affiliation(s)
- Daniel T. Gray
- Center for Neuroscience, University of California at DavisDavis, CA, USA
| | - Megan L. Rudolph
- Center for Neuroscience, University of California at DavisDavis, CA, USA
| | - James R. Engle
- Evelyn F. McKnight Brain Institute, University of ArizonaTucson, AZ, USA
| | - Gregg H. Recanzone
- Center for Neuroscience, University of California at DavisDavis, CA, USA
- Department of Neurobiology, Physiology and Behavior, University of California at DavisDavis, CA, USA
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Nemeth A, Szabadfi K, Fulop B, Reglodi D, Kiss P, Farkas J, Szalontai B, Gabriel R, Hashimoto H, Tamas A. Examination of calcium-binding protein expression in the inner ear of wild-type, heterozygous and homozygous pituitary adenylate cyclase-activating polypeptide (PACAP)-knockout mice in kanamycin-induced ototoxicity. Neurotox Res 2013; 25:57-67. [PMID: 24155155 DOI: 10.1007/s12640-013-9428-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Revised: 09/23/2013] [Accepted: 09/24/2013] [Indexed: 11/24/2022]
Abstract
Pituitary adenylate cyclase-activating polypeptide (PACAP) is a neuropeptide with diverse biological effects. It also occurs and exerts protective effects in sensory organs; however, little is known about its effects in the auditory system. Recently, we have shown that PACAP protects cochlear cells against oxidative-stress-induced apoptosis and homozygous PACAP-deficient animals show stronger expression of Ca(2+)-binding proteins in the hair cells of the inner ear, but there are no data about the consequences of the lack of endogenous PACAP in different ototoxic insults such as aminoglycoside-induced toxicity. In this study, we examined the effect of kanamycin treatment on Ca(2+)-binding protein expression in hair cells of wild-type, heterozygous and homozygous PACAP-deficient mice. We treated 5-day-old mice with kanamycin, and 2 days later, we examined the Ca(2+)-binding protein expression of the hair cells with immunohistochemistry. We found stronger expression of Ca(2+)-binding proteins in the hair cells of control heterozygous and homozygous PACAP-deficient mice compared with wild-type animals. Kanamycin induced a significant increase in Ca(2+)-binding protein expression in wild-type and heterozygous PACAP-deficient mice, but the baseline higher expression in homozygous PACAP-deficient mice did not show further changes after the treatment. Elevated endolymphatic Ca(2+) is deleterious for the cochlear function, against which the high concentration of Ca(2+)-buffers in hair cells may protect. Meanwhile, the increased immunoreactivity of Ca(2+)-binding proteins in the absence of PACAP provide further evidence for the important protective role of PACAP in ototoxicity, but further investigations are necessary to examine the exact role of endogenous PACAP in ototoxic insults.
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Affiliation(s)
- A Nemeth
- Department of Oto-rhino-laryngology, University of Pecs, Pecs, Hungary
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Lee KY. Pathophysiology of age-related hearing loss (peripheral and central). Korean J Audiol 2013; 17:45-9. [PMID: 24653905 PMCID: PMC3936539 DOI: 10.7874/kja.2013.17.2.45] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Revised: 08/02/2013] [Accepted: 08/07/2013] [Indexed: 11/22/2022]
Abstract
Age-related hearing loss (presbycusis) refers to bilaterally symmetrical hearing loss resulting from aging process. Presbycusis is a complex phenomenon characterized by audiometric threshold shift, deterioration in speech-understanding and speech-perception difficulties in noisy environments. Factors contributing to presbycusis include mitochondria DNA mutation, genetic disorders including Ahl, hypertension, diabetes, metabolic disease and other systemic diseases in the intrinsic aspects. Extrinsic factors include noise, ototoxic medication and diet. However, presbycusis may not be related to the intrinsic and extrinsic factors separately. Presbycusis affects not only the physical, cognitive and emotional activities of patients, but also their social functioning. As a result, patients' quality of life deteriorates, compounded by various symptoms including depression, social isolation and lower self-esteem. Presbycusis is classified into six categories, as based on results of audiometric tests and temporal bone pathology, established by Schuknecht (1993): sensory, neural, metabolic or strial, cochlear conductive, mixed and indeterminate types. Among these, metabolic presbycusis is the mainstay of presbycusis types. Age-related changes also develop in the central hearing system. Functional decline of the central auditory system, caused by aging, reduces speech-understanding in noisy background and increase temporal processing deficits in gap-detection measures. This study reviews the literature on the age-related hearing loss.
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Affiliation(s)
- Kyu-Yup Lee
- Department of Otorhinolaryngology-Head and Neck Surgery, School of Medicine, Kyungpook National University, Daegu, Korea
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16
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Affiliation(s)
- Qingwei Ruan
- Central Lab; Shanghai Institute of Geriatrics and Gerontology; Huadong Hospital, Shanghai Medical College, Fudan University; Shanghai China
| | - Cheng Ma
- Central Lab; Shanghai Institute of Geriatrics and Gerontology; Huadong Hospital, Shanghai Medical College, Fudan University; Shanghai China
| | - Ruxin Zhang
- Central Lab; Shanghai Institute of Geriatrics and Gerontology; Huadong Hospital, Shanghai Medical College, Fudan University; Shanghai China
| | - Zhuowei Yu
- Central Lab; Shanghai Institute of Geriatrics and Gerontology; Huadong Hospital, Shanghai Medical College, Fudan University; Shanghai China
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Ouda L, Burianova J, Syka J. Age-related changes in calbindin and calretinin immunoreactivity in the central auditory system of the rat. Exp Gerontol 2012; 47:497-506. [DOI: 10.1016/j.exger.2012.04.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2012] [Revised: 03/22/2012] [Accepted: 04/10/2012] [Indexed: 11/22/2022]
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Sekiya T, Viberg A, Kojima K, Sakamoto T, Nakagawa T, Ito J, Canlon B. Trauma-specific insults to the cochlear nucleus in the rat. J Neurosci Res 2012; 90:1924-31. [PMID: 22715005 DOI: 10.1002/jnr.23093] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2011] [Revised: 03/27/2012] [Accepted: 05/07/2012] [Indexed: 12/19/2022]
Abstract
The effect of acoustic overstimulation on the neuronal number of the cochlear nucleus (CN) was investigated by using unbiased stereological methods in rats. We found that, after 9 weeks of recovery, neurons in the anteroventral cochlear nucleus (AVCN) degenerated, whereas those in the posteroventral and dorsal cochlear nuclei (PVCN and DCN) were preserved. The noise trauma induced near complete loss of the outer hair cells throughout the cochlea, and the inner hair cells were preserved only in the more apical regions. This pattern of selective loss of AVCN neurons in this study was different from trauma induced by auditory deafferentation by mechanical compression of auditory neurons. In contrast to noise trauma, mechanical compression caused loss of neurons in the PVCN and DCN. After 5 weeks of recovery from mechanical compression, there was no loss of inner or outer hair cells. These findings indicate that auditory deprivation, induced by different experimental manipulations, can have strikingly different consequences for the central auditory system. We hypothesized that AVCN neuronal death was induced by excitotoxic mechanisms via AMPA-type glutamate receptors and that excitatory neuronal circuits developed after acoustic overstimulation protected the PVCN and DCN against neuronal death. The results of the present study demonstrate that hearing loss from different etiologies will cause different patterns of neuronal degeneration in the CN. These findings are important for enhancing the performance of cochlear implants and auditory brainstem implants, because diverse types of hearing loss can selectively affect neuronal degeneration of the CN.
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Affiliation(s)
- Tetsuji Sekiya
- Department of Otolaryngology, Head and Neck Surgery, Kyoto University Graduate School of Medicine, Kyoto, Japan.
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Tamas A, Szabadfi K, Nemeth A, Fulop B, Kiss P, Atlasz T, Gabriel R, Hashimoto H, Baba A, Shintani N, Helyes Z, Reglodi D. Comparative Examination of Inner Ear in Wild Type and Pituitary Adenylate Cyclase Activating Polypeptide (PACAP)-Deficient Mice. Neurotox Res 2011; 21:435-44. [DOI: 10.1007/s12640-011-9298-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2011] [Revised: 11/17/2011] [Accepted: 12/06/2011] [Indexed: 12/30/2022]
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Fyk-Kolodziej B, Shimano T, Gong TW, Holt AG. Vesicular glutamate transporters: spatio-temporal plasticity following hearing loss. Neuroscience 2011; 178:218-39. [PMID: 21211553 DOI: 10.1016/j.neuroscience.2010.12.059] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2010] [Revised: 12/27/2010] [Accepted: 12/28/2010] [Indexed: 12/22/2022]
Abstract
An immunocytochemical comparison of vGluT1 and vGluT3 in the cochlear nucleus (CN) of deafened versus normal hearing rats showed the first example of vGluT3 immunostaining in the dorsal and ventral CN and revealed temporal and spatial changes in vGluT1 localization in the CN after cochlear injury. In normal hearing rats vGluT1 immunostaining was restricted to terminals on CN neurons while vGluT3 immunolabeled the somata of the neurons. This changed in the ventral cochlear nucleus (VCN) 3 days following deafness, where vGluT1 immunostaining was no longer seen in large auditory nerve terminals but was instead found in somata of VCN neurons. In the dorsal cochlear nucleus (DCN), while vGluT1 labeling of terminals decreased, there was no labeling of neuronal somata. Therefore, loss of peripheral excitatory input results in co-localization of vGluT1 and vGluT3 in VCN neuronal somata. Postsynaptic glutamatergic neurons can use retrograde signaling to control their presynaptic inputs and these results suggest vGluTs could play a role in regulating retrograde signaling in the CN under different conditions of excitatory input. Changes in vGluT gene expression in CN neurons were found 3 weeks following deafness using qRT-PCR with significant increases in vGluT1 gene expression in both ventral and dorsal CN while vGluT3 gene expression decreased in VCN but increased in DCN.
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Affiliation(s)
- B Fyk-Kolodziej
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, MI 48201, USA
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Willott JF, Vandenbosche J, Shimizu T. Effects of a high-frequency augmented acoustic environment on parvalbumin immunolabeling in the anteroventral cochlear nucleus of DBA/2J and C57BL/6J mice. Hear Res 2010; 261:36-41. [PMID: 20060461 DOI: 10.1016/j.heares.2009.12.029] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2009] [Revised: 12/30/2009] [Accepted: 12/31/2009] [Indexed: 11/22/2022]
Abstract
Neurons in the anteroventral cochlear nucleus (AVCN) of DBA/2J (D2) and C57BL/6J (B6) mice were immunohistochemically labeled for the calcium binding protein parvalbumin (PV). Prior to this, mice were treated for 12h nightly with a "high-frequency" augmented acoustic environment (HAAE: repetitive bursts of a 70 dB sound pressure level, half-octave noise band centered at 20 kHz). This was done during the period that hearing loss occurs: pre-weaning to 55 days in D2 mice and weaning to 9 months in B6 mice. After HAAE treatment in D2 mice, high-frequency hearing loss was ameliorated and fewer PV-labeled neurons were found in the AVCN compared to untreated controls. HAAE treatment in B6 mice exacerbated high-frequency hearing loss, yet the number of PV-labeled AVCN neurons in treated mice did not differ significantly from that of control mice. The findings suggest that HAAE treatment provides relief from physiological stress caused by deprivation of auditory input from the impaired cochlea.
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Hong SM, Chung SY, Park MS, Huh YB, Park MS, Yeo SG. Immunoreactivity of calcium-binding proteins in the central auditory nervous system of aged rats. J Korean Neurosurg Soc 2009; 45:231-5. [PMID: 19444349 DOI: 10.3340/jkns.2009.45.4.231] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2009] [Accepted: 04/05/2009] [Indexed: 11/27/2022] Open
Abstract
OBJECTIVE While many factors contribute to aging, changes in calcium homeostasis and calcium related neuronal processes are likely to be important. High intracellular calcium is toxic to cells and alterations in calcium homeostasis are associated with changes in calcium-binding proteins, which confine free Ca(2+). We therefore assayed the expression of the calcium binding proteins calretinin and calbindin in the central auditory nervous system of rats. METHODS Using antibodies to calretinin and calbindin, we assayed their expression in the cochlear nucleus, superior olivary nucleus, inferior colliculus, medial geniculate body and auditory cortex of young (4 months old) and aged (24 months old) rats. RESULTS Calretinin and calbindin staining intensity in neurons of the cochlear nucleus was significantly higher in aged than in young rats (p<0.05) The number and staining intensity of calretinin-positive neurons in the inferior colliculus, and of calbindin-positive neurons in the superior olivary nucleus were greater in aged than in young rats (p<0.05). CONCLUSION These results suggest that auditory processing is altered during aging, which may be due to increased intracellular Ca(2+) concentration, consequently leading to increased immunoreactivity toward calcium-binding proteins.
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Affiliation(s)
- Seok Min Hong
- Department of Otorhinolaryngology and Head and Neck Surgery, College of Medicine, KyungHee University, Seoul, Korea
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Sekiya T, Canlon B, Viberg A, Matsumoto M, Kojima K, Ono K, Yoshida A, Kikkawa YS, Nakagawa T, Ito J. Selective vulnerability of adult cochlear nucleus neurons to de-afferentation by mechanical compression. Exp Neurol 2009; 218:117-23. [PMID: 19393647 DOI: 10.1016/j.expneurol.2009.04.014] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2009] [Accepted: 04/15/2009] [Indexed: 12/22/2022]
Abstract
It is well established that the cochlear nucleus (CN) of developing species is susceptible to loss of synaptic connections from the auditory periphery. Less information is known about how de-afferentation affects the adult auditory system. We investigated the effects of de-afferentation to the adult CN by mechanical compression. This experimental model is quantifiable and highly reproducible. Five weeks after mechanical compression to the axons of the auditory neurons, the total number of neurons in the CN was evaluated using un-biased stereological methods. A region-specific degeneration of neurons in the dorsal cochlear nucleus (DCN) and posteroventral cochlear nucleus (PVCN) by 50% was found. Degeneration of neurons in the anteroventral cochlear nucleus (AVCN) was not found. An imbalance between excitatory and inhibitory synaptic transmission after de-afferentation may have played a crucial role in the development of neuronal cell demise in the CN. The occurrence of a region-specific loss of adult CN neurons illustrates the importance of evaluating all regions of the CN to investigate the effects of de-afferentation. Thus, this experimental model may be promising to obtain not only the basic knowledge on auditory nerve/CN degeneration but also the information relevant to the application of cochlear or auditory brainstem implants.
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Affiliation(s)
- Tetsuji Sekiya
- Department of Otolaryngology, Head and Neck Surgery, Kyoto University Graduate School of Medicine, Sakyou-ku, Kyoto 606-8507, Japan.
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