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Duan B, Peng KA, Wang L. Injury and protection of spiral ganglion neurons. Chin Med J (Engl) 2024; 137:651-656. [PMID: 37407223 PMCID: PMC10950135 DOI: 10.1097/cm9.0000000000002765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2022] [Indexed: 07/07/2023] Open
Abstract
ABSTRACT Cochlear spiral ganglion neurons (SGNs) are bipolar ganglion cells and are the first neurons in the auditory transduction pathway. They transmit complex acoustic information from hair cells to second-order sensory neurons in the cochlear nucleus for sound processing. Injury to SGNs causes largely irreversible hearing impairment because these neurons are highly differentiated cells and cannot regenerate, making treatment of sensorineural hearing loss (SNHL) arising from SGN injury difficult. When exposed to ototoxic drugs or damaging levels of noise or when there is loss of neurotrophic factors (NTFs), aging, and presence of other factors, SGNs can be irreversibly damaged, resulting in SNHL. It has been found that NTFs and stem cells can induce regeneration among dead spiral ganglion cells. In this paper, we summarized the present knowledge regarding injury, protection, and regeneration of SGNs.
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Affiliation(s)
- Beilei Duan
- Department of Otorhinolaryngology, Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, China
| | - Kevin A. Peng
- Department of Neurotology, House Clinic, Los Angeles, CA 90017, USA
| | - Line Wang
- Department of Otorhinolaryngology, Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, China
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2
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Guo R, Zhang S, Yu S, Li X, Liu X, Shen Y, Wei J, Wu Y. Inclusion of frailty improved performance of delirium prediction for elderly patients in the cardiac intensive care unit (D-FRAIL): A prospective derivation and external validation study. Int J Nurs Stud 2023; 147:104582. [PMID: 37672971 DOI: 10.1016/j.ijnurstu.2023.104582] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 07/29/2023] [Accepted: 07/30/2023] [Indexed: 09/08/2023]
Abstract
BACKGROUND The elderly patients admitted to cardiac intensive care unit (CICU) are at relatively high risk for developing delirium. A simple and reliable predictive model can benefit them from early recognition of delirium followed by timely and appropriate preventive strategies. OBJECTIVE To explore the role of frailty in delirium prediction and develop and validate a delirium predictive model including frailty for elderly patients in CICU. DESIGN A prospective, observational cohort study. SETTINGS CICU at China-Japan Friendship Hospital from March 1, 2022 to August 25, 2022 (derivation cohort); CICU at Beijing Anzhen Hospital affiliated to Capital Medical University from March 14, 2023 to May 8, 2023 (external validation cohort). PARTICIPANTS A total of 236 and 90 participants were enrolled in the derivation and external validation cohorts, respectively. Participants in the derivation cohort were assigned into either the delirium (n = 70) or non-delirium group (n = 166) based on the occurrence of delirium. METHODS The simplified Chinese version of the Confusion Assessment Method for the Diagnosis of Delirium in the Intensive Care Unit was used to assess delirium twice a day at 8:00-10:00 and 18:00-20:00 until the onset of delirium or discharge from the CICU. Frailty was assessed using the FRAIL scale during the first 24 h in the CICU. Other possible risk factors were collected prospectively through patient interviews and medical records review. After processing missing data via multiple imputations, univariate analysis and bootstrapped forward stepwise logistic regression were performed to select optimal predictors and develop the models. The models were internally validated using bootstrapping and evaluated comprehensively via discrimination, calibration, and clinical utility in both the derivation and external validation cohorts. RESULTS The study developed D-FRAIL predictive model using FRAIL score, hearing impairment, Acute Physiology and Chronic Health Evaluation-II score, and fibrinogen. The area under the receiver operating characteristic curve (AUC) was 0.937 (95% confidence interval [CI]: 0.907-0.967) and 0.889 (95%CI: 0.840-0.938) even after bootstrapping in the derivation cohort. Inclusion of frailty was demonstrated to improve the model performance greatly with the AUC increased from 0.851 to 0.937 (p < 0.001). In the external validation cohort, the AUC of D-FRAIL model was 0.866 (95%CI: 0.782-0.907). Calibration plots and decision curve analysis suggested good calibration and clinical utility of the D-FRAIL model in both the derivation and external validation cohorts. CONCLUSIONS For elderly patients in the CICU, FRAIL score is an independent delirium predictor and the D-FRAIL model demonstrates superior performance in predicting delirium.
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Affiliation(s)
- Rongrong Guo
- School of Nursing, Capital Medical University, Beijing 100069, China
| | - Shan Zhang
- School of Nursing, Capital Medical University, Beijing 100069, China
| | - Saiying Yu
- School of Nursing, Capital Medical University, Beijing 100069, China
| | - Xiangyu Li
- School of Nursing, Capital Medical University, Beijing 100069, China
| | - Xinju Liu
- Cardiac Intensive Care Unit, China-Japan Friendship Hospital, Beijing 100029, China
| | - Yanling Shen
- Surgical Intensive Care Unit, China-Japan Friendship Hospital, Beijing 100029, China
| | - Jinling Wei
- Cardiac Intensive Care Unit, Beijing Anzhen Hospital Affiliated to Capital Medical University, Beijing 100029, China
| | - Ying Wu
- School of Nursing, Capital Medical University, Beijing 100069, China.
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Graham AS, Ben-Azu B, Tremblay MÈ, Torre P, Senekal M, Laughton B, van der Kouwe A, Jankiewicz M, Kaba M, Holmes MJ. A review of the auditory-gut-brain axis. Front Neurosci 2023; 17:1183694. [PMID: 37600010 PMCID: PMC10435389 DOI: 10.3389/fnins.2023.1183694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 07/17/2023] [Indexed: 08/22/2023] Open
Abstract
Hearing loss places a substantial burden on medical resources across the world and impacts quality of life for those affected. Further, it can occur peripherally and/or centrally. With many possible causes of hearing loss, there is scope for investigating the underlying mechanisms involved. Various signaling pathways connecting gut microbes and the brain (the gut-brain axis) have been identified and well established in a variety of diseases and disorders. However, the role of these pathways in providing links to other parts of the body has not been explored in much depth. Therefore, the aim of this review is to explore potential underlying mechanisms that connect the auditory system to the gut-brain axis. Using select keywords in PubMed, and additional hand-searching in google scholar, relevant studies were identified. In this review we summarize the key players in the auditory-gut-brain axis under four subheadings: anatomical, extracellular, immune and dietary. Firstly, we identify important anatomical structures in the auditory-gut-brain axis, particularly highlighting a direct connection provided by the vagus nerve. Leading on from this we discuss several extracellular signaling pathways which might connect the ear, gut and brain. A link is established between inflammatory responses in the ear and gut microbiome-altering interventions, highlighting a contribution of the immune system. Finally, we discuss the contribution of diet to the auditory-gut-brain axis. Based on the reviewed literature, we propose numerous possible key players connecting the auditory system to the gut-brain axis. In the future, a more thorough investigation of these key players in animal models and human research may provide insight and assist in developing effective interventions for treating hearing loss.
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Affiliation(s)
- Amy S. Graham
- Imaging Sciences, Neuroscience Institute, University of Cape Town, Cape Town, South Africa
- Department of Human Biology, Division of Biomedical Engineering, University of Cape Town, Cape Town, South Africa
| | - Benneth Ben-Azu
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
- Department of Pharmacology, Faculty of Basic Medical Sciences, College of Health Sciences, Delta State University, Abraka, Delta State, Nigeria
| | - Marie-Ève Tremblay
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
- Département de Médecine Moléculaire, Université Laval, Québec City, QC, Canada
- Axe Neurosciences, Centre de Recherche du CHU de Québec, Université Laval, Quebec City, QC, Canada
- Neurology and Neurosurgery Department, McGill University, Montreal, QC, Canada
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada
- Centre for Advanced Materials and Related Technology (CAMTEC), University of Victoria, Victoria, BC, Canada
- Institute for Aging and Lifelong Health, University of Victoria, Victoria, BC, Canada
| | - Peter Torre
- School of Speech, Language, and Hearing Sciences, San Diego State University, San Diego, CA, United States
| | - Marjanne Senekal
- Department of Human Biology, Division of Physiological Sciences, University of Cape Town, Cape Town, South Africa
| | - Barbara Laughton
- Family Clinical Research Unit, Department of Pediatrics and Child Health, Stellenbosch University, Cape Town, South Africa
| | - Andre van der Kouwe
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Boston, MA, United States
- Department of Radiology, Harvard Medical School, Boston, MA, United States
| | - Marcin Jankiewicz
- Imaging Sciences, Neuroscience Institute, University of Cape Town, Cape Town, South Africa
- Department of Human Biology, Division of Biomedical Engineering, University of Cape Town, Cape Town, South Africa
| | - Mamadou Kaba
- Department of Pathology, Division of Medical Microbiology, University of Cape Town, Cape Town, South Africa
| | - Martha J. Holmes
- Imaging Sciences, Neuroscience Institute, University of Cape Town, Cape Town, South Africa
- Department of Human Biology, Division of Biomedical Engineering, University of Cape Town, Cape Town, South Africa
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
- ImageTech, Simon Fraser University, Surrey, BC, Canada
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4
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Parezanović M, Ilić N, Ostojić S, Stevanović G, Ječmenica J, Maver A, Sarajlija A. Sensorineural Hearing Loss in a Child with Succinic Semialdehyde Dehydrogenase Deficiency. Balkan J Med Genet 2023; 26:63-68. [PMID: 37576789 PMCID: PMC10413887 DOI: 10.2478/bjmg-2023-0008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/15/2023] Open
Abstract
Succinic semialdehyde dehydrogenase (SSADH) deficiency is a rare autosomal-recessive disorder of gamma-aminobutyric acid (GABA) metabolism, resulting in accumulation of GABA and gamma-hydroxybutyric acid (GHB) in physiological fluids. Approximately 450 patients have been diagnosed worldwide with this inherited neurotransmitter disorder. We report on a five-year-old male patient, homozygous for the pathogenic variant (NM_170740:c.1265G>A) in ALDH5A1 presenting with an unexpected association of typical SSADH deficiency manifestations with bilateral sensorineural hearing loss (SNHL). Brainstem evoked response audiometry (BERA) testing showed mid-frequency sensorineural hearing damage that suggested a hereditary component to SNHL. Whole exome sequencing (WES) failed to discern other genetic causes of deafness. Several variants of uncertain significance (VUS) detected in genes known for their role in hearing physiology could not be verified as the cause for the SNHL. It is known that central auditory processing depends on a delicate balance between excitatory and inhibitory neurotransmission, and GABA is known to play a significant role in this process. Additionally, excessive concentrations of accumulated GABA and GBH are known to cause a down-regulation of GABA receptors, which could have an adverse influence on hearing function. However, these mechanisms are very speculative in context of SNHL in a patient with inherited disorder of GABA metabolism. Injury of the globi pallidi, one of hallmarks of SSADH deficiency, could also be a contributory factor to SNHL, as was suspected in some other inborn errors in metabolism. We hope that this case will contribute to the understanding of phenotypic complexity of SSADH deficiency.
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Affiliation(s)
- M Parezanović
- Department of Pediatric Intensive Care, Mother and Child Health Care Institute “Dr Vukan Čupić”, Belgrade, Serbia
| | - N Ilić
- Clinical Genetics Outpatient Clinic, Mother and Child Health Care Institute “Dr Vukan Čupić”, Belgrade, Serbia
| | - S Ostojić
- Department of Neurology, Mother and Child Health Care Institute “Dr Vukan Čupić”, Belgrade, Serbia
- University of Belgrade, Faculty of Medicine
| | - G Stevanović
- Clinic of Neurology and Psychiatry for Children and Youth, University of Belgrade, Faculty of Medicine, Belgrade, Serbia
| | - J Ječmenica
- Department of Otorhinolaryngology, Mother and Child Health Care Institute “Dr Vukan Čupić”, Belgrade, Serbia
| | - A Maver
- Clinical Institute of Genomic Medicine, University Medical Centre Ljubljana, Ljubljana, Slovenia
| | - A Sarajlija
- Clinical Genetics Outpatient Clinic, Mother and Child Health Care Institute “Dr Vukan Čupić”, Belgrade, Serbia
- University of Belgrade, Faculty of Medicine
- University of Eastern Sarajevo, Faculty of Medicine, Foča, Republic of Srpska, Bosnia and Hercegovina
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5
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Xue B, Meng X, Kao JPY, Kanold PO. Age-related changes in excitatory and inhibitory intra-cortical circuits in auditory cortex of C57Bl/6 mice. Hear Res 2023; 429:108685. [PMID: 36701895 PMCID: PMC9928889 DOI: 10.1016/j.heares.2022.108685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2022] [Revised: 12/16/2022] [Accepted: 12/26/2022] [Indexed: 12/28/2022]
Abstract
A common impairment in aging is age-related hearing loss (presbycusis), which manifests as impaired spectrotemporal processing. Aging is accompanied by alteration in normal inhibitory (GABA) neurotransmission, and changes in excitatory (NMDA and AMPA) synapses in the auditory cortex (ACtx). However, the circuits affected by these synaptic changes remain unknown. Mice of the C57Bl/6J strain show premature age-related hearing loss and changes in functional responses in ACtx. We thus investigated how auditory cortical microcircuits change with age by comparing young (∼ 6 weeks) and aged (>1 year old) C57Bl/6J mice. We performed laser scanning photostimulation (LSPS) combined with whole-cell patch clamp recordings from Layer (L) 2/3 cells in primary auditory cortex (A1) of young adult and aged C57Bl/6J mice. We found that L2/3 cells in aged C57Bl/6J mice display functional hypoconnectivity of both excitatory and inhibitory circuits. Compared to cells from young C57Bl/6 mice, cells from aged C57Bl/6J mice have fewer excitatory connections with weaker connection strength. Whereas young adult and aged C57Bl/6J mice have similar amounts of inhibitory connections, the strength of local inhibition is weaker in the aged group. We confirmed these results by recording miniature excitatory (mEPSCs) and inhibitory synaptic currents (mIPSCs). Our results suggest a specific reduction in excitatory and inhibitory intralaminar cortical circuits in aged C57Bl/6J mice compared with young adult animals. We speculate that these unbalanced changes in cortical circuits contribute to the functional manifestations of age-related hearing loss.
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Affiliation(s)
- Binghan Xue
- Department of Biology, University of Maryland, College Park, MD 20742, United States
| | - Xiangying Meng
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21205, United States; Department of Biology, University of Maryland, College Park, MD 20742, United States
| | - Joseph P Y Kao
- Center for Biomedical Engineering and Technology, and Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201, United States
| | - Patrick O Kanold
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21205, United States; Department of Biology, University of Maryland, College Park, MD 20742, United States.
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6
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Wang C, Qiu J, Li G, Wang J, Liu D, Chen L, Song X, Cui L, Sun Y. Application and prospect of quasi-targeted metabolomics in age-related hearing loss. Hear Res 2022; 424:108604. [PMID: 36116178 DOI: 10.1016/j.heares.2022.108604] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2022] [Revised: 08/28/2022] [Accepted: 09/03/2022] [Indexed: 11/04/2022]
Abstract
Age-related hearing loss (ARHL) is a common sensory deficit in the elderly, which seriously affects physical and mental health. Therefore, understanding its underlying molecular mechanisms and taking interventions to treat ARHL are urgently needed. In our study, cochlea of 4-week-old C57BL/6 mice as the Youth group (n = 6) and 48-week-old cochlea as the Old group (n = 6) were subjected to quasi-targeted metabolomics analysis by Ultra high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). In total, 208 differential metabolites were identified in 12 cochlea samples, which highlighted the following discriminant compounds: tryptophan, piperidine, methionine, L-arginine, histamine, serotonin, acetylcholine, and 4-aminobutyric acid. Differentially expressed metabolites were identified which were involved in KEGG pathways related to the digestion and absorption of oxidative stress associated amino acids, Synaptic vesicle cycle of serotonin, Pantothenate and CoA Biosynthesis. These findings are a first step toward elucidating the pathophysiological pathways involved in the etiology of ARHL and provide the possibility to further explore the mechanisms of ARHL using metabolomic analysis.
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Affiliation(s)
- Chen Wang
- School of Clinical Medicine, Weifang Medical University, Baotong West Street 7166, Weifang, China; Department of Otorhinolaryngology, Head and Neck Surgery, Yantai Yuhuangding Hospital, Qingdao University, 20 East Yuhuangding Road, Yantai, Shandong 264000, China; Shandong Provincial Clinical Research Center for Otorhinolaryngologic Diseases, 20 East Yuhuangding Road, Yantai, Shandong 264000, China
| | - Jingjing Qiu
- Department of Otorhinolaryngology, Head and Neck Surgery, Yantai Yuhuangding Hospital, Qingdao University, 20 East Yuhuangding Road, Yantai, Shandong 264000, China; Shandong Provincial Clinical Research Center for Otorhinolaryngologic Diseases, 20 East Yuhuangding Road, Yantai, Shandong 264000, China
| | - Guangjin Li
- School of Clinical Medicine, Weifang Medical University, Baotong West Street 7166, Weifang, China; Department of Otorhinolaryngology, Head and Neck Surgery, Yantai Yuhuangding Hospital, Qingdao University, 20 East Yuhuangding Road, Yantai, Shandong 264000, China; Shandong Provincial Clinical Research Center for Otorhinolaryngologic Diseases, 20 East Yuhuangding Road, Yantai, Shandong 264000, China
| | - Junxin Wang
- School of Clinical Medicine, Weifang Medical University, Baotong West Street 7166, Weifang, China; Department of Otorhinolaryngology, Head and Neck Surgery, Yantai Yuhuangding Hospital, Qingdao University, 20 East Yuhuangding Road, Yantai, Shandong 264000, China; Shandong Provincial Clinical Research Center for Otorhinolaryngologic Diseases, 20 East Yuhuangding Road, Yantai, Shandong 264000, China
| | - Dawei Liu
- Department of Otorhinolaryngology, Head and Neck Surgery, Yantai Yuhuangding Hospital, Qingdao University, 20 East Yuhuangding Road, Yantai, Shandong 264000, China; Shandong Provincial Clinical Research Center for Otorhinolaryngologic Diseases, 20 East Yuhuangding Road, Yantai, Shandong 264000, China
| | - Liang Chen
- Department of Otorhinolaryngology, Head and Neck Surgery, Yantai Yuhuangding Hospital, Qingdao University, 20 East Yuhuangding Road, Yantai, Shandong 264000, China; Shandong Provincial Clinical Research Center for Otorhinolaryngologic Diseases, 20 East Yuhuangding Road, Yantai, Shandong 264000, China
| | - Xicheng Song
- Department of Otorhinolaryngology, Head and Neck Surgery, Yantai Yuhuangding Hospital, Qingdao University, 20 East Yuhuangding Road, Yantai, Shandong 264000, China; Shandong Provincial Clinical Research Center for Otorhinolaryngologic Diseases, 20 East Yuhuangding Road, Yantai, Shandong 264000, China
| | - Limei Cui
- Department of Otorhinolaryngology, Head and Neck Surgery, Yantai Yuhuangding Hospital, Qingdao University, 20 East Yuhuangding Road, Yantai, Shandong 264000, China; Shandong Provincial Clinical Research Center for Otorhinolaryngologic Diseases, 20 East Yuhuangding Road, Yantai, Shandong 264000, China.
| | - Yan Sun
- Department of Otorhinolaryngology, Head and Neck Surgery, Yantai Yuhuangding Hospital, Qingdao University, 20 East Yuhuangding Road, Yantai, Shandong 264000, China; Shandong Provincial Clinical Research Center for Otorhinolaryngologic Diseases, 20 East Yuhuangding Road, Yantai, Shandong 264000, China.
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7
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A BK channel-targeted peptide induces age-dependent improvement in behavioral and neural sound representation. Neurobiol Aging 2021; 110:61-72. [PMID: 34861480 DOI: 10.1016/j.neurobiolaging.2021.10.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 10/22/2021] [Accepted: 10/25/2021] [Indexed: 11/23/2022]
Abstract
Recent evidence suggests that modulation of the large-conductance, calcium-activated potassium (BK) channel regulates auditory processing in the brain. Because ion channel expression often changes during aging, this could be a factor in age-related hearing loss. The current study explored how the novel BK channel modulator LS3 shapes central auditory processing in young and old adult mice. In vivo extracellular recordings in the auditory midbrain demonstrated that LS3 differentially modulates neural processing along the tonotopic axis. Though sound-evoked activity was reduced in the mid and ventral tonotopic regions, LS3 enhanced excitatory drive and sound-evoked responses for some neurons in the dorsal, low-frequency region. Behavioral assessment using acoustic reflex modification audiometry indicated improved tone salience following systemic LS3 administration. Moderation of these responses with aging correlated with an age-related decline in BK channel expression. These findings suggest that targeting the BK channel enhances responsivity to tonal sounds, providing the potential to improve hearing acuity and treat hearing loss.
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8
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Sun S, Kapolowicz MR, Richardson M, Metherate R, Zeng FG. Task-dependent effects of nicotine treatment on auditory performance in young-adult and elderly human nonsmokers. Sci Rep 2021; 11:13187. [PMID: 34162968 PMCID: PMC8222263 DOI: 10.1038/s41598-021-92588-z] [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: 02/15/2021] [Accepted: 06/03/2021] [Indexed: 11/30/2022] Open
Abstract
Electrophysiological studies show that nicotine enhances neural responses to characteristic frequency stimuli. Previous behavioral studies partially corroborate these findings in young adults, showing that nicotine selectively enhances auditory processing in difficult listening conditions. The present work extended previous work to include both young and older adults and assessed the nicotine effect on sound frequency and intensity discrimination. Hypotheses were that nicotine improves auditory performance and that the degree of improvement is inversely proportional to baseline performance. Young (19-23 years old) normal-hearing nonsmokers and elderly (61-80) nonsmokers with normal hearing between 500 and 2000 Hz received nicotine gum (6 mg) or placebo gum in a single-blind, randomized crossover design. Participants performed three experiments (frequency discrimination, frequency modulation identification, and intensity discrimination) before and after treatment. The perceptual differences were analyzed between pre- and post-treatment, as well as between post-treatment nicotine and placebo conditions as a function of pre-treatment baseline performance. Compared to pre-treatment performance, nicotine significantly improved frequency discrimination. Compared to placebo, nicotine significantly improved performance for intensity discrimination, and the improvement was more pronounced in the elderly with lower baseline performance. Nicotine had no effect on frequency modulation identification. Nicotine effects are task-dependent, reflecting possible interplays of subjects, tasks and neural mechanisms.
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Affiliation(s)
- Shuping Sun
- Department of Otolaryngology - Head and Neck Surgery, The First Affiliated Hospital, Zhengzhou University, Zhengzhou, 450052, Henan, China
- Center for Hearing Research, University of California Irvine, Irvine, CA, USA
| | | | - Matthew Richardson
- Center for Hearing Research, University of California Irvine, Irvine, CA, USA
| | - Raju Metherate
- Center for Hearing Research, University of California Irvine, Irvine, CA, USA
| | - Fan-Gang Zeng
- Center for Hearing Research, University of California Irvine, Irvine, CA, USA.
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Na G, Kwak SH, Jang SH, Noh HE, Kim J, Yang S, Jung J. Supplementary Effect of Choline Alfoscerate on Speech Recognition in Patients With Age-Related Hearing Loss: A Prospective Study in 34 Patients (57 Ears). Front Aging Neurosci 2021; 13:684519. [PMID: 34149400 PMCID: PMC8211767 DOI: 10.3389/fnagi.2021.684519] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 05/10/2021] [Indexed: 11/13/2022] Open
Abstract
To investigate the effect of choline alfoscerate (CA) on hearing amplification in patients with age related hearing loss, we performed a prospective case-control observational study from March 2016 to September 2020. We assessed patients with bilateral word recognition score (WRS) <50% using monosyllabic words. The patients were 65-85 years old, without any history of dementia, Alzheimer's disease, parkinsonism, or depression. After enrollment, all patients started using hearing aids (HA). The CA group received a daily dose of 800 mg CA for 11 months. We performed between-group comparisons of audiological data, including pure tone audiometry, WRS, HA fitting data obtained using real-ear measurement (REM), and the Abbreviated Profile of Hearing Aid benefit scores after treatment. After CA administration, the WRS improved significantly in the CA group (4.2 ± 8.3%), but deteriorated in the control group (-0.6 ± 8.1%, p = 0.035). However, there was no significant between-group difference in the change in pure tone thresholds and aided speech intelligibility index calculated from REM. These findings suggest that the difference in WRS was relevant to central speech understanding rather than peripheral audibility. Therefore, administering oral CA could effectively enrich listening comprehension in older HA users.
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Affiliation(s)
- Gina Na
- Department of Otorhinolaryngology, Yonsei University College of Medicine, Seoul, South Korea.,Department of Otorhinolaryngology, Ilsan Paik Hospital, Inje University College of Medicine, Goyang, South Korea
| | - Sang Hyun Kwak
- Department of Otorhinolaryngology, St. Vincent Hospital, College of Medicine, The Catholic University of Korea, Seoul, South Korea
| | - Seung Hyun Jang
- Department of Otorhinolaryngology, Yonsei University College of Medicine, Seoul, South Korea
| | - Hye Eun Noh
- Department of Otorhinolaryngology, Yonsei University College of Medicine, Seoul, South Korea
| | - Jungghi Kim
- Department of Otorhinolaryngology, Yonsei University College of Medicine, Seoul, South Korea
| | - SeungJoon Yang
- Department of Otorhinolaryngology, Yonsei University College of Medicine, Seoul, South Korea
| | - Jinsei Jung
- Department of Otorhinolaryngology, Yonsei University College of Medicine, Seoul, South Korea
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10
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Li X, Zhang D, Xu L, Han Y, Liu W, Li W, Fan Z, Costanzo RM, Strauss Iii JF, Zhang Z, Wang H. Planar cell polarity defects and hearing loss in sperm-associated antigen 6 ( Spag6)-deficient mice. Am J Physiol Cell Physiol 2021; 320:C132-C141. [PMID: 33175573 PMCID: PMC7846974 DOI: 10.1152/ajpcell.00166.2020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Spag6 encodes an axoneme central apparatus protein that is required for normal flagellar and cilia motility. Recent findings suggest that Spag6 also plays a role in ciliogenesis, orientation of cilia basal feet, and planar polarity. Sensory cells of the inner ear display unique structural features that underlie their mechanosensitivity. They represent a distinctive form of cellular polarity, known as planar cell polarity (PCP). However, a role for Spag6 in the inner ear has not yet been explored. In the present study, the function of Spag6 in the inner ear was examined using Spag6-deficient mice. Our results demonstrate hearing loss in the Spag6 mutants, associated with abnormalities in cellular patterning, cell shape, stereocilia bundles, and basal bodies, as well as abnormally distributed Frizzled class receptor 6 (FZD6), suggesting that Spag6 participates in PCP regulation. Moreover, we found that the subapical microtubule meshwork was disrupted. Our observations suggest new functions for Spag6 in hearing and PCP in the inner ear.
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Affiliation(s)
- Xiaofei Li
- Department of Otolaryngology-Head and Neck Surgery, Shandong Provincial ENT Hospital, Cheeloo College of Medicine, Shandong University, Jinan, People's Republic of China
| | - Daogong Zhang
- Department of Otolaryngology-Head and Neck Surgery, Shandong Provincial ENT Hospital, Cheeloo College of Medicine, Shandong University, Jinan, People's Republic of China
| | - Lei Xu
- Department of Otolaryngology-Head and Neck Surgery, Shandong Provincial ENT Hospital, Cheeloo College of Medicine, Shandong University, Jinan, People's Republic of China
| | - Yuechen Han
- Department of Otolaryngology-Head and Neck Surgery, Shandong Provincial ENT Hospital, Cheeloo College of Medicine, Shandong University, Jinan, People's Republic of China
| | - Wenwen Liu
- Department of Otolaryngology-Head and Neck Surgery, Shandong Provincial ENT Hospital, Cheeloo College of Medicine, Shandong University, Jinan, People's Republic of China
| | - Wei Li
- Department of Physiology, Wayne State University, Detroit, Michigan
| | - Zhaomin Fan
- Department of Otolaryngology-Head and Neck Surgery, Shandong Provincial ENT Hospital, Cheeloo College of Medicine, Shandong University, Jinan, People's Republic of China
| | - Richard M Costanzo
- Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, Virginia
| | - Jerome F Strauss Iii
- Department of Obstetrics and Gynecology, Virginia Commonwealth University, Richmond, Virginia
| | - Zhibing Zhang
- Department of Physiology, Wayne State University, Detroit, Michigan
- Department of Obstetrics and Gynecology, Wayne State University, Detroit, Michigan
| | - Haibo Wang
- Department of Otolaryngology-Head and Neck Surgery, Shandong Provincial ENT Hospital, Cheeloo College of Medicine, Shandong University, Jinan, People's Republic of China
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11
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Zhang J, Huang S, Nan W, Zhou H, Wang J, Wang H, Salvi R, Yin S. Switching Tinnitus-On: Maps and source localization of spontaneous EEG. Clin Neurophysiol 2020; 132:345-357. [PMID: 33450557 DOI: 10.1016/j.clinph.2020.10.023] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 10/05/2020] [Accepted: 10/11/2020] [Indexed: 10/22/2022]
Abstract
OBJECTIVE To identify the spectrotemporal changes and sources in patients that could "turn on" tinnitus with multichannel electroencephalography (EEG) system. METHODS Multichannel EEG was recorded from six patients during the Tinnitus-On and Tinnitus-Off states. The EEG power spectrum and eLORETA-based sources were measured. RESULTS There was a global increase in delta and theta during Tinnitus-On plus large changes in alpha 1 and alpha 2. During the Tinnitus-On state, many new sources in delta, theta, alpha 1 and gamma bands emerged in the opposite hemisphere in the inferior temporal gyrus (Brodmann area, BA 20), middle temporal gyrus (BA 21), lateral perirhinal cortex (BA 36), ventral entorhinal cortex (BA 28) and anterior pole of the temporal gyrus (BA 38). CONCLUSIONS The emergence of new delta, theta and gamma band sources in the inferior temporal gyrus (BA 20), middle temporal gyrus (BA 21) and lateral perirhinal cortex (BA 36) plus the appearance of new delta and theta sources in the ventral entorhinal cortex (BA28) and anterior pole of the temporal lobe (BA 38) may comprise a network capable of evoking the phantom sound of tinnitus by simultaneously engaging brain regions involved in memory, sound recognition, and distress which together contribute to tinnitus severity. SIGNIFICANCE The sudden appearance of new sources of activity in the opposite hemisphere within the inferior temporal gyrus, middle temporal gyrus and perirhinal cortex may initiate the perception of tinnitus perception.
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Affiliation(s)
- Jiajia Zhang
- Department of Otolaryngology-Head and Neck Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 600 Yishan Road, Shanghai 200233, China; Otolaryngology Institute of Shanghai Jiao Tong University, Shanghai 200233, China; Shanghai Key Laboratory of Sleep Disordered Breathing, Shanghai 200233, China
| | - Shujian Huang
- Department of Otolaryngology-Head and Neck Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 600 Yishan Road, Shanghai 200233, China; Otolaryngology Institute of Shanghai Jiao Tong University, Shanghai 200233, China; Shanghai Key Laboratory of Sleep Disordered Breathing, Shanghai 200233, China
| | - Wenya Nan
- Department of Psychology, Shanghai Normal University, Shanghai 200234, China
| | - Huiqun Zhou
- Department of Otolaryngology-Head and Neck Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 600 Yishan Road, Shanghai 200233, China; Otolaryngology Institute of Shanghai Jiao Tong University, Shanghai 200233, China; Shanghai Key Laboratory of Sleep Disordered Breathing, Shanghai 200233, China.
| | - Jian Wang
- School of Communication Science and Disorders, Dalhousie University, Halifax, Canada
| | - Hui Wang
- Department of Otolaryngology-Head and Neck Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 600 Yishan Road, Shanghai 200233, China; Otolaryngology Institute of Shanghai Jiao Tong University, Shanghai 200233, China; Shanghai Key Laboratory of Sleep Disordered Breathing, Shanghai 200233, China.
| | - Richard Salvi
- SUNY Distinguished Professor Center for Hearing and Deafness, 137 Cary Hall, University at Buffalo, Buffalo, NY, USA
| | - Shankai Yin
- Department of Otolaryngology-Head and Neck Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 600 Yishan Road, Shanghai 200233, China; Otolaryngology Institute of Shanghai Jiao Tong University, Shanghai 200233, China; Shanghai Key Laboratory of Sleep Disordered Breathing, Shanghai 200233, China
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12
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Gao D, Yu H, Li B, Chen L, Li X, Gu W. Cisplatin Toxicology: The Role of Pro-inflammatory Cytokines and GABA Transporters in Cochlear Spiral Ganglion. Curr Pharm Des 2020; 25:4820-4826. [PMID: 31692421 DOI: 10.2174/1381612825666191106143743] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 11/01/2019] [Indexed: 12/20/2022]
Abstract
Background:
The current study was conducted to examine the specific activation of pro-inflammatory
cytokines (PICs), namely IL-1β, IL-6 and TNF-α in the cochlear spiral ganglion of rats after ototoxicity induced
by cisplatin. Since γ-aminobutyric acid (GABA) and its receptors are involved in pathophysiological processes of
ototoxicity, we further examined the role played by PICs in regulating expression of GABA transporter type 1
and 3 (GAT-1 and GAT-3), as two essential subtypes of GATs responsible for the regulation of extracellular
GABA levels in the neuronal tissues.
Methods:
ELISA and western blot analysis were employed to examine the levels of PICs and GATs; and auditory
brainstem response was used to assess ototoxicity induced by cisplatin.
Results:
IL-1β, IL-6 and TNF-α as well as their receptors were significantly increased in the spiral ganglion of
ototoxic rats as compared with sham control animals (P<0.05, ototoxic rats vs. control rats). Cisplatin-ototoxicity
also induced upregulation of the protein levels of GAT-1 and GAT-3 in the spiral ganglion (P<0.05 vs. controls).
In addition, administration of inhibitors to IL-1β, IL-6 and TNF-α attenuated amplification of GAT-1 and GAT-3
and improved hearing impairment induced by cisplatin.
Conclusion:
Our data indicate that PIC signals are activated in the spiral ganglion during cisplatin-ototoxicity
which thereby leads to upregulation of GABA transporters. As a result, it is likely that de-inhibition of GABA
system is enhanced in the cochlear spiral ganglion. This supports a role for PICs in engagement of the signal
mechanisms associated with cisplatin-ototoxicity, and has pharmacological implications to target specific PICs
for GABAergic dysfunction and vulnerability related to cisplatin-ototoxicity.
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Affiliation(s)
- Dongmei Gao
- Department of Otorhinolaryngology, The First Hospital of Jilin University, Changchun, Jilin 130021, China
| | - Hong Yu
- Department of Otorhinolaryngology, The First Hospital of Jilin University, Changchun, Jilin 130021, China
| | - Bo Li
- Department of Rehabilitation, China-Japan Union Hospital of Jilin University, Changchun, Jilin 130033, China
| | - Li Chen
- Hospital of Stomatology, Jilin University, Changchun, Jilin 130000, China
| | - Xiaoyu Li
- Department of Otorhinolaryngology, The First Hospital of Jilin University, Changchun, Jilin 130021, China
| | - Wenqing Gu
- Department of Otorhinolaryngology, The First Hospital of Jilin University, Changchun, Jilin 130021, China
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13
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Kaur C, Saini S, Pal I, Kumar P, Chandra Sati H, Jacob TG, Bhardwaj DN, Roy TS. Age-related changes in the number of cresyl-violet-stained, parvalbumin and NMDAR 2B expressing neurons in the human spiral ganglion. Hear Res 2020; 388:107883. [PMID: 31981822 DOI: 10.1016/j.heares.2020.107883] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 12/12/2019] [Accepted: 12/31/2019] [Indexed: 01/11/2023]
Abstract
Animal-studies associate age-related hearing loss (presbycusis) with decreasing number of spiral ganglion neurons (SGNs) in Rosenthal's canal (RC) of cochlea. The excitatory neurotransmitter for SGNs is glutamate (through its receptor NMDAR 2B), which can be neurotoxic through Ca2+ overload. Neurotoxicity is balanced by calcium-binding proteins (CBPs) like Parvalbumin (PV), which is the predominant CBP of the SGNs. To estimate the volume of the RC and total number of SGNs that are immunoreactive to PV and NMDAR 2B, we used unbiased stereology in 35 human cochleae derived from cadavers of persons from 2nd to 8th decade of life (subsequently statistically divided into two groups) and compared them to the total number of cresyl violet (CV) stained SGNs. We also estimated the volume of individual neurons and their nuclei. Regression analysis was made on estimated parameters against age. Hierarchical-cluster analysis was done on the neuronal against neuronal nuclear volumes.The average volume of the RC did not change with increasing age (p = 0.4115). The total number of SGNs (CV-stained and those separately expressing PV and NMDAR 2B) significantly decreased with age (p < 0.001). We identified three distinct populations of neurons on the basis of their volumes among SGNs. Thus, there is significant age-related decline in the total number of SGNs, which starts early in life. It may be due to ambient noise and inadequate neutralisation of excitotoxicity.
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Affiliation(s)
- Charanjeet Kaur
- Department of Anatomy, All India Institute of Medical Sciences, New Delhi, 110029, India.
| | - Shubhi Saini
- Department of Anatomy, All India Institute of Medical Sciences, New Delhi, 110029, India.
| | - Indra Pal
- Department of Anatomy, All India Institute of Medical Sciences, New Delhi, 110029, India.
| | - Punit Kumar
- Department of Anatomy, All India Institute of Medical Sciences, New Delhi, 110029, India.
| | - Hem Chandra Sati
- Department of Biostatistics, All India Institute of Medical Sciences, New Delhi, 110029, India.
| | - Tony George Jacob
- Department of Anatomy, All India Institute of Medical Sciences, New Delhi, 110029, India.
| | - Daya Nand Bhardwaj
- Department of Forensic Medicine and Toxicology, All India Institute of Medical Sciences, New Delhi, 110029, India.
| | - Tara Sankar Roy
- Department of Anatomy, All India Institute of Medical Sciences, New Delhi, 110029, India.
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14
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Ali W, Shar NA. Molecular docking analysis of timepidium with Acetylcholine and lumacaftor with GABA(A) activator. Bioinformation 2019; 15:832-837. [PMID: 31902984 PMCID: PMC6936661 DOI: 10.6026/97320630015832] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 12/10/2019] [Accepted: 12/11/2019] [Indexed: 12/12/2022] Open
Abstract
Epilepsy is a chronic disorder characterized by disturbed tissue related molecular activity within the brain irrespective of age. The cause is very difficult to understand towards a suitable treatment. However, its symptoms like seizures are treated and suppressed by known medications. Moreover, the condition is linked with neuro-transmitters such as GABA (gamma amino butyric acid) and acetylcholine. Therefore, it is of interest to design and develop inhibitors for these targets. Hence, we describe the molecular binding features of timepidium with acetylcholine and lumacaftor with GABA(A) activator using molecular docking based geometric optimization and screening analysis for further consideration.
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Affiliation(s)
- Warda Ali
- Department of Biomedical Engineering, NED University of Engineering and Technology Karachi, Pakistan
| | - Nisar A Shar
- Department of Biomedical Engineering, NED University of Engineering and Technology Karachi, Pakistan
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15
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Jafari Z, Kolb BE, Mohajerani MH. Age-related hearing loss and tinnitus, dementia risk, and auditory amplification outcomes. Ageing Res Rev 2019; 56:100963. [PMID: 31557539 DOI: 10.1016/j.arr.2019.100963] [Citation(s) in RCA: 94] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 08/20/2019] [Accepted: 09/18/2019] [Indexed: 01/07/2023]
Abstract
Age-related hearing loss (ARHL) or presbycusis, as the third leading cause of chronic disability in older adults, has been shown to be associated with predisposing cognitive impairment and dementia. Tinnitus is also a chronic auditory disorder demonstrating a growth rate with increasing age. Recent evidence stands for the link between bothersome tinnitus and impairments in various aspects of cognitive function. Both ARHL and age-related tinnitus affect mental health and contribute to developing anxiety, stress, and depression. The present review is a comprehensive multidisciplinary study on diverse interactions among ARHL, tinnitus, and cognitive decline in older adults. This review incorporates the latest evidence in prevalence and risk factors of ARHL and tinnitus, the neural substrates of tinnitus-related cognitive impairments, hypothesized mechanisms concerning the association between ARHL and increased risk of dementia, hearing amplification outcomes in cases with ARHL and cognitive decline, and preliminary findings on the link between ARHL and cognitive impairment in animal studies. Given extensive evidence that demonstrates advantages of using auditory amplification in the alleviation of hearing handicap, depression, and tinnitus, and the improvement of cognition, social communication, and quality of life, regular hearing screening programs for identification and management of midlife hearing loss and tinnitus is strongly recommended.
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16
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Lalwani P, Gagnon H, Cassady K, Simmonite M, Peltier S, Seidler RD, Taylor SF, Weissman DH, Polk TA. Neural distinctiveness declines with age in auditory cortex and is associated with auditory GABA levels. Neuroimage 2019; 201:116033. [PMID: 31326572 DOI: 10.1016/j.neuroimage.2019.116033] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 07/17/2019] [Accepted: 07/17/2019] [Indexed: 12/31/2022] Open
Abstract
Neural activation patterns in the ventral visual cortex in response to different categories of visual stimuli (e.g., faces vs. houses) are less selective, or distinctive, in older adults than in younger adults, a phenomenon known as age-related neural dedifferentiation. In this study, we investigated whether neural dedifferentiation extends to the auditory cortex. Inspired by previous animal work, we also investigated whether individual differences in GABA are associated with individual differences in neural distinctiveness in humans. 20 healthy young adults (ages 18-29) and 23 healthy older adults (over 65) completed a functional magnetic resonance imaging (fMRI) scan, during which neural activity was estimated while they listened to music and foreign speech. GABA levels in the auditory, ventrovisual and sensorimotor cortex were estimated in the same individuals in a separate magnetic resonance spectroscopy (MRS) scan. Relative to the younger adults, the older adults exhibited both (1) less distinct activation patterns for music vs. speech stimuli and (2) lower GABA levels in the auditory cortex. Also, individual differences in auditory GABA levels (but not ventrovisual or sensorimotor GABA levels) were associated with individual differences in neural distinctiveness in the auditory cortex in the older adults. These results demonstrate that age-related neural dedifferentiation extends to the auditory cortex and suggest that declining GABA levels may play a role in neural dedifferentiation in older adults.
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Affiliation(s)
- Poortata Lalwani
- Department of Psychology, University of Michigan, Ann Arbor, MI, 48109, USA.
| | - Holly Gagnon
- Department of Psychology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Kaitlin Cassady
- Department of Psychology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Molly Simmonite
- Department of Psychology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Scott Peltier
- Department of Bioengineering, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Rachael D Seidler
- Department of Applied Physiology & Kinesiology, University of Florida, Gainesville, FL, 32611, USA
| | - Stephan F Taylor
- Department of Psychology, University of Michigan, Ann Arbor, MI, 48109, USA; Department of Psychiatry, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Daniel H Weissman
- Department of Psychology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Thad A Polk
- Department of Psychology, University of Michigan, Ann Arbor, MI, 48109, USA
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17
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Liu P, Qin D, Huang X, Chen H, Ye W, Lin X, Su J. Neurotoxicity of sodium salicylate to the spiral ganglion neurons: GABA A receptor regulates NMDA receptor by Fyn-dependent phosphorylation. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2019; 205:469-479. [PMID: 31020389 DOI: 10.1007/s00359-019-01339-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Revised: 04/12/2019] [Accepted: 04/15/2019] [Indexed: 11/25/2022]
Abstract
The purpose of this study was to observe the regulatory effects of GABAA (γ-aminobutyric acid A) receptor on the N-methyl-D-aspartate (NMDA) receptor during excitotoxicity in spiral ganglion neurons in the rat cochlea induced by sodium salicylate (SS). Western blot illustrated SS decreased the expression of NMDA receptor 2B subunit (NR2B) surface protein through affecting GABAA receptor, but the total protein content did not significantly change. Y1472 and S1480 are important phosphorylation sites in NR2B, SS downregulated the Fyn-dependent phosphorylation of Y1472 in a manner not related to the CK2 (Casein Kinase 2) dependent phosphorylation of S1480, thus regulating the surface distribution and internalization of NMDA receptor through GABAA receptor. These results suggest that the modified pattern of dynamic balance between excitation and inhibition by coactivation of the GABAA receptor can attenuate the excitatory NMDA receptor under the action of SS, via inhibiting the Fyn-dependent phosphorylation of Y1472.
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Affiliation(s)
- Peiqiang Liu
- Department of Otolaryngology-Head and Neck Surgery, First Affiliated Hospital of Guangxi Medical University, Nanning, 530021, Guangxi, China
| | - Danxue Qin
- Department of Otolaryngology-Head and Neck Surgery, First Affiliated Hospital of Guangxi Medical University, Nanning, 530021, Guangxi, China
| | - Xi Huang
- Department of Otolaryngology-Head and Neck Surgery, First Affiliated Hospital of Guangxi Medical University, Nanning, 530021, Guangxi, China
- Department of Otolaryngology-Head and Neck Surgery, Wuhan No. 1 Hospital, Wuhan, 430022, Hubei, China
| | - Huiying Chen
- Department of Otolaryngology-Head and Neck Surgery, First Affiliated Hospital of Guangxi Medical University, Nanning, 530021, Guangxi, China
| | - Wenhua Ye
- Department of Otolaryngology-Head and Neck Surgery, First Affiliated Hospital of Guangxi Medical University, Nanning, 530021, Guangxi, China
| | - Xiaoyu Lin
- Department of Otolaryngology-Head and Neck Surgery, First Affiliated Hospital of Guangxi Medical University, Nanning, 530021, Guangxi, China
| | - Jiping Su
- Department of Otolaryngology-Head and Neck Surgery, First Affiliated Hospital of Guangxi Medical University, Nanning, 530021, Guangxi, China.
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18
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Kommajosyula SP, Cai R, Bartlett E, Caspary DM. Top-down or bottom up: decreased stimulus salience increases responses to predictable stimuli of auditory thalamic neurons. J Physiol 2019; 597:2767-2784. [PMID: 30924931 DOI: 10.1113/jp277450] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Accepted: 03/25/2019] [Indexed: 01/29/2023] Open
Abstract
KEY POINTS Temporal imprecision leads to deficits in the comprehension of signals in cluttered acoustic environments, and the elderly are shown to use cognitive resources to disambiguate these signals. To mimic ageing in young rats, we delivered sound signals that are temporally degraded, which led to temporally imprecise neural codes. Instead of adaptation to repeated stimuli, with degraded signals, there was a relative increase in firing rates, similar to that seen in aged rats. We interpret this increase with repetition as a repair mechanism for strengthening the internal representations of degraded signals by the higher-order structures. ABSTRACT To better understand speech in challenging environments, older adults increasingly use top-down cognitive and contextual resources. The medial geniculate body (MGB) integrates ascending inputs with descending predictions to dynamically gate auditory representations based on salience and context. A previous MGB single-unit study found an increased preference for predictable sinusoidal amplitude modulated (SAM) stimuli in aged rats relative to young rats. The results suggested that the age-degraded/jittered up-stream acoustic code may engender an increased preference for predictable/repeating acoustic signals, possibly reflecting increased use of top-down resources. In the present study, we recorded from units in young-adult MGB, comparing responses to standard SAM with those evoked by less salient SAM (degraded) stimuli. We hypothesized that degrading the SAM stimulus would simulate the degraded ascending acoustic code seen in the elderly, increasing the preference for predictable stimuli. Single units were recorded from clusters of advanceable tetrodes implanted above the MGB of young-adult awake rats. Less salient SAM significantly increased the preference for predictable stimuli, especially at higher modulation frequencies. Rather than adaptation, higher modulation frequencies elicited increased numbers of spikes with each successive trial/repeat of the less salient SAM. These findings are consistent with previous findings obtained in aged rats suggesting that less salient acoustic signals engage the additional use of top-down resources, as reflected by an increased preference for repeating stimuli that enhance the representation of complex environmental/communication sounds.
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Affiliation(s)
- Srinivasa P Kommajosyula
- Southern Illinois University School of Medicine, , Department of Pharmacology, Springfield, IL, USA
| | - Rui Cai
- Southern Illinois University School of Medicine, , Department of Pharmacology, Springfield, IL, USA
| | - Edward Bartlett
- Department of Biological Sciences, Purdue University, West Lafayette, IN, USA
| | - Donald M Caspary
- Southern Illinois University School of Medicine, , Department of Pharmacology, Springfield, IL, USA
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Fan H, Ji M, Huang J, Yue P, Yang X, Wang C, Ying W. Development and validation of a dynamic delirium prediction rule in patients admitted to the Intensive Care Units (DYNAMIC-ICU): A prospective cohort study. Int J Nurs Stud 2019; 93:64-73. [PMID: 30861455 DOI: 10.1016/j.ijnurstu.2018.10.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Revised: 10/09/2018] [Accepted: 10/10/2018] [Indexed: 11/26/2022]
Abstract
BACKGROUND Delirium is one of the most common cognitive complications among patients admitted to the intensive care units (ICU). OBJECTIVE To develop and validate a DYNAmic deliriuM predICtion rule for ICU patients (DYNAMIC-ICU) and to stratify patients into different risk levels among patients in various types of ICUs. DESIGN Prospective cohort study. SETTING AND PARTICIPANTS A total of 560 (median age of 66 years, 62.5% male) consecutively enrolled patients from four ICUs were included in the study. The patients were randomly assigned into either the derivation (n = 336, 60%) or the validation (n = 224, 40%) cohort by stratified randomization based on delirium/non-delirium and types of ICU. METHODS The simplified Chinese version of the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) was used to assess delirium until patients were discharged from the ICUs. Potential predisposing, disease-related, and iatrogenic and environmental risk factors as well as data on patients' outcomes were collected prospectively. RESULTS Of the enrolled patients, 20.2% and 20.5% developed delirium in the derivation and validation cohorts, respectively. Predisposing factors (history of chronic diseases, hearing deficits), disease-related factors (infection, higher APACHE II scores at admission), and iatrogenic and environmental factors (the use of sedatives and analgesics, indwelling catheter, and sleep disturbance) were identified as independent predictors of delirium. Points were assigned to each predictor according to their odds ratio to create a prediction rule which was internally validated based on total scores and by bootstrapping (AUCs of 0.907 [95% CI 0. 871 -0.944], 0.888 [95% CI 0.845-0.932], and 0.874 [95% CI 0.828-0.920]), respectively. The total score of the DYNAMIC-ICU ranged from 0 to 33 and patients were divided into low risk (0-9), moderate risk (10-17), high risk (18-33) groups in developing delirium according to their total score with incidence of delirium at 2.8%, 16.8% and 75.9% in the derivation group, respectively. The DYNAMIC-ICU and its performance of risk level stratification were further validated in the validation cohort (AUC = 0.900 [95% CI 0.858-0.941]). The all-cause mortality was increased and the length of hospital stay was prolonged dramatically with the increase of delirium risk levels in both derivation (p = 0.034, p < 0.001) and validation cohorts (p < 0.001, p < 0.001). CONCLUSIONS Seven predictors for ICU delirium were identified to create DYNAMIC-ICU, which could well stratify ICU patients into three different delirium risk levels, tailor risk level changes, and predict in-hospital outcomes by a dynamic assessment approach.
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Affiliation(s)
- Huan Fan
- School of Nursing, Capital Medical University, Beijing, China
| | - Meihua Ji
- School of Nursing, Capital Medical University, Beijing, China
| | - Jie Huang
- Beijing Jishuitan Hospital,Capital Medical University, Beijing, China
| | - Peng Yue
- School of Nursing, Capital Medical University, Beijing, China
| | - Xin Yang
- Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Chunli Wang
- Beijing Children's Hospital, Capital Medical University, Beijing, China
| | - Wu Ying
- School of Nursing, Capital Medical University, Beijing, China.
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20
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Utkin YN. Aging Affects Nicotinic Acetylcholine Receptors in Brain. Cent Nerv Syst Agents Med Chem 2019; 19:119-124. [PMID: 30894113 DOI: 10.2174/1871524919666190320102834] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 02/28/2019] [Accepted: 03/08/2019] [Indexed: 06/09/2023]
Abstract
BACKGROUND Aging is a common and inevitable stage in the life cycle of higher organisms. Different organs, including the central nervous system, are affected by aging in different ways. Many processes are involved in aging, and neurodegeneration is one of the aging processes in which the central nervous system is engaged. Brain degeneration during normal aging underlies cognitive disorders experienced by older people. Not all molecular mechanisms associated with age-related neurodegeneration are fully understood; however, there is a whole range of data on the participation of nicotinic acetylcholine receptors in the processes of aging and neurodegeneration. Two main subtypes of nicotinic acetylcholine receptor α7 and α4β2 present in the central nervous system are affected by these processes. The loss of these receptor subtypes during normal aging is one of the reasons for the cognitive impairments. The decrease in nicotinic acetylcholine receptors is also very important for the pathogenesis of age-related neurodegenerative diseases. Thus, the drugs enhancing receptor functions may be considered promising for the treatment of cognitive dysfunction in the aged people. CONCLUSION To achieve healthy longevity, the molecular processes that occur during aging should be established. In this regard, the participation and role of nicotinic acetylcholine receptors in the brain aging and degeneration are considered in this review.
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Affiliation(s)
- Yuri N Utkin
- Laboratory of Molecular Toxinology, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry RAS, Moscow, Russian Federation
- National University of Science and Technology MISIS, 119049 Moscow, Russian Federation
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21
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Dong Y, Guo CR, Chen D, Chen SM, Peng Y, Song H, Shi JR. Association between age‑related hearing loss and cognitive decline in C57BL/6J mice. Mol Med Rep 2018; 18:1726-1732. [PMID: 29901198 DOI: 10.3892/mmr.2018.9118] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Accepted: 09/15/2017] [Indexed: 11/06/2022] Open
Abstract
Accumulating evidence has revealed the link between age‑related hearing loss (presbycusis) and cognitive decline; however, their exact association remains unclear. The present study aimed to investigate the association between age‑related hearing loss and cognitive decline, and to explore the underlying mechanisms. Briefly, three groups of C57BL/6J mice were evaluated, based on their age, as follows: Young group, 3 months; adult group, 6 months; and middle‑aged group, 15 months. The results of an auditory brainstem response (ABR) test demonstrated that the hearing threshold levels of the mice were increased in those aged 6 and 15 months compared with those aged 3 months, thus suggesting that significant hearing loss occurred at 6 months, and worsened at 15 months. The results of a Morris water maze test demonstrated that spatial learning and memory function was significantly decreased in 15‑month‑old mice, but not in 6‑month‑old mice. Pearson analysis indicated that the escape latency was positively correlated with hearing threshold at 16 kHz and percentage of time in the target quadrant was negatively correlated with hearing threshold at 16 kHz, thus suggesting a correlation between age‑related hearing loss and cognitive decline. The auditory cortex and hippocampal CA1 region in 15‑month‑old mice exhibited significantly decreased cell numbers, abnormal arrangement and morphological alterations. Transmission electron microscopy revealed reduced synapse numbers and synaptic vesicle density in mice aged 15 months. Furthermore, the protein expression levels of matrix metalloproteinase (MMP)‑9 in the auditory cortex and hippocampus in the 15‑month‑old mice were significantly higher than in the 3‑month‑old mice. In conclusion, these findings support the correlation between age‑related hearing loss and cognitive decline in C57BL/6J mice, and indicated that MMP‑9 expression in the auditory cortex and hippocampus may be associated with the underlying mechanisms.
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Affiliation(s)
- Yang Dong
- Experimental Teaching Center, Basic Medical College, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, P.R. China
| | - Chun-Rong Guo
- Experimental Teaching Center, Basic Medical College, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, P.R. China
| | - Dan Chen
- Experimental Teaching Center, Basic Medical College, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, P.R. China
| | - Sheng-Min Chen
- Experimental Teaching Center, Basic Medical College, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, P.R. China
| | - Yinting Peng
- Experimental Teaching Center, Basic Medical College, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, P.R. China
| | - Haiyan Song
- Central Lab, Basic Medical College, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, P.R. China
| | - Jian-Rong Shi
- Experimental Teaching Center, Basic Medical College, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, P.R. China
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22
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Pre- and postsynaptic ionotropic glutamate receptors in the auditory system of mammals. Hear Res 2018; 362:1-13. [DOI: 10.1016/j.heares.2018.02.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 02/16/2018] [Accepted: 02/21/2018] [Indexed: 01/22/2023]
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23
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Chronic cigarette smoke exposure drives spiral ganglion neuron loss in mice. Sci Rep 2018; 8:5746. [PMID: 29636532 PMCID: PMC5893541 DOI: 10.1038/s41598-018-24166-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 03/28/2018] [Indexed: 02/07/2023] Open
Abstract
Tobacco use is associated with an increased risk of hearing loss in older individuals, suggesting cigarette smoke (CS) exposure may target the peripheral auditory organs. However, the effects of CS exposure on general cochlear anatomy have not previously been explored. Here we compare control and chronic CS exposed cochleae from adult mice to assess changes in structure and cell survival. Two-photon imaging techniques, including the imaging of second harmonic generation (SHG) and two-photon excitation fluorescence (TPEF) from native molecules, were used to probe the whole cochlear organ for changes. We found evidence for fibrillar collagen accumulation in the spiral ganglion and organ of Corti, consistent with fibrosis. Quantitative TPEF indicated that basal CS-exposed spiral ganglion neurons experienced greater oxidative stress than control neurons, which was confirmed by histological staining for lipid peroxidation products. Cell counts confirmed that the CS-exposed spiral ganglion also contained fewer basal neurons. Taken together, these data support the premise that CS exposure induces oxidative stress in cochlear cells. They also indicate that two-photon techniques may screen cochlear tissues for oxidative stress.
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Cai R, Montgomery SC, Graves KA, Caspary DM, Cox BC. The FBN rat model of aging: investigation of ABR waveforms and ribbon synapse changes. Neurobiol Aging 2018; 62:53-63. [PMID: 29107847 PMCID: PMC5743589 DOI: 10.1016/j.neurobiolaging.2017.09.034] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Revised: 09/22/2017] [Accepted: 09/30/2017] [Indexed: 01/25/2023]
Abstract
Age-related hearing loss is experienced by one-third of individuals aged 65 years and older and can be socially debilitating. Historically, there has been poor correlation between age-related threshold changes, loss of speech understanding, and loss of cochlear hair cells. We examined changes in ribbon synapse number at four different ages in Fisher Brown Norway rats, an extensively studied rat model of aging. In contrast to previous work in mice/Wistar rats, we found minimal ribbon synapse loss before 20 months, with significant differences in 24- and 28-month-old rats at 4 kHz. Significant outer HC loss was observed at 24 and 28 months in low- to mid-frequency regions. Age-related reductions in auditory brainstem response wave I amplitude and increases in threshold were strongly correlated with ribbon synapse loss. Wave V/I ratios increased across age for click, 2, 4, and 24 kHz. Together, we find that ribbon synapses in the Fisher Brown Norway rat cochlea show resistance to aging until ∼60% of their life span, suggesting species/strain differences may underpin decreased peripheral input into the aging central processor.
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Affiliation(s)
- Rui Cai
- Division of Otolaryngology, Department of Pharmacology, Southern Illinois University School of Medicine, Springfield, IL, USA
| | - Scott C Montgomery
- Division of Otolaryngology, Department of Pharmacology, Southern Illinois University School of Medicine, Springfield, IL, USA; Division of Otolaryngology, Department of Surgery, Southern Illinois University School of Medicine, Springfield, IL, USA
| | - Kaley A Graves
- Division of Otolaryngology, Department of Pharmacology, Southern Illinois University School of Medicine, Springfield, IL, USA
| | - Donald M Caspary
- Division of Otolaryngology, Department of Pharmacology, Southern Illinois University School of Medicine, Springfield, IL, USA; Division of Otolaryngology, Department of Surgery, Southern Illinois University School of Medicine, Springfield, IL, USA.
| | - Brandon C Cox
- Division of Otolaryngology, Department of Pharmacology, Southern Illinois University School of Medicine, Springfield, IL, USA; Division of Otolaryngology, Department of Surgery, Southern Illinois University School of Medicine, Springfield, IL, USA.
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25
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Frisina RD, Ding B, Zhu X, Walton JP. Age-related hearing loss: prevention of threshold declines, cell loss and apoptosis in spiral ganglion neurons. Aging (Albany NY) 2017; 8:2081-2099. [PMID: 27667674 PMCID: PMC5076453 DOI: 10.18632/aging.101045] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Accepted: 09/08/2016] [Indexed: 12/18/2022]
Abstract
Age-related hearing loss (ARHL) -presbycusis - is the most prevalent neurodegenerative disease and number one communication disorder of our aged population; and affects hundreds of millions of people worldwide. Its prevalence is close to that of cardiovascular disease and arthritis, and can be a precursor to dementia. The auditory perceptual dysfunction is well understood, but knowledge of the biological bases of ARHL is still somewhat lacking. Surprisingly, there are no FDA-approved drugs for treatment. Based on our previous studies of human subjects, where we discovered relations between serum aldosterone levels and the severity of ARHL, we treated middle age mice with aldosterone, which normally declines with age in all mammals. We found that hearing thresholds and suprathreshold responses significantly improved in the aldosterone-treated mice compared to the non-treatment group. In terms of cellular and molecular mechanisms underlying this therapeutic effect, additional experiments revealed that spiral ganglion cell survival was significantly improved, mineralocorticoid receptors were upregulated via post-translational protein modifications, and age-related intrinsic and extrinsic apoptotic pathways were blocked by the aldosterone therapy. Taken together, these novel findings pave the way for translational drug development towards the first medication to prevent the progression of ARHL.
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Affiliation(s)
- Robert D Frisina
- Department Communication Sciences and Disorders, Global Center for Hearing and Speech Research, University of South Florida, Tampa FL, 33612, USA.,Department Chemical and Biomedical Engineering, Global Center for Hearing and Speech Research, University of South Florida, Tampa FL, 33612, USA
| | - Bo Ding
- Department Communication Sciences and Disorders, Global Center for Hearing and Speech Research, University of South Florida, Tampa FL, 33612, USA
| | - Xiaoxia Zhu
- Department Chemical and Biomedical Engineering, Global Center for Hearing and Speech Research, University of South Florida, Tampa FL, 33612, USA
| | - Joseph P Walton
- Department Communication Sciences and Disorders, Global Center for Hearing and Speech Research, University of South Florida, Tampa FL, 33612, USA.,Department Chemical and Biomedical Engineering, Global Center for Hearing and Speech Research, University of South Florida, Tampa FL, 33612, USA
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Changes in GABAergic markers accompany degradation of neuronal function in the primary visual cortex of senescent rats. Sci Rep 2017; 7:14897. [PMID: 29097694 PMCID: PMC5668371 DOI: 10.1038/s41598-017-15006-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Accepted: 10/19/2017] [Indexed: 11/14/2022] Open
Abstract
Numerous studies have reported age-dependent degradation of neuronal function in the visual cortex and have attributed this functional decline to weakened intracortical inhibition, especially GABAergic inhibition. However, whether this type of functional decline is linked to compromised GABAergic inhibition has not been fully confirmed. Here, we compared the neuronal response properties and markers of GABAergic inhibition in the primary visual cortex (V1) of young adult and senescent rats. Compared with those of young adult rats, old rats’ V1 neurons exhibited significantly increased visually evoked responses and spontaneous activity, a decreased signal-to-noise ratio and reduced response selectivity for the stimulus orientation and motion direction. Additionally, the ratio of GABA-positive neurons to total cortical neurons in old rats was significantly decreased compared with that in young rats. Expression of the key GABA-synthesizing enzyme GAD67 was significantly lower in old rats than in young rats, although GAD65 expression showed a marginal difference between the two age groups. Further, expression of an important GABAA receptor subunit, GABAAR α1, was significantly attenuated in old rats relative to young ones. These results demonstrate that ageing may result in decreased GABAergic inhibition in the visual cortex and that this decrease in GABAergic inhibition accompanies neuronal function degradation.
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Responses to Predictable versus Random Temporally Complex Stimuli from Single Units in Auditory Thalamus: Impact of Aging and Anesthesia. J Neurosci 2017; 36:10696-10706. [PMID: 27733619 DOI: 10.1523/jneurosci.1454-16.2016] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Accepted: 08/27/2016] [Indexed: 12/12/2022] Open
Abstract
Human aging studies suggest that an increased use of top-down knowledge-based resources would compensate for degraded upstream acoustic information to accurately identify important temporally rich signals. Sinusoidal amplitude-modulated (SAM) stimuli have been used to mimic the fast-changing temporal features in speech and species-specific vocalizations. Single units were recorded from auditory thalamus [medial geniculate body (MGB)] of young awake, aged awake, young anesthetized, and aged anesthetized rats. SAM stimuli were modulated between 2 and 1024 Hz with the modulation frequency (fm) changed randomly (RAN) across trials or sequentially (SEQ) after several repeated trials. Units were found to be RAN-preferring, SEQ-preferring, or nonselective based on total firing rate. Significant anesthesia and age effects were found. The majority (86%) of young anesthetized units preferred RAN SAM stimuli; significantly fewer young awake units (51%, p < 0.0001) preferred RAN SAM signals with 16% preferring SEQ SAM. Compared with young awake units, there was a significant increase of aged awake units preferring SEQ SAM (30%, p < 0.05). We examined RAN versus SEQ differences across fms by measuring selective fm areas under the rate modulation transfer function curve. The largest age-related differences from awake animals were found for mid-to-high fms in MGB units, with young units preferring RAN SAM while aged units showed a greater preference for SEQ-presented SAM. Together, these findings suggest that aged MGB units/animals employ increased top-down mediated stimulus context to enhance processing of "expected" temporally rich stimuli, especially at more challenging higher fms. SIGNIFICANCE STATEMENT Older individuals compensate for impaired ascending acoustic information by increasing use of cortical cognitive and attentional resources. The interplay between ascending and descending influences in the thalamus may serve to enhance the salience of speech signals that are degraded as they ascend to the cortex. The present findings demonstrate that medial geniculate body units from awake rats show an age-related preference for predictable modulated signals relative to randomly presented signals, especially at higher, more challenging modulation frequencies. Conversely, units from anesthetized animals, with little top-down influences, strongly preferred randomly presented modulated sequences. These results suggest a neuronal substrate for an age-related increase in experience/attentional-based influences in processing temporally complex auditory information in the auditory thalamus.
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Over-expression of myosin7A in cochlear hair cells of circling mice. Lab Anim Res 2017; 33:1-7. [PMID: 28400833 PMCID: PMC5385277 DOI: 10.5625/lar.2017.33.1.1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 02/03/2017] [Accepted: 03/16/2017] [Indexed: 01/15/2023] Open
Abstract
Circling mouse (C57BL/6J-cir/cir) deleted the transmembrane inner ear (Tmie) gene is an animal model for human non-syndromic recessive deafness, DFNB6. In circling mouse, hair cells in the cochlea have degenerated and hair bundles have become irregularity as time goes on. Tmie protein carries out a function of the mechanoelectrical transduction channel in cochlear hair cells. Myosin7a (MYO7A) protein has key roles in development of the cochlear hair bundles as well as in the function of cochlear hair cells. To find whether Tmie protein interacts with MYO7A proteins in the cochlea postnatal developmental stage, we investigated expression of the MYO7A proteins in the cochlear hair cells of circling mice by western blot analysis and whole mount immunofluorescence at postnatal day 5 (P5). The expression of MYO7A showed statistically significant increase in the cochlea of C57BL/6J-+/cir and C57BL/6J-cir/cir mice than that of C57BL/6J-+/+ mice. The MYO7A intensity of the cochlear hair cells also increased in C57BL/6J-+/cir and C57BL/6J-cir/cir mice compared with those of C57BL/6J-+/+ mice. Taken together, the results indicate that Tmie protein may have an important role with MYO7A protein in the development and maintenance of the stereociliary bundles during postnatal developmental stage of the cochlea.
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Prakash Krishnan Muthaiah V, Ding D, Salvi R, Roth JA. Carbaryl-induced ototoxicity in rat postnatal cochlear organotypic cultures. ENVIRONMENTAL TOXICOLOGY 2017; 32:956-969. [PMID: 27296064 DOI: 10.1002/tox.22296] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Revised: 05/16/2016] [Accepted: 05/21/2016] [Indexed: 06/06/2023]
Abstract
Carbaryl, a widely used carbamate-based insecticide, is a potent anticholinesterase known to induce delayed neurotoxicity following chronic exposure. However, its potential toxic effects on the cochlea, the sensory organ for hearing that contains cholinergic efferent neurons and acetylcholine receptors on the hair cells (HC) and spiral ganglion neurons has heretofore not been evaluated. To assess ototoxic potential of carbaryl, cochlear organotypic cultures from postnatal day 3 rats were treated with doses of carbaryl ranging from 50 to 500 μM for 48 h up to 96 h. Carbaryl damaged both the sensory HC and spiral ganglion neurons in a dose- and duration-dependent manner. HC and neuronal damage was observed at carbaryl concentrations as low as 50 μM after 96-h treatment and 100 μM after 48-h treatment. Hair cell was greatest in the high frequency basal region of the cochlea and progressively decreased towards the apex consistent with the majority of ototoxic drugs. In contrast, damage to the spiral ganglion neurons was of similar magnitude in the basal and apical regions of the cochlea. Carbaryl damage was characterized by soma shrinkage, nuclear condensation and fragmentation, and blebbing, morphological features of programmed cell death. Carbaryl upregulated the expression of executioner caspase-3 in HC and spiral ganglion neurons indicating that cellular damage occurred primarily by caspase-mediated apoptosis. These results suggest that chronic exposure to carbaryl and other carbamate anticholinesterases may be ototoxic. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 956-969, 2017.
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Affiliation(s)
| | - Dalian Ding
- Center for Hearing and Deafness, University at Buffalo, Buffalo, New York, 14214
| | - Richard Salvi
- Center for Hearing and Deafness, University at Buffalo, Buffalo, New York, 14214
| | - Jerome A Roth
- Department of Pharmacology and Toxicology, University at Buffalo, Buffalo, New York, 14214
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Presacco A, Simon JZ, Anderson S. Effect of informational content of noise on speech representation in the aging midbrain and cortex. J Neurophysiol 2016; 116:2356-2367. [PMID: 27605531 PMCID: PMC5110638 DOI: 10.1152/jn.00373.2016] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Accepted: 09/07/2016] [Indexed: 11/22/2022] Open
Abstract
The ability to understand speech is significantly degraded by aging, particularly in noisy environments. One way that older adults cope with this hearing difficulty is through the use of contextual cues. Several behavioral studies have shown that older adults are better at following a conversation when the target speech signal has high contextual content or when the background distractor is not meaningful. Specifically, older adults gain significant benefit in focusing on and understanding speech if the background is spoken by a talker in a language that is not comprehensible to them (i.e., a foreign language). To understand better the neural mechanisms underlying this benefit in older adults, we investigated aging effects on midbrain and cortical encoding of speech when in the presence of a single competing talker speaking in a language that is meaningful or meaningless to the listener (i.e., English vs. Dutch). Our results suggest that neural processing is strongly affected by the informational content of noise. Specifically, older listeners' cortical responses to the attended speech signal are less deteriorated when the competing speech signal is an incomprehensible language rather than when it is their native language. Conversely, temporal processing in the midbrain is affected by different backgrounds only during rapid changes in speech and only in younger listeners. Additionally, we found that cognitive decline is associated with an increase in cortical envelope tracking, suggesting an age-related over (or inefficient) use of cognitive resources that may explain their difficulty in processing speech targets while trying to ignore interfering noise.
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Affiliation(s)
- Alessandro Presacco
- Department of Hearing and Speech Sciences, University of Maryland, College Park, Maryland;
- Neuroscience and Cognitive Science Program, University of Maryland, College Park, Maryland
| | - Jonathan Z Simon
- Neuroscience and Cognitive Science Program, University of Maryland, College Park, Maryland
- Department of Electrical and Computer Engineering, University of Maryland, College Park, Maryland
- Department of Biology, University of Maryland, College Park, Maryland; and
- Institute for Systems Research, University of Maryland, College Park, Maryland
| | - Samira Anderson
- Department of Hearing and Speech Sciences, University of Maryland, College Park, Maryland
- Neuroscience and Cognitive Science Program, University of Maryland, College Park, Maryland
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Abstract
OBJECTIVES The authors investigated aging effects on the envelope of the frequency following response to dynamic and static components of speech. Older adults frequently experience problems understanding speech, despite having clinically normal hearing. Improving audibility with hearing aids provides variable benefit, as amplification cannot restore the temporal precision degraded by aging. Previous studies have demonstrated age-related delays in subcortical timing specific to the dynamic, transition region of the stimulus. However, it is unknown whether this delay is mainly due to a failure to encode rapid changes in the formant transition because of central temporal processing deficits or as a result of cochlear damage that reduces audibility for the high-frequency components of the speech syllable. To investigate the nature of this delay, the authors compared subcortical responses in younger and older adults with normal hearing to the speech syllables /da/ and /a/, hypothesizing that the delays in peak timing observed in older adults are mainly caused by temporal processing deficits in the central auditory system. DESIGN The frequency following response was recorded to the speech syllables /da/ and /a/ from 15 younger and 15 older adults with normal hearing, normal IQ, and no history of neurological disorders. Both speech syllables were presented binaurally with alternating polarities at 80 dB SPL at a rate of 4.3 Hz through electromagnetically shielded insert earphones. A vertical montage of four Ag-AgCl electrodes (Cz, active, forehead ground, and earlobe references) was used. RESULTS The responses of older adults were significantly delayed with respect to younger adults for the transition and onset regions of the /da/ syllable and for the onset of the /a/ syllable. However, in contrast with the younger adults who had earlier latencies for /da/ than for /a/ (as was expected given the high-frequency energy in the /da/ stop consonant burst), latencies in older adults were not significantly different between the responses to /da/ and /a/. An unexpected finding was noted in the amplitude and phase dissimilarities between the two groups in the later part of the steady-state region, rather than in the transition region. This amplitude reduction may indicate prolonged neural recovery or response decay associated with a loss of auditory nerve fibers. CONCLUSIONS These results suggest that older adults' peak timing delays may arise from decreased synchronization to the onset of the stimulus due to reduced audibility, though the possible role of impaired central auditory processing cannot be ruled out. Conversely, a deterioration in temporal processing mechanisms in the auditory nerve, brainstem, or midbrain may be a factor in the sudden loss of synchronization in the later part of the steady-state response in older adults.
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Reijntjes DO, Pyott SJ. The afferent signaling complex: Regulation of type I spiral ganglion neuron responses in the auditory periphery. Hear Res 2016; 336:1-16. [DOI: 10.1016/j.heares.2016.03.011] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Revised: 02/12/2016] [Accepted: 03/07/2016] [Indexed: 12/19/2022]
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Dong Y, Guo CR, Ding Y, Zhang Y, Song HY, Peng YT, Zhang T, Shi JR. Effects of Erlong Zuoci decoction on the age-related hearing loss in C57BL/6J mice. JOURNAL OF ETHNOPHARMACOLOGY 2016; 181:59-65. [PMID: 26826327 DOI: 10.1016/j.jep.2016.01.025] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Revised: 10/12/2015] [Accepted: 01/18/2016] [Indexed: 06/05/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Erlong Zuoci decoction (ELZCD), a typical traditional Chinese medicine (TCM) prescription, has long been clinically used in treatment of deafness and tinnitus with the syndrome of "kidney yin deficiency". However, there are few studies to investigate its pharmacological mechanisms. Until now, there is not report about its effects on the age-related hearing loss (ARHL). AIM OF STUDY The present study was conducted to observe the effects of ELZCD on the ARHL in C57BL/6J mice and explore the mechanisms. MATERIALS AND METHODS ELZCD was fed to C57BL/6J mice from 3 months to 6 months in ELZCD group as a dose of 6g/kg/d. And the same volume of saline was fed to mice in ARHL group. 3-months-old C57BL/6J mice were used as control group. High performance liquid chromatography (HPLC) was used for the quality control of ELZCD. Auditory brainstem response (ABR) was used to assess the hearing function of mice. The morphologic changes were observed by hematoxylin eosin (HE) staining. Apoptosis was tested by terminal dexynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) method. Mitochondrial damage was detected by transmission electron microscopy (TEM). Quantitative RT-PCR (qRT-PCR) was used to observe the mRNA expression of p53 and Bak. Fluorescence immunohistochemical technique was used to test the protein expression of p53 and Bak. RESULTS The hearing threshold of ARHL group was higher than that of control group (P<0.001) and ELZCD decreased the rise of hearing threshold levels of ARHL mice (P<0.001), which suggested ELZCD inhibited the hearing loss of ARHL mice. HE staining showed that ELZCD decreased the spiral ganglion (SG) cell damage and loss in ARHL. TUNEL test showed that the apoptotic SG cells increased in ARHL group compared to control group and decreased in ELZCD group compared to ARHL group. TEM observation showed that mitochondrial damage was obvious in SG cells of ARHL group and ELZCD inhibited the mitochondrial damage. The qRT-PCR results showed that the mRNA expression of p53 and Bak in ARHL group increased compared to that of control group (P<0.05), and ELZCD reduced the elevated mRNA expression levels of p53 and Bak (P<0.01, P<0.05). In addition, ELZCD inhibited the increased proteins expression (green fluorescence) of p53 and Bak. CONCLUSION The results demonstrated that ELZCD prevented ARHL in C57BL/6J mice and p53/Bak-mediated mitochondrial apoptosis of SG cells might be involved in the mechanisms.
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Affiliation(s)
- Yang Dong
- Experimental Teaching Center, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Chun-Rong Guo
- Experimental Teaching Center, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Yue Ding
- Experimental Teaching Center, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Yong Zhang
- Experimental Teaching Center, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Hai-Yan Song
- Basic Medical College, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Yin-Ting Peng
- Experimental Teaching Center, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Tong Zhang
- Experimental Teaching Center, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Jian-Rong Shi
- Experimental Teaching Center, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China.
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Ruiz-Mendoza S, Macedo-Ramos H, Santos FA, Quadros-de-Souza LC, Paiva MM, Pinto TCA, Teixeira LM, Baetas-da-Cruz W. Streptococcus pneumoniae infection regulates expression of neurotrophic factors in the olfactory bulb and cultured olfactory ensheathing cells. Neuroscience 2016; 317:149-61. [PMID: 26791522 DOI: 10.1016/j.neuroscience.2016.01.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Revised: 12/31/2015] [Accepted: 01/05/2016] [Indexed: 12/22/2022]
Abstract
Streptococcus pneumoniae is the causative agent of numerous diseases including severe invasive infections such as bacteremia and meningitis. It has been previously shown that strains of S. pneumoniae that are unable to survive in the bloodstream may colonize the CNS. However, information on cellular components and pathways involved in the neurotropism of these strains is still scarce. The olfactory system is a specialized tissue in which olfactory receptor neurons (ORNs) are interfacing with the external environment through several microvilli. Olfactory ensheathing cells (OECs) which also form the glial limiting membrane at the surface of the olfactory bulb (OB) are the only cells that ensheathe the ORNs axons. Since previous data from our group showed that OECs may harbor S. pneumoniae, we decided to test whether infection of the OB or OEC cultures modulates the expression levels of neurotrophic factor's mRNA and its putative effects on the activation and viability of microglia. We observed that neurotrophin-3 (NT-3) and glial cell-line-derived neurotrophic factor (GDNF) expression was significantly higher in the OB from uninfected mice than in infected mice. A similar result was observed when we infected OEC cultures. Brain-derived neurotrophic factor (BNDF) expression was significantly lower in the OB from infected mice than in uninfected mice. In contrast, in vitro infection of OECs resulted in a significant increase of BDNF mRNA expression. An upregulation of high-mobility group box 1 (HMGB1) expression was observed in both OB and OEC cultures infected with S. pneumoniae. Moreover, we found that conditioned medium from infected OEC cultures induced the expression of the pro-apoptotic protein cleaved-caspase-3 and an apparently continuous nuclear factor-kappa B (NF-κB) p65 activation in the N13 microglia. Altogether, our data suggest the possible existence of an OEC-pathogen molecular interface, through which the OECs could interfere on the activation and viability of microglia, favoring the access of non-hematogenous S. pneumoniae strains to the CNS in the absence of bacteremia.
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Affiliation(s)
- S Ruiz-Mendoza
- Laboratório Translacional em Fisiologia Molecular, Centro de Cirurgia Experimental, Faculdade de Medicina, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil; Instituto de Biofísica Carlos Chagas Filho, Programa de Pós-Graduação em Ciências Biológicas (Fisiologia), Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - H Macedo-Ramos
- Laboratório Translacional em Fisiologia Molecular, Centro de Cirurgia Experimental, Faculdade de Medicina, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil; Instituto de Biofísica Carlos Chagas Filho, Programa de Pós-Graduação em Ciências Biológicas (Fisiologia), Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - F A Santos
- Laboratório Translacional em Fisiologia Molecular, Centro de Cirurgia Experimental, Faculdade de Medicina, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - L C Quadros-de-Souza
- Laboratório Translacional em Fisiologia Molecular, Centro de Cirurgia Experimental, Faculdade de Medicina, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - M M Paiva
- Instituto Nacional de Tecnologia, Rio de Janeiro, RJ, Brazil
| | - T C A Pinto
- Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - L M Teixeira
- Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - W Baetas-da-Cruz
- Laboratório Translacional em Fisiologia Molecular, Centro de Cirurgia Experimental, Faculdade de Medicina, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil; Instituto de Biofísica Carlos Chagas Filho, Programa de Pós-Graduação em Ciências Biológicas (Fisiologia), Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
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Stevens SM, Brown LN, Ezell PC, Lang H. The Mouse Round-window Approach for Ototoxic Agent Delivery: A Rapid and Reliable Technique for Inducing Cochlear Cell Degeneration. J Vis Exp 2015. [PMID: 26650771 DOI: 10.3791/53131] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Investigators have utilized a wide array of animal models and investigative techniques to study the mammalian auditory system. Much of the basic research involving the cochlea and its associated neural pathways entails exposure of model cochleae to a variety of ototoxic agents. This allows investigators to study the effects of targeted damage to cochlear structures, and in some cases, the self-repair or regeneration of those structures. Various techniques exist for delivery of ototoxic agents to the cochlea. When selecting a particular technique, investigators must consider a number of factors, including the induction of inadvertent systemic toxicity, the amount of cochlear damage produced by the surgical procedure itself, the type of lesion desired, animal survivability, and reproducibility/reliability of results. Currently established techniques include parenteral injection, intra-peritoneal injection, trans-tympanic injection, endolymphatic sac injection, and cochleostomy with perilymphatic perfusion. Each of these methods has been successfully utilized and is well described in the literature; yet, each has various shortcomings. Here, we present a technique for topical application of ototoxic agents directly to the round window niche. This technique is non-invasive to inner ear structures, produces rapid onset of reliably targeted lesions, avoids systemic toxicity, and allows for an intra-animal control (the contra-lateral ear). Results stemming from this approach have helped deeper understanding of auditory pathophysiology, cochlear cell degeneration, and regenerative capacity in response to an acute injury. Future investigations may use this method to conduct interventional studies involving gene therapy and stem cell transplantation to combat hearing loss.
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Affiliation(s)
- Shawn M Stevens
- Department of Otolaryngology Head and Neck Surgery, Medical University of South Carolina
| | - LaShardai N Brown
- Department of Pathology and Laboratory Sciences, Medical University of South Carolina
| | | | - Hainan Lang
- Department of Pathology and Laboratory Sciences, Medical University of South Carolina;
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Sanchez J, Ghelani S, Otto-Meyer S. From development to disease: Diverse functions of NMDA-type glutamate receptors in the lower auditory pathway. Neuroscience 2015; 285:248-59. [DOI: 10.1016/j.neuroscience.2014.11.027] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Revised: 11/07/2014] [Accepted: 11/16/2014] [Indexed: 01/19/2023]
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Horvath L, Bodmer D, Radojevic V, Monge Naldi A. Activin Signaling Disruption in the Cochlea Does Not Influence Hearing in Adult Mice. Audiol Neurootol 2014; 20:51-61. [DOI: 10.1159/000366152] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Accepted: 07/24/2014] [Indexed: 11/19/2022] Open
Abstract
Activin, a member of the TGF-F superfamily, was found to play an important role in the development, repair and apoptosis of different tissues and organs. Accordingly, activin signaling is involved in the development of the cochlea. Activin binds to its receptor ActRII, then dimerizes with ActRI and induces a signaling pathway resulting in gene expression. A study reported a case of fibrodysplasia ossificans progressiva with an unusual mutation in the ActRI gene leading to sensorineural hearing loss. This draws attention to the role of activin and its receptors in the developed cochlea. To date, only the expression of ActRII is known in the adult mammalian cochlea. In this study, we present for the first time the presence of activin A and ActRIB in the adult cochlea. Transgenic mice with postnatal dominant-negative ActRIB expression causing disruption of activin signaling in vivo were used for assessing cochlear morphology and hearing ability through the auditory brainstem response (ABR) threshold. Nonfunctioning ActRIB did not affect the ABR thresholds and did not alter the microscopic anatomy of the cochlea. We conclude, therefore, that activin signaling is not necessary for hearing in adult mice under physiological conditions but may be important during and after damaging events in the inner ear. i 2014 S. Karger AG, Basel
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Gao F, Wang G, Ma W, Ren F, Li M, Dong Y, Liu C, Liu B, Bai X, Zhao B, Edden RAE. Decreased auditory GABA+ concentrations in presbycusis demonstrated by edited magnetic resonance spectroscopy. Neuroimage 2014; 106:311-6. [PMID: 25463460 DOI: 10.1016/j.neuroimage.2014.11.023] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Revised: 10/02/2014] [Accepted: 11/11/2014] [Indexed: 12/14/2022] Open
Abstract
Gamma-aminobutyric acid (GABA) is the main inhibitory neurotransmitter in the central auditory system. Altered GABAergic neurotransmission has been found in both the inferior colliculus and the auditory cortex in animal models of presbycusis. Edited magnetic resonance spectroscopy (MRS), using the MEGA-PRESS sequence, is the most widely used technique for detecting GABA in the human brain. However, to date there has been a paucity of studies exploring changes to the GABA concentrations in the auditory region of patients with presbycusis. In this study, sixteen patients with presbycusis (5 males/11 females, mean age 63.1 ± 2.6 years) and twenty healthy controls (6 males/14 females, mean age 62.5 ± 2.3 years) underwent audiological and MRS examinations. Pure tone audiometry from 0.125 to 8 kHz and tympanometry were used to assess the hearing abilities of all subjects. The pure tone average (PTA; the average of hearing thresholds at 0.5, 1, 2 and 4 kHz) was calculated. The MEGA-PRESS sequence was used to measure GABA+ concentrations in 4 × 3 × 3 cm(3) volumes centered on the left and right Heschl's gyri. GABA+ concentrations were significantly lower in the presbycusis group compared to the control group (left auditory regions: p = 0.002, right auditory regions: p = 0.008). Significant negative correlations were observed between PTA and GABA+ concentrations in the presbycusis group (r = -0.57, p = 0.02), while a similar trend was found in the control group (r = -0.40, p = 0.08). These results are consistent with a hypothesis of dysfunctional GABAergic neurotransmission in the central auditory system in presbycusis and suggest a potential treatment target for presbycusis.
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Affiliation(s)
- Fei Gao
- Shandong Medical Imaging Research Institute, Shandong University, Jinan, China
| | - Guangbin Wang
- Shandong Medical Imaging Research Institute, Shandong University, Jinan, China
| | - Wen Ma
- The Central Hospital of Jinan City, Shandong University, Jinan, China
| | - Fuxin Ren
- Shandong Medical Imaging Research Institute, Shandong University, Jinan, China
| | - Muwei Li
- College of Electronics and Information Engineering, Sichuan University, Chengdu, China
| | - Yuling Dong
- The Central Hospital of Jinan City, Shandong University, Jinan, China
| | - Cheng Liu
- Shandong Medical Imaging Research Institute, Shandong University, Jinan, China
| | - Bo Liu
- Shandong Medical Imaging Research Institute, Shandong University, Jinan, China
| | - Xue Bai
- Shandong Medical Imaging Research Institute, Shandong University, Jinan, China
| | - Bin Zhao
- Shandong Medical Imaging Research Institute, Shandong University, Jinan, China.
| | - Richard A E Edden
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, USA; FM Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA
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Kariya S, Okano M, Maeda Y, Hirai H, Higaki T, Noyama Y, Haruna T, Nishihira J, Nishizaki K. Role of macrophage migration inhibitory factor in age-related hearing loss. Neuroscience 2014; 279:132-8. [DOI: 10.1016/j.neuroscience.2014.08.042] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Revised: 08/23/2014] [Accepted: 08/26/2014] [Indexed: 01/29/2023]
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