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Postolache M, Connelly Graham CJ, Burke K, Lauer AM, Xu-Friedman MA. Effects of Age on Responses of Principal Cells of the Mouse Anteroventral Cochlear Nucleus in Quiet and Noise. eNeuro 2024; 11:ENEURO.0215-24.2024. [PMID: 39134409 DOI: 10.1523/eneuro.0215-24.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2024] [Accepted: 06/24/2024] [Indexed: 08/15/2024] Open
Abstract
Older listeners often report difficulties understanding speech in noisy environments. It is important to identify where in the auditory pathway hearing-in-noise deficits arise to develop appropriate therapies. We tested how encoding of sounds is affected by masking noise at early stages of the auditory pathway by recording responses of principal cells in the anteroventral cochlear nucleus (AVCN) of aging CBA/CaJ and C57BL/6J mice in vivo. Previous work indicated that masking noise shifts the dynamic range of single auditory nerve fibers (ANFs), leading to elevated tone thresholds. We hypothesized that such threshold shifts could contribute to increased hearing-in-noise deficits with age if susceptibility to masking increased in AVCN units. We tested this by recording the responses of AVCN principal neurons to tones in the presence and absence of masking noise. Surprisingly, we found that masker-induced threshold shifts decreased with age in primary-like units and did not change in choppers. In addition, spontaneous activity decreased in primary-like and chopper units of old mice, with no change in dynamic range or tuning precision. In C57 mice, which undergo early-onset hearing loss, units showed similar changes in threshold and spontaneous rate at younger ages, suggesting they were related to hearing loss and not simply aging. These findings suggest that sound information carried by AVCN principal cells remains largely unchanged with age. Therefore, hearing-in-noise deficits may result from other changes during aging, such as distorted across-channel input from the cochlea and changes in sound coding at later stages of the auditory pathway.
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Affiliation(s)
- Maggie Postolache
- Department of Biological Sciences, University at Buffalo, State University of NewYork, Buffalo, New York 14260
| | - Catherine J Connelly Graham
- Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Kali Burke
- Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Amanda M Lauer
- Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
- Solomon H. Snyder Dept. of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Matthew A Xu-Friedman
- Department of Biological Sciences, University at Buffalo, State University of NewYork, Buffalo, New York 14260
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2
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Alashram AR. The efficacy of transcranial random noise stimulation in treating tinnitus: a systematic review. Eur Arch Otorhinolaryngol 2024:10.1007/s00405-024-08858-9. [PMID: 39046497 DOI: 10.1007/s00405-024-08858-9] [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: 06/29/2024] [Accepted: 07/17/2024] [Indexed: 07/25/2024]
Abstract
PURPOSE This review aims to examine the effects of transcranial random noise stimulation (tRNS) on tinnitus and to determine the optimal treatment parameters, if possible. METHODS A comprehensive search, including MEDLINE, PubMed, EMBASE, CINAHL, SCOPUS, and PEDro, was conducted to determine experiments studying the effects of tRNS on tinnitus from inception to March 1, 2024. The Physiotherapy Evidence Database (PEDro) scale was used to evaluate the quality of the included studies. RESULTS Seven studies met the eligibility criteria. A total of 616 patients with non-pulsatile tinnitus (mean age 50.93 years; 66% males) were included in this review. The included studies ranged from 3 to 8 out of 10 (median = 7) on the PEDro scale. The results showed that tRNS is an effective intervention in reducing tinnitus symptoms. CONCLUSIONS The evidence for the effects of tRNS on people with chronic non-pulsatile tinnitus is promising. Administering tRNS with an intensity of 1-2 mA, high-frequency (101-650 Hz), using a 35 cm² electrode size over the auditory cortex and DLPFC, for 20 min with eight sessions may demonstrate the desired tRNS effects. The tRNS stimulation should be contralateral for unilateral tinnitus and bilaterally for bilateral tinnitus. Combining tRNS with other concurrent interventions may show superior effects in reducing tinnitus compared to tRNS alone. Further high-quality studies with larger sample sizes are strongly needed.
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Affiliation(s)
- Anas R Alashram
- Department of Physiotherapy, Middle East University, Airport Road, Amman, 1666, Jordan.
- Applied Science Research Center, Applied Science Private University, Amman, Jordan.
- Centre of SpaceBio-Medicine, Department of Systems Medicine, Faculty of Medicine and Surgery, San Raffaele Roma Open University, University of Rome "Tor Vergata", Rome, 00133, Italy.
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Sendesen E, Colak H. Neural markers associated with improved tinnitus perception after tinnitus retraining therapy. Int J Audiol 2024:1-7. [PMID: 39037049 DOI: 10.1080/14992027.2024.2378800] [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: 12/17/2023] [Accepted: 06/27/2024] [Indexed: 07/23/2024]
Abstract
OBJECTIVE Tinnitus retraining therapy (TRT) has been widely used in tinnitus management. However, its efficacy is often assessed through subjective methods. Here, we aimed to assess potential neural changes following TRT using mismatch negativity (MMN). DESIGN Chronic tinnitus (>6 months) patients participated in a six-month TRT program. We collected tinnitus psychoacoustic features and gathered the tinnitus handicap inventory (THI) before and after TRT. We also used a multi-featured paradigm, including frequency, intensity, duration, location and silent gap deviants, to elicit MMN response before and after TRT. Data were analyzed retrospectively. STUDY SAMPLE The study involved 26 chronic tinnitus patients. RESULTS Post-TRT measurements showed that MMN amplitudes significantly increased for all deviant conditions (p ≤ .03). However, we did not find a significant difference in MMN latencies for all deviant conditions (p ≥ .13). The THI scores of the patients significantly decreased following the TRT program (p < 0.001). Our results reveal improved subjective tinnitus perception following the TRT program. CONCLUSION These findings indicate that TRT might be a viable alternative in tinnitus management. The greater MMN amplitudes and improved subjective tinnitus perception raise the possibility that MMN can be a useful tool in tinnitus research and tinnitus patient follow-up.
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Affiliation(s)
- Eser Sendesen
- Department of Audiology, Hacettepe University, Ankara, Turkey
| | - Hasan Colak
- Biosciences Institute, Newcastle University, Newcastle upon Tyne, UK
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Gross J, Knipper M, Mazurek B. Candidate Key Proteins in Tinnitus-A Bioinformatic Study of Synaptic Transmission in the Cochlear Nucleus. Biomedicines 2024; 12:1615. [PMID: 39062188 PMCID: PMC11274367 DOI: 10.3390/biomedicines12071615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2024] [Revised: 07/11/2024] [Accepted: 07/12/2024] [Indexed: 07/28/2024] Open
Abstract
The aim of this study was to identify key proteins of synaptic transmission in the cochlear nucleus (CN) that are involved in normal hearing, acoustic stimulation, and tinnitus. A gene list was compiled from the GeneCards database using the keywords "synaptic transmission" AND "tinnitus" AND "cochlear nucleus" (Tin). For comparison, two gene lists with the keywords "auditory perception" (AP) AND "acoustic stimulation" (AcouStim) were built. The STRING protein-protein interaction (PPI) network and the Cytoscape data analyzer were used to identify the top two high-degree proteins (HDPs) and their high-score interaction proteins (HSIPs), together referred to as key proteins. The top1 key proteins of the Tin-process were BDNF, NTRK1, NTRK3, and NTF3; the top2 key proteins are FOS, JUN, CREB1, EGR1, MAPK1, and MAPK3. Highly significant GO terms in CN in tinnitus were "RNA polymerase II transcription factor complex", "late endosome", cellular response to cadmium ion", "cellular response to reactive oxygen species", and "nerve growth factor signaling pathway", indicating changes in vesicle and cell homeostasis. In contrast to the spiral ganglion, where important changes in tinnitus are characterized by processes at the level of cells, important biological changes in the CN take place at the level of synapses and transcription.
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Affiliation(s)
- Johann Gross
- Tinnitus Center, Charité-Universitätsmedizin Berlin, 10117 Berlin, Germany;
- Leibniz Society of Science Berlin, 10117 Berlin, Germany;
| | - Marlies Knipper
- Leibniz Society of Science Berlin, 10117 Berlin, Germany;
- Department of Otolaryngology, Head and Neck Surgery, Tübingen Hearing Research Center (THRC), Molecular Physiology of Hearing, University of Tübingen, 72076 Tübingen, Germany
| | - Birgit Mazurek
- Tinnitus Center, Charité-Universitätsmedizin Berlin, 10117 Berlin, Germany;
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Poe AA, Karawani H, Anderson S. Aging effects on the neural representation and perception of consonant transition cues. Hear Res 2024; 448:109034. [PMID: 38781768 PMCID: PMC11156531 DOI: 10.1016/j.heares.2024.109034] [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: 01/11/2024] [Revised: 04/16/2024] [Accepted: 05/13/2024] [Indexed: 05/25/2024]
Abstract
Older listeners have difficulty processing temporal cues that are important for word discrimination, and deficient processing may limit their ability to benefit from these cues. Here, we investigated aging effects on perception and neural representation of the consonant transition and the factors that contribute to successful perception. To further understand the neural mechanisms underlying the changes in processing from brainstem to cortex, we also examined the factors that contribute to exaggerated amplitudes in cortex. We enrolled 30 younger normal-hearing and 30 older normal-hearing participants who met the criteria of clinically normal hearing. Perceptual identification functions were obtained for the words BEAT and WHEAT on a 7-step continuum of consonant-transition duration. Auditory brainstem responses (ABRs) were recorded to click stimuli and frequency-following responses (FFRs) and cortical auditory-evoked potentials were recorded to the endpoints of the BEAT-WHEAT continuum. Perceptual performance for identification of BEAT vs. WHEAT did not differ between younger and older listeners. However, both subcortical and cortical measures of neural representation showed age group differences, such that FFR phase locking was lower but cortical amplitudes (P1 and N1) were higher in older compared to younger listeners. ABR Wave I amplitude and FFR phase locking, but not audiometric thresholds, predicted early cortical amplitudes. Phase locking to the transition region and early cortical peak amplitudes (P1) predicted performance on the perceptual identification function. Overall, results suggest that the neural representation of transition durations and cortical overcompensation may contribute to the ability to perceive transition duration contrasts. Cortical overcompensation appears to be a maladaptive response to decreased neural firing/synchrony.
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Affiliation(s)
- Abigail Anne Poe
- Department of Hearing and Speech Sciences, University of Maryland, College Park, MD, USA
| | - Hanin Karawani
- Department of Communication Sciences and Disorders, Faculty of Social Welfare and Health Sciences, University of Haifa, Haifa, Israel
| | - Samira Anderson
- Department of Hearing and Speech Sciences, University of Maryland, College Park, MD, USA; Neuroscience and Cognitive Science Program, University of Maryland, College Park, Maryland, USA.
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6
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Bartlett EL, Han EX, Parthasarathy A. Neurometric amplitude modulation detection in the inferior colliculus of Young and Aged rats. Hear Res 2024; 447:109028. [PMID: 38733711 PMCID: PMC11129790 DOI: 10.1016/j.heares.2024.109028] [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: 01/23/2024] [Revised: 04/29/2024] [Accepted: 05/02/2024] [Indexed: 05/13/2024]
Abstract
Amplitude modulation is an important acoustic cue for sound discrimination, and humans and animals are able to detect small modulation depths behaviorally. In the inferior colliculus (IC), both firing rate and phase-locking may be used to detect amplitude modulation. How neural representations that detect modulation change with age are poorly understood, including the extent to which age-related changes may be attributed to the inherited properties of ascending inputs to IC neurons. Here, simultaneous measures of local field potentials (LFPs) and single-unit responses were made from the inferior colliculus of Young and Aged rats using both noise and tone carriers in response to sinusoidally amplitude-modulated sounds of varying depths. We found that Young units had higher firing rates than Aged for noise carriers, whereas Aged units had higher phase-locking (vector strength), especially for tone carriers. Sustained LFPs were larger in Young animals for modulation frequencies 8-16 Hz and comparable at higher modulation frequencies. Onset LFP amplitudes were much larger in Young animals and were correlated with the evoked firing rates, while LFP onset latencies were shorter in Aged animals. Unit neurometric thresholds by synchrony or firing rate measures did not differ significantly across age and were comparable to behavioral thresholds in previous studies whereas LFP thresholds were lower than behavior.
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Affiliation(s)
- Edward L Bartlett
- Department of Biological Sciences and the Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN 47907, United States; Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907, United States.
| | - Emily X Han
- Department of Biological Sciences and the Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN 47907, United States
| | - Aravindakshan Parthasarathy
- Department of Biological Sciences and the Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN 47907, United States
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Parameshwarappa V, Siponen MI, Watabe I, Karkaba A, Galazyuk A, Noreña AJ. Noise-induced hearing loss alters potassium-chloride cotransporter KCC2 and GABA inhibition in the auditory centers. Sci Rep 2024; 14:10689. [PMID: 38724641 PMCID: PMC11082187 DOI: 10.1038/s41598-024-60858-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Accepted: 04/29/2024] [Indexed: 05/12/2024] Open
Abstract
Homeostatic plasticity, the ability of neurons to maintain their averaged activity constant around a set point value, is thought to account for the central hyperactivity after hearing loss. Here, we investigated the putative role of GABAergic neurotransmission in this mechanism after a noise-induced hearing loss larger than 50 dB in high frequencies in guinea pigs. The effect of GABAergic inhibition is linked to the normal functioning of K + -Cl- co-transporter isoform 2 (KCC2) which maintains a low intracellular concentration of chloride. The expression of membrane KCC2 were investigated before and after noise trauma in the ventral and dorsal cochlear nucleus (VCN and DCN, respectively) and in the inferior colliculus (IC). Moreover, the effect of gabazine (GBZ), a GABA antagonist, was also studied on the neural activity in IC. We show that KCC2 is downregulated in VCN, DCN and IC 3 days after noise trauma, and in DCN and IC 30 days after the trauma. As expected, GBZ application in the IC of control animals resulted in an increase of spontaneous and stimulus-evoked activity. In the noise exposed animals, on the other hand, GBZ application decreased the stimulus-evoked activity in IC neurons. The functional implications of these central changes are discussed.
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Affiliation(s)
- V Parameshwarappa
- Laboratory of Cognitive Neurosciences, Centre National de la Recherche Scientifique, Aix-Marseille University, 3 Place Victor Hugo, 13003, Marseille, France
| | - M I Siponen
- Laboratory of Cognitive Neurosciences, Centre National de la Recherche Scientifique, Aix-Marseille University, 3 Place Victor Hugo, 13003, Marseille, France
| | - I Watabe
- Laboratory of Cognitive Neurosciences, Centre National de la Recherche Scientifique, Aix-Marseille University, 3 Place Victor Hugo, 13003, Marseille, France
| | - A Karkaba
- Laboratory of Cognitive Neurosciences, Centre National de la Recherche Scientifique, Aix-Marseille University, 3 Place Victor Hugo, 13003, Marseille, France
| | - A Galazyuk
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, OH, USA
| | - A J Noreña
- Laboratory of Cognitive Neurosciences, Centre National de la Recherche Scientifique, Aix-Marseille University, 3 Place Victor Hugo, 13003, Marseille, France.
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Mellott JG, Duncan S, Busby J, Almassri LS, Wawrzyniak A, Iafrate MC, Ohl AP, Slabinski EA, Beaver AM, Albaba D, Vega B, Mafi AM, Buerke M, Tokar NJ, Young JW. Age-related upregulation of dense core vesicles in the central inferior colliculus. Front Cell Neurosci 2024; 18:1396387. [PMID: 38774486 PMCID: PMC11107844 DOI: 10.3389/fncel.2024.1396387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Accepted: 04/11/2024] [Indexed: 05/24/2024] Open
Abstract
Presbycusis is one of the most prevalent disabilities in aged populations of industrialized countries. As we age less excitation reaches the central auditory system from the periphery. To compensate, the central auditory system [e.g., the inferior colliculus (IC)], downregulates GABAergic inhibition to maintain homeostatic balance. However, the continued downregulation of GABA in the IC causes a disruption in temporal precision related to presbycusis. Many studies of age-related changes to neurotransmission in the IC have therefore focused on GABAergic systems. However, we have discovered that dense core vesicles (DCVs) are significantly upregulated with age in the IC. DCVs can carry neuropeptides, co-transmitters, neurotrophic factors, and proteins destined for the presynaptic zone to participate in synaptogenesis. We used immuno transmission electron microscopy across four age groups (3-month; 19-month; 24-month; and 28-month) of Fisher Brown Norway rats to examine the ultrastructure of DCVs in the IC. Tissue was stained post-embedding for GABA immunoreactivity. DCVs were characterized by diameter and by the neurochemical profile (GABAergic/non-GABAergic) of their location (bouton, axon, soma, and dendrite). Our data was collected across the dorsolateral to ventromedial axis of the central IC. After quantification, we had three primary findings. First, the age-related increase of DCVs occurred most robustly in non-GABAergic dendrites in the middle and low frequency regions of the central IC during middle age. Second, the likelihood of a bouton having more than one DCV increased with age. Lastly, although there was an age-related loss of terminals throughout the IC, the proportion of terminals that contained at least one DCV did not decline. We interpret this finding to mean that terminals carrying proteins packaged in DCVs are spared with age. Several recent studies have demonstrated a role for neuropeptides in the IC in defining cell types and regulating inhibitory and excitatory neurotransmission. Given the age-related increase of DCVs in the IC, it will be critical that future studies determine whether (1) specific neuropeptides are altered with age in the IC and (2) if these neuropeptides contribute to the loss of inhibition and/or increase of excitability that occurs during presbycusis and tinnitus.
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Affiliation(s)
- Jeffrey G. Mellott
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, OH, United States
- University Hospitals Hearing Research Center, Northeast Ohio Medical University, Rootstown, OH, United States
| | - Syllissa Duncan
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, OH, United States
| | - Justine Busby
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, OH, United States
| | - Laila S. Almassri
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, OH, United States
- University Hospitals Hearing Research Center, Northeast Ohio Medical University, Rootstown, OH, United States
| | - Alexa Wawrzyniak
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, OH, United States
| | - Milena C. Iafrate
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, OH, United States
| | - Andrew P. Ohl
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, OH, United States
| | - Elizabeth A. Slabinski
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, OH, United States
| | - Abigail M. Beaver
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, OH, United States
| | - Diana Albaba
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, OH, United States
| | - Brenda Vega
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, OH, United States
| | - Amir M. Mafi
- The Ohio State University College of Medicine, Columbus, OH, United States
| | - Morgan Buerke
- Department of Psychology, Louisiana State University, Baton Rouge, LA, United States
| | - Nick J. Tokar
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, OH, United States
| | - Jesse W. Young
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, OH, United States
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9
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Castaño-González K, Köppl C, Pyott SJ. The crucial role of diverse animal models to investigate cochlear aging and hearing loss. Hear Res 2024; 445:108989. [PMID: 38518394 DOI: 10.1016/j.heares.2024.108989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Revised: 02/18/2024] [Accepted: 03/04/2024] [Indexed: 03/24/2024]
Abstract
Age-related hearing loss affects a large and growing segment of the population, with profound impacts on quality of life. Age-related pathology of the cochlea-the mammalian hearing organ-underlies age-related hearing loss. Because investigating age-related changes in the cochlea in humans is challenging and often impossible, animal models are indispensable to investigate these mechanisms as well as the complex consequences of age-related hearing loss on the brain and behavior. In this review, we advocate for a comparative and interdisciplinary approach while also addressing the challenges of comparing age-related hearing loss across species with varying lifespans. We describe the experimental advantages and limitations as well as areas for future research in well-established models of age-related hearing loss, including mice, rats, gerbils, chinchillas, and birds. We also indicate the need to expand characterization of age-related hearing loss in other established animal models, especially guinea pigs, cats, and non-human primates, in which auditory function is well characterized but age-related cochlear pathology is understudied. Finally, we highlight the potential of emerging animal models for advancing our understanding of age-related hearing loss, including deer mice, with their notably extended lifespans and preserved hearing, naked mole rats, with their exceptional longevity and extensive vocal communications, as well as zebrafish, which offer genetic tractability and suitability for drug screening. Ultimately, a comparative and interdisciplinary approach in auditory research, combining insights from various animal models with human studies, is key to robust and reliable research outcomes that better advance our understanding and treatment of age-related hearing loss.
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Affiliation(s)
- Karen Castaño-González
- Department of Otorhinolaryngology, Head & Neck Surgery, University Medical Center Groningen; The Research School of Behavioural and Cognitive Neurosciences, University of Groningen, Groningen, The Netherlands
| | - Christine Köppl
- Cluster of Excellence "Hearing4All", Department of Neuroscience, School of Medicine and Health Sciences, Carl von Ossietzky Universität; Research Center Neurosensory Science, Carl von Ossietzky Universität, Oldenburg, Germany
| | - Sonja J Pyott
- Department of Otorhinolaryngology, Head & Neck Surgery, University Medical Center Groningen; The Research School of Behavioural and Cognitive Neurosciences, University of Groningen, Groningen, The Netherlands.
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Mittelstadt JK, Shilling-Scrivo KV, Kanold PO. Long-term training alters response dynamics in the aging auditory cortex. Hear Res 2024; 444:108965. [PMID: 38364511 PMCID: PMC11186583 DOI: 10.1016/j.heares.2024.108965] [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: 11/27/2023] [Revised: 01/16/2024] [Accepted: 01/20/2024] [Indexed: 02/18/2024]
Abstract
Age-related auditory dysfunction, presbycusis, is caused in part by functional changes in the auditory cortex (ACtx) such as altered response dynamics and increased population correlations. Given the ability of cortical function to be altered by training, we tested if performing auditory tasks might benefit auditory function in old age. We examined this by training adult mice on a low-effort tone-detection task for at least six months and then investigated functional responses in ACtx at an older age (∼18 months). Task performance remained stable well into old age. Comparing sound-evoked responses of thousands of ACtx neurons using in vivo 2-photon Ca2+ imaging, we found that many aspects of youthful neuronal activity, including low activity correlations, lower neural excitability, and a greater proportion of suppressed responses, were preserved in trained old animals as compared to passively-exposed old animals. Thus, consistent training on a low-effort task can benefit age-related functional changes in ACtx and may preserve many aspects of auditory function.
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Affiliation(s)
- Jonah K Mittelstadt
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21205, USA; Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD 21205, USA; Department of Biology, University of Maryland, College Park, MD 20742, USA
| | - Kelson V Shilling-Scrivo
- Department of Biology, University of Maryland, College Park, MD 20742, USA; Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21230, USA
| | - Patrick O Kanold
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21205, USA; Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD 21205, USA; Department of Biology, University of Maryland, College Park, MD 20742, USA; Kavli Neuroscience Discovery Institute, Johns Hopkins University, Baltimore, MD 21205, USA.
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11
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Fernández Del Campo IS, Carmona-Barrón VG, Diaz I, Plaza I, Alvarado JC, Merchán MA. Multisession anodal epidural direct current stimulation of the auditory cortex delays the progression of presbycusis in the Wistar rat. Hear Res 2024; 444:108969. [PMID: 38350175 DOI: 10.1016/j.heares.2024.108969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Revised: 01/23/2024] [Accepted: 02/02/2024] [Indexed: 02/15/2024]
Abstract
Presbycusis or age-related hearing loss (ARHL) is one of the most prevalent chronic health problems facing aging populations. Along the auditory pathway, the stations involved in transmission and processing, function as a system of interconnected feedback loops. Regulating hierarchically auditory processing, auditory cortex (AC) neuromodulation can, accordingly, activate both peripheral and central plasticity after hearing loss. However, previous ARHL-prevention interventions have mainly focused on preserving the structural and functional integrity of the inner ear, overlooking the central auditory system. In this study, using an animal model of spontaneous ARHL, we aim at assessing the effects of multisession epidural direct current stimulation of the AC through stereotaxic implantation of a 1-mm silver ball anode in Wistar rats. Consisting of 7 sessions (0.1 mA/10 min), on alternate days, in awake animals, our stimulation protocol was applied at the onset of hearing loss (threshold shift detection at 16 months). Click- and pure-tone auditory brainstem responses (ABRs) were analyzed in two animal groups, namely electrically stimulated (ES) and non-stimulated (NES) sham controls, comparing recordings at 18 months of age. At 18 months, NES animals showed significantly increased threshold shifts, decreased wave amplitudes, and increased wave latencies after click and tonal ABRs, reflecting a significant, spontaneous ARHL evolution. Conversely, in ES animals, no significant differences were detected in any of these parameters when comparing 16 and 18 months ABRs, indicating a delay in ARHL progression. Electrode placement in the auditory cortex was accurate, and the stimulation did not cause significant damage, as shown by the limited presence of superficial reactive microglial cells after IBA1 immunostaining. In conclusion, multisession DC stimulation of the AC has a protective effect on auditory function, delaying the progression of presbycusis.
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Affiliation(s)
- Inés S Fernández Del Campo
- Lab.4 Auditory Neuroplasticity, Institute for Neuroscience of Castilla y León. University of Salamanca. Salamanca, Spain
| | - Venezia G Carmona-Barrón
- Lab.4 Auditory Neuroplasticity, Institute for Neuroscience of Castilla y León. University of Salamanca. Salamanca, Spain
| | - I Diaz
- Lab.4 Auditory Neuroplasticity, Institute for Neuroscience of Castilla y León. University of Salamanca. Salamanca, Spain
| | - I Plaza
- Lab.4 Auditory Neuroplasticity, Institute for Neuroscience of Castilla y León. University of Salamanca. Salamanca, Spain
| | - J C Alvarado
- Facultad de Medicina, IDINE, Universidad de Castilla la Mancha, Albacete, Spain
| | - M A Merchán
- Lab.4 Auditory Neuroplasticity, Institute for Neuroscience of Castilla y León. University of Salamanca. Salamanca, Spain.
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12
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Panela RA, Copelli F, Herrmann B. Reliability and generalizability of neural speech tracking in younger and older adults. Neurobiol Aging 2024; 134:165-180. [PMID: 38103477 DOI: 10.1016/j.neurobiolaging.2023.11.007] [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: 07/27/2023] [Revised: 11/09/2023] [Accepted: 11/16/2023] [Indexed: 12/19/2023]
Abstract
Neural tracking of spoken speech is considered a potential clinical biomarker for speech-processing difficulties, but the reliability of neural speech tracking is unclear. Here, younger and older adults listened to stories in two sessions while electroencephalography was recorded to investigate the reliability and generalizability of neural speech tracking. Speech tracking amplitude was larger for older than younger adults, consistent with an age-related loss of inhibition. The reliability of neural speech tracking was moderate (ICC ∼0.5-0.75) and tended to be higher for older adults. However, reliability was lower for speech tracking than for neural responses to noise bursts (ICC >0.8), which we used as a benchmark for maximum reliability. Neural speech tracking generalized moderately across different stories (ICC ∼0.5-0.6), which appeared greatest for audiobook-like stories spoken by the same person. Hence, a variety of stories could possibly be used for clinical assessments. Overall, the current data are important for developing a biomarker of speech processing but suggest that further work is needed to increase the reliability to meet clinical standards.
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Affiliation(s)
- Ryan A Panela
- Rotman Research Institute, Baycrest Academy for Research and Education, M6A 2E1 North York, ON, Canada; Department of Psychology, University of Toronto, M5S 1A1 Toronto, ON, Canada
| | - Francesca Copelli
- Rotman Research Institute, Baycrest Academy for Research and Education, M6A 2E1 North York, ON, Canada; Department of Psychology, University of Toronto, M5S 1A1 Toronto, ON, Canada
| | - Björn Herrmann
- Rotman Research Institute, Baycrest Academy for Research and Education, M6A 2E1 North York, ON, Canada; Department of Psychology, University of Toronto, M5S 1A1 Toronto, ON, Canada.
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13
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Parameshwarappa V, Norena AJ. The effects of acute and chronic noise trauma on stimulus-evoked activity across primary auditory cortex layers. J Neurophysiol 2024; 131:225-240. [PMID: 38198658 DOI: 10.1152/jn.00427.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 12/19/2023] [Accepted: 01/02/2024] [Indexed: 01/12/2024] Open
Abstract
Exposure to intense noise environments is a major cause of sensorineural hearing loss and auditory perception disorders, such as tinnitus and hyperacusis, which may have a central origin. The effects of noise-induced hearing loss on the auditory cortex have been documented in many studies. One limitation of these studies, however, is that the effects of noise trauma have been mostly studied at the granular layer (i.e, the main cortical recipient of thalamic input), while the cortex is a very complex structure, with six different layers each having its own pattern of connectivity and role in sensory processing. The present study aims to investigate the effects of acute and chronic noise trauma on the laminar pattern of stimulus-evoked activity in the primary auditory cortex of the anesthetized guinea pig. We show that acute and chronic noise trauma are both followed by an increase in stimulus-evoked cortical responses, mostly in the granular and supragranular layers. The cortical responses are more monotonic as a function of the intensity level after noise trauma. There was minimal change, if any, in local field potential (LFP) amplitude after acute noise trauma, while LFP amplitude was enhanced after chronic noise trauma. Finally, LFP and the current source density analysis suggest that acute but more specifically chronic noise trauma is associated with the emergence of a new sink in the supragranular layer. This result suggests that supragranular layers become a major input recipient. We discuss the possible mechanisms and functional implications of these changes.NEW & NOTEWORTHY Our study shows that cortical activity is enhanced after trauma and that the sequence of cortical column activation during stimulus-evoked response is altered, i.e. the supragranular layer becomes a major input recipient. We speculate that these large cortical changes may play a key role in the auditory hypersensitivity (hyperacusis) that can be triggered after noise trauma in human subjects.
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Affiliation(s)
- Vinay Parameshwarappa
- Centre National de la Recherche Scientifique, Aix-Marseille University, Marseille, France
| | - Arnaud J Norena
- Centre National de la Recherche Scientifique, Aix-Marseille University, Marseille, France
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14
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Xie R, Wang M, Zhang C. Mechanisms of age-related hearing loss at the auditory nerve central synapses and postsynaptic neurons in the cochlear nucleus. Hear Res 2024; 442:108935. [PMID: 38113793 PMCID: PMC10842789 DOI: 10.1016/j.heares.2023.108935] [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: 10/11/2023] [Revised: 12/04/2023] [Accepted: 12/08/2023] [Indexed: 12/21/2023]
Abstract
Sound information is transduced from mechanical vibration to electrical signals in the cochlea, conveyed to and further processed in the brain to form auditory perception. During the process, spiral ganglion neurons (SGNs) are the key cells that connect the peripheral and central auditory systems by receiving information from hair cells in the cochlea and transmitting it to neurons of the cochlear nucleus (CN). Decades of research in the cochlea greatly improved our understanding of SGN function under normal and pathological conditions, especially about the roles of different subtypes of SGNs and their peripheral synapses. However, it remains less clear how SGN central terminals or auditory nerve (AN) synapses connect to CN neurons, and ultimately how peripheral pathology links to structural alterations and functional deficits in the central auditory nervous system. This review discusses recent progress about the morphological and physiological properties of different subtypes of AN synapses and associated postsynaptic CN neurons, their changes during aging, and the potential mechanisms underlying age-related hearing loss.
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Affiliation(s)
- Ruili Xie
- Department of Otolaryngology, The Ohio State University, 420 W 12th Ave, Columbus OH 43210, USA; Department of Neuroscience, The Ohio State University, 420W 12th Ave, Columbus, OH 43210, USA.
| | - Meijian Wang
- Department of Otolaryngology, The Ohio State University, 420 W 12th Ave, Columbus OH 43210, USA
| | - Chuangeng Zhang
- Department of Otolaryngology, The Ohio State University, 420 W 12th Ave, Columbus OH 43210, USA
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15
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McClaskey CM. Neural hyperactivity and altered envelope encoding in the central auditory system: Changes with advanced age and hearing loss. Hear Res 2024; 442:108945. [PMID: 38154191 PMCID: PMC10942735 DOI: 10.1016/j.heares.2023.108945] [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: 05/25/2023] [Revised: 12/04/2023] [Accepted: 12/22/2023] [Indexed: 12/30/2023]
Abstract
Temporal modulations are ubiquitous features of sound signals that are important for auditory perception. The perception of temporal modulations, or temporal processing, is known to decline with aging and hearing loss and negatively impact auditory perception in general and speech recognition specifically. However, neurophysiological literature also provides evidence of exaggerated or enhanced encoding of specifically temporal envelopes in aging and hearing loss, which may arise from changes in inhibitory neurotransmission and neuronal hyperactivity. This review paper describes the physiological changes to the neural encoding of temporal envelopes that have been shown to occur with age and hearing loss and discusses the role of disinhibition and neural hyperactivity in contributing to these changes. Studies in both humans and animal models suggest that aging and hearing loss are associated with stronger neural representations of both periodic amplitude modulation envelopes and of naturalistic speech envelopes, but primarily for low-frequency modulations (<80 Hz). Although the frequency dependence of these results is generally taken as evidence of amplified envelope encoding at the cortex and impoverished encoding at the midbrain and brainstem, there is additional evidence to suggest that exaggerated envelope encoding may also occur subcortically, though only for envelopes with low modulation rates. A better understanding of how temporal envelope encoding is altered in aging and hearing loss, and the contexts in which neural responses are exaggerated/diminished, may aid in the development of interventions, assistive devices, and treatment strategies that work to ameliorate age- and hearing-loss-related auditory perceptual deficits.
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Affiliation(s)
- Carolyn M McClaskey
- Department of Otolaryngology - Head and Neck Surgery, Medical University of South Carolina, 135 Rutledge Ave, MSC 550, Charleston, SC 29425, United States.
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16
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Butler T, Wang X, Chiang G, Xi K, Niogi S, Glodzik L, Li Y, Razlighi QR, Zhou L, Hojjati SH, Ozsahin I, Mao X, Maloney T, Tanzi E, Rahmouni N, Tissot C, Lussier F, Shah S, Shungu D, Gupta A, De Leon M, Mozley PD, Pascoal TA, Rosa-Neto P. Reduction in Constitutively Activated Auditory Brainstem Microglia in Aging and Alzheimer's Disease. J Alzheimers Dis 2024; 99:307-319. [PMID: 38669537 DOI: 10.3233/jad-231312] [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] [Indexed: 04/28/2024]
Abstract
Background Alzheimer's disease (AD) pathology is considered to begin in the brainstem, and cerebral microglia are known to play a critical role in AD pathogenesis, yet little is known about brainstem microglia in AD. Translocator protein (TSPO) PET, sensitive to activated microglia, shows high signal in dorsal brainstem in humans, but the precise location and clinical correlates of this signal are unknown. Objective To define age and AD associations of brainstem TSPO PET signal in humans. Methods We applied new probabilistic maps of brainstem nuclei to quantify PET-measured TSPO expression over the whole brain including brainstem in 71 subjects (43 controls scanned using 11C-PK11195; 20 controls and 8 AD subjects scanned using 11C-PBR28). We focused on inferior colliculi (IC) because of visually-obvious high signal in this region, and potential relevance to auditory dysfunction in AD. We also assessed bilateral cortex. Results TSPO expression was normally high in IC and other brainstem regions. IC TSPO was decreased with aging (p = 0.001) and in AD subjects versus controls (p = 0.004). In cortex, TSPO expression was increased with aging (p = 0.030) and AD (p = 0.033). Conclusions Decreased IC TSPO expression with aging and AD-an opposite pattern than in cortex-highlights underappreciated regional heterogeneity in microglia phenotype, and implicates IC in a biological explanation for strong links between hearing loss and AD. Unlike in cerebrum, where TSPO expression is considered pathological, activated microglia in IC and other brainstem nuclei may play a beneficial, homeostatic role. Additional study of brainstem microglia in aging and AD is needed.
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Affiliation(s)
- Tracy Butler
- Department of Radiology, Weill Cornell Medicine, New York, NY, USA
| | - Xiuyuan Wang
- Department of Radiology, Weill Cornell Medicine, New York, NY, USA
| | - Gloria Chiang
- Department of Radiology, Weill Cornell Medicine, New York, NY, USA
| | - Ke Xi
- Department of Radiology, Weill Cornell Medicine, New York, NY, USA
| | - Sumit Niogi
- Department of Radiology, Weill Cornell Medicine, New York, NY, USA
| | - Lidia Glodzik
- Department of Radiology, Weill Cornell Medicine, New York, NY, USA
| | - Yi Li
- Department of Radiology, Weill Cornell Medicine, New York, NY, USA
| | | | - Liangdong Zhou
- Department of Radiology, Weill Cornell Medicine, New York, NY, USA
| | | | - Ilker Ozsahin
- Department of Radiology, Weill Cornell Medicine, New York, NY, USA
| | - Xiangling Mao
- Department of Radiology, Weill Cornell Medicine, New York, NY, USA
| | - Thomas Maloney
- Department of Radiology, Weill Cornell Medicine, New York, NY, USA
| | - Emily Tanzi
- Department of Radiology, Weill Cornell Medicine, New York, NY, USA
| | - Nesrine Rahmouni
- Translational Neuroimaging Laboratory, The McGill University Research Centre for Studies in Aging, Montréal, QC, Canada
| | - Cécile Tissot
- Translational Neuroimaging Laboratory, The McGill University Research Centre for Studies in Aging, Montréal, QC, Canada
| | - Firoza Lussier
- Translational Neuroimaging Laboratory, The McGill University Research Centre for Studies in Aging, Montréal, QC, Canada
| | - Sudhin Shah
- Department of Radiology, Weill Cornell Medicine, New York, NY, USA
| | - Dikoma Shungu
- Department of Radiology, Weill Cornell Medicine, New York, NY, USA
| | - Ajay Gupta
- Department of Radiology, Weill Cornell Medicine, New York, NY, USA
| | - Mony De Leon
- Department of Radiology, Weill Cornell Medicine, New York, NY, USA
| | - P David Mozley
- Department of Radiology, Weill Cornell Medicine, New York, NY, USA
| | - Tharick A Pascoal
- Departments of Neurology and Psychiatry, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Pedro Rosa-Neto
- Translational Neuroimaging Laboratory, The McGill University Research Centre for Studies in Aging, Montréal, QC, Canada
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17
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Park CR, Willott JF, Walton JP. Age-related changes of auditory sensitivity across the life span of CBA/CaJ mice. Hear Res 2024; 441:108921. [PMID: 38042127 PMCID: PMC10843596 DOI: 10.1016/j.heares.2023.108921] [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: 08/04/2023] [Revised: 10/29/2023] [Accepted: 11/20/2023] [Indexed: 12/04/2023]
Abstract
The inbred mouse strain CBA/CaJ is a frequently used animal model of age-related hearing loss in humans. These mice display significant hearing loss at a relatively advanced age, similar to most humans, with progressive loss of hearing as the mouse continues to age. While important descriptions of hearing loss in this mouse strain at multiple ages have previously been published, shortcomings persist in the data for hearing over the lifespan of the mouse. Therefore, we analyzed auditory brainstem response threshold data from records maintained by our research group to yield an extensive database of thresholds over nearly the entire life span of the CBA/CaJ mouse (from 79 to 1085 days). Data was collected from in-house bred mice of CBA/CaJ stock, initially from The Jackson Laboratory. Data was collected using BiosigRZ software and TDT System III hardware. Thresholds were routinely measured in conjunction with behavioral and electrophysiological experiments; only responses from baseline or experimentally naïve animals were analyzed. The resulting data set comprised 376 female mice and 441 males. At the lowest and highest frequencies (8 & 32 kHz), initial thresholds were just under 30 dB SPL and increased slowly until they were significantly different at 16-18 months compared to 1-3 months age, with the difference increasing over subsequent ages. At the middle frequencies (12 & 16 kHz), initial thresholds were just under 20 dB SPL and increased until they became different from initial at 16-18 months. At 24 kHz, initial thresholds were just above 20 dB and became different from initial at 13-16 months of age. The rate of change of thresholds with age were similar for all frequencies until about 30 months of age, when 32 kHz threshold changes lagged behind other frequencies. Generally, CBA/CaJ mice in our colony display relatively low thresholds until approximately 16 months of age, depending on frequency. After 16-18 months, thresholds become significantly worse. After approximately 20-22 months thresholds increase linearly with age.
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Affiliation(s)
- Collin R Park
- Global Center for Hearing and Speech Research, University of South Florida, Tampa, FL, United States; Department of Communication Sciences and Disorders, University of South Florida, Tampa, FL, United States
| | - James F Willott
- Department of Communication Sciences and Disorders, University of South Florida, Tampa, FL, United States
| | - Joseph P Walton
- Global Center for Hearing and Speech Research, University of South Florida, Tampa, FL, United States; Department of Communication Sciences and Disorders, University of South Florida, Tampa, FL, United States.
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18
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Diao T, Ma X, Fang X, Duan M, Yu L. Compensation in neuro-system related to age-related hearing loss. Acta Otolaryngol 2024; 144:30-34. [PMID: 38265951 DOI: 10.1080/00016489.2023.2295400] [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: 12/07/2023] [Accepted: 12/10/2023] [Indexed: 01/26/2024]
Abstract
BACKGROUND Age-related hearing loss (ARHL) is a major cause of chronic disability among the elderly. Individuals with ARHL not only have trouble hearing sounds, but also with speech perception. As the perception of auditory information is reliant on integration between widespread brain networks to interpret auditory stimuli, both auditory and extra-auditory systems which mainly include visual, motor and attention systems, play an important role in compensating for ARHL. OBJECTIVES To better understand the compensatory mechanism of ARHL and inspire better interventions that may alleviate ARHL. METHODS We mainly focus on the existing information on ARHL-related central compensation. The compensatory effects of hearing aids (HAs) and cochlear implants (CIs) on ARHL were also discussed. RESULTS Studies have shown that ARHL can induce cochlear hair cell damage or loss and cochlear synaptopathy, which could induce central compensation including compensation of auditory and extra-auditory neural networks. The use of HAs and CIs can improve bottom-up processing by enabling 'better' input to the auditory pathways and then to the cortex by enhancing the diminished auditory signal. CONCLUSIONS The central compensation of ARHL and its possible correlation with HAs and CIs are current hotspots in the field and should be given focus in future research.
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Affiliation(s)
- Tongxiang Diao
- Department of Otolaryngology, Head and Neck Surgery, People's Hospital, Peking University, Beijing, China
| | - Xin Ma
- Department of Otolaryngology, Head and Neck Surgery, People's Hospital, Peking University, Beijing, China
| | - Xuan Fang
- Department of Human Anatomy, Histology & Embryology, School of Basic Medical Sciences, Peking University, Beijing, China
| | - Maoli Duan
- Department of Clinical Science, Intervention and Technology, Karolinska Institute, Stockholm, Sweden
- Department of Otolaryngology, Head and Neck Surgery & Audiology and Neurotology, Karolinska University Hospital, Karolinska Institute, Stockholm, Sweden
| | - Lisheng Yu
- Department of Otolaryngology, Head and Neck Surgery, People's Hospital, Peking University, Beijing, China
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19
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Kreft HA, Oxenham AJ. Auditory enhancement in younger and older listeners with normal and impaired hearinga). THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2023; 154:3821-3832. [PMID: 38109406 PMCID: PMC10730236 DOI: 10.1121/10.0023937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Revised: 11/17/2023] [Accepted: 11/20/2023] [Indexed: 12/20/2023]
Abstract
Auditory enhancement is a spectral contrast aftereffect that can facilitate the detection of novel events in an ongoing background. A single-interval paradigm combined with roved frequency content between trials can yield as much as 20 dB enhancement in young normal-hearing listeners. This study compared such enhancement in 15 listeners with sensorineural hearing loss with that in 15 age-matched adults and 15 young adults with normal audiograms. All groups were presented with stimulus levels of 70 dB sound pressure level (SPL) per component. The two groups with normal hearing were also tested at 45 dB SPL per component. The hearing-impaired listeners showed very little enhancement overall. However, when tested at the same high (70-dB) level, both young and age-matched normal-hearing listeners also showed substantially reduced enhancement, relative to that found at 45 dB SPL. Some differences in enhancement emerged between young and older normal-hearing listeners at the lower sound level. The results suggest that enhancement is highly level-dependent and may also decrease somewhat with age or slight hearing loss. Implications for hearing-impaired listeners may include a poorer ability to adapt to real-world acoustic variability, due in part to the higher levels at which sound must be presented to be audible.
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Affiliation(s)
- Heather A Kreft
- Department of Psychology, University of Minnesota, Elliott Hall, 75 East River Parkway, Minneapolis, Minnesota 55455, USA
| | - Andrew J Oxenham
- Department of Psychology, University of Minnesota, Elliott Hall, 75 East River Parkway, Minneapolis, Minnesota 55455, USA
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20
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Almassri LS, Ohl AP, Iafrate MC, Wade AD, Tokar NJ, Mafi AM, Beebe NL, Young JW, Mellott JG. Age-related upregulation of perineuronal nets on inferior collicular cells that project to the cochlear nucleus. Front Aging Neurosci 2023; 15:1271008. [PMID: 38053844 PMCID: PMC10694216 DOI: 10.3389/fnagi.2023.1271008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 10/26/2023] [Indexed: 12/07/2023] Open
Abstract
Introduction Disruptions to the balance of excitation and inhibition in the inferior colliculus (IC) occur during aging and underlie various aspects of hearing loss. Specifically, the age-related alteration to GABAergic neurotransmission in the IC likely contributes to the poorer temporal precision characteristic of presbycusis. Perineuronal nets (PNs), a specialized form of the extracellular matrix, maintain excitatory/inhibitory synaptic environments and reduce structural plasticity. We sought to determine whether PNs increasingly surround cell populations in the aged IC that comprise excitatory descending projections to the cochlear nucleus. Method We combined Wisteria floribunda agglutinin (WFA) staining for PNs with retrograde tract-tracing in three age groups of Fischer Brown Norway (FBN) rats. Results The data demonstrate that the percentage of IC-CN cells with a PN doubles from ~10% at young age to ~20% at old age. This was true in both lemniscal and non-lemniscal IC. Discussion Furthermore, the increase of PNs occurred on IC cells that make both ipsilateral and contralateral descending projections to the CN. These results indicate that reduced structural plasticity in the elderly IC-CN pathway, affecting excitatory/inhibitory balance and, potentially, may lead to reduced temporal precision associated with presbycusis.
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Affiliation(s)
- Laila S. Almassri
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, OH, United States
| | - Andrew P. Ohl
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, OH, United States
| | - Milena C. Iafrate
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, OH, United States
- Department of Biological Sciences, Kent State University, Kent, OH, United States
| | - Aidan D. Wade
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, OH, United States
- Department of Biological Sciences, Kent State University, Kent, OH, United States
| | - Nick J. Tokar
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, OH, United States
| | - Amir M. Mafi
- The Ohio State College of Medicine, The Ohio State, Columbus, OH, United States
| | - Nichole L. Beebe
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, OH, United States
| | - Jesse W. Young
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, OH, United States
| | - Jeffrey G. Mellott
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, OH, United States
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21
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Heeringa AN, Jüchter C, Beutelmann R, Klump GM, Köppl C. Altered neural encoding of vowels in noise does not affect behavioral vowel discrimination in gerbils with age-related hearing loss. Front Neurosci 2023; 17:1238941. [PMID: 38033551 PMCID: PMC10682387 DOI: 10.3389/fnins.2023.1238941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Accepted: 10/24/2023] [Indexed: 12/02/2023] Open
Abstract
Introduction Understanding speech in a noisy environment, as opposed to speech in quiet, becomes increasingly more difficult with increasing age. Using the quiet-aged gerbil, we studied the effects of aging on speech-in-noise processing. Specifically, behavioral vowel discrimination and the encoding of these vowels by single auditory-nerve fibers were compared, to elucidate some of the underlying mechanisms of age-related speech-in-noise perception deficits. Methods Young-adult and quiet-aged Mongolian gerbils, of either sex, were trained to discriminate a deviant naturally-spoken vowel in a sequence of vowel standards against a speech-like background noise. In addition, we recorded responses from single auditory-nerve fibers of young-adult and quiet-aged gerbils while presenting the same speech stimuli. Results Behavioral vowel discrimination was not significantly affected by aging. For both young-adult and quiet-aged gerbils, the behavioral discrimination between /eː/ and /iː/ was more difficult to make than /eː/ vs. /aː/ or /iː/ vs. /aː/, as evidenced by longer response times and lower d' values. In young-adults, spike timing-based vowel discrimination agreed with the behavioral vowel discrimination, while in quiet-aged gerbils it did not. Paradoxically, discrimination between vowels based on temporal responses was enhanced in aged gerbils for all vowel comparisons. Representation schemes, based on the spectrum of the inter-spike interval histogram, revealed stronger encoding of both the fundamental and the lower formant frequencies in fibers of quiet-aged gerbils, but no qualitative changes in vowel encoding. Elevated thresholds in combination with a fixed stimulus level, i.e., lower sensation levels of the stimuli for old individuals, can explain the enhanced temporal coding of the vowels in noise. Discussion These results suggest that the altered auditory-nerve discrimination metrics in old gerbils may mask age-related deterioration in the central (auditory) system to the extent that behavioral vowel discrimination matches that of the young adults.
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Affiliation(s)
- Amarins N. Heeringa
- Research Centre Neurosensory Science and Cluster of Excellence “Hearing4all”, Department of Neuroscience, School of Medicine and Health Science, Carl von Ossietzky University Oldenburg, Oldenburg, Germany
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Parameshwarappa V, Siponen M, Watabe I, Karkaba A, Galazyuk A, Noreña A. Noise-Induced Hearing Loss Alters Potassium-Chloride CoTransporter KCC2 and GABA Inhibition in the auditory centers. RESEARCH SQUARE 2023:rs.3.rs-3389804. [PMID: 37886592 PMCID: PMC10602088 DOI: 10.21203/rs.3.rs-3389804/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2023]
Abstract
Homeostatic plasticity, the ability of neurons to maintain their averaged activity constant around a set point value, is thought to account for the central hyperactivity after hearing loss. Here, we investigated the putative role of GABAergic neurotransmission in this mechanism after a noise-induced hearing loss larger than 50 dB in high frequencies in guinea pigs. The effect of GABAergic inhibition is linked to the normal functioning of K+-Cl- co-transporter isoform 2 (KCC2) which maintains a low intracellular concentration of chloride. The expression of membrane KCC2 were investigated before after noise trauma in the ventral and dorsal cochlear nucleus (VCN and DCN, respectively) and in the inferior colliculus (IC). Moreover, the effect of gabazine (GBZ), a GABA antagonist, was also studied on the neural activity in IC. We show that KCC2 is downregulated in VCN, DCN and IC 3 days after noise trauma, and in DCN and IC 30 days after the trauma. As expected, GBZ application in the IC of control animals resulted in an increase of spontaneous and stimulus-evoked activity. In the noise exposed animals, on the other hand, GBZ application decreased the stimulus-evoked activity in IC neurons. The functional implications of these central changes are discussed.
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Affiliation(s)
| | - Marina Siponen
- Centre National de la Recherche Scientifique, Aix- Marseille University
| | - Isabelle Watabe
- Centre National de la Recherche Scientifique, Aix- Marseille University
| | - Alaa Karkaba
- Centre National de la Recherche Scientifique, Aix- Marseille University
| | | | - Arnaud Noreña
- Centre National de la Recherche Scientifique, Aix- Marseille University
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23
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Füllgrabe C, Fontan L, Vidal É, Massari H, Moore BCJ. Effects of hearing loss, age, noise exposure, and listening skills on envelope regularity discrimination. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2023; 154:2453-2461. [PMID: 37850836 DOI: 10.1121/10.0021884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Accepted: 10/03/2023] [Indexed: 10/19/2023]
Abstract
The envelope regularity discrimination (ERD) test assesses the ability to discriminate irregular from regular amplitude modulation (AM). The measured threshold is called the irregularity index (II). It was hypothesized that the II at threshold should be almost unaffected by the loudness recruitment that is associated with cochlear hearing loss because the effect of recruitment is similar to multiplying the AM depth by a certain factor, and II values depend on the amount of envelope irregularity relative to the baseline modulation depth. To test this hypothesis, the ERD test was administered to 60 older adults with varying degrees of hearing loss, using carrier frequencies of 1 and 4 kHz. The II values for the two carrier frequencies were highly correlated, indicating that the ERD test was measuring a consistent characteristic of each subject. The II values at 1 and 4 kHz were not significantly correlated with the audiometric thresholds at the corresponding frequencies, consistent with the hypothesis. The II values at 4 kHz were significantly positively correlated with age. There was an unexpected negative correlation between II values and a measure of noise exposure. This is argued to reflect the confounding effects of listening skills.
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Affiliation(s)
- Christian Füllgrabe
- Ear Institute, University College London, 332 Gray's Inn Road, London, WC1X 8EE, United Kingdom
| | | | | | | | - Brian C J Moore
- Department of Psychology, University of Cambridge, Downing Street, Cambridge, CB2 3EB, United Kingdom
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Xu N, Qin X, Zhou Z, Shan W, Ren J, Yang C, Lu L, Wang Q. Age differentially modulates the cortical tracking of the lower and higher level linguistic structures during speech comprehension. Cereb Cortex 2023; 33:10463-10474. [PMID: 37566910 DOI: 10.1093/cercor/bhad296] [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: 12/10/2022] [Revised: 07/23/2023] [Accepted: 07/24/2023] [Indexed: 08/13/2023] Open
Abstract
Speech comprehension requires listeners to rapidly parse continuous speech into hierarchically-organized linguistic structures (i.e. syllable, word, phrase, and sentence) and entrain the neural activities to the rhythm of different linguistic levels. Aging is accompanied by changes in speech processing, but it remains unclear how aging affects different levels of linguistic representation. Here, we recorded magnetoencephalography signals in older and younger groups when subjects actively and passively listened to the continuous speech in which hierarchical linguistic structures of word, phrase, and sentence were tagged at 4, 2, and 1 Hz, respectively. A newly-developed parameterization algorithm was applied to separate the periodically linguistic tracking from the aperiodic component. We found enhanced lower-level (word-level) tracking, reduced higher-level (phrasal- and sentential-level) tracking, and reduced aperiodic offset in older compared with younger adults. Furthermore, we observed the attentional modulation on the sentential-level tracking being larger for younger than for older ones. Notably, the neuro-behavior analyses showed that subjects' behavioral accuracy was positively correlated with the higher-level linguistic tracking, reversely correlated with the lower-level linguistic tracking. Overall, these results suggest that the enhanced lower-level linguistic tracking, reduced higher-level linguistic tracking and less flexibility of attentional modulation may underpin aging-related decline in speech comprehension.
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Affiliation(s)
- Na Xu
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China
- National Clinical Research Center for Neurological Diseases, Beijing 100070, China
| | - Xiaoxiao Qin
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China
- National Clinical Research Center for Neurological Diseases, Beijing 100070, China
| | - Ziqi Zhou
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China
- National Clinical Research Center for Neurological Diseases, Beijing 100070, China
| | - Wei Shan
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China
- National Clinical Research Center for Neurological Diseases, Beijing 100070, China
| | - Jiechuan Ren
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China
- National Clinical Research Center for Neurological Diseases, Beijing 100070, China
| | - Chunqing Yang
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China
- National Clinical Research Center for Neurological Diseases, Beijing 100070, China
| | - Lingxi Lu
- Center for the Cognitive Science of Language, Beijing Language and Culture University, Beijing 100083, China
| | - Qun Wang
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China
- National Clinical Research Center for Neurological Diseases, Beijing 100070, China
- Beijing Institute of Brain Disorders, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing 100069, China
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25
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Castelli V, d'Angelo M, Zazzeroni F, Vecchiotti D, Alesse E, Capece D, Brandolini L, Cattani F, Aramini A, Allegretti M, Cimini A. Intranasal delivery of NGF rescues hearing impairment in aged SAMP8 mice. Cell Death Dis 2023; 14:605. [PMID: 37704645 PMCID: PMC10499813 DOI: 10.1038/s41419-023-06100-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 08/11/2023] [Accepted: 08/21/2023] [Indexed: 09/15/2023]
Abstract
Hearing loss impacts the quality of life and affects communication resulting in social isolation and reduced well-being. Despite its impact on society and economy, no therapies for age-related hearing loss are available so far. Loss of mechanosensory hair cells of the cochlea is a common event of hearing loss in humans. Studies performed in birds demonstrating that they can be replaced following the proliferation and transdifferentiation of supporting cells, strongly pointed out on HCs regeneration as the main focus of research aimed at hearing regeneration. Neurotrophins are growth factors involved in neuronal survival, development, differentiation, and plasticity. NGF has been involved in the interplay between auditory receptors and efferent innervation in the cochlea during development. During embryo development, both NGF and its receptors are highly expressed in the inner ears. It has been reported that NGF is implicated in the differentiation of auditory gangliar and hair cells. Thus, it has been proposed that NGF administration can decrease neuronal damage and prevent hearing loss. The main obstacle to the development of hearing impairment therapy is that efficient means of delivery for selected drugs to the cochlea are missing. Herein, in this study NGF was administered by the intranasal route. The first part of the study was focused on a biodistribution study, which showed the effective delivery in the cochlea; while the second part was focused on analyzing the potential therapeutic effect of NGF in senescence-accelerated prone strain 8 mice. Interestingly, intranasal administration of NGF resulted protective in counteracting hearing impairment in SAMP8 mice, ameliorating hearing performances (analyzed by auditory brainstem responses and distortion product otoacoustic emission) and hair cells morphology (analyzed by microscopy analysis). The results obtained were encouraging indicating that the neurotrophin NGF was efficiently delivered to the inner ear and that it was effective in counteracting hearing loss.
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Affiliation(s)
- Vanessa Castelli
- Department of Life, Health and Environmental Sciences, University of L'Aquila, L'Aquila, Italy
| | - Michele d'Angelo
- Department of Life, Health and Environmental Sciences, University of L'Aquila, L'Aquila, Italy
| | - Francesca Zazzeroni
- Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, L'Aquila, Italy.
| | - Davide Vecchiotti
- Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, L'Aquila, Italy
| | - Edoardo Alesse
- Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, L'Aquila, Italy
| | - Daria Capece
- Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, L'Aquila, Italy
| | | | - Franca Cattani
- Dompé Farmaceutici Spa, Via Campo di Pile 1, L'Aquila, Italy
| | - Andrea Aramini
- Dompé Farmaceutici Spa, Via Campo di Pile 1, L'Aquila, Italy
| | | | - Annamaria Cimini
- Department of Life, Health and Environmental Sciences, University of L'Aquila, L'Aquila, Italy.
- Sbarro Institute for Cancer Research and Molecular Medicine, Department of Biology, Temple University, Philadelphia, PA, USA.
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Tureček R, Melichar A, Králíková M, Hrušková B. The role of GABA B receptors in the subcortical pathways of the mammalian auditory system. Front Endocrinol (Lausanne) 2023; 14:1195038. [PMID: 37635966 PMCID: PMC10456889 DOI: 10.3389/fendo.2023.1195038] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Accepted: 07/24/2023] [Indexed: 08/29/2023] Open
Abstract
GABAB receptors are G-protein coupled receptors for the inhibitory neurotransmitter GABA. Functional GABAB receptors are formed as heteromers of GABAB1 and GABAB2 subunits, which further associate with various regulatory and signaling proteins to provide receptor complexes with distinct pharmacological and physiological properties. GABAB receptors are widely distributed in nervous tissue, where they are involved in a number of processes and in turn are subject to a number of regulatory mechanisms. In this review, we summarize current knowledge of the cellular distribution and function of the receptors in the inner ear and auditory pathway of the mammalian brainstem and midbrain. The findings suggest that in these regions, GABAB receptors are involved in processes essential for proper auditory function, such as cochlear amplifier modulation, regulation of spontaneous activity, binaural and temporal information processing, and predictive coding. Since impaired GABAergic inhibition has been found to be associated with various forms of hearing loss, GABAB dysfunction could also play a role in some pathologies of the auditory system.
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Affiliation(s)
- Rostislav Tureček
- Department of Auditory Neuroscience, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, Prague, Czechia
| | - Adolf Melichar
- Department of Auditory Neuroscience, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, Prague, Czechia
- Second Faculty of Medicine, Charles University, Prague, Czechia
| | - Michaela Králíková
- Department of Auditory Neuroscience, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, Prague, Czechia
| | - Bohdana Hrušková
- Department of Auditory Neuroscience, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, Prague, Czechia
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27
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Sodero AO, Castagna VC, Elorza SD, Gonzalez-Rodulfo SM, Paulazo MA, Ballestero JA, Martin MG, Gomez-Casati ME. Phytosterols reverse antiretroviral-induced hearing loss, with potential implications for cochlear aging. PLoS Biol 2023; 21:e3002257. [PMID: 37619212 PMCID: PMC10449472 DOI: 10.1371/journal.pbio.3002257] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Accepted: 07/18/2023] [Indexed: 08/26/2023] Open
Abstract
Cholesterol contributes to neuronal membrane integrity, supports membrane protein clustering and function, and facilitates proper signal transduction. Extensive evidence has shown that cholesterol imbalances in the central nervous system occur in aging and in the development of neurodegenerative diseases. In this work, we characterize cholesterol homeostasis in the inner ear of young and aged mice as a new unexplored possibility for the prevention and treatment of hearing loss. Our results show that cholesterol levels in the inner ear are reduced during aging, an effect that is associated with an increased expression of the cholesterol 24-hydroxylase (CYP46A1), the main enzyme responsible for cholesterol turnover in the brain. In addition, we show that pharmacological activation of CYP46A1 with the antiretroviral drug efavirenz reduces the cholesterol content in outer hair cells (OHCs), leading to a decrease in prestin immunolabeling and resulting in an increase in the distortion product otoacoustic emissions (DPOAEs) thresholds. Moreover, dietary supplementation with phytosterols, plant sterols with structure and function similar to cholesterol, was able to rescue the effect of efavirenz administration on the auditory function. Altogether, our findings point towards the importance of cholesterol homeostasis in the inner ear as an innovative therapeutic strategy in preventing and/or delaying hearing loss.
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Affiliation(s)
- Alejandro O. Sodero
- Instituto de Investigaciones Biomédicas, Pontificia Universidad Católica Argentina, Consejo Nacional de Investigaciones Científicas y Técnicas (BIOMED, UCA-CONICET), Buenos Aires, Argentina
| | - Valeria C. Castagna
- Instituto de Farmacología, Facultad de Medicina, Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, Dr. Héctor N. Torres, Consejo Nacional de Investigaciones Científicas y Técnicas (INGEBI-CONICET), Buenos Aires, Argentina
| | - Setiembre D. Elorza
- Laboratorio de Neurobiología, Instituto de Investigaciones Médicas Mercedes y Martín Ferreyra, Consejo Nacional de Investigaciones Científicas y Técnicas (INIMEC-CONICET-UNC), Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Sara M. Gonzalez-Rodulfo
- Instituto de Investigaciones Biomédicas, Pontificia Universidad Católica Argentina, Consejo Nacional de Investigaciones Científicas y Técnicas (BIOMED, UCA-CONICET), Buenos Aires, Argentina
| | - María A. Paulazo
- Instituto de Investigaciones Biomédicas, Pontificia Universidad Católica Argentina, Consejo Nacional de Investigaciones Científicas y Técnicas (BIOMED, UCA-CONICET), Buenos Aires, Argentina
| | - Jimena A. Ballestero
- Instituto de Farmacología, Facultad de Medicina, Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Mauricio G. Martin
- Laboratorio de Neurobiología, Instituto de Investigaciones Médicas Mercedes y Martín Ferreyra, Consejo Nacional de Investigaciones Científicas y Técnicas (INIMEC-CONICET-UNC), Universidad Nacional de Córdoba, Córdoba, Argentina
| | - María Eugenia Gomez-Casati
- Instituto de Farmacología, Facultad de Medicina, Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
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28
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O'Dowd A, Hirst RJ, Setti A, Donoghue OA, Kenny RA, Newell FN. The temporal precision of audiovisual integration is associated with longitudinal fall incidents but not sensorimotor fall risk in older adults. Sci Rep 2023; 13:7167. [PMID: 37137879 PMCID: PMC10156851 DOI: 10.1038/s41598-023-32404-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Accepted: 03/27/2023] [Indexed: 05/05/2023] Open
Abstract
Sustained multisensory integration over long inter-stimulus time delays is typically found in older adults, particularly those with a history of falls. However, the extent to which the temporal precision of audio-visual integration is associated with longitudinal fall or fall risk trajectories is unknown. A large sample of older adults (N = 2319) were grouped into longitudinal trajectories of self-reported fall incidents (i.e., decrease, stable, or increase in number) and, separately, their performance on a standard, objective measure of fall risk, Timed Up and Go (TUG; stable, moderate decline, severe decline). Multisensory integration was measured once as susceptibility to the Sound-Induced Flash Illusion (SIFI) across three stimulus onset asynchronies (SOAs): 70 ms, 150 ms and 230 ms. Older adults with an increasing fall number showed a significantly different pattern of performance on the SIFI than non-fallers, depending on age: For adults with increasing incidents of falls, those aged 53-59 years showed a much smaller difference in illusion susceptibility at 70 ms versus 150 ms than those aged 70 + years. In contrast, non-fallers showed a more comparable difference between these SOA conditions across age groups. There was no association between TUG performance trajectories and SIFI susceptibility. These findings suggests that a fall event is associated with distinct temporal patterns of multisensory integration in ageing and have implications for our understanding of the mechanisms underpinning brain health in older age.
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Affiliation(s)
- Alan O'Dowd
- School of Psychology and Institute of Neuroscience, Trinity College Green, Dublin 2, D02 PN40, Ireland.
- The Irish Longitudinal Study on Ageing, Trinity College Dublin, Dublin, Ireland.
| | - Rebecca J Hirst
- School of Psychology and Institute of Neuroscience, Trinity College Green, Dublin 2, D02 PN40, Ireland
- The Irish Longitudinal Study on Ageing, Trinity College Dublin, Dublin, Ireland
| | - Annalisa Setti
- The Irish Longitudinal Study on Ageing, Trinity College Dublin, Dublin, Ireland
- School of Applied Psychology, University College Cork, Cork, Ireland
| | - Orna A Donoghue
- The Irish Longitudinal Study on Ageing, Trinity College Dublin, Dublin, Ireland
| | - Rose Anne Kenny
- The Irish Longitudinal Study on Ageing, Trinity College Dublin, Dublin, Ireland
- Mercer Institute for Successful Ageing, St. James Hospital, Dublin, Ireland
| | - Fiona N Newell
- School of Psychology and Institute of Neuroscience, Trinity College Green, Dublin 2, D02 PN40, Ireland
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Ye Y, Mattingly MM, Sunthimer MJ, Gay JD, Rosen MJ. Early-Life Stress Impairs Perception and Neural Encoding of Rapid Signals in the Auditory Pathway. J Neurosci 2023; 43:3232-3244. [PMID: 36973014 PMCID: PMC10162457 DOI: 10.1523/jneurosci.1787-22.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 01/24/2023] [Accepted: 03/03/2023] [Indexed: 03/29/2023] Open
Abstract
During developmental critical periods (CPs), early-life stress (ELS) induces cognitive deficits and alters neural circuitry in regions underlying learning, memory, and attention. Mechanisms underlying critical period plasticity are shared by sensory cortices and these higher neural regions, suggesting that sensory processing may also be vulnerable to ELS. In particular, the perception and auditory cortical (ACx) encoding of temporally-varying sounds both mature gradually, even into adolescence, providing an extended postnatal window of susceptibility. To examine the effects of ELS on temporal processing, we developed a model of ELS in the Mongolian gerbil, a well-established model for auditory processing. In both male and female animals, ELS induction impaired the behavioral detection of short gaps in sound, which are critical for speech perception. This was accompanied by reduced neural responses to gaps in auditory cortex, the auditory periphery, and auditory brainstem. ELS thus degrades the fidelity of sensory representations available to higher regions, and could contribute to well-known ELS-induced problems with cognition.SIGNIFICANCE STATEMENT In children and animal models, early-life stress (ELS) leads to deficits in cognition, including problems with learning, memory, and attention. Such problems could arise in part from a low-fidelity representation of sensory information available to higher-level neural regions. Here, we demonstrate that ELS degrades sensory responses to rapid variations in sound at multiple levels of the auditory pathway, and concurrently impairs perception of these rapidly-varying sounds. As these sound variations are intrinsic to speech, ELS may thus pose a challenge to communication and cognition through impaired sensory encoding.
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Affiliation(s)
- Yi Ye
- Hearing Research Group, Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, Ohio, 44272
- Brain Health Research Institute, Kent State University, Kent, Ohio, 44242
| | - Michelle M Mattingly
- Hearing Research Group, Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, Ohio, 44272
| | - Matthew J Sunthimer
- Hearing Research Group, Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, Ohio, 44272
| | - Jennifer D Gay
- Hearing Research Group, Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, Ohio, 44272
- Department of Otolaryngology, Head and Neck Surgery, Rutgers Robert Wood Johnson Medical School, New Brunswick, New Jersey, 08901
| | - Merri J Rosen
- Hearing Research Group, Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, Ohio, 44272
- Brain Health Research Institute, Kent State University, Kent, Ohio, 44242
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Koehler CC, Almassri LS, Tokar N, Mafi AM, O’Hara MJ, Young JW, Mellott JG. Age-related Changes of GAD1 mRNA Expression in the Central Inferior Colliculus. TRANSLATIONAL MEDICINE OF AGING 2023; 7:20-32. [PMID: 38111912 PMCID: PMC10727507 DOI: 10.1016/j.tma.2023.04.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2023] Open
Abstract
Encoding sounds with a high degree of temporal precision is an essential task for the inferior colliculus (IC) to perform and maintain the accurate processing of sounds and speech. However, the age-related reduction of GABAergic neurotransmission in the IC interrupts temporal precision and likely contributes to presbycusis. As presbycusis often manifests at high or low frequencies specifically, we sought to determine if the expression of mRNA for glutamic decarboxylase 1 (GAD1) is downregulated non-uniformly across the tonotopic axis or cell size range in the aging IC. Using single molecule in situ fluorescent hybridization across young, middle age and old Fisher Brown Norway rats (an aging model that acquires low frequency presbycusis) we quantified individual GAD1 mRNA in small, medium and large GABAergic cells. Our results demonstrate that small GABAergic cells in low frequency regions had ~58% less GAD1 in middle age and continued to decline into old age. In contrast, the amount of GAD1 mRNA in large cells in low frequency regions significantly increased with age. As several studies have shown that downregulation of GAD1 decreases the release of GABA, we interpret our results in two ways. First, the onset of presbycusis may be driven by small GABAergic cells downregulating GAD1. Second, as previous studies demonstrate that GAD67 expression is broadly downregulated in the old IC, perhaps the translation of GAD1 to GAD67 is interrupted in large GABAergic IC cells during aging. These results point to a potential genetic mechanism explaining reduced temporal precision in the aging IC, and in turn, presbycusis.
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Affiliation(s)
- Christina C. Koehler
- Department of Anatomy and Neurobiology Northeast Ohio Medical University Rootstown, OH USA
| | - Laila S. Almassri
- Department of Anatomy and Neurobiology Northeast Ohio Medical University Rootstown, OH USA
| | - Nick Tokar
- Department of Anatomy and Neurobiology Northeast Ohio Medical University Rootstown, OH USA
| | - Amir M. Mafi
- The Ohio State College of Medicine The Ohio State Columbus, OH USA
| | - Mitchell J. O’Hara
- Department of Anatomy and Neurobiology Northeast Ohio Medical University Rootstown, OH USA
| | - Jesse W. Young
- Department of Anatomy and Neurobiology Northeast Ohio Medical University Rootstown, OH USA
| | - Jeffrey G. Mellott
- Department of Anatomy and Neurobiology Northeast Ohio Medical University Rootstown, OH USA
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Pisani A, Paciello F, Del Vecchio V, Malesci R, De Corso E, Cantone E, Fetoni AR. The Role of BDNF as a Biomarker in Cognitive and Sensory Neurodegeneration. J Pers Med 2023; 13:jpm13040652. [PMID: 37109038 PMCID: PMC10140880 DOI: 10.3390/jpm13040652] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 04/04/2023] [Accepted: 04/08/2023] [Indexed: 04/29/2023] Open
Abstract
Brain-derived neurotrophic factor (BDNF) has a crucial function in the central nervous system and in sensory structures including olfactory and auditory systems. Many studies have highlighted the protective effects of BDNF in the brain, showing how it can promote neuronal growth and survival and modulate synaptic plasticity. On the other hand, conflicting data about BDNF expression and functions in the cochlear and in olfactory structures have been reported. Several clinical and experimental research studies showed alterations in BDNF levels in neurodegenerative diseases affecting the central and peripheral nervous system, suggesting that BDNF can be a promising biomarker in most neurodegenerative conditions, including Alzheimer's disease, shearing loss, or olfactory impairment. Here, we summarize current research concerning BDNF functions in brain and in sensory domains (olfaction and hearing), focusing on the effects of the BDNF/TrkB signalling pathway activation in both physiological and pathological conditions. Finally, we review significant studies highlighting the possibility to target BDNF as a biomarker in early diagnosis of sensory and cognitive neurodegeneration, opening new opportunities to develop effective therapeutic strategies aimed to counteract neurodegeneration.
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Affiliation(s)
- Anna Pisani
- Department of Otolaryngology Head and Neck Surgery, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
| | - Fabiola Paciello
- Department of Neuroscience, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy
| | - Valeria Del Vecchio
- Department of Neuroscience, Reproductive Sciences and Dentistry-Audiology Section, University of Naples Federico II, 80131 Naples, Italy
| | - Rita Malesci
- Department of Neuroscience, Reproductive Sciences and Dentistry-Audiology Section, University of Naples Federico II, 80131 Naples, Italy
| | - Eugenio De Corso
- Department of Otolaryngology Head and Neck Surgery, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy
| | - Elena Cantone
- Department of Neuroscience, Reproductive Sciences and Dentistry-ENT Section, University of Naples Federico II, 80131 Naples, Italy
| | - Anna Rita Fetoni
- Department of Neuroscience, Reproductive Sciences and Dentistry-Audiology Section, University of Naples Federico II, 80131 Naples, Italy
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Willmore BDB, King AJ. Adaptation in auditory processing. Physiol Rev 2023; 103:1025-1058. [PMID: 36049112 PMCID: PMC9829473 DOI: 10.1152/physrev.00011.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Adaptation is an essential feature of auditory neurons, which reduces their responses to unchanging and recurring sounds and allows their response properties to be matched to the constantly changing statistics of sounds that reach the ears. As a consequence, processing in the auditory system highlights novel or unpredictable sounds and produces an efficient representation of the vast range of sounds that animals can perceive by continually adjusting the sensitivity and, to a lesser extent, the tuning properties of neurons to the most commonly encountered stimulus values. Together with attentional modulation, adaptation to sound statistics also helps to generate neural representations of sound that are tolerant to background noise and therefore plays a vital role in auditory scene analysis. In this review, we consider the diverse forms of adaptation that are found in the auditory system in terms of the processing levels at which they arise, the underlying neural mechanisms, and their impact on neural coding and perception. We also ask what the dynamics of adaptation, which can occur over multiple timescales, reveal about the statistical properties of the environment. Finally, we examine how adaptation to sound statistics is influenced by learning and experience and changes as a result of aging and hearing loss.
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Affiliation(s)
- Ben D. B. Willmore
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Andrew J. King
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
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33
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Brennan MA, Svec A, Farhadi A, Maxwell BN, Carney LH. Inherent envelope fluctuations in forward masking: Effects of age and hearing loss. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2023; 153:1994. [PMID: 37092921 PMCID: PMC10071988 DOI: 10.1121/10.0017724] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 03/10/2023] [Accepted: 03/13/2023] [Indexed: 05/03/2023]
Abstract
Forward masking is generally greater for Gaussian noise (GN) than for low-fluctuation noise maskers, i.e., GN disruption. Because the minimal hearing loss that is associated with older age may affect GN disruption differently than more significant hearing loss, the current study explored the contribution of minimal hearing loss associated with older age to GN disruption. GN disruption was measured using three masker-signal delays (25, 75, and 150 ms) for three adult groups: younger participants with normal hearing (NH), older participants with minimal hearing loss, and older participants with sensorineural hearing loss. The role of underlying mechanisms was tested using a computational model for midbrain neurons. The primary result suggests that older listeners with mild threshold elevations that typically occur with age may be more susceptible to the deleterious effects of masker envelope fluctuations than younger listeners with NH. Results from the computational model indicate that there may be a larger influence of efferent feedback and saturation of inner hair cells on forward masking and GN disruption than previously considered.
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Affiliation(s)
- Marc A Brennan
- University of Nebraska-Lincoln, Lincoln, Nebraska 68583, USA
| | - Adam Svec
- San José State University, San Jose, California 95192, USA
| | - Afagh Farhadi
- University of Rochester, Rochester, New York 14642, USA
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Regev J, Zaar J, Relaño-Iborra H, Dau T. Age-related reduction of amplitude modulation frequency selectivity. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2023; 153:2298. [PMID: 37092934 DOI: 10.1121/10.0017835] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Accepted: 03/27/2023] [Indexed: 05/03/2023]
Abstract
The perception of amplitude modulations (AMs) has been characterized by a frequency-selective process in the temporal envelope domain and simulated in computational auditory processing and perception models using a modulation filterbank. Such AM frequency-selective processing has been argued to be critical for the perception of complex sounds, including speech. This study aimed at investigating the effects of age on behavioral AM frequency selectivity in young (n = 11, 22-29 years) versus older (n = 10, 57-77 years) listeners with normal hearing, using a simultaneous AM masking paradigm with a sinusoidal carrier (2.8 kHz), target modulation frequencies of 4, 16, 64, and 128 Hz, and narrowband-noise modulation maskers. A reduction of AM frequency selectivity by a factor of up to 2 was found in the older listeners. While the observed AM selectivity co-varied with the unmasked AM detection sensitivity, the age-related broadening of the masked threshold patterns remained stable even when AM sensitivity was similar across groups for an extended stimulus duration. The results from the present study might provide a valuable basis for further investigations exploring the effects of age and reduced AM frequency selectivity on complex sound perception as well as the interaction of age and hearing impairment on AM processing and perception.
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Affiliation(s)
- Jonathan Regev
- Hearing Systems Section, Department of Health Technology, Technical University of Denmark, Kongens Lyngby, 2800, Denmark
| | - Johannes Zaar
- Eriksholm Research Centre, Snekkersten, 3070, Denmark
| | - Helia Relaño-Iborra
- Hearing Systems Section, Department of Health Technology, Technical University of Denmark, Kongens Lyngby, 2800, Denmark
| | - Torsten Dau
- Hearing Systems Section, Department of Health Technology, Technical University of Denmark, Kongens Lyngby, 2800, Denmark
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Shehabi AM, Prendergast G, Guest H, Plack CJ. Noise Exposure in Palestinian Workers Without a Diagnosis of Hearing Impairment: Relations to Speech-Perception-in-Noise Difficulties, Tinnitus, and Hyperacusis. JOURNAL OF SPEECH, LANGUAGE, AND HEARING RESEARCH : JSLHR 2023; 66:1085-1109. [PMID: 36802819 DOI: 10.1044/2022_jslhr-22-00461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
PURPOSE Many workers in developing countries are exposed to unsafe occupational noise due to inadequate health and safety practices. We tested the hypotheses that occupational noise exposure and aging affect speech-perception-in-noise (SPiN) thresholds, self-reported hearing ability, tinnitus presence, and hyperacusis severity among Palestinian workers. METHOD Palestinian workers (N = 251, aged 18-70 years) without diagnosed hearing or memory impairments completed online instruments including a noise exposure questionnaire; forward and backward digit span tests; hyperacusis questionnaire; the short-form Speech, Spatial and Qualities of Hearing Scale (SSQ12); the Tinnitus Handicap Inventory; and a digits-in-noise (DIN) test. Hypotheses were tested via multiple linear and logistic regression models, including age and occupational noise exposure as predictors, and with sex, recreational noise exposure, cognitive ability, and academic attainment as covariates. Familywise error rate was controlled across all 16 comparisons using the Bonferroni-Holm method. Exploratory analyses evaluated effects on tinnitus handicap. A comprehensive study protocol was preregistered. RESULTS Nonsignificant trends of poorer SPiN performance, poorer self-reported hearing ability, greater prevalence of tinnitus, greater tinnitus handicap, and greater severity of hyperacusis as a function of higher occupational noise exposure were observed. Greater hyperacusis severity was significantly predicted by higher occupational noise exposure. Aging was significantly associated with higher DIN thresholds and lower SSQ12 scores, but not with tinnitus presence, tinnitus handicap, or hyperacusis severity. CONCLUSIONS Workers in Palestine may suffer from auditory effects of occupational noise and aging despite no formal diagnosis. These findings highlight the importance of occupational noise monitoring and hearing-related health and safety practices in developing countries. SUPPLEMENTAL MATERIAL https://doi.org/10.23641/asha.22056701.
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Affiliation(s)
- Adnan M Shehabi
- Manchester Centre for Audiology and Deafness, The University of Manchester, United Kingdom
- Department of Audiology and Speech Therapy, Birzeit University, Palestine
| | - Garreth Prendergast
- Manchester Centre for Audiology and Deafness, The University of Manchester, United Kingdom
| | - Hannah Guest
- Manchester Centre for Audiology and Deafness, The University of Manchester, United Kingdom
| | - Christopher J Plack
- Manchester Centre for Audiology and Deafness, The University of Manchester, United Kingdom
- Department of Psychology, Lancaster University, United Kingdom
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Paciello F, Pisani A, Rinaudo M, Cocco S, Paludetti G, Fetoni AR, Grassi C. Noise-induced auditory damage affects hippocampus causing memory deficits in a model of early age-related hearing loss. Neurobiol Dis 2023; 178:106024. [PMID: 36724860 DOI: 10.1016/j.nbd.2023.106024] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 01/26/2023] [Accepted: 01/27/2023] [Indexed: 01/30/2023] Open
Abstract
Several studies identified noise-induced hearing loss (NIHL) as a risk factor for sensory aging and cognitive decline processes, including neurodegenerative diseases, such as dementia and age-related hearing loss (ARHL). Although the association between noise- and age-induced hearing impairment has been widely documented by epidemiological and experimental studies, the molecular mechanisms underlying this association are not fully understood as it is not known how these risk factors (aging and noise) can interact, affecting memory processes. We recently found that early noise exposure in an established animal model of ARHL (C57BL/6 mice) accelerates the onset of age-related cochlear dysfunctions. Here, we extended our previous data by investigating what happens in central brain structures (auditory cortex and hippocampus), to assess the relationship between hearing and memory impairment and the possible combined effect of noise and sensory aging on the cognitive domain. To this aim, we exposed juvenile C57BL/6 mice of 2 months of age to repeated noise sessions (60 min/day, pure tone of 100 dB SPL, 10 kHz, 10 consecutive days) and we monitored auditory threshold by measuring auditory brainstem responses (ABR), spatial working memory, by using the Y-maze test, and basal synaptic transmission by using ex vivo electrophysiological recordings, at different time points (1, 4 and 7 months after the onset of noise exposure, corresponding to 3, 6 and 9 months of age). We found that hearing loss, along with accelerated presbycusis onset, can induce persistent synaptic alterations in the auditory cortex. This was associated with decreased memory performance and oxidative-inflammatory injury in the hippocampus, the extra-auditory structure involved in memory processes. Collectively, our data confirm the critical relationship between auditory and memory circuits, suggesting that the combined detrimental effect of noise and sensory aging on hearing function can be considered a high-risk factor for both sensory and cognitive degenerative processes, given that early noise exposure accelerates presbycusis phenotype and induces hippocampal-dependent memory dysfunctions.
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Affiliation(s)
- Fabiola Paciello
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Roma, Italy; Department of Neuroscience, Università Cattolica del Sacro Cuore, 00168 Roma, Italy
| | - Anna Pisani
- Department of Head and Neck Surgery, Università Cattolica del Sacro Cuore, Roma, Italy
| | - Marco Rinaudo
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Roma, Italy; Department of Neuroscience, Università Cattolica del Sacro Cuore, 00168 Roma, Italy
| | - Sara Cocco
- Department of Neuroscience, Università Cattolica del Sacro Cuore, 00168 Roma, Italy
| | - Gaetano Paludetti
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Roma, Italy; Department of Head and Neck Surgery, Università Cattolica del Sacro Cuore, Roma, Italy
| | - Anna Rita Fetoni
- Department of Head and Neck Surgery, Università Cattolica del Sacro Cuore, Roma, Italy; Department of Neuroscience, Unit of Audiology, Università degli Studi di Napoli Federico II, Naples, Italy.
| | - Claudio Grassi
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Roma, Italy; Department of Neuroscience, Università Cattolica del Sacro Cuore, 00168 Roma, Italy
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Li N, Ma W, Ren F, Li X, Li F, Zong W, Wu L, Dai Z, Hui SCN, Edden RAE, Li M, Gao F. Neurochemical and functional reorganization of the cognitive-ear link underlies cognitive impairment in presbycusis. Neuroimage 2023; 268:119861. [PMID: 36610677 PMCID: PMC10026366 DOI: 10.1016/j.neuroimage.2023.119861] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2022] [Revised: 12/11/2022] [Accepted: 01/03/2023] [Indexed: 01/06/2023] Open
Abstract
Recent studies suggest that the interaction between presbycusis and cognitive impairment may be partially explained by the cognitive-ear link. However, the underlying neurophysiological mechanisms remain largely unknown. In this study, we combined magnetic resonance spectroscopy (MRS) and resting-state functional magnetic resonance imaging (fMRI) to investigate auditory gamma-aminobutyric acid (GABA) and glutamate (Glu) levels, intra- and inter-network functional connectivity, and their relationships with auditory and cognitive function in 51 presbycusis patients and 51 well-matched healthy controls. Our results confirmed reorganization of the cognitive-ear link in presbycusis, including decreased auditory GABA and Glu levels and aberrant functional connectivity involving auditory networks (AN) and cognitive-related networks, which were associated with reduced speech perception or cognitive impairment. Moreover, mediation analyses revealed that decreased auditory GABA levels and dysconnectivity between the AN and default mode network (DMN) mediated the association between hearing loss and impaired information processing speed in presbycusis. These findings highlight the importance of AN-DMN dysconnectivity in cognitive-ear link reorganization leading to cognitive impairment, and hearing loss may drive reorganization via decreased auditory GABA levels. Modulation of GABA neurotransmission may lead to new treatment strategies for cognitive impairment in presbycusis patients.
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Affiliation(s)
- Ning Li
- Department of Radiology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
| | - Wen Ma
- Department of Otolaryngology, the Central Hospital of Jinan City, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Fuxin Ren
- Department of Radiology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China; Department of Radiology, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Xiao Li
- Department of Radiology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China; Department of Radiology, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Fuyan Li
- Department of Radiology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China; Department of Radiology, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Wei Zong
- Department of Radiology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China; Department of Radiology, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Lili Wu
- CAS Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
| | - Zongrui Dai
- Westa College, Southwest University, Chongqing, China
| | - Steve C N Hui
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, USA; F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA
| | - Richard A E Edden
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, USA; F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA
| | - Muwei Li
- Vanderbilt University Institute of Imaging Science, Nashville, TN, USA
| | - Fei Gao
- Department of Radiology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China.
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38
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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: 2] [Impact Index Per Article: 2.0] [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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39
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Uzay B, Houcek A, Ma ZZ, Konradi C, Monteggia LM, Kavalali ET. Neurotransmitter release progressively desynchronizes in induced human neurons during synapse maturation and aging. Cell Rep 2023; 42:112042. [PMID: 36701235 PMCID: PMC10366341 DOI: 10.1016/j.celrep.2023.112042] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 11/04/2022] [Accepted: 01/13/2023] [Indexed: 01/26/2023] Open
Abstract
Rapid release of neurotransmitters in synchrony with action potentials is considered a key hardwired property of synapses. Here, in glutamatergic synapses formed between induced human neurons, we show that action potential-dependent neurotransmitter release becomes progressively desynchronized as synapses mature and age. In this solely excitatory network, the emergence of NMDAR-mediated transmission elicits endoplasmic reticulum (ER) stress leading to downregulation of key presynaptic molecules, synaptotagmin-1 and cysteine string protein α, that synchronize neurotransmitter release. The emergence of asynchronous release with neuronal maturity and subsequent aging is maintained by the high-affinity Ca2+ sensor synaptotagmin-7 and suppressed by the introduction of GABAergic transmission into the network, inhibition of NMDARs, and ER stress. These results suggest that long-term disruption of excitation-inhibition balance affects the synchrony of excitatory neurotransmission in human synapses.
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Affiliation(s)
- Burak Uzay
- Brain Institute, Vanderbilt University, Nashville, TN 37240-7933, USA; Department of Pharmacology, Vanderbilt University, 7130A MRB III 465 21st Avenue South, Nashville, TN 37240-7933, USA
| | - Aiden Houcek
- Brain Institute, Vanderbilt University, Nashville, TN 37240-7933, USA; Department of Pharmacology, Vanderbilt University, 7130A MRB III 465 21st Avenue South, Nashville, TN 37240-7933, USA
| | - Z Zack Ma
- Brain Institute, Vanderbilt University, Nashville, TN 37240-7933, USA; Department of Pharmacology, Vanderbilt University, 7130A MRB III 465 21st Avenue South, Nashville, TN 37240-7933, USA
| | - Christine Konradi
- Brain Institute, Vanderbilt University, Nashville, TN 37240-7933, USA; Department of Pharmacology, Vanderbilt University, 7130A MRB III 465 21st Avenue South, Nashville, TN 37240-7933, USA
| | - Lisa M Monteggia
- Brain Institute, Vanderbilt University, Nashville, TN 37240-7933, USA; Department of Pharmacology, Vanderbilt University, 7130A MRB III 465 21st Avenue South, Nashville, TN 37240-7933, USA
| | - Ege T Kavalali
- Brain Institute, Vanderbilt University, Nashville, TN 37240-7933, USA; Department of Pharmacology, Vanderbilt University, 7130A MRB III 465 21st Avenue South, Nashville, TN 37240-7933, USA.
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40
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Herrmann B, Maess B, Johnsrude IS. Sustained responses and neural synchronization to amplitude and frequency modulation in sound change with age. Hear Res 2023; 428:108677. [PMID: 36580732 DOI: 10.1016/j.heares.2022.108677] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 12/09/2022] [Accepted: 12/16/2022] [Indexed: 12/23/2022]
Abstract
Perception of speech requires sensitivity to features, such as amplitude and frequency modulations, that are often temporally regular. Previous work suggests age-related changes in neural responses to temporally regular features, but little work has focused on age differences for different types of modulations. We recorded magnetoencephalography in younger (21-33 years) and older adults (53-73 years) to investigate age differences in neural responses to slow (2-6 Hz sinusoidal and non-sinusoidal) modulations in amplitude, frequency, or combined amplitude and frequency. Audiometric pure-tone average thresholds were elevated in older compared to younger adults, indicating subclinical hearing impairment in the recruited older-adult sample. Neural responses to sound onset (independent of temporal modulations) were increased in magnitude in older compared to younger adults, suggesting hyperresponsivity and a loss of inhibition in the aged auditory system. Analyses of neural activity to modulations revealed greater neural synchronization with amplitude, frequency, and combined amplitude-frequency modulations for older compared to younger adults. This potentiated response generalized across different degrees of temporal regularity (sinusoidal and non-sinusoidal), although neural synchronization was generally lower for non-sinusoidal modulation. Despite greater synchronization, sustained neural activity was reduced in older compared to younger adults for sounds modulated both sinusoidally and non-sinusoidally in frequency. Our results suggest age differences in the sensitivity of the auditory system to features present in speech and other natural sounds.
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Affiliation(s)
- Björn Herrmann
- Rotman Research Institute, Baycrest, North York, ON M6A 2E1, Canada; Department of Psychology, University of Toronto, Toronto, ON M5S 1A1, Canada; Department of Psychology & Brain and Mind Institute, The University of Western Ontario, London, ON N6A 3K7, Canada.
| | - Burkhard Maess
- Max Planck Institute for Human Cognitive and Brain Sciences, Brain Networks Unit, Leipzig 04103, Germany
| | - Ingrid S Johnsrude
- Department of Psychology & Brain and Mind Institute, The University of Western Ontario, London, ON N6A 3K7, Canada; School of Communication Sciences & Disorders, The University of Western Ontario, London, ON N6A 5B7, Canada
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41
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Paciello F, Ripoli C, Fetoni AR, Grassi C. Redox Imbalance as a Common Pathogenic Factor Linking Hearing Loss and Cognitive Decline. Antioxidants (Basel) 2023; 12:antiox12020332. [PMID: 36829891 PMCID: PMC9952092 DOI: 10.3390/antiox12020332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 01/23/2023] [Accepted: 01/29/2023] [Indexed: 02/04/2023] Open
Abstract
Experimental and clinical data suggest a tight link between hearing and cognitive functions under both physiological and pathological conditions. Indeed, hearing perception requires high-level cognitive processes, and its alterations have been considered a risk factor for cognitive decline. Thus, identifying common pathogenic determinants of hearing loss and neurodegenerative disease is challenging. Here, we focused on redox status imbalance as a possible common pathological mechanism linking hearing and cognitive dysfunctions. Oxidative stress plays a critical role in cochlear damage occurring during aging, as well as in that induced by exogenous factors, including noise. At the same time, increased oxidative stress in medio-temporal brain regions, including the hippocampus, is a hallmark of neurodegenerative disorders like Alzheimer's disease. As such, antioxidant therapy seems to be a promising approach to prevent and/or counteract both sensory and cognitive neurodegeneration. Here, we review experimental evidence suggesting that redox imbalance is a key pathogenetic factor underlying the association between sensorineural hearing loss and neurodegenerative diseases. A greater understanding of the pathophysiological mechanisms shared by these two diseased conditions will hopefully provide relevant information to develop innovative and effective therapeutic strategies.
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Affiliation(s)
- Fabiola Paciello
- Department of Neuroscience, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy
| | - Cristian Ripoli
- Department of Neuroscience, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy
- Correspondence: ; Tel.: +39-0630154966
| | - Anna Rita Fetoni
- Unit of Audiology, Department of Neuroscience, Università degli Studi di Napoli Federico II, 80138 Naples, Italy
| | - Claudio Grassi
- Department of Neuroscience, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy
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42
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Eddins AC, Ozmeral EJ, Eddins DA. Aging alters across-hemisphere cortical dynamics during binaural temporal processing. Front Neurosci 2023; 16:1060172. [PMID: 36703999 PMCID: PMC9871896 DOI: 10.3389/fnins.2022.1060172] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Accepted: 12/16/2022] [Indexed: 01/11/2023] Open
Abstract
Differences in the timing and intensity of sounds arriving at the two ears provide fundamental binaural cues that help us localize and segregate sounds in the environment. Neural encoding of these cues is commonly represented asymmetrically in the cortex with stronger activation in the hemisphere contralateral to the perceived spatial location. Although advancing age is known to degrade the perception of binaural cues, less is known about how the neural representation of such cues is impacted by age. Here, we use electroencephalography (EEG) to investigate age-related changes in the hemispheric distribution of interaural time difference (ITD) encoding based on cortical auditory evoked potentials (CAEPs) and derived binaural interaction component (BIC) measures in ten younger and ten older normal-hearing adults. Sensor-level analyses of the CAEP and BIC showed age-related differences in global field power, where older listeners had significantly larger responses than younger for both binaural metrics. Source-level analyses showed hemispheric differences in auditory cortex activity for left and right lateralized stimuli in younger adults, consistent with a contralateral activation model for processing ITDs. Older adults, however, showed reduced hemispheric asymmetry across ITDs, despite having overall larger responses than younger adults. Further, when averaged across ITD condition to evaluate changes in cortical asymmetry over time, there was a significant shift in laterality corresponding to the peak components (P1, N1, P2) in the source waveform that also was affected by age. These novel results demonstrate across-hemisphere cortical dynamics during binaural temporal processing that are altered with advancing age.
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Affiliation(s)
- Ann Clock Eddins
- Department of Communication Sciences and Disorders, University of South Florida, Tampa, FL, United States
- School of Communication Sciences and Disorders, University of Central Florida, Orlando, FL, United States
| | - Erol J. Ozmeral
- Department of Communication Sciences and Disorders, University of South Florida, Tampa, FL, United States
| | - David A. Eddins
- Department of Communication Sciences and Disorders, University of South Florida, Tampa, FL, United States
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Gómez-Álvarez M, Johannesen PT, Coelho-de-Sousa SL, Klump GM, Lopez-Poveda EA. The Relative Contribution of Cochlear Synaptopathy and Reduced Inhibition to Age-Related Hearing Impairment for People With Normal Audiograms. Trends Hear 2023; 27:23312165231213191. [PMID: 37956654 PMCID: PMC10644751 DOI: 10.1177/23312165231213191] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 10/18/2023] [Accepted: 10/23/2023] [Indexed: 11/15/2023] Open
Abstract
Older people often show auditory temporal processing deficits and speech-in-noise intelligibility difficulties even when their audiogram is clinically normal. The causes of such problems remain unclear. Some studies have suggested that for people with normal audiograms, age-related hearing impairments may be due to a cognitive decline, while others have suggested that they may be caused by cochlear synaptopathy. Here, we explore an alternative hypothesis, namely that age-related hearing deficits are associated with decreased inhibition. For human adults (N = 30) selected to cover a reasonably wide age range (25-59 years), with normal audiograms and normal cognitive function, we measured speech reception thresholds in noise (SRTNs) for disyllabic words, gap detection thresholds (GDTs), and frequency modulation detection thresholds (FMDTs). We also measured the rate of growth (slope) of auditory brainstem response wave-I amplitude with increasing level as an indirect indicator of cochlear synaptopathy, and the interference inhibition score in the Stroop color and word test (SCWT) as a proxy for inhibition. As expected, performance in the auditory tasks worsened (SRTNs, GDTs, and FMDTs increased), and wave-I slope and SCWT inhibition scores decreased with ageing. Importantly, SRTNs, GDTs, and FMDTs were not related to wave-I slope but worsened with decreasing SCWT inhibition. Furthermore, after partialling out the effect of SCWT inhibition, age was no longer related to SRTNs or GDTs and became less strongly related to FMDTs. Altogether, results suggest that for people with normal audiograms, age-related deficits in auditory temporal processing and speech-in-noise intelligibility are mediated by decreased inhibition rather than cochlear synaptopathy.
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Affiliation(s)
- Marcelo Gómez-Álvarez
- Instituto de Neurociencias de Castilla y León, Universidad de Salamanca, Salamanca, Spain
- Instituto de Investigación Biomédica de Salamanca, Universidad de Salamanca, Salamanca, Spain
| | - Peter T. Johannesen
- Instituto de Neurociencias de Castilla y León, Universidad de Salamanca, Salamanca, Spain
- Instituto de Investigación Biomédica de Salamanca, Universidad de Salamanca, Salamanca, Spain
| | - Sónia L. Coelho-de-Sousa
- Instituto de Neurociencias de Castilla y León, Universidad de Salamanca, Salamanca, Spain
- Instituto de Investigación Biomédica de Salamanca, Universidad de Salamanca, Salamanca, Spain
| | - Georg M. Klump
- Department of Neuroscience and Cluster of Excellence “Hearing4all”, Carl von Ossietzky University of Oldenburg, Oldenburg, Germany
| | - Enrique A. Lopez-Poveda
- Instituto de Neurociencias de Castilla y León, Universidad de Salamanca, Salamanca, Spain
- Instituto de Investigación Biomédica de Salamanca, Universidad de Salamanca, Salamanca, Spain
- Departamento de Cirugía, Facultad de Medicina, Universidad de Salamanca, Salamanca, Spain
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44
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Chequer Charan D, Hua Y, Wang H, Huang W, Wang F, Elgoyhen AB, Boergens KM, Di Guilmi MN. Volume electron microscopy reveals age-related circuit remodeling in the auditory brainstem. Front Cell Neurosci 2022; 16:1070438. [PMID: 36589288 PMCID: PMC9799098 DOI: 10.3389/fncel.2022.1070438] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Accepted: 11/21/2022] [Indexed: 12/23/2022] Open
Abstract
The medial nucleus of the trapezoid body (MNTB) is an integral component of the auditory brainstem circuitry involved in sound localization. The giant presynaptic nerve terminal with multiple active zones, the calyx of Held (CH), is a hallmark of this nucleus, which mediates fast and synchronized glutamatergic synaptic transmission. To delineate how these synaptic structures adapt to reduced auditory afferents due to aging, we acquired and reconstructed circuitry-level volumes of mouse MNTB at different ages (3 weeks, 6, 18, and 24 months) using serial block-face electron microscopy. We used C57BL/6J, the most widely inbred mouse strain used for transgenic lines, which displays a type of age-related hearing loss. We found that MNTB neurons reduce in density with age. Surprisingly we observed an average of approximately 10% of poly-innervated MNTB neurons along the mouse lifespan, with prevalence in the low frequency region. Moreover, a tonotopy-dependent heterogeneity in CH morphology was observed in young but not in older mice. In conclusion, our data support the notion that age-related hearing impairments can be in part a direct consequence of several structural alterations and circuit remodeling in the brainstem.
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Affiliation(s)
- Daniela Chequer Charan
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, Dr. Héctor N. Torres, INGEBI-CONICET, Buenos Aires, Argentina
| | - Yunfeng Hua
- Shanghai Institute of Precision Medicine, Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Haoyu Wang
- Shanghai Institute of Precision Medicine, Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Wenqing Huang
- Shanghai Institute of Precision Medicine, Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Fangfang Wang
- Shanghai Institute of Precision Medicine, Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Ana Belén Elgoyhen
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, Dr. Héctor N. Torres, INGEBI-CONICET, Buenos Aires, Argentina
| | - Kevin M. Boergens
- Department of Physics, The University of Illinois at Chicago, Chicago, IL, United States,*Correspondence: Kevin M. Boergens Mariano N. Di Guilmi
| | - Mariano N. Di Guilmi
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, Dr. Héctor N. Torres, INGEBI-CONICET, Buenos Aires, Argentina,*Correspondence: Kevin M. Boergens Mariano N. Di Guilmi
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45
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Shilling-Scrivo K, Mittelstadt J, Kanold PO. Decreased Modulation of Population Correlations in Auditory Cortex Is Associated with Decreased Auditory Detection Performance in Old Mice. J Neurosci 2022; 42:9278-9292. [PMID: 36302637 PMCID: PMC9761686 DOI: 10.1523/jneurosci.0955-22.2022] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 09/17/2022] [Accepted: 10/24/2022] [Indexed: 02/02/2023] Open
Abstract
Age-related hearing loss (presbycusis) affects one-third of the world's population. One hallmark of presbycusis is difficulty hearing in noisy environments. Presbycusis can be separated into two components: the aging ear and the aging brain. To date, the role of the aging brain in presbycusis is not well understood. Activity in the primary auditory cortex (A1) during a behavioral task is because of a combination of responses representing the acoustic stimuli, attentional gain, and behavioral choice. Disruptions in any of these aspects can lead to decreased auditory processing. To investigate how these distinct components are disrupted in aging, we performed in vivo 2-photon Ca2+ imaging in both male and female mice (Thy1-GCaMP6s × CBA/CaJ mice) that retain peripheral hearing into old age. We imaged A1 neurons of young adult (2-6 months) and old mice (16-24 months) during a tone detection task in broadband noise. While young mice performed well, old mice performed worse at low signal-to-noise ratios. Calcium imaging showed that old animals have increased prestimulus activity, reduced attentional gain, and increased noise correlations. Increased correlations in old animals exist regardless of cell tuning and behavioral outcome, and these correlated networks exist over a much larger portion of cortical space. Neural decoding techniques suggest that this prestimulus activity is predictive of old animals making early responses. Together, our results suggest a model in which old animals have higher and more correlated prestimulus activity and cannot fully suppress this activity, leading to the decreased representation of targets among distracting stimuli.SIGNIFICANCE STATEMENT Aging inhibits the ability to hear clearly in noisy environments. We show that the aging auditory cortex is unable to fully suppress its responses to background noise. During an auditory behavior, fewer neurons were suppressed in the old relative to young animals, which leads to higher prestimulus activity and more false alarms. We show that this excess activity additionally leads to increased correlations between neurons, reducing the amount of relevant stimulus information in the auditory cortex. Future work identifying the lost circuits that are responsible for proper background suppression could provide new targets for therapeutic strategies to preserve auditory processing ability into old age.
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Affiliation(s)
- Kelson Shilling-Scrivo
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland 21230
| | - Jonah Mittelstadt
- Department of Biology, University of Maryland, College Park, Maryland 20742
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland 20215
| | - Patrick O Kanold
- Department of Biology, University of Maryland, College Park, Maryland 20742
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland 20215
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46
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Mafi AM, Tokar N, Russ MG, Barat O, Mellott JG. Age-related ultrastructural changes in the lateral cortex of the inferior colliculus. Neurobiol Aging 2022; 120:43-59. [PMID: 36116395 PMCID: PMC10276896 DOI: 10.1016/j.neurobiolaging.2022.08.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 08/15/2022] [Accepted: 08/15/2022] [Indexed: 10/15/2022]
Abstract
Temporal precision, a key component of sound and speech processing in the inferior colliculus (IC), depends on a balance of inhibition and excitation, and this balance degrades during aging. The cause of disrupted excitatory-inhibitory balance in aging is unknown, however changes at the synapse are a likely candidate. We sought to determine whether synaptic changes occur in the lateral cortex of the IC (IClc), a multimodal nucleus that processes lemniscal, intrinsic, somatosensory, and descending auditory input. Using electron microscopic techniques across young, middle age and old Fisher Brown Norway rats, our results demonstrate minimal loss of synapses in middle age, but significant (∼28%) loss during old age. However, in middle age, targeting of GABAergic dendrites by GABAergic synapses is increased and the active zones of excitatory synapses (that predominantly target GABA-negative dendrites) are lengthened. These synaptic changes likely result in a net increase of excitation in the IClc during middle age. Thus, disruption of excitatory-inhibitory balance in the aging IClc may be due to synaptic changes that begin in middle age.
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Affiliation(s)
- Amir M Mafi
- The Ohio State College of Medicine, The Ohio State, Columbus, OH, USA
| | - Nick Tokar
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, OH, USA
| | - Matthew G Russ
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, OH, USA
| | - Oren Barat
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, OH, USA
| | - Jeffrey G Mellott
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, OH, USA.
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Sauvé SA, Marozeau J, Rich Zendel B. The effects of aging and musicianship on the use of auditory streaming cues. PLoS One 2022; 17:e0274631. [PMID: 36137151 PMCID: PMC9498935 DOI: 10.1371/journal.pone.0274631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Accepted: 08/31/2022] [Indexed: 11/22/2022] Open
Abstract
Auditory stream segregation, or separating sounds into their respective sources and tracking them over time, is a fundamental auditory ability. Previous research has separately explored the impacts of aging and musicianship on the ability to separate and follow auditory streams. The current study evaluated the simultaneous effects of age and musicianship on auditory streaming induced by three physical features: intensity, spectral envelope and temporal envelope. In the first study, older and younger musicians and non-musicians with normal hearing identified deviants in a four-note melody interleaved with distractors that were more or less similar to the melody in terms of intensity, spectral envelope and temporal envelope. In the second study, older and younger musicians and non-musicians participated in a dissimilarity rating paradigm with pairs of melodies that differed along the same three features. Results suggested that auditory streaming skills are maintained in older adults but that older adults rely on intensity more than younger adults while musicianship is associated with increased sensitivity to spectral and temporal envelope, acoustic features that are typically less effective for stream segregation, particularly in older adults.
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Affiliation(s)
- Sarah A. Sauvé
- Division of Community Health and Humanities, Faculty of Medicine, Memorial University of Newfoundland, St. John’s, Newfoundland and Labrador, Canada
- * E-mail:
| | - Jeremy Marozeau
- Department of Health Technology, Technical University of Denmark, Lyngby, Denmark
| | - Benjamin Rich Zendel
- Division of Community Health and Humanities, Faculty of Medicine, Memorial University of Newfoundland, St. John’s, Newfoundland and Labrador, Canada
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48
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Harris KC, Dias JW, McClaskey CM, Rumschlag J, Prisciandaro J, Dubno JR. Afferent Loss, GABA, and Central Gain in Older Adults: Associations with Speech Recognition in Noise. J Neurosci 2022; 42:7201-7212. [PMID: 35995564 PMCID: PMC9512571 DOI: 10.1523/jneurosci.0242-22.2022] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 07/20/2022] [Accepted: 08/14/2022] [Indexed: 11/21/2022] Open
Abstract
Deficits in auditory nerve (AN) function for older adults reduce afferent input to the cortex. The extent to which the cortex in older adults adapts to this loss of afferent input and the mechanisms underlying this adaptation are not well understood. We took a neural systems approach measuring AN and cortical evoked responses within 50 older and 27 younger human adults (59 female) to estimate central gain or increased cortical activity despite reduced AN activity. Relative to younger adults, older adults' AN response amplitudes were smaller, but cortical responses were not. We used the relationship between AN and cortical response amplitudes in younger adults to predict cortical response amplitudes for older adults from their AN responses. Central gain in older adults was thus defined as the difference between their observed cortical responses and those predicted from the parameter estimates of younger adults. In older adults, decreased afferent input contributed to lower cortical GABA levels, greater central gain, and poorer speech recognition in noise (SIN). These effects on SIN occur in addition to, and independent from, effects attributed to elevated hearing thresholds. Our results are consistent with animal models of central gain and suggest that reduced AN afferent input in some older adults may result in changes in cortical encoding and inhibitory neurotransmission, which contribute to reduced SIN. An advancement in our understanding of the changes that occur throughout the auditory system in response to the gradual loss of input with increasing age may provide potential therapeutic targets for intervention.SIGNIFICANCE STATEMENT Age-related hearing loss is one of the most common chronic conditions of aging, yet little is known about how the cortex adapts to this loss of sensory input. We measured AN and cortical responses to the same stimulus in younger and older adults. In older adults we found hyperexcitability in cortical activity relative to concomitant declines in afferent input that are consistent with central gain. Lower levels of cortical GABA, an inhibitory neurotransmitter, were associated with greater central gain, which predicted poorer SIN. The results suggest that the cortex in older adults may adapt to attenuated sensory input by reducing inhibition to amplify the cortical response, but this amplification may lead to poorer SIN.
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Affiliation(s)
| | - James W Dias
- Department of Otolaryngology-Head and Neck Surgery
| | | | | | - James Prisciandaro
- Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, South Carolina 29425-5500
| | - Judy R Dubno
- Department of Otolaryngology-Head and Neck Surgery
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49
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Kuruvilla-Mathew A, Thorne PR, Purdy SC. Effects of aging on neural processing during an active listening task. PLoS One 2022; 17:e0273304. [PMID: 36070253 PMCID: PMC9451064 DOI: 10.1371/journal.pone.0273304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 08/06/2022] [Indexed: 11/18/2022] Open
Abstract
Factors affecting successful listening in older adults and the corresponding electrophysiological signatures are not well understood. The present study investigated age-related differences in attention and temporal processing, as well as differences in the neural activity related to signal degradation during a number comparison task. Participants listened to digits presented in background babble and were tested at two levels of signal clarity, clear and degraded. Behavioral and electrophysiological measures were examined in 30 older and 20 younger neurologically-healthy adults. Relationships between performance on the number comparison task, behavioral measures, and neural activity were used to determine correlates of listening deficits associated with aging. While older participants showed poorer performance overall on all behavioral measures, their scores on the number comparison task were largely predicted (based on regression analyses) by their sensitivity to temporal fine structure cues. Compared to younger participants, older participants required higher signal-to-noise ratios (SNRs) to achieve equivalent performance on the number comparison task. With increasing listening demands, age-related changes were observed in neural processing represented by the early-N1 and later-P3 time windows. Source localization analyses revealed age differences in source activity for the degraded listening condition that was located in the left prefrontal cortex. In addition, this source activity negatively correlated with task performance in the older group. Together, these results suggest that older adults exhibit reallocation of processing resources to complete a demanding listening task. However, this effect was evident only for poorer performing older adults who showed greater posterior to anterior shift in P3 response amplitudes than older adults who were good performers and younger adults. These findings might reflect less efficient recruitment of neural resources that is associated with aging during effortful listening performance.
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Affiliation(s)
- Abin Kuruvilla-Mathew
- Speech Science, School of Psychology, University of Auckland, Auckland, New Zealand
- Eisdell Moore Centre, University of Auckland, Auckland, New Zealand
- * E-mail:
| | - Peter R. Thorne
- Eisdell Moore Centre, University of Auckland, Auckland, New Zealand
- Faculty of Medical and Health Science, University of Auckland, Auckland, New Zealand
- Brain Research New Zealand, University of Auckland, Auckland, New Zealand
| | - Suzanne C. Purdy
- Speech Science, School of Psychology, University of Auckland, Auckland, New Zealand
- Eisdell Moore Centre, University of Auckland, Auckland, New Zealand
- Brain Research New Zealand, University of Auckland, Auckland, New Zealand
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50
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Bazard P, Pineros J, Acosta AA, Thivierge M, Paganella LR, Zucker S, Mannering FL, Modukuri S, Zhu X, Frisina RD, Ding B. Post-Translational Modifications and Age-related Hearing Loss. Hear Res 2022; 426:108625. [DOI: 10.1016/j.heares.2022.108625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Revised: 08/21/2022] [Accepted: 09/23/2022] [Indexed: 11/04/2022]
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