1
|
Inguscio BMS, Cartocci G, Sciaraffa N, Nicastri M, Giallini I, Greco A, Babiloni F, Mancini P. Gamma-Band Modulation in Parietal Area as the Electroencephalographic Signature for Performance in Auditory-Verbal Working Memory: An Exploratory Pilot Study in Hearing and Unilateral Cochlear Implant Children. Brain Sci 2022; 12:1291. [PMID: 36291225 PMCID: PMC9599211 DOI: 10.3390/brainsci12101291] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Revised: 09/20/2022] [Accepted: 09/21/2022] [Indexed: 07/30/2023] Open
Abstract
This pilot study investigates the neurophysiological patterns of visual and auditory verbal working memory (VWM) in unilateral cochlear implant users (UCIs). We compared the task-related electroencephalogram (EEG) power spectral density of 7- to 13-year-old UCIs (n = 7) with a hearing control group (HC, n = 10) during the execution of a three-level n-back task with auditory and visual verbal (letters) stimuli. Performances improved as memory load decreased regardless of sensory modality (SM) and group factors. Theta EEG activation over the frontal area was proportionally influenced by task level; the left hemisphere (LH) showed greater activation in the gamma band, suggesting lateralization of VWM function regardless of SM. However, HCs showed stronger activation patterns in the LH than UCIs regardless of SM and in the parietal area (PA) during the most challenging audio condition. Linear regressions for gamma activation in the PA suggest the presence of a pattern-supporting auditory VWM only in HCs. Our findings seem to recognize gamma activation in the PA as the signature of effective auditory VWM. These results, although preliminary, highlight this EEG pattern as a possible cause of the variability found in VWM outcomes in deaf children, opening up new possibilities for interdisciplinary research and rehabilitation intervention.
Collapse
Affiliation(s)
- Bianca Maria Serena Inguscio
- Department of Sense Organs, Sapienza University of Rome, Viale dell’Università 31, 00161 Rome, Italy
- BrainSigns Srl, Lungotevere Michelangelo, 9, 00192 Rome, Italy
- Department of Human Neuroscience, Sapienza University of Rome, Viale dell’Università 30, 00161 Rome, Italy
| | - Giulia Cartocci
- BrainSigns Srl, Lungotevere Michelangelo, 9, 00192 Rome, Italy
- Department of Molecular Medicine, Sapienza University of Rome, Viale Regina Elena 291, 00161 Rome, Italy
| | | | - Maria Nicastri
- Department of Sense Organs, Sapienza University of Rome, Viale dell’Università 31, 00161 Rome, Italy
| | - Ilaria Giallini
- Department of Sense Organs, Sapienza University of Rome, Viale dell’Università 31, 00161 Rome, Italy
| | - Antonio Greco
- Department of Sense Organs, Sapienza University of Rome, Viale dell’Università 31, 00161 Rome, Italy
| | - Fabio Babiloni
- BrainSigns Srl, Lungotevere Michelangelo, 9, 00192 Rome, Italy
- Department of Molecular Medicine, Sapienza University of Rome, Viale Regina Elena 291, 00161 Rome, Italy
- Department of Computer Science, Hangzhou Dianzi University, Xiasha Higher Education Zone, Hangzhou 310018, China
| | - Patrizia Mancini
- Department of Sense Organs, Sapienza University of Rome, Viale dell’Università 31, 00161 Rome, Italy
| |
Collapse
|
2
|
Arnavut E, Hamilton J, Yao R, Sajjad M, Hadjiargyrou M, Komatsu D, Thanos PK. Abstinence following intermittent methylphenidate exposure dose-dependently modifies brain glucose metabolism in the rat brain. Synapse 2022; 76:17-30. [PMID: 35730134 DOI: 10.1002/syn.22243] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2022] [Revised: 06/01/2022] [Accepted: 06/12/2022] [Indexed: 11/10/2022]
Abstract
Methylphenidate (MP) is a psychostimulant chronically prescribed for the treatment of attention deficit hyperactivity disorder (ADHD). Additionally, MP users may take breaks from using the medication during "drug holidays," which may include short-term or long-term breaks from medication. The present study utilized fluorodeoxyglucose (FDG) positron emission tomography (PET) to analyze the effects of chronic oral MP use and abstinence on brain glucose metabolism (BGluM) in rats at two different doses: high dose (HD) and low dose (LD). The schedule of treatment was 3 weeks on-treatment and 1 week off-treatment for a period of 13 weeks, followed by an abstinence period of 4 total weeks. Results showed that chronic MP treatment using this schedule did not lead to significant changes in BGluM when comparing the control to HD MP groups. However, significant activation in BGluM was observed after periods of abstinence between control and HD MP rats in the following brain regions: the trigeminal nucleus, reticular nucleus, inferior olive, lemniscus, mesencephalic reticular formation, inferior colliculus, and several areas of the cerebellum. These brain regions and functional brain circuit play a role in facial sensory function, the auditory pathway, organizing connections between the thalamus and cortex, motor learning, auditory function, control over eye movement, auditory information integration, and both motor and cognitive functions. These results, when considered with previous studies, indicate that MP schedule of use may have differing effects on BGluM. BGluM following long-term MP use was dependent on MP dose and schedule of use in rats. This study was conducted in non-ADHD model rats with the aim to establish an understanding of the effects of MP itself, especially given the growing chronic off-label and prescribed use of MP. Further studies are needed for analysis of the drug's effects on an ADHD model.
Collapse
Affiliation(s)
- Eliz Arnavut
- Behavioral Neuropharmacology and Neuroimaging Laboratory on Addictions (BNNLA), Department of Pharmacology and Toxicology, Clinical Research Institute on Addictions, Jacobs School of Medicine and Biomedical Sciences, State University at Buffalo, Buffalo, New York
| | - John Hamilton
- Behavioral Neuropharmacology and Neuroimaging Laboratory on Addictions (BNNLA), Department of Pharmacology and Toxicology, Clinical Research Institute on Addictions, Jacobs School of Medicine and Biomedical Sciences, State University at Buffalo, Buffalo, New York
| | - Rutao Yao
- Department of Nuclear Medicine, State University of New York at Buffalo, Buffalo, New York, USA
| | - Munawwar Sajjad
- Department of Nuclear Medicine, State University of New York at Buffalo, Buffalo, New York, USA
| | - Michael Hadjiargyrou
- Department of Biological and Chemical Sciences, New York Institute of Technology, Old Westbury, New York, USA
| | - David Komatsu
- Department of Orthopedics, Stony Brook University, Stony Brook, New York, USA
| | - Panayotis K Thanos
- Behavioral Neuropharmacology and Neuroimaging Laboratory on Addictions (BNNLA), Department of Pharmacology and Toxicology, Clinical Research Institute on Addictions, Jacobs School of Medicine and Biomedical Sciences, State University at Buffalo, Buffalo, New York.,Department of Psychology, State University at Buffalo, Buffalo, New York, USA
| |
Collapse
|
3
|
Gonzalez JE, Musiek FE. The Onset-Offset N1-P2 Cortical Auditory Evoked Response in Individuals With High-Frequency Sensorineural Hearing Loss: Responses to High- and Low-Frequency Narrowband Noise. Am J Audiol 2022; 31:359-369. [PMID: 35436425 DOI: 10.1044/2022_aja-21-00124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
PURPOSE This study aimed to determine whether onset-offset N1-P2 auditory evoked responses differ in amplitude, latency, and offset-to-onset trough-to-peak N1-P2 amplitude ratios (OOAR) between normal hearing (NH) sensitivity and moderate high-frequency sensorineural hearing loss (HFSNHL) groups when stimuli target regions of peripheral hearing sensitivity where the groups are in the normal range (i.e., 500 Hz) versus where they differ regarding presence of hearing loss (i.e., 4000 Hz). METHOD Onset-offset N1-P2 auditory evoked responses were measured from 10 participants with normal hearing sensitivity and seven participants with moderate HFSNHL using 500-Hz and 4000-Hz narrowband noise (NBN) stimuli. Stimuli were 2000 ms with 40-ms rise-fall times presented at 50 dB SL referenced to stimulus behavioral thresholds. Amplitudes and latencies were analyzed for N1 and P2 onset and offset components via repeated measures analysis of variance (ANOVA). OOARs were compared between groups using one-way ANOVA and across stimuli per group using paired samples t tests. RESULTS Despite dB SPL stimulus presentation differences between groups, there were no significant differences in individual/absolute amplitude and latency waveform components between groups for either stimulus. Derived comparative calculations of OOAR for 4000-Hz NBN were significantly larger (p < .025; NH: .39; HFSNHL: .62) for the group with HFSNHL than the group with NH sensitivity; 500-Hz NBN OOAR did not reach significance. OOARs revealed no significant difference between stimuli for the group with normal hearing sensitivity, with .38 OOAR for both stimuli (p = .961). OOAR comparisons for the HFSNHL group across stimuli were significant (p = .012), with the 4000-Hz NBN OOAR being nearly double the size of the 500-Hz NBN OOAR. CONCLUSIONS OOARs may provide insight to the balance of excitatory and inhibitory neural firing in the central auditory nervous system (CANS). Larger OOARs may be a biomarker of reduced CANS inhibition, perhaps indicative of a homeostatic central auditory gain mechanism.
Collapse
Affiliation(s)
- Jennifer E. Gonzalez
- Department of Otolaryngology—Head and Neck Surgery, Division of Audiology, Mayo Clinic in Arizona, Scottsdale
| | - Frank E. Musiek
- Department of Speech, Language, and Hearing Sciences, The University of Arizona, Tucson
| |
Collapse
|
4
|
Singh K, Cauzzo S, García-Gomar MG, Stauder M, Vanello N, Passino C, Bianciardi M. Functional connectome of arousal and motor brainstem nuclei in living humans by 7 Tesla resting-state fMRI. Neuroimage 2022; 249:118865. [PMID: 35031472 DOI: 10.1016/j.neuroimage.2021.118865] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 11/30/2021] [Accepted: 12/27/2021] [Indexed: 01/21/2023] Open
Abstract
Brainstem nuclei play a pivotal role in many functions, such as arousal and motor control. Nevertheless, the connectivity of arousal and motor brainstem nuclei is understudied in living humans due to the limited sensitivity and spatial resolution of conventional imaging, and to the lack of atlases of these deep tiny regions of the brain. For a holistic comprehension of sleep, arousal and associated motor processes, we investigated in 20 healthy subjects the resting-state functional connectivity of 18 arousal and motor brainstem nuclei in living humans. To do so, we used high spatial-resolution 7 Tesla resting-state fMRI, as well as a recently developed in-vivo probabilistic atlas of these nuclei in stereotactic space. Further, we verified the translatability of our brainstem connectome approach to conventional (e.g. 3 Tesla) fMRI. Arousal brainstem nuclei displayed high interconnectivity, as well as connectivity to the thalamus, hypothalamus, basal forebrain and frontal cortex, in line with animal studies and as expected for arousal regions. Motor brainstem nuclei showed expected connectivity to the cerebellum, basal ganglia and motor cortex, as well as high interconnectivity. Comparison of 3 Tesla to 7 Tesla connectivity results indicated good translatability of our brainstem connectome approach to conventional fMRI, especially for cortical and subcortical (non-brainstem) targets and to a lesser extent for brainstem targets. The functional connectome of 18 arousal and motor brainstem nuclei with the rest of the brain might provide a better understanding of arousal, sleep and accompanying motor function in living humans in health and disease.
Collapse
Affiliation(s)
- Kavita Singh
- Brainstem Imaging Laboratory, Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States.
| | - Simone Cauzzo
- Brainstem Imaging Laboratory, Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States; Institute of Life Sciences, Sant'Anna School of Advanced Studies, Pisa, Italy
| | - María Guadalupe García-Gomar
- Brainstem Imaging Laboratory, Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States
| | - Matthew Stauder
- Brainstem Imaging Laboratory, Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States
| | - Nicola Vanello
- Dipartimento di Ingegneria dell'Informazione, University of Pisa, Pisa, Italy
| | - Claudio Passino
- Institute of Life Sciences, Sant'Anna School of Advanced Studies, Pisa, Italy; Fondazione Toscana Gabriele Monasterio, Pisa, Italy
| | - Marta Bianciardi
- Brainstem Imaging Laboratory, Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States; Division of Sleep Medicine, Harvard University, Boston, MA.
| |
Collapse
|
5
|
Gonzalez JE, Musiek FE. The Onset-Offset N1-P2 Auditory Evoked Response in Individuals With High-Frequency Sensorineural Hearing Loss: Responses to Broadband Noise. Am J Audiol 2021; 30:423-432. [PMID: 34057857 DOI: 10.1044/2021_aja-20-00113] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Purpose Clinical use of electrophysiologic measures has been limited to use of brief stimuli to evoke responses. While brief stimuli elicit onset responses in individuals with normal hearing and normal central auditory nervous system (CANS) function, responses represent the integrity of a fraction of the mainly excitatory central auditory neurons. Longer stimuli could provide information regarding excitatory and inhibitory CANS function. Our goal was to measure the onset-offset N1-P2 auditory evoked response in subjects with normal hearing and subjects with moderate high-frequency sensorineural hearing loss (HFSNHL) to determine whether the response can be measured in individuals with moderate HFSNHL and, if so, whether waveform components differ between participant groups. Method Waveforms were obtained from 10 participants with normal hearing and seven participants with HFSNHL aged 40-67 years using 2,000-ms broadband noise stimuli with 40-ms rise-fall times presented at 50 dB SL referenced to stimulus threshold. Amplitudes and latencies were analyzed via repeated-measures analysis of variance (ANOVA). N1 and P2 onset latencies were compared to offset counterparts via repeated-measures ANOVA after subtracting 2,000 ms from the offset latencies to account for stimulus duration. Offset-to-onset trough-to-peak amplitude ratios between groups were compared using a one-way ANOVA. Results Responses were evoked from all participants. There were no differences between participant groups for the waveform components measured. Response × Participant Group interactions were not significant. Offset N1-P2 latencies were significantly shorter than onset counterparts after adjusting for stimulus duration (normal hearing: 43 ms shorter; HFSNHL: 47 ms shorter). Conclusions Onset-offset N1-P2 responses were resistant to moderate HFSNHL. It is likely that the onset was elicited by the presentation of a sound in silence and the offset by the change in stimulus envelope from plateau to fall, suggesting an excitatory onset response and an inhibitory-influenced offset response. Results indicated this protocol can be used to investigate CANS function in individuals with moderate HFSNHL. Supplemental Material https://doi.org/10.23641/asha.14669007.
Collapse
Affiliation(s)
- Jennifer E. Gonzalez
- Speech and Hearing Science, College of Health Solutions, Arizona State University, Tempe
| | - Frank E. Musiek
- Department of Speech, Language, and Hearing Sciences, The University of Arizona, Tucson
| |
Collapse
|
6
|
Suthakar K, Ryugo DK. Projections from the ventral nucleus of the lateral lemniscus to the cochlea in the mouse. J Comp Neurol 2021; 529:2995-3012. [PMID: 33754334 DOI: 10.1002/cne.25143] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 03/11/2021] [Accepted: 03/12/2021] [Indexed: 02/01/2023]
Abstract
Auditory efferents originate in the central auditory system and project to the cochlea. Although the specific anatomy of the olivocochlear (OC) efferents can vary between species, two types of auditory efferents have been identified based upon the general location of their cell bodies and their distinctly different axon terminations in the organ of Corti. In the mouse, the relatively small somata of the lateral (LOC) efferents reside in the lateral superior olive (LSO), have unmyelinated axons, and terminate around ipsilateral inner hair cells (IHCs), primarily against the afferent processes of type I auditory nerve fibers. In contrast, the larger somata of the medial (MOC) efferents are distributed in the ventral nucleus of the trapezoid body (VNTB), have myelinated axons, and terminate bilaterally against the base of multiple outer hair cells (OHCs). Using in vivo retrograde cell body marking, anterograde axon tracing, immunohistochemistry, and electron microscopy, we have identified a group of efferent neurons in mouse, whose cell bodies reside in the ventral nucleus of the lateral lemniscus (VNLL). By virtue of their location, we call them dorsal efferent (DE) neurons. Labeled DE cells were immuno-negative for tyrosine hydroxylase, glycine, and GABA, but immuno-positive for choline acetyltransferase. Morphologically, DEs resembled LOC efferents by their small somata, unmyelinated axons, and ipsilateral projection to IHCs. These three classes of efferent neurons all project axons directly to the cochlea and exhibit cholinergic staining characteristics. The challenge is to discover the contributions of this new population of neurons to auditory efferent function.
Collapse
Affiliation(s)
- Kirupa Suthakar
- Hearing Research, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia.,School of Medical Sciences, Faculty of Medicine, UNSW Australia, Sydney, New South Wales, Australia
| | - David K Ryugo
- Hearing Research, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia.,School of Medical Sciences, Faculty of Medicine, UNSW Australia, Sydney, New South Wales, Australia.,Department of Otolaryngology, Head, Neck & Skull Base Surgery, St. Vincent's Hospital, Sydney, New South Wales, Australia.,The Johns Hopkins University School of Medicine, Otolaryngology-HNS, Baltimore, Maryland, USA
| |
Collapse
|
7
|
Garrett A, Lannigan V, Yates NJ, Rodger J, Mulders W. Physiological and anatomical investigation of the auditory brainstem in the Fat-tailed dunnart ( Sminthopsis crassicaudata). PeerJ 2019; 7:e7773. [PMID: 31592349 PMCID: PMC6776069 DOI: 10.7717/peerj.7773] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 08/27/2019] [Indexed: 11/20/2022] Open
Abstract
The fat-tailed dunnart (Sminthopsis crassicaudata) is a small (10–20 g) native marsupial endemic to the south west of Western Australia. Currently little is known about the auditory capabilities of the dunnart, and of marsupials in general. Consequently, this study sought to investigate several electrophysiological and anatomical properties of the dunnart auditory system. Auditory brainstem responses (ABR) were recorded to brief (5 ms) tone pips at a range of frequencies (4–47.5 kHz) and intensities to determine auditory brainstem thresholds. The dunnart ABR displayed multiple distinct peaks at all test frequencies, similar to other mammalian species. ABR showed the dunnart is most sensitive to higher frequencies increasing up to 47.5 kHz. Morphological observations (Nissl stain) revealed that the auditory structures thought to contribute to the first peaks of the ABR were all distinguishable in the dunnart. Structures identified include the dorsal and ventral subdivisions of the cochlear nucleus, including a cochlear nerve root nucleus as well as several distinct nuclei in the superior olivary complex, such as the medial nucleus of the trapezoid body, lateral superior olive and medial superior olive. This study is the first to show functional and anatomical aspects of the lower part of the auditory system in the Fat-tailed dunnart.
Collapse
Affiliation(s)
- Andrew Garrett
- Department of Systems Neuroscience, J.F.B. Institute für Zoologie und Anthropologie, Universität Göttingen, Germany
- School of Biological Sciences, University of Western Australia, Crawley, Western Australia, Australia
| | - Virginia Lannigan
- School of Biological Sciences, University of Western Australia, Crawley, Western Australia, Australia
- School of Human Sciences, M311, University of Western Australia, Crawley, Western Australia, Australia
| | - Nathanael J. Yates
- School of Human Sciences, M311, University of Western Australia, Crawley, Western Australia, Australia
- The Queensland Brain Institute, University of Queensland, St Lucia, Queensland, Australia
| | - Jennifer Rodger
- School of Biological Sciences, University of Western Australia, Crawley, Western Australia, Australia
- School of Human Sciences, M311, University of Western Australia, Crawley, Western Australia, Australia
| | - Wilhelmina Mulders
- School of Human Sciences, M311, University of Western Australia, Crawley, Western Australia, Australia
- Ear Science Institute Australia, Subiaco, Western Australia, Australia
| |
Collapse
|
8
|
Plonek M, Nicpoń J, Kubiak K, Wrzosek M. A comparison of the brainstem auditory evoked response in healthy ears of unilaterally deaf dogs and bilaterally hearing dogs. Vet Res Commun 2017; 41:23-31. [PMID: 27896671 PMCID: PMC5306067 DOI: 10.1007/s11259-016-9668-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 11/09/2016] [Indexed: 10/31/2022]
Abstract
AIMS Auditory plasticity in response to unilateral deafness has been reported in various animal species. Subcortical changes occurring in unilaterally deaf young dogs using the brainstem auditory evoked response have not been evaluated yet. The aim of this study was to assess the brainstem auditory evoked response findings in dogs with unilateral hearing loss, and compare them with recordings obtained from healthy dogs. METHODS Brainstem auditory evoked responses (amplitudes and latencies of waves I, II, III, V, the V/I wave amplitude ratio, wave I-V, I-III and III-V interpeak intervals) were studied retrospectively in forty-six privately owned dogs, which were either unilaterally deaf or had bilateral hearing. The data obtained from the hearing ears in unilaterally deaf dogs were compared to values obtained from their healthy littermates. RESULTS Statistically significant differences in the amplitude of wave III and the V/I wave amplitude ratio at 75 dB nHL were found between the group of unilaterally deaf puppies and the control group. The recordings of dogs with single-sided deafness were compared, and the results showed no statistically significant differences in the latencies and amplitudes of the waves between left- (AL) and right-sided (AR) deafness. CONCLUSIONS The recordings of the brainstem auditory evoked response in canines with unilateral inborn deafness in this study varied compared to recordings from healthy dogs. Future studies looking into electrophysiological assessment of hearing in conjunction with imaging modalities to determine subcortical auditory plasticity and auditory lateralization in unilaterally deaf dogs are warranted.
Collapse
Affiliation(s)
- M. Plonek
- Department of Internal Diseases with Clinic for Horses, Dogs and Cats, The Faculty of Veterinary Medicine, Wroclaw University of Environmental and Life Sciences, pl. Grunwaldzki 47, 50-366 Wrocław, Poland
| | - J. Nicpoń
- Department of Internal Diseases with Clinic for Horses, Dogs and Cats, The Faculty of Veterinary Medicine, Wroclaw University of Environmental and Life Sciences, pl. Grunwaldzki 47, 50-366 Wrocław, Poland
- Centre for Experimental Diagnostics and Biomedical Innovations, Grunwaldzki sq. 47, 50-366 Wroclaw, Poland
| | - K. Kubiak
- Department of Internal Diseases with Clinic for Horses, Dogs and Cats, The Faculty of Veterinary Medicine, Wroclaw University of Environmental and Life Sciences, pl. Grunwaldzki 47, 50-366 Wrocław, Poland
| | - M. Wrzosek
- Department of Internal Diseases with Clinic for Horses, Dogs and Cats, The Faculty of Veterinary Medicine, Wroclaw University of Environmental and Life Sciences, pl. Grunwaldzki 47, 50-366 Wrocław, Poland
| |
Collapse
|
9
|
Otsuka S, Tsuzaki M, Sonoda J, Tanaka S, Furukawa S. A Role of Medial Olivocochlear Reflex as a Protection Mechanism from Noise-Induced Hearing Loss Revealed in Short-Practicing Violinists. PLoS One 2016; 11:e0146751. [PMID: 26745634 PMCID: PMC4706422 DOI: 10.1371/journal.pone.0146751] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2015] [Accepted: 12/20/2015] [Indexed: 11/26/2022] Open
Abstract
Previous studies have indicated that extended exposure to a high level of sound might increase the risk of hearing loss among professional symphony orchestra musicians. One of the major problems associated with musicians' hearing loss is difficulty in estimating its risk simply on the basis of the physical amount of exposure, i.e. the exposure level and duration. The aim of this study was to examine whether the measurement of the medial olivocochlear reflex (MOCR), which is assumed to protect the cochlear from acoustic damage, could enable us to assess the risk of hearing loss among musicians. To test this, we compared the MOCR strength and the hearing deterioration caused by one-hour instrument practice. The participants in the study were music university students who are majoring in the violin, whose left ear is exposed to intense violin sounds (broadband sounds containing a significant number of high-frequency components) during their regular instrument practice. Audiogram and click-evoked otoacoustic emissions (CEOAEs) were measured before and after a one-hour violin practice. There was a larger exposure to the left ear than to the right ear, and we observed a left-ear specific temporary threshold shift (TTS) after the violin practice. Left-ear CEOAEs decreased proportionally to the TTS. The exposure level, however, could not entirely explain the inter-individual variation in the TTS and the decrease in CEOAE. On the other hand, the MOCR strength could predict the size of the TTS and CEOAE decrease. Our findings imply that, among other factors, the MOCR is a promising measure for assessing the risk of hearing loss among musicians.
Collapse
Affiliation(s)
- Sho Otsuka
- NTT Communication Science Laboratories, NTT Corporation, 3-1 Morinosato Wakamiya, Atsugi, Kanagawa 243-0198, Japan
| | - Minoru Tsuzaki
- Kyoto City University of Arts, 13-6 Kutsukake-cho, Oe, Nishikyo-ku, Kyoto 610-1197, Japan
| | - Junko Sonoda
- Kyoto City University of Arts, 13-6 Kutsukake-cho, Oe, Nishikyo-ku, Kyoto 610-1197, Japan
| | - Satomi Tanaka
- Kyoto City University of Arts, 13-6 Kutsukake-cho, Oe, Nishikyo-ku, Kyoto 610-1197, Japan
| | - Shigeto Furukawa
- NTT Communication Science Laboratories, NTT Corporation, 3-1 Morinosato Wakamiya, Atsugi, Kanagawa 243-0198, Japan
| |
Collapse
|
10
|
Abstract
Auditory processing can be disrupted by brainstem lesions. It is estimated that approximately 57% of brainstem lesions are associated with auditory disorders. However diseases of the brainstem usually involve many structures, producing a plethora of other neurologic deficits, often relegating "auditory symptoms in the background." Lesions below or within the cochlear nuclei result in ipsilateral auditory-processing abnormalities detected in routine testing; disorders rostral to the cochlear nuclei may result in bilateral abnormalities or may be silent. Lesions in the superior olivary complex and trapezoid body show a mixture of ipsilateral, contralateral, and bilateral abnormalities, whereas lesions of the lateral lemniscus, inferior colliculus, and medial geniculate body do not affect peripheral auditory processing and result in predominantly subtle contralateral abnormalities that may be missed by routine auditory testing. In these cases psychophysical methods developed for the evaluation of central auditory function should be employed (e.g., dichotic listening, interaural time perception, sound localization). The extensive connections of the auditory brainstem nuclei not only are responsible for binaural interaction but also assure redundancy in the system. This redundancy may explain why small brainstem lesions are sometimes clinically silent. Any disorder of the brainstem (e.g., neoplasms, vascular disorders, infections, trauma, demyelinating disorders, neurodegenerative diseases, malformations) that involves the auditory pathways and/or centers may produce hearing abnormalities.
Collapse
|
11
|
Perrot X, Collet L. Function and plasticity of the medial olivocochlear system in musicians: a review. Hear Res 2013; 308:27-40. [PMID: 23994434 DOI: 10.1016/j.heares.2013.08.010] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2013] [Revised: 08/11/2013] [Accepted: 08/21/2013] [Indexed: 10/26/2022]
Abstract
The outer hair cells of the organ of Corti are the target of abundant efferent projections from the olivocochlear system. This peripheral efferent auditory subsystem is currently thought to be modulated by central activity via corticofugal descending auditory system, and to modulate active cochlear micromechanics. Although the function of this efferent subsystem remains unclear, physiological, psychophysical, and modeling data suggest that it may be involved in ear protection against noise damage and auditory perception, especially in the presence of background noise. Moreover, there is mounting evidence that its activity is modulated by auditory and visual attention. A commonly used approach to measure olivocochlear activity noninvasively in humans relies on the suppression of otoacoustic emissions by contralateral noise. Previous studies have found substantial interindividual variability in this effect, and statistical differences have been observed between professional musicians and non-musicians, with stronger bilateral suppression effects in the former. In this paper, we review these studies and discuss various possible interpretations for these findings, including experience-dependent neuroplasticity. We ask whether differences in olivocochlear function between musicians and non-musicians reflect differences in peripheral auditory function or in more central factors, such as top-down attentional modulation.
Collapse
Affiliation(s)
- Xavier Perrot
- Université de Lyon, Lyon F-69000, France; INSERM U1028, CNRS UMR5292, Université Lyon 1, Lyon Neuroscience Research Center, Brain Dynamics and Cognition Team, Lyon F-69000, France; Claude Bernard Lyon 1 University, Lyon F-69500, France; Hospices Civils de Lyon, Lyon Sud Teaching Hospital, Department of Audiology and Orofacial Explorations, Pierre-Bénite F-69310, France.
| | - Lionel Collet
- Université de Lyon, Lyon F-69000, France; INSERM U1028, CNRS UMR5292, Université Lyon 1, Lyon Neuroscience Research Center, Brain Dynamics and Cognition Team, Lyon F-69000, France; Claude Bernard Lyon 1 University, Lyon F-69500, France; Hospices Civils de Lyon, Lyon Sud Teaching Hospital, Department of Audiology and Orofacial Explorations, Pierre-Bénite F-69310, France.
| |
Collapse
|
12
|
Abstract
Interaural differences in stimulus intensity and timing are major cues for sound localization. In mammals, these cues are first processed in the lateral and medial superior olive by interaction of excitatory and inhibitory synaptic inputs from ipsi- and contralateral cochlear nucleus neurons. To preserve sound localization acuity following changes in the acoustic environment, the processing of these binaural cues needs neuronal adaptation. Recent studies have shown that binaural sensitivity adapts to stimulation history within milliseconds, but the actual extent of binaural adaptation is unknown. In the current study, we investigated long-term effects on binaural sensitivity using extracellular in vivo recordings from single neurons in the dorsal nucleus of the lateral lemniscus that inherit their binaural properties directly from the lateral and medial superior olives. In contrast to most previous studies, we used a noninvasive approach to influence this processing. Adult gerbils were exposed for 2 weeks to moderate noise with no stable binaural cue. We found monaural response properties to be unaffected by this measure. However, neuronal sensitivity to binaural cues was reversibly altered for a few days. Computational models of sensitivity to interaural time and level differences suggest that upregulation of inhibition in the superior olivary complex can explain the electrophysiological data.
Collapse
|
13
|
Alvarado JC, Fuentes-Santamaría V, Henkel CK. Rapid modifications in calretinin immunostaining in the deep layers of the superior colliculus after unilateral cochlear ablation. Hear Res 2008; 247:78-86. [PMID: 19017539 DOI: 10.1016/j.heares.2008.10.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2008] [Revised: 10/20/2008] [Accepted: 10/26/2008] [Indexed: 11/24/2022]
Abstract
Calretinin (CR) is a calcium-binding protein that plays an important role in the homeostasis of intracellular calcium concentration in the auditory pathway. To test if hearing loss could lead indirectly to modifications in levels of this calcium-binding protein in neurons and neuropilar structures outside of the lemniscal auditory pathway, CR-immunostaining was evaluated in the superior colliculus (SC) in adult ferrets at 1, 20 and 90 days after unilateral cochlear ablation. The results demonstrate that within 24h there was a significant increase in CR-immunostaining in ablated animals as indicated by an increase in the mean gray level of immunostaining in the deep, multisensory layers of the contralateral SC compared to the ipsilateral side and control ferrets. This upregulation was evident in both neurons and neuropil and did not change at the two subsequent time points. In contrast, there was no change in the superficial layers of the SC which have visual properties but no auditory inputs. These findings suggest that upregulation of CR levels within neurons and neuropil in the contralateral deep SC is subject to modifications by activity in multisynaptic auditory pathways. Therefore, cochlear-driven activity appears to affect calcium-binding protein levels not only in auditory nuclei but also in other neural structures whose response properties may be influenced by auditory-related activity.
Collapse
Affiliation(s)
- Juan Carlos Alvarado
- Regional Center for Biomedical Research (CRIB), Department of Medical Sciences, School of Medicine, University of Castilla-La Mancha, Albacete, Spain
| | | | | |
Collapse
|
14
|
Hutson KA, Durham D, Tucci DL. Consequences of unilateral hearing loss: time dependent regulation of protein synthesis in auditory brainstem nuclei. Hear Res 2007; 233:124-34. [PMID: 17919862 DOI: 10.1016/j.heares.2007.08.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2007] [Revised: 08/17/2007] [Accepted: 08/23/2007] [Indexed: 11/16/2022]
Abstract
Conductive hearing impairment results in marked changes in neuronal activity in the central auditory system, particularly in young animals [Tucci, D.L., Cant, N.B., Durham, D., 1999. Conductive hearing loss results in a decrease in central auditory system activity in the young gerbil. Laryngoscope 109, 1359-1371]. To better understand the effects of conductive hearing loss (CHL) on cellular metabolism, incorporation of (3)H-leucine was used as a measure of protein synthesis in immature postnatal day 21 gerbils subjected to either unilateral CHL by malleus removal or profound sensorineural hearing loss by cochlear ablation. (3)H-leucine uptake was measured after survival times of 6 or 48h. Protein synthesis values were standardized to measurements from the abducens nucleus and compared with measurements from sham animals at similar age/survival times. Protein synthesis in the medial superior olive (MSO) was found to be significantly down-regulated (bilaterally) after CHL in animals surviving 48h. However, 6h after CHL manipulation, protein synthesis is up-regulated in MSO (bilaterally) and in the ipsilateral medial nucleus of the trapezoid body.
Collapse
Affiliation(s)
- K A Hutson
- Department of Surgery, Division of Otolaryngology-Head and Neck Surgery, Duke University Medical Center, Box 3805, Durham, NC 27710, USA
| | | | | |
Collapse
|
15
|
Alvarado JC, Fuentes-Santamaria V, Franklin SR, Brunso-Bechtold JK, Henkel CK. Synaptophysin and insulin-like growth factor-1 immunostaining in the central nucleus of the inferior colliculus in adult ferrets following unilateral cochlear removal: a densitometric analysis. Synapse 2007; 61:288-302. [PMID: 17318882 DOI: 10.1002/syn.20373] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
In the present study, unilateral cochlear ablations were performed in adult ferrets to evaluate possible time-dependent modifications of synaptophysin and insulin-like growth factor-1 (IGF-1) in the central nucleus of the inferior colliculus (CNIC). Using densitometric analysis, synaptophysin and IGF-1 immunostaining were assessed at 1 (PA1) and 90 (PA90) days after cochlear ablation. The results demonstrated that 1 day after the lesion there was an increase in the levels of synaptophysin immunostaining bilaterally in the CNIC compared to control animals. That increase was no longer present at 90 days after the ablation. Overall levels of IGF-1 immunostaining at PA1 were increased significantly within neurons and neuropil. However, at PA90, only IGF-1 immunostaining contralateral to the lesion was elevated compared to control animals, although elevation was less than that observed at PA1. These results suggest that cochlear ablation appears to affect synaptophysin and IGF-1 protein levels bilaterally in the CNIC.
Collapse
Affiliation(s)
- Juan Carlos Alvarado
- Department of Neurobiology and Anatomy, Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA.
| | | | | | | | | |
Collapse
|
16
|
Alvarado JC, Fuentes-Santamaria V, Franklin SR, Brunso-Bechtold JK, Henkel CK. Unilateral cochlear ablation in adult ferrets results in upregulation in calretinin immunostaining in the central nucleus of the inferior colliculus. Neuroscience 2006; 136:957-69. [PMID: 16344163 DOI: 10.1016/j.neuroscience.2005.04.022] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2005] [Revised: 03/26/2005] [Accepted: 04/05/2005] [Indexed: 10/25/2022]
Abstract
In the present study, unilateral cochlear ablations were performed in adult ferrets in order to determine whether an upregulation of the calretinin immunostained plexus in the central nucleus of the inferior colliculus occurs and if so, what the time course of this upregulation is. Accordingly, the mean gray level and the calretinin-immunostained area of the axonal plexus in the central nucleus of the inferior colliculus were evaluated at 1, 20 and 90 days after cochlear ablation. In unoperated animals, the calretinin-immunostained plexus was bilaterally symmetric. In ablated animals, both the mean gray level and the immunostained area of the plexus increased in the central nucleus of the inferior colliculus contralateral to the lesion compared with both the ipsilateral side and unoperated animals. This upregulation was present 24 h after the ablation and did not change at the two subsequent time points. In a previous study in young ferrets, the immunostained area of the plexus in the central nucleus of the inferior colliculus contralateral to the lesion increased 200% compared with control ferrets [J Comp Neurol 460 (2003) 585], whereas it increased only 33% in adult ferrets. These findings suggest that 1) calretinin upregulation in the contralateral central nucleus of the inferior colliculus following cochlear ablation occurs by 24 h after cochlear ablation and 2) there is an age-related decline in the magnitude of this upregulation after cochlear ablation.
Collapse
Affiliation(s)
- J C Alvarado
- Department of Neurobiology and Anatomy, Wake Forest University School of Medicine, Winston-Salem, NC 27157-1010, USA. jalvarad@@wfubmc.edu
| | | | | | | | | |
Collapse
|
17
|
Jin YM, Godfrey DA. Effects of cochlear ablation on muscarinic acetylcholine receptor binding in the rat cochlear nucleus. J Neurosci Res 2006; 83:157-66. [PMID: 16307447 DOI: 10.1002/jnr.20706] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Cholinergic synapses in the cochlear nucleus (CN) have been reported to modulate spontaneous activity via muscarinic acetylcholine receptors. In this study, muscarinic receptor binding was measured as specific binding of 1-[N-methyl-(3)H]scopolamine in CN regions of control rats and 7 days, 1 month, and 2 months after unilateral cochlear ablation. In control rats, the strongest binding was found in granular regions, followed in order by fusiform soma, molecular, and deep layers of the dorsal cochlear nucleus (DCN), with much lower binding in the anteroventral CN (AVCN) and posteroventral CN (PVCN). After unilateral cochlear ablation, binding in the AVCN, PVCN, and their associated granular regions on the lesion side became progressively greater than on the control side through 2 months after lesion. A significant asymmetry, with binding higher on the lesion side, was also found in the DCN fusiform soma layer at 7 days, and there and in the DCN deep layer at 1 and 2 months after lesion. There was also evidence of increased binding on the control side in most CN regions. By contrast, binding in the ipsilateral facial nucleus decreased, compared with the control side, by 7 days after the lesion and showed some recovery toward symmetry by 2 months after lesion, and there was no evidence for contralateral changes. These muscarinic receptor binding changes reflect receptor plasticity after loss of auditory nerve innervation. Such plasticity may underlie some of the central auditory functional changes that occur following peripheral lesions, such as tinnitus and hyperacusis.
Collapse
Affiliation(s)
- Yong-Ming Jin
- Division of Otolaryngology, Department of Surgery, Medical University of Ohio, Toledo, 43614-5807, USA
| | | |
Collapse
|
18
|
Langers DRM, van Dijk P, Backes WH. Lateralization, connectivity and plasticity in the human central auditory system. Neuroimage 2005; 28:490-9. [PMID: 16051500 DOI: 10.1016/j.neuroimage.2005.06.024] [Citation(s) in RCA: 115] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2005] [Revised: 05/10/2005] [Accepted: 06/01/2005] [Indexed: 11/26/2022] Open
Abstract
Although it is known that responses in the auditory cortex are evoked predominantly contralateral to the side of stimulation, the lateralization of responses at lower levels in the human central auditory system has hardly been studied. Furthermore, little is known on the functional interactions between the involved processing centers. In this study, functional MRI was performed using sound stimuli of varying left and right intensities. In normal hearing subjects, contralateral activation was consistently detected in the temporal lobe, thalamus and midbrain. Connectivity analyses showed that auditory information crosses to the contralateral side in the lower brainstem followed by ipsilateral signal conduction towards the auditory cortex, similar to the flow of auditory signals in other mammals. In unilaterally deaf subjects, activation was more symmetrical for the cortices but remained contralateral in the midbrain and thalamus. Input connection strengths were different only at cortical levels, and there was no evidence for plastic reorganization at subcortical levels.
Collapse
Affiliation(s)
- Dave R M Langers
- Department of Radiology, Maastricht University Hospital, P.O. Box 5800, 6202 AZ Maastricht, The Netherlands
| | | | | |
Collapse
|
19
|
Templin T, Simmons AM. Cellular and spatial changes in the anuran superior olive across metamorphosis. Hear Res 2005; 207:87-98. [PMID: 15950413 DOI: 10.1016/j.heares.2005.04.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2005] [Revised: 04/05/2005] [Accepted: 04/06/2005] [Indexed: 11/22/2022]
Abstract
In many vertebrate species, the superior olive in the auditory brainstem plays an essential role in sound source localization. Little is known, however, about the structural and functional changes in this nucleus during development when alterations in head size and shape as well as in inner ear projections are expected to affect the perception of binaural cues. Using stereological techniques, we investigated the changes in several cellular and spatial features of the bullfrog superior olive across metamorphosis, the time period during which the animal transforms from a totally aquatic larva to a semiterrestrial adult. The total number of cells shows a strongly linear increase from hatchling through late larval stages. The number of neurons decreases during metamorphic climax stages, and recovers to pre-metamorphic climax levels in the early post-metamorphic froglet stage. The number of glial cells increases during the early larval period, and remains relatively stable, with no systematic variation, from late larval to froglet stages. The volume of the superior olive increases rapidly in early larval stages, followed by a much-attenuated rate of growth between late larval and froglet stages. These morphological changes may provide a substrate for the functional restructuring of the bullfrog superior olive, shortly before the switch from aquatic to mostly atmospheric hearing.
Collapse
Affiliation(s)
- Thomas Templin
- Department of Psychology, Brown University, Providence, RI 02912, USA
| | | |
Collapse
|
20
|
Illing RB, Kraus KS, Meidinger MA. Reconnecting neuronal networks in the auditory brainstem following unilateral deafening. Hear Res 2005; 206:185-99. [PMID: 16081008 DOI: 10.1016/j.heares.2005.01.016] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2004] [Accepted: 01/10/2005] [Indexed: 11/27/2022]
Abstract
When we disturbed the auditory input of the adult rat by cochleotomy or noise trauma on one side, several substantial anatomical, cellular, and molecular changes took place in the auditory brainstem. We found that: (1) cochleotomy or severe noise trauma both lead to a considerable increase of immunoreactivity of the growth-associated protein GAP-43 in the ventral cochlear nucleus (VCN) of the affected side; (2) the expression of GAP-43 in VCN is restricted to presynaptic endings and short fiber segments; (3) axon collaterals of the cholinergic medial olivocochlear (MOC) neurons are the path along which GAP-43 reaches VCN; (4) partial cochlear lesions induce the emergence of GAP-43 positive presynaptic endings only in regions tonotopically corresponding to the extent of the lesion; (5) judging from the presence of immature fibers and growth cones in VCN on the deafened side, at least part of the GAP-43 positive presynaptic endings appear to be newly formed neuronal contacts following axonal sprouting while others may be modified pre-existing contacts; and (6) GAP-43 positive synapses are formed only on specific postsynaptic profiles, i.e., glutamatergic, glycinergic and calretinin containing cell bodies, but not GABAergic cell bodies. We conclude that unilateral deafening, be it partial or total, induces complex patterns of reconnecting neurons in the adult auditory brainstem, and we evaluate the possibility that the deafness-induced chain of events is optimized to remedy the loss of a bilaterally balanced activity in the auditory brainstem.
Collapse
Affiliation(s)
- Robert-Benjamin Illing
- Neurobiological Research Laboratory, Department of Otorhinolaryngology, University of Freiburg, D-79106 Freiburg, Germany.
| | | | | |
Collapse
|
21
|
Fuentes-Santamaria V, Alvarado JC, Taylor AR, Brunso-Bechtold JK, Henkel CK. Quantitative changes in calretinin immunostaining in the cochlear nuclei after unilateral cochlear removal in young ferrets. J Comp Neurol 2005; 483:458-75. [PMID: 15700274 PMCID: PMC1913210 DOI: 10.1002/cne.20437] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Neurons of the cochlear nuclei receive axosomatic endings from primary afferent fibers from the cochlea and have projections that diverge to form parallel ascending auditory pathways. These cells are characterized by neurochemical phenotypes such as levels of calretinin. To test whether or not early deafferentation results in changes in calretinin immunostaining in the cochlear nucleus, unilateral cochlear ablations were performed in ferrets soon after hearing onset (postnatal day [P]30-P40). Two months later, changes in calretinin immunostaining as well as cell size, volume, and synaptophysin immunostaining were assessed in the anteroventral (AVCN), posteroventral (PVCN), and dorsal cochlear nucleus (DCN). A decrease in calretinin immunostaining was evident ipsilaterally within the AVCN and PVCN but not in the DCN. Further analysis revealed a decrease both in the calretinin-immunostained neuropil and in the calretinin-immunostained area within AVCN and PVCN neurons. These declines were accompanied by significant ipsilateral decreases in volume as well as neuron area in the AVCN and PVCN compared with the contralateral cochlear nucleus and unoperated animals, but not compared with the DCN. In addition, there was a significant contralateral increase in calretinin-immunostained area within AVCN and PVCN neurons compared with control animals. Finally, a decrease in area of synaptophysin immunostaining in both the ipsilateral AVCN and PVCN without changes in the number of boutons was found. The present data demonstrate that unilateral cochlear ablation leads to 1) decreased immunostaining of the neuropil in the AVCN and PVCN ipsilaterally, 2) decreased calretinin immunostaining within AVCN and PVCN neurons ipsilaterally, 3) synaptogenesis in the AVCN and PVCN ipsilaterally, and 4) increased calretinin immunostaining within AVCN and PVCN neurons contralaterally.
Collapse
Affiliation(s)
- Verónica Fuentes-Santamaria
- Department of Neurobiology and Anatomy, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157-1010, USA.
| | | | | | | | | |
Collapse
|
22
|
Schmerber S, Sheykholeslami K, Kermany MH, Hotta S, Kaga K. Time–intensity trading in bilateral congenital aural atresia patients. Hear Res 2005; 202:248-57. [PMID: 15811716 DOI: 10.1016/j.heares.2004.11.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2004] [Accepted: 11/19/2004] [Indexed: 10/26/2022]
Abstract
In an effort to examine the rules by which information of bilaterally applied bone-conducted signals arising from interaural time differences (ITD) and interaural intensity differences (IID) is combined, data were measured for continuous 500 Hz narrow band noise at 65-70 dB HL in 11 patients with bilateral congenital aural atresia. Time-intensity trading functions were obtained by shifting the sound image towards one side using ITD, and shifting back to a centered sound image by varying the IID in the same ear (auditory midline task). ITD values were varied from -600 to +600 micros at 200 micros steps, where negative values indicate delays to the right ear. The results indicate that time-intensity trading is present in patients with bilateral aural atresia. The gross response properties of time-intensity trading in response to bone-conducted signals were comparable in patients with bilateral aural atresia and normal-hearing subjects, though there was a larger inter-subject variability and higher discrimination thresholds across IIDs in the atresia group. These results suggest that the mature auditory brainstem has a potential to employ binaural cues later in life, although to a restricted degree. A binaural fitting of a bone-conducted hearing aid might optimize binaural hearing and improve sound lateralization, and we recommend now systematically bilateral fitting in aural atresia patients.
Collapse
Affiliation(s)
- Sébastien Schmerber
- Department of Otolaryngology, University Hospital, Service O.R.L C.H.U de Grenoble, France.
| | | | | | | | | |
Collapse
|
23
|
Alvarado JC, Fuentes-Santamaria V, Henkel CK, Brunso-Bechtold JK. Alterations in calretinin immunostaining in the ferret superior olivary complex after cochlear ablation. J Comp Neurol 2004; 470:63-79. [PMID: 14755526 DOI: 10.1002/cne.11038] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
In this study, we used image analysis to assess changes in calretinin immunoreactivity in the lateral (LSO) and medial (MSO) superior olivary nuclei in ferrets 2 months after unilateral cochlear ablations at 30-40 days of age, soon after hearing onset. These two nuclei are the first significant sites of binaural convergence in the ascending auditory system, and both receive direct projections from the deafferented cochlear nucleus. Cochlear ablation results in a decrease in the overall level of calretinin immunostaining within the LSO ipsilaterally compared with the contralateral side and with control animals and within the MSO bilaterally compared with control ferrets. In addition, the level of calretinin immunostaining ipsilaterally within neurons in the LSO was significantly less in cochlear ablated than control animals. In contrast, there was no effect of cochlear ablation on the level of calretinin immunostaining within neurons either in the contralateral LSO or in the MSO. These results are consistent with a downregulation in calretinin within the neuropil of MSO bilaterally and LSO ipsilaterally, as well as a downregulation in calretinin within somata in the ipsilateral LSO as a result of unilateral cochlear ablation soon after hearing onset. Thus, cochlear-driven activity appears to affect calcium binding protein levels in both neuropil and neurons within the superior olivary complex.
Collapse
Affiliation(s)
- Juan Carlos Alvarado
- Department of Neurobiology and Anatomy, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157-1010, USA.
| | | | | | | |
Collapse
|
24
|
|
25
|
Michler SA, Illing RB. Molecular plasticity in the rat auditory brainstem: modulation of expression and distribution of phosphoserine, phospho-CREB and TrkB after noise trauma. Audiol Neurootol 2003; 8:190-206. [PMID: 12811001 DOI: 10.1159/000071060] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2002] [Accepted: 02/21/2003] [Indexed: 11/19/2022] Open
Abstract
We induced acoustic trauma by applying click stimuli of 130 dB (SPL) for 30 min to one ear of adult rats. This treatment resulted in an instant and permanent threshold shift of 96 dB in the affected ear. A massive reduction of cochlear nerve fibers in the ventral cochlear nucleus (VCN) was demonstrated by tracing them from the cochlea of rats that survived acoustic overstimulation for 1 year or longer. In the auditory brainstem, we observed a deprivation-dependent appearance of fibers positive for tyrosine receptor kinase B in the ipsilateral VCN between day 3 and day 21 after trauma and an increase in phosphoserine immunostaining in the neuropil of the ipsilateral VCN and in neurons of the contralateral lateral superior olive during the first 30 days after trauma. Immunoreactivity for the cAMP response element binding protein in its phosphorylated form was transiently depressed in the ipsilateral inferior colliculus immediately after trauma and was elevated as late as 7 months after trauma in the ipsilateral VCN. Apparently, a unilateral acoustic overstimulation entails specific regulations of the activity of plasticity-associated molecules through phosphorylation and includes changes to neurotrophin signaling between neurons of the auditory brainstem.
Collapse
Affiliation(s)
- Steffen A Michler
- Neurobiological Research Laboratory, Department of Otorhinolaryngology, University of Freiburg, Freiburg, Germany
| | | |
Collapse
|
26
|
Michler SA, Illing RB. Acoustic trauma induces reemergence of the growth- and plasticity-associated protein GAP-43 in the rat auditory brainstem. J Comp Neurol 2002; 451:250-66. [PMID: 12210137 DOI: 10.1002/cne.10348] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
We explored the consequences of unilateral acoustic trauma to intracochlear and central nervous system structures in rats. An acoustic trauma, induced by applying click stimuli of 130 dB (sound pressure level; SPL) for 30 minutes, resulted in an instant and permanent threshold shift of 95.92 +/- 1.08 dB (SEM) in the affected ear. We observed, as a consequence, a structural deterioration of the organ of Corti. Deprivation-dependent changes of neurons of the auditory brainstem were determined using antibodies against neurofilament and the growth-associated protein GAP-43 and compared with those following cochleotomy, studied earlier. By 231 days posttrauma, spiral ganglion cell bodies and their processes were almost entirely lost from all cochlear regions with destroyed organ of Corti. In the lateral superior olive (LSO) ipsilateral to the trauma, cell bodies of lateral olivocochlear neurons turned transiently GAP-43 positive within the first 1.5 years posttrauma. The time course of emergence and disappearance of this population of neurons was similar to that found after cochleotomy. Additionally, after noise trauma, principal cells in contralateral LSO and in medial superior olive (MSO) on both sides of the brainstem developed an expression of GAP-43 that began 3 and 16 days posttrauma, respectively, and lasted for at least 1 year. Such cells were rarely observed after cochleotomy. An unequivocal rise in GAP-43 immunoreactivity was also found in the neuropil of the inferior colliculus and the ventral cochlear nucleus, both preferentially on the acoustically damaged side. We conclude that the degree and specific cause of sudden unilateral deafness entail specific patterns of plasticity responses in the auditory brainstem, possibly to prevent the neural network dedicated to locate sounds in the environment from delivering erroneous signals centralward.
Collapse
Affiliation(s)
- Steffen A Michler
- Neurobiological Research Laboratory, Department of Otorhinolaryngology, University of Freiburg, D-79106 Freiburg, Germany
| | | |
Collapse
|
27
|
Illing RB, Michler SA, Kraus KS, Laszig R. Transcription factor modulation and expression in the rat auditory brainstem following electrical intracochlear stimulation. Exp Neurol 2002; 175:226-44. [PMID: 12009775 DOI: 10.1006/exnr.2002.7895] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Neuronal activity in sensory organs elicited by adequate or electrical stimulation not only invokes fast electrical responses but may also trigger complex molecular changes inside central neurons. Following electrical intracochlear stimulation with a cochlear implant under urethane anesthesia, we observed changes in the phosphorylation state of the cAMP response element binding protein (CREB) and the expression of the immediate-early genes c-fos and egr-1, molecules known to act as transcription factors, in a tonotopically precise pattern in central auditory neurons. These neurons resided in the posteroventral and anteroventral cochlear nucleus, the dorsal cochlear nucleus, the lateral superior olive, the medial nucleus of the trapezoid body, the dorsal and ventral nucleus of the lateral lemniscus, and the central nucleus of the inferior colliculus. Moreover, effects of electrical stimulation were identified in the medial vestibular nucleus and the lateral parabrachial nucleus. Regionally, CREB was dephosphorylated wherever immediate-early gene expression went up. These massive stimulation-dependent modulations of transcription factors in the ascending auditory system are indicative of ongoing changes that modify the chemistry and structure of the affected cells and, consequently, their response characteristics to subsequent stimulation of the inner ear.
Collapse
Affiliation(s)
- Robert-Benjamin Illing
- Neurobiological Research Laboratory, Department of Otorhinolaryngology, University of Freiburg, Killianstrasse 5, Freiburg, D-79106, Germany.
| | | | | | | |
Collapse
|
28
|
Identification of the differentiation-associated Na+/PI transporter as a novel vesicular glutamate transporter expressed in a distinct set of glutamatergic synapses. J Neurosci 2002. [PMID: 11756497 DOI: 10.1523/jneurosci.22-01-00142.2002] [Citation(s) in RCA: 329] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Glutamate transport into synaptic vesicles is a prerequisite for its regulated neurosecretion. Here we functionally identify a second isoform of the vesicular glutamate transporter (VGLUT2) that was previously identified as a plasma membrane Na+-dependent inorganic phosphate transporter (differentiation-associated Na+/P(I) transporter). Studies using intracellular vesicles from transiently transfected PC12 cells indicate that uptake by VGLUT2 is highly selective for glutamate, is H+ dependent, and requires Cl- ion. Both the vesicular membrane potential (Deltapsi) and the proton gradient (DeltapH) are important driving forces for vesicular glutamate accumulation under physiological Cl- concentrations. Using an antibody specific for VGLUT2, we also find that this protein is enriched on synaptic vesicles and selective for a distinct class of glutamatergic nerve terminals. The pathway-specific, complementary expression of two different vesicular glutamate transporters suggests functional diversity in the regulation of vesicular release at excitatory synapses. Together, the two isoforms may account for the uptake of glutamate by synaptic vesicles from all central glutamatergic neurons.
Collapse
|
29
|
Illing RB, Michler SA. Modulation of P-CREB and expression of c-fos in cochlear nucleus and superior olive following electrical intracochlear stimulation. Neuroreport 2001; 12:875-8. [PMID: 11277600 DOI: 10.1097/00001756-200103260-00050] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Investigating activity-dependent plasticity in the auditory brain stem of the adult rat, we observed that electrical intracochlear stimulation led to a tonotopically localized modulation of the phosphorylation of the cAMP response element binding protein (CREB) and an equally localized expression of the immediate early gene product c-Fos in cochlear nucleus and superior olive. As P-CREB is thought to act as transcription factor on one promoter site of the c-fos gene, we compared immunolabeling for P-CREB and c-fos in adjacent brain sections. Following 2h sustained stimulation in previously deafened animals, labelling for P-CREB declined in regions where c-Fos labelling increased. This suggests that the level or state of P-CREB (e.g. whether it is phosphorylated or not) are affected by intracochlear stimulation in a process that appears to be linked to the stimulation-dependent expression of c-Fos in auditory brain stem nuclei.
Collapse
Affiliation(s)
- R B Illing
- Department of Otorhinolaryngology, University of Freiburg, Germany
| | | |
Collapse
|