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Schlee W, Hall DA, Edvall NK, Langguth B, Canlon B, Cederroth CR. Visualization of Global Disease Burden for the Optimization of Patient Management and Treatment. Front Med (Lausanne) 2017; 4:86. [PMID: 28674694 PMCID: PMC5475418 DOI: 10.3389/fmed.2017.00086] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Accepted: 06/06/2017] [Indexed: 12/27/2022] Open
Abstract
Background The assessment and treatment of complex disorders is challenged by the multiple domains and instruments used to evaluate clinical outcome. With the large number of assessment tools typically used in complex disorders comes the challenge of obtaining an integrative view of disease status to further evaluate treatment outcome both at the individual level and at the group level. Radar plots appear as an attractive visual tool to display multivariate data on a two-dimensional graphical illustration. Here, we describe the use of radar plots for the visualization of disease characteristics applied in the context of tinnitus, a complex and heterogeneous condition, the treatment of which has shown mixed success. Methods Data from two different cohorts, the Swedish Tinnitus Outreach Project (STOP) and the Tinnitus Research Initiative (TRI) database, were used. STOP is a population-based cohort where cross-sectional data from 1,223 non-tinnitus and 933 tinnitus subjects were analyzed. By contrast, the TRI contained data from 571 patients who underwent various treatments and whose Clinical Global Impression (CGI) score was accessible to infer treatment outcome. In the latter, 34,560 permutations were tested to evaluate whether a particular ordering of the instruments could reflect better the treatment outcome measured with the CGI. Results Radar plots confirmed that tinnitus subtypes such as occasional and chronic tinnitus from the STOP cohort could be strikingly different, and helped appreciate a gender bias in tinnitus severity. Radar plots with greater surface areas were consistent with greater burden, and enabled a rapid appreciation of the global distress associated with tinnitus in patients categorized according to tinnitus severity. Permutations in the arrangement of instruments allowed to identify a configuration with minimal variance and maximized surface difference between CGI groups from the TRI database, thus affording a means of optimally evaluating the outcomes in individual patients. Conclusion We anticipate such a tool to become a starting point for more sophisticated measures in clinical outcomes, applicable not only in the context of tinnitus but also in other complex diseases where the integration of multiple variables is needed for a comprehensive evaluation of treatment response.
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Basinou V, Park JS, Cederroth CR, Canlon B. Circadian regulation of auditory function. Hear Res 2017; 347:47-55. [PMID: 27665709 PMCID: PMC5364078 DOI: 10.1016/j.heares.2016.08.018] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Accepted: 08/25/2016] [Indexed: 12/11/2022]
Abstract
The circadian system integrates environmental cues to regulate physiological functions in a temporal fashion. The suprachiasmatic nucleus, located in the hypothalamus, is the master clock that synchronizes central and peripheral organ clocks to orchestrate physiological functions. Recently, molecular clock machinery has been identified in the cochlea unravelling the potential involvement in the circadian regulation of auditory functions. Here, we present background information on the circadian system and review the recent findings that introduce circadian rhythms to the auditory field. Understanding the mechanisms by which circadian rhythms regulate auditory function will provide fundamental knowledge on the signalling networks that control vulnerability and resilience to auditory insults.
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Moreno-Paublete R, Canlon B, Cederroth CR. Differential Neural Responses Underlying the Inhibition of the Startle Response by Pre-Pulses or Gaps in Mice. Front Cell Neurosci 2017; 11:19. [PMID: 28239338 PMCID: PMC5302757 DOI: 10.3389/fncel.2017.00019] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Accepted: 01/23/2017] [Indexed: 11/17/2022] Open
Abstract
Gap pre-pulse inhibition of the acoustic startle (GPIAS) is a behavioral paradigm used for inferring the presence of tinnitus in animal models as well as humans. In contrast to pre-pulse inhibition (PPI), the neural circuitry controlling GPIAS is poorly understood. To increase our knowledge on GPIAS, a comparative study with PPI was performed in mice combining these behavioral tests and c-Fos activity mapping in brain areas involved in the inhibition of the acoustic startle reflex (ASR). Both pre-pulses and gaps efficiently inhibited the ASR and abolished the induction of c-Fos in the pontine reticular nucleus. Differential c-Fos activation was found between PPI and GPIAS in the forebrain whereby PPI activated the lateral globus pallidus and GPIAS activated the primary auditory cortex. Thus, different neural maps are regulating the inhibition of the startle response by pre-pulses or gaps. To further investigate this differential response to PPI and GPIAS, we pharmacologically disrupted PPI and GPIAS with D-amphetamine or Dizocilpine (MK-801) to target dopamine efflux and to block NMDA receptors, respectively. Both D-amp and MK-801 efficiently decreased PPI and GPIAS. We administered Baclofen, an agonist GABAB receptor, but failed to detect any robust rescue of the effects of D-amp and MK-801 suggesting that PPI and GPIAS are GABAB-independent. These novel findings demonstrate that the inhibition of the ASR by pre-pulses or gaps is orchestrated by different neural pathways.
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Müller K, Edvall NK, Idrizbegovic E, Huhn R, Cima R, Persson V, Leineweber C, Westerlund H, Langguth B, Schlee W, Canlon B, Cederroth CR. Validation of Online Versions of Tinnitus Questionnaires Translated into Swedish. Front Aging Neurosci 2016; 8:272. [PMID: 27920720 PMCID: PMC5118447 DOI: 10.3389/fnagi.2016.00272] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Accepted: 10/28/2016] [Indexed: 01/11/2023] Open
Abstract
Background: Due to the lack of objective measures for assessing tinnitus, its clinical evaluation largely relies on the use of questionnaires and psychoacoustic tests. A global assessment of tinnitus burden would largely benefit from holistic approaches that not only incorporate measures of tinnitus but also take into account associated fears, emotional aspects (stress, anxiety, and depression), and quality of life. In Sweden, only a few instruments are available for assessing tinnitus, and the existing tools lack validation. Therefore, we translated a set of questionnaires into Swedish and evaluated their reliability and validity in a group of tinnitus subjects. Methods: We translated the English versions of the Tinnitus Functional Index (TFI), the Fear of Tinnitus Questionnaire (FTQ), the Tinnitus Catastrophizing Scale (TCS), the Perceived Stress Questionnaire (PSQ-30), and the Tinnitus Sample Case History Questionnaire (TSCHQ) into Swedish. These translations were delivered via the internet with the already existing Swedish versions of the Tinnitus Handicap Inventory (THI), the Hospital Anxiety and Depression Scale (HADS), the Hyperacusis Questionnaire (HQ), and the World Health Organization Quality of Life questionnaire (WHOQoL-BREF). Psychometric properties were evaluated by means of internal consistency [Cronbach's alpha (α)] and test–retest reliability across a 9-week interval [Intraclass Correlation Coefficient (ICC), Cohen's kappa] in order to establish construct as well as clinical validity using a sample of 260 subjects from a population-based cohort. Results: Internal consistency was acceptable for all questionnaires (α > 0.7) with the exception of the “social relationships” subscale of the WHOQoL-BREF. Test–retest reliability was generally acceptable (ICC > 0.70, Cohens kappa > 0.60) for the tinnitus-related questionnaires, except for the TFI “sense of control” subscale and 15 items of the TSCHQ. Spearmen rank correlations showed that almost all questionnaires on tinnitus are significantly related, indicating that these questionnaires measure different aspects of the same construct. The data supported good clinical validity of the tinnitus-related questionnaires. Conclusion: Our results suggest that most Swedish adaptations of the questionnaires are suitable for clinical and research settings and should facilitate the assessment of treatment outcomes using a more holistic approach by including measures of tinnitus fears, emotional burden, and quality of life.
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Yu H, Vikhe Patil K, Han C, Fabella B, Canlon B, Someya S, Cederroth CR. GLAST Deficiency in Mice Exacerbates Gap Detection Deficits in a Model of Salicylate-Induced Tinnitus. Front Behav Neurosci 2016; 10:158. [PMID: 27582696 PMCID: PMC4987341 DOI: 10.3389/fnbeh.2016.00158] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Accepted: 08/03/2016] [Indexed: 12/04/2022] Open
Abstract
Gap detection or gap pre-pulse inhibition of the acoustic startle (GPIAS) has been successfully used in rat and guinea pig models of tinnitus, yet this system has been proven to have low efficacy in CBA mice, with low basal GPIAS and subtle tinnitus-like effects. Here, we tested five mouse strains (CBA, BalbC, CD-1, C57BL/6 and 129sv) for pre-pulse inhibition (PPI) and gap detection with varying interstimulus intervals (ISI) and found that mice from a CBA genetic background had the poorest capacities of suppressing the startle response in the presence of a pre-pulse or a gap. CD-1 mice displayed variable responses throughout all ISI. Interestingly, C57BL/6, 129sv and BalbC showed efficient suppression with either pre-pulses or gaps with shorter ISI. The glutamate aspartate transporter (GLAST) is expressed in support cells from the cochlea and buffers the excess of glutamate. We hypothesized that loss of GLAST function could sensitize the ear to tinnitus-inducing agents, such as salicylate. Using shorter ISI to obtain a greater dynamic range to assess tinnitus-like effects, we found that disruption of gap detection by salicylate was exacerbated across various intensities of a 32-kHz narrow band noise gap carrier in GLAST knockout (KO) mice when compared to their wild-type (WT) littermates. Auditory brainstem responses (ABR) and distortion-product otoacoustic emission (DPOAE) were performed to evaluate the effects on hearing functions. Salicylate caused greater auditory threshold shifts (near 15 dB) in GLAST KO mice than in WT mice across all tested frequencies, despite similarly reduced DPOAE. Despite these changes, inhibition using broad-band gap carriers and 32 kHz pre-pulses were not affected. Our study suggests that GLAST deficiency could become a useful experimental model to decipher the mechanisms underlying drug-induced tinnitus. Future studies addressing the neurological correlates of tinnitus in this model could provide additional insights into the mechanisms of tinnitus.
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Park JS, Cederroth CR, Basinou V, Meltser I, Lundkvist G, Canlon B. Identification of a Circadian Clock in the Inferior Colliculus and Its Dysregulation by Noise Exposure. J Neurosci 2016; 36:5509-19. [PMID: 27194331 PMCID: PMC4871986 DOI: 10.1523/jneurosci.3616-15.2016] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Revised: 03/24/2016] [Accepted: 04/13/2016] [Indexed: 11/21/2022] Open
Abstract
UNLABELLED Circadian rhythms regulate bodily functions within 24 h and long-term disruptions in these rhythms can cause various diseases. Recently, the peripheral auditory organ, the cochlea, has been shown to contain a self-sustained circadian clock that regulates differential sensitivity to noise exposure throughout the day. Animals exposed to noise during the night are more vulnerable than when exposed during the day. However, whether other structures throughout the auditory pathway also possess a circadian clock remains unknown. Here, we focus on the inferior colliculus (IC), which plays an important role in noise-induced pathologies such as tinnitus, hyperacusis, and audiogenic seizures. Using PER2::LUC transgenic mice and real-time bioluminescence recordings, we revealed circadian oscillations of Period 2 protein in IC explants for up to 1 week. Clock genes (Cry1, Bmal1, Per1, Per2, Rev-erbα, and Dbp) displayed circadian molecular oscillations in the IC. Averaged expression levels of early-induced genes and clock genes during 24 h revealed differential responses to day or night noise exposure. Rev-erbα and Dbp genes were affected only by day noise exposure, whereas Per1 and Per2 were affected only by night noise exposure. However, the expression of Bdnf was affected by both day and night noise exposure, suggesting that plastic changes are unlikely to be involved in the differences in day or night noise sensitivity in the IC. These novel findings highlight the importance of circadian responses in the IC and emphasize the importance of circadian mechanisms for understanding central auditory function and disorders. SIGNIFICANCE STATEMENT Recent findings identified the presence of a circadian clock in the inner ear. Here, we present novel findings that neurons in the inferior colliculus (IC), a central auditory relay structure involved in sound processing, express a circadian clock as evidenced at both the mRNA and protein levels. Using a reporter mouse that expresses a luciferase protein coupled to the core clock protein PERIOD2 (PER2::LUC), we could observe spontaneous circadian oscillations in culture. Furthermore, we reveal that the mRNA profile of clock-related genes in the IC is altered differentially by day or night noise exposure. The identification of a clock in the IC is relevant for understanding the mechanisms underlying dysfunctions of the IC such as tinnitus, hyperacusis, or audiogenic seizures.
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Cederroth CR, Canlon B, Langguth B. Hearing loss and tinnitus--are funders and industry listening? Nat Biotechnol 2014; 31:972-4. [PMID: 24213768 DOI: 10.1038/nbt.2736] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Canlon B. Progress in hearing research 2014. Hear Res 2014; 311:1-2. [PMID: 25151010 DOI: 10.1016/j.heares.2014.02.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Accepted: 02/18/2014] [Indexed: 11/19/2022]
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Dallos P, Canlon B. Introduction to “good vibrations”: a special issue to celebrate the 50th anniversary of the Nobel Prize to Georg von Békésy. Hear Res 2013; 293:1-2. [PMID: 23210130 DOI: 10.1016/j.heares.2012.08.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Hébert S, Canlon B, Hasson D. Emotional exhaustion as a predictor of tinnitus. PSYCHOTHERAPY AND PSYCHOSOMATICS 2013; 81:324-6. [PMID: 22854311 DOI: 10.1159/000335043] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2011] [Accepted: 11/13/2011] [Indexed: 11/19/2022]
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Hasson D, Theorell T, Bergquist J, Canlon B. Acute stress induces hyperacusis in women with high levels of emotional exhaustion. PLoS One 2013; 8:e52945. [PMID: 23301005 PMCID: PMC3534646 DOI: 10.1371/journal.pone.0052945] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2012] [Accepted: 11/22/2012] [Indexed: 11/18/2022] Open
Abstract
Background Hearing problems is one of the top ten public health disorders in the general population and there is a well-established relationship between stress and hearing problems. The aim of the present study was to explore if an acute stress will increase auditory sensitivity (hyperacusis) in individuals with high levels of emotional exhaustion (EE). Methods Hyperacusis was assessed using uncomfortable loudness levels (ULL) in 348 individuals (140 men; 208 women; age 23–71 years). Multivariate analyses (ordered logistic regression), were used to calculate odds ratios, including interacting or confounding effects of age, gender, ear wax and hearing loss (PTA). Two-way ANCOVAs were used to assess possible differences in mean ULLs between EE groups pre- and post-acute stress task (a combination of cold pressor, emotional Stroop and Social stress/video recording). Results There were no baseline differences in mean ULLs between the three EE groups (one-way ANOVA). However, after the acute stress exposure there were significant differences in ULL means between the EE-groups in women. Post-hoc analyses showed that the differences in mean ULLs were between those with high vs. low EE (range 5.5–6.5 dB). Similar results were found for frequencies 0.5 and 1 kHz. The results demonstrate that women with high EE-levels display hyperacusis after an acute stress task. The odds of having hyperacusis were 2.5 (2 kHz, right ear; left ns) and 2.2 (4 kHz, right ear; left ns) times higher among those with high EE compared to those with low levels. All these results are adjusted for age, hearing loss and ear wax. Conclusion Women with high levels of emotional exhaustion become more sensitive to sound after an acute stress task. This novel finding highlights the importance of including emotional exhaustion in the diagnosis and treatment of hearing problems.
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Canlon B, Theorell T, Hasson D. Associations between stress and hearing problems in humans. Hear Res 2013; 295:9-15. [DOI: 10.1016/j.heares.2012.08.015] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2012] [Revised: 08/24/2012] [Accepted: 08/27/2012] [Indexed: 12/20/2022]
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Trune DR, Canlon B. Corticosteroid therapy for hearing and balance disorders. Anat Rec (Hoboken) 2012; 295:1928-43. [PMID: 23044978 PMCID: PMC3999710 DOI: 10.1002/ar.22576] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Accepted: 07/24/2012] [Indexed: 12/20/2022]
Abstract
This review addresses the current status of steroid therapies for hearing and vestibular disorders and how certain misconceptions may be undermining the efficacy in restoring normal ear function, both experimentally and clinically. Specific misconceptions addressed are that steroid therapy is not effective, steroid-responsive hearing loss proves an underlying inflammatory problem in the ear, and steroids only have application to the hearing disorders listed below. Glucocorticoid therapy for hearing and balance disorders has been employed for over 60 years. It is recommended in cases of sudden hearing loss, Meniére's disease, immune-mediated hearing loss, and any vestibular dysfunction suspected of having an inflammatory etiology. The predominant steroids employed today are dexamethasone, prednisone, prednisolone, and methylprednisolone. Despite years of use, little is known of the steroid responsive mechanisms in the ear that are influenced by glucocorticoid therapy. Furthermore, meta-analyses and clinical study reviews occasionally question whether steroids offer any benefit at all. Foremost in the minds of clinicians is the immune suppression and anti-inflammatory functions of steroids because of their efficacy for autoimmune hearing loss. However, glucocorticoids have a strong binding affinity for the mineralocorticoid (aldosterone) and glucocorticoid receptors, both of which are prominent in the ear. Because the auditory and vestibular end organs require tightly regulated endolymph and perilymph fluids, this ion homeostasis role of the mineralocorticoid receptor cannot be overlooked in both normal and pathologic functions of the ear. The function of the glucocorticoid receptor is to provide anti-inflammatory and antiapoptotic signals by mediating survival factors.
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Charitidi K, Meltser I, Canlon B. Estradiol treatment and hormonal fluctuations during the estrous cycle modulate the expression of estrogen receptors in the auditory system and the prepulse inhibition of acoustic startle response. Endocrinology 2012; 153:4412-21. [PMID: 22778224 DOI: 10.1210/en.2012-1416] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Estrogens' effects on hearing are documented across species, but the responsible molecular mechanisms remain unknown. The presence of estrogen receptors (ER) throughout the auditory system offers a potential pathway of direct estrogenic effects on auditory function, but little is known about how each ER's expression is regulated by the overall hormonal status of the body. In the present study, we determined the effects of ovariectomy and chronic 17β-estradiol treatment on mRNA and protein expression of ERα and ERβ in peripheral (cochlea) and central (inferior colliculus) auditory structures of mice, as well as on auditory-related behavior using the acoustic startle response (ASR), prepulse inhibition (PPI), and habituation of the startle response. 17β-Estradiol treatment down-regulated ERα but not ERβ and increased PPI and latency of the ASR. Neither the magnitude nor the habituation of ASR was affected. Furthermore, ER's mRNA and protein expression in the inner ear were analyzed throughout the estrous cycle (proestrus, estrus, metestrus, and diestrus), revealing a negative correlation of circulating estrogens with ERα expression, whereas ERβ was stable. Our findings show that ER not only are present in both the peripheral and central auditory system but also that circulating estrogen levels down-regulate ERα expression in the auditory system and affect PPI and the latency of ASR, suggesting a key role of ERα as a hormone-induced modulator of the auditory system and behavior.
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Wallén MB, Hasson D, Theorell T, Canlon B. The correlation between the hyperacusis questionnaire and uncomfortable loudness levels is dependent on emotional exhaustion. Int J Audiol 2012; 51:722-9. [DOI: 10.3109/14992027.2012.695874] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Sekiya T, Viberg A, Kojima K, Sakamoto T, Nakagawa T, Ito J, Canlon B. Trauma-specific insults to the cochlear nucleus in the rat. J Neurosci Res 2012; 90:1924-31. [PMID: 22715005 DOI: 10.1002/jnr.23093] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2011] [Revised: 03/27/2012] [Accepted: 05/07/2012] [Indexed: 12/19/2022]
Abstract
The effect of acoustic overstimulation on the neuronal number of the cochlear nucleus (CN) was investigated by using unbiased stereological methods in rats. We found that, after 9 weeks of recovery, neurons in the anteroventral cochlear nucleus (AVCN) degenerated, whereas those in the posteroventral and dorsal cochlear nuclei (PVCN and DCN) were preserved. The noise trauma induced near complete loss of the outer hair cells throughout the cochlea, and the inner hair cells were preserved only in the more apical regions. This pattern of selective loss of AVCN neurons in this study was different from trauma induced by auditory deafferentation by mechanical compression of auditory neurons. In contrast to noise trauma, mechanical compression caused loss of neurons in the PVCN and DCN. After 5 weeks of recovery from mechanical compression, there was no loss of inner or outer hair cells. These findings indicate that auditory deprivation, induced by different experimental manipulations, can have strikingly different consequences for the central auditory system. We hypothesized that AVCN neuronal death was induced by excitotoxic mechanisms via AMPA-type glutamate receptors and that excitatory neuronal circuits developed after acoustic overstimulation protected the PVCN and DCN against neuronal death. The results of the present study demonstrate that hearing loss from different etiologies will cause different patterns of neuronal degeneration in the CN. These findings are important for enhancing the performance of cochlear implants and auditory brainstem implants, because diverse types of hearing loss can selectively affect neuronal degeneration of the CN.
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Canlon B. Introduction to Annual Reviews 2012. Hear Res 2012. [DOI: 10.1016/j.heares.2012.05.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Kraus KS, Canlon B. Neuronal connectivity and interactions between the auditory and limbic systems. Effects of noise and tinnitus. Hear Res 2012; 288:34-46. [DOI: 10.1016/j.heares.2012.02.009] [Citation(s) in RCA: 162] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2011] [Revised: 12/09/2011] [Accepted: 02/22/2012] [Indexed: 01/01/2023]
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Hébert S, Canlon B, Hasson D, Magnusson Hanson LL, Westerlund H, Theorell T. Tinnitus severity is reduced with reduction of depressive mood--a prospective population study in Sweden. PLoS One 2012; 7:e37733. [PMID: 22629449 PMCID: PMC3358289 DOI: 10.1371/journal.pone.0037733] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2012] [Accepted: 04/23/2012] [Indexed: 11/18/2022] Open
Abstract
Tinnitus, the perception of sound without external source, is a highly prevalent public health problem with about 8% of the population having frequently occurring tinnitus, and about 1-2% experiencing significant distress from it. Population studies, as well as studies on self-selected samples, have reported poor psychological well-being in individuals with tinnitus. However, no study has examined the long-term co-variation between mood and tinnitus prevalence or tinnitus severity. In this study, the relationship between depression and tinnitus prevalence and severity over a 2-year period was examined in a representative sample of the general Swedish working population. Results show that a decrease in depression is associated with a decrease in tinnitus prevalence, and even more markedly with tinnitus severity. Hearing loss was a more potent predictor than depression for tinnitus prevalence, but was a weaker predictor than depression for tinnitus severity. In addition, there were sex differences for tinnitus prevalence, but not for tinnitus severity. This study shows a direct and long-term association between tinnitus severity and depression.
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Fisahn A, Lavebratt C, Canlon B. Acoustic startle hypersensitivity in Mceph mice and its effect on hippocampal excitability. Eur J Neurosci 2012; 34:1121-30. [PMID: 21966978 DOI: 10.1111/j.1460-9568.2011.07834.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Current therapies and research for epilepsy concentrate mainly on controlling the disease, but not on prevention of its development and progression. This is partly due to the under-appreciated heterogeneity of the different epileptic syndromes, and a lack of knowledge about the underlying mechanisms of hypersensitivity and hypersynchrony in epilepsy development and spread. In this study we investigate mechanisms underlying the increased susceptibility to acoustic startle in a mouse model homozygous for the spontaneous megencephaly (mceph) mutation, which results in a lack of the functional potassium channel Kv1.1. Mceph mice are hypersensitive to acoustic startle, a response that is not seen in the wild-type (WT) littermates. After acoustic startle, a strong activation of astrocytes, as indicated by glial fibrillary acidic protein, occurred in the inferior colliculus and hippocampus. Both the hypersensitivity of acoustic startle as well as activation of astrocytes could be maintained at WT levels by pre-treating the Mceph mice with the anti-epileptic drug valproate. Furthermore, we utilized the Mceph mouse model to investigate whether acoustic startle-induced hypersensitivity has negative consequences for synchronous neuronal activity in other, non-auditory, systems and networks in the brain, such as the hippocampus. Our findings show that acoustic startle-induced hypersensitivity primes hippocampal networks by increasing their excitability, which results in increased strength of rhythmic network activity. Our results provide novel insights into the mechanisms that underlie the spread of hypersensitivity and hypersynchrony across functionally different parts of the brain.
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Ashmore J, Avan P, Brownell W, Dallos P, Dierkes K, Fettiplace R, Grosh K, Hackney C, Hudspeth A, Jülicher F, Lindner B, Martin P, Meaud J, Petit C, Santos-Sacchi J, Canlon B. Corrigendum to “The remarkable cochlear amplifier” [Hear. Res. 266 (1–2) (2010) 1–17]. Hear Res 2011. [DOI: 10.1016/j.heares.2011.05.020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Alagic Z, Goiny M, Canlon B. Protection against acoustic trauma by direct application of D-methionine to the inner ear. Acta Otolaryngol 2011; 131:802-8. [PMID: 21480759 DOI: 10.3109/00016489.2011.564652] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
CONCLUSION The findings from this study extend the use of the local application of D-methionine (D-met) to protect against acoustic trauma and demonstrate that D-met slowly diffuses from the perilymph. OBJECTIVES The objectives of the study were to determine the effect of D-met on auditory function and morphology after acoustic trauma and to measure the concentration of D-met in perilymph. METHODS Auditory thresholds were determine before, immediately after, and 24 h after acoustic trauma. Cochleae were analyzed using immunocytochemistry for c-Fos, TUJI, and cytochrome c. The concentration of D-met was determined from perilymph. RESULTS Protection against acoustic trauma (immediately and 24 h post trauma) on auditory brainstem thresholds was found at a time when the concentration of D-met in perilymph showed a fivefold increase above basal levels. The local application of D-met to the guinea pig cochlea results in elevated D-met concentrations that are maintained in the perilymph for at least 24 h.
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Wallén MB, Hasson D, Theorell T, Canlon B, Osika W. Possibilities and limitations of the polar RS800 in measuring heart rate variability at rest. Eur J Appl Physiol 2011; 112:1153-65. [DOI: 10.1007/s00421-011-2079-9] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2011] [Accepted: 07/05/2011] [Indexed: 12/29/2022]
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Meltser I, Canlon B. Protecting the auditory system with glucocorticoids. Hear Res 2011; 281:47-55. [PMID: 21718769 DOI: 10.1016/j.heares.2011.06.003] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2011] [Revised: 06/07/2011] [Accepted: 06/09/2011] [Indexed: 01/03/2023]
Abstract
Glucocorticoids are hormones released following stress-related events and function to maintain homeostasis. Glucocorticoid receptors localize, among others, to hair cells, spiral ligament and spiral ganglion neurons. Glucocorticoid receptor-induced protection against acoustic trauma is found by i) pretreatment with glucocorticoid agonists; ii) acute restraint stress; and iii) sound conditioning. In contrast, glucocorticoid receptor antagonists exacerbate hearing loss. These findings have important clinical significance since synthetic glucocorticoids are commonly used to treat hearing loss. However, this treatment has limited success since hearing improvement is often not maintained once the treatment has ended, a fact that reduces the overall appeal for this treatment. It must be realized that despite the widespread use of glucocorticoids to treat hearing disorders, the molecular mechanisms underlying this treatment are not well characterized. This review will give insight into some physiological and biochemical mechanisms underlying glucocorticoid treatment for preventing hearing loss.
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Hasson D, Theorell T, Wallén MB, Leineweber C, Canlon B. Stress and prevalence of hearing problems in the Swedish working population. BMC Public Health 2011; 11:130. [PMID: 21345187 PMCID: PMC3056746 DOI: 10.1186/1471-2458-11-130] [Citation(s) in RCA: 109] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2010] [Accepted: 02/23/2011] [Indexed: 01/15/2023] Open
Abstract
Background Current human and experimental studies are indicating an association between stress and hearing problems; however potential risk factors have not been established. Hearing problems are projected to become among the top ten disabilities according to the WHO in the near future. Therefore a better understanding of the relationships between stress and hearing is warranted. Here we describe the prevalence of two common hearing problems, i.e. hearing complaints and tinnitus, in relation to different work-and health-related stressors. Methods A total of 18,734 individuals were invited to participate in the study, out of which 9,756 (52%) enrolled. Results The results demonstrate a clear and mostly linear relationship between higher prevalence of hearing problems (tinnitus or hearing loss or both) and different stressors, e.g. occupational, poorer self-rated health, long-term illness, poorer sleep quality, and higher burnout scores. Conclusions The present study unambiguously demonstrates associations between hearing problems and various stressors that have not been previously described for the auditory system. These findings will open new avenues for future investigations.
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