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Siveke I, Myoga MH, Grothe B, Felmy F. Ambient noise exposure induces long-term adaptations in adult brainstem neurons. Sci Rep 2021; 11:5139. [PMID: 33664302 PMCID: PMC7933235 DOI: 10.1038/s41598-021-84230-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 02/12/2021] [Indexed: 11/09/2022] Open
Abstract
To counterbalance long-term environmental changes, neuronal circuits adapt the processing of sensory information. In the auditory system, ongoing background noise drives long-lasting adaptive mechanism in binaural coincidence detector neurons in the superior olive. However, the compensatory cellular mechanisms of the binaural neurons in the medial superior olive (MSO) to long-term background changes are unexplored. Here we investigated the cellular properties of MSO neurons during long-lasting adaptations induced by moderate omnidirectional noise exposure. After noise exposure, the input resistance of MSO neurons of mature Mongolian gerbils was reduced, likely due to an upregulation of hyperpolarisation-activated cation and low voltage-activated potassium currents. Functionally, the long-lasting adaptations increased the action potential current threshold and facilitated high frequency output generation. Noise exposure accelerated the occurrence of spontaneous postsynaptic currents. Together, our data suggest that cellular adaptations in coincidence detector neurons of the MSO to continuous noise exposure likely increase the sensitivity to differences in sound pressure levels.
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Affiliation(s)
- Ida Siveke
- Division of Neurobiology, Department Biology II, Ludwig-Maximilians-University Munich, 82152, Planegg-Martinsried, Germany. .,Institute of Zoology and Neurobiology, Ruhr-University Bochum, Universitätsstrasse 150, 44780, Bochum, Germany.
| | - Mike H Myoga
- Division of Neurobiology, Department Biology II, Ludwig-Maximilians-University Munich, 82152, Planegg-Martinsried, Germany
| | - Benedikt Grothe
- Division of Neurobiology, Department Biology II, Ludwig-Maximilians-University Munich, 82152, Planegg-Martinsried, Germany
| | - Felix Felmy
- Division of Neurobiology, Department Biology II, Ludwig-Maximilians-University Munich, 82152, Planegg-Martinsried, Germany. .,Institute of Zoology, University of Veterinary Medicine Hannover, Foundation, Bünteweg 17, 30599, Hannover, Germany.
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Siveke I, Lingner A, Ammer JJ, Gleiss SA, Grothe B, Felmy F. A Temporal Filter for Binaural Hearing Is Dynamically Adjusted by Sound Pressure Level. Front Neural Circuits 2019; 13:8. [PMID: 30814933 PMCID: PMC6381077 DOI: 10.3389/fncir.2019.00008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Accepted: 01/24/2019] [Indexed: 12/02/2022] Open
Abstract
In natural environments our auditory system is exposed to multiple and diverse signals of fluctuating amplitudes. Therefore, to detect, localize, and single out individual sounds the auditory system has to process and filter spectral and temporal information from both ears. It is known that the overall sound pressure level affects sensory signal transduction and therefore the temporal response pattern of auditory neurons. We hypothesize that the mammalian binaural system utilizes a dynamic mechanism to adjust the temporal filters in neuronal circuits to different overall sound pressure levels. Previous studies proposed an inhibitory mechanism generated by the reciprocally coupled dorsal nuclei of the lateral lemniscus (DNLL) as a temporal neuronal-network filter that suppresses rapid binaural fluctuations. Here we investigated the consequence of different sound levels on this filter during binaural processing. Our in vivo and in vitro electrophysiology in Mongolian gerbils shows that the integration of ascending excitation and contralateral inhibition defines the temporal properties of this inhibitory filter. The time course of this filter depends on the synaptic drive, which is modulated by the overall sound pressure level and N-methyl-D-aspartate receptor (NMDAR) signaling. In psychophysical experiments we tested the temporal perception of humans and show that detection and localization of two subsequent tones changes with the sound pressure level consistent with our physiological results. Together our data support the hypothesis that mammals dynamically adjust their time window for sound detection and localization within the binaural system in a sound level dependent manner.
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Affiliation(s)
- Ida Siveke
- Department Biology II, Division of Neurobiology, Ludwig-Maximilians-Universität München, Munich, Germany.,Institute of Zoology and Neurobiology, Ruhr-Universität Bochum, Bochum, Germany
| | - Andrea Lingner
- Department Biology II, Division of Neurobiology, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Julian J Ammer
- Department Biology II, Division of Neurobiology, Ludwig-Maximilians-Universität München, Munich, Germany.,Graduate School for Systemic Neurosciences, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Sarah A Gleiss
- Department Biology II, Division of Neurobiology, Ludwig-Maximilians-Universität München, Munich, Germany.,Graduate School for Systemic Neurosciences, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Benedikt Grothe
- Department Biology II, Division of Neurobiology, Ludwig-Maximilians-Universität München, Munich, Germany.,Graduate School for Systemic Neurosciences, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Felix Felmy
- Department Biology II, Division of Neurobiology, Ludwig-Maximilians-Universität München, Munich, Germany.,Institute of Zoology, University of Veterinary Medicine Hannover, Hannover, Germany
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3
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Siveke I, Ammer JJ, Gleiss SA, Grothe B, Leibold C, Felmy F. Electrogenic N-methyl-D-aspartate receptor signaling enhances binaural responses in the adult brainstem. Eur J Neurosci 2018; 47:858-865. [PMID: 29405453 DOI: 10.1111/ejn.13859] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 01/30/2018] [Accepted: 01/30/2018] [Indexed: 01/29/2023]
Abstract
In sensory systems, the neuronal representation of external stimuli is enhanced along the sensory pathway. In the auditory system, strong enhancement of binaural information takes place between the brainstem and the midbrain; however, the underlying cellular mechanisms are unknown. Here we investigated the transformation of binaural information in the dorsal nucleus of the lateral lemniscus (DNLL), a nucleus that connects the binaural nuclei in the brainstem and the inferior colliculus in the midbrain. We used in vitro and in vivo electrophysiology in adult Mongolian gerbils to show that N-methyl-D-aspartate receptor (NMDARs) play a critical role in neuronal encoding of stimulus properties in the DNLL. While NMDARs increase firing rates, the timing and the accuracy of the neuronal responses remain unchanged. NMDAR-mediated excitation increases the information about the acoustic stimulus. Taken together, our results show that NMDARs in the DNLL enhance the auditory information content in adult mammal brainstem.
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Affiliation(s)
- Ida Siveke
- Division of Neurobiology, Department Biology II, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany.,Institute of Zoology and Neurobiology, Ruhr-Universität Bochum, 44780, Bochum, Germany
| | - Julian J Ammer
- Division of Neurobiology, Department Biology II, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany.,Centre for Integrative Physiology, Edinburgh Medical School: Biomedical Sciences, University of Edinburgh, Edinburgh, UK
| | - Sarah A Gleiss
- Division of Neurobiology, Department Biology II, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany.,Graduate School for Systemic Neurosciences, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
| | - Benedikt Grothe
- Division of Neurobiology, Department Biology II, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany.,Graduate School for Systemic Neurosciences, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
| | - Christian Leibold
- Computational Neuroscience, Department Biology II, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
| | - Felix Felmy
- Division of Neurobiology, Department Biology II, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany.,Institute of Zoology, University of Veterinary Medicine Hannover, 30599, Hannover, Germany
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Agarwal M, Ulmer JL, Klein AP, Mark LP. Cortical and Subcortical Substrates of Cranial Nerve Function. Semin Ultrasound CT MR 2015; 36:275-90. [PMID: 26233861 DOI: 10.1053/j.sult.2015.05.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The pivotal role of cranial nerves in a wholesome life experience cannot be overemphasized. Research has opened new avenues to understand cranial nerve function. Classical concept of strict bilateral cortical control of cranial nerves has given way to concepts of hemispheric dominance and hemispheric lateralization. An astute Neuroradiologist should keep abreast of these concepts and help patients and referring physicians by applying this knowledge in reading images. This chapter provides an overview of cranial nerve function and latest concepts pertaining to their cortical and subcortical control.
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Affiliation(s)
- Mohit Agarwal
- Department of Radiology, Medical College of Wisconsin, Milwaukee, WI.
| | - John L Ulmer
- Department of Radiology, Medical College of Wisconsin, Milwaukee, WI
| | - Andrew P Klein
- Department of Radiology, Medical College of Wisconsin, Milwaukee, WI
| | - Leighton P Mark
- Department of Radiology, Medical College of Wisconsin, Milwaukee, WI
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Leibold C, Grothe B. Sound localization with microsecond precision in mammals: what is it we do not understand? ACTA ACUST UNITED AC 2015. [DOI: 10.1007/s13295-015-0001-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Action potential generation in an anatomically constrained model of medial superior olive axons. J Neurosci 2014; 34:5370-84. [PMID: 24719114 DOI: 10.1523/jneurosci.4038-13.2014] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Neurons in the medial superior olive (MSO) encode interaural time differences (ITDs) with sustained firing rates of >100 Hz. They are able to generate such high firing rates for several hundred milliseconds despite their extremely low-input resistances of only few megaohms and high synaptic conductances in vivo. The biophysical mechanisms by which these leaky neurons maintain their excitability are not understood. Since action potentials (APs) are usually assumed to be generated in the axon initial segment (AIS), we analyzed anatomical data of proximal MSO axons in Mongolian gerbils and found that the axon diameter is <1 μm and the internode length is ∼100 μm. Using a morphologically constrained computational model of the MSO axon, we show that these thin axons facilitate the excitability of the AIS. However, for ongoing high rates of synaptic inputs the model generates a substantial fraction of APs in its nodes of Ranvier. These distally initiated APs are mediated by a spatial gradient of sodium channel inactivation and a strong somatic current sink. The model also predicts that distal AP initiation increases the dynamic range of the rate code for ITDs.
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Glycinergic inhibition tunes coincidence detection in the auditory brainstem. Nat Commun 2014; 5:3790. [PMID: 24804642 PMCID: PMC4024823 DOI: 10.1038/ncomms4790] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Accepted: 04/02/2014] [Indexed: 11/30/2022] Open
Abstract
Neurons in the medial superior olive (MSO) detect microsecond differences in the arrival time of sounds between the ears (interaural time differences or ITDs), a crucial binaural cue for sound localization. Synaptic inhibition has been implicated in tuning ITD sensitivity, but the cellular mechanisms underlying its influence on coincidence detection are debated. Here we determine the impact of inhibition on coincidence detection in adult Mongolian gerbil MSO brain slices by testing precise temporal integration of measured synaptic responses using conductance-clamp. We find that inhibition dynamically shifts the peak timing of excitation, depending on its relative arrival time, which in turn modulates the timing of best coincidence detection. Inhibitory control of coincidence detection timing is consistent with the diversity of ITD functions observed in vivo and is robust under physiologically relevant conditions. Our results provide strong evidence that temporal interactions between excitation and inhibition on microsecond timescales are critical for binaural processing. Coincidence detector neurons in the mammalian brainstem encode interaural time differences (ITDs) that are implicated in auditory processing. Myoga et al. study a previously developed neuronal model and find that inhibition is crucial for sound localization, but more dynamically than previously thought.
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Stange A, Myoga MH, Lingner A, Ford MC, Alexandrova O, Felmy F, Pecka M, Siveke I, Grothe B. Adaptation in sound localization: from GABA(B) receptor-mediated synaptic modulation to perception. Nat Neurosci 2013; 16:1840-7. [PMID: 24141311 DOI: 10.1038/nn.3548] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Accepted: 09/17/2013] [Indexed: 11/09/2022]
Abstract
Across all sensory modalities, the effect of context-dependent neural adaptation can be observed at every level, from receptors to perception. Nonetheless, it has long been assumed that the processing of interaural time differences, which is the primary cue for sound localization, is nonadaptive, as its outputs are mapped directly onto a hard-wired representation of space. Here we present evidence derived from in vitro and in vivo experiments in gerbils indicating that the coincidence-detector neurons in the medial superior olive modulate their sensitivity to interaural time differences through a rapid, GABA(B) receptor-mediated feedback mechanism. We show that this mechanism provides a gain control in the form of output normalization, which influences the neuronal population code of auditory space. Furthermore, psychophysical tests showed that the paradigm used to evoke neuronal GABA(B) receptor-mediated adaptation causes the perceptual shift in sound localization in humans that was expected on the basis of our physiological results in gerbils.
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Affiliation(s)
- Annette Stange
- Division of Neurobiology, Department Biologie II, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
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Seidl AH. Regulation of conduction time along axons. Neuroscience 2013; 276:126-34. [PMID: 23820043 DOI: 10.1016/j.neuroscience.2013.06.047] [Citation(s) in RCA: 128] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Revised: 06/13/2013] [Accepted: 06/17/2013] [Indexed: 11/17/2022]
Abstract
Timely delivery of information is essential for proper functioning of the nervous system. Precise regulation of nerve conduction velocity is needed for correct exertion of motor skills, sensory integration and cognitive functions. In vertebrates, the rapid transmission of signals along nerve fibers is made possible by the myelination of axons and the resulting saltatory conduction in between nodes of Ranvier. Myelin is a specialization of glia cells and is provided by oligodendrocytes in the central nervous system. Myelination not only maximizes conduction velocity, but also provides a means to systematically regulate conduction times in the nervous system. Systematic regulation of conduction velocity along axons, and thus systematic regulation of conduction time in between neural areas, is a common occurrence in the nervous system. To date, little is understood about the mechanism that underlies systematic conduction velocity regulation and conduction time synchrony. Node assembly, internode distance (node spacing) and axon diameter - all parameters determining the speed of signal propagation along axons - are controlled by myelinating glia. Therefore, an interaction between glial cells and neurons has been suggested. This review summarizes examples of neural systems in which conduction velocity is regulated by anatomical variations along axons. While functional implications in these systems are not always clear, recent studies on the auditory system of birds and mammals present examples of conduction velocity regulation in systems with high temporal precision and a defined biological function. Together these findings suggest an active process that shapes the interaction between axons and myelinating glia to control conduction velocity along axons. Future studies involving these systems may provide further insight into how specific conduction times in the brain are established and maintained in development. Throughout the text, conduction velocity is used for the speed of signal propagation, i.e. the speed at which an action potential travels. Conduction time refers to the time it takes for a specific signal to travel from its origin to its target, i.e. neuronal cell body to axonal terminal.
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Affiliation(s)
- A H Seidl
- Virginia Merrill Bloedel Hearing Research Center, University of Washington, Seattle, WA, USA; Department of Otolaryngology - Head & Neck Surgery, University of Washington, Seattle, WA, USA.
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Hancock KE, Chung Y, Delgutte B. Congenital and prolonged adult-onset deafness cause distinct degradations in neural ITD coding with bilateral cochlear implants. J Assoc Res Otolaryngol 2013; 14:393-411. [PMID: 23462803 PMCID: PMC3642270 DOI: 10.1007/s10162-013-0380-5] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2012] [Accepted: 02/15/2013] [Indexed: 10/27/2022] Open
Abstract
Bilateral cochlear implant (CI) users perform poorly on tasks involving interaural time differences (ITD), which are critical for sound localization and speech reception in noise by normal-hearing listeners. ITD perception with bilateral CI is influenced by age at onset of deafness and duration of deafness. We previously showed that ITD coding in the auditory midbrain is degraded in congenitally deaf white cats (DWC) compared to acutely deafened cats (ADC) with normal auditory development (Hancock et al., J. Neurosci, 30:14068). To determine the relative importance of early onset of deafness and prolonged duration of deafness for abnormal ITD coding in DWC, we recorded from single units in the inferior colliculus of cats deafened as adults 6 months prior to experimentation (long-term deafened cats, LTDC) and compared neural ITD coding between the three deafness models. The incidence of ITD-sensitive neurons was similar in both groups with normal auditory development (LTDC and ADC), but significantly diminished in DWC. In contrast, both groups that experienced prolonged deafness (LTDC and DWC) had broad distributions of best ITDs around the midline, unlike the more focused distributions biased toward contralateral-leading ITDs present in both ADC and normal-hearing animals. The lack of contralateral bias in LTDC and DWC results in reduced sensitivity to changes in ITD within the natural range. The finding that early onset of deafness more severely degrades neural ITD coding than prolonged duration of deafness argues for the importance of fitting deaf children with sound processors that provide reliable ITD cues at an early age.
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Affiliation(s)
- Kenneth E. Hancock
- />Eaton-Peabody Laboratories, Massachusetts Eye & Ear Infirmary, Boston, MA 02114 USA
- />Department of Otology and Laryngology, Harvard Medical School, Boston, MA 02115 USA
| | - Yoojin Chung
- />Eaton-Peabody Laboratories, Massachusetts Eye & Ear Infirmary, Boston, MA 02114 USA
- />Department of Otology and Laryngology, Harvard Medical School, Boston, MA 02115 USA
| | - Bertrand Delgutte
- />Eaton-Peabody Laboratories, Massachusetts Eye & Ear Infirmary, Boston, MA 02114 USA
- />Department of Otology and Laryngology, Harvard Medical School, Boston, MA 02115 USA
- />Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA 02139 USA
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Furukawa S, Washizawa S, Ochi A, Kashino M. How independent are the pitch and interaural-time-difference mechanisms that rely on temporal fine structure information? ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2013; 787:91-9. [PMID: 23716213 DOI: 10.1007/978-1-4614-1590-9_11] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The temporal fine structure (TFS) of acoustical signals, represented as the phase-locking pattern of the auditory nerve, is the major information for listeners performing a variety of auditory tasks, e.g., judging pitch and detecting interaural time differences (ITDs). Two experiments tested the hypothesis that processes for TFS-based pitch and ITD involve a common mechanism that processes TFS information and the efficiency of the common mechanism determines the performance of the two tasks. The first experiment measured the thresholds for detecting TFS-based pitch shifts (Moore and Moore, J Acoust Soc Am 113:977-985, 2003) and for detecting ITD for a group of normal-hearing listeners. The detection thresholds for level increments and for interaural level differences were also measured. The stimulus was a harmonic complex (F0 = 100 Hz) that was spectrally shaped for the frequency region around the 11th harmonic. We expected a positive correlation between the pitch and ITD thresholds, based on the hypothesis that a common TFS mechanism plays a determinant role. We failed to find evidence for a positive correlation, hence no support for the above hypothesis. The second experiment examined whether perceptual learning with respect to detecting TFS-based pitch shifts via training would transfer to performance in other untrained tasks. The stimuli and tasks were the same as those used in the first experiment. Generally, training in the pitch task improved performance in the (trained) pitch task, but degraded the performance in the (untrained) ITD task, which was unexpected on the basis of the hypothesis. No training effect was observed in the other untrained tasks. The results imply that the pitch and ITD processes compete with each other for limited neural resources.
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Affiliation(s)
- Shigeto Furukawa
- NTT Communication Science Laboratories, NTT Corporation, Kanagawa, Japan.
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Faulkner KF, Pisoni DB. Some observations about cochlear implants: challenges and future directions. ACTA ACUST UNITED AC 2013. [DOI: 10.7243/2052-6946-1-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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