Investigation of auditory neuronal survival and outgrowth using a cochlear implant in an artificial cochlear model

Cochlear implants (CI) can restore hearing to people suffering from sensorineural hearing loss. The CI uses an array of electrodes inserted in the scala tympani to stimulate the spiral ganglion neurons (SGN), which are located in the bony axis of the inner ear. The spatial distance between the elect...

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Main Authors: Abdoul Tchadarou, Schwieger Jana, Lenarz Thomas, Nogueira Waldo, Scheper Verena
Format: Article
Language:English
Published: De Gruyter 2021-10-01
Series:Current Directions in Biomedical Engineering
Subjects:
Online Access:https://doi.org/10.1515/cdbme-2021-2114
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author Abdoul Tchadarou
Schwieger Jana
Lenarz Thomas
Nogueira Waldo
Scheper Verena
author_facet Abdoul Tchadarou
Schwieger Jana
Lenarz Thomas
Nogueira Waldo
Scheper Verena
author_sort Abdoul Tchadarou
collection DOAJ
description Cochlear implants (CI) can restore hearing to people suffering from sensorineural hearing loss. The CI uses an array of electrodes inserted in the scala tympani to stimulate the spiral ganglion neurons (SGN), which are located in the bony axis of the inner ear. The spatial distance between the electrodes and the SGN results in spread of excitation and unfocused stimulation. This distance could be bypassed by a neurite outgrowth towards the CI. In order to establish a culture system for the development of novel strategies for CI optimization, a neurite outgrowth chamber (NOC) allowing clinically relevant electrical stimulation paradigms was developed using fused deposition modelling. It was made out of biocompatible UV-curing silicone. The NOC was equipped with a slot to insert the electrode array into a scala tympani compartment whereas SGN isolated from postnatal rats were cultured in a neighbouring region mimicking the Rosenthal’s canal. Sound delivered through loudspeakers playing a radio program was captured by the CI sound processor, positioned outside the NOC, for 17 hours daily during a four-day period. The NOCs were tightly sealed and the electrode array could be positioned in the scala tympani compartment. The experimental setup allowed cell cultivation and the stimulation resulted in a significantly increased neurite length of around 36% while explant area and neurite number did not differ to the negative control (NC). A new in vitro testing system which considers the anatomy of the cochlea and clinic stimulation conditions has been developed and validated. The validation experiments resulted in increased neurite length. This indicates a progress in bridging the anatomical gap between electrode and stimulated neurons.
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spelling doaj.art-8d9643c9b646413fa378fd5bfebe30972022-12-22T04:35:04ZengDe GruyterCurrent Directions in Biomedical Engineering2364-55042021-10-017244945210.1515/cdbme-2021-2114Investigation of auditory neuronal survival and outgrowth using a cochlear implant in an artificial cochlear modelAbdoul Tchadarou0Schwieger Jana1Lenarz Thomas2Nogueira Waldo3Scheper Verena4Department of Sensors and Measurement Technology, Appelstraße 9A,Hannover, GermanyDepartment of Otolaryngology Hannover Medical School,Hannover, GermanyDepartment of Otolaryngology Hannover Medical School,Hannover, GermanyDepartment of Otolaryngology Hannover Medical School,Hannover, GermanyDepartment of Otolaryngology Hannover Medical School,Hannover, GermanyCochlear implants (CI) can restore hearing to people suffering from sensorineural hearing loss. The CI uses an array of electrodes inserted in the scala tympani to stimulate the spiral ganglion neurons (SGN), which are located in the bony axis of the inner ear. The spatial distance between the electrodes and the SGN results in spread of excitation and unfocused stimulation. This distance could be bypassed by a neurite outgrowth towards the CI. In order to establish a culture system for the development of novel strategies for CI optimization, a neurite outgrowth chamber (NOC) allowing clinically relevant electrical stimulation paradigms was developed using fused deposition modelling. It was made out of biocompatible UV-curing silicone. The NOC was equipped with a slot to insert the electrode array into a scala tympani compartment whereas SGN isolated from postnatal rats were cultured in a neighbouring region mimicking the Rosenthal’s canal. Sound delivered through loudspeakers playing a radio program was captured by the CI sound processor, positioned outside the NOC, for 17 hours daily during a four-day period. The NOCs were tightly sealed and the electrode array could be positioned in the scala tympani compartment. The experimental setup allowed cell cultivation and the stimulation resulted in a significantly increased neurite length of around 36% while explant area and neurite number did not differ to the negative control (NC). A new in vitro testing system which considers the anatomy of the cochlea and clinic stimulation conditions has been developed and validated. The validation experiments resulted in increased neurite length. This indicates a progress in bridging the anatomical gap between electrode and stimulated neurons.https://doi.org/10.1515/cdbme-2021-2114cochlear implantelectrical stimulationspiral ganglion neuroninner ear3d-printingneurite outgrowthelectrode neuron interfaceneuritogenesis
spellingShingle Abdoul Tchadarou
Schwieger Jana
Lenarz Thomas
Nogueira Waldo
Scheper Verena
Investigation of auditory neuronal survival and outgrowth using a cochlear implant in an artificial cochlear model
Current Directions in Biomedical Engineering
cochlear implant
electrical stimulation
spiral ganglion neuron
inner ear
3d-printing
neurite outgrowth
electrode neuron interface
neuritogenesis
title Investigation of auditory neuronal survival and outgrowth using a cochlear implant in an artificial cochlear model
title_full Investigation of auditory neuronal survival and outgrowth using a cochlear implant in an artificial cochlear model
title_fullStr Investigation of auditory neuronal survival and outgrowth using a cochlear implant in an artificial cochlear model
title_full_unstemmed Investigation of auditory neuronal survival and outgrowth using a cochlear implant in an artificial cochlear model
title_short Investigation of auditory neuronal survival and outgrowth using a cochlear implant in an artificial cochlear model
title_sort investigation of auditory neuronal survival and outgrowth using a cochlear implant in an artificial cochlear model
topic cochlear implant
electrical stimulation
spiral ganglion neuron
inner ear
3d-printing
neurite outgrowth
electrode neuron interface
neuritogenesis
url https://doi.org/10.1515/cdbme-2021-2114
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