Do mechanického modelu kochley zavádzame implicitné numerické metódy. Tes- tujeme konkrétne štyri metódy: implicitný Euler, Crank-Nicolson, BDF druhého a tretieho rádu na lineárnej a nelineárnej verzii modelu. Nelineárny model obsahuje funkciu so saturujúcou vlastnosťou. Aplikácia implicitných metód na nelineárny model vedie na sústavu nelineárnych rovníc. Predstavujeme dva spôsoby, ako túto sústavu numericky riešiť. Prvý z nich zahrňuje nelinearitu do pravej strany novovzniknutej lineárnej sústavy. Druhý robí linearizáciu nelineárnej funkcie. V práci porovnávame oba spôsoby z hľadiska efektivity a sledujeme ich konvergenciu k referenčnému riešeniu. Pre hodnotu tolerancie, ktorú používame na určenie numerickej konvergencie, je prvý spôsob efektívnejší. V úplne nelineárnom režime druhý spôsob zlyháva, pretože nekon- verguje k referenčnému riešeniu. Výsledkom porovnania implicitných metód je, že Crank-Nicolsonova metóda s prvým spôsobom riešenia nelineárnej sústavy je pre účely nášho modelu najlepšia. Použitie tejto metódy v mechanickom modeli nám umožňuje vytvoriť ľubovoľne presné prepojenie medzi mechanickým a elektrickým modelom kochley, rešpektujúc fyziológiu človeka. 1

Detailed knowledge of the role that particular genes and factors play during the development and in the normal function of the auditory system is necessary to develop successful regenerative inner ear therapies. Islet1 transcription factor and brain derived neurothrophic factor (BDNF) have great potential to play a role in regenerative inner ear therapy as both have been shown to be sufficient for self-repair regeneration in cochlea in animal studies. In this study we looked at the roles these two factors play in the development and function of the auditory system. In the transgenic mice used in the study, overexpression of Isl1 affected cell specification during embryonic development, leading to enlargement of the cochleovestibular ganglion and accelerated nerve fiber extension and branching in mutant embryos. The hearing of young transgenic mice was not affected. However, it started to decline in 1-month-old animals. This early onset of age-related hearing loss was found to be a consequence of the neurodegeneration of the olivocochlear system caused by Pax2-driven Isl1 misexpression in the hindbrain. Our data provide the first evidence that the alternation of the olivocochlear system efferent system accelerates the age-related functional decline of hearing without the loss of OHCs. The functional role of...

Detailed knowledge of the role that particular genes and factors play during the development and in the normal function of the auditory system is necessary to develop successful regenerative inner ear therapies. Islet1 transcription factor and brain derived neurothrophic factor (BDNF) have great potential to play a role in regenerative inner ear therapy as both have been shown to be sufficient for self-repair regeneration in cochlea in animal studies. In this study we looked at the roles these two factors play in the development and function of the auditory system. In the transgenic mice used in the study, overexpression of Isl1 affected cell specification during embryonic development, leading to enlargement of the cochleovestibular ganglion and accelerated nerve fiber extension and branching in mutant embryos. The hearing of young transgenic mice was not affected. However, it started to decline in 1-month-old animals. This early onset of age-related hearing loss was found to be a consequence of the neurodegeneration of the olivocochlear system caused by Pax2-driven Isl1 misexpression in the hindbrain. Our data provide the first evidence that the alternation of the olivocochlear system efferent system accelerates the age-related functional decline of hearing without the loss of OHCs. The functional role of...

No description available.