Zoology/Biology session

Hearing losses are the most prevalent sensory disorder. The hearing organ of Corti is located in a bony capsule in the pars petrosa of the temporal bone. Its spiraling morfology makes it difficult to ivestigate the cellular mechanism of hearing. The supporting cells near the hair cells are equally important in proper hearing, however they receive little attention. One type of the supporting cells are the Deiters cells which are in close connection with the outer hair cells, and therefore may influence their development, regeneration and the hearing threshold. The preparation of these cells is difficult because of the bony structure, so most researches work with mice no older than three weeks, when ossification is not complete. On the other hand, young mice do not respond to external sounds before two weeks of age, hence results before day 14 may not be representative of the hearing of adult mice.

Matematical modells could replace the difficult preparation, but there are no modells for the supporting cells. My aim was to test and modify a general mathematical modell (originally set up for astrocytes) for the Deiters cells, which could relaibly describe their calcium handling mechanis. To validate the modell I used funcional calcium imaging recordings of Deiters cells from mice (day 15, BALB/c, n=34, turns: basal, middle, apical, induced with 100 μM ATP). To find the best describing parameter combination I tested approximately 800 000 parameter sets. The matemathical modell is suitable for predicting the calcium transients of the Deiters cells in the major part of the hearing organ and hence could be a good start to establish a more detailed modell for these cells. In addition it may help the development of this research area.