Ultrastructure of hair cells of the organ of Corti and the effects of minocycline on responses to acustic stimulation in a mouse model of fragile X syndrome

The mechanisms underlying the disturbance of the response to acoustic signals in patients with fragile X (FXS) syndrome are very poorly understood. At the same time, it is known that children suffering from FXS exhibit hypersensitivity to auditory stimuli. Sensory cells (inner hair cells) grouped in the organ of Corti play the key role in the processing of auditory information. Preliminary results of our research with the use of mice deficient in Fmr1 gene expression (Fmr1 KO) indicate morphological changes in the synaptic layer of the hair cells. Since this is the first synaptic connection from sensory cells to the brain, we hypothesize that the differences in synapse structure that we observed can at least partly account for disturbances in sound reception in FXS. The main objectives of the project are to analyze the morphology and ultrastructure of hair cells, to check the effect of minocycline on potential defects in the morphology of these cells and to evaluate changes in the processing of auditory stimuli by means of electrophysiology in vivo.