BioProject

Presbycusis – age-related hearing loss – is the number one communicative disorder of our aged population. More...

Presbycusis – age-related hearing loss – is the number one communicative disorder of our aged population. Here we analyzed gene expression for a set of GABA receptors in the cochlea of aging CBA mice using the Affymetrix GeneChip MOE430A. Functional phenotypic hearing measures distortion-product otoacoustic emission (DPOAE) amplitudes (four age groups) were made. The gene expression changes from RMA normalized microarray data (40 replicates) were first subjected to one-way ANOVA, and then linear regression was performed. In addition, the log signal ratio was converted to fold change, and selected gene expression changes were confirmed by relative real-time PCR. Major findings: expression of GABA-A receptor subunit 6was upregulated with age and hearing loss, whereas subunit 1 was repressed. In addition, GABA-A receptor associated protein like-1 and GABA-A receptor associated protein like-2 were strongly downregulated with age and hearing impairment. Lastly, gene expression measures were correlated with pathway/network relationships relevant to the inner ear using Pathway Architect, to identify key pathways consistent with the gene expression changes observed. Overall design: In the study of expression changes GABA receptors in the in cochlea of young adult and aging presbycusis mice total of forty chips were used. The normal aging mice were in four groups young adults controls with good hearing (8 mice, 8 MOE430A GeneChips), Middle aged group with good hearing ( 17 mice, 17 MOE430A GeneChips), Mild Presbycusis (old) with limited hearing loss (9 mice, 9 MOE430A GeneChips) and Severe Presbycusis (old) (6 mice, 6 MOE430A GeneChips). Each Mice cochlea to each GeneChips, Samples was not pooled. The hearing potential evidence of each mouse is accompanied with each mice DPOAE amplitude. Less...