Histological structure of Nannospalax xanthodon cochlea tissue

Because of the growth retardation in the eyes of Nannospalax xanthodon blind mole rat, some genetic and environmental adaptations have occurred in the smelling and hearing systems so that they can communicate efficiently in the galleries underground. This study was aimed to determine the histological and morphometric structure of the unique organization of the cochlea, which plays an important role in hearing in N. xanthodon . After the decalcification process, the cochlear tissue was cut in 5 μm thickness after routine histological procedures. Then these sections stained with Hematoxylin & Eosin and Masson trichrome methods were examined histologically. Besides, the data obtained by taking measurements with the Image J program in the basal, media, and apex regions of the cochlea were evaluated statistically. It was observed that basilar membrane length, tectorial membrane length, stria vascularis thickness, and inner-outer hair cell lengths increased, while Reissner’s membrane length and basilar membrane thickness decreased. These data show that the general histological structure of the blind mole rat cochlea is similar to that of other mammals. By evaluating histomorphological findings, it was concluded that cochlea, which plays a primary role in hearing with the effect of living conditions and genetic structures, develops better in blind mole rats than other living species.