The sensory epithelium and its innervation in the mole rat cochlea

The mole rat ( Spalax ehrenbergi ) burrows throughout its life in subterranean tunnels. Several structural and functional features which adapt the mole rat to its habitat have been discerned. The goal of this study was to elucidate the structural basis for adaptation of the auditory end-organ to an environment where low-frequency acoustical signals prevail. For this purpose, cochleae of adult mole rats were studied with light and electron microscopy. Inner hair cells throughout the cochlea, and outer hair cells in the basal (high-frequency) portion of the cochlea, were similar in structure to those seen in other mammals. In contrast, outer hair cells in the apical (low-frequency) portion displayed unique structural features. These features resembled the structure of inner hair cells or immature outer hair cells. The innervation of outer hair cells was most uncommon, in that classical medial efferent innervation was not found throughout the cochlear spiral.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/50050/1/903140211_ftp.pd

Quantitative morphological analysis of the sensory epithelium of the starling and pigeon basilar papilla

Several features of bird basilar papilla morphology were quantitatively studied in the starling and the pigeon in order to attempt a structure-function correlation. We confirmed and quantified several findings from earlier studies, but also obtained results contradictory to previous reports. The greatest discrepancies concerned the pattern of hair cell orientation. By including the results from other investigations, we describe a 'typical' avian basilar papilla and on this basis the specializations within individual species. These morphological specializations are discussed in the context of the available physiological data