The Gansu Zokor Myospalax Cansu Cochlear Structures

Subterranean rodents are species which were specilized by the underground environment. They show a series of changes in sense organs to adapt to the underground environment. The subterranean rodents have tuned their hearing towards lower frequencies. The kernel question of hearing is the research of cochlea activity.In order to disclose the structure of Myospalax cansu'cochlea,two groups experiments about the hearing ability of Myospalax cansu have finished, which are histological research, sanning electron micoscope research about Myospalax cansu' cochlea and stereocilia on hair cells.The results show that the cochlea structures between Myospalax cansu and other mammals are similar.It also have a typical screwy structure, and it have three and a half circles aggregately. The helix ganglions are clear to see, which including big deeply dyed cells and small shallowly dyed cells, from the bottom to the top of cochlea, the number of the helix ganglions gradually increases.Tissue treated with scanning electron microscopy, in Myospalax cansu' cochlea, the inner hair cells are arranged in a simple line, and there are about forty stereocilia on the top of inner hair cells, they are arranged in linear. At basal turn of cochlea,Outer hair cells are arranged in three rows, there are about four rows stereocilia on every outer hair cell, and there are about thirty stereocilia every row, about one hundred and twenty stereocilia every bundle.These stereocilia arranged orderly, and the length of the stereocilia heightened from inside to outer side of the stereocilia bundle gradually. Outer hair cells are longer than Inner hair cells,the length of inner stereocilia is 1μm,and the outer stereocilia is 4μm.The length of Inner hair cells is 7μm.The space between outer hair cells is small, and outer hair cells in different rows arranged inlaid. The length of outer hair cells heightened from basal turn to top turn of cochlea. Outer hair cells and the stereocilia are arranged not regular,There were less stereocilia missing at top turn and basal turn of cochlea.Inner hair cells and stereocilia assignment until caecum,and the length is stable.The results show that inner hair cells is sensitive to low frequency, which produces to the environment adaption.