动物造模 z-bio 2021-11-10 451

　　OBJECTIVE: To explore and compare the different damage patterns and regularities of cochlear hair cells in CBA/CaJ and C57BL/6J mice with age.

　　Method: 32 CBA/CaJ and C57BL/6J mice aged 6 months, 12 months, 18 months and 24 months were selected, 8 of each age, and the cochlea was removed under general anesthesia. Cochlear basement membrane was spread, the total cochlear inner and outer hair cell count results were input into the computer and the cochlear chart software was used to compare and statistically analyze the cochlear hair cell density of the two mouse species according to the corresponding different ages.

　　Result: CBA/CaJ mice began to show a slight loss of outer hair cells at the top of the cochlea at the age of 12 months. With the increase of age, the loss of outer hair cells continued to expand, mainly from the top to the middle, and the inner hair cells also appeared in the later period. From the age of 18 months, the loss of cochlear outer hair cells increased significantly compared with the previous age group (P<0.05). In C57BL/6J mice, the outer and inner hair cells have been lost at the bottom of the cochlea at 6 months, and the outer hair cell is mainly lost. The loss of inner hair cells was significantly increased compared with that of CBA/CaJ mice of the same age (P<0.05), and the loss of inner hair cells was significantly increased (P<0.05) compared with the previous age group of the same mouse species from 12 months of age.

　　Conclusion: CBA/CaJ mouse cochlear hair cell damage follows the pathological rule of starting from the top and bottom ends and extending to the middle, but the top hair cell damage is more serious than the bottom. C57BL/6J mouse cochlear hair cell damage follows the pathological rule that mainly starts from the bottom of the cochlea and gradually expands to the middle and top of the cochlea. Outer hair cells are damaged earlier than inner hair cells. The hair cell damage of C57BL/6J mice is earlier than that of CBA/CaJ mice. It is suggested that both mouse species can be used as animal models for senile hair cell apoptosis research, but the C57BL/6J mouse model is more suitable for short-term observation and research. The difference in hair cell changes between the two may be related to whether the Cdh23 gene is mutated or missing related.