Expression of Adaptin-2 in Different Stages of Mouse Cochlea / 听力学及言语疾病杂志

ABSTRACT

Objective To investigate the expression of adaptin-2(AP-2) in different stages of mouse coch‐lea and its probable role in the auditory generation and formation .Methods Mice were divided into 4 experimental groups by age (7 days old ,15 days old ,35 days old ,16 months old) ,which respectively represented the newborn mice ,developmental mice ,mature mice and old mice .Auditory brainstem response (ABR) ,laser scanning confocal microscopy (LSCM) ,immune-fluroscence histochemistry and qRT - PCR were used in this study .Results For the 15 days old ,35 days old ,16 months old groups ,ABR average threshold was 18 .67 ± 1 .21 dB nHL ,13 .83 ± 1 .47 dB nHL ,37 .83 ± 7 .68 dB nHL ,respectively ,for the 7 days old groups no responses were observed .The AP-2 im‐munoreactivity was found in all the stages of mice cochlea inner hair cell (IHC) cytoplasm ,especially in IHC basal part ,nearby the ribbon synapse .For the 7 days old ,15 days old ,35 days old ,16 months old groups ,immune-flu‐roscence histochemistry IMV(intensity mean value)were 190 .91 ± 17 .27 ,494 .06 ± 27 .63 ,838 .41 ± 38 .23 ,682 .65 ± 72 .22 ,respectively .For the 7 days old ,15 days old ,35 days old ,16 months old groups ,mRNA RQ(relative quantity)were 0 .53 ± 0 .09 ,1 .03 ± 0 .02 ,1 .00 ± 0 .09 ,1 .03 ± 0 .06 ,respectively .Developmental mice expressed significantly higher than those of the newborn in the AP -2 protein expression level which was measured by immuno -fluores‐cence histochemistry and qRT PCR(P 0 .05) ,but mature mice had significant advantages by immuno-fluorescence histochemistry .Conclusion AP-2 protein expression level may closely related to the au‐ditory formation and maintenance because its expression gradually increases with age in mice .