RESUMO
AIM:We generated transgenic mice of NKCC1-/-(homozygous mutant),NKCC1+/-(heterozygous)and NKCC1+/+(wild-type)that have a targeted disruption in the NKCC1 gene to investigate the role of Na-K-2Cl(NKCC1)channel in auditory function of the inner ear.METHODS:Hearing threshold and endocochlear potential(EP)were measured in the NKCC1-/-,NKCC1+/-and NKCC1+/+ mice by auditory brainstem response(ABR)and EP recordings,respectively.The inner ears of the mice were removed and examined morphologically with the light microscope.RESULTS:The auditory function of NKCC1+/+ mice was normal,the mean value for ABR thresholds in response to click sound was [(23.13?3.78)dB,SPL],EP was(98?16)mV.The mean value for ABR thresholds to click sound was elevated in NKCC1+/-mice [(38.49?12.29)dB,SPL],relative to that significantly increased in NKCC1+/+ mice(P