RESUMO
Objective To study the auditory brainstem response (ABR) of normal adult CBA,C57BL,Kunming and 129 mice and analyze the ABR thresholds and latencies in order to obtain normal values and standardized testing process,thereby providing important reference for future auditory hearing research in mouse.Methods Six -week-old normal mice of CBA,C57BL,Kunming and 129(each strain containing 20 ears of 20 mice) were used in this study.ABR test with both the click and tone burst were carried on.The incidence of each wave and the thresholds and latencies of various strains of mice were recorded.Results For these four strains of mice,wave Ⅱ had the highest occurrence rate and was used to determine the thresholds.Four strains of mice all were sensitive to the sound at 8,12,16 kHz,most to 12 kHz.Under anesthesia condition,the latency of each ABR wave prolonged as testing time increase,especially the waves Ⅲ ～ V which reflected the functions of the part near the cerebral center.Conclusion Under anesthesia state,for these four strains of mice,wave Ⅱ has the highest occurrence rate and is used to determine the threshold.We determine the intensity level at which Wave Ⅱ just appeared as the ABR threshold.The stain of CBA mice is the best one to establish an animal model related to hearing function research because ABR of the other three strains are not stable as the CBA mice.Wave SP can reflect the hair cell functions indirectly.