Gap in Noise Induced Auditory Brainstem Responses in Guinea Pigs at Different Developmental Stages

ZHANG Ning; LIN Ying; XU Fei

doi:10.3969/j.issn.1672-2922.2023.05.012

Abstract：Objective To report changes of gap in noise induced auditory brainstem responses(GIN ABRs)in guinea pigs at different developmental stages and compare tone burst auditory brainstem responses(tb-ABRs)with GIN ABRs to investigate the effect of auditory system development on GIN ABR,so as to lay a foundation for the clinical application of this test.Methods tb-ABRs were tested in guinea pigs(2 and 9-weeks-old)at different frequencies(8,12,16 and 24 kHz)and silent intervals(0,1,2,4,8,16 and 32 ms).Thresholds,latencies and amplitudes of waves Ⅰ,Ⅲ and Ⅳ,as well as latency shift,wave amplitude and recovery ratio in GIN ABR,were all recorded.Results tb-ABR thresholds at 9-weeks were lower than at 2-weeks at 8 kHz(P<0.01),with latency of wave Ⅲ also shorter than at 2-weeks for all tested frequencies at 80 and 50 dB SPL(P<0.05)and amplitude of wave Ⅰ significantly lower than at 2-week at 80 dB SPL(P<0.05).At both 9 and 2-weeks,GIN ABR latency shift and wave amplitude decreased as the dura-tion of silent gap increased,while recovery ratio and wave amplitude induced by NB2 increased.When the duration of silent interval was 2,8 and 16 ms,P3 latency shift at 9-weeks was significantly shorter than at 2-weeks(P<0.05),while recovery ratio of P4 wave was significantly higher than that at 2-weeks(P<0.05).Conclusion There are differences in tone burst ABRs and gap in noise ABRs between 2-week-old and 9-week-old guinea pigs,which can be used as a model for studying development of auditory function.GIN ABR test can be used as a supplementary tool to evaluate auditory function.