脑干听觉诱发电位波幅比值和波峰潜伏期比值的生后变化(英文)

Postnatal changes of the amplitude ratios and peak latency ratios of brainstem auditory evoked potentials

目的探讨脑干听觉诱发电位(BAEP)波幅比值和波峰潜伏期(PL)比值的生后变化,为建立理想的动物模型奠定理论基础。方法选用SD大鼠,雌雄不拘。对照组15只成年大鼠,实验组选用3窝(共32只)新生大鼠,1个月后断乳,雌雄分笼饲养,每窝新生鼠选用5只用于实验。计算机平均叠加技术颅表记录大鼠BAEP,实验组15只新生SD大鼠,于14～70d动态观察BAEP的波幅比值和PL比值的变化。结果生后14d首次引出的BAEP的I,II,III和IV波的PL明显长于成年大鼠值,生后20d实验组的III/I,III/II,IV/I和IV/IIPL比值(2.57±0.13,1.39±0.13,3.56±0.19,1.93±0.18)明显大于成年大鼠值(2.28±0.17,1.29±0.07,3.05±0.26,1.72±0.11,t=5.713,3.315,5.110,3.903,P<0.01);随鼠龄增长,各PL逐渐缩短至成年大鼠值,PL比值逐渐变小至成年大鼠值。生后14d,BAEP的I,II,III和IV波的波幅均明显低于成年大鼠值,生后1个月内随年龄增长而递增,并明显超过成年大鼠值,然后又逐渐回降至成年大鼠值;III/II和IV/II波幅比值随鼠龄增长也有先增后降的相似变化。但II/I和IV/IIIPL比值与III/I,IV/I和IV/III波幅比值无明显生后变化。结论大鼠BAEP部分波幅比值和PL比值有显著的生后变化。

Aim To modify ideal animal model by investigating the postnatal changes of the amplitude ratios and peak latency (PL) ratios of brainstem auditory evoked potentials (BAEP).Methods Male and female SD rats were selected.Control group consisted of 15 normal adult rats, and there were total 32 rat pups in experiment group.Rats in experimental group were given up milk after one month,and then the female and male were raised in different cages,5 rats of each litter were put into experiment.BAEP were recorded at the skull surface by average summation technique of computer in SD rats.15 rat pups from three litters were put into the experiment,and the amplitude ratios and PL ratios of BAEP had been continuously studied from age 14 to 70 days.Results The PL of waveⅠ,Ⅱ,Ⅲand Ⅳof BAEP which emerged at day 14 were much greater than adult values of control group, and then shortened with age to adult ones.The PL ratios of Ⅲ/Ⅰ,Ⅲ/Ⅱ,Ⅳ/Ⅰand Ⅳ/Ⅱ(2.57±0.13,1.39±0.13,3.56±0.19,1.93±0.18) were also bigger than adult values(2.28±0.17,1.29±0.07,3.05±0.26,1.72±0.11,t=5.713,3.315,5.110,3.903,P< 0.01) in experimental group after 20 days, and then diminished gradually with age to adult ones.The amplitudes of waveⅠ,Ⅱ,Ⅲand Ⅳat day 14 were much smaller than adult values, and increased quickly with age during the first month and their peak values were much greater than adult ones,and then diminished gradually.The postnatal changes of the amplitude ratios of Ⅲ/Ⅱand Ⅳ/Ⅱwere also characterized by an earlier increase and a latter decrease. However,the PL ratios of Ⅱ/Ⅰand Ⅳ/Ⅲand the amplitude ratios of Ⅲ/Ⅰ,Ⅳ/Ⅰand Ⅳ/Ⅲhad no significant postnatal changes. Conclusion Part of the amplitude ratios and PL ratios of BAEP of rats had significant postnatal changes.