强脉冲噪声暴露豚鼠耳蜗传出神经乙酰胆碱酯酶(AChE)活性的定量分析

目的强脉冲噪声暴露后,豚鼠耳蜗听神经复合动作电位(Cochlear action potential,CAP)阀值提高,按不同的阈移分为五组:0~5 dB(6只);10~15 dB(5只);20~25 dB(11只);30~35 dB(7只);55~60 dB(5只)以及正常对照组6只豚鼠。方法用Image-pro plus图象分析软件,人机交互对话方式对各组耳蜗铺片观察耳蜗传出神经末梢处病变的长度、传出神经末梢数目以及乙酰胆碱酯酶(AChE)活性(以灰度表示)进行测量。结果不同阈移组间耳蜗病变长度差异均有显著性或极显著性;各实验组耳蜗传出神经末梢计数随阈移增大而减少,与对照组相比差异均有显著性;AChE灰度值变化多集中在第二圈,第二圈传出神经末梢个数与该圈AChE活性呈正相关(r=+0.75);第二圈AChE灰度值变化与CAP阈移相关,即CAP阈移愈大,AChE灰度值愈大(活性降低),反之亦然。结论生理的变化与形态学计量的变化是相一致的。

Quantitative analysis of the acetylcholinesterase activities of cochlear efferent nerve in the guinea pig after the exposure of intensive impulse noise

ObjectiveNormal group,0~5 dB,10~15 dB,20~25 dB,30~35 dB and 55~60 dB group were divided according to cochlear action potential after the exposure of intensive impulse noise.MethodsThe length of change in the efferent nerve ending,the number in the efferent nerve ending and the activity of acetylcholinesterases were measured with surface preparation and image-pro plus image analysis software.ResultsThere is significance in the length of pathological changes of cochlea in different threshold shift group.The number of efferent nerve endings in the cochlea is decreased with the increase of threshold shift in each experimental group.These changes were very significance comparing to the control group.The changes of grey degree were prominence in the second turn of cochlea.The number of the efferent nerve ending in the second turn is a positive correlation with the activity of acetylcholinesterases in that turn(r=(+0.75)).That is the changes of grey degree in the second turn of cochlea are correlation with the threshold shift of cochlear action potential(CAP).The larger the threshold shift of cochlear action potential is,the larger the changes of grey degree were,vice versa.ConclusionThe physiological changes are coincidence with the quantitative changes of the morphology.