Nagase Shigeyo, Mukaida Masahiro, Miller Josef M, Altschuler Richard A
Kresge Hearing Research Institute, Department of Otolaryngology, University of Michigan, Ann Arbor, MI 48109, USA.
J Neurocytol. 2003 May;32(4):353-61. doi: 10.1023/B:NEUR.0000011329.64948.82.
The influence of neonatal deafness on cochlear electrically evoked Fos expression in the auditory brainstem was examined. Newborn rats were deafened by systemic injection of kanamycin, 1 mg/g daily for 12 days. At 4, 5, 6 or 8 weeks of age, these animals received cochlear electrical stimulation with a basal monopolar electrode for 90 minutes. Age-matched untreated control animals received similar stimulation. Experimental and control animals were assessed for spiral ganglion cell densities and Fos immunoreactive staining in the central nucleus of the inferior colliculus. Spiral ganglion cell assessments showed significant decreases in spiral ganglion cell densities in deafened rats compared to age-matched controls, at 5 weeks of age in lower turns and 6 and 8 weeks in all turns. Cochlear electrical stimulation induced Fos immunoreactive staining in the nucleus of auditory brain stem neurons in treatment and control groups. A significantly greater number of Fos immunoreactive neurons was found in the contralateral central nucleus of inferior colliculus in 5, 6 and 8 week old deafened animals compared to age-matched controls. The increases were larger with a longer duration of deafness. These results suggest that there are changes in auditory processing as a consequence of neonatal deafness.
研究了新生儿耳聋对听觉脑干中耳蜗电诱发Fos表达的影响。新生大鼠通过全身注射卡那霉素致聋，剂量为每日1mg/g，持续12天。在4、5、6或8周龄时，这些动物用基底单极电极接受90分钟的耳蜗电刺激。年龄匹配的未处理对照动物接受类似刺激。对实验动物和对照动物进行螺旋神经节细胞密度评估以及下丘中央核的Fos免疫反应性染色评估。螺旋神经节细胞评估显示，与年龄匹配的对照相比，致聋大鼠的螺旋神经节细胞密度显著降低，在5周龄时在下转中出现，在6周和8周龄时在所有转中均出现。耳蜗电刺激在治疗组和对照组的听觉脑干神经元核中诱导了Fos免疫反应性染色。与年龄匹配的对照相比，在5、6和8周龄的致聋动物的对侧下丘中央核中发现了显著更多的Fos免疫反应性神经元。耳聋持续时间越长，增加幅度越大。这些结果表明，新生儿耳聋会导致听觉处理发生变化。
