Tadros Sherif F, D'Souza Mary, Zettel Martha L, Zhu XiaoXia, Lynch-Erhardt Martha, Frisina Robert D
Department of Otolaryngology, University of Rochester School of Medicine & Dentistry, Rochester, NY 14642-8629, USA.
Neurobiol Aging. 2007 Jul;28(7):1112-23. doi: 10.1016/j.neurobiolaging.2006.05.021. Epub 2006 Jul 5.
Serotonin (5-HT) is a monoamine neurotransmitter. Serotonin may modulate afferent fiber discharges in the cochlea, inferior colliculus (IC) and auditory cortex. Specific functions of serotonin are exerted upon its interaction with specific receptors; one of those receptors is the serotonin 2B receptor. The aim of this study was to investigate the differences in gene expression of serotonin 2B receptors with age in cochlea and IC, and the possible correlation between gene expression and functional hearing measurements in CBA/CaJ mice. Immunohistochemical examinations of protein expression of IC in mice of different age groups were also performed. Gene expression results showed that serotonin 2B receptor gene was upregulated with age in both cochlea and IC. A significant correlation between gene expression and functional hearing results was established. Immunohistochemical protein expression studies of IC showed more serotonin 2B receptor cells in old mice relative to young adult mice, particularly in the external nucleus. We conclude that serotonin 2B receptors may play a role in the pathogenesis of age-related hearing loss.
血清素（5-羟色胺，5-HT）是一种单胺类神经递质。血清素可能会调节耳蜗、下丘（IC）和听觉皮层的传入纤维放电。血清素的特定功能是通过其与特定受体的相互作用来实现的；其中一种受体是血清素2B受体。本研究的目的是调查CBA/CaJ小鼠耳蜗和IC中血清素2B受体基因表达随年龄的差异，以及基因表达与功能性听力测量之间的可能相关性。还对不同年龄组小鼠的IC蛋白表达进行了免疫组织化学检查。基因表达结果显示，血清素2B受体基因在耳蜗和IC中均随年龄上调。基因表达与功能性听力结果之间建立了显著相关性。IC的免疫组织化学蛋白表达研究显示，老年小鼠相对于年轻成年小鼠有更多的血清素2B受体细胞，特别是在外侧核。我们得出结论，血清素2B受体可能在年龄相关性听力损失的发病机制中起作用。
