Restricted loss of olivocochlear but not vestibular efferent neurons in the senescent gerbil (Meriones unguiculatus)
Restricted loss of olivocochlear but not vestibular efferent neurons in the senescent gerbil (Meriones unguiculatus)
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DOI：
10.3389/fnagi.2015.00004
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发表时间：
2015-02-13
影响因子：
4.8
通讯作者：
Grothe, Benedikt
中科院分区：
文献类型：
--
作者：
Radtke-Schuller, Susanne;Seeler, Sabine;Grothe, Benedikt
听力退化和眩晕是与年龄相关的听觉和前庭疾病的症状，反映了外周和中枢神经系统的多因素变化，其相互作用在很大程度上尚不清楚。前庭和听觉传出胆碱能投射起源于脑干的两侧，对外周感觉器官施加反馈控制，并调节感觉加工。我们研究了年龄相关的变化，在听觉和前庭传出系统的评估数量的胆碱能传出神经元在年轻的成年和老年沙鼠，并在胆碱能三叉神经元作为控制传出不相关的内耳。我们观察到一个显着的损失，橄榄耳蜗（OC）神经元在老年人相比，年轻的成年动物，而外侧上级橄榄（LSO）细胞的总数并没有减少老化。虽然外侧和内侧橄榄耳蜗（MOC）神经元的损失是均匀和平等的两侧的大脑，有频率相关的差异内的外侧橄榄耳蜗（MOC）神经元，其中下降更大的内侧肢体的上级橄榄核（高频表示）比外侧肢体（中低频表示）。与此相反，无论是前庭传出神经元的数量，也不是运动三叉神经元的人口显着减少老年动物。这些观察结果表明不同的影响，各自的胆碱能传出脑干系统的老化。
Degeneration of hearing and vertigo are symptoms of age related auditory and vestibular disorders reflecting multrfactorial changes in the peripheral and central nervous system whose interplay remains largely unknown. Originating bilaterally in the brain stem, vestibular and auditory efferent cholinergic projections exert feedback control on the peripheral sensory organs, and modulate sensory processing. We studied age-related changes in the auditory and vestibular efferent systems by evaluating number of cholinergic efferent neurons in young adult and aged gerbils, and in cholinergic trigeminal neurons serving as a control for efferents not related to the inner ear. We observed a significant loss of olivocochlear (OC) neurons in aged compared to young adult animals, whereas the overall number of lateral superior olive (LSO) cells was not reduced in aging. Although the loss of lateral and medial olivocochlear (MOC) neurons was uniform and equal on both sides of the brain, there were frequency-related differences within the lateral olivocochlear (LOC) neurons, where the decline was larger in the medial limb of the superior olivary nucleus (high frequency representation) than in the lateral limb (middle-to-low frequency representation). In contrast, neither the number of vestibular efferent neurons, nor the population of motor trigeminal neurons were significantly reduced in the aged animals. These observations suggest differential effects of aging on the respective cholinergic efferent brainstem systems.