Le Prell Colleen G, Halsey Kärin, Hughes Larry F, Dolan David F, Bledsoe Sanford C
Kresge Hearing Research Institute, University of Michigan Medical School, Ann Arbor, MI 48109-0506, USA.
J Assoc Res Otolaryngol. 2005 Mar;6(1):48-62. doi: 10.1007/s10162-004-5009-2. Epub 2005 Apr 22.
We applied the dopaminergic (DA) neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) to the guinea pig cochlear perilymph. Immunolabeling of lateral olivocochlear (LOC) neurons using antibodies against synaptophysin was reduced after the MPTP treatment. In contrast, labeling of the medial olivocochlear innervation remained intact. As after brainstem lesions of the lateral superior olive (LSO), the site of origin of the LOC neurons, the main effect of disrupting LOC innervation of the cochlea via MPTP was a depression of the amplitude of the compound action potential (CAP). CAP amplitude depression was similar to that produced by LSO lesions. Latency of the N1 component of the CAP, and distortion product otoacoustic emission amplitude and adaptation were unchanged by the MPTP treatment. This technique for selectively lesioning descending LOC efferents provides a new opportunity for examining LOC modulation of afferent activity and behavioral measures of perception.
我们将多巴胺能（DA）神经毒素1-甲基-4-苯基-1,2,3,6-四氢吡啶（MPTP）应用于豚鼠耳蜗外淋巴。使用抗突触素抗体对外侧橄榄耳蜗（LOC）神经元进行免疫标记，在MPTP处理后减少。相比之下，内侧橄榄耳蜗神经支配的标记保持完整。正如外侧上橄榄核（LSO）——LOC神经元的起源部位——发生脑干损伤后一样，通过MPTP破坏耳蜗的LOC神经支配的主要作用是复合动作电位（CAP）幅度降低。CAP幅度降低与LSO损伤所产生的情况相似。MPTP处理并未改变CAP的N1成分的潜伏期、畸变产物耳声发射幅度及适应性。这种选择性损伤下行LOC传出纤维的技术为研究LOC对传入活动的调节及行为感知测量提供了新机会。
