Dorsal Cochlear Nucleus of the Rat: Representation of Complex Sounds in Ears Damaged by Acoustic Trauma.
Dorsal Cochlear Nucleus of the Rat: Representation of Complex Sounds in Ears Damaged by Acoustic Trauma.
复制标题
大鼠耳蜗背核：受声学创伤损伤的耳朵中复杂声音的表示。
DOI：
10.1007/s10162-015-0522-z
复制
发表时间：
2015
期刊：
影响因子：
--
通讯作者：
Young,EricD
中科院分区：
文献类型：
--
作者：
Li,Yang;Ropp,Tessa-JonneF;May,BradfordJ;Young,EricD
声损伤损害耳蜗，但其次修改中枢听觉系统的电路。变化包括抑制性神经递质系统的减少、突触回路的变性和重新布线以及神经活动的变化。关于这些变化对复杂声音的表现的影响，我们知之甚少。在这里，我们显示的数据，从耳蜗背核（DCN）的大鼠与中度高频听力损失后的声创伤。单神经元记录用于估计神经元感受野的组织、抑制和兴奋的平衡以及复杂宽带刺激的频谱的表示。复杂的刺激有随机的频谱形状（RSS），并与一个模型，允许代表性的质量和它的线性程度进行估计的响应。大鼠DCN神经元的音调反应图与以前研究的其他物种相似，表明该核的一般组织相同。声损伤后出现异常反应类型。这些可以被解释为反映听觉神经纤维的调谐退化加上DCN中抑制性输入的丧失。异常类型在暴露后的较晚时间（103-376天）更为普遍，但并不显著。在创伤后神经元中抑制变得较弱，保留抑制反应，但在许多神经元中也消失。质量的频谱形状的代表性，测量灵敏度的光谱形状的RSS刺激，减少创伤后，事实上，神经元异常反应类型的反应主要是整体刺激水平，而不是频谱形状。
Acoustic trauma damages the cochlea but secondarily modifies circuits of the central auditory system. Changes include decreases in inhibitory neurotransmitter systems, degeneration and rewiring of synaptic circuits, and changes in neural activity. Little is known about the consequences of these changes for the representation of complex sounds. Here, we show data from the dorsal cochlear nucleus (DCN) of rats with a moderate high-frequency hearing loss following acoustic trauma. Single-neuron recording was used to estimate the organization of neurons’ receptive fields, the balance of inhibition and excitation, and the representation of the spectra of complex broadband stimuli. The complex stimuli had random spectral shapes (RSSs), and the responses were fit with a model that allows the quality of the representation and its degree of linearity to be estimated. Tone response maps of DCN neurons in rat are like those in other species investigated previously, suggesting the same general organization of this nucleus. Following acoustic trauma, abnormal response types appeared. These can be interpreted as reflecting degraded tuning in auditory nerve fibers plus loss of inhibitory inputs in DCN. Abnormal types are somewhat more prevalent at later times (103–376 days) following the exposure, but not significantly so. Inhibition became weaker in post-trauma neurons that retained inhibitory responses but also disappeared in many neurons. The quality of the representation of spectral shape, measured by sensitivity to the spectral shapes of RSS stimuli, was decreased following trauma; in fact, neurons with abnormal response types responded mainly to overall stimulus level, and not spectral shape.