Cholinergic Modulation of Stimulus-Specific Adaptation in the Inferior Colliculus
Cholinergic Modulation of Stimulus-Specific Adaptation in the Inferior Colliculus
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DOI：
10.1523/jneurosci.0909-15.2015
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发表时间：
2015-09-02
影响因子：
5.3
通讯作者：
Malmierca, Manuel S.
中科院分区：
文献类型：
--
作者：
Ayala, Yaneri A.;Malmierca, Manuel S.
不断变化的声环境的神经编码是一个复杂而苛刻的过程，依赖于神经活性物质的调制。下丘（IC）的一些神经元表现出"刺激特异性适应"（SSA），即，他们对重复性声音的反应减弱，但对罕见的声音却没有。以往的研究表明，乙酰胆碱（ACh）改变听觉神经元的频率响应区，因此是重要的频谱信息的编码。在这里，我们解决如何微离子电渗应用乙酰胆碱调制SSA在麻醉大鼠的IC。我们发现ACh通过增加对重复音调的反应来降低IC神经元的SSA。这种作用主要由毒蕈碱受体介导。胆碱能调制的强度取决于基线SSA水平，发挥其最大的影响，中间SSA反应跨IC细分的神经元。我们的数据表明，ACh的可用性增加施加短暂的功能变化，部分适应IC神经元，增强正在进行的刺激的感觉编码。这种效应可能有助于通过丘脑向皮质传播上升的感觉诱发传入活动。
Neural encoding of an ever-changing acoustic environment is a complex and demanding process that depends on modulation by neuroactive substances. Some neurons of the inferior colliculus (IC) exhibit "stimulus-specific adaptation" (SSA), i.e., a decrease in their response to a repetitive sound, but not to a rare one. Previous studies have demonstrated that acetylcholine (ACh) alters the frequency response areas of auditory neurons and therefore is important in the encoding of spectral information. Here, we address how microiontophoretic application of ACh modulates SSA in the IC of the anesthetized rat. We found that ACh decreased SSA in IC neurons by increasing the response to the repetitive tone. This effect was mainly mediated by muscarinic receptors. The strength of the cholinergic modulation depended on the baseline SSA level, exerting its greatest effect on neurons with intermediate SSA responses across IC subdivisions. Our data demonstrate that the increased availability of ACh exerts transient functional changes in partially adapting IC neurons, enhancing the sensory encoding of the ongoing stimulation. This effect potentially contributes to the propagation of ascending sensory-evoked afferent activity through the thalamus en route to the cortex.