Long-term cortical plasticity evoked by electric stimulation and acetylcholine applied to the auditory cortex
Long-term cortical plasticity evoked by electric stimulation and acetylcholine applied to the auditory cortex
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DOI：
10.1073/pnas.0503851102
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发表时间：
2005-06-28
影响因子：
11.1
通讯作者：
Suga, N
中科院分区：
文献类型：
--
作者：
Ma, XF;Suga, N
听觉恐惧条件反射与紧跟着的腿部电刺激不仅激活了听觉和体感系统的神经元，而且还激活了大脑许多其他区域的神经元，并引发了丘脑和皮层神经元的最佳频率（BFs）的变化，即下丘和听觉皮层（AC）的频率（耳蜗异位）图的重组。诱发长期皮层BF移位的最小必要神经因素是什么？我们发现：(1)电刺激和乙酰胆碱对交流的作用与条件反射一样，都能引起长期皮层BF移位；(h) AC的电刺激和下丘的乙酰胆碱作用均增加了皮质电刺激引起的短期丘BF位移，但不改变其为长期；（iii）由于这种短期的collcollal BF移位被阿托品阻断，长期皮质BF移位的发展变得缓慢而小。因此，引起长期皮层BF移位的最基本的神经元素是AC、皮质反馈和胆碱能核。我们目前的数据支持Gao-Suga模型，该模型假设，在多感觉丘脑核中，没有条件和非条件刺激的关联，音调刺激可以诱发短期的皮层BF转移，这些BF转移被胆碱能神经元增强并转变为长期的BF转移。
Auditory fear conditioning with tone bursts followed by electric leg stimulation activates neurons not only in the auditory and somatosensory systems but also in many other regions of the brain and elicits shifts in the best frequencies (BFs) of collicular and cortical neurons, i.e., reorganization of the frequency (cochleotopic) maps in the inferior colliculus and auditory cortex (AC). What are the neural elements minimally necessary for evoking long-term cortical BF shifts? We found that: (i) both electric stimulation and acetylcholine applied to the AC evoke the long-term cortical BF shift as does the conditioning; (h) both electric stimulation of the AC and acetylcholine applied to the inferior colliculus increase the short-term collicular BF shift evoked by the cortical electric stimulation but do not change it into long-term; and (iii) as this short-term collicular BF shift is blocked by atropine, the development of the long-term cortical BF shift becomes slow and small. Therefore, the most essential neural elements for evoking the long-term cortical BF shift are the AC, corticofugal feedback and the cholinergic nucleus. Our current data support the Gao-Suga model, which hypothesizes that the small short-term cortical BF shifts are evoked by tonal stimuli without the association of conditioned and unconditioned stimuli in the multisensory thalamic nuclei and that these BF shifts are augmented and changed into the large long-term BF shifts by cholinergic neurons.