Development of reorganization of the auditory cortex caused by fear conditioning: Effect of atropine
Development of reorganization of the auditory cortex caused by fear conditioning: Effect of atropine
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DOI：
10.1152/jn.00363.2003
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发表时间：
2003-09-01
影响因子：
2.5
通讯作者：
Suga, N
中科院分区：
文献类型：
--
作者：
Ji, WQ;Suga, N
中枢听觉系统中频率图的重组是基于听神经元的最佳频率(BF；以下称为BF移位)以及频率-响应曲线。在大型棕色蝙蝠中，先进行声刺激再进行腿部电刺激的条件反射，会引起丘脑和皮质神经元的BF移位。丘脑BF移位发展快且时间短，而皮质BF移位发展缓慢且时间长。在条件反射过程中，听觉皮质中的乙酰胆碱水平必须很高，才能形成这些BF变化。我们研究了听觉皮质应用阿托品(一种M胆碱受体的拮抗剂)对30分钟条件反射引起的清醒蝙蝠大脑皮层BF长期漂移的影响。我们发现：1)皮层BF漂移在条件反射开始后15min开始发展，在60min后逐渐增加，并达到平台期；2)皮层BF漂移在条件反射开始后从短到长的变化类似于45min；3)皮层BF漂移可以在给定的控制条件下的BF和条件反射频率之间以不同的频率平台化；4)最大BF漂移类似于条件反射开始后70min，5)乙酰胆碱在皮层BF漂移的发展中起着重要作用。它的作用类似于条件反射开始后180分钟结束。
Reorganization of the frequency map in the central auditory system is based on shifts in the best frequencies (BFs; hereafter, BF shifts), together with the frequency-response curves, of auditory neurons. In the big brown bat, conditioning with acoustic stimulation followed by electric leg-stimulation causes BF shifts of collicular and cortical neurons. The collicular BF shift develops quickly and is short term, whereas the cortical BF shift develops slowly and is long term. The acetycholine level in the auditory cortex must be high during conditioning to develop these BF shifts. We studied the effect of atropine ( an antagonist of muscarinic acetylcholine receptors) applied to the auditory cortex on the development of the long-term cortical BF shift in the awake bat caused by a 30-min conditioning session. We found 1) the cortical BF shift starts to develop similar to 15 min after the onset of the conditioning, gradually increases over 60 min, and reaches a plateau, 2) the cortical BF shift changes from short to long term similar to 45 min after the onset of the conditioning, 3) the cortical BF shift can plateau at different frequencies between the BF of a given neuron in the control condition and the frequency of the conditioning tone, 4) the maximum BF shift is determined similar to 70 min after the onset of the conditioning, and 5) acetylcholine plays an important role in the development of the cortical BF shift. Its role ends similar to 180 min after the onset of the conditioning.