The amygdala is essential for the development of neuronal plasticity in the medial geniculate nucleus during auditory fear conditioning in rats
The amygdala is essential for the development of neuronal plasticity in the medial geniculate nucleus during auditory fear conditioning in rats
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DOI：
10.1523/jneurosci.21-06-j0001.2001
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发表时间：
2001-03-15
影响因子：
5.3
通讯作者：
Goosens, KA
中科院分区：
文献类型：
--
作者：
Maren, S;Yap, SA;Goosens, KA
丘脑内侧膝状体核（MGN）和杏仁核基底外侧复合体（BLA）是介导听觉恐惧条件反射的神经回路的重要组成部分。一些研究表明，在听觉恐惧条件反射过程中，MGN和BLA的神经元都表现出尖峰放电的关联可塑性。在本研究中，我们研究是否在MGN可塑性的发展需要BLA。单个单位记录从慢性多通道电极植入在清醒和自由活动的大鼠的MGN的内侧部。大鼠接受听觉恐惧条件反射试验，其中包括白噪声条件刺激（CS）和共终止足电击无条件刺激（US）。未配对（致敏）对照组接受的试验次数与配对动物相同，但CS和US明确未配对。在恐惧条件反射之前，大鼠接受杏仁核内注射蝇蕈醇（GABA（A）受体激动剂）至海马BLA神经元或注射生理盐水载体。听觉恐惧条件反射产生了大量增加CS引起的尖峰放电的MGN和条件冻结行为的车辆处理的大鼠接受配对训练。蝇蕈醇失活的BLA严重衰减的发展条件相关的增加CS引起的尖峰放电的MGN和条件冻结的听觉CS。不成对的训练没有产生增加，无论是CS引起的尖峰放电或冻结的语气CS。这些结果表明，BLA是必不可少的可塑性在恐惧条件反射的听觉丘脑的发展。
The medial geniculate nucleus of the thalamus (MGN) and the basolateral complex of the amygdala (BLA) are critical components of the neural circuit that mediates auditory fear conditioning. Several studies indicate that neurons in both the MGN and BLA exhibit associative plasticity of spike firing during auditory fear conditioning. In the present study, we examined whether the development of plasticity in the MGN requires the BLA. Single units were recorded from chronic multichannel electrodes implanted in the medial division of the MGN of conscious and freely moving rats. Rats received auditory fear conditioning trials, which consisted of a white-noise conditional stimulus (CS) and a co-terminating footshock unconditional stimulus (US). Unpaired (sensitization) controls received the same number of trials as paired animals, but the CS and US were explicitly unpaired. Before fear conditioning, rats received either an intra-amygdala infusion of muscimol, a GABA(A) receptor agonist, to inactivate BLA neurons or an infusion of the saline vehicle. Auditory fear conditioning produced a substantial increase in both CS-elicited spike firing in the MGN and conditional freezing behavior in vehicle-treated rats receiving paired training. Muscimol inactivation of the BLA severely attenuated the development of both conditioning-related increases in CS-elicited spike firing in the MGN and conditional freezing to the auditory CS. Unpaired training did not yield increases in either CS-elicited spike firing or freezing to the tone CS. These results reveal that the BLA is essential to the development of plasticity in the auditory thalamus during fear conditioning.