Woodruff Alan R, Sah Pankaj
Queensland Brain Institute and School of Biomedical Sciences, University of Queensland, Brisbane, Queensland 4072, Australia.
J Neurosci. 2007 Jan 17;27(3):553-63. doi: 10.1523/JNEUROSCI.3686-06.2007.
The amygdala is a temporal lobe structure that is required for processing emotional information. Polymodal sensory information enters the amygdala at the level of the basolateral amygdala (BLA) and undergoes local processing, after which the behavioral and autonomic responses that accompany emotions are initiated. Two main neuron types are present in the BLA, pyramidal-like principal neurons that use glutamate as their transmitter, and local circuit interneurons that use GABA as their transmitter. Although the properties of principal neurons are known in some detail, very little is known about the properties of BLA interneurons or the local circuits in which they are involved. Using mice in which EGFP (enhanced green fluorescent protein) is expressed under the control of the parvalbumin promoter, we characterized the properties of parvalbumin-positive interneurons in the BLA. By making recordings from interneuron-interneuron and interneuron-principal neuron pairs, we analyzed the intrinsic circuitry of the BLA. We show that parvalbumin-positive interneurons can be divided into four subtypes as defined by their firing properties. Interneurons are electrically coupled in subtype-specific networks and exhibit subtype-specific heterogeneities in their synaptic dynamics and patterns of connectivity. We propose that these properties allow networks of parvalbumin-expressing neurons to perform an array of information-processing tasks within the BLA.
杏仁核是颞叶结构，处理情绪信息时不可或缺。多模态感觉信息在基底外侧杏仁核（BLA）水平进入杏仁核并进行局部处理，之后引发伴随情绪的行为和自主反应。BLA中有两种主要神经元类型，即使用谷氨酸作为递质的锥体形主神经元，以及使用GABA作为递质的局部回路中间神经元。虽然主神经元的特性已得到一定程度的详细了解，但对于BLA中间神经元的特性或它们所参与的局部回路却知之甚少。我们利用在小白蛋白启动子控制下表达增强型绿色荧光蛋白（EGFP）的小鼠，对BLA中表达小白蛋白的中间神经元的特性进行了表征。通过记录中间神经元 - 中间神经元对和中间神经元 - 主神经元对，我们分析了BLA的内在回路。我们发现，根据放电特性，表达小白蛋白的中间神经元可分为四种亚型。中间神经元在亚型特异性网络中电耦合，并且在其突触动力学和连接模式方面表现出亚型特异性异质性。我们认为，这些特性使表达小白蛋白的神经元网络能够在BLA内执行一系列信息处理任务。
