Electrophysiological characterization and computational models of HVC neurons in the zebra finch
Electrophysiological characterization and computational models of HVC neurons in the zebra finch
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DOI：
10.1152/jn.00162.2013
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发表时间：
2013-09-01
影响因子：
2.5
通讯作者：
Bertram, Richard
中科院分区：
文献类型：
--
作者：
Daou, Arij;Ross, Matthew T.;Bertram, Richard
在哺乳动物前运动皮层的鸟类类似物内的HVC核（专有名称）通过运动通路产生刻板的指令，导致鸣禽精确的学习发声。组成HVC神经元的电生理表征是建立模型以理解HVC功能的重要要求。HVC包含三个神经群：投射到RA（arcopallium的鲁棒核）的神经元，投射到X区（鸟类基底神经节）的神经元和中间神经元。这三个群体与特定的兴奋性和抑制性连接模式相互关联，并且它们在体内和体外都具有特征性模式。我们在脑切片内对HVC神经元进行了全细胞电流钳记录，以检查其内在的放电特性，并确定哪些离子电流是其特征放电模式的原因。我们还为不同的神经元开发了基于电导的模型，并使用我们大脑切片工作的数据校准了模型。然后，这些模型被用来预测负责对刺激的不同反应的离子电流的组成。然后，使用药理学操作在切片中测试和验证这些预测。该模型和切片工作突出了超极化激活的内向电流（I-h）、低阈值T型Ca 2+电流（ICa-T）、A型K+电流（I-A）、Ca 2+激活的K+电流（I-SK）和Na+依赖的K+电流（I-KNa）在驱动三个HVC神经元群体中观察到的特征性神经模式中的作用。其结果是一个改进的表征HVC神经元负责鸣禽的歌曲生产。
The nucleus HVC (proper name) within the avian analog of mammal premotor cortex produces stereotyped instructions through the motor pathway leading to precise, learned vocalization by songbirds. Electrophysiological characterization of component HVC neurons is an important requirement in building a model to understand HVC function. The HVC contains three neural populations: neurons that project to the RA (robust nucleus of arcopallium), neurons that project to Area X (of the avian basal ganglia), and interneurons. These three populations are interconnected with specific patterns of excitatory and inhibitory connectivity, and they fire with characteristic patterns both in vivo and in vitro. We performed whole cell current-clamp recordings on HVC neurons within brain slices to examine their intrinsic firing properties and determine which ionic currents are responsible for their characteristic firing patterns. We also developed conductance-based models for the different neurons and calibrated the models using data from our brain slice work. These models were then used to generate predictions about the makeup of the ionic currents that are responsible for the different responses to stimuli. These predictions were then tested and verified in the slice using pharmacological manipulations. The model and the slice work highlight roles of a hyperpolarization-activated inward current (I-h), a low-threshold T-type Ca2+ current (ICa-T), an A-type K+ current (I-A), a Ca2+ activated K+ current (I-SK), and a Na+-dependent K+ current (I-KNa) in driving the characteristic neural patterns observed in the three HVC neuronal populations. The result is an improved characterization of the HVC neurons responsible for song production in the songbird.