大脑中决定序列生成的神经机制的性质仍是神经科学中一个没有得到回答的基本问题。鸣禽大脑中运动前区中的单个神经元能根据鸣叫声的动态发出协调的、在时间上精确的脉冲，因此这种鸟为这方面的研究提供了一个理想模型。
现在，Long等人报告了一个技术上的“绝活”：对鸣叫的鸟的HVC神经元进行细胞内记录，这使他们能够验证关于脉冲产生的模型。他们发现，在脉冲发生前5-10毫秒，膜电势迅速去极化。这个发现与HVC神经元形成突触连接链的模型是一致的。（生物谷Bioon.com）
生物谷推荐英文摘要：
Nature doi:10.1038/nature09514
Support for a synaptic chain model of neuronal sequence generation
Michael A. Long,Dezhe Z. Jin& Michale S.
In songbirds, the remarkable temporal precision of song is generated by a sparse sequence of bursts in the premotor nucleus HVC. To distinguish between two possible classes of models of neural sequence generation, we carried out intracellular recordings of HVC neurons in singing zebra finches (Taeniopygia guttata). We found that the subthreshold membrane potential is characterized by a large, rapid depolarization 5–10 ms before burst onset, consistent with a synaptically connected chain of neurons in HVC. We found no evidence for the slow membrane potential modulation predicted by models in which burst timing is controlled by subthreshold dynamics. Furthermore, bursts ride on an underlying depolarization of ~10-ms duration, probably the result of a regenerative calcium spike within HVC neurons that could facilitate the propagation of activity through a chain network with high temporal precision. Our results provide insight into the fundamental mechanisms by which neural circuits can generate complex sequential behaviours.
