Jin Dezhe Z, Ramazanoğlu Fethi M, Seung H Sebastian
Department of Physics, The Pennsylvania State University, 104 Davey Lab, University Park, PA 16802, USA.
J Comput Neurosci. 2007 Dec;23(3):283-99. doi: 10.1007/s10827-007-0032-z. Epub 2007 Apr 18.
Avian brain area HVC is known to be important for the production of birdsong. In zebra finches, each RA-projecting neuron in HVC emits a single burst of spikes during a song motif. The population of neurons is activated in a precisely timed, stereotyped sequence. We propose a model of these burst sequences that relies on two hypotheses. First, we hypothesize that the sequential order of bursting is reflected in the excitatory synaptic connections between neurons. Second, we propose that the neurons are intrinsically bursting, so that burst duration is set by cellular properties. Our model generates burst sequences similar to those observed in HVC. If intrinsic bursting is removed from the model, burst sequences can also be produced. However, they require more fine-tuning of synaptic strengths, and are therefore less robust. In our model, intrinsic bursting is caused by dendritic calcium spikes, and strong spike frequency adaptation in the soma contributes to burst termination.
已知鸟类脑区HVC对鸟鸣的产生很重要。在斑胸草雀中，HVC中每个投射到RA的神经元在一个歌曲主题期间会发出单个脉冲串。神经元群体以精确计时的、刻板的顺序被激活。我们提出了一个依赖于两个假设的这些脉冲串序列模型。首先，我们假设脉冲发放的顺序在神经元之间的兴奋性突触连接中得到体现。其次，我们提出神经元具有内在的脉冲发放特性，因此脉冲串持续时间由细胞特性设定。我们的模型生成的脉冲串序列与在HVC中观察到的相似。如果从模型中去除内在脉冲发放特性，也能产生脉冲串序列。然而，它们需要对突触强度进行更多的微调，因此稳健性较差。在我们的模型中，内在脉冲发放是由树突状钙峰引起的，而胞体中强烈的脉冲频率适应有助于脉冲串的终止。
