Action potential timing precision in dorsal cochlear nucleus pyramidal cells.
Action potential timing precision in dorsal cochlear nucleus pyramidal cells.
复制标题
耳蜗背核锥体细胞动作电位计时精度。
DOI：
10.1152/jn.00469.2006
复制
发表时间：
2007
影响因子：
2.5
通讯作者：
Manis,PaulB
中科院分区：
文献类型：
--
作者：
Street,SarahE;Manis,PaulB
许多关于耳蜗背核(DCN)的研究都集中在声刺激的平均放电频率的表征上。然而，最近的研究强调了棘波计时在信息编码中的作用。我们试图确定DCN锥体细胞是否可能采用类似的策略，以及内在兴奋性在多大程度上调节棘波的计时。在制备脑片的过程中，将高斯分布的低通噪声电流注入锥体细胞。基于混洗的自相关分析被用来计算跨试验的峰时间的相关指数。噪声导致细胞以时间精度(SD≅1-2 ms)和高重复性发射。增加噪声的变异系数改善了棘波序列的重复性，而增加神经元的放电率则降低了神经元对可预测的棘波模式的反应能力。模拟抑制性突触后电位叠加在噪声刺激上，在300ms内增强了棘波计时，尽管在前100ms增强最大。我们还发现，锥体神经元群体对相同的噪声刺激做出了相关的棘波序列反应，这表明接受共享输入的DCN中的神经元集合可以以类似的时间放电。这些结果支持这一假设，即尖峰定时可能是DCN中信息编码的一个重要方面。
Many studies of the dorsal cochlear nucleus (DCN) have focused on the representation of acoustic stimuli in terms of average firing rate. However, recent studies have emphasized the role of spike timing in information encoding. We sought to ascertain whether DCN pyramidal cells might employ similar strategies and to what extent intrinsic excitability regulates spike timing. Gaussian distributed low-pass noise current was injected into pyramidal cells in a brain slice preparation. The shuffled autocorrelation-based analysis was used to compute a correlation index of spike times across trials. The noise causes the cells to fire with temporal precision (SD ≅ 1–2 ms) and high reproducibility. Increasing the coefficient of variation of the noise improved the reproducibility of the spike trains, whereas increasing the firing rate of the neuron decreased the neurons' ability to respond with predictable patterns of spikes. Simulated inhibitory postsynaptic potentials superimposed on the noise stimulus enhanced spike timing for >300 ms, although the enhancement was greatest during the first 100 ms. We also found that populations of pyramidal neurons respond to the same noise stimuli with correlated spike trains, suggesting that ensembles of neurons in the DCN receiving shared input can fire with similar timing. These results support the hypothesis that spike timing can be an important aspect of information coding in the DCN.