Dendritic modulation of burst-like firing in sensory neurons
Dendritic modulation of burst-like firing in sensory neurons
复制标题
DOI：
10.1152/jn.2001.85.1.10
复制
发表时间：
2001-01-01
影响因子：
2.5
通讯作者：
Nguyenkim, J
中科院分区：
文献类型：
--
作者：
Bastian, J;Nguyenkim, J
本文报道了在体弱电鱼感觉侧线叶内感觉神经元--感觉侧线叶（ELL）锥体细胞自发放电特性的变异性。我们发现，这些细胞的自发放电频率，措施的尖峰列车的规律性（interspike间隔变异系数），以及这些细胞产生动作电位爆发的趋势与细胞的顶端树突状乔木的大小。我们还表明，爆裂行为可能会受到影响或控制的下行输入从更高的中心，提供兴奋性和抑制性输入的锥体细胞的顶树突。金字塔细胞被分类为“突发性”或“nonbursty”根据是否尖峰列车偏离显着的预期属性的随机（泊松）尖峰列车相同的平均放电频率，并在突发性细胞的情况下，最大的突发内的脉冲串interspike间隔特性的突发被确定。确定每个细胞产生高于泊松尖峰序列预期水平的爆发的概率，并与自发放电频率和树突形态相关。具有大顶端树突的锥体细胞具有较低的自发活动率和较高的产生高于预期水平的爆发的可能性，而具有较小顶端树突的细胞以较高的频率发射，并且不那么突发。阻断非N-甲基-D-天冬氨酸（非-NMDA）对这些细胞的顶端树突和局部抑制性中间神经元的突触输入的作用，显著降低了自发发生的尖峰爆发和细胞内注射的超极化电流模仿了这种作用。结果表明，突发发射的ELL锥体细胞可能是在下降控制下，允许活动的电感觉反馈通路的影响放电特性的感觉神经元的早期处理层次。
This report describes the variability of spontaneous firing characteristics of sensory neurons, electrosensory lateral line lobe (ELL) pyramidal cells, within the electrosensory lateral line lobe of weakly electric fish in vivo. We show that these cells' spontaneous firing frequency, measures of spike train regularity (interspike interval coefficient of variation), and the tendency of these cells to produce bursts of action potentials are correlated with the size of the cell's apical dendritic arbor. We also show that bursting behavior may be influenced or controlled by descending inputs from higher centers that provide excitatory and inhibitory inputs to the pyramidal cells' apical dendrites. Pyramidal cells were classified as "bursty" or "nonbursty" according to whether or not spike trains deviated significantly from the expected properties of random (Poisson) spike trains of the same average firing frequency, and, in the case of bursty cells, the maximum within-burst interspike interval characteristic of bursts was determined. Each cell's probability of producing bursts above the level expected for a Poisson spike train was determined and related to spontaneous firing frequency and dendritic morphology. Pyramidal cells with large apical dendritic arbors have lower rates of spontaneous activity and higher probabilities of producing bursts above the expected level, while cells with smaller apical dendrites fire at higher frequencies and are less bursty. The effect of blocking non-N-methyl-D-aspartate (non-NMDA) glutamatergic synaptic inputs to the apical dendrites of these cells, and to local inhibitory interneurons, significantly reduced the spontaneous occurrence of spike bursts and intracellular injection of hyperpolarizing current mimicked this effect. The results suggest that bursty firing of ELL pyramidal cells may be under descending control allowing activity in electrosensory feedback pathways to influence the firing properties of sensory neurons early in the processing hierarchy.