Postnatal Development of Dendritic Synaptic Integration in Rat Neocortical Pyramidal Neurons
Postnatal Development of Dendritic Synaptic Integration in Rat Neocortical Pyramidal Neurons
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DOI：
10.1152/jn.00083.2009
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发表时间：
2009-08-01
影响因子：
2.5
通讯作者：
Williams, Stephen R.
中科院分区：
文献类型：
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作者：
Atkinson, Susan E.;Williams, Stephen R.
大鼠新皮质锥体神经元树突突触整合的发育。中国生物医学工程学报（英文版），2009。2009年5月20日首次发表；doi: 10.1152 / jn.00083.2009。第5层（L5）锥体神经元的树突树横跨新皮质层，允许皮质内和皮质外突触输入的整合。本研究通过对大鼠L5锥体神经元体细胞和远端根尖树突的全细胞同时记录，研究了L5锥体神经元在出生后的整合性发育。在幼龄（P9-10）神经元中，顶端树突兴奋性突触输入通过在动作电位产生的轴突位置有效地汇总，有力地驱动动作电位输出。相比之下，在成熟的（P25-29）神经元中，顶端树突兴奋性输入在动作电位产生部位几乎没有直接去极化，而是在顶端树突树中局部整合，导致树突尖峰的产生。因此，在出生后的第一个月，由树突尖峰驱动的动作电位的比例急剧增加。L5锥体神经元整合操作的发育重塑是由细胞附着斑块中发现的顶端树突超极化激活环核苷酸（HCN）门控通道密度增加10倍或HCN通道异构体HCN1的免疫染色所控制的。因此，树突顶端HCN通道密度的年龄依赖性增加确保了L5锥体神经元从紧凑的时间整合者发展为区隔化的基底和树突顶端突触输入整合者。
Atkinson SE, Williams SR. Postnatal development of dendritic synaptic integration in rat neocortical pyramidal neurons. J Neurophysiol 102: 735-751, 2009. First published May 20, 2009; doi:10.1152/jn.00083.2009. The dendritic tree of layer 5 (L5) pyramidal neurons spans the neocortical layers, allowing the integration of intra-and extracortical synaptic inputs. Here we investigate the postnatal development of the integrative properties of rat L5 pyramidal neurons using simultaneous whole cell recording from the soma and distal apical dendrite. In young (P9-10) neurons, apical dendritic excitatory synaptic input powerfully drove action potential output by efficiently summating at the axonal site of action potential generation. In contrast, in mature (P25-29) neurons, apical dendritic excitatory input provided little direct depolarization at the site of action potential generation but was integrated locally in the apical dendritic tree leading to the generation of dendritic spikes. Consequently, over the first postnatal month the fraction of action potentials driven by apical dendritic spikes increased dramatically. This developmental remodeling of the integrative operations of L5 pyramidal neurons was controlled by a > 10-fold increase in the density of apical dendritic Hyperpolarization-activated cyclic nucleotide (HCN)-gated channels found in cell-attached patches or by immunostaining for the HCN channel isoform HCN1. Thus an age-dependent increase in apical dendritic HCN channel density ensures that L5 pyramidal neurons develop from compact temporal integrators to compartmentalized integrators of basal and apical dendritic synaptic input.