Estimated distribution of specific membrane resistance in hippocampal CA1 pyramidal neuron
Estimated distribution of specific membrane resistance in hippocampal CA1 pyramidal neuron
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DOI：
10.1016/j.brainres.2006.09.095
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发表时间：
2006-12
期刊：
影响因子：
2.9
通讯作者：
T. Omori;T. Aonishi;H. Miyakawa;M. Inoue;M. Okada
中科院分区：
文献类型：
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作者：
T. Omori;T. Aonishi;H. Miyakawa;M. Inoue;M. Okada
树突状细胞膜的特性在突触整合中起着重要的作用。特别是，膜特性之一的比膜电阻在单个神经元中是不均匀分布的，尽管比膜电阻的空间分布尚不清楚。为了揭示其在树突的不均匀性，我们估计了在一个单一的神经元的特定膜电阻的空间分布，基于电压成像数据，观察光学海马CA 1切片。作为光学记录的数据，我们使用了树突中的阈下兴奋性突触后电位的双向传播，这在均匀特定膜电阻的情况下是无法再现的。通过对具有非均匀性比膜电阻的多室模型进行数值模拟，我们估计分布服从阶跃函数;光学记录的数据一致地再现了远端顶端树突处比膜电阻急剧下降的分布，该分布发生在距离索马300−500 μm处。在估计的分布中，远侧的比膜电阻小于约103Ω cm 2，而近侧的电阻大于约104Ω cm 2。提示海马CA 1区锥体神经元远侧顶树突的比膜电阻显著降低。
It has been suggested that dendritic membrane properties play an important role in a synaptic integration. In particular, the specific membrane resistance, one of membrane properties, has been reported to be non-uniformly distributed in a single neuron, although the spatial distribution of the specific membrane resistance is still unclear. To reveal its non-uniformity in dendrite, we estimated the spatial distribution of specific membrane resistance in a single neuron, based on voltage imaging data, observed optically in hippocampal CA1 slices. As the optically recorded data, we used bi-directional propagations of subthreshold excitatory postsynaptic potentials in dendrite, which were not be reproduced numerically with uniform-specific membrane resistance. By numerical simulations for multi-compartment models with non-uniformity of specific membrane resistance, we estimated that the distribution obeys a step function; the optically recorded data were consistently reproduced for the distribution with a steep decrease in the specific membrane resistance at the distal apical dendrite, which occurs 300−500 μm away from the soma. In the estimated distribution, the specific membrane resistance at the distal side is less than about 103Ωcm2, whereas the resistance at the proximal side is greater than about 104Ωcm2. This result implies that the specific membrane resistance decreases drastically at the distal apical dendrite in hippocampal CA1 pyramidal neuron.