Samsonovich Alexei V, Ascoli Giorgio A
Krasnow Institute for Advanced Study and Department of Psychology, George Mason University, Fairfax, VA 22030, USA.
Proc Natl Acad Sci U S A. 2006 Jan 31;103(5):1569-74. doi: 10.1073/pnas.0510057103. Epub 2006 Jan 17.
Neurons have significant potential for the homeostatic regulation of a broad range of functional features, from gene expression to synaptic excitability. In this article, we show that dendritic morphology may also be under intrinsic homeostatic control. We present the results from a statistical analysis of a large collection of digitally reconstructed neurons, demonstrating that fluctuations in dendritic size in one given portion of a neuron are systematically counterbalanced by the remaining dendrites in the same cell. As a result, the total dendritic measure (e.g., number of branches, length, and surface area) of each neuron in a given morphological class is, on average, significantly less random than would be expected if trees (and their parts) were regulated independently during development. This observation is general across scales that range from gross basal/apical subdivisions to individual branches and bifurcations, and its statistical significance is robust among various brain regions, cell types, and experimental conditions. Given the pivotal dendritic role in signal integration, synaptic plasticity, and network connectivity, these findings add a dimension to the functional characterization of neuronal homeostasis.
神经元在从基因表达到突触兴奋性等广泛功能特征的稳态调节方面具有巨大潜力。在本文中，我们表明树突形态也可能受到内在稳态控制。我们展示了对大量数字重建神经元进行统计分析的结果，表明神经元给定部分的树突大小波动会被同一细胞中的其余树突系统地抵消。因此，在给定形态类别的每个神经元的总树突测量值（例如分支数量、长度和表面积）平均而言，其随机性显著低于在发育过程中树突（及其部分）独立调节时的预期。这一观察结果在从大体的基底/顶端细分到单个分支和分叉的各个尺度上都是普遍存在的，并且其统计显著性在不同脑区、细胞类型和实验条件下都很稳健。鉴于树突在信号整合、突触可塑性和网络连接性方面的关键作用，这些发现为神经元稳态的功能表征增添了一个维度。
